COLLECTIONS IN ECONOMIC GE(31,()GY AND METALLURGY. 97 



ami tossiug the hetuls from the last tablo in a kt3eve. (Ira(l(3 No. 4 B, containing 

 al)ont 33 per cent, of copper. (54710.) 



(15) Copper, obtained from the black sands of th(; last row of finishing sieves, by 

 treating theai on the head buddle and tossing in a keeve. Grade No. 4 C, containing 

 abont 32 per cent, of copper. (54711.) 



(10) Final tails, as discharged into the lake. (54716.) 



SMKLTIXO LAKE SUPElilOIt COrPEIi. 



The product of all the Lake yuperior mines consists, according to 

 sizes, of: 



First. Mass copper cut from the hirge masses, being nearly pure cop- 

 per. 



Second. Mass copper ctwitaining considerable adhering rock matter, 

 sometimes called kiln (;o[)per, because it has been treated in a kiln to 

 remov'eas much as possible of the rock matter. 



Third. Barrel copper; small masses broken from the rock and yet 

 containing some adhering rock matter. 



Fourth. Stamped co[)per of various grades, the coarsest being nearly 

 pure copper, while the finer grades contain increasing amounts of rock 

 matter, especially magnetite, and also particles of metallic iron from 

 the stamps. 



All this material has to be melted in specially constructed reverber- 

 atory furnaces and then refined to remove the iron. 



C. G. HUSSEY COPPER WORKS, PITTSBURG, PENNSYLVANIA. 



These works treat entirely the products of the Mass Mine, Lake Su- 

 perior, 10,000 pounds are charged into a reverberatory furnace in the 

 afternoon, a suitable mixture being made of the small masses or kiln 

 copi)er and the stamped material. The charge gradually melts, and 

 at 6 o'clock the next morning the process of refining begins. The 

 melted metal is first oxidized to remove impurities and then poled with 

 green wood to get "tough pitch" metal. This is generally finished 

 about 10 o'clock, when casting begins. The refined coj^per is cast 

 into long bars for rod rolling or into slabs for sheet rolling, and the 

 entire product is consumed in the same works. The specimens include: 



Ore. 



(1) A small mass, representing the barrel and kiln copp<'-r. (54072.) 

 (■2) Stamped cop[ter, a mixture of several grades of stamped material. (54973.) 

 (3) Stamped copper, the finest grade from the treatment of the slimes and tail- 

 ings. (54974.) 



Fud. 



(1) Mituminons coal. (55209.) 



(2) Charcoal, nsed in the refining as a reducing agent. (54985.) 



J iitenncdiiite products. 



(1) Copper, taken from the bath before, bcgiiiniiig to rabble. (54975.) 



(2) Slag, lirst .skimming. (.54980.) 



(3) Copper, taken from the bath after rablding. (54976.) 



9110— No. 42—^7 



