Steel used for many different applications is more and more often coated with zinc for corrosion protection purposes. The growing amount of Electric Arc Furnace Dust (EAFD) generated during the production of steel requires treatment that is able to convert this dust into usable materials. The current state of the art for the treatment of these wastes is based on the use of a Waelz Kiln, or any other zinc fuming system, where the zinc contained in the EAFD is concentrated in Crude Zinc Oxide (C.Z.O.), which is then fed to sulfate electrowinning or to the Imperial Smelting Process to produce zinc metal. These two processes require that the C.Z.O. be pre-treated, or at least washed, to meet the requirements of the processes. Engitec developed the EZINEX Ò Process that is able to convert C.Z.O. and other zinc oxides directly to metallic zinc cathodes. Engitec also studied the INDUTEC Ò Process, a pyrotechnology competitive to the Waelz Kiln. The INDUTEC Ò /EZINEX Ò Integrate Process will be described.

OverviewLead and ZincEditor's Note: A hypertext-enhanced version of this article can be found at www.tms.org/pubs/journals/JOM/ 0304/Ojebuoboh-0304.htmlThis article describes the development of a new process in which lead bullion obtained from smelting concentrates is refined by leachingelectrowinning. In the last half century, the challenge to treat and refine lead in order to minimize emissions of lead and lead compounds has intensified. Within the primary lead industry, the treatment aspect has transformed from the sinter-blast furnace model to direct smelting, creating gains in hygiene, environmental control, and efficiency. The refining aspect has remained based on kettle refining, or to a lesser extent, the Betts electrolytic refining. In the mid-1990s, Asarco investigated a concept based on granulating the lead bullion from the blast furnace. The granular material was fed into the Engitec Fluobor process. This work resulted in the operation of a 45 kg/d pilot plant that could produce lead sheets of 99.9% purity.

No abstract

No abstract

No abstract