Weekly Arizona journal-miner., 1905-05-24
THE NEED OF CAREFUL INvESTI
 CATION.

] nc frequency Nlth NHich htStdhto arc made in the premature installations of mining and metallurgical plants, par tieularly of the latter, is a matter of constant surprise in the light of the experience which this age affords. This is emphasized by the thorough test ing of small amounts of ore, which is necessary if we are to determine it's character and the proper method of it's benefciation. Then the construction of unit plant of full size, complete in detail. and the demonstration, on commercial scale, of the process evolv- ed by the laboratory experiment can follow.
 The wisdom of this advice cannot be doubted. as is too often shown in idle mills and reduction works built at great cost. but wholly unsuited to the treatment of the ore of the mine for which they were built. Formerly, when metallurgy was not in so advanced a stage as at present, there could usually be found an excuse for such prema- ture installations, but not so in these days, and yet, these occurrences, by courtesy called mistakes, are not infre- quent. Over twenty years ago an east ern company operating in the Black Hills of South Dakota, expended many thousands of dollars in an attempt to work the rebellious telluride ores of the Bald Mountain district. A e0- stamp mill was built, and it was un- able to give capacity, and at the same time crush the ore fine enough, and the stamps were taken out, the mill re- modelled and half a dozen Pulverizers of popular type in those days, were installed. These proved of little use, and were in turn rejected, and the twenty stamps replaced. These were then supplemented with six large grin | ing pans, similar to the pans in sill yer mills. These required largely increased power, which was provided. Still ,the ore was refractory to every method tried. chiefly various kinds of amalgsmatiOn. Colonization was suggested but rejected as too expen- sive. The stamps were again torn out and a new type of pulverizer-rolls was tried This was no more success | ful than the other devices, and the company, at last discouraged, gave up the effort and waited for science to seek out a method in the coming years. These repeated endeavors to treat re- | fractorv ores were certainly deserving of greater success than attended these efforts. The only regret which the company could entertain should be elaborate scale, for in each instance a mill was built that should have been capable of treating at least fifty tons daily. when the same knowledge might have been gained with a one-stamp battery or a single pulverizer. These are now successfully treated by cyanidation, for they arc no more amenable to amalgamation today than they were at that time. Even today may be seen in similar honest efforts wasted in the endeavor to work out a metallurgical process which will sue eessfully treat a refractory ore, appear ing in the shape of large, fully equip ped plant, when it is not known that the process and the machinery are ad- apted to the ore. Make the small tests first, and when the laboratory experiments have demonstrated the probable adoption of certain line of
 treatment to the ore, it will be time enough to build a full-sized unit plant to prove that the intended process will
 do what the experimenter thinks it
 will. Having demonstrated this fact
 it will then be the proper time to : put in a plant of a size and capacity
 commensurate with the possibilities of
 the mine to supply ore continuously
 Mining and Scientific Press.