Method for smelting schreyerite in coke oven gas-based shaft furnace-electric furnace melt separation deep reduction

Abstract

The invention belongs to the field of comprehensive utilization of schreyerite, and particularly relates to a method for smelting schreyerite in a coke oven gas-based shaft furnace and smelting deep reduction in an electric furnace, in particular to a method for smelting schreyerite in a coke oven gas-based shaft furnace and smelting deep reduction in an electric furnace. The vanadium-titanium pellets are reduced in the gas-based shaft furnace, and vanadium-titanium direct reduction iron is obtained; the vanadium-titanium direct reduction iron is subjected to melting reduction in an electric furnace to obtain vanadium-containing molten iron and titanium slag, the gas-based shaft furnace at least uses one coke oven gas as a gas source, and purified gas at the top of the gas-based shaft furnace exchanges heat with hot gas in a gas ascending pipe of the coke oven and then is mixed into high-temperature reducing gas generated by the coke oven gas to form furnace-entering reducing gas of the gas-based shaft furnace; and reducing gas is blown into the molten layer in the electric furnace, the reducing gas reacts with the vanadium and iron oxides to generate vanadium and iron metal liquid and titanium slag, and the vanadium and iron metal liquid enters the molten iron. Electric furnace smelting power consumption can be reduced, the influence of newly added materials of the electric furnace on the titanium slag grade is reduced, and efficient and reasonable utilization of different types of heat energy is achieved.

Description

technical field [0001] The invention belongs to the field of comprehensive utilization of vanadium-titanium ore, and in particular relates to a method for smelting vanadium-titanium ore by coke oven gas gas-based shaft furnace-electric furnace fusion and deep reduction. Background technique [0002] The reserves of vanadium titanomagnetite resources in my country are huge, and the overall development and utilization is mainly based on blast furnace processes, and the output of non-blast furnace methods is relatively low. The overall recovery rate of titanium and vanadium is not high, and the waste of resources is relatively serious. In the prior art, the non-blast furnace method is superior to the blast furnace method, which can realize all-vanadium-titanium smelting, and the recovery rate of iron, vanadium and titanium is relatively high. The non-blast furnace smelting method adopts the pre-reduction (rotary kiln, rotary hearth furnace, gas-based shaft furnace)-electric fu...

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that by burning fuel to heat the raw gas, it will emit CO 2 and other exhaust gases, and the tubular heating furnace has a large investment; for this problem, some solutions have been proposed in the prior art, such as the application number CN201280023094.3, which is called using coke oven gas and oxygen steelmaking furnace gas to reduce iron oxide to Systems and methods for metallic iron, addressing "minimization of equipment and thus plant cost by eliminating external catalytic reformers"

However, the patented technology is still partly heated by a tubular heating furnace, so there is still emission of CO 2 and other waste gas problems, as well as high investment in equipment

Another example is the application number CN202010762774.3, which is called a method for distributed utilization of heat in the process of producing direct reduced iron in a CDQ coupling shaft furnace. Heat exchange in the heater, this patent uses inert gas as the sensible heat of red coke and the thermal energy conversion medium of cold reducing gas, replacing the fuel part of the raw material gas in the existing process to provide heat for the system, although this can solve the emission CO 2 and other exhaust gas problems, but there are still the following problems: the heat exchange between red coke and cold reducing gas is realized through the inert gas as the heat energy conversion medium, and the inert gas loses energy during the two heat energy conversion processes, and the heat exchange efficiency is low; Increase the investment and operating cost of inert gas manufacturing; increase the power system and dust removal system for inert gas circulation; increase the air distribution system for safety assurance; moderately increase the CO content in the reducing gas by adjusting the carbon-hydrogen ratio in the reducing gas to reduce the consumption of reducing gas This is a known technology; but the shaft furnace top gas (top gas) is all recycled as reducing gas, which will cause the enrichment of inert gas in the top gas, affecting production efficiency and normal operation of production

Among them, the electric furnace deep reduction of the patent CN201910859500.3 is to put the vanadium-titanium magnetite pre-reduction pellets into the electric furnace for deep reduction, add flux and carbon, and the melting temperature is 1550-1650 ℃, and separate the vanadium-containing molten iron and titanium-containing Slag; the metallized pellet electric furnace melting of the patent CN201310372684.3 is to put metallized pellets into the melting electric furnace, the melting temperature is 1600-1700°C, the carbon content is 2-6%, the slag basicity is 0.7-1.3, and the melting The time is 50-70 minutes. After the smelting is completed, the molten titanium slag is discharged through the slag outlet, and the vanadium-containing molten iron is discharged through the iron outlet. Increase power consumption and reduce the grade of titanium slag

The technical disadvantage of the above method is that with the increase in the number of slag retention, the capacity of the electric furnace decreases gradually, and the output of molten iron in a single furnace gradually decreases; the electric furnace is divided into an electric arc furnace and a submerged arc furnace. Unreasonable, it will generate extremely high power consumption

Images