Contact Process
CONTACT PROCESS Sulfuric acid is one of the most important industrial chemicals Outline three uses of sulfuric acid in industry
1. The major use of sulfuric acid in Australia is in the manufacture of fertilizers such as ammonium sulfate and superphosphate. Superphosphate is produced by reacting sulfuric acid with rock phosphate. Ammonium sulfate is produced by neutralising ammonia with sulfuric acid. 2. Production of titanium (IV) oxide from titanium minerals eg ilmenite. Titanium is an important lightweight metal used to produce strong alloys and white, opaque pigments. H2SO4 is used to leach the titanium from the minerals after mining. 3. Cleaning iron – because very corrosive used to remove the oxide layer from iron or steel before they are galvanised or electroplated. Describe the processes used to extract sulfur from mineral deposits, identifying the properties of sulfur which allow its extraction and analyzing potential environmental issues that may be associated with its extraction Most sulphur is extracted from mineral deposits using the Frasch process. Superheated stream is pumped down the outer of 3 concentric pipes into the sulphur deposit, and since sulphur has a low melting point (119) it is readily melted. At the same time, compressed air is blown down the inner pipe, and because sulphur has a relatively low density, the air is able to force the molten sulphur up the middle pipe to the surface where it resolidifies. The insolubility of sulphur in water means that it separates from any water, leaving 99.5% pure sulphur. Sulfur is also obtained from hydrogen sulphide in natural gas and petroleum. Incomplete combustion of H2S in a furnace produces SO2 and S. 3H2S(g) + O2(g) H2S(g) + 3S(g) + SO2(g) The mixture is cooled to condense the sulphur. Sulfur is also released as sulphur dioxide when metal sulphide ores are smelted. Eg. ZnS(s) + O2(g) Zn(s) + SO2(g)
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Environmental Issues: - Sulfur is easily oxidised to sulphur dioxide
1. The major use of sulfuric acid in Australia is in the manufacture of fertilizers such as ammonium sulfate and superphosphate. Superphosphate is produced by reacting sulfuric acid with rock phosphate. Ammonium sulfate is produced by neutralising ammonia with sulfuric acid. 2. Production of titanium (IV) oxide from titanium minerals eg ilmenite. Titanium is an important lightweight metal used to produce strong alloys and white, opaque pigments. H2SO4 is used to leach the titanium from the minerals after mining. 3. Cleaning iron – because very corrosive used to remove the oxide layer from iron or steel before they are galvanised or electroplated. Describe the processes used to extract sulfur from mineral deposits, identifying the properties of sulfur which allow its extraction and analyzing potential environmental issues that may be associated with its extraction Most sulphur is extracted from mineral deposits using the Frasch process. Superheated stream is pumped down the outer of 3 concentric pipes into the sulphur deposit, and since sulphur has a low melting point (119) it is readily melted. At the same time, compressed air is blown down the inner pipe, and because sulphur has a relatively low density, the air is able to force the molten sulphur up the middle pipe to the surface where it resolidifies. The insolubility of sulphur in water means that it separates from any water, leaving 99.5% pure sulphur. Sulfur is also obtained from hydrogen sulphide in natural gas and petroleum. Incomplete combustion of H2S in a furnace produces SO2 and S. 3H2S(g) + O2(g) H2S(g) + 3S(g) + SO2(g) The mixture is cooled to condense the sulphur. Sulfur is also released as sulphur dioxide when metal sulphide ores are smelted. Eg. ZnS(s) + O2(g) Zn(s) + SO2(g)
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Environmental Issues: - Sulfur is easily oxidised to sulphur dioxide