Types of mineral coals:
There are four main types of mineral coal
The range refers to a natural and slow process that lasts approximately 300 million years, "carbonification" occurs, during which the fossilized plant matter goes through bacterial processes, it is transformed into a material that is increasingly dense, drier, rich in carbon. and harder.
The four ranges that occur are:
The highest range of coal. It is a very hard and lustrous coal, also called "coal", which contains a high percentage of fixed carbon and a low percentage of volatile matter. In water treatment it is only used as a filter medium for suspended solids. Due to its hardness and characteristics, it is very difficult to activate, to produce activated carbon.
Bituminous coal is a medium-range coal between subbituminous and anthracite. Bituminous usually has a high calorific value (Btu), it is the type of coal most commonly used in the generation of electricity and water treatment as an adsorbent for organic matter in surface waters. Bituminous coal appears shiny and smooth when viewed with the naked eye, but if you look closer, you can see that it has more opaque layers.
Subbituminous carbon is black and opaque (not shiny), in water treatment applications it can sometimes replace lignitic. It has a higher calorific value than lignite.
Lignite or Lignitic:
Lignite or lignite coal is the lowest grade coal with the lowest concentration of coal. So it makes it the softest of all, when activated it produces very large pores, which can be used to adsorb color molecules.
There is also the peat. Peat is not actually coal, but rather the precursor to coal. Peat is a soft organic material of partially decomposed plants and, in some cases, in matter with some mineral deposits. When peat is subjected to high pressure and heat, it turns into charcoal.