Process for producing high content phosphor-gypsum baking-free bricks

Abstract

The invention relates to a process for producing high content phosphor-gypsum baking-free bricks. The process for producing the high content phosphor-gypsum baking-free bricks is characterized by comprising the following steps of: (1) proportioning: selecting the following raw materials in percentage by mass: 80.0 to 90.0 percent of phosphor-gypsum, 2.0 to 3.0 percent of lime, 0.0 to 15.0 percent of yellow sand, 3.0 to 10.0 percent of cement, and water in an amount which is 3 to 8 percent of that of the proportioned raw materials; (2) stirring and mixing; (3) pressing and molding; (4) wet curing; (5) drying and dehydrating: transferring the air-dried brick blanks to a dryer, and performing drying and dehydrating treatment for 2 to 6 hours at the temperature of between 125 and 180 DEG C under normal pressure to obtain dehydrated brick blanks; (6) hydrating and re-crystallizing: naturally cooling the dehydrated brick blanks to room temperature, soaking the brick blanks into room temperature water for 0.5 to 2 hours till the brick blanks are totally soaked, and obtaining hydrated and re-crystallized brick blanks; and (7) performing natural curing and drying to obtain the phosphor-gypsum baking-free bricks. The process has the characteristics of high phosphor-gypsum content, low production energy consumption, high product strength, simple production process and strong operability.

Description

technical field [0001] The invention belongs to the technical field of building wall materials, and in particular relates to a production process of phosphogypsum unfired bricks. Background technique [0002] Phosphogypsum is an industrial solid waste discharged from the wet-process phosphoric acid production process. In the production process of wet-process phosphoric acid, usually every 1t of phosphoric acid produced (with 100% P 2 o 5 Calculation) produces about 4.5t~5.5t of phosphogypsum. The main component of phosphogypsum is calcium sulfate dihydrate (CaSO 4 2H 2 O), in addition to containing a small amount of other impurities, acidic, high water content, strong viscosity. Impurities such as fluoride, free phosphoric acid, and phosphate contained in phosphogypsum are the main factors leading to environmental pollution. At present, the disposal of phosphogypsum in my country usually adopts the traditional storage method, which not only encroaches on land resources...

AI Technical Summary

Problems solved by technology

The main deficiency of this technique is: (1) energy consumption is high

The main disadvantages of this process are: (1) higher energy consumption

The main disadvantages of this process are: (1) low product strength

The compressive strength of unfired bricks in this process is usually lower than 10MPa, and the range of use of the product is greatly limited; (2) The molding pressure is high, the equipment requirements are high, and the power consumption is large

This process requires high-pressure molding, and the molding pressure is generally greater than 40MPa, or even as high as 80MPa. Therefore, the requirements for the material and structure of the pressing molding equipment are relatively high, and the power consumption is also relatively large.

[0008] In addition, in the existing production process of phosphogypsum to manufacture building wall bricks, the content of phosphogypsum is generally low, generally lower than 60%, as shown in Chinese patent publication numbers CN101182179A, CN101397205A, CN101637936A, CN1673154A, CN101508556A and other patents

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