An igneous method discovered by an American engineer Herman Frasch. He has been adopted to extract sulphur from underground. The basic principle of this method is that sulphur is method underground and pumped up to the surface.
To extract sulphur, a hole about 30cm in diameter is bored down to the deposits of sulphur. A sulphur pump made up of three concentric steel pipes is then driven down the hole. The outer most pipe (20cm diameter) is sunk up to the deposits and the next inner (10cm diameter) is held a little above the surface of deposits. Super heated water at 170°c under a pressure of 10atm is forced through the outer most pipe to the sulphur bed to melt the sulphur.
Hot compressed air at a pressure of 15atm. Is then blown down through the inner most pipe (5cm diameter) to force the molten sulphur up through the middle pipe. It forms foam of molten sulphur which arises through the space between the inner most and the next pipes. When this form of sulphur reaches the surface it is collected in big wooden basins. After some time air and water escape and the sulphur is solidified in huge blocks at the bottom of the tank. Sulphur obtained by this process is 99.5% pure.
To extract sulphur, a hole about 30cm in diameter is bored down to the deposits of sulphur. A sulphur pump made up of three concentric steel pipes is then driven down the hole. The outer most pipe (20cm diameter) is sunk up to the deposits and the next inner (10cm diameter) is held a little above the surface of deposits. Super heated water at 170°c under a pressure of 10atm is forced through the outer most pipe to the sulphur bed to melt the sulphur.
Hot compressed air at a pressure of 15atm. Is then blown down through the inner most pipe (5cm diameter) to force the molten sulphur up through the middle pipe. It forms foam of molten sulphur which arises through the space between the inner most and the next pipes. When this form of sulphur reaches the surface it is collected in big wooden basins. After some time air and water escape and the sulphur is solidified in huge blocks at the bottom of the tank. Sulphur obtained by this process is 99.5% pure.