Pfeiffer products for coal and petcoke preparation
Special knowledge is required when grinding fuels used in a great many industries
Coals and similar materials are combustible and may also be explosive depending on the amount of volatiles they contain. Thanks to our experience gained by the supply of more than 2200 coal mills to the most different industrial sectors, we know everything about safety issues: when is inert operation imperative, when is it dispensable provided specific safety concepts are provided, and how do these safety concepts have to be integrated into the grinding process? With petcoke and sponge coke, but particularly with the sphere-shaped petcoke, quite a different challenge needs to be met: despite the fineness of these feed materials, mill operation must be stable and smooth. And this is ensured by the geometry of the grinding elements of our coal mills which is particularly advantageous in this respect.
Details on raw material
Hard coal is a sedimentary rock which was formed by deposition and carbonization of plant remains. It is hard and resistant. More than 50% of its weight is made up by carbon. Therefore it is classified as high-rank coal. Other fossil fuels like sub-bituminous coals with high moisture contents as well as brown coal and lignite are lower ranked. Lignite, which is the lowest ranking fossil fuel, is defined between peat and hard coal.
Petcoke is not a natural product. It is a byproduct derived from the oil refining process. Mainly consisting of carbon, it is above all used as fuel. The production of petcoke is similar to that of coke produced from coal.
Our machines and products for the coal industry
Coal grinding using available process gases
Coal, lignite or petcoke are ground in the Pfeiffer vertical mill by using available hot process gases. The grinding plant can be inerted. The raw coal is dried while being ground in the mill even if feed moisture exceeds 25%. The feed size that can be handled is up to 100 mm, making two-step pre-crushing unnecessary.
Coal grinding without process gases
Coal, lignite or petcoke are ground in the Pfeiffer vertical mill by using hot gases from a hot gas generator. The grinding plant can be inerted. The raw coal is dried while being ground in the mill even if feed moisture exceeds 25%. The feed size that can be handled is up to 100 mm, making two-step pre-crushing unnecessary.