How to choose the binders used in coal briquetting?

We all know that charcoal is a material without plasticity, and charcoal powder cannot hold into shape without adding some binders used in coal briquetting. Therefore, it is very important to choose a binders used in coal briquetting, when making charcoal briquettes.

Please take into consideration two factors to choose the proper binding materials, one is binding performance, the other is price. It has been proven that the best binding material for charcoal briquettes is starch, as starch is 100% natural and harmless. Any starch will do but preferably from cassava (tapioca). Cassava starch is the best binding material for charcoal briquettes, because cassava tubers are very cheap in most countries like South America, Asia, Arica, etc. The tubers are as good as starch due to high starch content, which has good performance to tightly bind charcoal fines to charcoal briquettes. Corn starch (maize starch), wheat starch and potato starch can also be used as binders used in coal briquetting which have good binding performance.

When using the starch as binders used in coal briquetting, it is very important to gelatinize the starch. Otherwise, the starch will be useless. Starch gelatinization is just breaking down the intermolecular bonds of starch molecules in hot water, to form a thick paste that will stick the charcoal powder together.

How to gelatinize the starch?

This is a very important processing step. If add hot water to charcoal powder and starch, the binding performance of starch is not the best. If heat starch in water, fully break down the intermolecular bonds of starch molecules, this is correct. But, after starch gelatinization, it will be a problem to mix charcoal fines with gelatinized starch, as it is hard to mix charcoal fines with gelatinized starch evenly. Therefore, our company designed a new spiral mixer to solve that problem, we call it heavy forcing mixer. E.P spiral mixer consists of two parts, one part is for mixing, the other part is for gelatinization. Add charcoal fines, starch, water into the spiral mixer, the mixtures with the best plasticity can be produced.

Other binding materials, such as acacia gum, molasses, cement, clay and tar can be also used, but the resulting briquettes will not be the best.