Smelting 1 Oxidation and Reduction: Chemical Weathering and Smelting How do we produce metals from minerals? Chemical Weathering Dissolution H 2 CO 3 + CaCO 3 → Ca 2+ (aq) + 2HCO 3 - (aq) Dissolution of calcite in carbonic acid All rainwater is a weak carbonic acid solution CO 2 (g) + H 2 O (l) ↔ H 2 CO 3(aq) ↔ H + (aq) + HCO 3- (aq) Chemical Weathering Hydrolysis In hydrolysis a molecule is split into two parts by reacting with water. One product includes an OH - from the water molecule, whereas H + is added to another Mg 2 SiO 4 + H 2 O ⇌ 2Mg 2+ (aq) + 4OH - + 4H 4 SiO 4 (aq) Hydrolysis of olivine produces a solution (mineral dissolves) 2KAlSi 3 O 8 + 2H 2 CO 3 + 9H 2 O ⇌ Al 2 Si 2 O 5 (OH) 4 + 4H 4 SiO 4 (aq) + 2K + + 2HCO 3 - Hydrolysis of K-feldspar produces kaolinite (clay product) ) ( 4 4 8 10 4 4 2 8 3 4 4 ) ( 4 8 4 aq K SiO H OH O Si Al H O H O KAlSi ) ( 4 4 8 10 4 4 2 8 3 4 4 ) ( 4 8 4 aq K SiO H OH O Si Al H O H O KAlSi ) ( 4 4 8 10 4 4 2 8 3 4 4 ) ( 4 8 4 aq K SiO H OH O Si Al H O H O KAlSi Silicic Acid (Dissolved Silica) Chemical Weathering Oxidation 4FeS 2 + 15O 2 + 22H 2 O → 4FeO(OH) + 8SO 4 2- + 16H + Oxidation of pyrite to form limonite 4 FeSiO 3(s) + O 2(g) + 8H 2 O → 2Fe 2 O 3(s) + 4H 4 SiO 4(aq) Oxidation and hydrolysis of pyroxene to form hematite
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Smelting
1
Oxidation and Reduction: Chemical Weathering and Smelting
In hydrolysis a molecule is split into two parts by reacting with water. One product includes an OH- from the water molecule, whereas H+ is added to another
Mg2SiO4 + H2O ⇌ 2Mg2+(aq) + 4OH- + 4H4SiO4 (aq)
Hydrolysis of olivine produces a solution (mineral dissolves)