Reduced intermediate product for ferro-nickel mfr. - from nickel contg., iron rich material and calcined crushed nickel magnesium silicate ore

摘要

The calcination is carried out at 500-800 degrees C and the calcined ore is slurried in water. A CO2-contg. gas is passed through the slurry (the CO2 partial press =1 atm), whereby the magnesium component is dissolved. The slurry is filtered; the filtrate is heated to ppte. MgCO3, which is subsequently decomposed to MgO and CO2. - The SiO2- rich residue contg. some nickel is mixed with the NiO-contg. iron-rich material, and the mixt. is heated in a CO/CO2-contg. atmos. (CO/CO+CO2=1-90%) to produce fayalite and a fayalite-forsterite solid soln. - The intermediate product obtained in this way is esp. suitable for selective reduction of NiO, because fayalite is highly resistant to reduction. Therefore, the reduction yields a Ni-rich ferronickel. The use of a nickel magnesium silicate ore increases the nickel content of the product.