FIELD OF THE INVENTION

The present invention relates to underground mines , underground mining methods , and equipment for use in underground mining methods .

The present invention relates particularly to electrification of underground mines .

The present invention relates particularly, although by no means exclusively, to electrification of underground mines in the form of block cave mines .

The invention is described with particular reference to block cave mines , but also applies to other underground mines , such as sub-level caving and open stoping technologies , and also relates to other underground mines .

BACKGROUND OF THE INVENTION

Block cave mining is one of a number of underground mining technologies .

Other underground mining technologies include , by way of example , sub-level caving and open stoping technologies .

The invention applies generally to underground mining technologies , with the following description focusing on block cave mining .

Block cave mining is an efficient technology that leverages gravity and induced stress to support the efficient extraction of ore from an ore body .

In a conventional block cave mine , large sections of a rock mass are blasted at one level (the undercut level ) beneath the ore volume and extraction drives are formed at a lower level (the production or extraction level ) beneath the undercut level and a series of draw points are blasted between the production and undercut levels to allow rocks to fall through the draw points into the underlying extraction drives through which the rocks can be extracted . The rate at which rocks pass through the draw points is controlled by the rate at which rocks are removed from the extraction drives . As rocks pass through the draw points , the cave zone propagates , and the rocks collapse further to create more broken rocks to feed the draw points under the influence of gravity and induced stress .

In conventional block cave mining , large load/haul/dump ("LHD" ) vehicles are used to extract rock mass from draw points and transport rocks away from draw points to dump points , such as for (a) underground or above ground crushers or (b) larger capacity haulage options , such as conveyors or haulage vehicles , such as trucks , that transport rocks away from draw points to dump points for underground or above ground crushers .

The large size and weight of these LHD' s and trucks dictates the size of drives and requires that there be significant drives to carry the vehicles in loaded and unloaded states .

LHD' s are sized to achieve full buckets , and then must carry this payload while tramming (i . e . , 20 tonne pay load moved by a 60 tonnes vehicle) .

With increasing mining depths and rock stress , crushers/stockpiles , truck loading bays etc . , are increasingly located further away from draw points .

With increasing distances of haul routes between draw points and haulage destinations , LHD' s are becoming increasingly inefficient (high fuel costs , diesel particulate matter (DPM) emissions , maintenance and greenhouse gas emissions) .

In addition , to achieve the high production rates , LHDs travel at high speeds , increasing the risk of wall collisions and operator injury, fatigue and excessive vibration . High speed tramming in underground GPS-denied environments creates significant challenges in delivering a fully autonomous high production extraction level .

An Investor Day Briefing Book and a YouTube video of the applicant that were published in late 2018 include the sketches shown that are Figures 1-3 of this specification that disclose a block cave mining concept being researched by the applicant at that time .

The block cave mining concept , as disclosed in this document and video , includes the following features :

Mobile draw point feeders ("MDFs" ) operating at draw points in a production level of a block cave , with shovels of the MDFs moving rocks from draw points rearwardly onto upwardly and rearwardly inclined conveyors that move rocks rearwardly to discharge points that transfer rocks onto haul trucks . The haul trucks transport payloads to dump points , such as crusher tipping points , in the production level .

A perimeter drive in the production level that provides a pathway for loaded and empty haul vehicles to move between draw points and dump points .

The haul trucks , which may be autonomous and electric-powered, may be smaller in size than conventional LHD' s . When smaller haul vehicles are selected, there is an opportunity for smaller-sized drives and less extensive drive infrastructure .

The applicant has continued research and development work into the concept .

The above description and the information in the above-mentioned 2018 Investor Day Briefing Book and YouTube video are not an admission of the common general knowledge in Australia and elsewhere .

SUMMARY OF THE INVENTION

The invention was made during the course of the continuing research and development work on the block cave mine concept proposed in 2018 .

The continuing research and development work has identified opportunities for electrification of mines (including but not limited to block cave mines) by "dynamic charging" electric-powered haul vehicles and other electric-powered mine vehicles as the vehicles move in a mine .

The term "dynamic charging" is understood herein to mean electrical energy transfer to vehicles as the vehicles move in a mine , with "dynamic" indicating that typically transfer occurs as the vehicles are moving .

The continuing research and development work has also identified a more developed and viable layout of a production level of a block cave mine than that proposed in 2018 .

The applicant has realised that :

Whilst there are significant environmental , sustainability and governance ("ESG" ) benefits going from diesel -powered haul vehicles to battery-powered electric haul vehicles travelling on haul routes in underground mines , there is minimal economic value with this change after capital and other costs for changeover to and running these electric vehicles are taken into account .

There is an opportunity for additional economic value going from diesel -powered haul vehicles to dynamically- charged battery-powered electric haul vehicles in underground mines , particularly :

■ as mine depths increase and/or

■ production rates increase .

Therefore , there is an opportunity for important ESG benefits to be achieved economically .

Deeper mines mean longer declines for vehicle travel .

A higher production rate is possible with dynamic electrical energy transfer because it is not necessary to lose time changing out batteries or charging batteries while vehicles are stationary .

Also , there will not need to be as many batteries on each haul vehicle - therefore , haul vehicles will have a lower cost and less mass .

■ This has a flow-on effect on civil engineering requirements for drives . Dynamic electrical energy transfer provides an opportunity to drive electric motors directly .

■ This is more efficient and can provide more power than by energy transfer to batteries and then drawing power from the batteries to drive motors .

■ Charging and discharging batteries impacts battery life - stresses batteries .

In overall terms , moving to dynamic charging electrically-powered haul vehicles on haul routes opens up opportunities to operate haul vehicles that can travel faster than is possible with current vehicles , particularly on declines , and therefore increase production rates .

A high proportion of the electrical power that is needed to run haul vehicles and other electrically- powered mine vehicles in a mine is required to move loaded vehicles up declines .

■ Therefore , it makes sense , although it is not essential to the invention , to position dynamic electrical energy transfer assemblies on declines .

One option is to dynamically charge a loaded vehicle as it moves up a decline so that it has sufficient stored battery power , for example , no more than 75+% charge , at the top of the decline to operate aboveground and to capture and store all available regenerative braking energy as the vehicle travels down the decline and not lose an opportunity to capture all of this energy .

■ A higher charge at the top of a decline is not required because batteries can pick up regenerative braking energy (that is stored in batteries) as a vehicle is driven down the decline to return to a production level .

The back , i . e . , roof , is the best place for dynamic electrical energy transfer rails used, for example , in the slotted electric rail system developed by BluVein Innovation AB described further below . ■ Side walls are also a less preferred but potentially viable option .

■ Roads are a least preferred but still potentially viable option .

It is possible that there will be a move away from new crushers in mine expansions or to minimise the numbers of crushers in new mines and expansion plans for those mines .

The reasons for a possible move away from underground crushers include :

■ The substantial cost to construct underground crushers (i . e . , the time to get access to crushers .

■ An opportunity for quicker access to valuable metals in a mine by not building an underground crusher .

■ The potential seismic impact of an underground crusher .

One consequence of moving away from underground crushers is that it is likely that haul vehicles will have to tram rocks for longer distances (such as > 300m, > 400m, > 500m, and > 600m) from expansion block caves in existing mines to crushers servicing existing block caves .

This means that there will be a need for new drive layouts to transport rock from extraction points (such as draw points) and dump points efficiently and safely .

It is likely that block cave and other underground mines will be deeper in the future , with a result that there will be longer haulage distances in the declines in underground mines in the future .

The invention is based on a realisation that dynamic electrical energy transfer to electrically-powered haul vehicles (and other electrically-powered underground mine vehicles) is an opportunity to minimise battery capacity on these vehicles and to run the longer flat and decline distances that will be required in mine expansions and new mines and at higher vehicle speeds on flat sections and up declines (for example , typical 8kmh now versus 20 kmh) of haul routes , leading to higher overall production rates .

The invention provides an underground mine for mining a volume of a rock mass , such as but not limited to a block cave mine , that includes :

(a) a production level that includes one or more extraction points for rock extraction ;

(b) a haul route from the extraction point (s) to a dump point ; and

(c) a dynamic electrical energy transfer assembly located in the mine for directly powering electric motors of electric-powered mine vehicles , such as electric-powered haul vehicles , and/or charging batteries of electric- powered mine vehicles as they move through the mine .

It is noted that the invention extends to (a) underground mines that operate with fully electric-powered vehicles and (b) underground mines that have vehicles that are powered via a combination of electric and non-electric energy sources .

It is also noted that the invention extends to mines that operate with electric-powered mine vehicles and other vehicles that are powered by non-electric energy sources , such as diesel vehicles .

The dynamic electrical energy transfer assembly may be located in a section of the haul route in the production level .

The dynamic electrical energy transfer assembly may be located advantageously where maximum benefit can be obtained from electrical power delivered directly to electric-powered mine vehicles .

The dynamic electrical energy transfer assembly may be located in a section of a decline or another part of the haul route that interconnects the production level and a higher or a lower level in the mine or above-ground . This is an advantageous location in those instances where a significant amount of the total energy required to move electric-powered mine vehicles in a mine is required to move the vehicles up a decline .

The interconnecting sections of a mine are often referred to as "declines" or "ramps" and may be any gradient depending on a given mine .

The interconnecting sections of a mine are hereinafter referred to as "declines" .

The term "electric-powered mine vehicles" is understood herein to mean any electric-powered vehicles that are used in underground mines , such as electric- powered haul vehicles (including trucks and load-haul -dump ("LHD" ) vehicles or trolleys) , loaders , dozers , and ancillary fleets , etc . The term also covers vehicles that are "hybrid" vehicles in that they can operate via electric power or via other energy sources , such as diesel .

The term "production level" is understood herein to mean a section of an underground mine from which rock mass can be removed from the mine .

The dynamic electrical energy transfer assembly may be any suitable dynamic electrical energy transfer assembly .

Typically, when operating , electric-powered haul vehicles move between extraction points and the dump point , with electric motors of the vehicles being powered directly and/or batteries of the vehicles being charged by the dynamic electrical energy transfer assembly as the vehicles move through the mine , whereby in use the vehicles :

(a) are loaded with rocks at the extraction points by loading units , for example by mobile draw point feeders , located at the extraction points ,

(b) transport rocks in the electric-powered haul vehicles as described herein to and discharging rocks at the dump point ; and (c) return empty electric-powered haul vehicles to the extraction points to be re-loaded with rocks .

The underground mine may be any suitable underground mine .

By way of example , the underground mine may be any one of a block cave mine , a sub-level cave mine , and an open stope mine .

In a situation where the underground mine is a block cave mine , the production level may include a plurality of extraction points in the form of draw points , a plurality of parallel extraction drives , and a plurality of parallel draw point drives that are perpendicular or transverse to the extraction drives , with draw points communicating directly with draw point drives .

The haul route may include a perimeter drive that extends at least a part of the way around an outer perimeter of the area of the draw points and interconnects at least some of the extraction and draw point drives to facilitate movement of electric-powered haul vehicles between the extraction points and the dump point .

The haul route may also include any one or more than one of an ore body access drive , a cross-cut drive , a footwall drive , and a hanging wall drive that facilitate movement of electric-powered haul vehicles between the extraction points and the dump point .

The dump point may be a crusher tipping point , ore pass , stockpile or other rock processing unit operation above or below ground .

The dump point may be a transfer location at which rock mass is transferred from one haul vehicle to another haul vehicle for subsequent transportation to another dump point .

The dump point may be a vertical ore pass where material is tipped down to a lower level for subsequent re-handling or loading to a form of transportation (i . e . . truck , rail , conveyor , etc) . The dynamic electrical energy transfer assembly may be located at any suitable location in the haul route , including the above-mentioned declines , perimeter drive , ore body access drive , cross-cut drive , footwall drive , and hanging wall drive .

By way of example , the dynamic electrical energy transfer assembly may be located in the perimeter drive of the haul route of the production level .

The perimeter drive of the haul route of the production level is well-suited as a location for the dynamic electrical energy transfer assembly, particularly when the perimeter drive has sections that allow sufficient time for electric haul vehicles or other electric vehicles to operatively engage the dynamic electrical energy transfer assembly and be charged as the vehicles continue to move along the perimeter drive .

As noted above , declines are also well-suited as a location for the dynamic electrical energy transfer assembly in situations where electric-powered haul vehicles (and other electric-powered mine vehicles) need to drive to dump points at higher levels of the mine or to above-ground dump points . In this situation , a major power requirement for electric-powered haul vehicles is to be able to move up the decline , typically quickly .

The dynamic electrical energy transfer assembly and the electric-powered haul vehicles or other electric- powered vehicles may be configured to supply electrical energy directly to electric motors of the electric-powered haul vehicles or other electric-powered vehicles as they move up the decline .

The dynamic electrical energy transfer assembly and the electric haul vehicles may be configured to supply a part of the electrical energy directly to electric motors of the electric-powered haul vehicles or other electric vehicles as they move up the decline and another part of the electrical energy to charge on-board batteries of the electric-powered haul vehicles or other electric vehicles . The dynamic electrical energy transfer assembly and the electric haul vehicles may be configured to supply electrical energy directly to electric motors of the electric-powered haul vehicles or other electric-powered vehicles while the electric-powered vehicles are stationary . Examples of such situations are while a vehicle is stationary for a period of time as it approaches a crusher , while tipping at the crusher , and while departing the crusher .

The dynamic electrical energy transfer assembly may be any suitable assembly .

By way of example , the dynamic electrical energy transfer assembly may be a slotted electric rail system.

By way of example , the slotted electric rail system may be of the type developed by BluVein Innovation AB - see Bluvein website and International publications W02016/174030 (PCT/EP2016/059278) , WO2022/188993 (PCT/EP2021/056376) , WO2022/096112 (PCT/EP2020/081193) , WO2022/096115 (PCT/EP2020/081199) , WO2022/096665 (PCT/EP2021/080811 ) and PCT/AU2021/050738 (WO2023/279135) , the disclosures of which are incorporated herein by cross reference .

The slotted electric rail system may be mounted to a roof of the perimeter drive .

The slotted electric rail system may be mounted to or adjacent a side wall of the perimeter drive .

Typically, and advantageously, the slotted electric rail system is mounted near to the ground adjacent the side wall of the perimeter drive .

Typically, the term "near to the ground" means that the slotted electric rail of the system is less than 1 . 8m, more typically, less than 1 .5m, above the ground .

The production level may include a plurality of 1 ^st branch drives that connect the perimeter drive to entrances to the extraction drives .

The production level may include a plurality of 2 ^nd branch drives that connect the exits of the extraction drives to crusher tipping points or other rock processing unit operations .

The electric-powered haul vehicle may be any suitable vehicle .

For example , the electric-powered haul vehicle may be a truck .

By way of further example , the electric-powered haul vehicle may be an electric-powered hauler , for example as manufactured by Volvo , including autonomous electric haulers which enable increased vehicle densities , faster cycle times and significant efficiency gains to deliver step-change improvements in cave extraction rates and mining costs .

By way of further example , the electric-powered haul vehicle may be an electric-powered LHD .

By way of further example , the electric-powered haul vehicle may be a carrier shuttle vehicle , such as a Volvo prototype "HX02" carrier or a "TARA." platform.

The layout of the production level and the mine generally makes it possible to have one-way movement only of electric-powered haul vehicles in drives and thereby minimise risks of collisions in drives .

A plurality of the electric-powered haul vehicles may be configured to be coupled together to move in a peloton arrangement .

The mine may include a loading unit , such as in the form of a dig/load unit , at the or each extraction point , such as a draw point in a block cave mine , for transferring rock from draw points to electric-powered haul vehicles .

The loading unit may be any suitable loading unit , such as a LHD , powered by any suitable energy source (including electric , biodiesel , fossil diesel , synthetic e-fuels , hydrogen , methanol , and ammonia) .

The dig/load unit may include a plurality of mobile draw point feeders at draw points , with the mobile draw point feeders having upwardly inclined conveyors that have a lower feed end and an upper discharge end that are positioned to receive rock mass from draw points at the feed ends and transport rock mass along the conveyors and discharge rocks from the discharge ends onto electric- powered haul vehicles .

It may be possible to move electric-powered haul vehicles to and from discharge points of dig/load units so that there is at least substantially continuous transfer of rocks from extraction points to electric-powered haul vehicles .

Conventional LHD-based loading and hauling activity in block cave mines involves a batch process where a single load is picked up by a LHD at a draw point and transported by the LHD from the draw point to a tip point/crusher/conveyor before the LHD returns empty for a second batch and so on .

The invention extends to operating with electric- powered LHDs and locating the dynamic electrical energy transfer assembly in the path of movement of the LHDs .

The invention provides an opportunity for continuous flow of rocks from draw points .

The dig/load unit separates the dig/loading functions at locations where there is mined material and transport functions that are required to move rocks from the locations to crushers or other end use locations . The dig/loading function is handled by dig/load units that are optimised to carry out the loading function . The transport function is carried out by electric-powered haul vehicles that are optimised for this purpose .

The invention makes it possible to use vehicle control systems that are focussed on enabling dispatch and control of multiple haulage vehicles that receive rocks from mobile draw point feeders which stay at or near draw points .

The invention makes it possible to operate with considerably less underground infrastructure , such as drives , drive supports , drive infrastructure , and with smaller vehicles than have been required in conventional block cave or other underground mines .

In addition to crusher tipping points mentioned above , the other rock processing unit operations for the rocks transported on the electric-powered haul vehicles may include conveyors for transporting rocks to underground or above-ground crushers or to above-ground stockpiles .

The invention makes it possible to use a fleet of lighter and more efficient electric-powered haul vehicles rather than conventional LHD' s .

These lighter and more efficient electric-powered haul vehicles make it possible to operate in smaller drives , reducing drive development and ventilation costs , and place less demand on drive surfaces within the drives .

Significantly, the potential to downsize infrastructure footprints and dimensions provides opportunities for stronger tunnels that are less prone to seismicity and seismic damage .

The invention makes it possible to avoid the bottlenecks of the conventional loader/bogger system as the haulage function is separated from the dig/loading function and dispersed amongst multiple haulage vehicles in the invention .

The invention makes it possible to adjust the specific geometry of the production level to suit maximum efficiency for movement of haulage vehicles be it grid, herringbone or 'el teniente' layout or any other suitable design .

Currently, block cave extraction horizons are generally set-up for the use of LHDs . LHD vehicles are inefficient in the haulage function and, therefore , going forward there is an opportunity to use a variety of haulage options (LHD and/or mobile draw point feeder type machines) to load haul vehicles which will convey rock to the tip point/ore pass . This provides an opportunity to improve production efficiency, energy efficiency and enables efficient autonomous/semi-autonomous/tele- remote/manned operations . Other benefits include reduced diesel burn/reduced ventilation requirements/reduced drive dimens ions /improved geotechnical stability of drives in high stress/poor rock mass condi tions/reduced ground support requirements/reduced excavation requirements during production level establishment .

The invention also extends to underground mines operating on a hybrid basis , with (a) one part of the mine operating in accordance with the invention and (b) another part of the mine operating conventionally, for example with diesel -powered LHDs carrying out the dig/load/ transport functions and transporting and delivering rock mass from draw points to dump points above or below ground .

The invention also provides a method of mining a volume of a rock mass in the above-described underground mine that includes :

(a) transporting rocks on a plurality of electric- powered haul vehicles as described herein from extraction points , such as draw points , to a dump point above or below ground,

(b) discharging rocks at the dump point ;

(c) returning the electric-powered haul vehicles to extraction points and repeating steps (a) and (b) ; and

(d) dynamically transferring electrical energy to the electric-powered haul vehicles as they move along a pathway in the production level or elsewhere in the mine or as they are stationary, for example at a dump point .

Step (d) may include dynamically transferring electrical energy to directly power electric motors of the vehicles .

Step (d) may include dynamically transferring electrical energy to charge batteries of the vehicles . Step (d) may include a combination of dynamically transferring electrical energy to directly power electric motors of the vehicles and dynamically transferring electrical energy to charge batteries of the vehicles .

The underground mine may be any suitable underground mine .

By way of example , the underground may be any one of a block cave mine , a sub-level cave mine , and an open stope mine .

The invention also provides an operating underground mine that mines a volume of a rock mass that includes :

(a) a production level that includes one or more extraction points for rock extraction ;

(b) a haul route from the extraction point (s) to a dump point ;

(c) a plurality of electric-powered mine vehicles , such as electric-powered haul vehicles , operating in the mine , and

(d) a dynamic electrical energy transfer assembly located in the mine and directly powering electric motors of the electric-powered mine vehicles and/or charging batteries of the electric-powered mine vehicles as they move through the mine .

The haul route may include a decline or another part of the haul route that interconnects the production level and a higher or lower level in the mine or above-ground, and the dynamic electrical energy transfer assembly may be located on the decline and configured to transfer power to electric-powered mine vehicles as they move up the decline .

The haul route may include a perimeter drive that extends at least a part of the way around an outer perimeter of the area of the draw points and interconnects at least some of the extraction and draw point drives to facilitate movement of electric-powered haul vehicles between the extraction points and the dump point , and the dynamic electrical energy transfer assembly may be located in the perimeter drive .

The underground mine may be any suitable underground mine .

By way of example , the underground may be any one of a block cave mine , a sub-level cave mine , and an open stope mine

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more fully explained embodiments of block cave mining methods and mines are described with reference to the accompanying drawings , in which :

Figures 1 is a very diagrammatic view of a section of a block cave mine that is in the above-mentioned Investor Day Briefing Book and YouTube video of the applicant that were published in late 2018 ;

Figure 2 is an enlargement of a section of the production level of the mine shown in Figure 1 ;

Figure 3 is a diagram that has two sections , one of which illustrates a draw point and an extraction drive at the production level of the mine shown in Figures 1 and 2 , and the other of which illustrates a mine operations station with equipment receiving and processing sensed data from the mine ; and

Figures 4 -15 illustrate in diagrammatic form several embodiments of a block cave mine and a mining method in accordance with the invention .

DESCRIPTION OF EMBODIMENTS

As noted above , Figures 1-3 illustrate an early concept of the applicant , which was published in 2018 , that has been developed further by the applicant in the process of making the invention .

Figures 1-3 show a section of a block cave mine , generally identified by the numeral 3 , that includes : (a) a section of a volume 5 of a rock mass to be mined (the "mine volume" ) ;

(b) a plurality of position beacons 51 located in the mine volume 5 that move downwardly with fragmented rock mass as mining continues and make it possible to track movement of fragmented rock mass through the volume ;

(c) a production level 9 for extracting rock mass from the mine volume 5 , with the production level 9 including a plurality of parallel extraction drives 11 , a plurality of parallel draw point drives 13 , and an outer perimeter drive 7 ;

(d) a plurality of extraction points in the form of draw points 27 for funnelling rocks from the mine volume 5 into the draw point drives 13 ;

(e) dump points , in this instance in the form of crusher tipping points 17 , for receiving rocks from draw points 27 on the production level 9 ;

(f) a conveyor assembly 15 for receiving rocks from the tipping points 17 and transporting the rocks to a crusher (not shown) located at a level below the production level 9 or above-ground;

(g) an arrangement of operator-driven , autonomously or tele-remotely operated vehicles , including (i ) loading units in the form of mobile draw point feeders 19 at draw points 27 and (ii ) haul vehicles 29 for transporting rocks away from the draw points 27 ; and

(h) an above-ground operator control centre , generally identified by the numeral 21 (Figure 3) , for monitoring and controlling the operation of the vehicles 19 , 29.

The mine operations centre 21 includes equipment that receives , and processes , sensed data from the position beacons 51 in the mine volume 5 and other sensors in the mine . These sensor and processing systems provide useful data about the rocks to facilitate more effective downstream processing of the mined material . The mine 3 also includes a hydraulic fracturing assembly for fracturing rock mass in the mine volume 5 by pumping hydraulic fluid downwardly into the mine volume 5 from suitable vehicles 63 located in an upper level 61 of the mine .

Typically, the mine also fractures the rock mass in the mine volume 5 by detonating explosives (not shown) in bore holes 65 drilled upwardly from the extraction drives 11 in the production level 9 of the mine 3.

As noted above , the invention is based on a realisation that dynamic electrical energy transfer to electrically-powered haul vehicles (and other electrically-powered underground mine vehicles) is an opportunity to minimise battery capacity on these vehicles and to run the longer flat and decline distances that will be required in mine expansions and new mines and at higher vehicle speeds on flat sections and up declines (for example , typical 8kmh now versus 20 kmh) of haul routes , leading to higher overall production rates .

Figures 4 -15 illustrate in very diagrammatic form several embodiments of a block cave mine and a mining method in accordance with the invention , noting that the invention is not confined to block cave mines and extends to underground mines generally .

The same reference numerals are used in these Figures to describe the same features that are described in Figures 1-3.

Figure 4 shows diagrammatically and in a simplified form a mine , generally identified by the numeral 3 , that has a plurality of production levels 9 for extracting rocks from volumes of rock mass to be mined (the "mine volume" ) located above the production levels 9 - not shown explicitly in the Figures , but the same as shown in Figures 1-3.

The mine 3 also includes a decline 45 that interconnects the production levels 9 and the surface 47 and an above-ground processing plant 57 on the surface 47 . It is noted that the production levels 9 may be associated with different sections of a block cave that are developed with expansion of a mine 3.

It is also noted that there may be more than one decline 45 in other embodiments .

The processing plant 57 may include any required unit operations to recover a valuable metal from rocks that are mined underground and transported to the processing plant 57 . For example , the processing plant 57 may include a crusher circuit (not shown) and a flotation plant for producing a concentrate containing valuable material . This is one example of a number of examples .

In the embodiment shown in Figure 4 , rocks that are discharged from the extraction points in the form of draw points 27 on production levels 9 and are loaded into electric-powered haul vehicles 29 that transport the rocks to and then up the decline 45 and then directly to the processing plant 57 or to a stockpile 65 or to one of a number of stockpiles 65 . The stockpile (s) 65 may be a waste rock stockpile or a valuable rock stockpile that , ultimately, transfers rocks to the processing plant 57 .

After the rocks in the haul vehicles 29 are unloaded at the processing plant 57 or the stockpile (s) 65 , the haul vehicles 29 return to the production levels 9 to repeat the above cycle of loading rocks from draw points 27 , transporting the rocks above ground via the decline 45 , unloading rocks , and returning empty to the production level 9 .

The haul vehicles 29 include on-board batteries 61 that can store electrical power and electric motors 63. The electric motors 63 are configured to be powered via the batteries 61 or via a dynamic electrical energy transfer assembly 37 , depending on the circumstances .

The embodiment shown in Figure 4 includes a dynamic electrical energy transfer assembly 37 located at least in one section of the mine 3 . The dynamic electrical energy transfer assembly 37 may be any suitable system.

For example , the dynamic electrical energy transfer assembly 37 may be a slotted electric rail system, such as a slotted electric rail system developed by BluVein Innovation AB .

In the Figure 4 embodiment , the dynamic electrical energy transfer assembly 37 is located in the decline 45 .

However , alternatively or in addition , the dynamic electrical energy transfer assembly 37 may be located elsewhere in the mine 3 , for example in sections of the production levels 9 - discussed further in relation to the embodiments in Figures 5-15 .

One factor in selecting the location or locations of the dynamic electrical energy transfer assembly 37 is to locate the dynamic electrical energy transfer assembly 37 where maximum benefit can be obtained from electrical power delivered directly to a haul vehicle 29. One such location is on a decline 45 where a significant amount of the total energy required to move haul vehicles 29 in a mine is often required to move the haul vehicles 29 up a decline .

Another factor in situations where haul vehicles 29 have batteries 61 , is to minimise the battery requirements for a vehicle and therefore reduce the total mass of the vehicle without compromising the operating effectiveness of the vehicle . A relevant consideration is to minimise the travel time for haul vehicles 29. Stopping for battery change-outs or solely for static charging of batteries 61 inevitably increases travel time .

Figure 4 shows that the dynamic electrical energy transfer assembly 37 is located along the whole of the length of the decline 45 . In other embodiments , the dynamic electrical energy transfer assembly 37 is located at one or more locations along the length of the decline 45 .

The dynamic electrical energy transfer assembly 37 is configured to supply power directly to haul vehicles 29 to move the haul vehicles 29 up the decline 45 . The dynamic electrical energy transfer assembly 37 is also configured to supply power to the batteries 61 of the haul vehicles 29 to charge the batteries 61 as the haul vehicles 29 move up the decline 45 .

Figure 4 also shows that the mine 3 is configured to take advantage of regenerative braking on the haul vehicles 29 to capture kinetic energy from braking of haul vehicles 29 as they travel down the decline 45 and convert it into electrical power and transfers the power to the batteries 61 of the haul vehicles 29 as haul vehicles 29 move down the decline 45 to the production level (s) 9.

Figure 4 also shows that power from the batteries 61 of the haul vehicles 29 drives the electric motors 63 of the vehicles and moves the vehicles on the flat , i . e . , on the production levels 9 or on other areas of the mine 3 that have flat sections .

It is noted that a crusher (not shown) may be located below ground in other embodiments , with rocks being transported by haul vehicles 29 from the draw points 27 to the crusher and crushed rock being transported by other haul vehicles 29 up the decline 45 to the processing plant 57 or to the stockpile 65 .

It is also noted that the haul vehicles 29 are examples of vehicles that can be operated as electric- powered vehicles in the mine 3 and that can take advantage of electric power supplied via the dynamic electrical energy transfer assembly 37 . Other examples include drill rigs , graders , shotcrete trucks , rock bolters and other vehicles that can be described as being part of an ancillary fleet for a mine .

The haul vehicles 29 may be any suitable electric- powered vehicles including LHDs , trucks , and trolleys . Therefore , it is understood that description of the embodiments that is focused on haul vehicles 29 applies equally to these other underground mining vehicles . These vehicles may be autonomously or tele-remotely operated vehicles .

The mine 3 shown in Figure 4 also includes an aboveground mine operations station (not shown) and an explosives initiated fracturing technology of the types described above in relation to Figures 1-3.

As noted above , continuing research and development work of the applicant has identified a more developed and viable layout of a production level of a block cave mine to that disclosed in Figures 1-3 and an opportunity to use dynamic electrical energy transfer directly to electric motors of electric-powered haul vehicles and/or to batteries of electric-powered haul vehicles in the production level 9 .

Figures 5-15 show a section of a block cave mine 3 , that includes :

(a) a volume of a rock mass to be mined (the "mine volume" ) - not shown explicitly in the Figures , but the same as shown in Figures 1-3 ;

(b) a production level 9 for extracting rocks from a section of the mine volume 5 that is located above the production level 9 ;

(c) a haul route comprising (i ) a plurality of parallel extraction drives 11 , (ii ) a plurality of parallel draw point drives 13 , (iii ) an outer perimeter drive 7 , (iv) a plurality of 1 ^st branch drives 31 that connect the perimeter drive 7 to entrances to the extraction drives 11 (in the nominated direction of movement of vehicles into the extraction drives 11 ) , and (iv) a plurality of 2 ^nd branch drives 33 that connect the exits of the extraction drives 11 to dump points , in this instance a crusher tipping point 17 or other rock processing unit operations (not shown) ;

(d) a plurality of extraction points in the form of draw points 27 for funnelling rocks from the mine volume into the draw point drives 13 ; (e) an underground dump point in the form of the crusher tipping point 17 for receiving rocks from draw points 27 , with the tipping point 17 transferring rocks to an underground crusher (not shown) directly or via a conveyor (not shown) ;

(f) an arrangement of vehicles , typically autonomously or tele-remotely operated vehicles , including mobile draw point feeders 19 at draw points 27 in the draw point drives 13 and electric-powered haul vehicles 29 (such as LHDs , trucks , and trolleys) moving along extraction drives 11 , draw point drives 13 , the outer perimeter drive 7 , transporting rocks away from the draw points 27 ; and

(g) a dynamic electrical energy transfer assembly 37 (see Figures 10 and 11 ) , located in sections of the perimeter drive 7 of the production level 9 and in sections of drives approaching the crusher tipping point 17 (or any other suitable location in the production level 9 for charging electric-powered haul vehicles 29 (and other electric-powered mine vehicles) as they move through the production level 9 .

The haul route also includes a "decline" (not shown) that interconnects the production level and a higher level in the mine or above-ground - as described in relation to the Figure 4 embodiment .

As described in relation to the Figure 4 embodiment , the dynamic electrical energy transfer assembly 37 may be located in the decline 45 in situations where electric- powered haul vehicles 29 (and other electric-powered mine vehicles) need to move along the decline to transport rocks to an above-ground processing plant 57 or to a stockpile (s) 65 . It is noted that the decline 45 may also be used for other purposes , such as for haul vehicles 29 to move rocks to a crusher located at another level of the mine .

The other electric-powered mine vehicles may be any other electric-powered vehicles that are used in block cave mines , such as loaders , dozers , and ancillary fleets , etc .

The block cave mine 3 typically includes an aboveground mine operations station (not shown) of the type described above in relation to Figures 1-3 which includes equipment that receives , and processes sensed data from the position beacons 51 in the mine volume 5 and other sensors in the mine 3 , such as grade (direct or indirect) sensors 53 at the draw points 27 . These sensor and processing systems provide useful data about the rocks to facilitate more effective downstream processing of the mined material . In particular , the overall system makes it possible to start to separate valuable and less valuable mined material at the earliest possible stage .

The block cave mine 3 typically also includes the hydraulic and explosives initiated fracturing technology described above in relation to Figures 1-3.

In the embodiment shown in Figure 12 , the dynamic electrical energy transfer assembly 37 includes an overhead slotted electric rail element 39 extending along a section of the perimeter drive 7 . The slotted electric rail system may be , by way of example , the above-mentioned BluVein system.

In the embodiment shown in Figures 7 , 13 , and 15 the dynamic electrical energy transfer assembly 37 includes a side-mounted slotted electric rail 41 .

It is noted that the dynamic electrical energy transfer assembly 37 may be side , roof , shoulder or even floor-mounted depending on the application . An all-terrain arm 67 and collector (Figures 12 and 13) attaches to the slotted rail element 39.

With reference to Figures 5 and 6 , a key feature of the more developed layout of the production level 9 is a combination of a perimeter drive 7 and the dynamic electrical energy transfer assembly 37 located in a section or sections of the perimeter drive 7 for charging electric-powered haul vehicles 29 (and other electric- powered vehicles) as they move through the mine 3. The straight sections of the perimeter drive 7 are one (but not the only) suitable location for the dynamic electrical energy transfer assembly 37 .

In these Figures , the haul vehicles 29 are in the form of trucks . The haul vehicles 29 may be any other suitable haul vehicles .

In these Figures , the dynamic electrical energy transfer assembly 37 includes a side-mounted slotted electric rail 41 . In other embodiments , the slotted electric rail 41 may be roof , shoulder or even floormounted .

The dynamic electrical energy transfer assembly 37 is configured to directly drive electric motors of the haul vehicles 29 and/or charge on-board batteries of the haul vehicles 29 as they move along the section (s) of the perimeter drive 7 .

With reference to Figures 7 and 15 , the dynamic electrical energy transfer assembly 37 is also configured to directly drive electric motors of the haul vehicles 29 and/or charge on-board batteries of the haul vehicles 29 as they move towards the crusher tipping point 17 along exit drives 33 of the haul route or are stationary in a queue to travel to the crusher tipping point 17 . In these Figures , the haul vehicles 29 are in the form of electric- powered LHDs . The haul vehicles 29 may be any other suitable electric-powered haul vehicles . In these Figures , the dynamic electrical energy transfer assembly 37 includes a side-mounted slotted electric rail 41 . In other embodiments , the slotted electric rail 41 may be roof , shoulder or even floor-mounted .

As is noted in relation to the Figure 4 embodiment , the dynamic electrical energy transfer assembly 37 makes it possible to eliminate the requirement for stoppages for static charging (where there is no other reason to be stationary) or battery changes etc .

As noted above , Figures 5-15 illustrate draw points 27 communicating with extraction drives 11 and draw point drives 13 in the production level 9 of the mine and mobile draw point feeders 19 located in draw point drives 13 and receiving rocks from the draw points 27 .

The mobile draw point feeders 19 are track -mounted units in this embodiment that can be driven into and backed out of draw point drives 13 and manoeuvred as required in the draw point drives 13 to position the mobile draw point feeders 19 for optimum removal of rocks . Each mobile draw point feeder 19 may include an operator cabin (not shown) or may be remotely controlled .

The mobile draw point feeders 19 transfer rocks in rill piles in the draw point drives 13 that form after rocks have moved through the draw points 27 into the draw point drives 13.

Each mobile draw point feeder 19 includes a conveyor 43 and a framework that supports the conveyor 43. The conveyor 43 extends rearwardly and upwardly from a lower inlet end to an upper discharge end . The inlet end includes a feed chute 51 that is wider than the conveyor width and facilitates feeding rocks onto the conveyor 43. The discharge end is a goose-neck arrangement 53. Each mobile draw point feeder 19 includes a hydraulic ram assembly that supports the conveyor 43 at the discharge end and approximately 1/3 of the length of the mobile draw point feeder 43 from the inlet end to the discharge end . The ram assemblies facilitate adjustment of the angle of inclination of the conveyor 43. Each mobile draw point feeder 19 includes a shovel 55 on the end of an articulated arm, with the articulated arm being connected at the other end to the support framework . In use , the shovel may be operated as required to move rock , onto the conveyor 43.

In one embodiment, the mobile draw point feeder 19 is manoeuvred so that the feed chute 51 extends at least part way under the rocks at a draw point . In this position , movement of rocks on the conveyor results in downward movement of new rocks onto the conveyor 43. In another embodiment , the mobile draw point feeder is positioned slightly away from the rock pile at a draw point and the shovel 55 is used to move rock mass onto the feed chute 51 and then the conveyor 43. A further embodiment relies on a combination of the previous embodiments to load the conveyor 43. In general terms , it is envisioned that the use of the shovel 55 will be reserved for situations where there are large rocks to manoeuvre onto the conveyor 43.

In use , the conveyors 43 of the draw point feeders 19 transport rocks upwardly from the draw points 13 to discharge ends of the mobile draw point feeders 19. The rocks are transferred to the electric-powered haul vehicles 29 shown in the Figure . When loaded, the vehicles 29 transport the rocks to crusher discharge chutes 17 .

Figures 5-15 illustrate two embodiments of electric- powered haul vehicles 29 in use in the extraction drives 11 . The invention is not confined to these embodiments . One vehicle is a relatively small electric-powered shuttle that is basically an autonomously or remotely operated wheel or track -mounted bin for receiving and transporting rocks . One example of an electric-powered shuttle is an electric-powered hauler manufactured by Volvo - such as a Volvo prototype HX02 carrier .

The other electric-powered haul vehicle 29 is an electric-powered truck with a larger payload than the electric-powered shuttle .

The invention extends to the use of any suitable electric-powered vehicles for use in underground mines .

With reference to Figures 9 and 11 , continuous loading of rocks is possible with the haul vehicles 29 facing in any direction (e . g . , side , rear) . This makes it possible to use multiple electric-powered haul vehicles 29 with ore waste separation . The mobile draw point feeders 19 and the haul vehicles 29 also make it possible to use on-belt grade or other parameter sensing or scanning for real time information on rock/grade properties .

In use , after a block cave mine 3 is established, the operations centre initiates and then controls :

(a) the operation of the mobile draw point feeders 19 at selected draw points 27 ;

(b) movement of the haul vehicles 29 along the perimeter drive 7 , the entrance drives 31 , and the extraction drives 11 to the selected draw points 27 ;

(c) loading of the haul vehicles 29 with rocks via the mobile draw point feeders 19 ,

(d) movement of loaded haul vehicles 29 through the exit drives 33 to the crusher tipping point 17 and discharging the load of rocks in the haul vehicles 29 at this location ;

(e) repeating steps (a) to (d) ; and

(f) dynamic charging of haul vehicles 29 as required as the vehicles move along the perimeter drive 7 .

Advantages of the embodiments shown in Figures 4 -15 include the following advantages .

• A system that makes it possible to realise significant ESG benefits , for example via increased electrification of underground mines and less reliance on the use of diesel -powered vehicles .

• A system that is more amenable to automation : potential for elimination of operators from draw point exposures through adoption of teleremote /autonomous systems ; potential for elimination of the need for manned high speed LHD tramming and associated safety issues ;

• Step change productivity improvements over conventional LHD systems by de-bottlenecking the production area constraints . This is possible via the use of a perimeter drive 7 and the branch drives 31 , 33 defining a clear one-way path of movement of electric-powered haul vehicles 29 between the crusher tipping point 17 and the discharge points for mobile draw point feeders 19 , mobile draw point feeders 19 positioned and operating in the draw point drives 13 and not having to operate in extraction drives 11 , and the dynamic electrical energy transfer assembly 37 making it possible to charge electric-powered haul vehicles 29 while the vehicles are moving and therefore without any production down-time .

• An electrified system making it possible to shift , for example , to lighter weight , high efficiency haulage vehicles 29 that can deliver an efficient , low cost , zero DPM and low greenhouse gas intensity haulage solution .

• An opportunity to use less expensive haulage vehicles 29 and other mine vehicles that operate at higher productivities that can match or exceed productivities of current vehicles .

• Potential for less time queuing , loading , tipping , etc .

• Potential for faster haulage speeds .

• Potential for more easier system automation .

• Potential for lower capital and operating cost . For example , an opportunity to make infrastructure savings in new crusher construction , earlier production because there are fewer new crushers , infrastructure savings in ventilation and battery change-outs .

Many modifications may be made to the embodiments of the invention described in relation to the Figures without departing from the spirit and scope of the invention .

By way of example , as noted above , whilst the above description in relation to the Figures focuses on block cave mining , the invention is not limited to block cave mines and extends generally to underground mines . Other underground mines include , by way of example , sub-level cave mines and open stope mines . By way of further example , whilst the above description in relation to the Figures focuses dynamically charging electric-powered mining vehicles , specifically electric-powered haul vehicles , as they move up declines and/or along drives in production levels of underground mines , the invention is not limited to these embodiments and extends to locating a dynamic electrical energy transfer assembly in other sections of an underground mine .