Abstract
In ferrous metallurgy, nickel is an extremally important alloying element used in the production of stainless, heat-resistant, acid-resistant steels. For the development of ferronickel production in the Russian Federation, it is proposed to involve into processing complex off-balance iron-chromium-nickel ores of the Khalilovskoye deposit, which are not used at the present. In this work, the dependences of the degrees of elements reduction from ironchromium-nickel ore on the degree of extraction of iron were studied.This information is needed for the selection of the composition and development of the technology for ferronickel production. Burned ore raw materials were subjected to selective carbothermal reduction at the Slag Remelting laboratory unit. In the obtained ferronickel, the Ni content with an increase in the consumption of the reducing agent decreased from 65 to 3%, P - from 0.68 to 0.38%, S - from 0.19 to 0.10%. The nickel recovery rate at 1% iron reduction was only 50%, at 5% - 65–75%, at 20% - 95%. The content of iron oxides in the partially reduced melt with an increase in coke consumption decreased from 61 to 53%, and NiO - from 0.192 to 0.010%. Analysis of obtained dependences shows that it is not effective to recover less than 5% of iron due to the low degree of nickel recovery (less than 70%). The rational degree of iron reduction from ore raw materials is 5-10%, which corresponds to the nickel content in the finish ferroalloy Ni ~ 10-20%, phosphorus – P ~ 0.3-0.5%, sulfur – S ~ 0.08-0, 09%. Obviously, the resulting rough ferronickel needs refining, primarily dephosphorization.
Keywords: iron-chromium-nickel ore, selective reduction, nickel, ferronickel, alloying.