Method for improving color of chromium oxide green

A technology of chromium oxide green and chromium oxide, applied in the direction of chromium trioxide, chromium oxide/hydrate, etc., can solve the problem of chromium oxide green dimming, etc., and achieve the effect of good tinting strength and bright color

Active Publication Date: 2012-07-11
GANSU JINSHI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for improving the green luster of chromium oxide to solve the shortcoming of darkening the green color of chromium oxide prepared by thermal decomposition of traditional chromic anhydride

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Mix chromic anhydride and ammonium chloride at a mass ratio of 100:2. When the high temperature zone temperature of the rotary kiln reaches 1050℃, start feeding, roasting in the rotary kiln for 4 hours, and the obtained chromium oxide green is crushed to 600 mesh. After more than 90%, the color difference analysis is performed, and the results are as follows:

[0018] projecta*b*L* DE* Sample-12.4712.5334.84 No additives-11.6411.4633.252.07 Add ammonium chloride-12.4912.9434.810.41

[0019] The a*, b*, L*, DE* in the project are the national 1976 CIE unified color space.

[0020] After analysis, the content of chromium anhydride chromium green obtained by adding ammonium chloride and roasting is 99.58%, the coloring power is 100.39%, the color is bright, the brightness is better, and it is relatively saturated, which meets the requirements of pigment-grade chromium oxide green.

Embodiment 2

[0022] Mix chromic anhydride and potassium fluoride at a mass ratio of 100:3.5. When the temperature of the rotary kiln reaches 1075℃, start feeding. The material is roasted in the rotary kiln for 3.5h. The obtained chromium oxide green is crushed to 600 meshes. The pass rate is greater than After 90%, the color difference analysis is performed, and the results are as follows:

[0023] projecta*b*L* DE* Sample-12.4712.5334.84 No additives-13.5713.6035.811.82 Added potassium fluoride-12.6112.5634.560.31

[0024] After analysis, the content of chromium anhydride chrome green obtained by adding potassium fluoride and roasting is 99.65%, the tinting strength is 101.52%, the color is bright, the brightness is better, and it is relatively saturated, which meets the requirements of pigment-grade chrome oxide green.

Embodiment 3

[0026] Mix chromic anhydride and sodium fluoride in a mass ratio of 100:5. When the temperature of the rotary kiln reaches 1100℃, start feeding. The materials are roasted in the rotary kiln for 3 hours. The obtained chromium oxide green is crushed to 600 meshes, and the pass rate is greater than 90 The color difference analysis is performed after %, and the results are as follows:

[0027] projecta*b*L* DE* Sample-12.4712.5334.84 No additives-13.5713.6035.811.82 Add sodium fluoride -12.6512.5534.810.18

[0028] After analysis, the content of chromium anhydride chromium green obtained by adding sodium fluoride and roasting is 99.58%, the tinting strength is 100.82%, the color is bright, the brightness is better, and it is relatively saturated, which meets the requirements of pigment-grade chromium oxide green.

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PUM

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Abstract

The invention discloses a method for improving the color of chromium oxide green, and aims to solve the problem that the tone of the traditional chromium oxide green prepared by thermally decomposing chromic anhydride is dark. The method comprises the following steps of: A, adding an additive in an amount which is 2 to 5 percent of the mass of the chromic anhydride, uniformly mixing the additive and the chromic anhydride, putting into a rotary kiln, and performing thermal decomposition reaction, wherein the additive is one of ammonium chloride, potassium fluoride and sodium fluoride; B, controlling the temperature of a high-temperature zone of the rotary kiln to 1,050-1,100 DEG C, feeding into the rotary kiln, and roasting for 3 to 4 hours; and C, grinding the chromium oxide green obtained by roasting into 600-mesh powder with the passing rate of over 90 percent, packaging and delivering after the product is qualified through detection. In order to improve the color brightness and coloring power of the chromic anhydride chromium green, the additive is added in the process of preparing the chromium oxide green by thermally decomposing the chromic anhydride to promote pigment synthesis reaction, and reducing atmosphere when the chromic anhydride is subjected to thermal decomposition is enhanced, so the chromium oxide green obtained by thermal decomposition has bright color, and the brightness and coloring power of the chromium oxide green are increased.

Description

technical field [0001] The invention belongs to the field of chromium salt production and relates to a method for improving the green luster of chromium oxide. Background technique [0002] Chromium oxide green is the base of green pigments, which is olive green, and its trivalent chromium element is a color-forming element; it has excellent heat resistance and weather resistance, and also has excellent acid and alkali resistance and is non-toxic, so it has become Traditional green colorant. [0003] However, the chromium oxide green produced by the traditional thermal decomposition of chromic anhydride has the disadvantages of dark tone and not bright enough, and affects its decorative properties, and its application is also limited. Contents of the invention [0004] The purpose of the present invention is to provide a method for improving the green luster of chromium oxide, so as to solve the disadvantages of darkening the green color of chromium oxide prepared by ther...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G37/033
Inventor 张忠元张宏军杨岗谢希智张大波牛永阳杨亮亮
Owner GANSU JINSHI CHEM
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