Research Progress on Ash-Free Coal Preparation and Application

Due to the ash-free coal with the features of the ash-free, water-free, high thermal activity, good thermal plasticity, high flowability and others, the paper i ntroduced the present research and application status of the ash-free coal to the coal gasification, liquefaction and coking and analyzed the production technique and in fluence factors of the ash-free coal prepared with solvent extraction method.The results showed that the coal extraction rate and the ash-free coal performances obtain ed would be closely related to the raw coal properties and to the technique conditions.With the coal rank reduced, the light component content of the ash-free ash obtai ned would be increased.The coal extraction rate could be increased with the suitable selected solvent, the increased extraction temperature, the acid pre-treatment bef ore the thermal extraction and other method.