Method for processing non-autoclaved foam concrete building blocks in producing phosphogypsum through microwave high temperature

Abstract

The invention discloses a method for processing non-autoclaved foam concrete building blocks in producing phosphogypsum through microwave high temperature, which comprises the steps as follows: solid waste phosphogypsum in the phosphate fertilizer industry is arranged in a microwave tunnel furnace and is heated to 200-770 DEG C for 3-5min to lead a plurality of impurities in the phosphogypsum like phosphoric acid, calcium fluoride, iron aluminum oxide, acid-insoluble matters, organic matters and the like to volatilize or convert into inert materials during the heating process, thereby obtaining beta-type semihydrated gypsum or beta II-type anhydrous gypsum; then the beta-type semihydrated gypsum or beta II-type anhydrous gypsum, fly ashes, cements, quicklime and modified additive are mixed and levigated, then are stirred with water and gypsum waterproofing agent, and finally are uniformly mixed with foams of foaming agent and poured into a building brick die. The method disclosed by the invention has the following advantages: the method has simple technique, low equipment investment and lower manufacture cost and avoids secondary pollution; the microwave high temperature method has quick processing speed and uniform quality; the utilization amount of phosphogypsum waste residues is large and the utilization rate is as high as 60-70 percent; moreover, the building blocks belong to obturator structures and has good insulating effect, high strength and good waterproof performance.

Description

technical field [0001] The invention relates to the technical field of phosphorus chemical industry or building materials, in particular to a method for producing autoclaved-free foam concrete blocks by treating phosphogypsum with a microwave high-temperature method. Background technique [0002] Phosphogypsum is a solid waste from the phosphate fertilizer industry. According to incomplete statistics, the piled phosphogypsum slag in my country has reached 160 million tons at present, and will increase at a rate of more than 20 million tons per year. Because the utilization rate is less than 10%, it not only pollutes the environment, occupies land, but also affects sustainable development. The traditional treatment methods for phosphogypsum mainly include: ①Washing method. It takes 4 tons of water to process 1 ton of phosphogypsum, which not only wastes precious water resources, but also causes secondary pollution. ② Calcination method. It consumes energy coal, pollutes t...

AI Technical Summary

Problems solved by technology

The problems caused by the production of aerated blocks from unmodified or incompletely modified phosphogypsum are: low utilization rate of phosphogypsum, low compressive strength, high investment cost and production cost of autoclave equipment, etc.

For example, the Chinese invention application with the application number 200910094937.9 "A method for producing aerated blocks using phosphogypsum" has the following deficiencies: first, the production cost of steam curing is high; second, the compressive strength of the product is low, only 2.7Mpa; It uses aluminum powder to generate gas, and the block has an open-pore structure, which has poor thermal insulation effect and high water absorption rate.

Another example is the Chinese invention application "A kind of phosphorus slag autoclaved aerated concrete block and its preparation method" whose application number is 200910304521.5. Autoclave equipment investment is too large, the production cost is high; the third is to use aluminum powder to generate gas, and the block has an open-pore structure, which has poor thermal insulation effect and high water absorption rate.