Method for fluidized catalytic decomposition of gypsum

A fluidized catalysis, gypsum technology, applied in chemical instruments and methods, inorganic chemistry, phosphorus compounds, etc., can solve the problems of high energy consumption, low product added value, slow decomposition rate, etc. The effect of high value and fast decomposition rate

Inactive Publication Date: 2015-06-24
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the current gypsum decomposition technology still has the following problems: high energy consumption for gypsum decomposition, slow decomposition rate, low added value of products, environmental pollution, and backward technology
[0007] The above-mentioned technical solutions have made certain contributions in solving the problems of high decomposition energy consumption, slow decomposition rate, environmental pollution, and backward technology of gypsum decomposition technology, but they are not comprehensive, and all of them have low added value of products, which cannot make the technical solutions obtain good economic benefits. Shortcomings

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  • Method for fluidized catalytic decomposition of gypsum

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (1), powdered natural gypsum or anhydrite raw material and iron or scandium oxide molecular sieve catalyst particles are mixed evenly according to the mass ratio of 1:1, and then added to the fluidized reactor;

[0029] (2) Sulfur gas after sulfur gasification of the reducing agent enters from the bottom of the fluidized reactor at a mass ratio of 2:1 to gypsum powder and a mole fraction of the gas phase of 10%, and contacts with the material in (1), at 550°C To decompose gypsum, the residence time of the material is 1min, and the decomposition rate of gypsum is 60%.

[0030] (3), the solid phase obtained by the fluidized catalytic decomposition reaction (calcium sulfide mass fraction is 40% powder and catalyst particles) is steam washed, and the solid phase after washing is a metal oxide molecular sieve catalyst, after drying at 120 ° C Return to step (1) for recycling. The gas phase is first condensed to obtain a suspension with a mass fraction of calcium hydroxide o...

Embodiment 2

[0033] (1), powdery desulfurization gypsum or salt gypsum raw material and titanium or manganese oxide molecular sieve catalyst particles are mixed evenly according to the mass ratio of 10:1, and then added to the fluidized reactor;

[0034] (2) Sulfur gas after gasification of sulfur as a reducing agent enters from the bottom of the fluidized reactor at a mass ratio of 3:1 to gypsum powder and a mole fraction of the gas phase of 40%, and contacts with the material in (1), at 600°C Decompose gypsum, the material residence time is 10min, and the gypsum decomposition rate is 80%.

[0035] (3), the solid phase obtained by the fluidized catalytic decomposition reaction (calcium sulfide mass fraction is 70% powder and catalyst particles) is steam washed, and the solid phase after washing is a metal oxide molecular sieve catalyst, after drying at 150 ° C Return to step (1) for recycling. The gas phase is first condensed to obtain a suspension with a mass fraction of calcium hydroxi...

Embodiment 3

[0038] (1), powdery titanium dioxide by-product gypsum raw material and vanadium or chromium oxide molecular sieve catalyst particles are mixed evenly according to the mass ratio of 5:1, and added to the fluidized reactor;

[0039] (2) Sulfur gas after sulfur gasification of the reducing agent enters from the bottom of the fluidized reactor at a mass ratio of 6:1 to gypsum powder and a mole fraction of the gas phase of 50%, and contacts with the material in (1), at 620°C Decompose gypsum, the material residence time is 20min, and the gypsum decomposition rate is 90%.

[0040] (3), the solid phase obtained by the fluidized catalytic decomposition reaction (calcium sulfide mass fraction is 95% powder and catalyst particles) is steam washed, and the solid phase after washing is a metal oxide molecular sieve catalyst, after drying at 180 ° C Return to step (1) for recycling. The gas phase is first condensed to obtain a suspension with a mass fraction of calcium hydroxide of 45%, ...

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Abstract

The invention discloses a method for fluidized catalytic decomposition of gypsum. The method comprises the following steps: mixing gypsum with a metal oxide molecular sieve catalyst evenly, and adding to a fluidized reactor; feeding a sulphur gas from the bottom of the fluidized reactor, enabling the sulphur gas with a solid material, and reacting for decomposing the gypsum; washing a solid phase obtained by reaction with steam, wherein the washed solid phase is the metal oxide molecular sieve catalyst; drying and using in cycle; condensing the washed gas phase to obtain a Ca(OH)2 turbid liquid for preparation of a calcium salt; preparing sulphur employing individual uncondensed gas phase or SO2 in a gas-phase product obtained by decomposition reaction of the uncondensed gas phase and the gypsum according to claus reaction, and using the sulphur as a reducing agent in cycle; carrying out dust removal on the gas phase obtained by decomposition reaction of the gypsum, cooling and separating to obtain insoluble sulphur; and using the soluble sulphur as the reducing agent in cycle, and preparing the sulphur from the residual gas phase and H2S for cyclic use as the reducing agent or production of sulfuric acid. The gypsum decomposition is low in energy consumption and high in decomposition rate; the additional value of the product is high; and the process is environment-friendly and advanced.

Description

technical field [0001] The invention relates to the technical field of utilization of gypsum resources, in particular to a method for fluidized catalytic decomposition of gypsum. Background technique [0002] my country has abundant natural gypsum resources and various industrial by-product gypsum resources piled up in huge quantities. At the same time, my country is facing the resource dilemma of lack of sulfur resources and calcium oxide resources mainly using limestone as raw material. my country's sulfur resource industry, especially the production of sulfuric acid, relies heavily on imported sulfur from abroad, making the development of the entire industry subject to others and full of risks. However, obtaining calcium oxide resources by calcining limestone also emits a large amount of greenhouse gas carbon dioxide, which seriously deviates from the current environmental protection trend of energy conservation and emission reduction. Decomposing gypsum to obtain sulfur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B17/12C01B17/69C01F11/18C01F11/36C01F11/24C01B25/32
CPCY02P20/584C01B17/12C01B17/69C01B25/322C01F11/18C01F11/24C01F11/36C01P2006/80
Inventor 杨秀山孔行健张志业王辛龙杨林钟本和
Owner SICHUAN UNIV
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