Load-bearing aerated concrete prepared from coal gangue and lime nitrogen hydrolysis waste and its preparation method

Abstract

The invention discloses load-bearing aerated concrete prepared by means of coal gangue and lime nitrogen hydrolysis waste. The load-bearing aerated concrete comprises, by weight, 59-68% of coal gangue slags, 12-17% of coal slags, 5.4-6% of cement, 18.5-23.9% of quicklime, 3.1-3.6% of gypsum, 1.8-2.6% of dilute sulphuric acid and 0.022-0.031% of aluminum powder; in the finished product, MgO accounts for less than 1 percent, and K2O and Na2O account for less than 1 percent; the quicklime is from residues in a cyanamide calcium hydrogen decalcification technology, a large amount of calcium carbonate can be generated in decalcification of cyanamide calcium hydrogen, and the dilute sulphuric acid is partially from sulfur dioxide waste gas which is generated after the coal gangue and coal are burnt. The invention further provides a method for preparing the load-bearing aerated concrete by means of the coal gangue and the lime nitrogen hydrolysis waste. The coal gangue serves as main silica raw materials, and meanwhile the coal is mixed with the coal gangue, so that the coal gangue can be fully burnt to decrease the carbon content and sulphur content as much as possible; residues generated in preparation of dicyandiamide by means of the lime nitrogen serve as the main calcareous raw materials, therefore, the problem of residue discharge in the dicyandiamide technology is solved, the usage amount of the cement is decreased, the heat of coal gangue and coal burning is utilized, and by-product CO2 can be supplied back to the technology for preparing the dicyandiamide by means of the lime nitrogen.

Description

[0001] Technical field: [0002] The invention relates to the technical field of aerated concrete, in particular to a load-bearing aerated concrete prepared by using coal gangue and lime nitrogen hydrolysis waste and a preparation method thereof. [0003] Background technique: [0004] Air-entrained concrete is made of siliceous materials (sand, fly ash and silicon-containing tailings, etc.) , pouring, pre-curing, cutting, autoclaving, curing and other processes made of lightweight porous silicate products. Because it contains a large number of uniform and fine pores after being aerated, it is named aerated concrete. [0005] In a broad sense, air-entrained concrete refers to all air-entrained concrete, including air-entrained concrete blocks, foam concrete and concrete with air-entraining agents. The air-entrained concrete referred to in this article is an air-entrained concrete block. [0006] Air-entrained concrete is a new type of wall building material. It is unique in ...

AI Technical Summary

Problems solved by technology

[0015] A large amount of Ca(OH) will be produced in the process of preparing dicyandiamide from lime nitrogen 2 , CaCO 3 Waste residue and Ca(OH) 2 and NH 3 solution, in the past Ca(OH) 2 , CaCO 3 Waste residue is directly discharged as waste residue, which not only occupies land but also causes land salinization and affects groundwater