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Method for producing cement and sulfuric acid by calcining anhydrite

A technology of anhydrite and cement, which is applied in chemical instruments and methods, cement production, sulfur compounds, etc., can solve problems such as no major breakthroughs, and achieve the effects of cost reduction, high conversion rate, and energy saving

Inactive Publication Date: 2012-07-18
刘立文
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, for a long time, my country has not made much breakthrough in the process of preparing cement and sulfuric acid from gypsum.

Method used

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  • Method for producing cement and sulfuric acid by calcining anhydrite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] This embodiment includes the following steps:

[0022] (1) Crush the anhydrite, and control the mass fraction of the crushed anhydrite 10mm sieve to 18%; dry it to generate hemihydrate gypsum, and control the moisture content of the hemihydrate gypsum to 8%;

[0023] (2) Mix barite, sand, coal and the hemihydrate gypsum obtained in step (1), place in the preheater, heat to 850-900°C, and then add the raw materials preheated by the preheater to the rotary kiln, Heating to 1240°C and keeping it warm for 3 hours, through chemical reaction, high-temperature kiln gas and solid materials containing sulfur dioxide are obtained, and the high-temperature kiln gas is introduced into the preheater for preheating raw materials, while reducing the temperature of the kiln gas;

[0024] The mass percentages of the hemihydrate gypsum, barite, sand and coal are: 50% of hemihydrate gypsum, 30% of barite, 15% of sand and 5% of coal;

[0025] (3) Cool the solid material obtained in step (...

Embodiment 2

[0030] This embodiment includes the following steps:

[0031] (1) Crush the anhydrite, and control the mass fraction of the 10mm sieve of the crushed anhydrite to be 12%; dry to generate hemihydrate gypsum, and control the moisture content of the hemihydrate gypsum to 7%;

[0032] (2) Mix barite, sand, coal and the hemihydrate gypsum obtained in step (1), place in a preheater, heat to 900-950°C, and then feed the raw materials preheated by the preheater into the rotary kiln, Heating to 1000°C, keeping it warm for 2 hours, through chemical reaction, high-temperature kiln gas and solid materials containing sulfur dioxide are obtained, and the high-temperature kiln gas is introduced into the preheater to preheat the raw materials, while reducing the temperature of the kiln gas;

[0033] The mass percent of described hemihydrate gypsum, barite, sand and coal is: hemihydrate gypsum 40%, barite 50%, sand 5%, coal 5%;

[0034] (3) Cool the solid material obtained in step (2) to a te...

Embodiment 3

[0039] This embodiment includes the following steps:

[0040] (1) Crush the anhydrite, and control the mass fraction of the crushed anhydrite 10mm sieve to 16%; dry it to generate hemihydrate gypsum, and control the moisture content of the hemihydrate gypsum to 8%;

[0041] (2) Mix barite, sand, coal and the hemihydrate gypsum obtained in step (1), place in the preheater, heat to 850-900°C, and then send the preheated raw materials into the rotary kiln , heated to 1450°C, kept for 5 hours, through chemical reaction, high-temperature kiln gas and solid materials containing sulfur dioxide were obtained, and the high-temperature kiln gas was introduced into the preheater for preheating raw materials, while reducing the temperature of the kiln gas;

[0042] The mass percentages of the hemihydrate gypsum, barite, sand and coal are: 70% of hemihydrate gypsum, 20% of barite, 5% of sand and 5% of coal;

[0043] (3) Cool the solid material obtained in step (2) to a temperature of 90°C...

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Abstract

A method for producing cement and sulfuric acid by calcining anhydrite comprises the following steps: firstly, crushing and drying the anhydrite to obtain hemihydrate gypsum; secondly, mixing the obtained hemihydrate gypsum, barite, sandy soil and coal, feeding the mixture in a preheater, heating the mixture until the temperature reaches 850 to 950DEG C, feeding the heated mixture in a rotary kiln, heating the mixture until the temperature reaches 1000 to 1450DEG C and maintaining the temperature for 2-5 hours to obtain kiln gas and solid materials; feeding the obtained kiln gal into a preheater for preheating raw materials and reducing the temperature of the kiln gas at the same time; thirdly, cooling the obtained solid materials to 30-90DEG C, feeding a cement retarder and grinding to obtain a cement product; and fourthly, collecting kiln gas from the preheater and the rotary kiln, removing dust, purifying and drying, oxidizing sulfur dioxide in the kiln gas into sulfur trioxide under the action of an alum catalyst, and absorbing and converting the sulfur trioxide with more than or equal to 98 percent concentrated sulfuric acid to generate the sulfuric acid. The cement produced by the method disclosed by the invention contains barium, has high density and radiation resistance and is especially suitable for nuclear power plant engineering or buildings of blindages and air-raid shelters.

Description

technical field [0001] The invention relates to a method for producing cement and sulfuric acid, in particular to a method for producing cement and sulfuric acid by calcining anhydrite. Background technique [0002] The technology of preparing sulfuric acid and cement from gypsum began in the early 20th century. In 1916, Germany developed the technology of preparing sulfuric acid and cement from natural gypsum. After that, Britain, France, Poland and other countries successively built natural gypsum, anhydrite and phosphogypsum. Factories that produce cement from raw materials have closed down one after another due to low productivity and inadequate technology. [0003] Later, due to the mass production of phosphate fertilizers, etc., the technology of preparing cement from phosphogypsum began to develop rapidly, and some key technologies were broken through. [0004] However, for a long time, my country has not made much breakthrough in the process of preparing cement and ...

Claims

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Application Information

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IPC IPC(8): C01B17/74C04B7/24
CPCY02P40/10
Inventor 刘立文刘四海宁勇鲁纪鸣
Owner 刘立文
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