Method for the non-leachable immobilisation of molybdenum compounds in a slag

摘要

A method for the non-leachable immobilisation of molybdenum compounds in a slag by melting and subsequently cooling waste streams containing iron and molybdenum compounds, where: the treatment temperature is above the liquidus temperature of the slag; the oxygen pressure is adjusted to a value of between 10-6 and 10-12 bar; the thermodynamic activity of Fe (I) in the slag is e"0. 5; the Fe (III)/Fe (II) ratio in the slag is between 0.25 and 2; and after tapping off, the resultant slag is cooled such that a solid solution of MoO2 in a spinel structure which exhibits a very low leaching value for molybdenum is obtained. Such a slag that is obtained by the above method can be used as material in the construction industry.