Frasch sulfur recovery process

Total 1991 world production of sulfur in all forms was 55.6 x 10 t. The largest proportion of this production (41.7%) was obtained by removal of sulfur compounds from petroleum and natural gas (see Sulfurremoval and recovery). Deep mining of elemental sulfur deposits by the Frasch hot water process accounted for 16.9% of world production mining of elemental deposits by other methods accounted for 5.0%. Sulfur was also produced by roasting iron pyrites (17.6%) and as a by-product of the smelting of nonferrous ores (14.0%). The remaining 4.8% was produced from unspecified sources. 

Sulfur can be produced direcdy via Frasch mining or conventional mining methods, or it can be recovered as a by-product from sulfur removal and recovery processes. Production of recovered sulfur has become more significant as increasingly sour feedstocks are utilized and environmental regulations concerning emissions and waste streams have continued to tighten worldwide. Whereas recovered sulfur represented only 5% of the total sulfur production ia 1950, as of 1996 recovered sulfur represented approximately two-thirds of total sulfur production (1). Recovered sulfur could completely replace native sulfur production ia the twenty-first century (2). 

Recovered sulfur has grown steadily in importance as a world source of brimstone since the mid 1950 s. Between 1965 and 1977 recovered sulfur s share of world supply grew from 18% to 30% (D and continues to grow in relation to Frasch mined and other forms of native elemental sulfur. All of this has meant a rapid growth in the number of sulfur recovery facilities and new developments in the various techniques and processes associated with the industry. 

Sulfur is a, relatively abundant element, occurring as an impurity in many metal ores and fossil fuels. It also occurs in relatively pure form from which it can be mined via the Frasch process. Until recently Frasch mining was the major source of supply in the world with the largest producers being the U.S., Mexico and Poland. In the late 1960 s, recovery of sulfur as a by-product from "cleaning" operations began to accelerate rapidly. Sulfur recovery from... 

Traditionally, sulfur has been produced using the Frasch process, in which superheated water (440 K under pressure) is used to melt the sulfur, and compressed air then forces it to the surface. For environmental reasons, the Frasch process is in decline and many operations have been closed. Canada and the US are the largest producers of sulfur in the world, and Figure 15.2 shows the dramatic changes in methods of sulfur production in the US over the period from 1970 to 2001. The trend is being followed worldwide, and sulfur recovery from crude petroleum refining and natural gas production is now of greatest importance. In natural gas, the source of sulfur is H2S which occurs in concentrations of up to 30%. Sulfur is recovered by reaction... 

Sulfur is commercially recovered from wells sunk into the salt domes along the Gulf Coast of the U.S. Using the Frasch process, heated water is forced into the wells to melt the sulfur, which is then brought to the surface. Sulfur also occurs in natural gas and petroleum crudes and must be removed from these products. Formerly, this was done chemically, which wasted the sulfur new processes now permit recovery. Large amounts of sulfur are also recovered from Alberta gas fields. 

Sulfur is mined by the recovery method known as the Frasch process, which was invented by Herman Frasch in Germany in the early 1900s. This process forces superheated water, under pressure, into deep underground sulfur deposits. Compressed air then forces the molten sulfur to the surface, where it is cooled. There are other methods for mining sulfur, but the Frasch process is the most important and most economical. 

Elemental sulfur is recovered from its ore deposits found throughout the world. It is obtained commercially by the Frasch process, recovery from wells sunk into salt domes. Heated water under pressure is forced into the underground deposits to melt sulfur. Liquid sulfur is then brought to the surface. Sulfur is recovered by distillation. Often the ore is concentrated by froth flotation. 

Frasch develops process for recovery of sulfur Rhombohedral sulfur established as Sg... 

Frasch process the recovery of sulfur from underground deposits by melting it with hot water and forcing it to the surface by air pressure. (19.6)... 

Fig. 15.2 Production of sulfur in the US from 1970 to 2001 note the increasing importance of recovery methods which have now replaced the Frasch process as a source of sulfur in the US. [Data US Geological Survey.]...

The Herman Frasch Process for recovery of sulfur from underground salt domes is commercialized... 

Frasch process An industrial process for the recovery of sulfur that uses superheated water to liquefy sulfur deposits in Earth s crust and bring the molten sulfur to the surface. (22.8)... 

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