A new approach for processing and agglomeration of low-rank coals for material usage

Abstract

The material usage of low-rank coal offers a high potential regarding the increasing in added value. The production of coke from a wide span of low-rank coals may be a promising perspective. Since low-rank coals do not exhibit any baking properties they need to be briquetted before pyrolysis to get a lump coke. Using two brown coals the influence of processing parameters and briquetting parameters were investigated. The comprehensive investigations showed that, besides the well-known relations between briquetting parameters, the changing of processing from conventional comminution of the coal to new processing leads to increasing strength of briquettes and coke. Due to the intense novel comminution in the flat die press as well as in the mixer the binding between the particles may be increased and the shrinkage behaviour of the coals was improved during pyrolysis so that coke strength could even exceed the briquette strength. The new developed pyrolysis briquettes and the lump coke show high mechanical strength and only small amounts of fines due to the mechanical stress, leading to high yield in the coarse coke fraction.