摘要:
An object of the present invention is to provide a method for reducing a chromium-containing material at a high chromium reduction degree. In the method of the present invention, a mixture of a feedstock containing chromium oxide and a carbonaceous reductant is heated and reduced by radiation heating in a moving hearth furnace. The average rate of raising the temperature of the mixture in the reduction is preferably 13.6° C./s or higher in the period from the initiation of the radiation heating of the mixture until the mixture reaches 1,114° C.
摘要:
An object of the present invention is to provide a method for reducing a chromium-containing material at a high chromium reduction degree. In the method of the present invention, a mixture of a feedstock containing chromium oxide and a carbonaceous reductant is heated and reduced by radiation heating in a moving hearth furnace. The average rate of raising the temperature of the mixture in the reduction is preferably 13.96° C./s or higher in the period from the initiation of the radiation heating of the mixture until the mixture reaches 1,114° C.
摘要:
The present invention provides a method for efficiently manufacturing a titanium oxide-containing slag from a material including titanium oxide and iron oxide, wherein a reduction of titanium dioxide is suppressed and the electric power consumption is minimized. The method includes the steps of: heating a raw material mixture including titanium oxide, iron oxide, and a carbonaceous reductant, or the raw material mixture further including a calcium oxide source, in a reducing furnace; reducing the iron oxide in the mixture to form reduced iron; feeding the resultant mixture to a heating melting furnace; heating the resultant mixture in the heating melting furnace to melt the reduced iron and separate the reduced iron from a titanium oxide-containing slag; and discharging and recovering the titanium oxide-containing slag out of the furnace.
摘要:
An object of the present invention is to provide a method for reducing a chromium-containing material at a high chromium reduction degree. In the method of the present invention, a mixture of a feedstock containing chromium oxide and a carbonaceous reductant is heated and reduced by radiation heating in a moving hearth furnace. The average rate of raising the temperature of the mixture in the reduction is preferably 13.96° C./s or higher in the period from the initiation of the radiation heating of the mixture until the mixture reaches 1,114° C.
摘要:
The present invention provides a method for efficiently manufacturing a titanium oxide-containing slag from a material including titanium oxide and iron oxide, wherein a reduction of titanium dioxide is suppressed and the electric power consumption is minimized. The method includes the steps of: heating a raw material mixture including titanium oxide, iron oxide, and a carbonaceous reductant, or the raw material mixture further including a calcium oxide source, in a reducing furnace; reducing the iron oxide in the mixture to form reduced iron; feeding the resultant mixture to a heating melting furnace; heating the resultant mixture in the heating melting furnace to melt the reduced iron and separate the reduced iron from a titanium oxide-containing slag; and discharging and recovering the titanium oxide-containing slag out of the furnace.
摘要:
The present invention provides a process that is useful in producing ferronickel having a high Ni content at low cost with high efficiency and reproducibility even if a low-grade feedstock containing nickel oxide is used. In particular, a feedstock containing nickel oxide and iron oxide is mixed with a carbonaceous reductant, the mixture is formed into agglomerates with an agglomerator, and the agglomerates are heated and reduced in a moving hearth furnace, whereby reduced agglomerates in which the Ni metallization degree is 40% or more and the Fe metallization degree is at least 15% less than the Ni metallization degree are prepared by adjusting the retention time of the agglomerates placed in the moving hearth furnace. The reduced agglomerates, in which the Ni component has been primarily reduced as compared with the Fe component, are smelted in a smelting furnace, whereby ferronickel having a high Ni content is obtained.
摘要:
The present invention provides a process that is useful in producing ferronickel having a high Ni content at low cost with high efficiency and reproducibility even if a low-grade feedstock containing nickel oxide is used. In particular, a feedstock containing nickel oxide and iron oxide is mixed with a carbonaceous reductant, the mixture is formed into agglomerates with an agglomerator, and the agglomerates are heated and reduced in a moving hearth furnace, whereby reduced agglomerates in which the Ni metallization degree is 40% or more and the Fe metallization degree is at least 15% less than the Ni metallization degree are prepared by adjusting the retention time of the agglomerates placed in the moving hearth furnace. The reduced agglomerates, in which the Ni component has been primarily reduced as compared with the Fe component, are smelted in a smelting furnace, whereby ferronickel having a high Ni content is obtained.
摘要:
The present invention provides a method for efficiently manufacturing a titanium oxide-containing slag from a material including titanium oxide and iron oxide, wherein a reduction of titanium dioxide is suppressed and the electric power consumption is minimized. The method includes the steps of: heating a raw material mixture including titanium oxide, iron oxide, and a carbonaceous reductant, or the raw material mixture further including a calcium oxide source, in a reducing furnace; reducing the iron oxide in the mixture to form reduced iron; feeding the resultant mixture to a heating melting furnace; heating the resultant mixture in the heating melting furnace to melt the reduced iron and separate the reduced iron from a titanium oxide-containing slag; and discharging and recovering the titanium oxide-containing slag out of the furnace.
摘要:
A method for making molten iron includes the steps of feeding a raw material mixture containing an iron oxide material and a carbonaceous reductant into a heating reduction furnace to reduce iron oxide in the raw material mixture with the carbonaceous reductant into solid reduced iron; transporting the solid reduced iron to a melting furnace; and combustion of a carbonaceous material supplied as fuel to melt the solid reduced iron in the melting furnace for producing molten iron. After the metallization of the solid reduced iron is enhanced to at least 60%, the solid reduced iron is transported to the melting furnace. The amounts of oxygen and the carbonaceous material supplied to the melting furnace are controlled so that the secondary combustion ratio of CO gas in the melting furnace is reduced to 40% or less. The heat transfer efficiency of the secondary combustion heat to the molten iron is preferably increased to at least 60%.
摘要:
A method for manufacturing a reduced metal includes thermally reducing a metal oxide including a carbonaceous reductant disposed on a hearth moving in a reducing furnace, wherein the reducing furnace includes a plurality of primary burners for supplying fuel and primary combustion air, and a plurality of secondary combustion burners for supplying secondary combustion air; and wherein the primary combustion air and/or the secondary combustion air is oxygen-enriched air, the oxygen concentration in the primary combustion air supplied from at least one of the plurality of primary burners being controlled to be lower than the oxygen concentration in the secondary combustion air.