Fuel for firing into rotary kiln cement clinker

Abstract

A fuel which is used for rotary kiln cement clinker firing is composed of raw materials with the following weight percentage: coal 3-80, straw substances 0-90, forest products wastes 0-95 and food industry by-product residues 0-70. The straw substances refer to rice straws, wheat straws, cotton stalks, sesame stalks, soybean straws, corn stalks, sorghum stalks, rice husks, peanut shells, soybean shells and corn sticks, the forest products wastes refer to defective bamboo, wood, tree branches, leaves, shrubs, faggot straws and sawdust and wood wool corner scrap materials in the bamboo and wood-processing industry, the food industry by-product residues refer to bran, wheat skin, squeezing meal cake, bean dregs and wine lees, and the coal refers to bituminite, anthracite and coke coal powder. The flue raw materials which are used for the rotary kiln cement clinker firing have wide selecting range, simple preparation, convenient use and rapid burning speed and are beneficial for protecting atmosphere circumstances.

Description

technical field [0001] The invention belongs to the fuel used in the cement industry, in particular to the fuel used for burning cement clinker in a rotary kiln. Background technique [0002] In terms of fuels used in the firing of cement clinker in rotary kilns, high-volatility (≥25%), low-ash (≤20.0%) high-quality smoke heavy metals or heavy oils have long been used as fuels. However, with the global With the increasingly tight energy supply, the traditional way of burning cement clinker with high-quality bituminous coal or heavy oil has seriously restricted the social and economic benefits and development speed of cement enterprises. In this regard, domestic and foreign scientific research institutions and professionals have done a lot of work. Although they have obtained numerous scientific research results and patented technologies, their main technologies and methods are summarized as follows: It is made in a very fine way to increase the burning speed of low-volatili...

AI Technical Summary

Problems solved by technology

However, there are still many defects in this type of method. First, because the coal contains other substances such as sulfur, and the content of low-quality smoke and anthracite with low activity is higher, the harmful waste gas such as sulfur dioxide produced in the combustion process after replacing high-quality bituminous coal is greater, which is bound to It brings more serious damage to the atmospheric environment; second, with the introduction of high ash content, there are more negative impact factors on the firing quality of cement clinker, especially for the firing quality of special cement clinker. The other negative effects of the ash brought in are far greater than the positive benefits, and even lead to the waste of cement clinker; third, the current commercially available coal-burning combustion aids are generally high in price, large in dosage, poor in selectivity to coal types, and seriously Na that affects the clinker firing conditions of the rotary kiln and the final product quality of cement + 、K + , Cl - , Mg 2+ High content of harmful elements such as

The second type is to use urban domestic garbage, waste rubber, and waste plastics to replace part of the coal as the fuel for the cement clinker of the rotary kiln. The kiln production process equipment undergoes special transformation and the investment is large, and the actual replacement amount is small. At the same time, the harmful components in the exhaust gas emitted during the production process increase, and the heavy metals contained in the burnt ash cannot be completely solidified in the clinker minerals. , free heavy metals will still cause secondary pollution to the environment