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Method for preparing calcium sulfide by reducing and decomposting gypsum through sulfur

A technology of calcium sulfide and gypsum, applied in chemical instruments and methods, sulfur compounds, magnesium/calcium/strontium/barium sulfide/polysulfide, etc., can solve the problems of high production cost, complicated operation, high energy consumption, etc., and achieve Reduced energy consumption, short production cycle and simple operation

Inactive Publication Date: 2011-05-11
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this scheme, although the conversion rate of calcium sulfate of phosphogypsum reduced to calcium sulfide is greatly improved, which can reach more than 95%, it is based on increasing the reaction temperature and passing complex technological processes such as pretreatment of raw materials, batching, and ball making. Therefore, it not only has high energy consumption, but also has a long process flow, complicated operation and high production cost.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Raw material 1: Phosphogypsum powder. The composition of phosphogypsum powder is shown in the table below, and the collection point is the phosphogypsum slag yard of Sichuan Gaoyu Group.

[0018] components

[0019] Raw material 2: sulfur (99.50% content).

[0020] Put 2000g of phosphogypsum powder into a quartz tubular reactor, preheat it for 30 minutes with nitrogen gas and raise the temperature to 800°C, and then bring the sulfur gasified in the gasifier into the nitrogen gas to make the sulfur gas occupy the reaction system. The mole fraction of the mixed atmosphere in the medium is 30%, and the gaseous sulfur and phosphogypsum are fully contacted and reacted for 1 hour under the condition that the quartz tube reactor is continuously rotated. After the reaction, the obtained block is the calcium sulfide product. Exhaust SO 2 For the production of sulfuric acid.

[0021] Calcium sulfide product composition analysis is as follows:

[0022] compo...

Embodiment 2

[0025] Raw material 1: Phosphogypsum powder. The composition of phosphogypsum powder is the same as in Example 1.

[0026] Raw material 2: sulfur (99.50% content).

[0027] First put 1000g of phosphogypsum powder into a quartz tube reactor, preheat it for 30 minutes by feeding carbon dioxide and raising the temperature to 600°C, and then bring the sulfur gasified in the gasifier into the sulfur gas by carbon dioxide, so that sulfur gas occupies the reaction system The mole fraction of the mixed atmosphere in the medium is 40%, and the gaseous sulfur and phosphogypsum are fully contacted and reacted for 2 hours under the condition that the quartz tube reactor is continuously rotated. After the reaction, the obtained block is the calcium sulfide product. Exhaust SO 2 For the production of sulfuric acid.

[0028] Calcium sulfide product composition analysis is as follows:

[0029] components

[0030] CaSO in phosphogypsum powder 4 The conversion rate to CaS was 95....

Embodiment 3

[0032] Raw material 1: Phosphogypsum powder. The composition of phosphogypsum powder is the same as in Example 1.

[0033] Raw material 2: sulfur (99.50% content).

[0034] First put 5000g of phosphogypsum powder into a quartz tube reactor, preheat it for 10 minutes by feeding nitrogen and sulfur dioxide and raising the temperature to 900°C, and then bring the sulfur gasified in the gasifier into the nitrogen and sulfur dioxide to make the sulfur Gas accounts for 15% of the molar fraction of the mixed atmosphere in the reaction system, nitrogen accounts for 70% of the molar fraction of the mixed atmosphere in the reaction system, and the gaseous sulfur and phosphogypsum are fully Contact reaction for 0.5 hours, the block obtained after the reaction is the calcium sulfide product, and the tail gas SO produced 2 For the production of sulfuric acid.

[0035] Calcium sulfide product composition analysis is as follows:

[0036] components

[0037] CaSO in phosphogypsu...

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Abstract

The invention discloses a method for preparing calcium sulfide by reducing and decomposting gypsum through sulfur, which is characterized in that: the method comprises the following steps: firstly, putting the gypsum into a reactor and raising the temperature to between 500 and 900DEG C for preheating 10 to 30 minutes at an inert atmosphere; and then introducing gaseous sulfur to perform reduction reaction with the gypsum for 0.5 to 2 hours to obtain a block, namely a calcium sulfide product, wherein the generated tail gas SO2 is used for producing sulphuric acid, and the gaseous sulfur accounts for 10 to 50 mol percent of mixed atmosphere in a reaction system. Because the method adopts a gas-solid reaction as a reaction mechanism, and the reaction is carried out at the inert atmosphere, the method has the advantages of low energy consumption, high reduction rate of over 95 percent, simple and mature process, short production period, easy control and convenient promotion.

Description

technical field [0001] The invention belongs to the technical field of preparing calcium sulfide from gypsum, and in particular relates to a method for preparing calcium sulfide by reducing and decomposing gypsum with sulfur. Background technique [0002] Calcium sulfide is a widely used chemical intermediate product, which can be used as a raw material for the production of chemical products such as thiourea, hydrogen sulfide, sulfur, or sulfuric acid. Although my country is a country lacking in sulfur resources, it needs to import a large amount of sulfur from abroad every year to produce sulfuric acid to meet the production needs of phosphate compound fertilizer manufacturers and other industries, but at the same time, my country has abundant gypsum resources, especially wet A large amount of waste phosphogypsum discharged from the industrial production of farphosphoric acid and phosphate fertilizer amounts to tens of millions of tons every year. The stacking of these pho...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B17/44C01B17/50
Inventor 杨秀山王辛龙张志业刘荆风余家鑫钟本和
Owner SICHUAN UNIV