So basically, the whole point of this process is to extract elemental sulfur from underground deposits. Is this process essentially correct or am I missing out certain details?
- Firstly, three concentric pipes are placed into the underground sulfur deposit
- Then, water that has been superheated is pressurised into the sulfur deposit through the outermost pipes.
- The result of the above is melted sulfur stuck in the ground in an emulsion. The pressure of the chamber is also increased (i don't know why?)
- To get it out of the ground, compressed air is injected through the innermost pipe: this forces the sulfur-water emulsion to the surface through the middle pipe
- When this mixture is cooled, the solid sulfur separates from water and 99.5% pure sulfur is obtained
Is this basically the process? Also, are these the properties of sulfur that this process relies on:
- Sulfur has a low density, hence the compressed air is able to lift the sulfur-water emulsion to the surface
- Sulfur is insoluble in water and not reactive. Hence, sulfur can be recovered more easily after the sulfur-water emulsion cools as it does not mix with the water, nor react with it.
There are also some problems with this process if I am right:
- The hot water used in this process causes thermal pollution, and may also contain some dissolved minerals. This may disrupt the chemical composition of local ecosystems, so one must recycle it.
- Depending on the make up of the area, remaining crypts can lead to earth subsidence. These are also harder to refill.
- This process releases sulfur, which must be quickly cooled otherwise it oxidises to sulfur dioxide or may be reduced to hydrogen sulfide, both of which are serious air pollutants.