High-efficiency, energy-conservation and clean method for producing chromate

A manufacturing method and chromate technology, applied in the direction of chromate/dichromate, etc., can solve the problems of little commercial significance, failure to realize economic operation, complicated operation, etc. The effect of reaction efficiency

Active Publication Date: 2009-08-19
青海省博鸿化工科技股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The method for producing chromate with ferrochrome as raw material is seen in the reports of former Soviet Union patents 1142448, 1235823, 1527168, Japanese patent patent No. 83-1049 and U.S. Patent US3932598. The method is to add sodium carbonate and roast at high temperature in a rotary kiln. There are three-firing and two-firing processes. Although the process has been opened up in the former Soviet Union and an expanded production line has been established, the operation is complicated and economical operation has not been realized, and the commercial significance is not great.

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  • High-efficiency, energy-conservation and clean method for producing chromate

Examples

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Effect test

example 1

[0034] Adopt ferrochrome with 60.10% chromium content, 30.40% iron content, 7.10% carbon content and 2.50% silicon content as raw material to prepare the reaction initial solution. The formula is 100g ferrochrome, 80g caustic soda, and 1000mL water, which are placed in a 3000mL reaction kettle. The cold state is filled with oxygen into the kettle, and the oxygen pressure is 3.55MP. The heating voltage is 180v, the stirring speed is 350rpm, the heating reaction is carried out at 280°C for 30 minutes, the temperature is naturally cooled to room temperature and the material is discharged, and the solid-liquid separation is carried out. The filter cake is washed many times until there is no characteristic color of hexavalent chromium, and the chromium conversion is detected. The rate is 81.52%. Obtained 49.1 g of reddish-brown dry filter cake, containing 26.11% of chromium, 69.86% of iron and 4.02% of silicon as oxides.

example 2

[0036] Adopt ferrochrome with 60.10% chromium content, 30.40% iron content, 7.10% carbon content, and 2.50% silicon content as raw material to prepare the reaction initial solution. The formula is 200g ferrochrome, 200g caustic soda, and 1000mL water, which are placed in a 3000mL reaction kettle. The cold state is filled with oxygen into the kettle, and the oxygen pressure is 7.10MP. The heating voltage is 180v, the stirring speed is 350rpm, the heating reaction is carried out, and the temperature is kept at 280°C for 10 minutes, the temperature is naturally cooled to room temperature, and the solid-liquid separation is carried out. The rate is 85.94%. 148.4 g of reddish-brown dry filter cake was obtained, containing 21.19% of chromium, 74.52% of iron and 4.29% of silicon as oxides.

example 3

[0038]Adopt ferrochrome with 60.10% chromium content, 30.40% iron content, 7.10% carbon content and 2.50% silicon content as raw material to prepare the reaction initial liquid. The formula is 200g ferrochrome, 180g caustic soda, and 500mL water, which are placed in a 3000mL reaction kettle. The cold state is filled with oxygen into the kettle, and the oxygen pressure is 5.92MP. The heating voltage is 180v, the stirring speed is 350rpm, the heating reaction is carried out at 280°C for 20 minutes, the temperature is naturally cooled to room temperature and the material is discharged, and the solid-liquid separation is carried out. The filter cake is washed many times until there is no characteristic color of hexavalent chromium, and the chromium conversion is detected. The rate is 75.86%. 111.7 g of reddish-brown dry filter cake was obtained, containing 31.59% of chromium, 64.69% of iron and 3.72% of silicon as oxides.

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Abstract

The invention provides a method for producing chromate with high efficiency, energy conservation and cleanness. The method uses chromium iron as a raw material, and carries out oxidation dissolution in high-temperature high-pressure aqueous alkali to separate solid and liquid after temperature and pressure reduction so as to obtain a chromate solution, water and ferric oxide or mixture of the water, ferric oxide and chrome oxide. A high-temperature high-pressure reactor is used as the reactor of the method so as to greatly improve equipment efficiency and production efficiency. The method realizes autothermal reaction by system reaction heat to achieve the aim of energy conservation, and is an energy-saving process of chromate production. The method does not need external fuel to supply heating and does not generate waste gas, and the reaction precipitate is the water and the ferric oxide or the mixture of the water, the ferric oxide and the chrome oxide, wherein the water and the ferric oxide or the mixture of the water, the ferric oxide and the chrome oxide can be used for preparing chromium iron paint without generating waste residue; and washing of the precipitate adopts countercurrent washing, and washing water is used for preparing a reaction initial solution without generating waste water. The method does not generate the three wastes, and is a clean process for producing the chromate.

Description

Technical field: [0001] The invention belongs to a method for producing chromium chemical industry and chromium salt, in particular to a method for producing chromate, which can be used to produce sodium chromate, potassium chromate, lithium chromate and other products. Background technique: [0002] Chromate is an important inorganic chemical basic raw material, used in the production of sodium dichromate (potassium, lithium), chromic anhydride, chromium oxide, metal chromium and other products. Chromium compounds are widely used in chemical industry, metallurgy, pigment, leather tanning, printing and dyeing, electroplating, medicine and other industries. The existing industrialized production technology at home and abroad is to use sodium carbonate high-temperature oxidation roasting to decompose chromite process. This process is to use chromite as raw material, and add 80% to 120% of the theoretical amount of sodium carbonate and chromite. 6 times the filler is roasted i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G37/14
Inventor 梅海军王劲松宋卫国尹新建杨永飚王爱山张忠
Owner 青海省博鸿化工科技股份有限公司
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