Novel technology of vertical kiln for manufacturing cement clinker by utilizing dry acetylene sludge two-stage batching

Abstract

The invention discloses a novel technology of a vertical kiln for manufacturing cement clinker by utilizing dry acetylene sludge two-stage batching, which comprises the steps of utilizing dry acetylene sludge to substitute limestone in cement raw meal batching fully or partially, taking the dry acetylene sludge as the main material of the cement raw meal to be subjected to second-stage batching directly with other materials after first-stage batching grinding, mixing evenly, manufacturing a raw meal rod or a raw meal ball, entering the vertical kiln and forming the cement clinker by calcining. The invention has less investment and low energy consumption, takes effect rapidly, is easy for achieving environment protection standard, saves resources of coal, electricity and limestone and reduces CO2 discharge, thus being a novel energy-saving, consumption-reducing and environment-protecting technology.

Description

technical field [0001] The invention relates to a building material, in particular to a new process for producing cement clinker in a shaft kiln using dry-process acetylene carbide slag batching, which is a kind of chlor-alkali industrial waste residue treatment and cement industry in comprehensive utilization of resources, energy saving and environmental protection. new technology Background technique [0002] Carbide slag is the industrial waste residue of PVC, PVA and other resins produced by the acetylene method in the coal chemical industry. In the past, the wet acetylene process was used, and the water content of the carbide slag slurry reached more than 90%. With the progress of the country and the requirements of water saving and energy saving, the dry process acetylene water saving process has been popularized and applied. The dry process acetylene carbide slag is mostly powdery with a water content of 4-10%. The large-scale utilization of carbide slag is to produc...

AI Technical Summary

Problems solved by technology

[0003] The dry acetylene carbide slag is used to produce cement by the new dry method rotary kiln process. After the calcium carbide slag is mixed with other raw materials, a vertical mill with strong drying capacity is used to dry and grind the raw material. The moisture content of the feed powder is required to be less than 1.5%, and the heat consumption of clinker firing can be reduced to 3100-3360kJ / kg; however, the biggest problem with the use of calcium carbide slag in the new dry rotary kiln process is that it is difficult to ensure continuous production, and calcium carbide must be controlled during production. The amount of slag should be below 15%, that is, the moisture content in the flue gas should not exceed a certain limit to ensure the normal and continuous operation of production

This is due to the Ca(OH) in carbide slag 2 The decomposition temperature is around 580°C, the Ca(OH) in carbide slag 2 with CaCO in limestone 3 The decomposition products are water and CO 2 The difference is large, and the high temperature cyclone and calciner cone are prone to clogging, resulting in continuous and stable production.

The effective solution is to carbonize calcium carbide slag to more than 85% or pre-roast and decompose it into quicklime, but it is very uneconomical

On the other hand, some acetylene processes use waste sodium hypochlorite solution, so the alkali content and chlorine content in the calcium carbide slag are too high, which will lead to serious crusting, nodules and blockage, and the new dry method rotary kiln is difficult to operate normally

[0004] According to relevant domestic and foreign literature, the most advanced cement clinker production process with carbide slag is a new dry method rotary kiln production process. Although the heat consumption of clinker firing is low, it is difficult to ensure continuous and stable production when the amount of carbide slag is more than 15%. operation, there is no economical solution at present, coupled with excessive investment, it is difficult to popularize and implement

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