Metals and metallurgy Notes

Metals and metallurgy Notes - METALS AND METALS AND...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: METALS AND METALS AND METALLURGY METALLURGY CHAPTER 23 CHAPTER 23 Metallurgy Metallurgy Science and technology of extracting metals from their ores and of compounding alloys. Most metals are found in nature in solid inorganic compounds (minerals) except Au and PGM’s (Pt, Pd, Rh, Ru, Ir, Os) NB source of minerals → oxides (O 2- ), sulphides (S 2- ) and carbonates (CO 3 2- ) Silicates are abundant, BUT they are generally What is involved? Mining (then crushing and grinding) Concentrating the ore → remove the gangue e.g. magnetic separation, flotation, amalgamation Reducing the concentrate to obtain free metal Refining /purifying the metal Alloying → mixing metal with other elements to modify properties 1 2 4 3 5 PYROMETALLURGY PYROMETALLURGY Use high temperatures to alter the mineral chemically and reduce it to the free metal. Requires large amounts of energy + often the source of atmospheric pollution. Used in concentration reduction and refining processes Some pyrometallugical processes Some pyrometallugical processes Calcination: → Heat ore to decompose and eliminate volatile products Carbonates often calcined to drive off CO 2 and form metal oxide e.g. PbCO 3 (s) → PbO(s) +CO 2 (g) ∆ Require temps ~400-500 o C (1000 o C for CaCO 3 ) Hydrated minerals lose H 2 O at ~100-300 o C Roasting: → Themal treatment causes chemical reaction between ore an furnace atmosphere. → Leads to reduction or oxidation (depending on atm) and may be accompanied by calcination....
View Full Document

This note was uploaded on 04/07/2008 for the course GEOLOGY 123 taught by Professor Smith during the Winter '07 term at University of Iowa.

Page1 / 31

Metals and metallurgy Notes - METALS AND METALS AND...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online