Mecovery of Copper from its Solution in Mine Drainage, oil 



At Herrengrund (Hungary) the waters are run through in- 

 clined troughs, the bottoms of which are stepped and covered 

 with irons. 



At Schmollnitz the waters are conducted through precipitating 

 vessels twelve teet long, twelve inches broad, and ten inches deep 

 connected with each other, and arranged in terraces, in which the 

 pieces of cast-iron are piled in lattice fashion; when most of the cop- 

 per has been precipitated the solution becomes muddy and deposits 

 basic salts. It is then conducted by a gutter into vertical vessels 

 furnished with iron plates, and the precipitation of the remaining 

 copper is thus facilitated by the impact of the solution upon the 

 precipitating iron. The iron plates are cleaned daily, and the 

 cement copper is removed every fortnight from the first vessels, 

 and every four weeks from the lowest. Of other localities whei'e 

 mine drainage is treated, may be mentioned Falun (Sweden), 

 Rammelsberg (Hartz), and Agordo (Venetian Alps). The method 

 for treating poor ores at the latter place will be noticed further 

 on. (Page 320). 



tanks ; each some sixty feet long, sixteen feet in width, and three feet in depth, where it 

 is lixiviated by successive additions of water, which, after dissolving out the salts of copper, 

 is run through an extensive labyrinth of tanks, in which pig-iron is regularly stacked in 

 hollow piles." Here the iron is dissolved, and " the copper in a metallic granular state, 

 but contaminated with the carbon and other impurities of the pig-iron, is dejiosited. In 

 order to collect this precipitated copper the liquurs are diverted in succession from the 

 various tanks, forming portions of the arrangement for precipitation, the liquids drawn 

 off and the iron removed from one end of the tank, and adhering copper being brushed 

 off. The copper in the bottom of the tank is now collected, and the cleaned iron replaced 

 with an addition of fresh pig, the operation being continued with the next stack in suc- 

 cession, until the whole of the pig-iron has been cleaned and freshly stacked, and nearly 

 the whole of the copper taken out. This precipitated copper when washed, freed from 

 fragments of iron, and calcined, contains about 75 per cent, of metallic copper. It is 

 then bagged and forwarded to England to be refined and melted into ingots, as the high 

 price of fuel in Spain renders it inexpedient to complete its metallurgical treatment in 

 that country." — J. A. Phillips, f.g.s. Popular Science Heview (1879), Vol. XVIII., 

 page 113. Only about 50 per cent, of the copper present in the ore is saved by this 

 process. 



