Bisbee daily review., 1916-05-07
IMPROVED MINING IS
 AID TO CONSERVATISM
Continued From Page One.)

as improved and developed by Mir Me Donald at Inspiration. Through these I efforts ths unit cost of mining has been tremendously decreased and we have been enabled to mine exceeding ly low-grade material and convert it from uncommercial rock into commer cial ore
 In connection with beneficiation it has been necessary to cheapen greatly the unit costs and at the same time it increased largely the metallurgical re- covery. The fact that the leaner cop per ores mostly occur in enormous ton nages warrants large capital expendi- lures and the construction of the most economical and highest class of power plants, dressing works and reduction works.
 Flotation has proved to have tre- mendously important bearing on the increased recovery of copper from sul- phide ores, and it would appear that within reasonable limits the percent age of recovery from the sulphide re- mains constant, even if, through a cheap mining method, the ore is nee essarily mixed with a proportion of overburden that is valueless. In other words, it seems practicable with cheap power and very fine grinding and the use of fiotation to dress cheap ly lean copper ore and make recov- cry of 90 percent or over of the copper existing as sulphlde in the ore wheth
 CT the ore contain 2 percent or 1 per cent of copper. In using the term fio- tatiOn 1 mean, of course, that simple and modified methods of gravity con centration are used in conjunction with it, if the sulphiGe mineral be ve- ry finely disseminated and the ratio of concentration is high; while the gray ity methods somewhat simplified re- main the major process, and Notation simply supplements it where there is some coarse sulphide and the ratio of concentration is low.
 With reference to the reduction of the copper concentrates and copper ores there has been notable improve
 ment in the increased size of the fur naces; the use of fuel oil or powdered | coal in reverberatory furnaces; the introduction of static-electric methods for avoiding dust losses: the introduc
 tion of basic lining in copper convert ing; and improvements in refining. should say, however, that the advance
 
 es in no way compares in importance to the advance made in mining lean ores and dressing them preparatory to smelling.
 Anohtre subject that we are all in terested in is the treatment of lean oxidized copper ores by teaching, and electrical precipitation of the copper with a partial regeneration of the acid .t-l,s s,,1 plants of large size are only begin ming to be installed, the outlook for the profitable recovery of copper from
 lean carbonate and silicate ores hither
 to valueless is exceedingly promising. At the present time, under most ad | vantageous conditions, have no hesi- tation in saying that IA, and possib- ly l percent, sulphide copper ore hay | ing a high ratio of concentration can
 be developed and mined by under ground methods and beneficiated at a
 profit, and that the same statement
 will probably apply in the near future | to oxidized copper ore in the form of carbonate and silicates; and just as such ore was uncommercial and worth | less 10 years ago, so I believe similar ores containing but 0.6 or or percent | copper will become commercial in the next decade.
 My theme, therefore, is that in the | conservation of our resources we | must remember that organized inves- | tigation and study of mining and met | allurgical processes play a tremen- dously important part, for if we can bring to a point of commercial use | leaner and leaner ores. so can we | greatly extend, almost indefinitely eX- | tend the life of our mineral industries We should also remember that so-
 called waste products such as slags, | tailings. cts. containing small quanti- | ties of metals, but now unprofitable, | may in turn become exceedingly profit | able They should therefore be stored
 and held for future use.
 From the view point of conservation
 we must recognize that an organized | struggle to increase our profitable re-
 serves through decreased unit costs and improvements in process and con | sequent higher recoveries presupposes | the accurate collection and tabulation | into useful form of an immense a mount of detail in both investigation
 and operation.
 The great improvements made and | those still to be attained can only | come with accurate knowledge, not
 only of costs, but of grades and re- coveries. To attain better results we
 must have complete knowledge of
 what we are doing at the present
 time In almost all metallurgical
 statements there is an item called | ''unaccountable loss" As a matter of l fact We should not recognize any such
 thing as an "unaccountable loss" We
 should only recognize that owing to | imperfect methods there is a loss
 for which we have not accounted. It is true that in well-developed
 mining organizations the principles l
 have outlined are recognized. but l
 think in the Pan American congress,
 where countries are involved whose
 mining industry is in it's infancy. at tention should he brought to these 1 principles of conservation, for we all
 know that in the early history of min | ing in this country the loss to the
 world through the waste of ore under | ground and of half-treated products has been enormous.