Arizona silver belt., 1888-10-20
Economical Mining and Milling.
IN. Y. Engineering and Mining Journal.

1t IS important Tor pfeSpsctors anu investors Tn inning properties to bear in mnd that by improved machinery and methods of working, as well as by increased freight facilities, tho cost of production has been so greatly re- ducsd that low-grade ores which would not have been thought worthy of attention ten years ago, can now be treated at profit, the result of ey- perienee and close attention to econ omy. Indeed, itis to these causes and agencies at work quite as much as to new strikes that we must look for the growth of our output of the precious metals.
 Ali of our readers are familiar with the wonderfully economical treatment of the Lake Superior copper ores, ey which ton of orc is stamped and sep arated at a cost of 2 cents per ton. Also many will remember the figures we gave in full detail in our issue of May 9th of this year with reference to the low cost of mining and milling in the Spamsh gold mine. Nevada conn ty, California, where the cost of min ing averaged in six months 34 cents per ton, and the milling and amalga- ting iu Huntington mills amounted to only g cents per ton, thus showing that with large body of free milling are, yielding even much less than Sl ton fair profit to the investor may be obtained. We also know officially that al ths Treadwell mne ol the Alaska Mine and Milling Company the cost of mining and milling was under Sl 9 per ton. This when the compa ny was running 20 stamps, and now that they have 2l0 running It is pos sjble that the cost is reduced even ba- low this figure.
 Silver milling and amalgamation is always looked upon, and properly so, as much more costly than free gold treatment; but to show what can be accomplished in this also we give the following particulars of two eases which have come unde, our notice: 1t the Gloster mine, Montana, where supplies are dear, with 60 stamps of $50 pooudS, there were milled and amaigamated by the Boss continuous process in SIX menths 26,20l tons of arc, a cost of $l99 psr ton, There were l69 days working time, giving an average of IA tons per 24 hours, and the expenditures were as follows: Quicksilser, Sl955; weed S8274 salt, $3222; shoes and dies, s6460, the bal. ance being .sde up of lahsr and man ageinent. Subsequently, la one month at the ss,ns null the average uumber of tons pm: through amounted to l9l tons ln 24 ben;s, and the cost was re- dueed to Sl 20 per ton. Considering ths price of labor, the cost of mining was low also, amounting 10 S336 for the six months referred 10, including all expenses. This shows that free milling silver ore eau be mined, nilled, and amalgamated for $456, a result that reflects great credit on the man. ageaent
 Tie other instance that we shall qUets in support of what can be done ii the St. Helena mine in Sonora, Mexico, where 4320 tons were mi.isd and amalgamated at au average cos. of & 72 in Mexican money, or about $l 9G-n u'55iSlrsuStates currency What makes this ease more striking is the fact that more than ene.tbird of the cost was thefuel which was poor wood at S3 per cord, We have not before us the cost of mining in this case; but te show that tue cost of tue treatment of 1920 tons was not exceptional, the figures of the whole years operations slowed q cost of about S2.30 in Amer ican currency for milling, amalgama- tlon and superlntendence.