Kitwe black mountain - Is Zambia realising the true value from it?

Abstract

Nkana slag dump (The Black Mountain) in Kitwe, Zambia, has existed since 1931 when the copper smelter was commissioned. This 20 million tonnes of smelter slag contains about 0.34 per cent - 4.5 per cent cobalt and average 1.2 per cent copper. When Zambia Consolidated Copper Mines Limited was privatised, the slag dump was purchased by Anglo Vaal Mining (90% shareholding) who built a smelter in Chambishi in 2000 to recover the cobalt and copper in the slag. The smelter operations closed in 2006 and the slag dump was later sold to Nkana Alloy and Smelting Company Limited. Various small scale illegal miners (locally called Jerabos) started illegally reclaiming the slag and selling to Chinese buyers operating small scale mineral processing plants. In the recent past, the government surrendered its 10 per cent shareholding of the slag dump to Chapamo Minerals Processing Company owned by the small scale local community (Jerabos). The substandard technologies being used by these small scale plants yield very low recoveries of about 50-60 per cent for both cobalt and copper, thus discarding huge quantities of valuable cobalt and copper which could be recovered if appropriate technologies were applied. This potential revenue to the nation in taxes is being lost. These small scale plants have not invested in appropriate advanced technology which can yield above 90 per cent recoveries because of their quest to make quick and easy money. The serious safety shortcomings at the slag dump have resulted in unnecessary loss of lives. The recent incident on 21 June, 2018 claimed 11 lives. There is need to study the physical structure of the slag dump to provide clear understanding of the safety precautions to be taken while reclaiming the material. There is, therefore, an opportunity to increase recoveries of the cobalt and copper by applying appropriate advanced technologies to process the slag. This will result in improved revenue, thus realizing the true value.