Zinc refining

Zinc refining is the process of purifying zinc to at least 99.995% pure (SHG zinc). This process isn't usually required when smelting zinc through electrolysis processes, but is needed when zinc is produced by pyrometallurgical processes, because it is only 98.5% pure.

There are various refining methods, but the refluxing process is the most commonly used.

Refluxing process

The New Jersey Zinc Company invented this process in 1930.

The process take advantage of the the relatively low boiling point of zinc (convert|907|C|F) as compared to the impurities being removed in the first "column": iron and aluminium. Therefore, in the first column the zinc is heated above its boiling point and allowed to rise to a condenser. The other impurities sink to the bottom in the form of a solid or liquid. There is still lead and cadmium, in the form of 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 below the boiling point zinc, but still above the boiling point of cadmium (convert|767|C|F). The zinc leaves out the bottom as a refined liquid, while the cadmium leaves out the top as vapor.

ee also

*Zinc smelting


*Citation | last = Porter | first = Frank | title = Zinc Handbook: Properties, Processing, and Use in Design | publisher = CRC Press | pages = 21-22 | year = 1991 | url = http://books.google.com/books?id=laACw9i0D_wC | isbn = 0824783409.

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Zinc smelting — is the process of converting zinc concentrates (ores that contain zinc) into pure zinc. The most common zinc concentrate processed is zinc sulfide,Citation | title = Compilation of Air Pollutant Emission Factors | publisher = U.S. Environmental… …   Wikipedia

  • Refining (metallurgy) — Refining (as in non metallurgical uses) consists of purifying an impure material, in this case a metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material …   Wikipedia

  • zinc processing — Introduction       preparation of the ore 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 …   Universalium

  • Zinc — This article is about the metallic element. For other uses, see Zinc (disambiguation). copper ← zinc → gallium ↑ Zn ↓ Cd …   Wikipedia

  • zinc — zincky, zincy, zinky, adj. zincoid, adj. /zingk/, n., v., zincked or zinced /zingkt/, zincking or zincing /zing king/. n. 1. Chem. a ductile, bluish white metallic element: used in making galvanized iron, brass, and other alloys, and as an… …   Universalium

  • Silver — This article is about the chemical element. For the color, see Silver (color). For other uses, see Silver (disambiguation). palladium ← silver → cadmium …   Wikipedia

  • Dony, Jean-Jacques Daniel — SUBJECT AREA: Metallurgy [br] b. 24 February 1759 Liège, Belgium d. 6 November 1819 Liège, Belgium [br] Belgian inventor of the horizontal retort process of zinc manufacture. [br] Dony trained initially for the Church, and it is not known how he… …   Biographical history of technology

  • Severočeský — ▪ region, Czech Republic also called  Severní Čechy , English  Northern Bohemia        kraj (region), northwestern Czech Republic. It is the smallest of the country s regions. Severočeský is bounded on the north by Germany and Poland, on the east …   Universalium

  • Cadmium oxide — chembox new ImageFile = ImageSize = IUPACName = Cadmium oxide OtherNames = Cadmium(II) oxide, Cadmium monoxide Section1 = Chembox Identifiers Abbreviations = CASNo = 1306 19 0 EINECS = PubChem = SMILES = InChI = RTECS = EV1925000 MeSHName = ChEBI …   Wikipedia

  • cad|mi|um — «KAD mee uhm», noun. a soft, bluish white chemical element, resembling tin, used in plating, to prevent corrosion, and in making alloys. It is a ductile metal and occurs only in combination with other elements. »Cadmium is produced as a by… …   Useful english dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.