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THE MINING AND QUARRY INDUSTRY 89 



belonging to the Port Henry company, with the Bonanza and Joker 

 of Witherbee, Sherman & Co., are on a single ore body which for 

 some time has supplied the greater part of the output from the dis- 

 trict. There are reserves sufficient to last for many years. The 

 continuation of the ore body in depth beyond the present workings 

 has been proved by diamond drilling. Developments in the Joker 

 mine during the past year have also enlarged its limits along the 

 line of strike. At the south end of this mine the deposit is cut off 

 by a diabase dike which it was thought might mark a line of fault- 

 ing; drill holes driven through the dike have found ore for indefi- 

 nite distances, so that little, if any displacement seems to have 

 occurred. 



The Harmony mine lying south of the Joker shaft was opened 

 quite recently by Witherbee, Sherman & Co. and is still under 

 development, though supplying important quantities of ore. It 

 is equipped with two large shafts. The Smith mine belonging to 

 the same company is located some distance north of the Old Bed 

 group. It was inoperative for several years and is now being 

 reopened. 



The Mineville ores are varied in character. Those from the Old 

 Bed are the richest in iron and carry the largest amount of phos- 

 phorus. They are particularly adapted for making basic iron, owing 

 to their low silica content combined with high phosphorus. The 

 latter usually exceeds i per cent, but can be reduced nearly one 

 half by concentration. They are also extensively employed as a 

 basis for mixtures with other ores in making foundry irons. The 

 Harmony mine yields an ore containing less phosphorus, though not 

 within the Bessemer limit. The New Bed and Barton Hill work- 

 ings, which are now closed down, have supplied excellent Bessemer 

 ores. 



Both companies have well equipped surface plants for handling 

 the mine output. The installation of Witherbee, Sherman & Co. is 

 specially extensive and includes two large mills for crushing and 

 concentrating the ore from their different mines. Concentration 

 is effected by magnetic separators of the Ball & Norton drum and 

 endless belt types. 



In treating the Old Bed ore the iron content is raised from about 

 60 per cent to over 65 per cent and the phosphorus lowered to .5 or 

 .6 per cent. The tailings from these separators are retreated by 

 Wetherill machines which make a further concentrate of mag- 

 netite and a tailings product carrying 12 per cent phosphorus, or 



