Method for producing high-purity metal chromium by using carbon reduction method

Abstract

The invention relates to a method for producing high-purity metal chromium by using a carbon reduction method. The method comprises the following steps of: uniformly mixing chromic oxide powder and carbon black powder, adding deionized water or alcohol to form a wet mixed material, carrying out press forming, and drying, thereby obtaining a mixed material block; putting the mixed material block in a vacuum furnace, and enabling chromic oxide to be reduced by carbon black under high-temperature vacuum conditions, thereby obtaining crude chromium; introducing gaseous carbon monoxide, and carrying out heat preservation for 3-8 hours at the temperature of 1,300-1,500 DEG C; introducing gaseous carbon dioxide, and carrying out heat preservation for 3-8 hours at the temperature of 800-1,000 DEG C; and cooling down, and discharging, thereby obtaining a high-purity metal chromium block. According to the method, a gas-solid reduction manner is adopted to remove residual raw materials and non-metallic impurities, so that the production cost is reduced, and the reduction time is shortened; and the produced high-purity metal chromium has the purity of 99.96-99.98%, the oxygen content less than 0.03%, the sulfur content less than 0.01% and the carbon content less than 0.01%, thereby meeting the standards of the high-purity metal chromium.

Description

technical field [0001] The invention relates to a method for producing high-purity metal chromium, in particular to a method for producing high-purity metal chromium by carbon reduction. Background technique [0002] Metal chromium is widely used in glass coating, steel alloy, coating target, aerospace materials, steam turbines and other fields. Especially in the application of coating targets, aerospace materials and steam turbines, the purity requirements for metallic chromium are very high, and generally high-purity chromium with a purity of more than 99.9% is required. [0003] The main methods for industrial production of high-purity chromium are electrolysis, aluminothermic reduction and carbon reduction. The purity of metal chromium produced by electrolysis and aluminothermic reduction is limited, and generally can only reach 99.0% to 99.7%. It needs to be purified again to prepare high-purity metal chromium (purity is more than 99.9%, and the content of oxygen, ca...

AI Technical Summary

Problems solved by technology

Its disadvantages are: complex production process, insufficient purity of raw materials, use of binders or grinding to cause pollution to products, purity of metal chromium is lower than 99.85%, high content of non-metallic impurities such as oxygen, carbon and sulfur, oxygen content > 0.1%, carbon Content > 0.008%, sulfur content > 0.01%, cannot meet the requirements of high-purity metal chromium, and the product quality is unstable

The metal chromium C content and S content that this method handles are all lower, and S content<10ppmw, C content<30ppmw; Long reaction time, large hydrogen flow rate, high production cost