Secondary metal production

S 111 fi 1 r-reco ve ry p lants Carbon-black plants (furnace process) Primary lead smelters Fuel-conversion plants Sintering plants Secondary metal-production plants Chemical-process plants ... 

Secondary metals production may refer to secondary metal extraction or to secondary alloy production. Secondary metal extraction normally extracts one metal from the waste and sells any valuable by-products to other metal extractors or chemical processors. In secondary alloy production, the scrap is blended and refined so as to yield an alloy of the desired chemistry. In both cases it is necessary to deal with various sizes, shapes, and compositions of waste materials and the processing route adopted moreover, the plant where the process is implemented should have sufficient flexibility to handle such widely varying input material. 

Secondary metal production is advantageous not only with respect to energy consumption but also to environmental impact as compared to primary metal production. The important environmental problems pertain to the formation of dioxins during thermal processing and the generation of dusts of the oxides of zinc, lead, and other metals in secondary steel, copper, and zinc production. 

The second bright yellow band separates from the third yellow band with 15% benzene-hexane. Removing the solvent and recrystallizing the residue from dichloromethane-hexane yields the secondary metallation products 2 (0.08g, O.lOmmol) and 3 (0.12g, 0.14mmol), respectively. These are the phosphine-substituted derivatives of the secondary metallation product described below. The yield of these two products may be maximized by heating the starting complex in the absence of solvent to 145 °C (whereupon it melts) for 15 to 20 min. 

Secondary metal-production plants Chemical-process plants... 

McKinney and Kaesz reacted [Re(CHj)(CO)5] with orthometallation products of alkyl manganesepentacarbonyls to yield bis(tetracarbonyl-metal) secondary metallation products (161), as shown in Scheme II. 

An economic evaluation of expanding secondary metal production facilities to support the timely growth in tellurium and indium production. This should also include further assessments of the economically recoverable tellurium and indium resource bases. 

Metal recovery from industrial-process-flow residues from primary and secondary metal production. 

In the discussion on the re-use of dust and residues, no information was provided on treatment or re-use techniques for dust from induction furnace melting, for dross from aluminium melting, fettling dusts, abrasives or for blasting grit, although a re-use of most of these materials into secondary metal production is possible. 

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