Overview

Deposit type

• Porphyry

Summary:

Copper mineralisation at Aktogay consists predominantly of chalcopyrite and occurs in quartz-carbonate filled stockwork fractures and as disseminations. It forms a compact body shaped like a flattened goblet within the rocks of the first intrusive phase and the volcanogenic sedimentary rocks of the Keregetas formation. The copper mineralisation is spatially associated with small stocks and dykes of porphyritic granodiorites and later granodiorite porphyries.

The deposition of copper and associated minerals was structurally controlled by faulting. About 70% of the copper-molybdenum mineralisation is hosted by intrusive rocks, mainly diorites and granodiorites, and about 30% by volcanogenic-sedimentary rocks of the Keregetas Formation.

The stockwork and disseminated copper mineralisation with average grade in excess of 0.2% Cu was delineated by trenching and drilling over an area of 2.1 km by 1.6 km and to a depth of 600 m to 860 m. The vertical extent of the mineralisation at a 0.15% threshold is at least 1,000 m. The copper mineralisation is accompanied by molybdenite and low but recoverable quantities of gold, silver, rhenium and selenium.

The thickness of the oxide capping is variable, the average being 18 m and maximum about 60 m. There is a general tendency for the oxide capping to thicken eastwards. The base of oxidation was defined visually during core logging. In some drillholes it was also defined by a phase analysis. The visually determined base is on average 1.8 m lower than the base defined from a phase analysis.

The oxide zone passes downwards into a weak supergene sulphide enrichment zone. Secondary copper sulphide minerals – bornite, chalcocite and covelline – are accompanied by chalcopyrite and other primary copper and by some cuprite and native copper.

Mining Methods

• Truck & Shovel / Loader

Summary:

Aktogay is a large scale, open pit mine with a remaining mine life of around 25 years (including the expansion project) at an average copper grade of 0.35% (oxide) and 0.33% (sulphide).

Comminution

Crushers and Mills

Summary:

The Aktogay 1 sulphide concentrator operates with the grinding circuit treating around 70,000 t/d (as designed) and comprises a primary 63” x 114” TS Fuller Traylor Gyratory crusher, a primary 40 ft diameter x 26 ft long FLS SAG mill with two secondary 28 ft diameter x 44 ft long FLS Ball mills, High Pressure Grinding Rolls (HPGR), and two XL1100 Raptor pebble crushers. The entire grinding circuit is closed with hydro cyclones with the coarse underflow recirculated back into the grinding circuit and the finer overflow reporting to the flotation circuit giving a product with P80 of 180 µm.

The Aktogay 40 ft FLS manufactured SAG mill has a variable speed drive (VSD) ring motor with a total installed power of 28 megawatts (MW).

In February 2013, Xstrata Technology’s IsaMill™ was selected by leading international natural resources group Kazakhmys for copper regrind applications at its Aktogay and Bozshakol projects in Kazakhstan.

"Bozshakol and Aktogay will install complete IsaMill™ Packages. Each package will include two, 3 MW, M10,000 IsaMills™, feed and discharge pumpboxes, pumps, pipework, control system, steel work, Xstrata Technology’s proprietary IsaCharger™ media addition system, and commissioning support."

The Aktogay 2 sulphide concentrator

Ore processing technology includes the following operations:
- primary crushing of ore to a particle size of 300 mm;
- semi-autogenous grinding (SAG) of ore;
- screening of SAG product;
- two-stage crushing of ore pebbles;
- the 2nd stage of ore grinding in a closed cycle with hydrocyclones;
- regrinding of the concentrate of the bulk rougher floatation in a closed cycle with hydrocyclones;
- regrinding of the concentrate of the 1st scavenger bulk floatation in a closed cycle with hydrocyclones.

Process Description

Ore from the mine pit is transported by trucks into the coarse ore hopper. The crushed ore is fed by a plate feeder from the crusher to a conveyor belt, through which it enters the main conveyor.

The units for loading the ore into the crusher and overloading from the transfer conveyor to the main conveyor are equipped with shelters with dust removal by means of a bag dust collector (ASP-1 MODEL CE8-120-3 aspiration system (3120-DC-133 PRIMARY CRUSHER DUST COLLECTOR), with 99.9% cleaning efficiency.

A self-cleaning magnet located above the discharge chute of the transfer conveyor serves to remove metallic inclusions and then transfer them to the receiving hopper of metallic impurities.

The ore after coarse crushing by the main conveyor is fed from the ore crushing complex to the coarse-ore storage area, where it is stored as a stockpile. Aspiration suction pumps are installed on all dusting points of the overfilling - ASP, (aspiration system MODEL CE8-185-3 (3230-DC-101 RECLAIM DUST COLLECTOR), MODEL IN-V36 SHRL (3560-DC-134 MOLYBDENUM CONCENTRATE BAGGING STATION DUST COLLECTOR), cleaning efficiency of 99.9%.

The system of three belt feeders and a belt conveyor supplies the ore from the stockpile to the grinding area of the main building to the SAG (semi-autogenous grinding) mill.

The balls for SAG mill are also supplied to this belt conveyor. Balls with a diameter of 125 mm are transported by road to the ball hopper, from where they are unloaded using a ball feeder to the conveyor belt. To create sanitary conditions at workplaces, a system of aspiration of dusty air with the release of cleaned air into the atmosphere is provided in a conveyor tunnel under the stack. Aspiration suction pumps are installed on all dusting points of the overfilling - ASP-2, (aspiration system MODEL CE8-120-3 (3340-DC-103 PEBBLE CRUSHING DUST COLLECTOR), MODEL IN-V36 BFRL (3882-DC-113 SODIUM HYDROSULPHIDE DUST COLLECTOR)) with cleaning efficiency of 99.9%. Dust collected in the apparatus as it accumulates is discharged onto a belt conveyor and returns to the process.

After SAG mill, the ore is screened to remove the ore of critical size. The oversize product (the ore pebble) is conveyed by the conveyor system to the ore pebble crusher, where it undergoes two crushing stages on the cone and rolling crushers, then is conveyed back to the SAG mill. The undersize product is transported to the grinding stage II to two ball mills that operate in a closed cycle with a battery of hydrocyclones.

Balls with a diameter of 80 mm from the ball hopper are unloaded by the ball feeder to the conveyor and fed into the mill of the grinding stage II. Aspiration suction pumps are installed on all dusting points of the overfilling, ASP, (aspiration system MODEL CE8-185-3 (3340-DC-104 HPGR DUST COLLECTOR), MODEL IN-V36 BFRL (3831-DC-110 SIBX DUST COLLECTOR), cleaning efficiency 99,9%.

Equipment for coarse ore crushing
For coarse crushing of ore on the open-pit side was designed a cone crusher of coarse crushing with a cone diameter of 2260 mm (89") and a receiving opening of 1600 mm (63").

Manufacturers of semi-mobile crushing plants: ThyssenKrupp Polysius, Germany; Tevona TAKRAF, Germany.

Equipment for crushing ore pebbles
For the crushing of ore pebbles, a cone crusher for stage I and a high-pressure roller crusher (press) for crushing stage II were designed.

Manufacturers of cone crushers: Sandvik, Sweden; Metso Minerals, Sweden; Thyssen Krupp Fordertechnik, Germany.

Manufacturers of high-pressure roller crushers (presses): Mashinenfabrik Koppern GmbH & Co. KG, Germany; Humboldt Wedag, Germany.

Grinding equipment
For the grinding stage I, a semi-self-grinding mill with a drum diameter of 12,2 m and a drum of 7.6 m in length was designed. For the grinding stage II, the ball mills with a drum diameter of 8,5 m and a drum length of 13,6 m were designed. To regrind the concentrate of the rough (main) bulk flotation and concentrate of the scavenger (control) bulk flotation, the multi-chamber mills with a fixed drum are recommended. The ceramic balls are used as grinding units in grinding mills.

Manufacturers: Metso minerals, Sweden; Outotes, Finland; Sandvik, Sweden; Thyssen Krupp Fordertechnik, Germany; NPO “Rivs”, St. Petersburg.

Processing

• Crush & Screen plant
• Sulfuric acid (reagent)
• Flotation
• Heap leach
• Dewatering
• Filter press
• Solvent Extraction & Electrowinning

Summary:

The Aktogay open pit, sulphide concentrator and oxide plant located in the east of Kazakhstan.

The sulphide concentrator was commissioned in the final quarter of 2016. The capacity of the existing concentrating plant for processing sulfide copper-molybdenum ores is 25.0 million tons of ore per year.

The smaller oxide plant was commissioned in the fourth quarter of 2015 and produces copper cathode. The oxide plant is included in the Aktogay operating segment due to the sharing of infrastructure, its relatively small size and to reflect the Group’s management structure.

An expansion of the sulphide processing facilities at Aktogay was announced in December 2017. The expansion project envisages an increase in processing up from 25 to 50 million tons per year.

Copper cathode production from oxide ore at Aktogay will be unchanged at the current level of around 20,000 t/y for the remaining eight year life of the oxide deposit.

The Aktogay expansion project to double sulphide processing capacity at the mine was officially opened in October 2021, with first shipments to customers dispatched in December 2021.

Ore processing technology includes the following operations:
- the rougher, scavenger and three recleaner operations of bulk floatation;
- thickening of the bulk concentrate;
- two stages of slurry (pulp) agitation of the bulk concentrate;
- roughing and 4 recleaner operations of molybdenum floatation;
- thickening and filtration of molybdenum and copper concentrates;
- thickening of tailings.

The flow process involves the use of the following reagents:
- lime;
- Sodium isobutyl xanthate;
- methylisobutylcarbinol;
- sodium sulfide and sodium hydrosulfide;
- pine oil;
- molybden collector;
- flocculant.

The concentration under the said flowsheet of the original ore with a copper and molybdenum content of 0,361% and 0,009%, respectively, allows the following technological parameters to be achieved:
- copper content in copper concentrate 24,3%;
- content of molybdenum in molybdenum concentrate is 46,3%;
- extraction of copper into copper concentrate 83,8%;
- extraction of molybdenum into molybdenum concentrate 75,0%;
- content of copper in the tailings 0,059%;
- content of molybdenum in the tailings of 0,002%.

Process Description

The hydrocyclone overflow of the grinding stage II enters the chambers of floatation machines of the rougher bulk floatation. The concentrate of the rougher bulk floatation enters the regrinding mill operating in a closed cycle with a battery of hydrocyclones. The hydrocyclone overflow goes through the 2nd recleaner.

The tailings of the bulk rougher flotation enter the chambers of flotation machines of the scavenger bulk floatation. The concentrate of the scavenger bulk floatation is re-grinded in a mill operating in a closed cycle with hydrocyclones. The hydrocyclone overflow enters the cells of flotation machines of the scavenger bulk flotation I, the concentrate of which is sent to recleaner III.

Tailings of the recleaner I are sent to the control recleaner flotation, the concentrate of which is returned to the cycle of the re-grinding cycle of the concentrate of control flotation.

Concentrate of the recleaners II and III, which is a bulk copper-molybdenum concentrate, is condensed in a thickener to remove the parts of the reagents with an overflow, which is returned to the process as recycled water.

The thickened bulk concentrate is agitated with sodium hydrosulfide in a mixture with sodium sulfide in two agitators and enters the flotation machine of the rougher molybdenum flotation. The concentrate of the rougher molybdenum flotation is subjected to recleaner I. The froth product of the sixth molybdenum recleaner enters the molybdenum regrinding mill, working in a closed cycle with a battery of hydrocyclones. The hydrocyclone overflow is sent to the II clean-up molybdenum flotation, the tailings of which are returned to the molybdenum recleaner- I. And the concentrate is subjected to two consecutive recleaners. The froth product of the fourth molybdenum recleaner is a finished molybdenum concentrate. The flotation product of the rougher molybdenum flotation is a finished copper concentrate.

Molybdenum and copper concentrates are thickened in their respective thickeners, the overflows of which are returned to the process as recycled water. The thickened products are sent to the appropriate press filters of the filter area with a warehouse of concentrates.

Copper concentrate after filtration on two parallel operating filter presses is stored in stockpiles. The copper concentrate from the warehouse is shipped by the loader to the railway cars.

The molybdenum concentrate after filtration on a filter press is packed in big bags and sent to consumers.

Tailings of the scavenger bulk and recleaner flotations are the waste tailings, which by gravity are transported to the tailings sump and then pumped to the tailings thickeners. The thickened tailings are pumped to the tailings pond (under the project of the second phase of construction of he tailings storage).

Processing of ores is envisaged under the scheme of circulating water supply. Thickener drains are returned to the process as recycled water.

Filter press
The Larox® PF plate pack expansion increased concentrate production by 25% at KAZ Minerals’ Aktogay Concentrator Plant in Kazakhstan. The PF expansion is a cost-efficient way to rapidly increase filter capacity, increase production and gain maximum benefit from your current filtration equipment.

KAZ Minerals planned to increase copper concentrate production at its greenfield project Aktogay plant by increasing the filtration capacity by 25%.

The solution avoided large investment costs by avoiding having to purchase additional filters to expand the capacity of the existing filtration area. Both filters were expanded from 72 m2 up to 96 m2 by installing 4 additional plates to each filter.

Pipelines and Water Supply

Summary:

The source of water supply is the Zhuzagash groundwater field, located 30 km west of the Aktogay field in the valley of the Ayagoz River.

The water supply from the pumping station to the Aktogay site will be carried out through a pipeline with a diameter of 900 mm and a length of 30 km, laid below the freezing depth at a depth of 2.8 m. This pipeline will supply water to the process water pond and raw water tank at the mine site.

The supply of crude (raw) water to consumers for the period of operation is as follows: from the Zhuzagash groundwater field, crude (raw) water is pumped through a pressure conduit with a diameter of 900 mm to the industrial site of the Sulpide Concentrator to a crude (raw) water tank with a capacity of 1500 m3.

Overflow of water from the crude (raw) water tank is delieverd into the pond of technical water with a lining of high density polyethylene with a volume of 56,000 m3, which serves as a reservoir of the circulating water of the Sulphide Concentrator, to compensate for the loss of water absorbed by the tailings pulp (feeding of the processing system of the concentrator).

The rest of the water from the crude (raw) water tank is delievered by pumps (1 operating, 1 reserve) of the raw water pumping station to the processing needs of the Sulphide Concentrator, to prepare reagents and milk of lime, to the reverse osmosis plant, to the fire extinguishing system, to feed the circulating system of the compressor station, to dust suppression, to the chlorination unit.

The need for crude (raw) water for the production needs of the factory is: 73512.92 m3 / day, including raw water - 61528,89 m3 / day.

It is supplied by the projected intake of Zhuzagash field of underground water of the drinking quality. The water intake is located 30 km west of the Aktogay field in the valley of the Ayagoz river (Zhuzagash field of groundwater).

Aktogay mine is supplied with groundwater via boreholes. Concentrator recycles 70-80% of process water.

Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
Concentrator Manager	Aizharyk Berdaliyev		Mar 3, 2024
General Director	Tony Todd		Mar 3, 2024
Maintenance Manager	Anton Khoroshev		Mar 3, 2024
Maintenance Manager	Yegor Melnichenko		Mar 3, 2024
Maintenance Planner	Baurzhan Dyussembekov		Mar 3, 2024
Maintenance Planning Superintendent	Timur Kabdushev		Mar 3, 2024
Project Director	Andrew Batteson		Mar 3, 2024
Technical Director	Johan Barnard		Mar 3, 2024
Technical Services Manager	Emmanuel Obeng		Mar 3, 2024