Cement clinker calcinated on vertical kiln using full calcium carbide slag to instead limestone and its preparation method

Abstract

A cement clinker is proportionally prepared from calcium carbide dregs instead of lime stone, Si-Al correcting material, Fe material, and anthracite through baking, grinding, homogenizing, adding water, sphericizing and calcining in mechanical vertical kiln.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a high-quality cement clinker calcined on a shaft kiln with calcium carbide slag instead of limestone ingredients and a preparation method thereof. Background technique [0002] my country's cement clinker calcination technology has gone through the following stages: [0003] After liberation in 1949, the development of my country's cement industry mainly focused on the development of wet kiln cement calcination technology in the south, and the development of dry rotary kiln production technology in the north. Subsequently, a large number of shaft kiln cement plants were built, taking ordinary shaft kilns and machine shaft kilns as examples. With the development of science and technology and economy, machine shaft kilns have become the main equipment for cement clinker calcination in cement enterprises, and ordinary shaft kilns have been eliminated. . [...

AI Technical Summary

Problems solved by technology

Due to Ca(OH) 2 Because it is rich in calcium oxide, it is a good substitute for limestone raw materials. However, the large amount of calcium carbide slag discharged from such chemical plants has not been fully developed and utilized. In most cases, the method of accumulation can only be used, which occupies land , causing environmental pollution and destruction

[0006] In the past, although some cement companies used industrial waste such as calcium carbide slag to produce cement clinker, most of them were low in dosage (generally 15-60%) and high in energy consumption (heat consumption above 1000KcaC / kg of clinker); Jilin Chemical Plant and Tianjin Chemical Plant were the first to use calcium carbide slag to produce cement clinker. Due to their backward wet process, the water content of the raw material slurry entering the kiln is greater than 65%, the output of the kiln is low, the heat consumption is high, and the benefit is poor. The utilization of calcium carbide slag is not sufficient; in 1989, Jilin Siping Chemical Plant, and in 1992, Jiangsu North Chlor-Alkali Group Co., Ltd. built a shaft kiln cement clinker production line with calcium carbide slag as part of the raw material. It is added as an auxiliary material, so technicians in this industry generally believe that calcium carbide slag can only be partially mixed in order to stabilize the firing process, and cannot be used on a large scale. Difficult, but also difficult to pelletize and calcine, there is no teaching in the prior art that carbide slag can be used to completely replace limestone as the main raw material for cement production, and there is no use of calcium carbide slag to completely replace limestone as cement production in the shaft kiln The teaching of the main raw materials

[0007] Recent studies have shown that the fundamental reason why calcium carbide slag cannot completely replace limestone as the main raw material is that the influence of the components contained in calcium carbide slag on the production of cement has not been fully analyzed. If the amount of calcium carbide slag is too large, the CaO content in the raw meal will be too high, which will greatly increase the water demand for ball formation, reduce the quality of ball formation, and the free calcium oxide (f--CaO) of the fired clinker will be high. It will seriously affect the stability of cement; secondly, the water content of calcium carbide slag is also an important reason. If the water content is too high, if the dry method is used to make the ingredients into balls, it will increase energy consumption and production costs.