Influence of Metallic Impurities on Solvent Extraction of Cobalt and Nickel from a Laterite Waste Liquor

摘要

Limonite is the surface zone of lateritic ore and it was considered an ore waste. However, because of the demand, limonite is now considered an important resource of nickel and cobalt. The presence of impurities in the ore such as magnesium, manganese, and chromium makes it difficult for the recovery of nickel and cobalt. The separation of nickel and cobalt can be done by solvent extraction technique using Cyanex 272 as the extractant. In order to study the extraction of cobalt and nickel from a solution containing chromium, magnesium, and manganese, the pH range between 3.5 and 5.5 was investigated. However, precipitation of chromium, magnesium, manganese, and nickel was observed at pH 5.5. By increasing the pH value, the extraction of cobalt, magnesium, manganese, and chromium was increased. Nickel was not extracted during the study. It was not possible to obtain a solution containing only nickel or cobalt without the presence of the other metals in solution.