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Mining/Environmental Chemistry 5.5, 5.6, 5.7

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Metallurgy Extraction of metals from their rock (ore) Mining the Ore Grinding and primary processing Extractions of metals through chemical processes (floating) Smelting and extraction Purification and physical processing

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Text. p. 214

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It is a chemical reduction reaction that takes place above the melting temperature of the ore minerals. Thus, it produces a liquid, i.e. molten metal. Because ore minerals commonly have impurities, a flux, e.g. limestone, is used to removed the wastes. A wide variety of metals have been obtained by smelting. These include: copper, gold, iron, tin, lead, silver, and mercury

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Bacterial copper ore processing. Water flowing into a bioleaching bath, where copper is extracted from concentrated solutions of copper sulphide ores. Bioleaching uses natural micro-organisms to catalyse the oxidation of sulphide minerals, causing the deposition of copper precipitates (blue). This site is at the open-pit Skouriotissa copper mine, located near Lefka in north-west Cyprus. Mining of copper has taken place here for over 4000 years, with modern techniques including bioleaching and electrolysis. GREEN CHEM

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Wire Bar Sheets

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Waste Metal ions in waste water SO 2 released by smelting Harmful precipitates when mixed with ground water/stream water Tailings 4FeS 2 + 15 O 2 + 2H 2 O 4 Fe 4+ + 8 SO 4 2- + 4 H 1+

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5.6 Cleaning Up Remediation cleaning up land/water so it can be used again Restrict use (Davis Tannery Kingston) Cover/Cap Excavate and replace Treat onsite/off-site

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Bioremediation Use of living things to remove pollutants from contaminated soils Less disruptive More cost efficient Better for environment

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Phytoremediation Use plants to reclaim and repair damaged soils Energy crops can absorb many metals and pollutants and then be use and even the metals can be recovered from the ashes Homework P. 217 Q 1-6 P. 221 Q 1-5