SULPHUR AND ITS EXTRACTION. 



493 



but merely change it from a solid to a liquid state by the action of 

 their heat, carbon bisulphide actually dissolves the sulphur and re- 

 deposits it by evaporation. The plant necessary for carrying out this 

 process is shown in Fig. 5. It is designed of dimensions suitable for 

 dealing with twenty tons of raw sulphur mineral per diem, yielding 

 fifty per cent of pure sulphur. The four extracting pans, a, h, c, d, 

 have each a capacity of five tons, and are made of three-eighth inch 



r\ 



Fig. 5. 



wrought-iron plate ; they measure six feet long, four feet wide, and 

 four feet deep internally ; and are fitted with a perforated bottom dia- 

 phragm, with connecting pipes, m, leading to the underground solu- 

 tion-tank, f, with another set of pipes, Jc, for admitting steam from the 

 boiler, i, and with a third set of pipes, I, communicating with the 

 store-tank, g. The still, e, is a steam-jacketed " wrought- jacket " pan, 

 six feet long, four feet wide, and four feet deep, with cast-iron ("loam 

 casting ") oval-shaped bottom and ends, one-half inch thick, and pro- 



