Sulfur dioxide from metallurgy

Use Building stone, metallurgy (flux), manufacture of lime, source of carbon dioxide, agriculture, road ballast, cement (Portland and natural), alkali manufacture, removal of sulfur dioxide from stack gases and sulfur from coal. 

The citrate process was developed specifically for the removal of sulfur dioxide from smelter gases by the Salt Lake City Metallurgy Researdi Cmiter of the U.S. Bureau of Mines (Rosenbaum et al., 1973). The absorbent is an aqueous solution containing tqiproximately 190 g of citric acid and 80 g of sodium carbonate per liter, and is capable of absorbing 10 to 20 g of sulfur dioxide per liter. 

In mineral technology, sulfur dioxide and sulfites are used as flotation depressants for sulfide ores. In electrowinning of copper from leach solutions from ores containing iron, sulfur dioxide prereduces ferric to ferrous ions to improve current efficiency and copper cathode quaHty. Sulfur dioxide also initiates precipitation of metallic selenium from selenous acid, a by-product of copper metallurgy (326). 

The environmental problem of sulfur dioxide emission, as has been pointed out, is very much associated with sulfidic sources of metals, among which a peer example is copper production. In this context, it would be beneficial to describe the past and present approaches to copper smelting. In the past, copper metallurgy was dominated by reverberatory furnaces for smelting sulfidic copper concentrate to matte, followed by the use of Pierce-Smith converters to convert the matte into blister copper. The sulfur dioxide stream from the reverberatory furnaces is continuous but not rich in sulfur dioxide (about 1%) because it contains carbon dioxide and water vapor (products of fuel combustion), nitrogen from the air (used in the combustion of that fuel), and excess air. The gas is quite dilute and unworthy of economical conversion of its sulfur content into sulfuric acid. In the past, the course chosen was to construct stacks to disperse the gas into the atmosphere in order to minimize its adverse effects on the immediate surroundings. However, this is not an en-... 

T he citrate process for the recovery of elemental sulfur from sulfur dioxide emissions in waste gas was conceived by Bureau of Mines investigators at the Salt Lake City Metallurgy Research Center in their initial laboratory research reported in 1970 (I). This work led to a scale-up of the process to a 400 cu ft/min (CFM) pilot unit which began treating reverberatory furnace gas at a copper smelter in Arizona in November 1970. While a series of mechanical difficulties allowed only... 

The main sources of harmful substances emissions, i.e., dust, SO and CO2 in the air, are the processing plants for coke, briquettes, coals, the thermal power stations, air, water, and road transport [9]. The exhaust gases contain also, CO, organic and inorganic compounds, etc. [10]. Dust, sulfur dioxide, carbon dioxide, nitrogen oxides and organic compounds, etc. are the main pollutants released in the environment from metallurgy. 

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