354 JOSEPH STRUTHERS 



able on account of the cost of fuel in those regions where sul- 

 phur occurs. Sulphur may be extracted from the ore by a sol- 

 vent, such as carbon disulphide, which may be recovered after- 

 wards, but this method necessitates an expensive plant. For 

 some ores a treatment with a solution boiling above the melt- 

 ing point of sulphur has proved successful. The ore is placed 

 in an iron basket or crate in a boiling solution of calcium chlo- 

 ride, which boils at 125° C. The sulphur melts and flows away 

 from the matrix of stones, etc. ; passing through the meshes of 

 the basket and falling to the bottom of the tank, it is drawn 

 off and cast in molds. After it is melted out, the basket of hot 

 stones is lowered into a tank of water, which is heated by the 

 stones, while it removes the adhering calcium chloride from 

 them. This warm water is then used to replace that lost from 

 the boiling calcium chloride solution. This process causes 

 noloss of sulphur as sulphur dioxide, and no nuisance is 

 created, while a fairly pure product is obtained. The calcium 

 chloride used is a waste product of the ammonia soda indus- 

 try. 



In the United States, the extraction of sulphur by means 

 of superheated steam has been tried, and an excellent quality 

 of sulphur has been obtained without formation of any sul- 

 phur dioxide. The cost of fuel in the west, however, is an ob- 

 stacle to the further development of this method. In Lou- 

 isiana, as mentioned earher in this paper, steam is forced under 

 pressure, through driven wells or tubes, into the sulphur de- 

 posit, which partly refines the sulphur, liquefied by the heat. 

 The molten product is forced to the surface by the steam pres- 

 sure through a small pipe inside of the steam pipe. Generally 

 the method of extracting the sulphur from the ore, and at the 

 same time of partially refining it, is to treat the ore in a cylin- 

 dical or slightly conical cast iron vessel of a capacity of about 

 5 tons of ore. Steam inlets are provided at the top and bottomx, 

 also a bottom valve through which the melted sulphur is with- 

 drawn and cast into molds. The size and the form of this re- 

 fining vessel depends to some extent upon the nature of the 

 material to be treated. If the ore is porous, a higher vessel of 

 greater capacity can be used, and with ores that increase their 



