Arizona republican., 1915-05-02

JollierS in the state of Arizona
 For several years he has covered the
 state. installing hot air and electrical
 plants in many of the largest county
 buildings and school houses in the istate
 and Hahn plant was installed and l the use of sulphurous acid was tenn porarily discontinued. As for the GreenWay process. l am not yet at
 liberty to discuss it further. But I l may say over 100 charges were run ! with this process. The iron content | in the solution was kept down to less than 1 per cent, and we obtained an l average of slightly over l pound of copper per kiloWatt hour, but the ex- | traction was low. We then extended 1 the time of the leach and obtained l a higher extraction, and finally we | began to crush the ore, which at that
 time had been crushed only to 1-2- 1 inch ring, finer, and found that if I crushed to pass 1-4-inch mesh per l collation. was not retarded and an | extraction of over so per cent was l practicable. The iron has reached
 as high as 12 per cent. but we are still getting a pound of copper per 1 kilowatt hour from the electrolytic | tanks.
 1 These experiments have been so 1 successful that we are proceeding with the erection of a 40-ton plant, | where tanks will be used that will | hold 60 tons, if necessary. and will ] be abundantly large to permit of a study of the comparatively even dis | tribution of crushed ore. and we shall proceed with these most interesting experiments. using first. as, we have l in the smaller tanks, the Greenway process. In the meantime the 1-ton l plant will be liberated and We will | immediately proceed with the con | tinuance of a modified form of the Antisell system of teaching. He finds 1 that with the construction of better absorption towers we can absorb the l necessary amount of SOP gas. and | he has demonstrated that with the I use of SO2 gas, using dyad iron as a depOlarizer and triad iron as an OXidizer. he can manufacture sulphuric acid. We can, if successful. obtain 1 1-2 pounds and possibly more, of copper per kilowatt- -hour. and at the same time manufacture sufficient acid to replace wastage. The cleo | trolytic copper in all cases has been fHlly up to the trade standards. Conclusions
 My deductions from a study of the work of the able engineers engaged in these extensive operations are as follows:
 1. Dilute sulphuric acid will give a very high extraction on oXidized ores of the Ajo type. Time is more inn portant element in extraction than strength of acid. A maximum size of q crushed to the maximum size permits
 percolation and the production of a
 clear solution because the slime con tent in the ore so crushed is very
 small.
 2 Where such ore is mined at d
 cost of between p and 90 cents a
 ton, it is commercial on a 12-ct. mar
 gin. even if Ieached with sulphuric acid and the copper precipitated with
 pig iron to the waste of the acid and
 iron and the production of an inn
 pure cement copper that requires
 further treatment. Metallized iron from calcines can be made and will prove a little cheaper than pig iron if it is marginal.
 3. An electrOlytic method for the recovery of pure copper from suIphate solutions is far preferable and will produce cheap copper. In all cases a low current density is required. Hard lead anodes or composite anodes of hard lead and coke of uniform thick ness will be used.
 4 Such electrolytic method. with control of the amount of iron and aluminium in the electrolyte, and without the use of sulphurous acid gas, is practicable. An acid loss of about 1.5 pounds per pound of copper will be sustained. Chamber acid will be required.
 ,. I believe there is a decided prob | ability that the cheapest and best method will be the electrolytic deposit tion from sulphate solutions without 1 iron control. and the use of the re- quisite quantity of sulphurous acid. | The sulphurous acid will be absorbed | withot the tank house and in quan l tity that will not cause annoyance. | Iron and aluminium will act both as | depolarizers and catalytes. This pro- | cess promises a high yield of cathode | copper per unit of power and the l manufacture of sufficient sulphuric | acid to replace the waste.
 G. While these remarks apply to the | Ajo oXidized ore and ores physically | and chemically similar. they need not | apply to ores of different compost l ton. Mixed oxide and sulphide ores. | be the suIphide chalcocite or chalco- prite and bornte; ores containing great quantities of clay, or presenting ! other difficulties, have to be consid- | cred separately, and there is beyond question a great field for other pro- cesses and for other methods, both for obtaining the copper in colution and obtaining the copper from the solution.
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