FIELD OF THE INVENTION

The invention relates to froth flotation in mineral processing. The invention relates particularly to a system and a method for automatic collector chemical concentration control in a froth flotation process in a froth flotation system.

BACKGROUND OF THE INVENTION

An ore containing at least one valuable min ^¬ eral is processed in several stages starting from the mining of the ore. The ore is comminuted in various stages from lumps to minute particles in order to ar ^¬ rive at a particle size suitable for froth flotation. The ore lumps are first crushed to produce ore parti ^¬ cles typically sized between 250 mm and 25 mm. The crushing applies compression or impact forces. The crushed ore is processed in a slurry form in a grind- ing-classification circuit typically consisting of a primary mill and secondary mill and a hydrocyclone battery. The primary mill is usually autogenous, semi- autogenous or a rod mill, while secondary grinding is often performed in a ball mill. The ground ore is classified in a hydrocyclone in which the coarser un ^¬ derflow is returned to grinding and the finer overflow is sent to flotation. The particle sizes suitable for froth flotation range typically from 0.2 mm to 10 pm.

Ore particles may have at least one surface area of a desirable mineral which is also called a valuable mineral. In froth flotation, ore particles containing a desirable mineral a sufficient amount on their surfaces are removed from gangue . In froth flo- tation the ground ore is mixed with water to form a slurry. The slurry is treated with flotation reagents. The flotation reagents comprise at least one collector chemical. The collector chemical molecules adhere to surface areas on ore particles having the valuable mineral through an adsorption process. The collector chemical molecules form a film on the valuable mineral areas on the surface of the ore particle. The adsorp ^¬ tion may be based on, for example, electrochemical and chemical reactions, catalytic oxidation, chemisorp- tion, physisorption, or a combination of chemisorption and physisorption . The collector chemical molecules have a non-polar part and a polar part. The polar parts of the collector molecules adsorb to the surface areas of ore particles having the valuable minerals. The non-polar parts are hydrophobic and are thus re- pelled from water. The repelling causes the hydropho ^¬ bic tails of the collector molecules to adhere to flo ^¬ tation gas bubbles. Low pressure air supplied by means of an external air blower is directed to a rotor in the flotation through a hollow driveshaft. A suffi- cient amount of adsorbed collector molecules on suffi ^¬ ciently large valuable mineral surface areas on an ore particle will cause the ore particle to become at ^¬ tached to a flotation gas bubble. The flotation gas bubbles rise to the surface of the flotation cell and form a froth layer. In addition to collector chemicals, the flotation chemicals may also comprise froth- ers, modifiers, activators, depressants and extenders. Frothers are used to improve and stabilize froth for ^¬ mation. Modifiers include chemicals that may be used to alter the pH of the slurry. Activators are used to enable collector molecules to adsorb to valuable min ^¬ eral surface areas on ore particles. The activators adsorb first to the valuable mineral surface areas on ore particles and form a layer or a thin film of acti- vator molecules upon the valuable mineral surface are ^¬ as. The collector molecules will adsorb on the layer or thin film of activator. Depressant molecules are used to improve selectivity of collector molecules by preventing collector molecules to adsorb to surface areas on ore particles having an undesirable mineral. Thereby the likelihood of ore particles having large surface areas of an undesirable mineral to attach to flotation gas bubbles is reduced.

The froth flotation is performed in several flotation cells in series. The ore particles that have not been collected in the froth during the flotation process are called tailings. The tailings and froth are usually processed in different subsequent flota ^¬ tion cells.

A problem with flotation processes in prior art is that excessive concentration of at least one collector chemical degrades the quality of flotation products meaning that the concentration of a valuable mineral may not be high enough due to excess gangue present in the flotation product. On the other hand, if the collector chemical dosage is too low, the re- covery of the valuable mineral is low.

An excessive use of at least one collector chemical or other flotation chemicals is also an eco ^¬ logical and economical factor. SUMMARY OF THE INVENTION:

According to one aspect of the invention, the invention is method for automatic control of concen ^¬ tration of at least one collector chemical or other flotation chemicals in a froth flotation process in a froth flotation system comprising a plurality of flotation cells, the method comprising: determining, by at least one flotation control computer, a rate of in ^¬ troduction of ore particles into the flotation system and an average metal content mass percentage in the ore particles; controlling, by the at least one flota ^¬ tion control computer, at least one electronically controlled valve to let at least one respective flow of at least one collector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one flow conforming to an ini ^¬ tial flow rate; extracting, by at least one primary sampling device, a respective at least one first slur ^¬ ry sample from a respective at least one sampling point in the froth flotation system, the at least one sampling point being arranged to receive slurry from a respective at least one flotation cell outlet or flo- tation cell inlet, the extracting of the at least one first slurry sample following the determining the rate of the introduction of the ore particles into the flo ^¬ tation system; extracting, by a secondary sampling device, at least one second slurry sample from the at least one first slurry sample; removing, by a filter ^¬ ing apparatus, ore particles from the at least one second slurry sample to obtain a solids free sample; introducing, by the filtering apparatus, the solids free sample to an analysis device; determining, using the analysis device, a concentration of the at least one collector chemical or other flotation chemicals, or a concentration of at least one respective decompo ^¬ sition product of the at least one collector chemical or other flotation chemicals from the solids free sam- pie; computing, by the at least one flotation control computer, a difference between the concentration determined and a target concentration; determining, by the at least one flotation control computer, an updat ^¬ ed flow rate of introduction of the at least one col- lector chemical or other flotation chemicals into the flotation system, the rate being computed based on at least the difference computed and the rate of intro ^¬ duction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles; and controlling, by the at least one flotation control computer, the at least one electronically controlled valve to let the at least one re- spective flow of the at least one collector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one flow conforming to the updated flow rate.

According to another aspect of the invention, the invention is a method for automatic control of concentration of at least one collector chemical in a froth flotation process in a froth flotation system comprising a plurality of flotation cells, the method comprising: determining, by at least one flotation control computer, a rate of introduction of ore parti ^¬ cles into the flotation system and an average metal content mass percentage in the ore particles; control ^¬ ling, by at least one flotation control computer, at least one electronically controlled valve to let at least one respective flow of at least one collector chemical into the flotation system, the sum of flow rates of the at least one flow conforming to an ini ^¬ tial flow rate; extracting, by a primary sampling de- vice, a first slurry sample from a sampling point in the froth flotation system, the sampling point being arranged to receive slurry from a flotation cell out ^¬ let or flotation cell inlet, the extracting of the first slurry sample following the determining the rate of the introduction of the ore particles into the flo ^¬ tation system; extracting, by a secondary sampling device, at least one second slurry sample from the first slurry sample; removing, by a filtering apparatus, ore particles from the at least one second slurry sample to obtain a solids free sample; introducing, by the filtering apparatus, the solids free sample to an analysis device; determining, using the analysis de ^¬ vice, a concentration of the at least one collector chemical or a concentration of at least one respective decomposition product of the at least one collector chemical from the solids free sample; computing, by the at least one flotation control computer, a differ- ence between the concentration determined and a target concentration; determining, by the at least one flotation control computer, an updated flow rate of intro ^¬ duction of the at least one collector chemical into the flotation system, the rate being computed based on at least the difference computed and the rate of in ^¬ troduction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles; and controlling, by the at least one flotation control computer, the at least one elec ^¬ tronically controlled valve to let the at least one respective flow of the at least one collector chemical into the flotation system, the sum of flow rates of the at least one flow conforming to the updated flow rate.

According to another aspect of the invention, the invention is a froth flotation system comprising: a plurality of froth flotation cells; at least one electronically controlled valve arranged to let at least one respective flow of at least one collector chemical or other flotation chemicals into the flota ^¬ tion system, the sum of flow rates of the at least one respective flow conforming to an initial flow rate, and arranged to let the at least one respective flow of at least one collector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one respective flow conforming to an updated flow rate; at least one primary sampling device arranged to extract a respective at least one first slurry sample from a respective at least one sampling point in the froth flotation system, the at least one sampling point being arranged to receive slurry from a respective at least one flotation cell outlet or inlet , the extracting of the at least one first slurry sample following a determining of a rate of the introduction of the ore particles into the flo ^¬ tation system and an average metal content mass per- centage in the ore particles; a second sampling device arranged to extract at least one second slurry sample from one or more of the at least one first slurry sam ^¬ ples; a filtering apparatus arranged to remove ore particles from the at least one second slurry sample to obtain a solids free sample, to introduce the sol ^¬ ids free sample to an analysis device; the analysis device arranged to determine a concentration of the at least one collector chemical or other flotation chemi- cals, or a concentration of at least one respective decomposition product of the at least one collector chemical or other flotation chemicals from the solids free sample and to transmit information on the concen ^¬ tration to at least one flotation control computer; the at least one flotation control computer communica ^¬ tively connected to the at least one electronically controlled valve and the analysis device; and wherein the at least one flotation control computer controls the at least one electronically controlled valve, de- termines a rate of introduction of ore particles into the flotation system and an average metal content mass percentage in the ore particles, computes a difference between the concentration determined by the analysis device and a target concentration, determines an up- dated flow rate of the at least one collector chemical or other flotation chemicals into the flotation system, the updated flow rate being computed based on at least the difference computed and the rate of intro ^¬ duction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles, and controls the at least one electron ^¬ ically controlled valve to let the at least one re ^¬ spective flow of the at least one collector chemical or other flotation chemicals into the flotation sys- tern, the sum of flow rates of the at least one flow conforming to the updated flow rate. According to another aspect of the invention, the invention is a froth flotation control computer comprising at least one processor and a memory storing instructions that, when executed, cause the apparatus to determine a rate of introduction of ore particles into the flotation system and an average metal content mass percentage in the ore particles, to control at least one electronically controlled valve to let at least one flow of at least one collector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one flow con ^¬ forming to an initial flow rate, to transmit at least one first signal to at least one primary sampling de ^¬ vice to cause the at least one primary sampling device to extract a respective at least one first slurry sam ^¬ ple from a respective at least one sampling point in the froth flotation system, the at least one sampling point being arranged to receive slurry from a respec ^¬ tive at least one flotation cell outlet or flotation cell inlet, the extracting of the at least one first slurry sample following the determining the rate of the introduction of the ore particles into the flota ^¬ tion system, to transmit at least one second signal to a secondary sampling device to cause the secondary sampling device to extract at least one second slurry sample from one or more of the at least one first slurry sample, to transmit at least one third signal to a filtering apparatus to cause the filtering appa ^¬ ratus to remove ore particles from the at least one second slurry sample to obtain a solids free sample, to transmit at least one fourth signal to the filter ^¬ ing apparatus or to the analysis device to cause the filtering apparatus or the analysis device to intro ^¬ duce the solids free sample to the analysis device, to transmit at least one fifth signal to cause the analy ^¬ sis device to determine a concentration of the at least one collector chemical or other flotation chemi- cals, or a concentration of at least one respective decomposition product of the at least one collector chemical or flotation chemicals from the solids free sample, to compute a difference between the concentra- tion determined and a target concentration, to determine an updated flow rate of introduction of the at least one collector chemical or other flotation chemicals into the flotation system, the rate being comput ^¬ ed based on at least the difference computed and the rate of introduction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles, and to control the at least one electronically controlled valve to let the at least one respective flow of the at least one col- lector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one flow conforming to the updated flow rate.

According to another aspect of the invention, the invention is a method for automatic control of at least one collector chemical or other flotation chemicals in a froth flotation process in a froth flotation system. In the method there is determined a rate of introduction of ore tonnages into the flotation sys ^¬ tem. An initial flow rate of at least one collector chemical or other flotation chemicals is provided to the flotation system based on the ore feed rate (t/h) or metal content in the feed (wt%) . Slurry samples are extracted from tailings from at least one flotation cell in a series of flotation cells in the flotation system and/or flotation feed with recycled process water. The slurry samples are filtered and a resulting liquid sample is analyzed, for example, using a capil ^¬ lary electrophoresis device, to determine a concentra ^¬ tion of the at least one collector chemical or other flotation chemicals. The residual concentration is utilized for determining an updated flow rate of the at least one collector chemical or other flotation chemicals to the flotation system.

In one embodiment of the invention, the meth ^¬ od further comprises transmitting information to the at least one flotation control computer on a sampling point in the froth flotation system from which the at least one second slurry sample is extracted; and se ^¬ lecting the target concentration based on the information on the sampling point.

In one embodiment of the invention, the meth ^¬ od further comprises feeding the one or more first samples from the at least one primary sampling device to the secondary sampling device.

In one embodiment of the invention, the at least one flotation cell outlet comprises at least one of a tailings outlet of a rougher flotation cell, a tailings outlet of a scavenger flotation cell and a froth outlet of a cleaning flotation cell.

In one embodiment of the invention, the ex- tracting of the at least one first slurry samples fol ^¬ lows the determining of the rate of introduction of the ore particles into the flotation system and the determining of average metal content mass percentage in the ore particles after at least a predefined time.

In one embodiment of the invention, the pre ^¬ defined time corresponds to a time required for the rate of introduction of the ore particles into the flotation system to have an effect on the concentra ^¬ tion of the at least one collector chemical or other flotation chemicals at the plurality of sampling points in the froth flotation system.

In one embodiment of the invention, the step of removing ore particles from the at least one second slurry sample to obtain the solids free sample method further comprises: pumping the at least one second slurry sample to a settling tank comprised in the filtering apparatus; allowing slurry to settle a prede- fined time in the settling tank in order to subside at least part of the ore particles; pumping a settled slurry obtained by the settling from the settling tank through a filter to a sample tub of the filtering ap- paratus from which a solution obtained from the set ^¬ tled liquid through the filtering is pumped to a sam ^¬ ple vial of the analysis device.

In one embodiment of the invention, the meth ^¬ od further comprises extracting, by a conditioner sam- pling device, a conditioner slurry sample from the flow of slurry from a conditioner tank into the rougher flotation cell; and providing the conditioner slurry sample to secondary sampling device as part of the plurality of first slurry samples.

In one embodiment of the invention, the meth ^¬ od further comprises extracting, by a recycled process water sampling device, a recycled process water sample from a feed of recycled process water into the flota ^¬ tion system; and providing the recycled process water sample to the secondary sampling device as part of the plurality of first slurry samples or as the solids free sample to the analysis device.

In one embodiment of the invention, the at least one collector chemical comprises a Thiol collec- tor.

In one embodiment of the invention, the Thiol collector comprises at least one of Xanthate, Dithio- phosphate and Dithiophosphinate .

In one embodiment of the invention, the other flotation chemicals comprise frothers, modifiers, ac ^¬ tivators, depressants or extenders.

In one embodiment of the invention, the at least one primary sampling device comprises at least one of a linear sampler comprising a sample cutter, a suction pipe sampler and a pressure pipe sampler. In one embodiment of the invention, the at least one primary sampling device comprises a proba ^¬ bilistic sampler.

In one embodiment of the invention, the ore particles are introduced into a conditioner tank, the conditioner tank storing a mixture of ore particles and water, the conditioner tank providing a flow of slurry into a rougher flotation cell, the rougher flotation cell being among the plurality of flotation cells.

In one embodiment of the invention, the flow of the at least one collector chemical or other flota ^¬ tion chemicals conforming to the initial flow rate or the updated flow rate is let into the conditioner tank.

In one embodiment of the invention, the flow of the at least one collector chemical or other flota ^¬ tion chemicals conforming to the initial flow rate or the updated flow rate is let into at least one of one or more flotation cells among the plurality of flota ^¬ tion cells, a conditioner tank, and a grinding mill.

In one embodiment of the invention, the anal ^¬ ysis device is a capillary electrophoresis device.

In one embodiment of the invention, each of the at least one electronically controlled valve, which let the flow of at least one collector chemical or other flotation chemicals into the flotation system, let a portion or a sub-flow of the flow into the flotation system. The portion or the sub-flow may be provided to different points in the flotation system such as a conditioner tank or a flotation cell.

In one embodiment of the invention, the rate of introduction of ore particles is measured in ore tonnages per hour.

In one embodiment of the invention, the in ^¬ troduction of ore particles may also be referred to as ore feed. In one embodiment of the invention, the aver ^¬ age metal content mass percentage in the ore particles is entered manually into the at least one flotation control computer by a user. The metal content mass percentage may be determined using a chemical analysis performed on a sample from an ore or a specific batch or load of ore.

In one embodiment of the invention, the aver ^¬ age metal content mass percentage in the ore particles is determined using a second analysis device based on a sample collected automatically at predefined inter ^¬ vals from the ore particles introduced into the flota ^¬ tion system. The second analysis device may be a mag ^¬ netic sensor.

In one embodiment of the invention, the at least one sampling point is arranged to receive slurry from the respective at least one flotation cell outlet or flotation cell inlet pipe so that the at least one primary sampling device is installed in the respective at least one flotation cell outlet or flotation cell inlet. A primary sampling device may also be installed to a flotation cell outlet pipe or inlet pipe.

In one embodiment of the invention, the at least one primary sampling device comprises a proba- bilistic sampler, the purpose of which is to extract a sample that is representative of the flow of slurry and to ensure that any particle in the slurry flowing through the sampling device has an equal probability of being selected. A probabilistic sampler may com- prise a hollow sleeve with an inlet portion for connecting to an incoming pipe and with an outlet portion for connecting to an outgoing pipe. Following the inlet portion there may be a turbulence introducing sec ^¬ tion in the hollow sleeve which is followed by a sam- pie extracting portion, for example, a horizontal or vertical sample cutter. The sample cutter has blades between which the sample is received. The sample cut- ter leads slurry to a pipe branching from the sampling device hollow body. The branching pipe may be lead to the second sampling device.

The embodiments of the invention described hereinbefore may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the invention. A method, a flotation system or a flotation control computer to which the invention is related may comprise at least one of the embodiments of the inven ^¬ tion described hereinbefore.

It is to be understood that any of the above embodiments or modifications can be applied singly or in combination to the respective aspects to which they refer, unless they are explicitly stated as excluding alternatives .

The benefits of the present invention relate to improved diminished wasting of at least one collec ^¬ tor chemical or other flotation chemicals and improved performance of the flotation system, for example, in improved concentrate quality and improved recovery of concentrate .

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illus ^¬ trate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:

Fig. 1 illustrates a froth flotation cell ac ^¬ cording to an embodiment of the invention;

Fig. 2A illustrates a froth flotation system according to an embodiment of the invention where one primary sampling device is employed; Fig. 2B illustrates a froth flotation system according to an embodiment of the invention where a plurality of primary sampling devices is employed;

Fig. 2C illustrates a froth flotation system with multiple feeds of the at least one collector chemical into the froth flotation system in one embod ^¬ iment of the invention;

Fig. 3 illustrates a filtering apparatus in one embodiment of the invention;

Fig. 4 illustrates an electrophoresis device in one embodiment of the invention; and

Fig. 5 illustrates flow chart illustrating a method for automatic dosing at least one collector chemical to a froth flotation process in a froth flo- tation system a rotor-stator assembly in one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Figure 1 illustrates a froth flotation cell according to an embodiment of the invention.

In Figure 1 there is a froth flotation cell, in short, a flotation cell 100. The flotation cell comprises a tank 102, which may also be referred to as a container 102. Tank 102 comprises an influent feed inlet 104 for slurry 130. Tank 102 comprises an outlet 106 for removal of tailings. The feed inlet 104 and the removal outlet 106 may be arranged to a sidewall of tank 102. Feed inlet 104 may be at a height below or equal to a level of an upper plate of a stator 112 mounted in tank 102. Removal outlet 106 may be ar ^¬ ranged at the level of the bottom of tank 102 or at a height below the level of the upper plate of stator 112. Stator 112 is mounted on the bottom of flotation cell 102 on a plurality of supports, for example, sup- port legs such as support leg 114. Stator 112 has a plurality of blades (not shown) arranged to aid in bubble formation and aeration of slurry 130. To an inner space defined by the stator blades is mounted a rotor 110 which is suspended from a hollow axis 120. The hollow axis 120 rotates the rotor 110 and receives from an air inlet 122 a flow of flotation gas such as atmosphere air. The flow of flotation gas exits from the hollow axis 120 inside rotor 110. In one embodi- ment of the invention, rotor 110 comprises an array of rotor blades and openings (not shown) via which flota ^¬ tion gas exits rotor 110 as a plurality of flows. In one embodiment of the invention, stator blades in sta ^¬ tor 112 subdue swirling flow produced by rotor 110 thereby forming bubble jet flows in radial direction away from stator 100 and toward the wall of the flota ^¬ tion cell 102, which may create favorable conditions for air bubble dispersion and mixing. Flotation cell receives a flow of suspension, that is, a flow of slurry 130 comprising ore particles such as ore parti ^¬ cle 132, water, at least one collector chemical and possible non-collector flotation reagents. The collec ^¬ tor chemical molecules adhere to surface areas on ore particles having the valuable mineral, for example, ore particle 132, through an adsorption process. The valuable mineral acts as the adsorbent while the col ^¬ lector chemical acts as the adsorbate. The collector chemical molecules form a film on the valuable mineral areas on the surface of the ore particle. The adsorp- tion may be based on, for example, coupled electro ^¬ chemical and chemical reactions, catalytic oxidation, metathetical substitution, chemisorpt ion, physisorp- tion, or a combination of chemisorpt ion and physisorp- tion. The collector chemical molecules have a non- polar part and a polar part. The polar parts of the collector molecules adsorb to the surface areas of ore particles having the valuable minerals. The non-polar parts are hydrophobic and are thus repelled from wa ^¬ ter. The repelling causes the hydrophobic tails of the collector molecules to adhere to flotation gas bub ^¬ bles. An example of a flotation gas is atmosphere air pumped to flotation cell 102. A sufficient amount of adsorbed collector molecules on sufficiently large valuable mineral surface areas on an ore particle may cause the ore particle to become attached to a flota ^¬ tion gas bubble. An ore particle 134 attached to a gas bubble 142 is illustrated in Figure 1. The flotation gas bubbles such as bubbles 142 and 144 rise to the surface of the flotation cell and form a layer of froth 150. Froth 150 gathered to a surface of slurry in flotation cell 102 is let to flow out of flotation cell 102 via a launder lip 152. Tailings are arranged to flow via removal outlet 106 either by pumping or by gravity to a tailings box or a subsequent flotation cell (not shown) .

The non-collector flotation chemicals may comprise frothers, modifiers, activators, depressants and extenders. Frothers are used to improve and stabi ^¬ lize froth formation. Modifiers include chemicals that may be used to alter the pH of the slurry. Activator molecules are used to enable collector molecules to adsorb to valuable mineral surface areas on ore parti ^¬ cles. The activator molecules adsorb first to the val ^¬ uable mineral surface areas on ore particles and form a layer or a thin film of activator molecules upon the valuable mineral surface areas. The collector mole- cules may adsorb as a further adsorbate layer on the layer or thin film of activator molecules. The activator molecules act as an adsorbent for the collector molecules. Depressant molecules are used to improve selectivity of collector molecules by preventing col- lector molecules to adsorb to surface areas on ore particles having an undesirable mineral. Thereby the likelihood of ore particles having large surface areas of an undesirable mineral to attach to flotation gas bubbles is reduced. Figures 2A and 2B illustrate a froth flotation process in a froth flotation system according to an embodiment of the invention. A froth flotation system 200 illustrated in Figure 2A compris ^¬ es a conditioner tank 203. To conditioner tank 203 is provided a flow of at least one collector chemical or other flotation chemicals 201 through a valve 290 which ensures that the flow conforms to a specific in- itial flow rate. In one embodiment of the invention, at least one of the at least one collector chemical or other flotation chemicals is dissolved first into a solution, for example, from a pellet or a block to an aqueous liquid with a high concentration of the col- lector chemical dissolved from the pellet. To condi ^¬ tioner tank 203 is also provided a feed of ore parti ^¬ cles 202 from a storage of ground ore 202B. The feed of ore particles 202 may be measured, for example, in metric tons per hour. The feed of ore particles con- forms to a specific feed rate at which particles are introduced to conditioner tank 203. The feed of ore particles may be referred as a flow of ore particles if the particles are suspended in water. Conditioner tank 203 may be sized so that it allows ore particles, water and collector chemicals or other chemicals time to be mixed. In conditioning tank 203 collector chemicals start adsorbing on surface areas containing valu ^¬ able minerals on ore particles.

Froth flotation system 200 comprises a plu- rality of flotation cell banks which represent differ ^¬ ent stages in the flotation process. There is a rough ^¬ er flotation cell bank 230, a scavenger flotation cell bank 240, a first cleaning flotation cell bank 250 and a second cleaning flotation cell bank 255. The second cleaning flotation cell bank is illustrated to have a single flotation cell, but may comprise a plurality of flotation cells in series. In each flotation cell bank the flotation cells are connected in a series in which slurry received from conditioning tank 203 or from another flotation cell bank is first led to a first flo ^¬ tation cell in the bank in question. The froth formed through flotation in the first flotation cell is collected in a launder at a surface of the first flota ^¬ tion cell from which the froth is allowed to flow or is pumped to another flotation cell bank. The froth formed is referred to as concentrate. A flow of tail- ings from the first flotation cell is allowed to flow to a second flotation cell in the bank in question.

In Figures 2A and 2B a flotation cell 232 in rougher flotation cell bank 230 receives a flow of slurry from conditioner tank 203 as illustrated with arrow 204. Slurry is processed by flotation cell 232 producing froth with valuable mineral containing particles attached to bubbles produced by the airflow from a rotor and a stator of flotation cell 232 as explained in association with Figure 1. The froth is collected to a launder 205 of flotation cell 232 from which the froth is allowed to flow or is pumped to a regrinding ball mill as illustrated with arrows 206, 207 and 212. A flow of tailings slurry from flotation cell 232 is allowed to flow or is pumped to flotation cell 234 via a pipe 208 connecting flotation cell 232 to flotation cell 234. Slurry is processed by flota ^¬ tion cell 234 producing froth with valuable mineral containing particles attached to bubbles. The froth from flotation cell 234 is allowed to flow through a launder of flotation cell 234 to the regrinding ball mill as illustrated with arrows 209 and 212. A flow of tailings slurry from flotation cell 234 is allowed to flow or is pumped to flotation cell 236 via a pipe 210 connecting flotation cell 234 to flotation cell 236. Slurry is processed by flotation cell 236 producing froth with valuable mineral containing particles at ^¬ tached to bubbles. The froth from flotation cell 236 is allowed to flow through a launder of flotation cell 236 to the regrinding ball mill as illustrated with arrows 211 and 212. A flow of tailings from flotation cell 236 is allowed to flow or is pumped to scavenger flotation cell bank 240 and therein to flotation cell 242 as slurry. Froth produced by flotation in flotation cells 242 and 244 is allowed to flow or is pumped to the regrinding ball mill as illustrated with arrows 245, 246 and 247. Tailings that flow from flotation cell 246 to a tailings box are illustrated with arrow 248.

Reground slurry from regrinding ball mill 213 is allowed to flow or is pumped to first cleaning flo ^¬ tation cell bank 250. The reground slurry is fed to a flotation cell 252 within first cleaning flotation cell bank 250. Flotation process takes place in flota ^¬ tion cells 252 and 254. Froth produced by flotation in flotation cells 252 and 254 is allowed to flow or is pumped as slurry to the second cleaning flotation cell bank 255 as illustrated with arrows 216, 217 and 218. Tailings that flow from flotation cell 246 to a tail ^¬ ings box of flotation cell 254 are allowed to flow or are pumped to regrinding ball mill 213 as illustrated with arrow 258.

The slurry from first cleaning flotation cell bank 250 is fed to cleaning flotation cell 256 within second cleaning flotation cell bank 255. Flotation process takes place in flotation cell 256. Froth pro ^¬ duced by flotation in flotation cells 252 and 254 is allowed to flow or is pumped as concentrate to a fur ^¬ ther processing stage, for example, concentrate leach ^¬ ing. Tailings that flow from flotation cell 256 to a tailings box of flotation cell 256 are allowed to flow or are pumped back to first cleaning flotation cell bank 250 and therein to flotation cell 252, as illustrated with arrow 257. In Figure 2A there is shown a primary sampling point in the froth flotation process carried out in froth flotation system 200. There is a primary sampling point 260 installed to a pipeline (not shown) feeding slurry from conditioning tank 203 to flotation cell 232 within rougher flotation cell bank 230.

In the primary sampling point 260 there is a respective primary sampling device (not shown) . The primary sampling device may be probabilistic sampling device which is arranged to extract representative samples of slurry so that any portion of slurry has equal probability of becoming sampled. The primary sampling device at the respective sampling point 260, is connected with a respective pipeline illustrated as respective arrow 270 to a secondary sampling device 280. The secondary sampling device may be, for example, a multiplexer.

The primary sampling device 260 is arranged to extract a first slurry sample which is fed to sec- ondary sampling device 280 via a separate pipeline.

In Figure 2B there is shown a plurality of primary sampling points in the froth flotation process carried out in froth flotation system 200. There is a primary sampling point 260 installed to a pipeline (not shown) feeding slurry from conditioning tank 203 to flotation cell 232 within rougher flotation cell bank 230. There is also a primary sampling point 261 in a pipeline (not shown) feeding tailings as slurry from flotation cell 236 within rougher flotation cell bank 230 to flotation cell 242 within scavenger flotation cell bank 240. There is also a primary sampling point 262 in a tailings box of flotation cell 244 that receives tailings from flotation cell 244. There is also a primary sampling point 263 in a pipeline (not shown) feeding concentrate as slurry from flotation cells 252 and 254 within first cleaning flotation cell bank 250 to flotation cell 256 within second cleaning flotation cell bank 256. There is also a primary sampling point 264 before conditioning tank 203. Primary sampling point 264 extracts samples from a feed of ore particles introduced into conditioner tank 203.

In the plurality of primary sampling points

260, 261, 262, 263 and 264 there is a respective plu ^¬ rality of primary sampling devices (not shown) . The primary sampling devices may be probabilistic sampling devices which are arranged to extract representative samples of slurry so that any portion of slurry has equal probability of becoming sampled. The plurality of primary sampling devices at the respective plurali ^¬ ty of sampling points 260, 261, 262, 263 and 264 are connected with a plurality of respective pipelines il- lustrated as respective arrows 270, 271, 272, 273 and 274 to a secondary sampling device 280. The secondary sampling device may be, for example, a multiplexer.

The plurality of primary sampling devices are arranged to extract a respective plurality of first slurry samples which are fed to secondary sampling device 280 via separate pipelines.

Secondary sampling device 280 shown in Figures 2A and 2B is arranged to extract a second slurry sample from one of the at least one first slurry sam- pies. Secondary sampling device 280 pumps the extract ^¬ ed second slurry sample to a feed box 281 in associa ^¬ tion with a filtering apparatus 282. The filtering apparatus is arranged to remove ore particles from the second sample to obtain a solids sample suitable for capillary electrophoresis. The filtering apparatus in ^¬ troduces the solids free sample to a capillary elec ^¬ trophoresis device 283 after the removing of the ore particles .

The starting point in Figures 2A and 2B for extracting a slurry sample or slurry samples is that, for example, in response to a control signal (not shown) from at least one flotation control computer 285, one primary sampling device belonging to the at least one primary sampling device extracts a first slurry sample. The extracting may also be performed by a human operator which operates the primary sampling device to extract the first slurry sample. The slurry sample extracted flows due to gravitation or is pumped using a pump, for example, controlled by flotation control computer 285, to a sample pipe (not shown) in second sampling device 280.

In one embodiment of the invention, second sampling device 280 comprises a plurality of sample pipes each of which may be arranged to receive slurry samples from a specific primary sampling device. Thus, slurry samples from different primary sampling devices may not be mixed in secondary sampling device 280. In response to a control signal from at least one flota ^¬ tion control computer 285 or in response to a command entered by a human operator using a user interface of secondary sampling device 280, secondary sampling de- vice 280 extracts a second slurry sample from the first slurry sample. Thereupon, secondary sampling device 280 pumps the extracted second slurry sample to the feed box 281 in association with filtering apparatus 282, for example, in response to a control sig- nal from flotation control computer 285. Flotation control computer 285 may transmit a control signal to a control unit (not shown) within filtering apparatus 282. In response to the control signal, filtering ap ^¬ paratus 282 starts a settling and filtration sequence for the second slurry sample from the feed box 281 un ^¬ der control of the control unit within filtering appa ^¬ ratus 282. After the settling phase is complete, the control unit within filtering apparatus 282 controls a pump to feed the settled second slurry sample through a filter and introduces the filtered solution to a sample tub of capillary electrophoresis device 283. Thereupon, for example, in response to a control sig- nal from at least one flotation control computer 285 or a control signal from the control unit within fil ^¬ tering apparatus 282, capillary electrophoresis device 283 determines a concentration of the at least one collector chemical or other flotation chemicals in the liquid sample. The concentration of the at least one collector chemical or other flotation chemicals may be a total concentration of at least two collector chemicals or other flotation chemicals in cases where at least two collector chemicals or other flotation chemicals are used. Alternatively, capillary electrophore ^¬ sis device 283 is arranged to determine a concentra ^¬ tion of at least one respective decomposition product of the at least one collector chemical or other flota- tion chemicals. The information on the concentration determined regarding the at least one collector chemical or other flotation chemicals, or the at least one respective decomposition product of the at least one collector chemical or other flotation chemicals is transmitted from capillary electrophoresis device 283 to at least one flotation control computer 285.

The at least one flotation control computer 285 computes a difference between the concentration determined and a target concentration for the chemical or a plurality of chemicals, the concentration of which was determined by capillary electrophoresis de ^¬ vice 283. The concentration determined and the target concentration may be a total concentration of at least two different collector chemicals or other flotation chemicals, or decomposition products of at least one collector chemical or other flotation chemicals. Thereupon, the at least one flotation control computer 285 determines an updated flow rate of the at least one collector chemical or other flotation chemicals into conditioner tank 203, the updated flow rate being determined based on at least the difference computed between the concentration determined and the target concentration, and the rate of introduction of the ore particles into conditioner tank 203.

In one embodiment of the invention, the up ^¬ dated flow rate is also determined based on the aver- age metal content mass percentage in the ore parti ^¬ cles. The average metal content mass percentage in the ore particles may be determined using a separate anal ^¬ ysis device for a current batch of ore being fed into the flotation system and entered manually using a user interface of flotation control computer 285.

In one embodiment of the invention, an in ^¬ crease or decrease in the flow rate of the at least one collector chemical or other flotation chemicals is adapted by at least one flotation control computer 285 to the rate of introduction of the ore particles into conditioner tank 203. Thereupon, the at least one flotation control computer 285 controls at least one electronically controlled valve to let a flow of the at least one collector chemical or other flotation chemicals into conditioner tank 203 conforming to the updated flow rate of the at least one collector chemi ^¬ cal or other flotation chemicals.

In one embodiment of the invention, the flow of at least one collector chemical or other flotation chemicals 201 into flotation system 200 conforming to the specific initial flow rate or the updated flow rate is provided, in addition to valve 290, through at least one another valve. The at least one another valve may provide a portion of the flow of at least one collector chemical or other flotation chemicals 201 to at least one second point in the flotation pro ^¬ cess. Thus, in one embodiment of the invention, the flow of the at least one collector chemical or other flotation chemicals 201 into flotation system 200 con- sists of at least two sub-flows into at least two dif ^¬ ferent points in the flotation system. Examples of the at least two second points comprise a collector chemical or other flotation chemicals receiving flotation cell, regrinding mill 213, a grinding mill providing the feed of ore particles 202 into conditioner tank 203 or a pump well. The collec ^¬ tor chemical or other flotation chemicals receiving flotation cell may be, for example, one of the flota ^¬ tion cells in rougher flotation cell bank 230, a scavenger flotation cell bank 240, a first cleaning flota- tion cell bank 250 or a second cleaning flotation cell bank 255.

Figure 2C illustrates a froth flotation sys ^¬ tem with multiple feeds of the at least one collector chemical or other flotation chemicals into the froth flotation system in one embodiment of the invention.

In Figure 2C there is illustrated a froth flotation system 200B which is a variation of froth flotation system 200 illustrated in Figures 2A and 2B.

In froth flotation system 200B at least one flow of the at least one collector chemical or other flotation chemicals 201 is fed into flotation system 200, the sum of flow rates of the at least one flow conforming to the specific initial flow rate or the updated flow rate. The at least one flow is provided through at least one respective electronically con ^¬ trolled valve. In Figure 2B three flows, namely, flows 201A, 201B and 201C are fed into flotation system 200 via respective three electronically controlled valves 290A, 290B and 290C controlled by flotation control computer 285. Alternatively, flows 201A, 201B and 201C could be described as flow portions or sub-flows of flow 201 of the at least one collector chemical or other flotation chemicals. Each of these flow portions or sub-flows are let or fed into flotation system 200 via respective electronically controlled valves 290A, 290B and 290C. In Figure 2C there is shown a plurality of flotation cells 2000 comprising at least flotation cells 2010, 2020 and 2030. The plurality of flotation cells may comprise the flotation cells illustrated in Figures 2A and 2B. In Figure 2C there is shown a grinding mill 2100 which may receive a flow of slurry from at least one first flotation cell of plurality of flotation cells 2000 and may provide a ground flow of slurry back to at least one second flotation cell of plurality of flotation cells 2000. In Figure 2C flota ^¬ tion control computer 205 which may comprise a plural- ity of computer units or processors controls electron ^¬ ically controlled valves 290A, 290B and 290C based on the specific initial flow rate or the updated flow rate determined by flotation control computer 205.

Flotation control computer 285 determines a rate of introduction of ore particles into flotation system 200B and an average metal content mass percent ^¬ age in the ore particles. Flotation control computer 285 controls the at least one electronically con ^¬ trolled valve 290A, 290B and 290C to let at least one respective flow 201A, 201B and 201C of the at least one collector chemical or other flotation chemicals into the flotation system, the sum of flow rates of the at least one flow conforming to an initial flow rate. Flotation control computer 285 computes a dif- ference between the concentration determined and a target concentration. Flotation control computer 285 determines an updated flow rate of introduction of the at least one collector chemical or other flotation chemicals into the flotation system, the rate being computed based on at least the difference computed and the rate of introduction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles. Flotation control computer 285 controls the at least one electronically controlled valve 290A, 290B and 290C to let the at least one respective flow 201A, 201B and 201C of the at least one collector chemical or other flotation chemicals into flotation system 200B, the sum of flow rates of the at least one flow conforming to the up ^¬ dated flow rate.

In one embodiment of the invention, the at least one respective flow consists of same mixture of at least one collector chemical or other flotation chemicals .

Figure 3 illustrates a filtering apparatus 300, in one embodiment of the invention. Filtering ap- paratus 300 corresponds to filtering apparatus 282 in Figures 2A and 2B. Filtering apparatus 300 comprises a control unit 330 which controls a plurality of elec ^¬ tronically controlled pumps and electronically con ^¬ trolled valves. Control unit 330 is communicative con- nected to electronically controlled pump 303 via com ^¬ munication channel 331, electronically controlled valve 352 via communication channel 332, electronical ^¬ ly controlled valves 353 and 354 via communication channel 334, electronically controlled pump 308 via communication channel 333, and electronically con ^¬ trolled valve 351 via communication channel 335. In Figure 3 there is also illustrated capillary electro ^¬ phoresis device 313. Capillary electrophoresis device controls electronically controlled pump 314 via commu- nication channel 341 and electronically controlled pump 311 via communication channel 342.

The filtering apparatus comprises a feed box 302 which is a tank or a basin. Feed box receives a slurry sample via an inlet pipe 301 in a sidewall of feed box 302. The slurry sample is received from sec ^¬ ondary sampling device 280 illustrated in Figures 2A, 2B and 2C. The other end of inlet pipe 301, which is not shown in Figure 3, is connected to secondary sam ^¬ pling device 280. In association with feed box 302 there is electronically controlled pump 303 which is configured to pump a predefined amount of slurry from feed box 302 via pipes 304A and 304B to a settling tank 305. Electronically controlled pump 303 is acti ^¬ vated in response to a control signal from control unit 330 via communication channel 331. The predefined amount of slurry is based on a first predefined time that electronically controlled pump 303 pumps. Elec ^¬ tronically controlled pump 303 may be deactivated not to pump in response to a control signal from control unit 330 via communication channel 331 or in response to an internal timer expiring within electronically controlled pump 303. After a pumping of the predefined amount of slurry to settling tank 305, control unit 330 waits a second predefined time and thereby lets the slurry in settling tank 305 to settle the second predefined time so that at least part of solid ore or gangue particles subside to a bottom of settling tank 305. The at least part of solid ore may be most of the solid ore or gangue particles. The second predefined time may be, for example, between 20 and 30 minutes. After the settling, control unit 330 activates elec- tronically controlled pump 308 by transmitting to electronically controlled pump 308 a control signal via communication channel 333. Electronically con ^¬ trolled pump 308 may be a peristaltic pump. Electroni ^¬ cally controlled pump 308 is kept active a third pre- defined time, which causes electronically controlled pump 308 to pump a predefined amount of settled slurry through a rod filter 306 and via pipe 307 to a sample tub 309 arranged inside a sample basin 316. By settled slurry is meant a slurry sample from which ore parti- cles have subsided during a settling time. Electroni ^¬ cally controlled pump 308 may be deactivated not to pump in response to a control signal from control unit 330 via communication channel 333 or in response to an internal timer expiring within electronically con- trolled pump 308. The rod filter may have a pore size of 5 to 15 micrometers, for example 10 micrometers. The rod filter may be made of steel. Following the pumping of the predefined amount of settled liquid to sample tub 309, control unit 330 transmits a control signal via communication channel 334 to electronically controlled valves 352 and 353 which open in response to the control signal. Electronically controlled valves 352 and 353 are kept open by control unit, for example, 18 seconds, after which electronically controlled valves 352 and 353 are closed, in response to an internal timer or a control signal from control unit 330 via communication channel 334. During the time electronically controlled valves 352 and 353 are kept open, water flows with a constant pressure thereby backwashing pipe 307 and rod filter 306. Simultaneously, water flows to the valve 351 body, making turbulence and getting rid of possible blockages in the bottom of the settling tank 305. The pressure is measured using pressure gauge 361. There ^¬ upon, control unit 330 transmits a control signal via communication channel 334 to electronically controlled valve 354 which opens in response to the control sig ^¬ nal. Electronically controlled valve 354 is kept open by control unit, for example, 24 seconds, after which electronically controlled valve 353 is closed, in re ^¬ sponse to an internal timer or a control signal from control unit 330 via communication channel 334. During the time electronically controlled valve 354 is kept open, pressurized air flows with a constant pressure thereby cleaning pipe 307 and rod filter 306. The pressure is measured using pressure gauge 362. Simul- taneously with opening electronically controlled valve 354, control unit 330 transmits a control signal to electronically controlled valve 351 to open electroni ^¬ cally controlled valve 351. Electronically controlled valve 351 is kept open by control unit 330 the same time that electronically controlled valve 354 is kept open, after which electronically controlled valve 351 is closed, in response to an internal timer or a con- trol signal from control unit 330 via communication channel 335. Keeping electronically controlled valve 351 open allows settling tank to be cleared. Valve 355 may be opened manually to if sample tub 309 needs to be cleared.

Thereupon, capillary electrophoresis device 313 transmits a control signal to electronically con ^¬ trolled pump 311 via communication channel 342 to ac ^¬ tivate electronically controlled pump 311 for the du- ration of a fourth predefined time. During the fourth predefined time, settled liquid from sample tub 309 is pumped to sample vial 312 in capillary electrophoresis device 313. Thereupon, capillary electrophoresis de ^¬ vice 313 determines the concentration of the at least one collector chemical or other flotation chemicals, or the concentration of at least one respective decom ^¬ position product of the at least one collector chemical or other flotation chemicals. Following the determination, capillary electrophoresis device 313 trans- mits a control signal to electronically controlled pump 314 via communication channel 341 to activate electronically controlled pump 314 to pump the ana ^¬ lyzed sample from sample vial 312 to sample basin 316 via pipe 315. Sample liquid in sample basin 316 is al- lowed to overflow from sample basin 316 as illustrated with arrow 317. Similarly, slurry samples in settling basin 305 are allowed to overflow from settling basin 305 as illustrated with arrow 370.

Figure 4 illustrates a capillary electropho- resis device 400 in one embodiment of the invention. Capillary electrophoresis device 400 also comprises a capillary 422 which is, for example, made of fused silica SiC>2. Capillary has a bore diameter between 20 to 250 pm, for example, 49 pm. The length of capillary 422 is, for example, 60 cm and the length from inlet reservoir end to detector window may be, for example, 50 cm. Capillary 422 may be covered with polymer coat- ing to make capillary 422 more robust than a capillary of pure silica. Capillary 422 has a window (not shown) which lacks the polymer coating and which permits absorbing of light or ultraviolet light from a beam of light emitted from a light source 420 by the analyte and passing of unabsorbed light from the light beam to detector 407.

Capillary electrophoresis device 400 compris ^¬ es also a power supply 450 which is arranged to apply a high voltage between 10 and 30 kV across ends of ca ^¬ pillary 422. Power supply has a positive terminal and a lead 454 connected to the positive terminal held at a positive voltage and a negative terminal and a lead 452 connected to the negative terminal held at a nega- tive voltage. Positive lead 452 is electrically con ^¬ nected to an anode suspended in buffer liquid 442 in ^¬ side outlet reservoir 440. Negative lead 452 is elec ^¬ trically connected to a cathode suspended in buffer liquid 432 inside inlet reservoir 430. Power supply from power supply 450 and polarity of power supply 450 is controlled by a computer unit 409 which is communi ^¬ catively connected via communication channel 456 to power supply 450. Computer unit 409 is also communica ^¬ tively connected to a detector 407 which is arranged to receive a beam of light or ultraviolet light from a light source 420. The intensity of the beam received depends on absorbance of an analyte through which the beam of light of ultraviolet passes. Computer unit 409 is arranged to determine concentrations of at least one analyte passing past the window in capillary 422 and more precisely through the beam of light emitted by light source 420 during a capillary electrophoresis analysis process based on a signals received from de ^¬ tector 407 that are indicative of absorbance of light or ultraviolet light of the at least one analyte. Com ^¬ puter unit 409 is communicatively connected to the at least one flotation control computer 285 illustrated in Figure 2A. Computer unit 409 transmits information on the concentration of the at least one collector chemical or other flotation chemicals to the at least one flotation control computer 285 so that the at least one flotation control computer may alter a flow rate of the at least one collector chemical or other flotation chemicals let into conditioner tank 203 illustrated in Figures 2A and 2B.

The starting point for analysis is that sam- pie vial comprises a settled liquid 401 received from sample tub 309 illustrated in Figure 3. Initially ca ^¬ pillary 422 is filled with a background electrolyte called buffer. A sample from a sample vial 420 is in ^¬ troduced to capillary 422 by swapping inlet reservoir side end of capillary 422 from inlet reservoir 430 to sample vial as illustrated with arrow 402. Thereupon, the same end of capillary 422 is swapped back to inlet reservoir, as illustrated with arrow 403. In the case of reverse polarity the sample from sample vial 420 is introduced to the outlet reservoir side end of capil ^¬ lary 422. Due to presence of electrical potential dif ^¬ ference between ends of capillary 422 positively charged ions are attracted to cathode and negative charged ions are attracted to anode. Positively charged ions move towards cathode, whereas negatively charged ions move towards anode. The movement is called electrophoret ic flow. The flow of an analyte originating from sample vial 420 is illustrated with arrows 404, 405 and 406.

The embodiments of the invention described hereinbefore in association with the Figures 1, 2A, 2B, 2C, 3 and 4 presented and the summary of the in ^¬ vention may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the invention. Figure 5 illustrates flow chart illustrating a method for automatic dosing at least one collector chemical or other flotation chemicals to a froth flo ^¬ tation process in a froth flotation system a rotor- stator assembly in one embodiment of the invention.

At step 500 at least one flotation control computer determines a rate of introduction of ore particles into the flotation system, for example, into a conditioner tank, which stores a mixture of ore parti- cles and water. The conditioner tank provides a flow of slurry into a rougher flotation cell.

At step 502 the at least one flotation con ^¬ trol computer controls at least one electronically controlled valve to let a flow of at least one collec- tor chemical or other flotation chemicals conforming to an initial rate into the flotation system.

At step 504 a primary sampling devices extracts a first slurry sample from a sampling point in the froth flotation process. The sampling point may be arranged to receive slurry from flotation cell outlets or inlet pipes.

At step 506 a secondary sampling device ex ^¬ tracts a second slurry sample from the first slurry sample .

At step 508 a filtering apparatus removes ore particles from the at least one second slurry sample to obtain a solids free sample.

At step 510 the filtering apparatus introduc ^¬ es the solids free sample to an analysis device which may be a capillary electrophoresis device.

At step 512 the analysis device determines a concentration of the at least one collector chemical or other flotation chemicals, or a concentration of at least one respective decomposition product of the at least one collector chemical or other flotation chemicals . At step 514 the at least one flotation con ^¬ trol computer computes a difference between the con ^¬ centration determined and a target concentration.

At step 516 the at least one flotation con- trol computer determines an updated rate of introduc ^¬ tion of the at least one collector chemical or other flotation chemicals into the flotation system, the rate being computed based on at least the difference computed and the rate of introduction of the ore par- tides into the flotation system. Thereupon, the at least one flotation control computer controls the at least one electronically controlled valve to let a flow of the at least one collector chemical or other flotation chemicals conforming to the updated rate in- to the flotation system.

Thereupon, the method is finished. The method steps may be executed in the numbering order of the reference numerals above.

The embodiments of the invention described hereinbefore in association with the Figures 1, 2A, 2B, 2C, 3, 4 and 5 presented and the summary of the invention may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the inven- tion.

An example of a method for automatic control of concentration of at least one collector chemical in a froth flotation process in a froth flotation system comprising a plurality of flotation cells comprises: determining, by at least one flotation control comput ^¬ er, a rate of introduction of ore particles into the flotation system and an average metal content mass percentage in the ore particles; controlling, by the at least one flotation control computer, at least one electronically controlled valve to let at least one respective flow of at least one collector chemical in ^¬ to the flotation system, the sum of flow rates of the at least one flow conforming to an initial flow rate; extracting, by a plurality of primary sampling devices, a respective plurality of first slurry samples from a respective plurality of sampling points in the froth flotation system, the plurality of sampling points being arranged to receive slurry from a respec ^¬ tive plurality of flotation cell outlets or flotation cell inlet pipes, the extracting of the plurality of first slurry samples following the determining the rate of the introduction of the ore particles into the flotation system; extracting, by a secondary sampling device, at least one second slurry sample from at least one of the plurality of first slurry samples; removing, by a filtering apparatus, ore particles from the at least one second slurry sample to obtain a sol ^¬ ids free sample; introducing, by the filtering appa ^¬ ratus, the solids free sample to an analysis device; determining, using the analysis device, a concentra ^¬ tion of the at least one collector chemical or a con- centration of at least one respective decomposition product of the at least one collector chemical from the solids free sample; computing, by the at least one flotation control computer, a difference between the concentration determined and a target concentration; determining, by the at least one flotation control computer, an updated flow rate of introduction of the at least one collector chemical into the flotation system, the rate being computed based on at least the difference computed and the rate of introduction of the ore particles into the flotation system and the average metal content mass percentage in the ore par ^¬ ticles; and controlling, by the at least one flotation control computer, the at least one electronically con ^¬ trolled valve to let the at least one respective flow of the at least one collector chemical into the flota ^¬ tion system, the sum of flow rates of the at least one flow conforming to the updated flow rate. In one example the method further comprises: transmitting information to the at least one flotation control computer on a sampling point in the froth flotation system from which the at least one second slur- ry sample is extracted; and selecting the target con ^¬ centration based on the information on the sampling point .

In one example, alternatively or in addition, the method further comprises: feeding the plurality of first samples from the plurality of primary sampling devices to the secondary sampling device.

In one example, alternatively or in addition, the plurality of flotation cell outlets comprises at least one of a tailings outlet of a rougher flotation cell, a tailings outlet of a scavenger flotation cell and a froth outlet of a cleaning flotation cell.

In one example, alternatively or in addition, the extracting of the plurality of first slurry sam ^¬ ples follows the determining of the rate of introduc- tion of the ore particles into the flotation system and the average metal content mass percentage in the ore particles after at least a predefined time.

In one example, alternatively or in addition, the predefined time corresponds to a time required for the rate of introduction of the ore particles into the flotation system to have an effect on the concentra ^¬ tion of the at least one collector chemical at the plurality of sampling points in the froth flotation system.

In one example, alternatively or in addition, the plurality of flotation cell outlets comprises the step of removing ore particles from the at least one second slurry sample to obtain the solids free sample method further comprises: pumping the at least one second slurry sample to a settling tank comprised in the filtering apparatus; allowing slurry to settle a predefined time in the settling tank in order to sub- side at least part of the ore particles; pumping a settled slurry obtained by the settling from the set ^¬ tling tank through a filter to a sample tub of the filtering apparatus from which a solution obtained from the settled liquid through the filtering is pumped to a sample vial of the analysis device.

In one example, alternatively or in addition, the method further comprises: extracting, by a condi ^¬ tioner sampling device, a conditioner slurry sample from the flow of slurry from a conditioner tank into the rougher flotation cell; and providing the conditioner slurry sample to secondary sampling device as part of the plurality of first slurry samples.

In one example, alternatively or in addition, the method further comprises: extracting, by a recy ^¬ cled process water sampling device, a recycled process water sample from a feed of recycled process water in ^¬ to the flotation system; and providing the recycled process water sample to the secondary sampling device as part of the plurality of first slurry samples or as the solids free sample to the analysis device.

In one example, alternatively or in addition, the plurality of primary sampling devices comprises at least one of a linear sampler comprising a sample cut- ter, a suction pipe sampler and a pressure pipe sam ^¬ pler .

In one example, alternatively or in addition, the plurality of primary sampling devices comprises a probabilistic sampler.

In one example, alternatively or in addition, the ore particles are introduced into a conditioner tank, the conditioner tank storing a mixture of ore particles and water, the conditioner tank providing a flow of slurry into a rougher flotation cell, the rougher flotation cell being among the plurality of flotation cells. In one example, alternatively or in addition, the flow of the at least one collector chemical con ^¬ forming to the initial flow rate or the updated flow rate is let into the conditioner tank.

In one example, alternatively or in addition, the flow of the at least one collector chemical con ^¬ forming to the initial flow rate or the updated flow rate is let into at least one of one or more flotation cells among the plurality of flotation cells, a condi- tioner tank, and a grinding mill.

An example of a froth flotation system comprises: a plurality of froth flotation cells; at least one electronically controlled valve arranged to let at least one respective flow of at least one collector chemical into the flotation system, the sum of flow rates of the at least one respective flow conforming to an initial flow rate, and arranged to let the at least one respective flow of at least one collector chemical into the flotation system, the sum of flow rates of the at least one respective flow conforming to an updated flow rate; a plurality of primary sam ^¬ pling devices arranged to extract a respective plural ^¬ ity of first slurry samples from a respective plurali ^¬ ty of sampling points in the froth flotation system, the plurality of sampling points being arranged to re ^¬ ceive slurry from a respective plurality of flotation cell outlets or inlet pipes, the extracting of the plurality of first slurry samples following a deter ^¬ mining of a rate of the introduction of the ore parti- cles into the flotation system and an average metal content mass percentage in the ore particles; a second sampling device arranged to extract at least one sec ^¬ ond slurry sample from at least one of the plurality of first slurry samples; a filtering apparatus ar- ranged to remove ore particles from the at least one second slurry sample to obtain a solids free sample, to introduce the solids free sample to an analysis de- vice; the analysis device arranged to determine a con ^¬ centration of the at least one collector chemical or a concentration of at least one respective decomposition product of the at least one collector chemical from the solids free sample and to transmit information on the concentration to at least one flotation control computer; the at least one flotation control computer communicatively connected to the at least one elec ^¬ tronically controlled valve and the analysis device; and wherein the at least one flotation control comput ^¬ er controls the at least one electronically controlled valve, determines a rate of introduction of ore parti ^¬ cles into the flotation system and an average metal content mass percentage in the ore particles, computes a difference between the concentration determined by the analysis device and a target concentration, deter ^¬ mines an updated flow rate of the at least one collec ^¬ tor chemical into the flotation system, the updated flow rate being computed based on at least the differ- ence computed and the rate of introduction of the ore particles into the flotation system and the average metal content mass percentage in the ore particles, and controls the at least one electronically con ^¬ trolled valve to let the at least one respective flow of the at least one collector chemical into the flota ^¬ tion system, the sum of flow rates of the at least one flow conforming to the updated flow rate.

An example of a froth flotation control computer comprises at least one processor and a memory storing instructions that, when executed, cause the computer to determine a rate of introduction of ore particles into the flotation system and an average metal content mass percentage in the ore particles; to control at least one electronically controlled valve to let at least one respective flow of at least one collector chemical into the flotation system, the sum of flow rates of the at least one flow conforming to an initial flow rate; to transmit at least one first signal to a plurality of primary sampling devices to cause the plurality of primary sampling devices to ex ^¬ tract a respective plurality of first slurry samples from a respective plurality of sampling points in the froth flotation system, the plurality of sampling points being arranged to receive slurry from a respec ^¬ tive plurality of flotation cell outlets or flotation cell inlet pipes, the extracting of the plurality of first slurry samples following the determining the rate of the introduction of the ore particles into the flotation system; to transmit at least one second sig ^¬ nal to a secondary sampling device to cause the sec ^¬ ondary sampling device to extract at least one second slurry sample from at least one of the plurality of first slurry samples; to transmit at least one third signal to a filtering apparatus to cause the filtering apparatus to remove ore particles from the at least one second slurry sample to obtain a solids free sam- pie; to transmit at least one fourth signal to the filtering apparatus or to the analysis device to cause the filtering apparatus or the analysis device to in ^¬ troduce the solids free sample to the analysis device; to transmit at least one fifth signal to cause the analysis device to determine a concentration of the at least one collector chemical or a concentration of at least one respective decomposition product of the at least one collector chemical from the solids free sam ^¬ ple; to compute a difference between the concentration determined and a target concentration; to determine an updated flow rate of introduction of the at least one collector chemical into the flotation system, the rate being computed based on at least the difference com ^¬ puted and the rate of introduction of the ore parti- cles into the flotation system and the average metal content mass percentage in the ore particles; and to control the at least one electronically controlled valve to let the at least one respective flow of the at least one collector chemical into the flotation system, the sum of flow rates of the at least one flow conforming to the updated flow rate.

The exemplary embodiments of the invention can be included within any suitable device, for exam ^¬ ple, including any suitable servers, workstations, PCs, laptop computers, PDAs, Internet appliances, handheld devices, cellular telephones, wireless devic- es, other devices, and the like, capable of performing the processes of the exemplary embodiments, and which can communicate via one or more interface mechanisms, including, for example, Internet access, telecommunications in any suitable form (for instance, voice, mo- dem, and the like) , wireless communications media, one or more wireless communications networks, cellular communications networks, 3G communications networks, 4G communications networks, Long-Term Evolution (LTE) networks, Public Switched Telephone Network (PSTNs), Packet Data Networks (PDNs), the Internet, intranets, a combination thereof, and the like.

It is to be understood that the exemplary em ^¬ bodiments are for exemplary purposes, as many varia ^¬ tions of the specific hardware used to implement the exemplary embodiments are possible, as will be appre ^¬ ciated by those skilled in the hardware art(s) . For example, the functionality of one or more of the com ^¬ ponents of the exemplary embodiments can be implement ^¬ ed via one or more hardware devices, or one or more software entities such as modules.

The exemplary embodiments can store infor ^¬ mation relating to various processes described herein. This information can be stored in one or more memo ^¬ ries, such as a hard disk, optical disk, magneto- optical disk, RAM, and the like. The processes de ^¬ scribed with respect to the exemplary embodiments can include appropriate data structures for storing data collected and/or generated by the processes of the de ^¬ vices and subsystems of the exemplary embodiments in one or more databases.

All or a portion of the exemplary embodiments can be implemented by the preparation of one or more application-specific integrated circuits or by inter ^¬ connecting an appropriate network of conventional com ^¬ ponent circuits, as will be appreciated by those skilled in the electrical art(s) .

As stated above, the components of the exem ^¬ plary embodiments can include computer readable medium or memories according to the teachings of the present inventions and for holding data structures, tables, records, and/or other data described herein. Computer readable medium can include any suitable medium that participates in providing instructions to a processor for execution. Such a medium can take many forms, including but not limited to, non-volatile media, vola ^¬ tile media, transmission media, and the like. Non- volatile media can include, for example, optical or magnetic disks, magneto-optical disks, and the like. Volatile media can include dynamic memories, and the like. Transmission media can include coaxial cables, copper wire, fiber optics, and the like. Transmission media also can take the form of acoustic, optical, electromagnetic waves, and the like, such as those generated during radio frequency (RF) communications, infrared (IR) data communications, and the like. Com ^¬ mon forms of computer-readable media can include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other suitable magnetic medium, a CD-ROM, CDRW, DVD, any other suitable optical medium, punch cards, paper tape, optical mark sheets, any oth ^¬ er suitable physical medium with patterns of holes or other optically recognizable indicia, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other suitable memory chip or cartridge, a carrier wave or any other suitable medium from which a computer can read.

The embodiments of the invention described hereinbefore may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the invention. A method, a froth flotation system, and a froth flotation control computer to which the invention is related may comprise at least one of the embodiments of the invention described hereinbefore.

While the present inventions have been de ^¬ scribed in connection with a number of exemplary embodiments, and implementations, the present inventions are not so limited, but rather cover various modifica- tions, and equivalent arrangements, which fall within the purview of prospective claims.

The embodiments of the invention described hereinbefore in association with the figures presented and the summary of the invention may be used in any combination with each other. At least two of the embodiments may be combined together to form a further embodiment of the invention.

It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above; instead they may vary within the scope of the claims.