A kind of high-strength water-resistant phosphogypsum composite cementitious material and its preparation method

Abstract

The invention relates to a high-strength water-resistant phosphogypsum composite gelling material and a preparation method thereof, which belongs to the field of building materials and provides a high-strength water-resistant phosphogypsum composite gelling material and a preparation method thereof, comprising the following components in parts by weight: phosphorus 100 parts of building gypsum powder, 0.5-4 parts of rheological agent, 3-7 parts of cement, 4-10 parts of sulfur-fixed ash, 3-10 parts of coal gasification slag, 0.5-3 parts of zeolite powder, 1-4 parts of waterproofing agent , 0.2 to 3 parts of calcium oxide. Through the synergistic effect of rheological technology and waterproof modification technology, the present invention significantly improves the rheological properties, mechanical properties and water resistance of β-type phosphogypsum slurry; industrial solid wastes such as sulfur-fixing ash and coal gasification slag are used for phosphorus Improve the water resistance and mechanical properties of gypsum products. The invention can prepare environment-friendly, low-cost, high-strength and water-resistant phosphogypsum composite gelling material: the softening coefficient is 0.9-1.2, the saturated water absorption rate is below 5%, and the compressive / flexural strength is 25-45 / 5-13 MPa, which can be used Widen the application fields of industrial by-product phosphogypsum products in areas prone to moisture such as kitchens, bathrooms, and outdoors.

Description

technical field [0001] The invention relates to a high-strength water-resistant phosphogypsum composite gelling material and a preparation method thereof, belonging to the technical field of building materials. Background technique [0002] Phosphogypsum, an industrial by-product, is a by-product of phosphate fertilizer production by wet method, and its main component is calcium sulfate dihydrate. Due to the huge domestic demand for phosphate fertilizers and phosphorus chemical products, a large amount of industrial by-product phosphogypsum will inevitably be produced in the production process. At present, the stock of phosphogypsum in China exceeds 500 million tons, and the annual output is increasing by 70 million tons, causing huge pollution to the environment. The development of phosphogypsum-based materials is in line with the national green building materials development strategy and the policy of recycling solid waste resources. Gypsum has the advantages of light wei...

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Problems solved by technology

[0003] Common phosphogypsum products on the market, especially those produced with β-type architectural phosphogypsum powder, have problems of poor water resistance and low strength.

The crystal surface of β-type phosphogypsum is rough, contains a certain amount of phosphorus and fluorine impurities, has many cracks, and the compressive strength is only 4-7MPa; and the softening coefficient is low, usually 0.3-0.5; Compared with α-type gypsum, it has the characteristics of large water demand, low strength and poor water resistance, and it is more difficult to prepare high-strength water-resistant gypsum products, which limits the application of β-type phosphogypsum.

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