The Ketchikan miner., 1909-03-27
What Forms Good
 Smelling Copper Ore

The state Mining Bureau Of CalltOr- nia has sent out comprehensive arti- Gle on "what constitutes good smelt-
 ing copper oren by Dr. Hausmann, from which we take the following;
 For copper ores smelling is almost the only treatment to be considered :
 it is applicable to all of them without exception, although they are not equally we'll adapted to it. The ques- tion of smelling at the mine is of greater importance for copper than for gold or silver ores, because the former can never attain such high val ues as the latter. While gold and sl- yer ores may carry metals enough to be worth many thousands of dollars and bear considerable expense for transportation. ton of 20 per cent copper ore al 30 cents a pound of cop ner IS worth sl20 only: but such a grade and price are rather exceptional and 10 per cent ore, copper at b cents.
 ID many localities would not pay to ship. Large hodes of copper ore are, however, usually of much lower grade, and the owner is confronted by the al- ternative to close tine mine or to smelt the ore on the spot. In such case it is of import to know whether this can be done. and it may not be out of place to state hriefy the conditions for $ lccessful srelting.
 The frst condition is, of course, a sufficient percentage of copper, assum- ing an ore not containing enough golC nr silver to tffrct the value. Thee is lowest limit, but no tiXed standard ior all plac, < it may he possible in -ome localities 10 treat ore as low as D 1T cent. while in others 10 per cent may not be of sufficient grade. Suppos- ing the ore to he of fair grade, the c st of smeiting can be calculated, if the factors hy which it is determined. the cost of fuel. labor, power. iiuxes and trarspoi tatiun, are kpogn. but it requires knor ledge Of smelling ard the chemical composition of the ore and presents problem which the m talluigi,t must solve for every pa, uar case and locality. Often we h ar people sre;k about self-6uxing ore who evidently do not know wha. constitute, th desirable quality, and for the better understanding of this important qui siion general idea oi the principle- involved is given.
 The object u smelling is the sepsr- alton of q metal from the material with which ii is mechanically mixed or chemically combined. and this is accomplished by uniting the necessary mineral in such proportions that they will smeIt and 'orn liquitls l-lagsl ol less specific gravity than the metal. which they permit to sink through and gather on the bottom. If the metal is not present in the ore as -ucii it is either converted into the metal lie state ny the chemical action of the lux and fuel, or recovered in some form which requires subsequent treat ment or refining. But the principle Of separation by specific gravity re- mains the same, and the more or less prefect recovery Of the metal depc nds on the proper condition Of the sIag
 Be, ause the metal represents d small port.uu of the ore the making of q slay free from metal and easily re- moved is the main object of the metalIurg;st. The material forming the slag consists of two groups. the ac j sllica (quartz) and the basic, the oxides of the neavy metals. iron, man. ganese, eff., al ihy cartby bases lime, magnesia, etc., which mJ-t bs co nh ned in certain proportions in order 10 answer ths pusp se Tor wl;ich lags are made. because they are in- Iusible by themselves Silica. non. and lime furnish Lie bulk of li,e sltg- making ma,erial in copper ores and the basis for the slag calculation. gi'ira requires q certain quantity ol the basic group, which may De iron. manganese, lime, etc., bot exnerience has shoan tha. ths oxides oi the heavy