Lime kiln lime burning is an important part of industrial production, and the coal used in this process has a direct impact on the quality and production efficiency of lime. This article will ** What are the requirements for calcined lime charcoal, and why we need to choose a high-quality coal source for calcination.
1. The process of burning lime in lime kilns and the influence of coal.
Lime kiln lime burning is a complex chemical reaction process that decomposes limestone (CaCO3) into quicklime (CaO) through high-temperature calcination. In this process, the coal used is used as fuel to provide the required heat for the calcination process. The influence of different qualities of coal on the calcination process is significant. Generally speaking, high-quality coal has a higher calorific value, which can provide a more stable heat input during the calcination process, thus ensuring a more complete and uniform decomposition reaction of limestone. Conversely, coal with low calorific value may produce unstable heat input during combustion, resulting in uneven decomposition of limestone and affecting lime quality.
2. Requirements for coal: more than 6,000 kcal.
When selecting coal for lime kiln to burn lime, it is generally required that its calorific value is more than 6000 kcal. This calorific value requirement is to ensure that the coal can provide enough heat during combustion to achieve complete decomposition of the limestone. Calorific value refers to the amount of heat released per unit mass or volume of fuel when it is fully combusted. The higher the calorific value, the higher the heat generating capacity of the fuel. In the calcining of lime, the use of coal with a higher calorific value can reduce fuel consumption and increase production efficiency.
3. Disadvantages of low calorific value coal.
Calcination with coal with low calorific value poses a number of problems. First of all, the combustion process of low calorific value coal may be unstable, resulting in uneven heat input and affecting the decomposition reaction of limestone. Secondly, in order to achieve the same heat input, more fuel needs to be consumed, which increases the cost of production. In addition, low calorific value coal can also lead to incomplete combustion, produce a large amount of exhaust gas and solid waste, and cause pollution to the environment.
Fourth, how to choose the right coal.
Understand the ** of coal: When choosing coal for calcination, you should try to know its origin, formation process and mining method. Generally speaking, high-quality coal comes from mining areas with a long geological age and good coal-forming conditions, such as some large-scale coal mines in China. Knowing this information can help assess the quality and calorific value stability of coal. Detection of the calorific value of coal: After the coal has been selected, a calorific value test should be performed to confirm that the calcination requirements are met. There are many methods for calorific value detection, such as cartridge method, calorimetry method, etc. Through testing, more accurate calorific value data can be obtained, so as to determine whether the coal is suitable for calcination. Consider other indicators: In addition to the calorific value, other indicators of coal, such as ash, volatile matter, and sulfur content, need to be considered. Ash refers to the content of inorganic substances in coal, and too high ash content will affect the quality and yield of lime. Volatile matter refers to the content of flammable gases in coal, and too high volatile matter may lead to unstable combustion. Sulphur content refers to the amount of sulfur in coal, and too high sulphur content will not only increase fuel consumption but also cause pollution to the environment. Therefore, the selection of the right coal needs to consider the combined influence of several factors to ensure the proper operation of the lime kiln and the production of high-quality lime.