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

A reduction method, metal chromium technology, applied in the direction of improving process efficiency, etc., can solve the problems of failing to meet the requirements of high-purity metal chromium, unstable product quality, low metal chromium purity, etc., to shorten production time and shorten reduction reaction. Time and the effect of large specific surface area

Inactive Publication Date: 2013-03-13
JINZHOU NEWROUTE HYPERPURE MATERIAL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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 > ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] 1. Mix 100 kg of chromium trioxide powder with a purity >99.0% and an average particle size of 325 mesh and 28 kg of carbon black powder with a sulfur content of <0.01% and an average particle size of 10 μm for 2 hours to obtain a mixed powder; Add the mixed powder into deionized water in batches, each batch of mixed powder is 20kg, add 4kg of deionized water, and then stir evenly to form a mixed wet material;

[0031] 2. Press the mixed wet material through a mold with a pressure of 0.5 MPa to form a 64g / block mixed wet material block, put the mixed wet material block into an oven equipped with an infrared heating tube, and dry it at 200°C for 4 hours to obtain a mixed Block;

[0032] 3. Put the mixture block into the vacuum furnace, control the vacuum degree at 10Pa~50Pa, increase the temperature to 1400℃, and keep it warm for 2 hours; feed high-purity argon into the vacuum furnace to increase the vacuum degree to 3000Pa~5000Pa, Insulate at 1400°C for 18 hours to r...

Embodiment 2

[0037] 1. Mix 100 kg of chromium trioxide powder with a purity >99.0% and an average particle size of 625 mesh and 20 kg of carbon black powder with a sulfur content of <0.01% and an average particle size of 1 μm for 2 hours to obtain a mixed powder; Add alcohol to the mixed powder in batches, each batch of mixed powder is 20kg, add 7kg of alcohol, and then stir evenly to form a mixed wet material;

[0038] 2. Press the mixed wet material through a mold with a pressure of 0.2MPa to form a mixed wet material block of 30g / block, put the mixed wet material block into a vacuum furnace, vacuumize, and dry at 300°C for 1 hour to obtain a mixed material block ;

[0039] 3. Control the vacuum degree of the vacuum furnace at 10Pa~50Pa, increase the temperature to 1300°C, and keep it warm for 2.5h; feed high-purity argon into the vacuum furnace to raise the vacuum degree to 1000Pa~2000Pa, and keep it warm at 1300°C for 30h , so that the chromium trioxide is reduced by carbon black, t...

Embodiment 3

[0045] 1. Purification treatment of chromium trioxide powder: chromium trioxide powder with a purity >99.0% and an average particle size of 200 mesh is soaked and cleaned with 5% hydrochloric acid solution at 60°C for 5 hours, and then washed with deionized water for 4 times. Dry at 150°C for 3 hours;

[0046] 2. Purification treatment of carbon black powder: put carbon black powder with sulfur content <0.05% and average particle size of 50μm into a vacuum furnace, raise the temperature to 1200°C, and then pass in hydrogen to control the vacuum degree at 40000Pa~50000Pa , keep warm for 2 hours, cool down and take out;

[0047] 3. Mix 100 kg of purified chromium trioxide powder and 25 kg of carbon black powder with a three-dimensional mixer for 2 hours to obtain a mixed powder; add the mixed powder to deionized water in batches, and each batch of mixed powder is 20 kg , mixed with 5kg of deionized water, and then stirred evenly to form a mixed wet material;

[0048] 4. Press ...

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PUM

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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...

Claims

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Application Information

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IPC IPC(8): C22B34/32C22B5/10
CPCY02P10/20
Inventor 林文汉林晨星张海涛任雷
Owner JINZHOU NEWROUTE HYPERPURE MATERIAL CO LTD
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