Conventional briquetting of coal fines

Mostly due to environmental reasons and in some cases based on economical considerations, renewed interest in the briquetting of coal fines has become evident in many locations. As general interest in new investments declined, many of the firms that were traditionally engaged in this field went out of (that) business only a few companies are still offering equipment and know-how for the conventional briquetting of coal fines with roller presses. 

In the following the most important considerations will be discussed and a typical, conventional plant for the production of 60-70 t/h of egg-shaped coal briquettes will be described. 

In general, the process line consists of a preparation section where coal is crushed and screened to the desired particle size of --3 mm for briquetting. The fine coal is then transferred to a drying facility where the water content is reduced so that no surface moisture remains. Depending on the coal source, crushing 

Preparation section If crushing is necessary, correct selection of the mill is of the utmost importance. Depending on the coal type, different mills and/or operating conditions of the crushing equipment may be required. It is desirable to produce a feed for briquetting which is not too fine but has a wide particle size distribution and features high bulk weight. Normally, impact mills are applied. 

Drying, if required, is accomplished in flash dryers. Heat is produced by burner systems fired with coal dust. The coal is intensively dried in suspension in the vertical dryer tube and collected in dust-collection systems. 

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