Cotreatment of sewage and steelworks wastes
AssigneeIllawarra Technology Corporation Limited
InventorHoward K. Worner
Life of this patent
Estimating the term…
Abstract
Steelworks dusts or sludge is mixed into sewage preferably in the presence of a flocculating agent to provide a rapid separation of a clear effluent and a sludge which is dewatered and dried to form a solid material adapted to entrap harmful materials in the sewage such as heavy metals, pathogens and organic chemicals. The solid material is supplied to a smelt reduction furnace from which molten iron is recovered and a hot gas discharge is provided from which recovery of zinc and other materials may be achieved, other waste material being removed as a slag.
Claims15
A method of processing sewage having a liquid portion including water and a solid portion including carbon-containing compounds and steelworks dusts having metal values, said method comprising the steps of mixing the steelworks dusts and the sewage to form a mixtures, processing the mixture to separate out the water from the liquid portion of said sewage and leaving a wet sludge containing substantially all of the carbon containing compounds from the solid portion of said sewage and substantially all of the metal values of said steelworks dusts, dewatering and drying the sludge to provide a solid composite material, supplying the composite material to a smelt reduction furnace and smelting the material to reduce the metal values in the sludge to molten metal and to combust the carbon-containing compounds in the sludge to produce an off gas and collecting the metal values.
A method as claimed in claim including adding lime, the lime providing a source of calcium for slag formation during the step the composite material.
Dependencies are inferred from the claim text.