The slag-fuming process basically depends on the re- duction of zinc oxide by carbon monoxide produced by the combustion of fine coal as per equation (4). This reducing reaction is highly endothermic . The heat necessary for the production of one gram-atom of zinc at about 1200 C is of the order of 43 Kcal.
There is only one day of capacity between the zinc fume recovery process in the smelter and the fume leach process in the zinc plant.Therefore, if there is an upset in the leach circuit, it is necessary to stop the slag fuming process for zinc recovery and stockpile smelter slag for recovery in the future. The same is true for the flow of residue from the zinc plant circuits to the smelter.
The kinetics analysis has been based on model predictions of fuming efficiency (Zn/coal) of the coal particles injected into the slag. The model predicts that fuming efficiency passes through a maximum with increasing residence time of coal particles in the slag.
Usually it is recovered from residues obtained from zinc extraction. The residues, slags, fume, or dusts from zinc smelting or lead-zinc smelting are treated with a mineral acid. Other steps involved in recovery often vary, but mostly use solvent extraction and precipitation steps.
· FUNDAMENTALS OF ZINC RECOVERY FROM METALLURGICAL WASTES IN THE ENVIROPLAS PROCESS Masud A. Abdel-latif Mintek Randburg Republic of South Africa. granulated slag stockpiled in dumps can be directly charged into the fuming furnace.. thus lower ZnO in the final slag and to enhanced zinc fuming rates. Changes to slag basicity can be.
Pilot-scale testwork has proven the technical feasibility of the Enviroplas process for the recovery of zinc from EAF dust and LBF slag. The produced slag consistently met the USA EPA TCLP test for safe disposal. Very good zinc extraction, fuming rates, and condensation efficiency were achieved during the testwork.
The slag fuming process has become operativ since e 1930s to recover zinc fro m lead blas furnact e slag . Th e first sla fuming operatiog wan commences bdy th e Anaconda Copper Mining Co., at East Helena, Montana in 1927 Sinc. thee thn slae fuming operatiog wans accomplished wit succesh bys th use oe f a reducing
Typically, EAF dust requires a smelting temperature of about 1500-1550OC in order to achieve a ZnO content in the final slag of 2% and lower. In comparison, LBF slag demands an operating temperature of 1400-1450OC to extract more than 85% of the contained zinc at good fuming rates (Figure 3).
In typical zinc & lead production operations, lead blast furnace slags and zinc leaching residues are usually fumed to recover zinc metal. Regardless of the fuming methods employed, the tail slag from zinc fuming furnaces still contains about 3 per cent or more zinc and some trace amounts of elements such as lead, indium and germanium.
zinc processing, the extraction of zinc from its ores and the preparation of zinc metal or chemical compounds for use in various products. Zinc (Zn) is a metallic element of hexagonal close-packed (hcp) crystal structure and a density of 7.13 grams per cubic centimetre. It has only moderate hardness and can be made ductile and easily worked at temperatures slightly above the ambient.
Continuous Fuming of Zinc-Bearing Residues: Part II. ... The Submerged-Plasma Zinc-Fuming Process. Metallurgical and Materials Transactions B, 2007. Evgueni Jak. Peter Hayes. Karel Verscheure. Maurits Van Camp. ... On the Microstructure of a Freeze Lining of an Industrial Nonferrous Slag. By Patrick Wollants. Metallurgical Furnaces. By Pedro ...
The Fuming process is applied to comprehensively recycle lead-antimony blast furnace slag.Slag is fed in fuming furnace in the form of cold particulate Each period costs1.5~2.5 hours.when the fuming temperature reaches 1,250 ℃ and the reduction smelting time lasts 2 hours,the majority of useful metals can be recovered as metal oxide with the product rate around 14 %.And the derelict slag can ...
In the fuming stage, only hot slag is treated, and the heat consumption is mainly lead and zinc reduction,volatilization heat absorption, and furnace heat loss. Therefore, the energy consumption in the fuming stage is low. Process Flow Zinc residues are fumed in SSC + FF.
With dropping zinc concentration in the slag, the mass flux of zinc oxide to the secondary bubble decreases and within a given time interval, less zinc oxide relative to ferric iron is reduced. Thus the maximum fuming efficiency declines and the time taken to reach the maximum increases.
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the recovery of metal from the slag in subsequent processing. Holding of the slag at temperature permitted the recovery of much of the metallic lead as vapor and some small recovery of zinc as fume. When copper was used as a getter, more zinc and lead were recovered. In electrorefining, lead recovery was much higher than that in
This collection features contributions covering the advancements and developments of new high-temperature metallurgical technologies and their applications to the areas of processing of minerals; extraction of metals; preparation of metallic, refractory and ceramic materials; treatment and recycling of slag and wastes; and saving of energy and ...
Made available by U.S. Department of Energy Office of Scientific and Technical Information ...
GA Yurko, " Slag Fuming Process at the Cominco Smelter ", in Extractive metallurgy of lead and zinc, CH Catterill (ed.), Vol.2, AIME, New York, 1970,p. 330-347 * Calculated value
Typically, EAF dust requires a smelting temperature of about 1500-1550 °C in order to achieve a ZnO content in the final slag of 2% and lower. In comparison, LBF slag demands an operating temperature of 1400-1450 °C to extract more than 85% of the contained zinc at good fuming rates ( Fig. 3 ). Download : Download full-size image Fig. 3.