Processes for the treatment of residues from the burning of incense into an environmentally sound and usable product for construction purposes

摘要

In the conversion of mainly inorganic waste incineration products, contaminated with heavy metals and/or heavy metal compounds, and/or analogs to give environmentally acceptable products by means of a fusion-thermal treatment, an iron-containing melt is used whose iron content can be adjusted by addition of iron or of an iron compound. The melt is first fused in a reactor above 1300 DEG C. The melt is then oxidised with vigorous agitation by blowing in an oxygen-containing gas until all the metals and metal compounds present in the reactor have been converted into the oxide form, the melt being held, at least at the end of the oxidation, above 1450 DEG C and preferably at about 1500 DEG C. Subsequently, the melt is reduced, preferably by means of a part fraction of the waste incineration product and/or iron, preferably in the form of scrap, and/or hydrogen. The reduction can then be continued by means of added aluminium and/or calcium and/or ferrosilicon. If appropriate, molten metal is fractionated in a lower part of the reactor, and molten slag is collected separately as a supernatant layer. Heating energy can be saved by heat exchange and recirculation of fluid. IMAGE