METHOD OF RECOVERY OF NICKEL AND COBALT FROM FERRUGINOUS LATERITE ORES

The invention relates to the field of non-ferrous metallurgy, in particular to a method for processing laterite nickel ores with recovery of nickel and cobalt. In a method involving grinding of the ore, roasting of the ore in a reducing atmosphere for selective reducing of nickel and cobalt, cooling the reduced ore in a non-oxidizing atmosphere to a temperature of 150-300°C, and leaching the cooled cinder with transfer, of nickel and cobalt to the solution, the roasting of the ore in a reducing atmosphere is carried out in the temperature range of 700- 800°C, preferably at 725-775°C, and the cooled cinder is leached with sulfuric acid in a weakly acidic medium at a pH of 1.4-3.5, preferably at a pH of 2.5-3.0, at a temperature of 30- 100°C, preferably at 85-95°C for 45-120 minutes, preferably 60-90 minutes. Before roasting, the ore is preferably mixed with a reducing agent: brown (subbituminous) coal in an amount of 3-3.5% of the weight of the ore. In addition, petroleum fuel, such as fuel oil, can be used as a reducing agent. The roasting process is carried out in the rotary kiln or in a vertical multiple- hearth furnace. For selective reduction of nickel and cobalt during roasting, a reducing atmosphere can be created by controlling the ¾ and CO content in the gas atmosphere of the furnace. Under these conditions, the degree of recovery of nickel from the ore is 88-99%, and the degree of recovery of cobalt is 73-84%. When the process is carried out in the established parameters, along with the achievement of a high degree of metal recovery, material flows in the hydrometallurgical conversion decreasing by 2-2.5 times, and the technical and economic parameters of the process as a whole are improved. L'invention concerne le domaine de la métallurgie non ferreuse, en particulier un procédé pour le traitement de minerais de nickel latéritiques avec récupération de nickel et de cobalt. Selon un procédé impliquant le broyage du minerai, le grillage du minerai dans une atmosphère réductrice pour la réduction sélective du nickel et du cobalt, le refroidissement du minerai réduit dans une atmosphère non oxydante à une température de 150 à 300 °C et la lixiviation des scories refroidies avec un transfert du nickel et du cobalt vers la solution, le grillage du minerai dans une atmosphère réductrice est effectué dans la plage de température de 700 à 800 °C, de préférence à 725 à 775 °C, et les scories refroidies sont lixiviées avec de l'acide sulfurique dans un mili