Heat-treated slag

J. T. Way, and T. Twynam heated Thomas slag with soda, and extracted the alkali phosphate with M ater. N. A, Helouis and M. Rychonnet, L. Imperatori, and F. Jean calcined a mixture of the phosphate with sodium sulphate and carbon C. Schwarz, and M. Boblique heated the mineral with iron so as to make ferric phosphate, which was then heated with sodium sulphate and carbon. In each of these cases the alkali phosphate was leached from the mass. M. Drevermann treated the iron phosphate with sodium sulphide, C. Clemm with potassium sulphide. 

Tetronics A process for treating dusts from electrical arc furnaces for making steel and nonferrous metals. Volatile metals (zinc, lead, cadmium) are recovered, and residual slag is nontoxic and suitable for landfill. The dusts, mixed with coal dust and a flux, are fed to a furnace heated by a plasma gun. The metal oxides present are selectively reduced and the vapors of zinc, lead, and cadmium are condensed in a modified Imperial Smelting furnace. Developed by Tetronics Research Development Company, United Kingdom, and first commercialized for steel dusts at Florida Steel, Jackson, TN, in 1989. Seven plants were operating in several countries in 1992. 

The slag is periodically drained off. The molten copper(I) sulfide is drawn off into a Bessemer converter, where it is again heated and treated with air. This oxidizes sulfide ions to SO2 and reduces copper(I) ions to metallic copper. The overall process is... 

Multiple use of treated waste water Multiple use of treated waste water needs to be considered, e.g. using process water from sand preparation in the moulding sand cycle or in slag granulation. The use of cooling water in wet scrubbing may also be considered Use of waste heat for the evaporation of waste water This technique can only be applied when waste heat is available on a continuous basis. A case-by-case evaluation is needed to evaluate its applicability and economic viability... 

The lead is transferred from the CDF to a series of induction-heated steel pots, a softener, and then to a continuous sulphur drossing circuit (CSD). The softener controls the antimony and arsenie at 1.2% and 0.7%, respectively. The remaining copper from the CDF is reduced to less than 0.005% in the CSD. The lead bullion is cast into 3-torme buttons for shipment to the lead refinery. The copper matte and softener slag are treated in downstream plants. 

In the Falconbridge furnace (5,6) it was found that the interface between slag and matte was rendered immobile, probably by the presence of solid chromites. In the Cominco electric furnace, semi-solid precipitates have also been found to be present at the slag/bullion interface therefore, as a first tqjproximation, the interface between slag and bullion was considered to be immobile. Consequently, both sides of the interface were treated as non-slip walls. With this boundaty condition, heat was transferred across the interface only by conduction. Therefore, continuity of the heat flux across the interface was prescribed. Similarly, for electrical power computation, continuity of magnetic vector potential. A, at the interflice was prescribed. 

Table 3 Comparison of distribution between untreated Chlorella and those treated with heat or eluate from slag (% of total algal number) [6]...

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