Method for preparing calcium carbonate and co-producing sulfate by utilizing industrial desulfurization gypsum

A desulfurization gypsum and sulfate technology, which is applied in the preparation of ammonium sulfate, calcium carbonate/strontium/barium, urea derivatives, etc., can solve problems such as undeveloped, and achieve the goal of avoiding carbon emissions, protecting the ecological environment, and reducing mining Effect

Pending Publication Date: 2021-07-23
湖南西林环保材料有限公司
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

At present, there is no substantive and operable method and process research in this field at home and abroad

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  • Method for preparing calcium carbonate and co-producing sulfate by utilizing industrial desulfurization gypsum

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Effect test

Embodiment 1

[0040] (1) Pretreat the zinc-containing heavy metal desulfurization gypsum to make a gypsum slurry with a mass concentration of 35%, wherein the zinc concentration is 10.7mg / L;

[0041] (2) The gypsum slurry is sent to the desulfurization gypsum reactor with a pump, and the concentration of 1.8 equivalents is sent into the desulfurization gypsum reactor by a pump with a concentration of 15%, so that the pH value of the slurry is controlled between 8 and 10, fully stirred, Feed sufficient carbon dioxide gas simultaneously, control reaction time 1.5 hours, obtain the mixed solution containing calcium carbonate solid precipitate and ammonium sulfate salt, total reaction formula is:

[0042] CaSO 4 2H 2 O+CO 2 +2NH 3 ·H 2 O=CaCO 3 ↓+(NH 4 ) 2 SO 4 +3H 2 o

[0043] (3) The mixed solution is washed by pressure filtration to obtain calcium carbonate slag and a mass concentration of about 7.4% ammonium sulfate aqueous solution, with a zinc concentration of 10.5 mg / L;

[004...

Embodiment 2

[0049] (1) Pretreat the zinc-containing heavy metal desulfurization gypsum to make a gypsum slurry with a mass concentration of 35%, wherein the zinc concentration is 10.7mg / L;

[0050] (2) Send the gypsum slurry to the desulfurization gypsum reactor with a pump, and send 1.8 equivalents of ammonia water with a concentration of 15% into the desulfurization gypsum reactor to control the pH value of the slurry between 8 and 10, and add 0.15 The triethanolamine of % gypsum slurry quality is as catalyzer, fully stirs, feeds sufficient carbon dioxide gas simultaneously, controls reaction time 0.7 hour, obtains the mixed solution containing calcium carbonate solid precipitate and ammonium sulfate salt, and total reaction formula is:

[0051] CaSO 4 2H 2 O+CO 2 +2NH 3 ·H 2 O=CaCO 3 ↓+(NH 4 ) 2 SO 4 +3H 2 o

[0052] (3) The mixed solution is washed by pressure filtration to obtain calcium carbonate slag and a mass concentration of about 7.8% ammonium sulfate aqueous solution...

Embodiment 3

[0058] (1) Pretreating fluorine-containing desulfurized gypsum to make gypsum slurry with a mass concentration of 15%;

[0059] (2) Send the gypsum slurry to the desulfurization gypsum reactor with a pump, and send 2 equivalents of 10% ammonia water into the desulfurization gypsum reactor with a pump to control the pH value of the slurry between 8 and 10, fully stir, and simultaneously Feed a sufficient amount of carbon dioxide gas, and the reaction time is 1.5 hours to obtain a mixed solution containing calcium carbonate solid precipitate and ammonium sulfate salt, and the total reaction formula is:

[0060] CaSO 4 2H 2 O+CO 2 +2NH 3 ·H 2 O=CaCO 3 ↓+(NH 4 ) 2 SO 4 +3H 2 o

[0061] (3) The mixed solution is filtered and washed to obtain calcium carbonate slag and a mass concentration of about 8.2% ammonium sulfate aqueous solution, and the fluorine concentration is 51 mg / L;

[0062] (4) After drying the calcium carbonate slag, collect and obtain a calcium carbonate ...

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Abstract

The invention discloses a method for preparing calcium carbonate and co-producing sulfate by utilizing industrial desulfurization gypsum, and the method comprises the following steps: carrying out size mixing treatment on the desulfurization gypsum to obtain gypsum slurry, adjusting the gypsum slurry to be alkaline by adopting an alkaline compound, introducing carbon dioxide gas for reaction, and after the reaction is finished, carrying out solid-liquid separation, and obtaining a calcium carbonate product and a sulfate solution; carrying out impurity removal treatment on the sulfate solution, and concentrating and crystallizing to obtain a sulfate product. According to the method, the maximum resource comprehensive utilization of the desulfurized gypsum can be realized, a high-purity calcium carbonate product can be obtained and can be returned to the flue gas desulfurization process of enterprises in the electric power industry, the fluorine chemical industry and the metal smelting industry, and byproducts such as sulfate (ammonium sulfate) can be obtained and can be used as fertilizers or industrial raw materials for agricultural production; virtuous cycle of the whole production and manufacturing process is realized, comprehensive utilization of sulfur and calcium resources and emission reduction of carbon are promoted, and large-scale popularization and application are facilitated.

Description

technical field [0001] The invention relates to a method for treating desulfurized gypsum, in particular to a method for preparing calcium carbonate and co-production of sulfate products from industrial desulfurized gypsum containing impurities, and belongs to the technical field of solid waste treatment. Background technique [0002] Desulfurization gypsum is a by-product formed by limestone-gypsum wet method or calcium hydroxide desulfurization of sulfur-containing flue gas and wastewater in coal-fired power, smelting, fluorine chemical industry, cement, aluminum electrolysis and other industries. The main raw material used is limestone mining and processing Affects the local ecological environment, and the by-product desulfurized gypsum is mainly used as a cement retarder or for making gypsum products, improving soil and roadbed backfill, etc. However, due to the serious oversupply of the desulfurized gypsum market, there is still a huge amount of desulfurized gypsum that ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01F11/18C01C1/24C07C273/02C07C275/02
CPCC01F11/18C01C1/24C07C273/02C01P2006/80C07C275/02
Inventor 王定华王俊陈志玮傅湘龙胡洋王平山
Owner 湖南西林环保材料有限公司
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