Arizona republican., 1915-05-02

roasting operation.
 l regret that am only slightl.
 familiar with the very importan
 work in the development of a process
 by E. A. Cappelen Smith for tn
 beneficiating of the Chquicamat;
 ores.
 Recovery of Copper From Solutio,
 At the beginning of our inVestigs
 tion we seriously considered wha called the brutal method O.
 teaching, namely, the manufacture O
 sulphuric acid. the solution of the
 copper from the ore with such acid and the precipitation of the coppe:
 by metallic iron, with the resultan complete, or nearly complete, de l struction of both acid and iron an( the production of an impure cement copper that would have to go throuGh h the process of smelling and refining | The results of Croasdale's tests and 1 Wedges cost figures indicated thd( 1 such a course was commercial, and We concluded that the 115 per cent l Ajo ore, with no oVerburden, mined 1 by steam shovel and crushed coarse
 would yield a profit on a 12-ct. cop Der market if a cheap grade of Ala i hama pig irCn were used
 | But it occurred to me, as it had l occurred to many engineers, that 1 oxide of iron could be reduced to
 metallic iron without fusion, and if
 so We might bring Bisbee sulphides to the mines, calcine them for the | manufacturer of sulphuric acid and then metallize the available iron In the impure calcine. already contain ing values requiring recovery, and use this for precipitant. l found at the start that metallic iron was being produced by this method with
 an inferior fuel from high grade iron
 ore by an intermittent process; that
 is, by first heating to the desired
 temperature by internal combustion
 of a part of the excess coal in the
 charge and then allowing the heated
 charge to stand without the admis-
 sion of air, but allowing the gases
 formed to freely escape
 We concluded to try the experiment of a multihearth furnace, and ar first my idea was that possibly cal
 ching could be done on the copper hearths and the hot calcIne could then pass to the lower hearths, where
 it could be further heated and sub mitted to reducing action. We erected a small Wedge furnace. but only tried to metallize. and not to calcine in it. Some of the iron oxide Was reduced to metallic iron, but on the whole our experiment was :. failure because in keeping the charge hot the percentage of carbonic acid gas produced was sufficient to re- tard and reverse the action of car bon monOXide in reduction. In par allel with this. we also made expert ments in revolving cylinders. aiming to reduce the iron to the metallic form with illuminating gas and with fuel oil by continuous process These also were failures
 MT. Laist conducted similar experi- ments on a continuous process for | making sponge iron at Anaconda. | and ended with q like failure He | has, however. demonstrated that he | can make sponge iron by an inter | mittent process in a revolving drum. | It had become evident to me that | the simple use of iron, with the des- | of both iron and acid. to | he production of an unfinished pro- 1 luct, while apparently commercial. "as in our extremely simple case and investigation show ad the splendid work done on other lines and convinced me that if con sldered from a commercial viewpoint better methods Were bound to de- Velop a process that would fit our requirements, and very much cheaper copper would result
 At the stat we decided 70 inves- lgate tho clec:rolytic depositicn f z pper rom solution, but q lttle arer on, we took up the subject of
 l" Glrect precipitation of tl.e cop 'er oY sulphurous acid gas. : prefer " attt~k tie latter subject sirs. for he purpose of this paper
 In the precipitation of copper bv irlphurous lcid gas, temperltura anG consequent pressure must be cous,d- rcd. If the copper is precipitatcl in metallic form this tempera ture and pressure are very high but f T sub 'hlori0e of copper would satisfy. tre cmperature and pressure may he moderate. IT, both of these processes, he reactions we are familiar wl-'i in he format on of sulphurous ac'd hr |. rcatinS copper tailings with concen- rGted sulpf uric acid are reversed y heat. For the production of me allie copper the action depends upon setting sulphurous acid dissolved in he sulphate solution in sufficient , mount to precipitate the copper and hen heating the mixture under pro- 'er control of about 150 degrees C. The question of the use of an ab- rich gas is involved. Un- Ter proper regulation pure copper is 'roduced, which only needs melting CT the market and a large excess if sulphuric acid is formed Van Arsdale has done valuable original york on this process, followed by the york of Weidlein and others in it's commercial development Laist has tudied precipitating sub-chloride of Cpper. soluble chloride is added 0 the sufphate solution of copper nd the proper amount of sulphurous cid is added. Moderate heat under ressure-90 degree c. of heat-pre- ipitated almost all the copper as ubchloride. The subsequent process } f obtaining the copper without vo- ! utilization and the recovery of the {