Low-temperature phosphogypsum decomposition method

A phosphogypsum and low-temperature technology, applied in the field of low-temperature decomposition of phosphogypsum, and reducing the decomposition temperature of phosphogypsum during the decomposition process of phosphogypsum, can solve the problems of waste of land resources and sulfur-calcium resources, complex components of decomposition products, complex additive components, etc., to achieve Effect of increasing content, low price, and reducing energy consumption

Inactive Publication Date: 2013-06-05
KUNMING UNIV OF SCI & TECH
View PDF5 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, my country has stockpiled 200 million tons, but the utilization rate is less than 10%, and the rest are directly stacked in the open air, which not only causes a lot of waste of land resources and sulfur-calcium resources, but also causes serious environmental

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Low-temperature phosphogypsum decomposition method
  • Low-temperature phosphogypsum decomposition method
  • Low-temperature phosphogypsum decomposition method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Embodiment 1: the method for this low-temperature decomposition of phosphogypsum, the specific content is as follows:

[0022] (1) The main chemical components of the phosphogypsum raw materials used in this example are: calcium oxide 35.36%, sulfur dioxide 47.12%, iron oxide 3.01%, aluminum oxide 2.05%, phosphorus pentoxide 1.20%, fluorine 0.06%, silicon dioxide 11.20% %;

[0023] (2) Crushing and grinding the dried phosphogypsum raw material, and sieving to a particle size between 0.074-0.150mm;

[0024] (3) Mix phosphogypsum with a mass percentage of 86% and calcium chloride with a mass percentage of 14% (particle size less than 0.074mm), stir evenly, then dry the mixture at 100°C for 6 hours and put it in a tube furnace. Heating to 650°C at a heating rate of 10°C / min, while introducing hydrogen sulfide gas (5% concentration by volume) at a gas rate of 300mL / min, the carrier gas is nitrogen, and keeping at 650°C for 45 minutes. The gas analyzer measures the content...

Embodiment 2

[0027] Embodiment 2: the method for this low-temperature decomposition of phosphogypsum, the specific content is as follows:

[0028] (1) The main chemical components of phosphogypsum used in this example are: calcium oxide 35.36%, sulfur dioxide 47.12%, iron oxide 3.01%, aluminum oxide 2.05%, phosphorus pentoxide 1.20%, fluorine 0.06%, silicon dioxide 11.20%;

[0029] (2) Crushing and grinding the dried phosphogypsum raw material, and sieving to a particle size between 0.074-0.150mm;

[0030] (3) Mix phosphogypsum with a mass percentage of 71% and calcium chloride with a mass percentage of 29% (particle size less than 0.074mm), stir evenly, then dry the mixture at 125°C for 3 hours and put it into a tube furnace. Heating to 700°C at a heating rate of 15°C / min, while introducing hydrogen sulfide gas (volume percentage concentration: 10%) at a gas velocity of 150mL / min, the carrier gas is nitrogen, and keeping at 700°C for 30 minutes. The gas analyzer measures the content of ...

Embodiment 3

[0033] Embodiment 3: the method for this low-temperature decomposition of phosphogypsum, the specific content is as follows:

[0034] (1) The main chemical components of phosphogypsum used in this example are: calcium oxide 35.36%, sulfur dioxide 47.12%, iron oxide 3.01%, aluminum oxide 2.05%, phosphorus pentoxide 1.20%, fluorine 0.06%, silicon dioxide 11.20%;

[0035] (2) Crushing and grinding the dried phosphogypsum raw material, and sieving to a particle size of 0.074-0.150mm;

[0036](3) Mix 80% by mass phosphogypsum and 20% by mass calcium chloride (particle size less than 0.074mm), stir well, then dry the mixture at 110°C for 4 hours and put it into a tube furnace. Heating to 675°C at a heating rate of 5°C / min, while introducing hydrogen sulfide gas (3% volume percent concentration) at a gas rate of 50mL / min, nitrogen as a carrier gas, and keeping at 675°C for 60 minutes. The gas analyzer measures the content of various gases in the tail gas in real time and collects t...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Granularityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a low-temperature phosphogypsum decomposition method belonging to the field of chemical preparation of phosphorus. In the phosphogypsum decomposition and sulfur/calcium resource recycling process, hydrogen sulfide is used as reducing gas, and calcium chloride is added to decrease the phosphogypsum decomposition temperature by 300-350 DEG C to 650-700 DEG C, thereby effectively reducing the energy consumption in phosphogypsum decomposition, and greatly lowering the phosphogypsum decomposition cost, wherein the gas product sulfur dioxide can be used as raw gas for industrial sulfuric acid preparation, and the solid-phase product is mainly calcium sulfide which can be further purified to serve as an industrial raw material. The decomposition method disclosed by the invention is low in cost and has wide market prospects.

Description

technical field [0001] The invention relates to a method for decomposing phosphogypsum at a low temperature, in particular to a method for reducing the decomposition temperature of the phosphogypsum during the decomposition process of the phosphogypsum, and belongs to the resource application field of the phosphogypsum. Background technique [0002] Phosphogypsum is an industrial waste residue produced in the production of wet-process phosphoric acid. For every ton of phosphoric acid produced, nearly 5 tons of phosphogypsum will be produced. Its main component is calcium sulfate dihydrate, and impurities include Si, Mg, Al, Fe and other metals In addition, there are a small amount of undecomposed phosphate rock powder, unwashed phosphoric acid, and traces of radioactive elements. With the rapid development of phosphorus chemical industry, the global annual increase of 280 million tons of phosphogypsum emissions, of which my country's contribution is 50 million tons, accounti...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01F11/00C01B17/50
Inventor 马丽萍谢龙贵戴取秀毛宇张杭
Owner KUNMING UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap