Coal briquette machine can be used to press all powdery materials into briquettes such as coal powder and iron powder. There are many factors affecting the quality of coal briquettes like different briquetting methods, the nature of raw coal, the type of binder and the particle size of coal.
1. Different briquetting methods
The mechanical strength of coal briquettes largely depends on different briquetting methods. In general, coal briquettes produced by thermal dynamic process have the best (cold/hot state) strength, then followed by lime carbonized briquettes and clay briquettes, and wet coal briquettes have the worst strength.
2. The nature of raw coal
The nature of raw coal such as coalification, adhesiveness and moisture is a very important factor affecting the strength of coal briquettes.
When use binder-free shaping at high pressure, you should choose young lignite which has low degree of coalification and is loose in structure or anthracite going through weathering and containing adhesive clay. In a word, raw coal with small hardness and elasticity and good plasticity will produce briquettes with high strength.
Hot briquetting refers to the use of adhesive gelatinous material produced by rapid heating process of bituminous coal to press coal powder into briquettes. However, not all bituminous coal can be hot briquetted. If raw coal is strongly adhesive, it is easy to cause blockage during hot briquetting process. But weakly adhesive raw coal may generate less gelatinous material, so they are not easy to be briquetted. Therefore, the adhesiveness of raw coal is a determining factor for hot briquetting and briquettes strength.
When use hydrophobic binder, in order to ensure a full contact between binder and coal particles, water must be removed as much as possible. When use hydrophilic binder such as lime, humic acid and clay, it has certain requirement for moisture content. Here it refers to the sum of raw coal moisture and binder moisture content. Proper moisture content can play the role of wetting, lubricating and reducing internal friction.
3. The type of binder
Binder will exert different effect on different raw coal, so users should choose appropriate binder. Besides, the amount of binder added is also essential.
4. The particle size of coal
In the coal briquetting process, the smaller particle size promotes the contact among coal particles, which can improve the briquettes strength. But at the same time, it will increase the consumption of binder. It is believed that the particle size less then 3 mm is more appropriate.
If you have more questions about briquetting , please consult us---Zhongzhou coal briquette machinery!