METHOD FOR RECYCLING WASTE WATER FROM A STAINLESS STEEL SLAG TREATMENT PROCESS

摘要

The present invention relates to method for recycling alkaline waste water from a stainless steel slag treatment process wherein stainless steel slag is brought into contact with water thereby producing said waste water, which waste water contains heavy metals, including at least chromium, and has a pH of at least 12. The waste water is recycled by using it for treating an alkaline granular carbonatable material, which contains aluminum metal, in order to oxidize the aluminum metal contained therein. This material is in particular municipal waste incinerator bottom ash which can, after the treatment of the present invention, safely be used as fine or coarse aggregate in bonded applications such as concrete, mortar and asphalt. During the treatment with the alkaline waste water, hydrogen gas is produced which is captured and used to produce energy by means of a cogeneration device.