Method for treating sludge containing free lime generated by wet processing of slag generated from steelworks

摘要

PROBLEM TO BE SOLVED: To effectively utilize sludge of flied ash containing free lime for aggregates for civil engineering works, etc., by adding fly ash to the sludge containing the free lime to remove water, curing and solidifying the obtained dehydrated cake and then grinding the solidified product. SOLUTION: This method for treating sludge comprises (1) the step of adding fly ash to the sludge containing free lime to hydrate the sludge, (2) the step of curing and solidifying the dehydrated cake produced in the dehydration step; and (3) the step of grinding the dehydrated cake treated in the curing step into a ballast-like product. This treatment method enables to produce coarse aggregates or fine aggregates from the sludge containing the free lime produced from steel production slag generated from a steel mill, and to utilize the fly ash generated from steel mills, coal thermoelectric power stations, etc., to prevent difficult treatments such as transportation, and dust pollution which is caused by the collapse and weathering of the coarse aggregates or the fine aggregates to fly the fine powder.