HiBar Steam Pressure Filtration of Coal Ultrafines - New Developments and Results

Abstract

HiBar Filtration is the most modern technology of continuous pressure filtration also known as hyperbaric filtration. HiBar Filtration enables low moisture contents, high specific solids performance and efficient filter cake wash if fine grained, difficult to filter products have to be processed. Lowest cake moisture contents are achieved with HiBar Steam Pressure Filtration. With this hybrid separation process the filter cake is treated with steam immediately after emerging from the slurry. In a specially designed and patented steam hood the filter cake is only partially exposed to steam, which accelerates and intensifies the dewatering process. For many products the dryness of the filter cakes significantly improves quality, handling and transport of the product. At filtration of bulk materials such as coal ultrafines these are decisive criteria. HiBar steam pressure filtration is capable to produce extremely dry ultrafines below 10 % w/w free moisture which now offers new options in coal ultrafines treatment. In July 2014 the BOKELA HiBar pilot plant was operated at the coal washery Auguste Victoria (RAG), Germany, for Steam Pressure Filtration of coal ultrafines in front of experts from the international coal industry. It was a world premiere and for the first time filter cakes of dry coal ultrafines below 9 % w/w free moisture were produced in a semi-industrial scale.