Process for preparing magnesium hydroxide whiskers and calcium sulfate from phosphorus tailings

A technology of magnesium hydroxide and phosphorus tailings, which is applied in the field of waste resource utilization and functional nanomaterials, can solve the problems of phosphorus tailings accumulation and environmental pollution, and achieve the effect of high utilization rate and low production cost

Inactive Publication Date: 2018-11-06
WUHAN INSTITUTE OF TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to provide a process for producing magnesium hydroxide whiskers and calcium sulfate using phosphorus tailings as raw materials, effectively solving the comprehensive problems of phosphorus tailings accumulation and environmental pollution, and improving the comprehensive utilization rate of magnesium resources associated with phosphate rocks; The by-product calcium sulfate can be used for plaster bandages, making plaster models, chalk, handicrafts, etc. At the same time, the solid waste filtered out during the acid hydrolysis process can be used for building materials

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] Put 60 kg of phosphorus tailings obtained from flotation into the acid hydrolysis reactor, add 4.415 liters of water, and after reaching the preset temperature of 70°C, slowly add 114.087 liters of 38% hydrochloric acid under stirring conditions, react for 3.5 hours, filter and wash Carry out solid-liquid separation; add 0.323 liters of 30% hydrogen peroxide to the filtrate obtained in the previous step, add ammonia water dropwise under stirring conditions, control the pH value of the filtrate to 6.7, react for 1 hour, filter, and obtain a mixed solution containing magnesium chloride and calcium chloride, labeled It is solution A; put 66.228 kilograms of phosphorus tailings obtained by flotation into another acid hydrolysis reactor, add 247.623 liters of water, after reaching the preset temperature of 50 ° C, slowly add 38.814 liters of 98wt% sulfuric acid under stirring conditions, and react 2 After one hour, filter and wash for solid-liquid separation; add 0.356 liters...

Embodiment 2

[0048] Put 60 kg of phosphorus tailings obtained by flotation into the acidolysis reactor, add 4.415 liters of water, and after reaching the preset temperature of 50°C, slowly add 114.087 liters of 38wt% hydrochloric acid under stirring conditions for reaction, and react for 3.5 hours, filter, Wash for solid-liquid separation; add 0.323 liters of 30wt% hydrogen peroxide to the filtrate obtained in the previous step, and add ammonia water dropwise under stirring conditions, control the pH value of the filtrate to 6.7, react for 1 hour, and filter to obtain a mixture containing magnesium chloride and calcium chloride. Solution, marked as solution A; put 66.228 kilograms of phosphorus tailings obtained by flotation into another acid hydrolysis reactor, add 247.623 liters of water, after reaching the preset temperature of 50 ° C, slowly add 38.814 liters of 98wt% sulfuric acid under stirring conditions, After reacting for 2 hours, filter and wash to carry out solid-liquid separatio...

Embodiment 3

[0051] Put 65.5 kg of phosphorus tailings obtained from flotation into the acid hydrolysis reactor, add 4.820 liters of water, and after reaching the preset temperature of 30°C, slowly add 124.545 liters of 38wt% hydrochloric acid under stirring conditions, react for 3.5 hours, filter and wash Carry out solid-liquid separation; add 0.353 liters of 30wt% hydrogen peroxide to the filtrate obtained in the previous step, add ammonia water dropwise to control the pH value of the filtrate to 6.7, react for 1 hour, and filter to obtain a mixed solution containing magnesium chloride and calcium chloride, which is marked as solution A; Put 72.300 kg of phosphorus tailings obtained from flotation into another acid hydrolysis reactor, add 270.322 liters of water, and after reaching the preset temperature of 50°C, slowly add 42.372 liters of 50wt% sulfuric acid under stirring conditions, react for 2 hours, filter, Wash for solid-liquid separation; add 0.389 liters of 30wt% hydrogen peroxid...

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Abstract

The invention discloses a process for preparing a magnesium hydroxide whisker and calcium sulfate by using phosphate tailings as raw materials. The process comprises the following steps: mixing phosphate tailings obtained through flotation with hydrochloric acid to react and obtaining a mixed solution containing magnesium chloride and calcium chloride after impurity removal and filtration; mixing the phosphate tailings with sulfuric acid to react and obtaining a magnesium sulfate solution after impurity removal and filtration; mixing the two solutions and obtaining a calcium sulfate precipitate and magnesium chloride filtrate after reaction and filtration; adding alkali liquor to the magnesium chloride filtrate and obtaining a liquid-solid mixture containing a basic magnesium chloride whisker after reaction and aging; adding an alkaline solution later and obtaining the magnesium hydroxide whisker after reaction and aging; returning ammonia gas recovered through gas stripping of the filtrate to the section for producing the magnesium hydroxide whisker and returning the liquid phase after gas stripping to the acidolysis section after the liquid phase is crystallized to remove ammonium chloride. The process has the beneficial effects that the phosphate tailings are used as the raw materials to produce the magnesium hydroxide whisker and the byproduct calcium sulfate, and meanwhile, higher value application of the phosphate chemical solid wastes and cleaner production are achieved by recycling surplus ammonia gas.

Description

technical field [0001] The invention belongs to the field of waste resource utilization and functional nanometer materials, and in particular relates to a process for producing magnesium hydroxide whiskers and calcium sulfate by using phosphorus tailings as raw materials. Background technique [0002] Phosphate rock is the main fertilizer needed for global agricultural production—the raw material of phosphate fertilizer, an important guarantee for global food production; it is also a raw material for the production of fine chemical products. More than 90% of the phosphate rock grade in my country is lower than 26%, with an average grade of about 17%. With the continuous mining and utilization of phosphate rock resources, the development and utilization of low-grade and refractory phosphate rock resources have attracted the attention of many researchers. The content of magnesium, iron and aluminum oxides in most low-grade ores in my country is high, and it needs to go throug...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C30B29/62C30B29/10C30B7/14C01F11/46
CPCC01F11/46C30B7/14C30B29/10C30B29/62
Inventor 刘生鹏丁一刚吴梦许莉莉龙秉文邓伏礼
Owner WUHAN INSTITUTE OF TECHNOLOGY
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