Nkk Corporation

Chihiro Taki

Katsuhiro Iwasaki

Haruyoshi Tanabe

Masahiro Kawakami

Toshio Takaoka

A method for smelting reduction of Ni ore comprises charging Ni ore and carbonaceous material into a converter type smelting reduction furnace having bottom-blow tuyeres and a top-blow lance, the smelting reduction furnace holding a molten metal, blowing oxygen gas from the top-blow lance and a stirring gas from the bottom-blow tuyeres into the furnace, and discharging slag so that a relation represented with a formula

Method for smelting reduction of Ni ore

A method for manufacturing molten metal containing Ni and Cr comprises a process of smelting and reducing Ni ore, and a process of smelting and reducing Cr ore. The process of smelting and reducing Ni ore comprises the steps of charging molten iron into a smelting reduction furnace having a top-blow oxygen lance and tuyeres for blowing stirring gas, charging Ni ore, carbonaceous material and flux into the smelting reduction furnace, blowing decarbonization oxygen and post-combustion oxygen from the top-blow oxygen lance into the smelting reduction furnace, blowing stirring gas for stirring the molten metal and slag inside the smelting reduction furnace from the tuyeres, and controlling post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] at 0.3 or more. The process of smelting and reducing said Cr ore comprises charging Cr ore, carbonaceous material and flux into the smelting reduction furnace holding the molten metal containing Ni, blowing decarbonization oxygen and post-combustion oxygen from the top-blow oxygen lance into the smelting reduction furnace, blowing stirring gas for stirring the molten metal and slag inside the smelting reduction furnace from the tuyeres, and controlling post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] at 0.3 or more.

Method for manufacturing molten metal containing Ni and Cr

A method for smelting reduction of Ni ore comprises charging Ni ore, carbonaceous material and flux into a converter type smelting reduction furnace holding molten iron therein and controlling a post-combustion ratio [(H.sub.2 O+CO.sub.2)/(H.sub.2 +H.sub.2 O+CO+CO.sub.2)] inside the smelting reduction furnace at 0.3 or more by blowing oxygen from a top-blow oxygen lance and stirring gas from a bottom-blow tuyere arranged in the bottom of the smelting reduction furnace into the smelting reduction furnace. A relation between a content of carbon [C] (%) in molten metal and an amount of slag produced per ton of molten metal is represented with a formula:

Growing community of inventors

Tokyo, Japan

Chihiro Taki