Roasting and Leaching Bulk Copper-Zinc Sulfide Concentrates with the Subsequent Recovery of the Metals by Electrolysis

The aim of this research was to investigate the possibilities of roasting and leaching a bulk copper-zinc sulfide concentrate, and the subsequent separation of the metals from the leach solution by electro­lytic deposition.

A Study of the Effect of Third Metals on the Wetting Properties of Solders

Solders are not new alloys, since they were known in late Roman times when they were mentioned by Pliny. These solders differed very little from our modern ones. Tertiarium, consisting of one part of tin to two parts of lead, is known today as plumbers solder; and argentarium, consisting of equal parts of lend and tin, is still extensively used for many purposes.

The Electrical Resistance of Metals and Alloys in Their Hard and Soft States

It is known that the electrical resistance of annealed metals is usually smaller than that of metals in their cold worked state. The curve showing the relation between electrical resistance and annealing temperature reaches a minimum; continued annealing at higher temperature produces an increase in the electrical resistance. In the case of alloys it has been noted that a second decrease occurs at higher annealing temperature. The following work corroborates the observance of previous investigations. The electrical resistance of cold worked copper, gold, nickel, and iron decreased with annealing and then increased, the minimum being around 300° C. or 400° C. Monel metal showed a minimum resistance followed by an increase which in turn was followed by a second decrease.

Geochemistry and Stable Isotopes of Surface Water and Groundwater in the Continental Pit in Butte, Montana, USA

The Continental porphyry Cu‐Mo mine, located 2 km east of the famous Berkeley Pit lake of Butte, Montana, contains two small lakes that vary in size depending on mining activity. In contrast to the acidic Berkeley Pit lake, the Continental Pit waters have near-neutral pH and relatively low metal concentrations. The main reason is geological: whereas the Berkeley Pit mined highly‐altered granite rich in pyrite with no neutralizing potential, the Continental Pit is mining weakly‐altered granite with lower pyrite concentrations and up to 1‐2% hydrothermal calcite. The purpose of this study was to gather and interpret information that bears on the chemistry of surface water and groundwater in the active Continental Pit. Pre‐existing chemistry data from sampling of the Continental Pit were compiled from the Montana Bureau of Mines and Geology and Montana Department of Environmental Quality records. In addition, in March of 2013, new water samples were collected from the mine’s main dewatering well, the Sarsfield well, and a nearby acidic seep (Pavilion Seep) and analyzed for trace metals and several stable isotopes, including dD and d18O of water, d13C of dissolved inorganic carbon, and d34S of dissolved sulfate. In December 2013, several soil samples were collected from the shore of the frozen pit lake and surrounding area. The soil samples were analyzed using X‐ray diffraction to determine mineral content. Based on Visual Minteq modeling, water in the Continental Pit lake is near equilibrium with a number of carbonate, sulfate, and molybdate minerals, including calcite, dolomite, rhodochrosite (MnCO3), brochantite (CuSO4·3Cu(OH)2), malachite (Cu2CO3(OH)2), hydrozincite (Zn5(CO3)2(OH)6), gypsum, and powellite (CaMoO4). The fact that these minerals are close to equilibrium suggests that they are present on the weathered mine walls and/or in the sediment of the surface water ponds. X‐Ray Diffraction (XRD) analysis of the pond “beach” sample failed to show any discrete metal‐bearing phases. One of the soil samples collected higher in the mine, near an area of active weathering of chalcocite‐rich ore, contained over 50% chalcanthite (CuSO4·5H2O). This water‐soluble copper salt is easily dissolved in water, and is probably a major source of copper to the pond and underlying groundwater system. However, concentrations of copper in the latter are probably controlled by other, less‐soluble minerals, such as brochantite or malachite. Although the acidity of the Pavilion Seep is high (~ 11 meq/L), the flow is much less than the Sarsfield Well at the current time. Thus, the pH, major and minor element chemistry in the Continental Pit lakes are buffered by calcite and other carbonate minerals. For the Continental Pit waters to become acidic, the influx of acidic seepage (e.g., Pavilion Seep) would need to increase substantially over its present volume.

Precipitation of Gold, Silver, and Copper from Cyanide Solutions on Activated Charcoal.

Charcoal has been known for a considerable length of time to have the property of recovering gold, silver, and copper from cyanide solutions of these metals. Quantita­tive data that may shed light on the mechanism of the re­moval of these metals is very limited except that char­coal in a form known as activated has the power to abstract gold and silver in considerable quantities from the above solutions.

Investigation of a Method for Extraction of Indium from Zinc Flue Dust.

In metallurgical practice today some of the relatively rare metal Indium is recovered as a by-product from the ores of other metals. Indium is a soft, silvery—white metal belonging to the third group of the periodic classification. It is situated just above tin in the electrochemical series.

A Study of Metallic Eutectics

All of the metals have definite melting points. When a metal is heated above the melting point, it exists as a liquid. Now if the melt is allowed to cool, it will solidify when a temperature corresponding to the melting point is reached. However, if one metal is added to another metal, both of which are mutually soluble in the liquid state, a certain effect can be noted. The melt will not solid­ify when the melting point of the pure metal is reached, but will freeze at a lower temperature.

The Electrolytic Recovery of Copper and Zinc from Scrap Brass with Special Reference to Lead-Bearing Brass.

Several methods have been investigated, with some success, for treating scrap brass to recover copper and zinc, either as pure metals or as salts of the metals. One of the more promising of these methods is electrolysis in sulfate solution for the recovery of pure copper and zinc.