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Method for directly preparing sulfur trioxide and sulfuric acid from plaster

A technology of sulfur trioxide and gypsum, applied in chemical instruments and methods, inorganic chemistry, sulfur compounds, etc., can solve problems such as complex process, large environmental pollution, and large investment

Active Publication Date: 2011-10-26
长沙紫宸科技开发有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing process is complex, large investment, high energy consumption, high operating cost, especially environmental pollution
However, the existing method for producing sulfur trioxide in the laboratory generally adopts pyrosulfate thermal decomposition method, which is difficult to control and difficult to produce in batches.

Method used

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  • Method for directly preparing sulfur trioxide and sulfuric acid from plaster
  • Method for directly preparing sulfur trioxide and sulfuric acid from plaster
  • Method for directly preparing sulfur trioxide and sulfuric acid from plaster

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Example 1: The laboratory uses a steam pressure of 4.0 MPa, a steam temperature of 350°C or 452°C, natural dihydrate gypsum and silica fume as raw materials, and nickel nitrate, potassium sulfate, and ferric oxide as catalyst activators. First, the dihydrate gypsum, silica fume and catalytic activator are ground together according to the ratio of 69.5% by mass: 30.4%: 0.1% or the ratio of 75%: 20%: 5%, to obtain a powder with 9.1% of the remaining 200 mesh sieve, and then Sulfuric acid is extracted by activation of steam medium. The content of sulfuric acid in the stable extract in the middle of the analysis was 17.3%, 17.6%, and sulfurous acid was not detected. Sulfur trioxide is 0.3% and 2.7% in the chemical analysis of the solid residue after extraction, and the main mineral is hydrated calcium silicate according to the diffraction analysis.

Embodiment 2

[0022] Example 2: Small-scale test, using a supercritical boiler to reheat steam at a temperature of 720°C and a pressure of 28.6MPa. The raw materials are desulfurized gypsum and silica sand, and catalytic activators such as potassium hydroxide, vanadium pentoxide, cesium sulfate, etc., and the desulfurized gypsum is first dried Roast to anhydrous gypsum, then grind gypsum, silica sand, and catalytic activator according to the mass percentage of 30%: 69%: 1% together until 8.7% of the powder remains on a 200-mesh sieve, and then use steam medium to activate and extract sulfuric acid. The content of sulfuric acid in the stable extract was analyzed to be 21.7%, and sulfurous acid was not detected. The sulfur trioxide content of the solid residue after extraction is 1.8% according to chemical analysis, and the main mineral is wollastonite according to diffraction analysis.

Embodiment 3

[0023] Embodiment 3: The laboratory uses an electric furnace, and the temperature is controlled at 500°C to 780°C or 780°C to 1300°C for activation. The raw materials are natural anhydrite and silica, and the catalytic activator is potassium carbonate, cerium oxide, ferric oxide and / or or potassium sulfate. First, anhydrite, silica, and catalytic activator are mixed according to the mass percentage of 65%: 34%: 1%, and then ground together until the remaining 3.4% of the 200-mesh sieve is obtained. As a semi-solid, the analytical composition is sulfur trioxide 98.7%, the solid residue after extraction contains 3.3% sulfur trioxide according to chemical analysis, and the main component is wollastonite according to diffraction analysis.

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Abstract

The invention discloses a method for directly preparing sulfur trioxide and a sulfuric acid from plaster. The method is characterized in that: the sulfur trioxide is directly displaced from the plaster with silicon dioxide by using thermal activation or photon activation assisted by catalytic activation and suppressing reducing atmosphere, and the sulfur trioxide serving as a reaction product is timely removed, wherein an elementary equation is that the sulfuric acid product can be prepared from the extracted sulfur trioxide serving as the reaction product by conventional mature known acid making technology. As the sulfur trioxide and the sulfuric acid are directly prepared from the plaster, the method is energy-saving, environment-friendly and effective; and as the sulfur resource in theplaster is utilized to produce basic chemical raw materials, namely the sulfur trioxide and the sulfuric acid, the method has the advantage of completely changing the energy-consuming and contaminative conventional out-dated process method in which sulfur dioxide is necessarily first prepared and then converted into sulfur trioxide by high temperature catalytic oxidation during the preparation of the sulfuric acid.

Description

Technical field: [0001] The invention relates to an acid production method in the chemical industry, in particular to a method for directly producing sulfur trioxide and sulfuric acid from gypsum. Background technique: [0002] Sulfur trioxide and sulfuric acid are important basic chemical raw materials. The existing sulfuric acid production process is to produce sulfur dioxide by burning sulfur or roasting pyrite or decomposing gypsum in a reducing atmosphere to produce sulfur dioxide, and then oxidize the sulfur dioxide to sulfur trioxide under high temperature conditions of the catalyst to produce sulfuric acid or sulphur trioxide. The existing process is complex, with large investment, high energy consumption, high operating cost, and especially large environmental pollution. However, the existing method for producing sulfur trioxide in the laboratory generally adopts pyrosulfate thermal decomposition method, which is difficult to control and difficult to produce in ba...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B17/74
Inventor 尹小林
Owner 长沙紫宸科技开发有限公司