Direct extraction of nickel and iron from laterite ores using the carbonyl process

• Carbonyl method of extraction of Ni and Fe from laterite ore was applied to several types of ores.
• Ore reduction with hydrogen gas was compared with reduction by CO/CO2 gas mixture.
• Extraction of nickel and iron was done at elevated pressure and temperature.
• Fractional distillation of metal carbonyls allowing producing high purity of Ni and Fe products.
• PGE metals such as Au, Pt, Pd and Rh were concentrated from 2.4 g/ton to close to 30 g/ton.

The carbonyl method of refining nickel and iron was invented more than 100 years ago and has been used for refining of nickel commercially. CVMR® developed the process of direct extraction of nickel and iron from laterite ores as metal carbonyls which in turn produced pure nickel and iron metals.CVMR®’s carbonyl technology has been applied to several types of limonite and saprolite ores containing other metals such as copper, cobalt and PGE. The process consists of reducing the ore with hydrogen, extracting of iron and nickel in the form of volatile metal carbonyls, separating the metal carbonyls and producing high purity nickel and iron metals; and production of copper, cobalt and PGE concentrate by gravity or magnetic separation. Economic evaluation of this process shows significant increase in cash flow. The CVMR® process does not produce liquid waste and does not require tailing dumps. This makes CVMR®’s process attractive for projects in areas that are environmentally sensitive, or have a high level of rainfall.