Method for preparing granular ammonium sulfate and calcium carbonate by chemical gypsums via low-temperature transformation

A chemical gypsum and low-temperature conversion technology, applied in the field of phosphorus chemical industry, can solve the problems of chemical gypsum environmental pollution ammonium sulfate production costs, etc., to achieve the effect of avoiding secondary pollution, reducing investment costs and operating costs, and reducing procedures

Active Publication Date: 2012-10-03
SINOFERT HOLDINGS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above technical problems, the object of the present invention is to provide a kind of technology that takes chemical gypsum as raw material to manufacture granular ammonium sulfate and calcium carbonate simultaneously, solves the environmental pollution of chemical gypsum and the production cost problem of ammonium sulfate

Method used

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  • Method for preparing granular ammonium sulfate and calcium carbonate by chemical gypsums via low-temperature transformation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Such as figure 1 As shown, (1) first pretreat seven kinds of chemical gypsum including phosphogypsum, flue gas desulfurization FGD gypsum, fluorine gypsum, citrate gypsum, boron gypsum, titanium gypsum and Glauber’s salt gypsum, and wash them with hot water at 70°C to remove the water-soluble phosphorus , sulfur trioxide, and soluble salts of potassium, sodium, magnesium, and aluminum; returned to the phosphoric acid, ammonium phosphate production system, used as process water for recycling, or sent to the sewage treatment plant for discharge after reaching the standard.

[0029] (2) Use the pretreated chemical gypsum to prepare ammonium sulfate solution to produce calcium carbonate raw materials that meet the requirements of Portland cement production;

[0030] (2.1) Add water to the chemical gypsum from (1) to re-slurry, adjust the pH value of the solution to about 8 with ammonia gas, keep it at a temperature of 45°C, and carry out metathesis reaction by passing carbo...

Embodiment 2

[0038] Such as figure 1 As shown, (1) first pretreat seven kinds of chemical gypsum including phosphogypsum, flue gas desulfurization FGD gypsum, fluorine gypsum, citrate gypsum, borogypsum, titanium gypsum and Glauber’s salt gypsum. Wash with water to remove water-soluble phosphorus, sulfur trioxide, and soluble salts of potassium, sodium, magnesium, and aluminum; return to the phosphoric acid and ammonium phosphate production system, and reuse it as process water, or send it to the sewage treatment plant for treatment and discharge after reaching the standard.

[0039] (2) Use the pretreated chemical gypsum to prepare ammonium sulfate solution to produce calcium carbonate raw materials that meet the requirements of Portland cement production;

[0040] (2.1) Add water to the chemical gypsum from (1) for reslurry, and adjust the pH value of the solution to about 10 with ammonia gas, keep it at a temperature of 50°C, and carry out metathesis reaction by passing carbon dioxide g...

Embodiment 3

[0048] Such as figure 1 As shown, (1) first pretreat seven kinds of chemical gypsum including phosphogypsum, flue gas desulfurization FGD gypsum, fluorine gypsum, citrate gypsum, borogypsum, titanium gypsum and Glauber’s salt gypsum. Wash with water to remove water-soluble phosphorus, sulfur trioxide, and soluble salts of potassium, sodium, magnesium, and aluminum; return to the phosphoric acid and ammonium phosphate production system, and reuse it as process water, or send it to the sewage treatment plant for treatment and discharge after reaching the standard.

[0049] (2) Use the pretreated chemical gypsum to prepare ammonium sulfate solution to produce calcium carbonate raw materials that meet the requirements of Portland cement production;

[0050] (2.1) Add water to the chemical gypsum from (1) for reslurry, and adjust the pH value of the solution to about 8 with ammonia gas, and keep it at a temperature of 45°C. Introduce carbon dioxide gas to make it undergo double de...

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Abstract

The invention discloses a process for preparing granular ammonium sulfate and calcium carbonate by chemical gypsum via low-temperature transformation, and relates to the field of resource utilization of industrial byproduct gypsums and environmental protection and control. The process is characterized by taking chemical gypsums (such as phosphogypsum, flue gas desulfurization (FGD) gypsum, fluorgypsum, citric gypsum, boron gypsum, titanium gypsum, and mirabilite gypsum) as raw materials and comprising the steps of pretreatment of raw materials, low-temperature transformation of the chemical gypsums, solid-liquid separation and washing, concentration of ammonium sulfate and granulation of ammonium sulfate. The process has the advantages of being wide in raw material sources, solving the land occupation and environment pollution problems of waste residues of the chemical gypsums, and realizing the cyclic utilization of sulfur resources; and according to the process, the large-scale production is easy to realize, the technique is advanced, the energy consumption is low, the benefit is high and no waste residue is discharged.

Description

technical field [0001] The invention belongs to the field of phosphorus chemical industry, and in particular relates to a preparation method of large-grain ammonium sulfate. Background technique [0002] Chemical gypsum mainly includes phosphogypsum, flue gas desulfurization FGD gypsum, fluorine gypsum, citrate gypsum, boron gypsum, titanium gypsum and mirabilite gypsum, etc. [0003] Phosphogypsum is a by-product of sulfuric acid decomposition of phosphate rock to extract wet-process phosphoric acid. 2 o 5 It will produce 4.5-5.5 tons of phosphogypsum, the color is gray or slightly yellow, the pH value is between 2-4, and the main chemical composition is calcium sulfate dihydrate (CaSO 4 .2H 2 O), containing a small amount of fluorine compounds, acid insolubles, phosphoric acid residue, etc.; at present, the annual discharge of phosphogypsum in the world is more than 150 million tons; the domestic annual discharge of phosphogypsum is close to 50 million tons, which is co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F11/18C01C1/24
Inventor 盛勇周佩梅胜明蹇民谭伟胡满川陈明凤郑开元江涛陈鹏
Owner SINOFERT HOLDINGS
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