AN IMPROVED PROCESS FOR THE EXTRACTION OF NICKEL, COBALT AND IRON FROM LATERITIC NICKEL ORES.

摘要

An improved process for the extraction of nickel, cobalt and iron from the lateritic nickel ores which comprises: (a) leaching lateritic nickel are with mineral acid and traces of organic acid followed by filtration; (b) heating the filtrate obtained in step (a) to boiling, adding neutralizing agent to the boiling filtrate to separate iron as precipitate; (c) adding strong oxidizing agent to the filtrate obtained in step (b) to raise the pH of the filtrate in the range of 3 to 4, adding oxidizing acids to lower the pH below 0.7, followed by addition of neutralizing agent to the mixture to raise the pH in the range of 2.7 - 3, filtering the resultant mixture to separate cobalt as precipitate; (d) adding neutralizing agent to the filtrate obtained in step (e) till the pH is in the range of 8 to 10 followed by filtration to obtain nickel as precipitate.