The copper era., 1909-08-26

After a certain time the solution will be found to contain copper huosili- cate and lead iuosilicate, and when sufficient metals have become dissolyep in this manner, the electrodes are disconnected and the solution drawn off into storage tanks for further the electric current used in this re action is the result of galvanic action and is primary or internal current and not current obtained from out end of this operation the reduction tank is again charged with fresh ore, and covered with solution ready for repeating the operation "-'.
 Operation "C". The sulphuretted hydrogen, arsene and stibine, carried over the Operation "A" and stored in the storage tank, are treated in the following manner in order to recover the sulphur, arsenic and antimony.
 A suitable burner is provided, through which the above mentioned gases are forced and are burned with the proper amount of air to form sul- phur dioxide, arsenic oxide and anti mony oxide.
 The sulphur dioxide passes of as a gas and may be collected and used to manufacture sulphuric acid. The arsenic oxide and antimony oxide are precipated as white powder.
 Operation "D". The electrolyte carrying the salts of copper and lead received from the reduction tank in Operation "B" is caused to flow through the electrolytic precipitat- ing tanks in which are suspended car bon anodes and overflows through the pipe and into the next tank. In pass ing through the electrolytic tanks, the electric current causes the pre- cipitation or deposition of the cop per in the solution upon the copper cathodes in solid, refined condition; and at the same time the lead con- tained in the solution is precipitated or deposited upon the anode in the form ot lead peroxide, which forms a hard, dense coating upon the surface of the carbon anodes, thereby protect ing them from oxidation or dissolving in the solution.
 Where the ore contains sufficient lead to increase the coating of per oxide above a certain thickness, it may be stripped of and melted into pig lead ready for the market, the carbon taking on at once new coat ing of lead peroxide from the solu- tion.
 When the copper cathodes have at tained a thickness of It to ? inches they are removed and a new thin plate is put in its place to build upon. The copper produced by this method is refined electrolytic copper and is ready for the market without further treatment.
 The thin copper cathodes, or start ing plates, may be made by first coat ing copper plate with graphite and oil and allowing copper to deposit upon it until it is about one-eighth of an inch thick, at which time the new plate is easily separated from the old one, the new plate being used to build upon in the usual manner.
 As pointed out before, the electrode surface is increased in each tank as the per cent of copper in the solution decreases, resulting in solid deposit of copper, and high per cent of ex- traction.
 The solution after passing out of the last tank has very little copper or lead left in it and is in condition to use over again and may be used indefinitely. The carbonates and OK. ides of copper and lead will readily dissolve in the acid solution, with out operation "A", the solution being treated as above.
 A small model showing the opera tion of this process is now on exhibit at the office of the Pan-American Ore Reduction Company, 536 s. Spring street, Los Angeles, Cal.-Los An geles Mining Review.