Search Documents

By John M. Devine

The severe corrosion of equipment that is caused by the presence of hydrogen sulphide in oil and gas has been described in detail by several authors. Such corrosion, termed "low-temperature hydrogen sulphide corrosion", presents a somewhat different problem from the "high-temperature hydrogen sulphide corrosion" that is encountered in refinery operation and which has been described by various-investigators of refinery corrosion.

Jan 1, 1932

By M. C. Makepeace

"It is the objective of designed experiments to obtain more information for less material and process cost than can be obtained by traditional experimentation. In this paper, the fundamental concepts on which the statistical design of experiments is based are briefly re-viewed according to the following outline: The Experiment The Design The Analysis Two simple 2"" factorial experiments are presented as examples."

Jan 1, 1967

By C Hall, J L. Mauk

New 40Ar/39Ar dates of vein and wall rock adularia from seven epithermal deposits and one porphyry copper prospect help constrain the ages of mineralisation in the Hauraki Goldfield. Vein adularia from the Paritu region yielded a single 40Ar/39Ar plateau date of 16.315 ¦ 0.066 Ma. Five 40Ar/39Ar plateau dates of three samples of vein adularia from the Opitonui deposit overlap within error to yield a preferred age of 13.149 ¦ 0.016 Ma. Two samples of vein adularia from the Night Reef at the Broken Hills deposit yield exceptionally flat 40Ar/39Ar plateaus, and all dates overlap within error to provide an age of 7.121 ¦ 0.010 Ma. Two 40Ar/39Ar plateau dates of one sample of vein adularia from the Wharekirauponga deposit overlap within error to provide an age of 6.318 ¦ 0.061 Ma. Four 40Ar/39Ar plateau dates of three samples of vein adularia from the Maratoto deposit overlap within error to provide an age of 6.411 ¦ 0.022 Ma. Two samples of adularia from altered wall rock at the Sovereign deposit yield three 40Ar/39Ar plateau dates that range from 6.547 ¦ 0.021 to 6.806 ¦ 0.028 Ma. This suggests that mineralisation formed around 6.6 Ma, but the results are complicated because the adularia contains minor illite that post-dates adularia formation. Results from the Karangahake deposit are complex. Two samples of vein adularia yield three 40Ar/39Ar plateau dates that range from 6.116 ¦ 0.116 to 6.901 ¦ 0.101 Ma, whereas one sample of wall rock adularia that contains minor late illite yields two 40Ar/39Ar plateau dates that overlap within error to provide a date of 5.734 ¦ 0.041. The range of dates indicates that more work is necessary to understand the history of mineralisation at this deposit. Two samples of vein adularia from the Tui deposit yield four 40Ar/39Ar plateau dates that overlap within error to provide an age of 5.714 ¦ 0.017 Ma. These results confirm previous work that indicates that the ages of epithermal deposits young southward in the Hauraki Goldfield. These results are also consistent with previously postulated different ages for deposits hosted in Kuaotunu Subgroup rocks in the northern goldfield (>10 Ma), and deposits hosted in Waiwawa Subgroup rocks in the southern goldfield (7.1 to 5.7 Ma).

Jan 1, 2005

By L. B. Berger

Tests and observations of a Diesel-powered locomotive used for under-ground haulage, in a-clay mine were made by representatives-of the Bureau of Mines .primarily to determine the composition of the exhaust gases produced by the engine under actual haulage conditions-and to determine the effects of the operation on the quality of the mine atmosphere. In addition to ascertaining these conditional t proved interesting to analyze the test, data in regard to certain other performance, characteristics of the engine. This report presents results of tests of the mine locomotive, prefaced by a brief resume of the performance characteristics of Diesel engines to facilitate discussion.

Jan 1, 1948

By David J. Mack

A survey and critical appraisal of published information about Young's modulus was originally made by the writer because of a complete lack of information about this very important quantity in works on. mechanics, physical metallurgy, physics, and other sciences. It was felt that a comprehensive summary of such information about Young's modulus might be of general interest and may suggest new problems or lines of attack on other problems that involve E. Hence this paper has been prepared even though it is only a review, with no new ideas or experimental data. The references are only those used in assembling the paper. No attempt was made to compile a complete bibliography on the subject of Young's modulus. CalculatioX oP YouNg's Modulus from Theoretical or Empirical CoNsidera-tions Many attempts have been made to compute E from theoretical considerations. The earliest calculations were probably those of Tomlenson (1883) and Souther-land (1891), but Fess'enden4',~ made extensive calculations a few years later and arrived at the relationship: £ = 78.TOw(i)* where V is the atomic volume. In 1923, Peczalski, working from the same standpoint but with more information available on atomic structure, arrived at an identical relationship, which he expressed as: where B is a constant of value about 8 . 107, p is density and mis atomic weight; the atomic volume, of course, being ml p. Portevind4 immediately pointcd out that while the equations of Fessenden and Peczalski were true of the common metals, they gave low values for the refractory metals with high moduli (Fig. I). He showed (Fig. 2) that much better concordance was obtained by means of an empirical equation of the form: F- KT" where K is a constant; T the absolute melting point; V, atomic volume, and a and b constants of value approximately I and 2 respectively. This constant K in the Portevin equation is not necessarily the same for all elements, as shown by Thompson. Other equations for E based upon theoretical considerations have been derived by Honda and Yamada49 and Lasareff.50 The most recent calculations of elastic moduli based upon quantum mechanics are probably those of Fuchs He extended the method of Wigner and Seitz for calculating the lattice energy and compressibility of monovalent metals and computed the elastic constants of lithium, 18

Jan 1, 1946

By G. W. Poling

This paper evaluates current environmental protection legislation, guidelines and criteria, focusing mainly on the land and water disposal of mill tailings. Effluent criteria and regulatory mechanisms are proposed, and submarine tailing disposal is discussed at length. The importance of basing regulations on the best available rationale is stressed.

Jan 1, 1979

This report contains the papers presented at the Technology Transfer Seminar on Ground Control Aspects of Coal Mine Design held by the Bureau of Mines on March 6, 1973, in Lexington, Ky. Seminar attendance consisted of representatives from the coal mining industry, universities, mining consultants, instrument manufacturers, and local, State, and Federal Government. The purpose of this meeting, one of a series of Technology Transfer seminars, was to provide the coal mining industry with detailed information about recently developed techniques, equipment, and instruments which can be used in the solution of coal mine design problems and to discuss results and direction of research in mine design. The report includes opening remarks by Joseph J. Yancik, Acting Assistant Director--Mining; an overview of the Federal Bureau of mines approach to mine design; three papers an problems associated with the design of panels; five papers on coal mine roof problems; three papers on long wall problems; and the comments made by- the participants on the Bureau-industry panel discussion.

Jan 1, 1974

By David A. Hill, James R. Wait

This report contains a summary of analytical research on electromagnetic methods of nondestructive testing of cylindrical conductors. The principal objective is to provide theoretical insight to the operation of electromagnetic sensing of the internal properties of wire ropes that are used extensively in mine hoists. An overall review of past work is also included.

By W. J. Kroll

This report on the bibliography of zirconium has been confined to those publications and patents that appear to be useful in the commercial development of the metal, both the malleable and the nonmalleable. The methods of production have been stressed and special attention has been given to the alloys. Compounds of importance, like the oxide and chloride, for the manufacture of the metal or of the alloys have been considered. The use of the oxide in refractories anal in the glass and porcelain industries has been omitted. The present survey is critical; that is to say, an attempt has been made to evaluate the effectiveness of suggestions made in the literature. The exhaustive work of Marden and Richy, Bureau of Mines Bulletin 186, published in 1921, has been taken as a base to start from with the intention of bringing the subject up to date with material published in the last 24 years. During this time there was considerable 'advance in the preparation of the metal and Its alloys, and in the development of new uses. On the other hand, there was little progress in the methods of decomposing the ores, so that the chapter on this latter phase is necessarily short.

Jan 1, 1946

By Jerry C. Tien

China?s remarkable levels of economic growth during the past three decades have lifted almost 300 million people out of poverty. This amazing achievement has placed an increasing demand on energy and minerals, especially coal, which supplies 68.7 percent of China?s energy (June 2011). It is estimated that China mined more than 3 Gt (3.3 billion st) of coal in 2010, three times as much when compared to merely 10 years earlier. Such an impressive achievement does not come without major costs ?? including concerns with mine safety and an increasing number of occupational illnesses due to fast growth. This article reports on one of the major safety concerns in China?s coal mining, dust and dust control practices, and known cases of caol worker?s pneumoconiosis affiliated with prolonged exposure to excessive coal dusts. The exact size of China?s mining industry is not known, but it is estimated the coal industry is at least five-million people strong, and the metal and nonmetals industry probably employs another three million people. To meet increasing energy demand, China mined more than 3.1 Gt (3.4 billion st) of coal in 2010 from its 15,000 plus coal operations1, most of which are small- to medium-sized operations with annual coal productions ranging from a few thousand tons to 300 kt (330,000 st). These small coal operations are typically in remote areas, inadequately engineered, poorly ventilated and still using rudimentary drilling and blasting mining methods employing antiquated mining equipment and, presenting safety concerns, i.e., methane and dust explosions.

Jan 1, 2011

By Timothy A. Clancy

To help reduce the Nation's dependence on imported chromite, the Bureau of Mines is conducting research on the use of dolomites as an alternate material. Dolomite is a plentiful domestic resource and offers certain advantages as a refractory raw material. A review of the literature has indicated that there are many sources of high-purity dolomite in this country and that European nations use a greater proportion of dolomite refractories, primarily in steelmaking, than the United States, The Bureau of Mines characterized 14 domestic dolomites as to chemistry, density, mineralogy, microstructure, and thermal behavior, to develop baseline data on their suitability as refractory raw materials.

Jan 1, 1983

By Alfred E. Schwaneke

A new high-temperature soft soldering system has been developed by the Bureau of Mines for use on copper, copper alloys, and low-carbon steel; the method is applicable to automobile radiators and home appliances. The system uses a unique sacrificial metal coating method to promote spontaneous wetting and spreading of zinc and zinc alloy solder: on metallic substrates. The 10-5 to 10-6 cm thick, electroplated or sputtered, sacrificial nickel coating is absorbed by the molten filler alloy during soldering and produces a direct solder-substrate metallic bond. Preliminary measurements on butt joints with copper members give tensile strengths up to 22,000 psi at room temperature using 95 Zn-5 Al alloy as solder. Spontaneous wetting, spreading, and capillary penetration are extremely rapid and produce joints as easily as 50-50 tin-lead solders. Recrystallization or annealing of the wrought copper joint members is negligible at the soldering temperatures of 450° to 490° C and lower. A list of fluxes and solder alloys is included in the report.

Jan 1, 1970

By Gibbs R

The objective of this paper is to provide a broad qualitative perspective of the needs and costs of infrastructure associated with typical mining projects. Infrastructure may be defined as anything necessary for the development and operation of a project, which is peripheral to the basic extraction, handling and processing of material. As depicted in Figure 1, infrastructure acts as the link between the technological heart of a project and the outside world.

Jan 1, 1990

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Mineral resource information indicates that in the Gore Range the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range. Limestone, marble, sand and gravel, rock for crushed aggregate, and other industrial rocks have been recently mined or Quarried in the Forrest, and will likely be mined or quarried in the near future. Currently coal is being produced at one mine in the Forest, and extensive identified coal resources are located in the Forest. Parts of four known gas fields lie within the Forest west of Glenwood Springs; there is current production at one field.

Jan 1, 1990

The mineralogy of nickel slags from the flash smelter of Western Mining Corporation Ltd. at Kalgoorlie was studied. Residual magnesium silicates in the sulphide concentrates raise the melting point of the slag and result in the formation of magnesium-rich olivines. Addition of lime lowered the melting point, and, in slowly cooled slags, resulted in the formation of a pyroxene.Magnetite and sulphides were also present in all slags.The converter slags contained an olivine near fayalite in composition, together with wiistite, magnetite, and a little sulphide.Accretions from the hearth of the flash furnace were largely composed of magnetite with subsidiary olivine similar in composition to those of the flash furnace slags.Wall deposits, however, were largely composed of nickel ferrite and nickel-iron olivines.

Jan 1, 1976

By L D. Queen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Tifalmin porphyry copper district is located in the Star Mountains roughly 35 km north-east of the Ok Tedi mine. The district is a cluster of temporally and geochemically related porphyry copper deposits and their associated skarns. It covers an area of roughly 10 × 6 km and comprises at least three intrusions (Olgal, Futik and Kum Kom) where drilling has demonstrated the presence of porphyry copper mineralisation, and another three intrusions (Rattatat, Unfin and Pad 48) where porphyry copper mineralisation is strongly suggested by surface investigations and geochemical or geophysical signatures.Copper and gold mineralisation was first discovered in the area in the 1960s as part of the regional exploration program by Kennecott that located Ok Tedi. The mineralisation is associated with poly-phase porphyritic diorites, quartz diorites and tonalites that intrude the Upper Eocene to Middle Miocene Darai limestone and underlying Cretaceous to Eocene Feing Group. Radiometric K-Ar and U-Pb zircon ages cluster between 4 and 2 Ma for both the mineralised and post-mineral intrusions. In addition to porphyry-type mineralisation, variable amounts of calc-silicate and/or magnetite skarn occur near the contact of most of the intrusions. Mineralisation in the Olgal and Futik porphyries occurs as chalcopyrite replacement of mafic minerals and in a stockwork of micro-veinlets. Mineralisation mostly occurs in the intrusions but is also observed in hornfelsed siltstones and sandstones of the Feing Group on the southern margin of the Olgal intrusive body. Quartz veining is uncommon. Secondary magnetite is commonly associated with the highest copper and gold grades. Sericitic alteration is most prominent in the mineralised hornfels. Structurally, the area is dominated by syn- to post-mineralisation thrusting from the north. At least one of the deposits (Olgal) appears to be truncated at depth by a thrust fault.CITATION:Queen, L D, 2015. The Tifalmin porphyry copper gold district, Star Mountains, Western Papua New Guinea , in Proceedings PACRIM 2015 Congress, pp 357–360 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Jinhui Li

Silver is a very important metal used in a wide range of applications. It is necessary to recovery of Ag from electronic wastes for increasing of Ag price and circumstance protection. For separating and recycling Ag from Ag-Cu composite materials, thermodynamic data of reaction is calculated and some experiments have been proceeded with Ag-Cu composite material scraps, time, temperature, nitric-sulfuric mixed acid volume ratio and the volume ration of mixed acid vs. water have been discussed. The results show that the optimization conditions is that nitric-sulfuric mixed acid volume ratio 5:95, volume ratio of mixed acid vs. water 10:1, temperature 55?, time 25min. In the conditions, Ag can be selectively leached from Cu-based composite material, Cu base is not eroded nearly.

Jan 1, 2009

By Paulo Braga, Carlos Junior, Silvia França

"Lithium is the lightest of the metals, with high reactivity and great electrochemical potential. It has a low thermal expansion coefficient and high caloric value, and it forms very light and resistant aluminium alloys. These properties make lithium an attractive element for use in battery manufacture and glass and ceramics production, in addition to its applications in the aeronautic industry. Today, two sources of raw material are economically viable for lithium production: pegmatite rocks and brine. The world production, in 2012, was approximately 150,000 tons of LCE (lithium carbonate equivalent), almost triple the production in 2000. The forecasted consumption for the current year, 2013, was approximately 162,000 tons of LCE, and for 2020, it could be as much as 280,000 tons of LCE, stimulated essentially by the growth of world production of electric (EV), hybrid (HEV) and hybrid plug-in vehicles (PHEV), the batteries of which are based on Li-ions. With the growth of world demand and increasing prices, lithium minerals such as spodumene, petalite and amblygonite, once considered uneconomical for the production of lithium carbonate, are regaining their economic value. New projects to produce lithium compounds based on mineral sources are being developed in many countries, aiming to produce battery-grade lithium carbonate (99.95% Li2CO3). Although Brazil has large lithium pegmatite reserves, the domestic production of lithium carbonate and hydroxide is very low, at approximately 600 tons of LCE, which represents 0.4% of the world production. The application of these products is mostly in the grease and ceramic industries. The national lithium market is under government protection due to its potential use for nuclear purposes. Thus, the industrialization activities and import and export of ores and lithium minerals, as well as organic and inorganic products, such as metallic lithium and lithium alloys, are controlled by the National Commission for Nuclear Energy (Comissão Nacional de Energia Nuclear - CNEN). The objectives of this work to quantify the real lithium demand in the Brazilian market, considering that a large amount of lithium is indirectly imported in the form of the Li-ion batteries used in equipment such as mobile phones, cameras, tablets, notebooks and e-bikes, and to compare this demand with the current national production of LCE. Finally, some technological alternatives will be discussed, with the aim of increasing the competitiveness of the lithium industry in Brazil."

Jan 1, 2014

By B. Oraee

Accurate estimation of equipment costs is a key factor in feasibility study and evaluation of design alternatives of mining projects. In this paper, capital and operation costs of backhoe loaders are estimated using multiple linear regression (MLR), based on principle component analysis (PCA). These cost functions are consisted of five independent variables; bucket size, digging depth, dump height, weight and horse power. The MLR is conducted in two steps. At the first correlation between independent variables is omitted using PCA technique. Thereafter, MLR functions are established using selected significant PCs and total cost functions are constituted as functions of initial variables. At the end, accuracy of functions are evaluated using mean absolute error rate method.

Jan 1, 2011

By Jack L. Henry

The monocarbide region of the ternary system U-C-O has been investigated at 1,700° C as the first phase of a more extensive study of a portion of the four-component system U-C-O-N. An area bounded by the following compositional limits in atomic percent was studied: U, 44 to 55; C, 30 to 60; 0, 0.2 to 20. Compacts composed of mixtures of uranium, graphite, and uranium dioxide powders were sintered at 1,700° C under an equilibrium pressure of carbon monoxide to produce uranium oxycarbide specimens having a variety of compositions. Sintered specimens were evaluated by X-ray, chemical analysis, and ceramographic techniques. Solid-solution boundaries and phase relations have been established, and the effects of composition on the lattice parameter as well as the decomposition pressure have been investigated. Oxygen can be substituted for carbon in stoichiometric uranium monocarbide to the extent of about 17 atomic percent at 1,700° C. The composition range of the oxycarbide solid solution extends from about 48 to 51 atomic percent uranium in the low oxygen region. Above 10 atomic percent oxygen the composition range narrows to less than 1 atomic percent uranium. Carbon monoxide exists as a gaseous phase in equilibrium with all compositions which contain oxygen. Five separate phase fields were found bounding the solid-solution area. Other phases within this portion of the system include uranium, uranium dioxide, uranium dicarbide, and uranium sesquicarbide. Decomposition pressures of oxycarbide compositions at 1,700° C have been found to vary from a few microns for stoichiometric and uranium-rich compositions to 35 torr for carbon-oxygen-rich specimens. Lattice parameters were found to depend upon the U to C + 0 ratio as well upon the extent of substitution of oxygen into the stoichiometric monocarbide lattice.

Jan 1, 1967