Skorpion Mine, Namibia Africa

Skorpion Location Map Click on thumbnail to view larger image

Skorpion is operated by Skorpion Zinc and owned by Anglo Base Metals. Skorpion is located in Namibia, Africa, near the west coast and about 40 kilometers (km) north of the Orange River, the border between Namibia and South Africa.

History

Anglo American of South Africa discovered the Skorpion deposit. Reunion Mining plc of London, England earned a 60% interest in Skorpion by the completion of a bankable feasibility study in November 1998. In April 1999 Anglo American purchased Reunion Mining plc, reacquiring total ownership of Skorpion. Anglo then completed their feasibility study and started construction in May 2001.

Skorpion September 26, 2001 (Click on thumbnail to view larger image)

Skorpion Skorpion July 29, 2002

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Project Description

The Skorpion Mine is an oxide zinc deposit; the ore minerals are hemimorphite, smithsonite, sauconite and hydrozincite. Prior to the development of a zinc solvent extraction reagent these minerals could not be economically processed. Skorpion is the first production test of the zinc Solvent Extraction Electrowinning (SXEW) process. The SXEW process has been used for the production of copper for 30 years. The SXEW process reduces the cost of producing zinc and copper by about 30% compared to the smelter process. Essentially all zinc and 80% of copper production is produced by the smelter process.

Skorpion ore reserves are 21.4 million metric tons (mt) with a diluted grade of 11% zinc contained in 140 million mt of ore and waste. The ore will be mined by the open pit method, the pit dimensions are 800 meters x 1000 meters x 240 meters deep with a stripping ratio of ore: waste of 1: 6.5. The mine will have a 15 year mine life and produce 150,000 mt of refined zinc metal per year (SHG, 99.995% zinc).
The ore host rock is metamorphosed and folded arkose. The arkose is interbedded with tuff and is underlain by limestone. The limestone is not mineralized.

Pit North-South Section

(Click on thumbnail to view larger image) Blue - Limestone Purple - Mineralized zone at 1% cut-off grade Grey - Arkose Green - Tuff

Sulfuric acid for leaching and extraction of the zinc ore is produced from an on site acid plant by oxidizing native sulfur. Native sulfur is imported to the port of Luderitz and trucked about 400 kilometers to Skorpion.

The ore is crushed and ground, then transported to leach tanks where it is mixed with a weak sulfuric acid solution, which dissolves zinc and other soluble metals. The material is then filtered separating the solids from the metal bearing solution, the leach solution. The leach solution is mixed with an organic extraction solution, which selectively removes and concentrates zinc from the leach solution into the organic extraction solution. The spent leach solution is recycled back to the leach circuit. The organic extraction solution is then mixed with a strong sulfuric acid electrolyte solution, which removes the zinc from the organic extraction solution. The spent organic extraction solution is recycled back to the extraction circuit. The electrolyte solution is taken to electrolytic cells and the zinc reduced to SHG zinc, which is melted and poured into zinc ingots. The ingots are shipped to a warehouse at Luderitz and then shipped to LME warehouses and sold into the zinc market.