Process for processing coal with low degree of metamorphism

Abstract

The invention provides a technique for processing coal with low metamorphism degree, which comprises the steps of crushing and sieving pretreatment. The technique is as follows: raw coal particles are sent into a drier, and subjected to anoxybiotic hot gas drying under normal pressure, wherein the drying condition is controlled to 10 to 50 cubic meters of hot gas required for each 1 kilogram of the coal, and the temperature of the raw coal particles is controlled to between 210 and 250 DEG C; the raw coal particles are sent into a pyrolysis apparatus, and high-temperature oxygen-poor hot gas is injected according to the flow ratio of 5 to 50 cubic meters per kilogram of coal, wherein the temperature of the oxygen-poor hot gas entering into a pyrolyzing furnace is controlled to between 400 and 950 DEG C, and the oxygen content is controlled to less than 6 percent of the volume; and the coal is fully mixed with the hot gas and heated to a temperature of between 530 and 580 DEG C. The technique has the advantages that the sulfur content is reduced compared with that in the raw coal, so that atmospheric pollution is reduced; solid products produced by the technique have high environment-friendly characteristic; the discharge amount of nitrogen oxide is obviously reduced; and atmospheric pollution is reduced.

Description

technical field [0001] The invention relates to a processing technology of coal with low metamorphism degree, in particular to a technology for obtaining solid products with high calorific value and liquid products with high added value which are easy to transport after drying / upgrading low metamorphism coal. Background technique [0002] Low-metamorphic coal reserves are extremely rich in my country, accounting for about 40% of my country's coal reserves, mainly distributed in Yunnan, Inner Mongolia, Northeast China, Sichuan and other provinces. It is characterized by high water content, generally accounting for 20-60% (received basis); low calorific value, about 2500-4500 kcal / kg; high volatile content, about 40-50% (dry ash-free basis). Coal with low degree of metamorphism is mostly only used as fuel for power plants, but it generally has the problems of difficult combustion and low heat conversion efficiency. Because a considerable part of coal is used to generate enoug...

AI Technical Summary

Problems solved by technology

However, these technologies have the following disadvantages: if most of the moisture in the coal is removed, coal with a low degree of metamorphism is prone to spontaneous combustion, and it is not easy to store for industrial use

[0004] Chinese patent 96108263.1 discloses a method for reducing the water content of low metamorphic coal, but the method is complicated and difficult to control. First, the method needs to be steamed in a sealed pressure chamber sealed to steam, and secondly, the remaining Moisture is mechanically pressed out, and finally the coal with low degree of metamorphism obtained by this method has a large amount of residual moisture

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