22 resultados para Acute toxicity of copper

em Digital Commons - Montana Tech


Relevância:

100.00% 100.00%

Publicador:

Resumo:

In order to determine the best annealing temperature at which to age-harden the alloys, hardness tests on speci­men annealed for different lengths of time at different temperatures were made.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Sulphide ores of copper are insoluble in dilute sulphuric acid leaching solutions, but a very high extraction can be obtained if the copper ore is in the oxidized condition. The problem is to convert the sulphide into the oxide form. This can be done by giving the sulphide ore an oxidizing-sulphatizing roast. Copper sulphate is soluble in water, so acid will be saved in the leaching process if copper sulphate is present. The iron in the copper sulphide ores is present as pyrite, or in combinations as bornite, or chalcopyrite.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A supply of so-called "copper pitch" ore was received by the Montana Bureau of Mines and Geology in response to a request by them from a resident of Kalispell, who had previously sent a specimen to the Bureau for a mineralogical analysis. Since this material was little known and had apparently received but little study under a reflec­ting microscope, it was thought that such a study might throw some light on the mineralogical and chemical composition of the material.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Reclaimed metals, or secondary metals, are becoming of great im­portance in the metal industries of the world. Secondary metals are an important factor in production. The increase in the secondary production of copper is due to many factors. One of these may be its permenance, that is, the metal does not corrode very readily. Another reason for increase in production is the high price paid for it.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A hydrometallurgical process for the recovery of copper from flotation concentrates has long been con­sidered an attractive possibility. The object of such a method is to produce electrolytic copper without resorting to expensive matte smelting and converting.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The purpose of this research was to continue the work of Thomas Parker, who worked on the recovery of copper and zinc from brass during the school year l934 - 1935. Since there is such a wide variety of brasses made with usually a third alloying constituent, remelt­ed scrap is suitable only for castings of wide tolerance in specifications.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Secondary Enrichment of Copper at the Madison Gold Skarn Deposit, Silver Star District, Montana. This paper focuses on the chemical reactions responsible for secondary enrichment of copper...we argue that most of the secondary Cu enrichment occurred during a late hydrothermal event that replaced the high temperature skarn mineral assemblage with hematitic jasperoid. Evidence favoring this "hypogene" Cu enrichment hypothesis is presented.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The reclamation of metals from scrap is becoming increasingly important in the metallurgical industry. Copper, because it does not corrode readily and is electronegative to most common metals, is peculiarly adapted to reclamation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The increase in hardness is attributed to the manganese silicide being precipitated from solid solution and deposited between crystal planes. The subsequent softening which occurs on prolonging the period of reheating is believed to be due to an agglomeration of the dispersed hardening agent.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The subject of the thesis was based upon the theory of precipitation or age hardening of the copper by the compound formed by the Manganese and silicon present in the ternary Cu-Mn-Si alloy. The effect of the heat treat­ment to such an alloy was to be studied and the best aging time and temperature was to be determined.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Powder metallurgy, the most recent innovation in met­allurgical process, is not a new art; although not until recently did it become a matter of general interest, this being due not only to the products formed but also to the possibilities of future developments. The manufacture and application of metal powders is now beginning to take a position as a recognized part of the science of metallurgy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Boron is an element whose metallurgical possibil­ities have never been fully investigated. The principal reason for this fact seems to lie in the difficulties encountered in preparing elemental boron and its various intermetallic compounds.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Age hardening occurs in alloys of the solid solution type containing a hardening constituent, be it metal or metallic compound, which is more soluble in the solvent phase at higher temperatures than at lower ones.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Plating of various objects with mirror-like surfaces of chromium, nickel, and other metals has expanded considerably during the past decade, and now ranks as an important enterprise, particularly with respect to the automotive industry.