Sulphur as a practical element applied in production of various products including sulfuric acid, agricultural fertilizers, rubber, match stick, dye and etc. is considered widely by chemists to find novel ways and facilities for improving sulphur extraction. Sulphur manufacturers can produce sulphur in three main ways which are mentioned in detail bellow:
- Producing sulphur from sediments:
The majority of the earth’s sulphur is stored underground in rocks and minerals; therefor producing sulphur from sediments is a traditional and common way that is applied by some sulphur manufacturers. In this method, sulphur is extracted from the deep sediments of calcareous layers that consist sulphur through the frash process.
Preheat water (165 C) is transferred to the layers of sediment by the outer tube of three concentric tubes, causing sulphur to be melted. Compressed air is injected through the central tube downward, guiding the melted sulphur upside by pressure through the mid tube. This process is applicable for the depth of 80 meters underground and each well can produce about 300 MT per day. If the sediments are located near the earth’s surface (low depth) we can extract the sulphur ores. In this method, it is possible to produce sulphur from sulphur ores through a melting process in which the required heat is supplied through the sulphur burning. Also producing sulphur from the mentioned sediments is possible through distillation in temperatures above 440 C.
2. Producing sulphur from H2S:
The second source of sulphur is H2S, mainly is found in natural gas, gases produced from refinery, synthesis gas, and exhaust gases in coke production. H2S is extracted from the mentioned gases through physical and chemical gasification for example with ethanol amine. Then the retrieval absorbent liquid is changed to sulphur through the common Claus process, invented by Carl Friedrich Claus (German chemist). Hydrogen sulfide changes to sulphur through its reaction with air or oxygen and heat. This is an exothermic reaction and its efficiency is 60% to 70%:
First the cooling process is done on reaction gases of combustion chamber in waste heat boilers, to make the temperature to 300 C. Then the conversion process continued in a reactor full of cobalt catalyst with base of alumina. The efficiency is 85%. After the compression process and producing sulphur in temperatures under 170 C, the reaction gases are changed to sulphur on active aluminum oxide in a secondary reactor (if necessary in third reactor) and 220 C. The efficiency of this level is 96%~98%. Sulphur amount in extra gases should be reduced to 10 PPM through gasification. Unlike the classic Claus process, in which the oxygen content in air does not exceed 30%, in base Claus process, the oxygen content is increased to 80% or even 100%. In 1985 this process was operated on a large industrial scale. This process is beneficial as it reduces the waste gases up to 35% in comparison to classic Claus process.
It should be noted that producing sulphur from H2S is a famous economic way appreciated by many sulphur manufacturers. Amoot Iranian Trading Company as a well-known sulphur supplier, can provide extracted sulphur from H2S for customers anywhere in the globe. Various kinds of processed sulphur including yellow sulphur powder, sulphur granules, prilled, and lumps are available at our company.
- Producing sulphur from pyrite:
Sulphur and melted sulfide iron are produced by heating the pyrite iron to 1200 C and in absence of air. Some sulphur manufacturers apply this method to produce sulphur but it is not a common way.