356 JOSEPH STRUTHERS 



York, and Ohio. The mineral was mined in these states in 

 1902. Virginia supplied nearly one half of the total. The 

 production in Indiana and Ohio was in the form known as 

 coal brasses, obtained as a by-product in the mining of coal. 

 The total quantity so produced, however, was but a small pro- 

 portion of the total output of the United States. It is not prob- 

 able that the production of pyrite from this source will ever 

 become of importance. 



There are many other deposits of pyrite in the United 

 States, but they have not been exploited because of the impure 

 or low grade quality of the ore and the excessive cost of mining 

 and of transportation both to and on the railroads leading to 

 the centers of consumption. Some of the ores not now deemed 

 of sufficient value to be worked for their sulphur content will 

 eventually be profitably treated by modern methods. In the 

 southern states particularly are many deposits of this character, 

 which could produce enormous amounts of sulphuric acid in 

 this manner at prices lower than the present average prices at 

 the seaboard. A condition which has served to retard the 

 growth of the production of the domestic ore lies in the fact 

 that foreign ores can be imported and accumulated at the sea- 

 board and shipped inland in quantities sufficiently large .to 

 secure very low freight rates. 



A promising prospect for the pyrrhotite ores of the south 

 lies in the feasibility of their utifization for the manufacture of 

 sulphuric acid. It is claimed that the sulphur contained in 

 these ores can be so effectually removed that the residual pro- 

 duct will be of value in the manufacture of pig iron or even of 

 steel. For this purpose the cinders or residues from the roast- 

 ing of pyrite for the manufacture of sulphuric acid have been 

 utilized to advantage. It is well known that the residues from 

 Spanish ores treated by the Henderson process have been sold 

 either in the form of fines or briquetting and utifized in 

 the manufacture of steel, but in the United States roasted 

 pyrite residues have not yet been utifized for the manufacture 

 of iron on account of the large percentage of sulphur remaining 

 in them after treatment in the chemical works. If pyrite 

 residues could be roasted so that the amount of sulphur re- 

 maining after treatment would be so small as to permit of their 



