Refining Electrolytic Copper
The object of refining copper in the reverberatory furnace is to obtain a metal which will have the highest attainable degree of malleability, ductility and electric conductivity, and present at the same time a level surface when it solidifies in the mold after casting. These desirable physical properties are governed by the character of the […]
Roasting Galena Concentrate with Lime
Lime Roasting is a term proposed by Ingalls for the operation of forcing air under pressure through a mixture of galena and lime at the kindling-temperature with the object of oxidizing lead and sulphur and of fritting or fusing the charge. If finely-divided galena were treated in this manner without the addition of lime, the […]
Effect of High Litharge & Silver Assay Crucible
In the crucible-method of assaying ores for silver a certain amount of litharge is essential to supply sufficient lead to collect the precious metals. The object of this paper is to point out that the use of a large excess of litharge in the assay of some ores will give results for silver that are […]
Laboratory Gold Ore Chlorination Testing Procedure
Experience has shown how difficult it is to obtain information regarding laboratory tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore chosen was […]
Tin Ore Processing
The methods employed in dressing the tin ore up to the required percentage of purity depend mainly on the type of ore crushed. These may be briefly divided into two distinct classes—viz., a free milling ore and a complex milling ore. In the former the ore is practically free from the common metallic sulphides, such […]
Small Mining Drills
The purpose of this paper is to discuss the relative merits of the large 3 1/8-in. machine and the small mining drill 2¼-in. tappet machine in driving development-headings; and although the data here presented were obtained from cross-cut headings alone, experience has shown that the results are equally true in drifting, raising and winzing. Recently […]
Refining Base Metal Bullion & By-Product Treatment (Pb, Cu, Zn) Bars
Here is a short account of the treatment of the base bullion for the recovery of lead, silver, and gold, and for the treatment of by-products. Appended is a short description of the chief facilities of plant which have been adopted to overcome the main difficulties in the refining of lead. The difficulty of obtaining fair samples […]
Gold Leaching of Pyrite Concentrate
The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill […]
Iron Crystallography
We have already devoted two previous memoirs to this question. In the first we collated and discussed the existing literature on the subject; in the second, we described the crystalline forms obtained by the reduction, at different temperatures, of ferrous chloride by hydrogen or by zinc-vapor. The conclusion from these researches was that the three […]
Cost Accounting in Mining
In the zeal for opening up new ore-bodies, or for extracting the ore from attractive bodies already opened up, we very often lose sight of the fact, that, after all, the operation of a mine is a business proposition, pure and simple, and, for the best working-results, should be treated upon a strict business basis. […]