The Waelz process is the oldest and most often applied technology for the recycling of dusty steel mill residues worldwide,especially for EAF dust.It is a pyro-metallurgical process characterized by the volatilization...The Waelz process is the oldest and most often applied technology for the recycling of dusty steel mill residues worldwide,especially for EAF dust.It is a pyro-metallurgical process characterized by the volatilization of non-ferrous metals like zinc,lead and cadmium out of an oxidised solid mixture by means of reduction by coke in a rotary kiln without generating a liquid slag.The recycling of EAF dust closes the material loop between the steel and the zinc industry.Nowadays still more than 50%of the generated EAF dust is lost by sending it to landfill, which means an annual loss of about 800000 t of zinc. The paper gives a short overview about all known recycling techniques for EAF dust before describing in detail the Waelz process.A state-of-the-art Waelz plant fulfils all requirements for environmental protection.It can be operated free of waste water,with low diffuse dust emission and with very low atmospheric emission.The release of heavy metals or dioxin is well controlled by appropriate techniques.At the end of the paper some estimative figures are presented concerning capital expenditure and operating costs.For more precise figures a detailed study is required taking into account the size of the plant and the local conditions.展开更多
文摘The Waelz process is the oldest and most often applied technology for the recycling of dusty steel mill residues worldwide,especially for EAF dust.It is a pyro-metallurgical process characterized by the volatilization of non-ferrous metals like zinc,lead and cadmium out of an oxidised solid mixture by means of reduction by coke in a rotary kiln without generating a liquid slag.The recycling of EAF dust closes the material loop between the steel and the zinc industry.Nowadays still more than 50%of the generated EAF dust is lost by sending it to landfill, which means an annual loss of about 800000 t of zinc. The paper gives a short overview about all known recycling techniques for EAF dust before describing in detail the Waelz process.A state-of-the-art Waelz plant fulfils all requirements for environmental protection.It can be operated free of waste water,with low diffuse dust emission and with very low atmospheric emission.The release of heavy metals or dioxin is well controlled by appropriate techniques.At the end of the paper some estimative figures are presented concerning capital expenditure and operating costs.For more precise figures a detailed study is required taking into account the size of the plant and the local conditions.
