• 1
  • 2
  • 3

Cloncurry

CopperChem’s resources are centered around its hydrometallurgical and copper concentrator production facilities, adjacent to the Cloncurry township. CopperChem resources delineated for the project to date total 5.89Mt @ 0.94% Cu and 0.12g/t Au containing 55,000t Copper and 22,700oz Gold.

Reserves & Resources, May 2013*

Reserves

Resources

Tonnes

Copper (Cu) %

Gold (Au) grams/tonne

Tonnes

Copper (Cu) %

Gold (Au) grams/tonne

GAM

60,000

1.4

0.1

3,000,000

1.06

0.08

Orphan Shear

284,000

0.93

0.03

241,000

1.00

0.03

Taipan

72,000

1.51

0.11

2,220,000

0.74

0.11

Notlor

426,000

1.04

0.52

426,000

1.04

0.52

TOTAL

842,000

1.07

0.29

5,887,000

0.94

0.12

*Non-JORC figures; resources are exclusive of reserves


Processing

Processing of ores at CopperChem's Cloncurry site is achieved in two ways: flotation of the copper sulphides ores and heap leaching of the copper oxide ores.

Ore from the operating mines is trucked to a ROM stockpile where it is classified as copper oxide, transitional (containing predominantly chalcocite copper), high grade sulphide or low grade sulphide.

The first step of actual processing is crushing. All the ores are crushed through a 260tph capacity mobile jaw crusher to a product size of under 12mm. Oxide ore reports to the oxide ROM stockpile while the sulphide ore reports to the ROM sulphide stockpile via a radial stacker. Depending on the ore sources being mined, transitional ore may be directed to either oxide or sulphide stockpiles.


Concentrator

The processing plant is capable of treating over 80tph. It consists of a closed ball milling circuit, a rougher-cleaner flotation circuit, a concentrate thickener, concentrate disk filters and a concentrate storage shed. The grinding circuit, essentially one 1,000kW ball mill, produces a flotation feed size P80 of 106 microns. The flotation circuit, which includes regrinding of the rougher concentrate before cleaning, produces a 25%Cu grade concentrate. Copper recovery of over 90% is achieved. Final concentrate is then shipped by roadtrain either to the Mt. Isa copper smelter or to port for overseas smelting.


Heap Leaching

A heap leach area of approximately 200m x 350m, divided into 6 cells with HDPE bottom lining, receives the oxide ores. The ore is stacked 4m high and includes aeration to improve extraction of transitional copper ores. Dilute acid, referred to as raffinate, is spread evenly onto the heaps with drip lines. This solution trickles through the heap of ore and dissolves the Cu from the ores into solution that is recovered as pregnant leach solution (PLS). Copper recovery from heap leaching is typically 80%.


SX Crystal Plant

Solvent Extraction (SX) selectively extracts copper from the PLS and transfers it to a pure sulphuric acid based electrolyte from which the copper can be efficiently crystallised as copper sulphate pentahydrate. The crystals are then packed into bulk bags ready for dispatch.