Method for reducing and decomposing phosphogypsum by sulfur

A phosphogypsum and sulfur technology, applied in chemical instruments and methods, sulfur compounds, inorganic chemistry, etc., can solve the problems of high reaction temperature, increased energy consumption, cumbersome process, etc., and achieve reduced reaction energy consumption, high reduction rate, and energy saving The effect of energy consumption

Active Publication Date: 2010-05-19
SICHUAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Although the above method of reducing and decomposing phosphogypsum to produce sulfuric acid co-production cement has made full use of prohibited substances and wastes in the coal industry to reduce and decompose phosphogypsum, and the decomposition rate and desulfurization rate are relatively high, but there are some or other defects to varying degrees. Problem: Since the traditional reaction mechanism of reduci...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Raw material 1: Phosphogypsum powder.

[0022] The composition of phosphogypsum powder is shown in the table below, and the collection point is the phosphogypsum slag yard of Sichuan Gaoyu Group.

[0023] components

SiO 2

Fe 2 o 3

Al 2 o 3

CaO

MgO

SO 3

P 2 o 5

F

Loss on ignition

total

content%

6.66

0.40

0.30

34.84

0.08

34.80

1.19

0.070

20.96

99.30

[0024] Raw material 2: Sulfur (content 99.50%)

[0025] The method is to first put 5000g of phosphogypsum powder into a quartz tubular reactor and heat it up to 900°C for 10 minutes under a nitrogen atmosphere, and then bring the sulfur gasified in the gasifier into the nitrogen gas to make the sulfur gas The mole fraction of the mixed atmosphere in the reaction system is 15%, and after the gaseous sulfur and phosphogypsum powder are fully contacted and reacted for 1 hour under the condition that...

Embodiment 2

[0027] Raw material is with embodiment 1, omission.

[0028] The method is to first put 4000g of phosphogypsum powder into a quartz tube reactor and 2 Under atmosphere, warm up to 700°C for 30 minutes, and then 2 Bring in the sulfur gasified in the gasifier, so that the sulfur gas accounts for 35% of the molar fraction of the mixed atmosphere in the reaction system, and make the gaseous sulfur and phosphogypsum powder fully After 1.5 hours of contact reaction, the obtained calcium sulfide block was ground and then mixed with the active ingredient CaSO in phosphogypsum 4 Mix evenly at a molar ratio of 1.3:3, and N in a vacuum tube reactor 2 and SO 2 Atmosphere (N 2 The mole fraction is 75%), roasted at 1200°C for 1.5 hours, and the obtained solid slag has a CaO mass percentage content of 75.0% after determination, and can be used as cement clinker for cement production. generated SO 2 The tail gas returns to the first section, and the tail gas SO produced by the first sec...

Embodiment 3

[0030] Raw material is with embodiment 1, omission.

[0031] The method is to first put 2000g of phosphogypsum powder into a quartz tube reactor and 2 Under atmosphere, warm up to 500°C for 30 minutes, and then 2 Bring in the sulfur gasified in the gasifier, so that the sulfur gas accounts for 50% of the molar fraction of the mixed atmosphere in the reaction system, and make the gaseous sulfur and phosphogypsum powder fully After 2 hours of contact reaction, the obtained calcium sulfide block was ground and then mixed with the active ingredient CaSO in phosphogypsum 4 Mix evenly at a molar ratio of 1.5:3, and N in a vacuum tube reactor 2 and CO atmosphere (N 2 The mole fraction is 80%), roasted at 1300° C. for 1 hour, and the obtained solid slag has a CaO mass percentage content of 75.2% after determination, and can be used as cement clinker for cement production. generated SO 2 The tail gas returns to the first section, and the tail gas SO produced by the first section ...

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Abstract

The invention discloses a method for reducing and decomposing phosphogypsum by sulfur, which comprises the following steps: putting the phosphogypsum into a reactor, and raising the temperature to between 500 and 900DEGC for preheating for 10 to 30 minutes at an inert atmosphere; introducing gaseous sulfur in a molar percentage of 10 to 50 percent to perform reduction reaction with the phosphogypsum for 1 to 2 hours; grinding obtained a calcium sulfide block, and uniformly mixing the ground calcium sulfide with the phosphogypsum in a molar ratio of 1-1.5:3; sintering at a temperature between 1,000 and 1,400 DEG C for 0.5 to 3 hours at a non-oxidizing atmosphere; and taking CaO in the obtained solid slag as a cement clinker for cement production, taking the generated tail gas SO2 as a raw material gas for producing sulphuric acid. The reduction rate of CaSO4 is high, the decomposition ratio of the phosphogypsum can reach over 98 weight percent, the desulfurization ratio of the phosphogypsum can reach over 95 weight percent, and the method has the advantages of low energy consumption, simple and mature process, short production period, easy control and convenient promotion.

Description

technical field [0001] The invention belongs to the technical field of reducing and decomposing phosphogypsum, and in particular relates to a method for reducing and decomposing phosphogypsum with sulfur. Background technique [0002] Phosphogypsum is the solid waste discharged during the production of wet-process phosphoric acid. Generally speaking, about 5-6 tons of phosphogypsum is produced for every 1 ton of phosphoric acid produced, and the actual amount is about 7.5 tons. The concentration of phosphorus compound fertilizer increased significantly. However, the current resource utilization of phosphogypsum is not satisfactory. It is known that the effective utilization rate of phosphogypsum in the world is only about 4.5%. By the end of the "Eleventh Five-Year Plan", the annual discharge of phosphogypsum in my country will exceed 50 million tons, and the cumulative stockpiles have exceeded 120 million tons. Stacking phosphogypsum not only takes up a lot of land, but a...

Claims

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Application Information

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IPC IPC(8): C01B17/50C04B7/34C01B17/74
Inventor 杨秀山张志业王辛龙房广宇钟本和
Owner SICHUAN UNIV
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