PROCESS FOR THE MICROBIOLOGICAL PURIFICATION OF SLURRIES CONTAINING HEAVY METALS

摘要

The invention relates to a process for the microbiological purification of slurries containing heavy metals, whereby a slurry containing heavy metals and oxidizable sulphur compounds is percolated with an acidic process water and the heavy metals released through microbial activities are separated from the process water using standard methods, characterised in that so much sulphur is added to the slurry in the fixed bed reactor before and/or during the microbial leaching with the process water that a total content of oxidizable sulphur compounds, related to the dry product, is achieved of at least 2 % and at most 4 %, and in that the process water is set to a pH value < 4 with sulphuric acid at the beginning of the microbial leaching.