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Decomposition method of ardealite

A phosphogypsum and sieving technology, which is applied in chemical instruments and methods, inorganic chemistry, calcium/strontium/barium oxide/hydroxide, etc., can solve the problem of high reaction temperature, low CaO yield and the influence of phosphogypsum on sulfuric acid production Issues such as the large-scale promotion of the co-production cement process, etc., to achieve the effect of simple process, improved economy, and inhibited the formation of CaS

Inactive Publication Date: 2015-07-22
KUNMING UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] At present, the published patents for the production of sulfuric acid from phosphogypsum have problems such as high reaction temperature, mostly at 1000°C and above, and low CaO yield, which affect the large-scale promotion of the process of producing sulfuric acid from phosphogypsum for co-production of cement

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  • Decomposition method of ardealite
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  • Decomposition method of ardealite

Examples

Experimental program
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Effect test

Embodiment 1

[0033] (1) Phosphogypsum is naturally air-dried, crushed, ground, and sieved to obtain phosphogypsum powder with a particle size of 100 mesh;

[0034] (2) impregnate 50g of phosphogypsum powder obtained in step (1) into 2 (SO 4 ) 3 and NiSO 4 Soluble in water to prepare the impregnating liquid, the concentration of ferric ion in the impregnating liquid is 1.0mol / L, the concentration of divalent nickel ion is 1.0mol / L, stir for 12h, filter and take out the filter residue, at 100℃ Next, dry for 2 hours, after removing the free water, get the pretreated phosphogypsum;

[0035] (3) Put 20g of pretreated phosphogypsum in an inert atmosphere first, then calcinate at 570°C for 60min, and at the same time pass in CO gas with a purity of 95%, the CO gas and CaSO in phosphogypsum 4 The molar ratio is 1:3, and real-time monitoring of SO with flue gas analyzer 2 Concentration, after the reaction is completed, cool naturally to room temperature, and measure S in the residue by iodomet...

Embodiment 2

[0039](1) Phosphogypsum is naturally air-dried, crushed, ground, and sieved to obtain phosphogypsum powder with a particle size of 110 mesh;

[0040] (2) 50g of phosphogypsum powder obtained in step (1) was impregnated with FeCl 3 and Ni(NO 3 ) 2 Soluble in water to prepare the impregnation solution, the concentration of ferric ion in the impregnation solution is 0.8mol / L, the concentration of divalent nickel ion is 0.5mol / L, stir for 8h, filter and take out the filter residue, at a temperature of 110℃ Next, dry for 1.5h, after removing the free water, get the pretreated phosphogypsum;

[0041] (3) Put 20g of pretreated phosphogypsum in an inert atmosphere first, then calcinate at 590°C for 30min, and at the same time pass in CO gas with a purity of 98%, the CO gas and CaSO in phosphogypsum 4 The molar ratio is 1:5, and real-time monitoring of SO with flue gas analyzer 2 Concentration, after the reaction is completed, cool naturally to room temperature, and measure S in th...

Embodiment 3

[0045] (1) Phosphogypsum is naturally air-dried, crushed, ground, and sieved to obtain phosphogypsum powder with a particle size of 110 mesh;

[0046] (2) Immerse 50g of phosphogypsum powder obtained in step (1) in 3 ) 3 and NiCl 2 Soluble in water to prepare the impregnating solution, the concentration of ferric ion in the impregnating solution is 0.5mol / L, the concentration of divalent nickel ion is 0.9mol / L, stir for 10h, filter and take out the filter residue, at a temperature of 120℃ Next, dry for 1 hour, after removing the free water, get the pretreated phosphogypsum;

[0047] (3) Place 20g of pretreated phosphogypsum in an inert atmosphere, and then calcinate at 610°C for 40min, while passing in CO gas with a purity of 99.9%, the CO gas and CaSO in phosphogypsum 4 The molar ratio is 1:4, and real-time monitoring of SO with flue gas analyzer 2 Concentration, after the reaction is completed, cool naturally to room temperature, and measure S in the residue by iodometri...

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Abstract

The invention discloses a method for decomposing phosphogypsum, which belongs to the technical field of phosphorus chemical treatment. The phosphogypsum is placed in an impregnating liquid containing ferric iron ions and divalent nickel ions, and Fe-Ni composite catalysis is used to reduce the decomposition temperature of phosphogypsum to 570°C. ℃-630℃, a certain amount of CO gas is introduced to form a weak reducing atmosphere, which improves the CO reduction selectivity, obtains more CaO, further suppresses the generation of CaS, and simultaneously obtains the raw material gas SO2 for sulfuric acid production.

Description

technical field [0001] The invention relates to a method for decomposing phosphogypsum, which belongs to the technical field of phosphorus chemical treatment. Background technique [0002] Phosphogypsum is an industrial waste residue produced during the production of phosphoric acid, and its main component is CaSO 4 , with the rapid development of high-concentration phosphorus compound fertilizer, phosphoric acid and detergent industries, phosphogypsum residues have increased sharply, and about 5 tons of phosphogypsum are discharged for every 1 ton of phosphoric acid produced. In 2004, the world's annual discharge of phosphogypsum reached 280 million tons. my country's phosphogypsum discharge has reached 30 million t / a, and Yunnan Province alone has reached 10 million t / a. As the world's largest producer of phosphate fertilizer, China is also the largest by-product of phosphogypsum. The production process of wet-process phosphoric acid Among them, every 1 ton of phosphoric ac...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01F11/04C01B17/50
Inventor 马丽萍闫贝谢龙贵资泽成马俊
Owner KUNMING UNIV OF SCI & TECH