| 摘要 |
The invention relates to a method for recovering nickel and cobalt from laterite. According to the method, the laterite is treated with a two-step atmospheric process by employing concentrated sulphuric acid and sulphur dioxide as reagents. Metals contained by the laterite, such as iron, nickel, cobalt, magnesium, manganese and aluminium, are sulphated far and a slurry consisting of a sulphate liquid phase and an insoluble solid phase is formed. The liquid phase enters a further step of the process which implements the recovery of nickel and cobalt. A salt phase can be separated from the liquid phase and decomposed thermally to form sulphur dioxide. It can be conveyed to a sulphuric acid factory from which the quantities of sulphuric acid and sulphur dioxide required by the process return back to the process. Along with nickel and cobalt products, the process can also yield hematite and/or magnesium oxide created in the thermal decomposition. The magnesium oxide can also be utilised for the neutralisation requirements of the process. In many cases, the high-silicate leach residue can also be utilised. |
