A method for decomposing phosphogypsum to prepare silicon-calcium porous ceramsite and sulfuric acid

A siliceous, phosphogypsum technology, applied in chemical instruments and methods, sulfur compounds, inorganic chemistry, etc., can solve the problems of low utilization rate of tailings, and achieve the effects of low production cost, increased contact surface, and reduced energy consumption

Inactive Publication Date: 2017-09-22
WUHAN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] There are also patented technologies (CN201110097225.X, CN201410095622.7) that propose to use biomass raw materials and carbonized rice husks as reducing agents to decompose phosphogypsum to produce sulfuric acid, but none of the above-mentioned technologies utilize the tailings left by sulfuric acid with high added value, and there are tailings The problem of low utilization
And there is no report about the technology of preparing silicon-calcium porous ceramsite from the tailings of sulfuric acid produced by phosphogypsum

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] A method for decomposing phosphogypsum to prepare silicon-calcium porous ceramsite and sulfuric acid. Include the following steps:

[0021] Step 1. First, 60-70wt% of phosphogypsum and 30-40wt% of carbonized rice husk are used as raw materials, and mixed evenly to obtain a mixed fine powder.

[0022] Step 2. Stir 0.2-0.6 parts of sodium tripolyphosphate, 50-60 parts of water and 100 parts of the mixed fine powder evenly to prepare mud; then add 0.7- The foam made by 1.0 parts by mass of foaming agent and 1.0~2.0 parts by mass of binder are stirred evenly to prepare foam slurry.

[0023] Step 3: Add 50-100 parts of the mixed fine powder into the sugar-coating machine, then add the foam slurry prepared in step 2, adjust the speed of the sugar-coating machine to 40-50r / min, wet granulate, and make porous Pre-granulated.

[0024] Step 4: Baking the porous pre-granulated granules at 100-120°C for 6-12 hours, and then carrying out a catalytic decomposition reaction in a ni...

Embodiment 2

[0027] A method for decomposing phosphogypsum to prepare silicon-calcium porous ceramsite and sulfuric acid. This embodiment is the same as embodiment 1 except that the binding agent is silica sol.

Embodiment 3

[0029] A method for decomposing phosphogypsum to prepare silicon-calcium porous ceramsite and sulfuric acid. The present embodiment is the same as embodiment 1 except that the binding agent is boric acid.

[0030] In this example 1-3: the conversion rate of sulfur in phosphogypsum is 76~80wt%; the bulk density of the prepared lightweight calcium silicate brick is 0.6~0.8g / cm 3 , The cylinder compressive strength is 4.0~6.0MPa.

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Abstract

The invention discloses a method for preparing siliceous porous ceramsite and sulfuric acid by decomposing phosphogypsum. Using 60-90wt% of phosphogypsum and 10-40wt% of carbonized rice husks as raw materials, mixing evenly to prepare mixed fine powder; mix 100 parts by mass of mixed fine powder, 0.2-1.0 parts by mass of water reducing agent and 40-40 parts by mass of water reducing agent. 60 parts of water by mass to make mud; add foaming agent and binder to mud, stir evenly to obtain foam mud; add 50-200 parts of mixed fine powder into sugar coating machine, and then add all described foam slurry, wet granulation to obtain porous pre-granulation; baking, catalytic decomposition reaction is carried out under the conditions of nitrogen atmosphere and 800-1000 ℃ to obtain siliceous calcium porous ceramsite and sulfur dioxide gas; the obtained sulfur dioxide Sulfuric acid is obtained by oxidation and absorption. The invention has low production cost, low energy consumption and high sulfur conversion rate, and can efficiently utilize the tail slag to prepare siliceous porous ceramsite while preparing sulfuric acid; the prepared siliceous porous ceramsite has low bulk density and high cylinder compressive strength.

Description

technical field [0001] The invention belongs to the technical field of phosphogypsum treatment. Specifically relates to a method for decomposing phosphogypsum to prepare silicon-calcium porous ceramsite and sulfuric acid. Background technique [0002] Phosphogypsum is the main solid waste in my country's phosphate fertilizer industry, and its main component is dihydrate gypsum (CaSO 4 2H 2 O) and hemihydrate gypsum (CaSO 4 0.5H 2 o). According to incomplete statistics, the total annual discharge of phosphogypsum in my country exceeds 55 million tons (on a dry basis), and the cumulative stockpiles exceed 250 million tons. With the development of high-concentration phosphate fertilizers in China, the discharge of phosphogypsum will increase, which not only causes serious environmental pollution, but also becomes a major problem facing the sustainable development of the phosphorus chemical industry. Therefore, the effective treatment of phosphogypsum is urgent. [0003] ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B38/02C04B35/22C01B17/765
Inventor 方伟赵雷陈辉何漩辛兆鹏王鑫
Owner WUHAN UNIV OF SCI & TECH
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