Coproducing cement technological method of producing acid using phosphogypsum and sulfur

Abstract

The present invention relates to a process capable of simultaneously preparing acid and producing cement by combining phosphogypsum with sulfur. It is characterized by utilizing waste slag phosphogypsum obtained by wet process phosphoric acid production to prepare acid and produce cement. In the concrete, the invented process includes the following steps: utilizing low-concentration SO2 gas discharged out from rotary kiln of phosphogypsum acid-making system and making said kiln gas undergo the processes of washing, cleaning and drying, then be mixed with high-concentration SO2 gas discharged from sulfur acid-making system to obtain the SO2 gas whose concentration is 8-9%; and adopting an advanced two-stage two-absorption acid-making process to prepare sulfuric acid; at the same time firing the phosphogypsum in the rotary kiln to obtain cement clinker, grinding and blending so as to obtain cement.

Description

Technical field:

[0001] The present invention relates to a process method for combining phosphogypsum and sulfur to produce acid and co-produce cement. It uses wet-process phosphoric acid to produce waste residue phosphogypsum to produce cement sulfuric acid. Specifically, it refers to the use of phosphogypsum acid system to produce low-concentration SO from a rotary kiln. 2 Gas, the kiln gas is washed, purified and dried, and the high concentration SO 2 The gas is mixed to form SO with a concentration of 8-9% by volume 2 The gas is made into sulfuric acid by the advanced two-turn-two-suction acid production process, and at the same time, phosphogypsum is fired into cement clinker in a rotary kiln, and then cement is made into cement through grinding and batching. Background technique:

[0002] The main component of waste phosphogypsum produced by wet-process phosphoric acid production is CaSO 4. 2H 2 O, is currently mainly used to produce cement and produce sulfuric acid...

Examples

Embodiment 1

[0048] After reslurry washing and purification, free P 2 o 5 The phosphogypsum is 0.65% and the F content is 0.21%. It is sent to the dehydrator to dehydrate and remove the washing water, and then enters the dryer for drying. After cooling, it enters the batching bin. Anthracite, silica and kaolin are ground by an air-swept ball mill to reach a particle size of -200 mesh sieve between 10 and 12%, and enter the batching bin through blasting to homogenize the prepared cement raw materials. The homogenized raw meal is put into the rotary kiln for calcination, and the decomposition section of the rotary kiln is controlled at 1280-1335°C through coal injection gun and air volume adjustment, and the carbon in the anthracite in the kiln reduces phosphogypsum to CaO and SO 2 , the CaO in the material is in the sintering section at 1430-1480 ° C, and the mineralization reaction occurs with the silica to survive the dicalcium silicate (C 2 S) and tricalcium silicate (C 3 S) The reac...

Embodiment 2

[0055] After reslurry washing and purification, free P 2 o 5 The phosphogypsum is 0.96% and the F content is 0.33%. It is sent to the dehydrator to dehydrate and remove the washing water, and then enters the dryer for drying. After cooling, it enters the batching bin. Anthracite, silica and kaolin are ground by an air-swept ball mill to reach a particle size of -200 mesh sieve between 10 and 12%, and enter the batching bin through blasting to homogenize the prepared cement raw materials. The homogenized raw meal is put into the rotary kiln for calcination, and the decomposition section of the rotary kiln is controlled at 1280-1335°C through coal injection gun and air volume adjustment, and the carbon in the anthracite in the kiln reduces phosphogypsum to CaO and SO 2 , the CaO in the material is in the sintering section at 1430-1480 ° C, and the mineralization reaction occurs with the silica to survive the dicalcium silicate (C 2 S) and tricalcium silicate (C 3 S) The reac...

Technical field:

[0001] The present invention relates to a process method for combining phosphogypsum and sulfur to produce acid and co-produce cement. It uses wet-process phosphoric acid to produce waste residue phosphogypsum to produce cement sulfuric acid. Specifically, it refers to the use of phosphogypsum acid system to produce low-concentration SO from a rotary kiln. 2 Gas, the kiln gas is washed, purified and dried, and the high concentration SO 2 The gas is mixed to form SO with a concentration of 8-9% by volume 2 The gas is made into sulfuric acid by the advanced two-turn-two-suction acid production process, and at the same time, phosphogypsum is fired into cement clinker in a rotary kiln, and then cement is made into cement through grinding and batching. Background technique:

[0002] The main component of waste phosphogypsum produced by wet-process phosphoric acid production is CaSO 4. 2H 2 O, is currently mainly used to produce cement and produce sulfuric acid...

Examples

Embodiment 1

[0048] After reslurry washing and purification, free P 2 o 5 The phosphogypsum is 0.65% and the F content is 0.21%. It is sent to the dehydrator to dehydrate and remove the washing water, and then enters the dryer for drying. After cooling, it enters the batching bin. Anthracite, silica and kaolin are ground by an air-swept ball mill to reach a particle size of -200 mesh sieve between 10 and 12%, and enter the batching bin through blasting to homogenize the prepared cement raw materials. The homogenized raw meal is put into the rotary kiln for calcination, and the decomposition section of the rotary kiln is controlled at 1280-1335°C through coal injection gun and air volume adjustment, and the carbon in the anthracite in the kiln reduces phosphogypsum to CaO and SO 2 , the CaO in the material is in the sintering section at 1430-1480 ° C, and the mineralization reaction occurs with the silica to survive the dicalcium silicate (C 2 S) and tricalcium silicate (C 3 S) The reac...

Embodiment 2

[0055] After reslurry washing and purification, free P 2 o 5 The phosphogypsum is 0.96% and the F content is 0.33%. It is sent to the dehydrator to dehydrate and remove the washing water, and then enters the dryer for drying. After cooling, it enters the batching bin. Anthracite, silica and kaolin are ground by an air-swept ball mill to reach a particle size of -200 mesh sieve between 10 and 12%, and enter the batching bin through blasting to homogenize the prepared cement raw materials. The homogenized raw meal is put into the rotary kiln for calcination, and the decomposition section of the rotary kiln is controlled at 1280-1335°C through coal injection gun and air volume adjustment, and the carbon in the anthracite in the kiln reduces phosphogypsum to CaO and SO 2 , the CaO in the material is in the sintering section at 1430-1480 ° C, and the mineralization reaction occurs with the silica to survive the dicalcium silicate (C 2 S) and tricalcium silicate (C 3 S) The reac...

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