Method for comprehensive utilization of red mud, phosphogypsum and coal gangue

Abstract

A method for comprehensive utilization of red mud, phosphogypsum and coal gangue comprises the following steps: red mud, phosphogypsum and coal gangue are used as main original burning materials, a correction material is taken as a secondary original burning material, a homogeneous moisture material is prepared through two-stage batching process and is shaped or dried and crushed, and then a clinker product including main ingredients of dicalcium silicate, calcium sulphoaluminate and calcium sulphoferrite is prepared through calcination. The clinker produced by the method can be not only directly sold as a product but also further processed into a cementing material or product for sale by utilizing the prior art. The method provided by the invention is simple in process and low in investment, the production scale can be either big or small, a rapid hardening early strength clinker produced by the method is wide in use and relatively higher in value, not only are lots of clay resources and non-renewable burning coal saved, but also environmental pollution caused by waste pollutants are effectively reduced, secondary disasters is prevented, and high industrial competitiveness and favorable investment economical efficiency are realized.

Description

technical field [0001] The invention relates to the comprehensive utilization of industrial waste, in particular to a method for comprehensively utilizing red mud, phosphogypsum and coal gangue to produce cementitious materials and products. Background technique [0002] Red mud is a very fine-grained strong alkaline solid waste produced during the process of extracting alumina from bauxite. For every ton of alumina produced, about 0.8 to 2 tons of red mud are produced. The red mud produced according to different extraction processes is called Bayer red mud, sintering red mud and combined red mud. Physical properties of red mud: particle diameter 0.088-0.25mm, specific gravity 2.7-2.9, bulk density 0.8-1, melting point 1200-1250°C. The mineral composition of red mud is complex, the main minerals are aragonite and calcite, the content is 60-65%, followed by opal, gibbsite, goethite, and the smaller content is titanium ore, siderite, trona, water glass , sodium aluminate and...

AI Technical Summary

Problems solved by technology

[0009] 3. After the red mud is dried, add cement, lime, etc. to grind to produce mine cemented filling cementitious materials; in addition to stockpiling dry and hardened red mud, red mud drying consumes a lot of energy, and the produced mine cemented filled cementitious materials The solidification and stabilization effect of the alkali and harmful metal ions in the solution is extremely poor, and actually still pollutes the groundwater

[0012] 6. Chemically combine ceramic composite materials, use red mud dry powder after removing impurities, drying, and grinding to replace part of the porcelain mud materials, and prepare ceramic composite materials. The energy consumption of removing impurities, drying, and grinding is high. The characteristics and fluctuations of the chemical composition of mud make it difficult to control the color, strength and yield of ceramics, resulting in a substantial increase in the cost of qualified products

[0013] 7. Insulation and refractory materials: replace part of the refractory mortar with the red mud after removal of impurities, drying and grinding to fire refractory materials, or use red mud powder, refractory lightweight aggregate and refractory mortar that have been treated with removal of impurities, drying and grinding Add foaming agent to roast to produce thermal insulation refractory material, because the melting point of red mud itself is relatively low, and the energy consumption of removing impurities, drying and grinding is relatively high, but no substantial breakthrough has been made

Coal gangue in coal mining enterprises has already piled up like a mountain, causing secondary disasters continuously, and even the government subsidy of 100 yuan / ton is difficult to effectively deal with