Process for preparing iron oxide red by using sulfuric acid crystal seed mixed acid method and products thereby

A technology of iron oxide red and sulfuric acid method, which is applied in the direction of chemical instruments and methods, inorganic pigment treatment, fibrous fillers, etc., can solve the problems of atmospheric environmental pollution, large amount of emission, and increased production costs, so as to solve air pollution and improve work Effects of environment and cost reduction of seed crystal raw materials

Inactive Publication Date: 2005-11-23
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the actual production process, the nitric acid method still consumes a large amount of nitric acid during the production process, which increases the production cost, and will release a large amount of harmful gas nitrogen oxides, causing serious air pollution.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] In a 1.0 cubic meter seed crystal cylinder (container configured with iron oxide red seed crystals), the preparation concentration is 0.50 cubic meters of ferrous sulfate heptahydrate of 35g / L, slowly adding sodium hydroxide under stirring to a pH value of 10.2, the reaction temperature At 25°C, react for 1.0h to obtain iron oxide red seeds. Then mix the obtained red iron oxide seed crystals with water at a ratio of 1:1, add 0.5mg / L polyacrylamide ammonium, stir rapidly, and when the seed crystals settle down to 1 / 4 of the original total volume, extract the sulfuric acid from the upper part. Add clear water after the salt liquid layer, and then stir and settle. After repeatedly extracting the sulfate-containing liquid layer, adding clear water, and then stirring and settling for 3 times, the iron oxide red seeds after washing were obtained. Then pump the red iron oxide seeds after washing into the two-step oxidation cylinder filled with fluffy iron sheets, stir with ai...

Embodiment 2

[0025] Prepare 0.50 cubic meters of ferrous sulfate heptahydrate with a concentration of 35g / L in a 1.0 cubic meter seed crystal tank, slowly add sodium hydroxide to a pH value of 9.7 under stirring conditions, and react at a temperature of 20°C for 1.3 hours to prepare Obtain iron oxide red crystal seeds. Then mix the obtained red iron oxide seed crystals with water at a ratio of 1:1, add 1.0mg / L polyacrylamide ammonium, and stir rapidly. Add clear water after the salt liquid layer, and then stir and settle. After repeatedly extracting the sulfate-containing liquid layer, add water, and then stir the sedimentation process 5 times. Then pump the water-washed seed crystals into a two-step oxidation cylinder filled with fluffy iron sheets, stir with air for 25 minutes, add 98% sulfuric acid to pH 4.5 when the temperature is raised to 72°C with steam, and add ferrous sulfate heptahydrate solution to ferrous The concentration is 8.93g / L, and the reaction temperature is maintaine...

Embodiment 3

[0028] Prepare 0.50 cubic meters of ferrous sulfate heptahydrate with a concentration of 40 g / L in a 1.0 cubic meter seed crystal tank, slowly add sodium hydroxide under stirring conditions to a pH value of 9.1, and the reaction temperature is 30 ° C. React for 1.2 hours to prepare Obtain iron oxide red crystal seeds. Then mix the obtained red iron oxide seed crystals with water at a ratio of 1:2, add 1.5mg / L polyacrylamide ammonium, and stir rapidly, and when the seed crystals settle down to 1 / 3 of the original total volume, extract the sulfuric acid from the upper part. Add clear water after the salt liquid layer, and then stir and settle. After repeatedly extracting the sulfate-containing liquid layer, add water, and then stir the sedimentation process 4 times. Then pump the water-washed seed crystals into a two-step oxidation cylinder filled with fluffy iron sheets, stir with air for 10 minutes, add 98% sulfuric acid to pH 5.0 when the temperature is raised to 73°C with s...

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Abstract

The invention relates to a process for preparing iron oxide red by using sulfuric acid crystal seed mixed acid method, which comprises preparing iron oxide red seed crystal with sulfuric acid process, then washing the iron oxide red seed crystal, lowering the content of sulphate and other impurities in the sulfuric acid process iron oxide red seed crystal, preparing iron oxide red slurry through two-step oxidization, finally dewatering, water scrubbing and drying to obtain the end product.

Description

technical field [0001] The invention relates to the field of preparation of inorganic chemical pigments, in particular to a method for preparing iron oxide red by a sulfuric acid seed mixed acid method and a product thereof. Background technique [0002] Iron oxide red is an ancient pigment. Humans began to use iron-based pigments in paintings about 20,000 years ago. Humans began to use natural iron oxide minerals, which were crushed and used as pigments. Later, due to the needs of industrial development, in order to prepare products with more purity and superior performance, artificially synthesized iron oxide pigments began to be developed around the 1950s, and now they have gradually replaced natural products. In recent years, synthetic products have accounted for more than 80% of the total output of pigments. [0003] The production process of iron oxide red pigment can generally be divided into two major processes: dry process and wet proces...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09C1/24
Inventor 汪晓军肖丁许国雄
Owner SOUTH CHINA UNIV OF TECH
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