17 resultados para Cumul index and Quebec longitudinal study of child development
em Digital Commons - Montana Tech
Resumo:
The smelting of complex lead ores is a difficult operation, especially when they contain considerable amounts of iron and zinc. When these ores are smelted, all of the zinc, which is valuable and well worth recovering, goes into the slag. With the advent of the flotation processes, and the ability of these processes to concentrate the lead and zinc minerals into separate products, the smelting of complex lead ores was to a great extent simplified.
Resumo:
As the method or analysis used up to the present time has failed to give quantitative results in determining the composition of zinc cyanide baths, conductometric methods were adopted in this study. Supplementary tests were also carried out in this investigation.
Resumo:
Research has been undertaken both under Government and private auspices in an endeavor to develop uses for bentonite. Perhaps, the work done to date has had only in consideration the possible industrial importance of bentonite. No simple, quick methods for the determination of the properties or qualities of any particular bentonite have been developed. In an attempt to establish whether or not there is a means of making rapid simple determinations of the quality of Montana bentonitic clays, and in particular, with regard to the uses to which the clays may be suited. The problem also involves a study of Montana bentonite, and a comparison of it with the standard accepted bentonites and fullers earth on the market today.
Resumo:
A microscopic investigation of the Montana silver minerals was conducted. This study consisted mainly of identifying the silver and silver-bearing minerals and of determining their paragenetic relationships. The increasing amount of research in which the reflecting microscope is employed is evidence of the great value of this method of approach in the solution of problems of paragenesis of the opaque minerals.
Resumo:
The accepted chemical reactions in the dissolution of gold by cyanide solutions require the presence of gold, cyanide, water, and oxygen. The importance of dissolved oxygen in cyanide solutions as a factor is recognized by those familiar with cyanidation. Manufacturers of cyanidation equipment realize the necessity of oxygen, as shown by the appliances they have developed which are attached to the agitators in order to saturate the cyanide solutions with air.
Resumo:
The purpose of this paper is to furnish a qualitative method of comparing the degree of wetting of various solders upon different plate metals when several fluxes are used.
Resumo:
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.
Resumo:
The ore under investigation in this thesis is a copper-zinc ore which came from the state of New Mexico. The exact location is unobtainable. The purpose of the investigation was to determine the most effective means of concentration of the valuable minerals present in the ore.
Resumo:
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.
Resumo:
Considerable work has been done investigating the freezing point curves of fused salts, but little has been written describing the appearance of their eutectic structures when observed under the microscope.
Resumo:
The purpose of the investigation was to determine the most effective means of concentrating the manganese in the ore. The study was that of identification of the minerals present. This showed the presence of oxides of manganese and iron, and carbonates of calcium and manganese. Methods of investigation were planned to determined whether the ore could be concentrated effectively by gravity concentration methods.
Resumo:
The presence of graphite in the ore of the Missouri-McKee Mine has made its treatment by the methods now used quite unsatisfactory. The study was undertaken to develop a new flow sheet which would give a high recovery and yet be economical enough to handle low grade material.
Resumo:
With an eye to the future development of its resources, the large deposits of low-grade manganese ore within Montana's boundaries show great promise of developing an important industry. With the present war demands and the possibility of a future market it is essential that work expended to utilize this important mineral.
Resumo:
In 1947, out of the 100,000 long tons of tin consumed in the United States, 25,000 tons went into solder. Tin plate took 39,000 tons while babbit, bronze and collapsible tubes accounted for approximately 17,000 tons. Solder ranked second to tin plate and required more than the next three major uses combined.
Resumo:
The object of casehardening is to produce articles of steel having a tough or ductile interior and a hard surface. Quenching produces a surface somewhat harder than the interior, but in order to obtain a high surface hardness, the percentage of alloying elements in the steel must be raised to such an extent that the core or central portion becomes hard and brittle also.