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Method for clean production of chromium sesquioxide by using chromite as raw material

A technology of chromium trioxide and clean production, applied in the direction of chromium trioxide, chromium oxide/hydrate, etc., which can solve the problems of high energy consumption and high preparation cost

Active Publication Date: 2016-12-07
于佳湲 +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Most of the above-mentioned routes are obtained from chromite ore by alkali method to obtain hexavalent chromium salt, and then from hexavalent chromium salt to obtain dichromium trioxide. The pollution problem of hexavalent chromium cannot be avoided in the production process, and the raw materials used in the production process are all Sodium chromate deep-processed products also have problems such as high preparation cost and high energy consumption

Method used

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  • Method for clean production of chromium sesquioxide by using chromite as raw material
  • Method for clean production of chromium sesquioxide by using chromite as raw material
  • Method for clean production of chromium sesquioxide by using chromite as raw material

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Embodiment 1

[0027] The production method of present embodiment chromium trioxide is as figure 1 Shown, it is prepared according to the following steps:

[0028] One, take by weighing 200g chromite ore, calculate the amount 380g of the vitriol oil required for reaction according to the content of metal element chromium in the chromite ore, and dilute the vitriol oil required to concentration to be 58%;

[0029] 2. Add the dilute sulfuric acid, chromite and 20g of chromic anhydride prepared in step 1 into the autoclave in turn, react at 125°C for 1 hour, and separate the solid and liquid. The obtained liquid phase is a mixture of chromium sulfate, iron sulfate, magnesium sulfate and aluminum sulfate solution;

[0030] 3. Dilute the Fe in the mixed solution with air and hydrogen peroxide that do not introduce other impurities 2+ All oxidized to Fe 3+ , adjusting the pH value of the mixed solution to 2.7 with ammonia water containing ammonium ions;

[0031] 4. Add the mixed solution treat...

Embodiment 2

[0036] Chromium trioxide of the present embodiment is prepared according to the following steps:

[0037] One, take by weighing 200g chromite ore, calculate the amount 380g of the concentrated sulfuric acid needed for reaction according to the content of metal element chromium in the chromite ore, and dilute the required concentrated sulfuric acid to concentration and be 80%;

[0038] 2. Add the dilute sulfuric acid, chromite and 20g of chromic anhydride prepared in step 1 into the autoclave successively, react at 120°C for 1.2h, and separate the solid and liquid. The obtained liquid phase is a mixture of chromium sulfate, iron sulfate, magnesium sulfate and aluminum sulfate. mixture;

[0039] 3. Dilute the Fe in the mixed solution with oxygen that does not introduce other impurities 2+ All oxidized to Fe 3+ , adjusting the pH value of the mixed solution to 2.8 with ammonium bicarbonate containing ammonium ions;

[0040] 4. Add the mixed solution treated in step 3 into an a...

Embodiment 3

[0045] Chromium trioxide of the present embodiment is prepared according to the following steps:

[0046] One, take by weighing 200g chromite ore, calculate the amount 380g of the vitriol oil needed for reaction according to the content of metal element chromium in the chromite ore, and dilute the vitriol oil required to concentration to be 70%;

[0047] 2. Add the dilute sulfuric acid, chromite and 20g of chromic anhydride prepared in step 1 into the autoclave in turn, react at 130°C for 3 hours, and separate the solid and liquid. The obtained liquid phase is a mixture of chromium sulfate, iron sulfate, magnesium sulfate and aluminum sulfate solution;

[0048] 3. Dilute Fe in the mixed solution with oxygen, air and hydrogen peroxide that do not introduce other impurities 2+ All oxidized to Fe 3 + , adjusting the pH value of the mixed solution to 3 with ammonia water or ammonium bicarbonate containing ammonium ions;

[0049]4. Add the mixed solution treated in step 3 into ...

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Abstract

The invention discloses a method for clean production of chromium sesquioxide by using chromite as a raw material. The method comprises the following steps of by using the chromite as the raw material and chromic anhydride as an oxidizer, enabling the chromite and the chromic anhydride to be dissolved in sulphuric acid so as to obtain a mixed solution of elements of chromium sulfate, ferric sulfate and the like; by using an ammonium salt deferrization technique, realizing chromium-iron separation in the solution; adjusting the acidity of the mixed solution after separation so as to obtain precipitation of chromium hydroxide and aluminum hydroxide; performing evaporative crystallization on a mixed solution of ammonium sulphate and magnesium sulphate after chromium and aluminum are precipitated so that a nitrogen and magnesium fertilizer is prepared; performing liquid-solid separation on obtained liquid of chromium hydroxide and aluminum hydroxide after alkali dissolution so as to obtain and chromium hydroxide solids; performing washing and calcining on the chromium hydroxide solids so as to obtain chromium oxide products; and preparing aluminum hydroxide products by a Bayer method from a solution obtained through separation. The method disclosed by the invention is simple in preparation technology, by-products are mixtures of the aluminum hydroxide, the ammonium sulphate and the magnesium sulphate, waste and pollution are not generated, the synthesizing cost is low, and the energy consumption is low. The method has great popularization and application potentials in the field of green production of the chromium sesquioxide.

Description

technical field [0001] The invention relates to the field of preparation of metallic chromium and chromium salts thereof, in particular to a method for cleanly producing chromium trioxide by using chromite as raw material. Background technique [0002] Chromium trioxide (also known as chromium oxide green Cr 2 o 3 ) are widely used in metallurgical and chemical industries. Because of its good stability, it can also be used in paint, glass, enamel, cement colorants, and can also be used in organic catalysts. [0003] Chromium trioxide preparation methods include: reduction method (reduction firing by mixing sodium dichromate or potassium dichromate with ammonium sulfate or ammonium chloride, sulfur, etc.), thermal decomposition method (using chromic anhydride or ammonium dichromate , thermal decomposition of chromium hydroxide) and other methods. The preparation of chromium trioxide in foreign countries mainly adopts the thermal reduction method of sodium dichromate. Sodi...

Claims

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Application Information

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IPC IPC(8): C01G37/033
CPCC01G37/033C01P2006/80
Inventor 于佳湲于广新徐宏军冯强
Owner 于佳湲
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