The use of zinc dust for precipitating the precious metals from cyanide solutions is well established now in many places, and has many advantages over the shavings method of precipitation. Although much work has been done on methods of testing zinc dust, as yet no absolutely positive test has been devised to determine the value … Read more
Auxiliaries Actuated by Oil under 135 lb. Pressure When steam is used by the auxiliaries, which operate brakes, clutches, etc., it constitutes an important percentage of the total power used by the engine. The condensation is great and continuous, and since the controlling valves can have no lap, but must be set “line and line,” … Read more
The ore deposits of the Warren district, in which the mines of the Copper Queen Consolidated Mining Co. are situated, have been described in a number of technical publications, and will not be discussed here in detail. Certain of their characteristics, however, control methods of underground transportation and hoisting of ore. In the Copper Queen … Read more
The cams at present universally used in stamp mills lift the tappets with an involute form of curve, to which the surface of the tappet is always tangent; moreover, the line of contact between tappet and cam, if produced, would pass through the center of the stem. This is no doubt a desirable feature, but … Read more
The low cost of mining was the principal consideration, since, with mercury’s price per pound, the total gross value of the ore did not exceed too much per ton. Square setting and filling was out of the question, so various attempts with cheap methods were made, among them a shrinkage system. None gave satisfaction on account … Read more
Last year this Institute was good enough to accept some remarks by the writer regarding sound steel, entitled Plant for Hadfield Method of Producing Sound Steel Ingots, being a continuation of a research in which for some time the writer has been engaged, and full particulars of which were submitted in papers entitled A New … Read more
In drilling for water and oil to reasonable depths through the generally soft yielding clay and sand formation of the Coastal Plain of Texas, Louisiana, and Mississippi, the rotating method of drilling was adopted, principally on account of the easy and quick penetration, and the low cost of the drilling plant. In favorable ground, free … Read more
The Copper Queen mine is composed of seven divisions which are operated through the following shafts: The workings of the different shafts are connected by motor-haulage drifts on the even numbered levels. The general location of the orebodies and workings is illustrated by the vertical projection of orebodies of the district as shown in Fig. … Read more
The stresses, in the simplest structures are often those we find most difficult to analyze. The most complex condition in mine stresses is found in simple tunnels where the roof, the sides, and the floor are a monolith. The functions of the parts are like the parts themselves not distinct and specialized, and the problems … Read more
Many assay methods for the determination of gold or silver, or both, in cyanide solutions have been published, which with care in manipulation, and modification in some cases, will give results that are satisfactory. It is possible to classify or group these methods as follows: Evaporating the solution in a porcelain or agate-ware dish containing … Read more