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vapor impurities. In order to remove the lead 2-3% of the vapor is condensed, which draws the majority of the lead out of the vapor; down to the point where it is only 0.003% of the total contents. Finally the vapor is pumped into the cadmium column where it is cooled to an intermediate temperature
68:. Therefore, in the first column the zinc is heated above its boiling point and allowed to rise to a condenser. The iron and aluminium impurities sink to the bottom in the form of a solid or liquid. There are still
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below the boiling point zinc, but still above the boiling point of cadmium (767 °C (1,413 °F)). The zinc leaves out the bottom as a refined liquid, while the cadmium leaves out the top as vapor.
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The process take advantage of the relatively low boiling point of zinc (907 °C (1,665 °F)) as compared to the impurities being removed in the first "column":
27:(SHG) zinc, which is at least 99.995% pure. This process is not usually required when smelting of zinc is done through
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There are various refining methods, but the refluxing process is the most commonly used.
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Zinc
Handbook: Properties, Processing, and Use in Design
41:High purity zinc is required industrially to avoid
31:processes, but is needed when zinc is produced by
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112:"London Metal Exchange: LME Zinc Physical"
35:processes, because it is only 98.5% pure.
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57:invented this process in 1930.
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139:, CRC Press, pp. 21–22,
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19:is the process of purifying
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164:Metallurgical processes
55:New Jersey Zinc Company
133:Porter, Frank (1991),
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49:Refluxing process
33:pyrometallurgical
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116:www.lme.com
158:Categories
98:References
66:aluminium
43:zinc pest
81:See also
127:Sources
74:cadmium
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92:ZAMAK
169:Zinc
141:ISBN
72:and
70:lead
64:and
62:iron
53:The
21:zinc
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