Method for producing sulfuric acid and co-producing calcium carbide by phosphogypsum

A technology of phosphogypsum and calcium carbide, applied in chemical instruments and methods, sulfur compounds, inorganic chemistry, etc., can solve the problem of low comprehensive utilization rate of phosphogypsum, achieve good environmental protection and social benefits, reduce emissions, and solve comprehensive utilization problems Effect

Active Publication Date: 2012-05-09
CHINA PETROCHEMICAL CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] The purpose of the present invention is to solve the problem that the comprehensive utilization rate of existing phosp

Method used

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  • Method for producing sulfuric acid and co-producing calcium carbide by phosphogypsum
  • Method for producing sulfuric acid and co-producing calcium carbide by phosphogypsum

Examples

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Embodiment 1

[0033] Example 1. Taking the production line of 100,000 tons / year calcium carbide supporting 180,000 tons / year sulfuric acid production line as an example, the following figure 1 process flow. Enter the circulating fluidized bed decomposition furnace to purify phosphogypsum (dry basis) 32t / h, the temperature is 700℃; the air volume into the furnace is 18000m 3 / h, temperature 300°C, primary air volume 14400m 3 / h, secondary air volume 3600m 3 / h (secondary air accounts for 20.0% of the total air volume); the gas volume of the sealed calcium carbide furnace entering the furnace is 5600m 3 / h, the temperature is 700℃; the fuel coal into the furnace is 3.48t / h. The gas temperature out of the calciner is 1200°C, the decomposition rate of gypsum is 99.3%, and the composition of the furnace gas (dry basis) is SO 2 Volume fraction 14.65%, O 2 Volume fraction 10.06%, CO 2 Volume fraction 33.27%, N 2 The volume fraction is 42.02%. The amount of slag discharged from the calcine...

Embodiment 2

[0034] Example 2. Also take the 100,000 tons / year calcium carbide production line with 180,000 tons / year sulfuric acid production line as an example. figure 1 process flow. Enter the circulating fluidized bed decomposition furnace to purify phosphogypsum (dry basis) 32t / h, the temperature is 500℃; the air volume into the furnace is 20000m 3 / h, temperature 250°C, primary air volume 16000m 3 / h, secondary air volume 4000m 3 / h (secondary air accounts for 20.0% of the total air volume); the gas volume of the sealed calcium carbide furnace entering the furnace is 5600m 3 / h, the temperature is 650℃; the fuel coal into the furnace is 3.52t / h. The gas temperature out of the calciner is 1000°C, the gypsum decomposition rate is 99.1%, and the furnace gas component (dry basis) is SO 2 Volume fraction 13.82%, O 2 Volume fraction 9.60%, CO 2 Volume fraction 31.64%, N 2 The volume fraction is 44.94%. The amount of slag discharged from the calciner is 14.11t / h, of which the mass ...

Embodiment 3

[0035] Example 3. Also take the 100,000 tons / year calcium carbide production line with 180,000 tons / year sulfuric acid production line as an example. figure 1 process flow. Enter the circulating fluidized bed decomposition furnace to purify phosphogypsum (dry basis) 32t / h, the temperature is 400℃; the air volume into the furnace is 30000m 3 / h, temperature 250°C, primary air volume 20000m 3 / h, secondary air volume 5000m 3 / h (secondary air accounts for 20.0% of the total air volume); the gas volume of the sealed calcium carbide furnace entering the furnace is 5600m 3 / h, the temperature is 600℃; the fuel coal into the furnace is 3.7t / h. The temperature of the gas exiting the calciner is 950°C, the decomposition rate of gypsum is 99.0%, and the composition of the furnace gas (dry basis) is SO 2 Volume fraction 10.80%, O 2 Volume fraction 7.50%, CO 2 Volume fraction 30.00%, N 2 The volume fraction is 51.70%. The amount of slag discharged from the calciner is 14.13t / h, ...

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Abstract

The invention relates to a method for producing sulfuric acid and co-producing calcium carbide by phosphogypsum, and belongs to the technical field of environmental protection. According to the method, phosphogypsum is subjected to a water washing and purification pretreatment by a multi-stage cyclone; then the pretreated phosphogypsum is dried and dewatered; the dewatered phosphogypsum enters a multi-stage suspension heat exchanger to carry out preheating; the hot state gypsum enters a circulating fluidized bed decomposing furnace, then primary air and secondary air are respectively introduced to carry out decompositions; high temperature sulfur dioxide-containing flue gas discharged from the top of the circulating fluidized bed decomposing furnace enters the multi-stage suspension heat exchanger to carry out heat exchanging and cooling with the cold state gypsum; dust in the cooled hot flue gas is removed by a multi-stage dust removing device; the dust-removed flue gas enters an acid washing and purification system to further remove the dust and the gaseous impurities in the flue gas; the purified and cleaned flue gas is conveyed into an acid preparation system to produce the sulfuric acid product; the hot state calcium oxide discharged from the bottom of the circulating fluidized bed decomposing furnace is cooled, and conveyed into a sealed calcium carbide furnace to carry out an electrical arc reaction with a carbon material to generate the calcium carbide product; the high temperature furnace gas discharged from the top of the sealed calcium carbide furnace is directly conveyed into the decomposing furnace, wherein the high temperature furnace gas is adopted as a fuel and a reducing agent. The method of the present invention has good environmental protection benefits and strong economic advantages.

Description

technical field [0001] The invention belongs to the technical field of solid pollutant treatment and chemical production in environmental protection, and specifically relates to a method for producing sulfuric acid and co-producing calcium carbide from phosphogypsum. Background technique [0002] Phosphogypsum is the waste residue produced by the reaction between phosphate rock and sulfuric acid in the production process of wet-process phosphoric acid. According to the existing production process, 1 ton of phosphoric acid is produced as a by-product of 4~5 tons of phosphogypsum waste residue. According to the "Guiding Opinions of the Ministry of Industry and Information Technology on the Comprehensive Utilization of Industrial By-product Gypsum" issued in February 2011, the output of phosphogypsum in my country was about 50 million tons per year in 2009, and the cumulative stockpiled phosphogypsum in the country exceeded 200 million tons. At present, the comprehensive utiliz...

Claims

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Application Information

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IPC IPC(8): C01B17/74C01B31/32C01B32/942
CPCY02P20/129
Inventor 纪罗军黄新金苏闽胡小云王爱群
Owner CHINA PETROCHEMICAL CORP
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