Frasch producers

Therefore, we believe that the cost position of Frasch producers will determine the trend in sulfur prices, so long as the Frasch industry remains the marginal supply source - a condition that will continue over the forecast period. If, at some future date, the supplies of by-product sulfur reach a level which will fully satisfy the demand, this assumption may no longer be valid. 

The most effective and economic method of extracting sulfur from native deposits in situ under suitable conditions is the Frasch process [74]. The process involves injecting hot water directly into the sulfur deposit and then pumping the molten sulfur to the surface. The sulfur is then pumped to storage areas where it solidifies. In this way, blocks of pure sulfur are obtained. Frasch-produced sulfur can be quite pure (99.7%-99.8%) and light yellow in color. If the sulfur is associated with small amounts of bituminous residues, it is brown or blackish. This so-called dark sulfur may contain up to 1% carbon, mainly present as complex organic sulfur. The United States, Poland, and Iraq practice Frasch sulfur production on a commercial scale, as did Mexico until 1993. 

The War protected Europe from Frasch sulfur and global demand surged. Even so, this was a diffrcult year for the industry. Labor trouble and restrictions on fuel supply depressed production. In 1918, the term of COISS was renewed. After the war, the Sicilian industry was back on hard times. Trans-Atlantic vessel rates dropped, allowing the U.S. Frasch producers to be even more competitive in Europe. The two major markets, Britain and France, had switched mainly to American product. In 1921, the Italian government intervened to save the Mtering business, a feature that the Sicilian sulfur industry would henceforth be dependent upon to survive. 

As the number of sour gas plants escalated, so did the number of competitors. Canada had to start selling their sulfur, and competing against the Frasch producers was no easy task. In the early days of the industry, Canadian producers had two serious competitive disadvantages ... 

Logistics to get the sulfur overseas, the sulfur had to be transported to Vancouver, while the Frasch producers were already near ocean-going ports. 

The problem was that demand was fickle and production, oblivious to sulfur markets, just kept on increasing. There was some movement among Frasch producers. With the lower price, many Frasch mines in the U.S. closed. In 1971, the number was down to thirteen. While there was a major decline in the number of U.S. Frasch mines, there was only a nominal impact on production as the closures were generally smaller mines. Over 70% of the production came from the five largest mines. 

Poland surpassed the U.S. as the largest Frasch producer in the world. 

Frasch producers was likely so insurmountable that the outcome was inevitable. We will never know for sure, though, because the Sicilian companies never even tried. Here lies the criticism and the difference between the British Leblane and Sicilian sulfur industries. The former scratched and clawed to survive, while the Sicilian sulfur businesses laid down and pitifiilly awaited their destiny. 

On the other hand, a growing supply of sulfur is now obtained from sour natural gas and sour petroleum as recovered sulfur. Either existing hydrogen sulfide is carefully oxidized into sulfur or hydrogen gas is used to convert the sulfur in petroleum into hydrogen sulfide, which is then carefully oxidized to sulfur under controlled conditions. This source of supply for sulfur has been growing faster than Frasch-produced sulfur and is now the largest sulfur source in the world. 

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. 

Production of Frasch and native sulfur probably peaked in the CIS at about 3.2 million metric tons. It has declined since and was reported as 400,000 metric tons in 1995. About 200,000 metric tons was produced in the Ukraine, with the remainder from Turkmenistan and Russia. 

Sulfur is produced from a variety of sources using many different techniques in many countries around the world. Worldwide changes have affected not only the sources of sulfur, but also the amounts consumed. Sulfur sources in the United States underwent significant changes during the 1980s. Voluntary sulfur from the Frasch process (mines) suppHed only 25% of the sulfur in the United States in 1995, compared to about 53% in 1980, whereas recovered or involuntary sulfur suppHed 63% of the sulfur in the United States in 1995, compared to 34% in 1980. About 12% is suppHed from other forms, primarily by metallurgy (21,33). 

Sulfuric acid is the most important sulfur-containing intermediate product. More than 85% of the sulfur consumed in the world is either converted to sulfuric acid or produced direcdy as such (see Sulfuric acid and sulfur trioxide). Worldwide, well over half of the sulfuric acid is used in the manufacture of phosphatic fertilizers and ammonium sulfate for fertilizers. The sulfur source may be voluntary elemental, such as from the Frasch process recovered elemental from natural gas or petroleum or sulfur dioxide from smelter operations. 

Two principal factors affected the U.S. sulfuric acid industry in the 1980s. The first was the increased availabiUty of recovered sulfur vs Frasch sulfur (see SuLFURREMOVAL AND recovery). This occurred because of environmental concerns and regulations forcing more sulfur to be recovered at refineries, power plants, etc. The effect of this change was that the cost of sulfur in the marketplace became driven largely by the cost of nonsulfur industries, rather than by the traditional discretionary sulfur producers, and tended to stabilize U.S. sulfur prices. 

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). 

A Frasch mine can produce as much as 2.5 million tonnes of sulfur per annum- Such massive operations clearly require huge quantities of mining water (up To 5 million gallons daily) and abundant pou er supplies for tlie drilling, pumping and superheating operations. 

The Frasch process, developed in 1894, produces sulfur from underground deposits. 

The origin of the small Sy content of all commercial sulfur samples is the following. Elemental sulfur is produced either by the Frasch process (mining of sulfur deposits) or by the Claus process (partial oxidation of HyS) [62]. In each case liquid sulfur is produced (at ca. 140 °C) which at this temperature consists of 95% Ss and ca. 5% other sulfur homocycles of which Sy is the main component. On slow cooling and crystalhzation most of the non-Ss species convert to the more stable Ss and to polymeric sulfur but traces of Sy are built into the crystal lattice of Ss as sohd state defects. In some commercial samples traces of Ss or Sg were detected in addition. The Sy defects survive for years if not forever at 20 °C. The composition of the commercial samples depends mainly on the coohng rate and on other experimental conditions. Only recrystalhzation from organic solvents removes Sy and, of course, the insoluble polymeric sulfur and produces pure a-Ss [59]. 

Elemental sulfur1-4 occurs naturally in association with volcanic vents and, in Texas and Louisiana, as underground deposits. The latter are mined by injecting air and superheated water, which melts the sulfur and carries it to the surface in the return flow (the Frasch process). Most of the sulfur used in industry, however, comes as a by-product of the desulfurization of fossil fuels. For example, Albertan sour natural gas, which often contains over 30% (90%, in some cases) hydrogen sulfide (H2S), as well as hydrocarbons (mainly methane) and small amounts of C02, carbonyl sulfide (COS), and water, is sweetened by scrubbing out the H2S and then converting it to elemental S in the Claus process.5 The Claus process is applicable in any industrial operation that produces H2S (see Section 8.5) it converts this highly toxic gas to nontoxic, relatively unreactive, and easily transportable solid sulfur. 

Pyrite is the most abundant of the metal sulfides. For many years, until the Frasch process was developed, pyrite was the main source of sulfur and, for much of the first half of the twentieth century, comprised over 50% of world sulfur production. Pyrite reserves are distributed throughout the world and known deposits have been mined in about 30 countries. Possibly the largest pyrite reserves in the world are located in southern Spain, Portugal, and the CIS. Large deposits are also in Canada, Cyprus, Finland, Italy, Japan, Norway, South Africa, Sweden, Turkey, the United States, and Yugoslavia. However, the three main regional producers of pyrites continue to be Western Europe Eastern Europe, including the CIS and China. 

---