Bisbee daily review., 1917-01-28

carried more or less sulphur, and as a result our bars not only fell of in percentage, but were appreciated in quality and we made an increasing quantity of matte.
 Reduction Methods
 This was re-nOyed partially, as il chilled on top of the copper bare, was roasted in stalls and returned to the supOlas. But il became imperative to abandon the conyertion of our oxidized copper ores into metal directly by a single fusion and to matte our mixed oXIdes and sulphides. The decision was reached in 1892 and l went to Eu- rope to investigate the Manhes- -Besse- mer process, and a peculiar form of barrel converter, which was preferred there to the upright converter hereto fore used in Butte. and which had been introduced there by N. Mahnes' representative, Mir Franklin Farrell. At M. Mahnes' suggestion my son ana l visited the works of the Metallurgi- cal Society in LeShorn, where a very
 
 small type of barrel converter was in operation worked under very low blast and handled without electric cranes. On my return Fraser and Chalmers designed for us a converter of a larger size, but of the barrel type and three of those were installed with Riedler blowing engine and started in the aut- umn of 1894. The blowing engine was built to give a pressure. if necessary, of thirty pounds. should We be obliged to revert to the deep, upright convert CT, but in practice il was found that a pressure of eight to twelve pounds was sufficient.
 Refining Expensive
 "The 36-inch furnaces had mean while been displaced by furnaces oI 120X42 inches. In the first Bessemer plant each converter of an estimated capacity of one million pounds of cop per a month was coupled up with the we'll Of cupola, which was expecte- to smelt approximately the quantit, of ore into matte, which the converter harnessed to it would reduce. But after some years of practice the losi of time occasioned by the converter waiting for the furnace, or the furnace for the converter, induced us to intro duce an electric crane. whereby the matte from the we'll of the four flu: naces could be converted to any on of the four cOnverters. The silver in our ores is not uniformly distribute and the cost of electrolytic refinin was heavier than 1t is now, and there l fore at first we assigned one couple | furnace and converter to selected COT | per-silver ores; but as the rednin charges were lowered We found it pro ftable to refine all our copper electro iytically to receive the higher pric which electrolytic copper commands over casting, and the Sl0 to SIP of precious metals which each ton of bull lion from Queen ore carries.
 When the Queen was opened the application of the pneumatic method to the metallurgy affected. and to re- duce sulphide ores by the old methods with the high cost Of labor and fuel would have been unprofitable. But when in the Bessemer converter the liquid matte from the cUpola could be blown up into copper of 90 per cent instead of the old black copper stand ard of 96 per cent. the increased cost of reduction was insignificant and cv- en this was compensated for many fold over by the saving of copper in the slass In 1894 the furnace yield of our ore was 757 per cent. but in 1891. the first year of the Bessemcr method it rose to S.39 per cent the difference being entirely in the reduc- ed slag loss. We now know from act ual treatment of the old slags made before the introduction of the convert CT that they yield % per cent Those of the Clifton and Globe districts yield even higher. which accounts tor the ill success oi minin- In those camps