What is the name of the process of extracting sulfur on commercial scale?

Frasch process

The correct answer is: 4. Frasch process.

The Frasch process is a method used for the extraction of sulfur from underground deposits in a way that is both efficient and environmentally friendly. It was developed by Herman Frasch in the late 19th century and has been a key process in sulfur production.

Here's a detailed explanation of the Frasch process:

1. Identification of Sulfur Deposits:

The process begins with the identification of underground sulfur deposits. These deposits are typically found in salt domes or cap rocks.

2. Drilling Wells:

Wells are drilled into the sulfur deposits, usually reaching depths of several hundred meters. These wells are designed to access the sulfur-containing layers underground.

3. Injection of Superheated Water and Air:

Once the wells are in place, a mixture of superheated water, steam, and air (or sometimes nitrogen) is injected into the sulfur deposit.

The superheated water and steam melt the sulfur underground, forming a mixture of molten sulfur and hot water.

4. Extraction of Molten Sulfur:

The molten sulfur is lighter than the surrounding materials, so it rises to the top of the sulfur deposit.

5. Pumping to the Surface:

The molten sulfur is then pumped to the surface using the pressure of the injected fluids.

The pressure of the injected fluids also helps to prevent the entry of water or impurities into the well.

6. Collection and Solidification:

Once at the surface, the molten sulfur is collected and allowed to cool and solidify.

The sulfur can then be further processed and purified as needed for various industrial applications.

The Frasch process is advantageous because it allows the extraction of high-purity sulfur without the environmental issues associated with traditional mining methods. It's especially useful for sulfur deposits that are deep underground or located in environmentally sensitive areas.