Method for preparing chromium oxide green pigment through hydrated chromium oxide

A technology of hydrated chromium oxide and chromium oxide green, which is applied in the direction of chromium trioxide, chromium oxide/hydrate, etc., can solve the problems of single color grade and unstable color performance, and achieve the effect of simple method and low cost

Inactive Publication Date: 2013-12-18
INST OF PROCESS ENG CHINESE ACAD OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to research and develop a control preparation method of a series of grade pigment-grade chromium oxide g

Method used

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  • Method for preparing chromium oxide green pigment through hydrated chromium oxide
  • Method for preparing chromium oxide green pigment through hydrated chromium oxide
  • Method for preparing chromium oxide green pigment through hydrated chromium oxide

Examples

Experimental program
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Effect test

Embodiment 1

[0036] Weigh 60g of potassium chromate into a material boat, put it into a tube furnace, raise the temperature to 600°C, and pass in hydrogen for reduction for 1.5 hours. During the reduction process, the hydrogen flow rate is 0.8L / min. After the reduced product was cooled in a reducing atmosphere, it was placed in 800 ml of water at 80°C, slurry-washed for 0.5 h, and washed 10 times. After washing, the material is separated by gravity sedimentation, filtered and dried to obtain hydrated chromium oxide of weak crystal and trigonal phase respectively. After the temperature of the muffle furnace was raised to 1050°C, the weakly crystalline hydrated chromium oxide was put into the furnace for calcination for 1.5 hours. After the calcined material is cooled with the furnace, after washing, filtering and drying, a dark green pigment-grade chromium oxide green product is obtained. The main performance indicators are shown in Table 1.

Embodiment 2

[0038] After heating 200ml of deionized water to boiling, add 81g / L of Na at the same time 2 S solution and 150g / L Na 2 Cr 2 o 7 Solution, control the pH to 11. The resulting solution was placed in a hydrothermal kettle and reacted at 250°C for 2h. After cooling, wash and filter, and disperse the resulting precipitate in 1500ml of H 3 PO 4 In a solution of 6.6g / L, heat to a slight boil, wash with pulp for 0.5h, filter, wash with water, and dry to obtain hydrated chromium oxide. Hydrated chromium oxide was placed in a tube furnace, and was calcined for 0.5h after heating up to 1300°C with the furnace in a nitrogen atmosphere. After calcination, the material was cooled with the furnace, washed, filtered, and dried to obtain a blue-green pigment-grade chromium oxide green product. The main performance indicators are shown in Table 1.

Embodiment 3

[0040]Weigh 60g of potassium chromate in a material boat, put it into a tube furnace, raise the temperature to 450°C, and pass in nitrogen-hydrogen mixed gas for reduction for 2 hours. During the reduction process, the flow rate of nitrogen gas is 0.2L / min, and the flow rate of hydrogen gas is 0.7L / min. . After the reduced product was cooled in a reducing atmosphere, it was placed in 1000ml of water at 60°C, slurried and washed for 0.5h, and washed 3 times. After washing, the material is filtered and dried to obtain hydrated chromium oxide. After the temperature of the muffle furnace was raised to 1000°C, the hydrated chromium oxide was put into the furnace for calcination for 2 hours, and then the calcined material was taken out immediately. After the calcined material is cooled, washed, filtered, and dried, a light green pigment-grade chromium oxide green product is obtained. The main performance indicators are shown in Table 1.

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Abstract

The invention discloses a method for preparing chromium oxide green pigment through hydrated chromium oxide. The method comprises the following steps of: calcining hydrated chromium oxide used as an active ingredient at 700-1,500 DEG C for more than 0.3 hour to obtain pigment-level chromium oxide green. The hydrated chromium oxide can be prepared by adopting a solid phase method (such as a method of reducing chromium salt gas), or a liquid phase method (such as precipitation, hydrothermal and the like). The content of chromium oxide in the obtained product is greater than 99%, and different trademarks of pigment-level chromium oxide green can be prepared simply by regulating the preparation technique and calcining conditions (temperature, time, atmosphere and feeding modes) of the hydrated chromium oxide. Compared with the prior art, the method for preparing the chromium oxide green pigment through hydrated chromium oxide has the advantage that additives are not needed for activating and sintering, the regulation and preparation of different trademarks of pigment-level chromium oxide green can be realized simply by regulating the preparation technique and calcining conditions of the hydrated chromium oxide.

Description

technical field [0001] The invention relates to a method for preparing an inorganic metal oxide pigment, more specifically, a method for preparing chromium oxide green pigment from hydrated chromium oxide. Background technique [0002] Chromium oxide green pigment has good stability, acid and alkali resistance, high temperature resistance, light and weather resistance. Mixture, electrostatic copying and so on. The unique color of chromium oxide green, which is similar to plant chlorophyll, can be used to prepare camouflage materials similar to green leaf clusters. Chromium oxide green pigments were used as camouflage coatings on weapons during World War II. As a pigment, chromium oxide green products have high quality requirements and must have good color performance, including chroma, tinting strength, hiding power, etc. [0003] The production of chromium oxide green pigment mainly adopts thermal decomposition of ammonium sulfate-sodium red alum (US4,040,860) and therma...

Claims

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Application Information

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IPC IPC(8): C01G37/033
Inventor 张红玲梁书婷李平徐红彬张懿徐诚王世君李邦东
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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