Method for decomposition treatment and resource utilization of ardealite by using sintering machine

Abstract

The invention discloses a method for decomposition treatment and resource utilization of ardealite by using a sintering machine. The method comprises the steps of granule preparation, feeding and longitudinal roasting. The ardealite, coal or coal gangue and binders are mixed, granulated, dried and put into the sintering machine in a layered mode, the temperature of a material layer of the sintering machine and the sintering retention time are controlled, air is induced to achieve longitudinal thermal decomposition of particles, and obtained SO2-containing flue gas can be used for wet-process phosphoric acid production; and roasting residues containing calcium oxide and the like can be used as building raw materials. According to the method, granulation roasting is taken as a core, and a particle layered distribution structure and longitudinal roasting of the sintering machine are utilized, so that the heat storage effect can be enhanced, the pressure drop loss is reduced, the full decomposition of phosphogypsum is realized, the phosphogypsum decomposition efficiency is high, and the dust concentration, the dust removal load, the fluidization power consumption and the equipment wear can be effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of phosphorus chemical industry, and specifically relates to a method for decomposing and disposing phosphogypsum by using a sintering machine and utilizing it as a resource. Background technique [0002] my country is a country that uses coal as the main energy source. my country's coal resources have a large amount of coal resources, but the per capita recoverable reserves are small, and high-sulfur coal accounts for a large proportion of them. Since the sulfur content in high-sulfur coal is greater than 3%, the combustion will emit a large amount of SO 2 As the main pollutant, it causes serious pollution to the environment, so its mining and sales are restricted. In addition, a kind of solid waste called coal gangue will be produced during the coal mining and cleaning process, accounting for about 15% of coal production. Since there is no way to find a large-scale utilization...

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Problems solved by technology

[0004] In the current research on the resource utilization of phosphogypsum, the decomposition of phosphogypsum to produce SO 2 Recycling Ca and S resources with CaO is one of the current main concerns, but in research and production examples, hollow rotary kilns and circulating fluidized bed boilers are often used as pyrolysis furnaces to process and decompose phosphogypsum. problems such as low sulfur content and difficulty in sulfur recovery; at the same time, the roasting process of rotary kiln and fluidized bed boiler is easy to form rings, easy to burn, large equipment wear, and high energy consumption. However, it cannot meet the needs of industrial production, which limits its large-scale promotion and use.

[0005] Chinese patent CN112250051A discloses a method for phosphate rock slurry to absorb phosphogypsum roasting flue gas and co-produce phosphoric acid and cement clinker. The method is to put the homogenized material into the hollow long kiln for pyrolysis. Roasting leads to high dust concentration and large dust removal load. At the same time, due to the abrasion of materials, dust and equipment at high temperature, there are problems such as large equipment loss and poor operation continuity.

[0006] Chinese patent CN101602518A discloses a production process for preparing calcium oxide and sulfur dioxide by decomposing phosphogypsum. The process is to put the granular material mixed and granulated with phosphogypsum into a fluidized bed decomposition furnace, and then feed coal gas or natural gas to generate high temperature. The furnace gas reacts directly with the granular material, and there are problems such as expensive coal gas and natural gas, and poor technical and economic efficiency.

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