660 ANNUAL KEPOET SMITHSONIAN INSTITUTION, 1913. 



prominently to public attention through experiments on a fairly 

 large scale noAV being conducted in the western smelters, both on the 

 " Thiogen process," ^ developed by Prof. S. TV. Young, of Stanford 

 University, and the " Hall process," ^ due to W. A. Hall. The out- 

 come of the practical installations and tests under way are being 

 awaited with much interest. 



Even if these methods prove successful at some particular plants, 

 we must not jump at the conclusion that the smelter-fume problem 

 in general is forthwith solved, for except where a read}^ market can 

 be found for the sulphur produced, the extra cost of the oil or other 

 fuel required would be a serious consideration. By far the greater 

 part of the world's production of sulphur goes at present into sul- 

 phuric-acid manufacture, so it is evident this brings us back once 

 more to the question of a market for that substance or the discovery 

 of new uses for sulphur itself. Since sulphur, however, weighs onlj'^ 

 one-third as much as the sulphuric acid which can be made from it 

 and is an inert solid instead of a corrosive liquid, the conversion of 

 the gas to this form at the smelter may aid in the transportation 

 problem even if it is reburned and manufactured into sulphuric acid 

 at its destination. 



There is also the chance of so modifying present smelting practice 

 itself that, wdth the expenditure of little or no extra fuel, part of the 

 sulphur now being burnt up in the furnaces would be distilled off 

 and collected in the unburnt form. Some of the modern develop- 

 ments in smelting practice during the last few years seem to point 

 strongly in this direction, although here again the possible improve- 

 ments are probabl}^ limited to certain branches or departments only 

 of the Avork, and part of the sulphur would have still to be taken care 

 of by such other methods as already mentioned. 



To sum up : The smelter- fume problem as a whole is really made up 

 of so many distinct elements, including character and quantity of 

 ore and fuel supply, processes employed, location of works, transpor- 

 tation facilities, available markets for products, etc., that we can not 

 expect to find any one general solution of the difficulty; but it is 

 encouraging to observe from how many different standpoints the 

 question is being seriously attacked by practical men, and from the 

 sum total of the different improvements applied, and diverse outlets 

 for by-products being found, we may with fair confidence look to 

 steady if not rapid improvement in the general situation. 



1 The Thiogen Process for Reduction oi SO2 in Smelter Fume, by S. W. Young, Mining 

 and Scientific Press, vol. lO.*}, 3S6-3S7, Sept. 23, 1911 ; Thiogen Process Demonstration 

 (Illustrated), by L. n. Eddy, Engineering and Mhiing .Tournal, %'ol. 93, 873-874. May 4, 

 1912. See also Vogel in Rauch and Staub, 1. c. 



- The Hall Ore Desulphurizing Process, by W. A. Hall, Engineering and Mining Journal, 

 vol. 96, 35-36, July 5, 1913. See also Editorial comment and abstracts of patents, The 

 Mining Magazine, vol. 9, pp. 92-93, Aug.. 1913, and vol. 10, pp. 141-142. Feb.. 1914; also 

 inr: rvitisb Patents to W. A. Hall 207r)7. 20759, 20760, 26595. 



