[0001] This invention relates to plant for recouping metals and minerals in which slurries are treated in flotation or similar processes for recovery of the metals and minerals.

[0002] With modern ore recovering and digging processes more and more machines are used. These machines require considerable hydrocarbons (Le. oil and grease) which contaminates the ore. When this ore enters any process plant (such as a flotation process pfant) the hydrocarbons affects the process plant and metal recovery negatively.

[0003] We have found according to one aspect of the invention there is provided a metal or mineral recovery system incorporating a scrubbing system upstream of the process plant through which the slurry is passed to remove the hydrocarbons. This scrubber preferably comprises a vessel or preferably more vessels containing activated carbon and the slurry' is passed through these vessels prior to the process plant. The hydrocarbons which are in the slurry are adsorbed by the activated carbon. This reduces or removes such hydrocarbons in the slurry. As a result the operation of the process plant system is improved because the hydrocarbons are on adsorbed on the activated carbon and thus removed from the slurry.

[0004] There are preferably three to six in line carbon scrubber vessels. Each of these scrubber vessels contains a screen of 800 mhi to prevent the carbon from passing from one scrubber vessel to the next. The vessels are connected in series and the metals or mineral that are contained in the slurry' will pass through the scrubber and will pass to the process plants where the metals or minerals will be efficiently recovered because the hydrocarbons had been removed from the slurry. [0005] The vessels are preferably arranged for semi-continuous or batch operation wherein the loaded carbon is arranged to be removed from the first vessel. A similar amount of carbon is then transferred from the second vessel to the first vessel and then carbon is moved from the third vessel to the second vessel. The carbon removed from the first vessel is regenerated by stripping the hydrocarbons therefrom and it is regenerated by heat or by chemical means and the regenerated carbon is returned to the last vessel.

[0006] We have found that by removing the hydrocarbons (i.e. the oil or grease which has found its way into the ore) the process plant and especially where this is a flotation system is considerably improved.

[0007] An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

[0008] In the drawings:

Figure 1 is a block diagram showing the relevant parts of a flotation system, and

Figure 2 is a diagrammatic view of the scrubbing plant

[0009] Referring now to Figure 1 there is shown a block diagram of the relevant parts of a plant of the invention. The mined feed resources or ore which has been contaminated with hydrocarbons from the mining equipment are collected at 10. It is then transferred to a comminution plant 12 where after treatment it is mixed with liquid to form a slurry. The sluny is subjected to a preconcentration or other process step at 14 and is then lead to the process plant at 16. Intermediate the preconcentration or other process step and the flotation step the slurry is passed through a scrubbing plant 18.

[0010] The scrubbing plant comprises three adsorbsion vessels 20 arranged in series. Within each vessel is impregnated carbon. The hydrocarbons in the slurry are loaded on the impregnated carbon. Each vessel 20 has an inlet chamber 22 at its lower end into which the slurry is fed and an overflow feed 24 which leads the slurry that has passed through one vessel to the inlet chamber 22 of the next vessel. Fine screens (not shown) of 800 mm are provided at the outlet from each vessel so that the carbon is not passed on to the next vessel or to the flotation plant The carbon loaded with hydrocarbons is removed continuously or in batch amounts from the first vessel to a carbon regeneration plant 26. Carbon is then moved from the second vessel to the first vessel and from the third vessel to the second vessel. The carbon regeneration plant 26 includes a feed hopper 28 and carbon regeneration apparatus 30 where the loaded carbon is treated by heat or chemically to remove the hydrocarbons therefrom. The carbon from the regeneration apparatus 30 is passed over a carbon sizing screen 32 and the oversize (+1 mm) is then transferred to a transfer tank 34 from where it is pumped by a pump 36 to the third vessel. The undersize carbon will be removed from the circuit 35. Fresh carbon may also be fed to the transfer tank 34 via a fresh carbon attritioning tank 38.

[0011] The treated slurry which is discharged from the third scrubber tank is passed over a carbon safety screen 40 to remove the oversize containing carbon and then the underflow gravitates to a hopper 42 from which it is transferred by a pump 44 to the flotation or other process plant from which the metals or minerals are recovered. The slurry is then passed to a final tails disposal 45. [0012] Super sacks 46 and 48 are provided respectively at the sizing and safety screens 30 and 38 to collect and carry the carbon to waste or for reuse.

[0013] We have found that by treating the slurry which has been contaminated by hydrocarbons by the process described above provides the slurry to be uncontaminated and the flotation or other process will not be negatively affected by hydro carbons. The removal or reduction of hydrocarbons improves the recovery and efficiency of the process.

[0014] This invention is particularly useful where the process plant is a flotation plant

[0015] The invention is not limited to the precise constructional details as above described or as shown in the drawings. For example more than three scrubber vessels could be used, for example six vessels. There can be less vessels for example only one scrubber vessel may be used.

[0016] Any tank or vessel shape can be used for the scrubber vessels.

reference to and as illustrated in the drawings.