Production process for high-strength high-volume phosphogypsum baking-free brick

Abstract

The invention relates to a production process for a high-strength high-volume phosphogypsum baking-free brick. The production process comprises the following steps: (1), material pre-treating: mixing phosphogypsum with quick lime to obtain a material mixture, placing the material mixture in drying machinery for drying at 180 DEG C under a normal pressure condition after aging for one day to obtain a dehydrated phosphogypsum-quick lime neutralized material; (2), preparing materials: weighing the dehydrated phosphogypsum-quick lime neutralized material and yellow sand according to a proportion, adding into a stirrer for stirring and uniformly mixing to obtain mixed batch which comprises the following components in percent by weight: 70%-90% of dehydrated phosphogypsum-quick lime neutralized material, and 10%-30% of yellow sand; (3), watering and stirring; (4), pressing and forming; (5), soaking in water and hydrating; and (6), drying. The method provided by the invention is simple in step, not mixed with cement, and low in cost; and moreover, the prepared phosphogypsum baking-free brick is high in strength and suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a production process of high-strength and high-dosage phosphogypsum unburned 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 4.5-5.5t 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, it is weakly acidic and has strong viscosity. Impurities such as fluoride, free phosphoric acid, and phosphate contained in phosphogypsum are the main factors leading to environmental pollution. [0003] The use of phosphogypsum in the production of building wall bricks is an effective way to consume a large amount...

AI Technical Summary

Problems solved by technology

The main disadvantages of this process are: (1) high energy consumption: this process usually requires continuous roasting at a high temperature of 700-900 °C for not less than 30 hours, and this process requires a large amount of heat energy consumption; (2) there is secondary pollution: at high temperature During the roasting process, calcium sulfate dihydrate, the main component of phosphogypsum, will decompose and release sulfur oxides, which will cause secondary pollution to the atmosphere

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

The Chinese invention patent CN102172968B applied by the inventor has designed a hydration recrystallization process, which can prepare phosphogypsum unburned bricks with a compressive strength higher than 20MPa, but there are still some obstacles in the application of the process. Add cement (3-10%) as auxiliary

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