Process for treating, stabilising, rendering inert, detoxifying, landfilling and disposal of mineral wastes, scrap materials and residues and for recovering metals and producing soil substrates

摘要

A process appropriate to the requirements of an up to date recycling industry is presented which permits the treatment of wastes, residues and polluted materials, if their toxicity is due to the presence of excessive heavy metal content, independently of the form and physical state, for example flue gases, dusts, waste waters, landfill waters, circulated water, sludges, filter ashes, filter dusts and slags with the result that they are substantially freed of heavy metals. The process is essentially based on sulphide washing and sulphide precipitation, preferably using dissolved calcium sulphide. For the extraction from solid materials such as filter ashes as special waste or sludges, neutralisation and extraction with waste acid, in particular dilute acid, is provided which is simultaneously disposed of in the course of the process. The acidic extracts, in accordance with the process requirements, must be neutralised with waste alkalis, basic landfill waters, for example from brown coal ash landfills and other basic liquids until the pH desired for the sulphide precipitation is achieved. The basic waters are simultaneously freed of heavy metals in the course of this. The materials freed of heavy metal can either be deposited in a less costly manner in less expensive landfill classes or can be used for environmentally appropriate production of soil substrates for example in the recultivation sector. The [lacuna] by sulphide scrubbing from flue gases or sulphide precipitation from ... Original abstract incomplete.