Laboratory Column Leaching of Cobalt using Raffinate and Sodium Metabisulfite

In the Democratic Republic of the Congo, minerals containing trivalent cobalt exhibit poor leaching characteristics in sulfuric acid without the aid of reducing agents such as sodium metabisulfite. This study aimed to evaluate the effectiveness of sodium metabisulfite to enhance laboratory column leaching efficiency for extracting cobalt from low-grade copper ore. The methodology involved utilizing low-grade raffinate from copper cathode production as a leaching solution, thereby reducing neutralization costs while simultaneously increasing the output of both copper and cobalt. Laboratory tests were conducted to quantify the leaching performance and to assess the potential for practical implementation in processing plants. Results indicated that employing low-grade raffinate not only improved cobalt recovery rates but also presented economic advantages by minimizing processing costs associated with acid neutralization in the cobalt plant. The findings suggest that the application of sodium metabisulfite in conjunction with low-grade raffinate could be a viable strategy for optimizing cobalt extraction in the region's mining sector, marking a significant innovation in the treatment of low-grade copper-cobalt ores.