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By G. A. Koenig, Moritz Stockder

Locality and Geological Occurrence.—The Atpine region of Southwest. Colorado. cort~prieiog the San Juan and Uncon~paghre Mountains, is con~posed of a deeply eroded sheet of acid eruptive rocks, overlying in part gneissic schiets, and in part limestones and sandstones, including portions of the Silurian, Devonian, arid Carboniferous systems. The section is clearly and beautifully exposed along the Uncompghre River from its headwaters to its exit from the mountains. The river's course from the town of Ouray towards the Los Pinos agency is due north, and four miles from Ouray, in this directiou, the Uocampaglire receives from the east the Red Casm Creek. Following up the narrow canon we find the section through white. sandotone in strata dipping to the north and west, and belonging either to the lower or middle Devonian system. Presently the steep cafion-like character of the ravine gives place to more gentle slopes, ad we have entered crysralline rock—porphyry. The contact is well marked, for the sandsbne, to a depth of from six to ten feet, resembles quartzite, i. e., is serui'fusd. Ascending still higher, a small

Jan 1, 1881

By H. R. Thresh, A. F. Crawley, D. W. G. White

The densities of liquid tin, lead, and Sn-Pb alloys have been measured over a range of temperature above the liquidus. In all cases, data can be adequately represented by an equation of the type p = a + bT. For pure tin, the values of a and b are, respectively, 7.139 and 7.125 x 10-4, and for pure lead, 11.060 and 12.220 x 10-4. At constant temperature, molar volumes in the Sn-Pb system vary linearly with composition. DURING the course of a long-term program at the Department of Energy, Mines and Resources, Ottawa, Canada, the densities of liquid tin, lead, and Pb-Sn alloys were studied. The work reported herein draws on two sets of results independently achieved by Thresh, on the one hand, and by Crawley and White, on the other. EXPERIMENT The method and apparatus were originated by Thresh and have been described in detail in Mines Branch reports.172 In operation, the 14 cu cm graphite pycnometer is put in the furnace as shown in Fig. 1 after a machined charge has been placed inside the pycnometer and the lid screwed down. The dimensions of the charge are such that, upon melting, a small excess of liquid metal is discharged through the capillary hole to displace the weighted float above. When the pycnometer has been equilibrated at the experimental temperature, the

Jan 1, 1969

By T. Egleston

Although the success of metallurgical operations depends so largely on the possibility of finding proper refractory materials, which enter so prominently into the cost of their operations, it can hardly be said that our knowledge of them is in a very satisfactory condition, or even that we know very much about them, beyond a few facts which have been gathered through their use. Experience, as a general thing, is an excellent master, but the requirements of

By Joseph Pogue

THE, prices of crude petroleum and its derivatives have shown an upward trend from 1915 to 1920, and a downward trend from 1920 to 1923, see Table 1. Over the former period, oil prices were dominated by the rapidly increasing demands and inflation incident to the war and its aftermath, while over the latter period oil prices were influenced at the outset by deflation and then by the conditions of overproduction that have characterized the past three years. The purpose of this paper is to analyze the broader features of the more recent price movements in the petroleum industry and to relate these features to basic economic conditions in the industry. INDEX NUMBERS OF OIL PRICES The analysis and comparison of price movements may be facilitated by converting actual prices into relative prices, or index numbers, with 1913 taken as a base of 100. In this way, the various price groups are expressed as percentages of the 1913 prices and may thus be readily compared with one another or with the average prices of other commodities similarly expressed. Table 1 gives the index numbers representing the average prices of crude petroleum, gasoline, kerosene, fuel oil, lubricating oils, and all commodities. The last named is the index of all commodities as published by the U. S. Bureau of Labor Statistics and .is widely accepted .as the official measure of the general price level. The index numbers of oil prices were calculated by the writer from weekly quotations published in trade journals.

Jan 3, 1924

By R. H. Heinen

Introduction Drilling is the initial operating step In open pit mining. It goes hand-in-hand with the blasting operations to ensure adequately broken material for the excavation equipment employed. The drilling effectiveness is highly dependent on the quality of the drill evaluation. This discussion will center on the parameters that are needed to evaluate drill requirements for a new mine The procedure that is generated can, however, be used to evaluate whether to expand existing operations and replace existing equipment. Methods of breaking ground, other than blasthole drilling and blasting, such as ripping, will not be discussed. The importance of correct drill evaluation extends to the other facets of open pit mining. Inadequate fragmentation, the direct result of poor drilling and blasting techniques, results in oversized, hard digging for the excavating equipment. The result is higher secondary blasting costs, reduced excavation efficiencies, higher excavation costs, higher road repair costs, and higher haulage equipment costs. The main objective of evaluating drill fleet requirements, therefore, is to determine the equipment needed to minimize the operational constraints, caused by blasthole drilling, on other facets of open pit mining at the lowest cash flow costs.

Jan 1, 1979

By Frank H. Skelding

Still the world's largest producer, consumer and importer/exporter of minerals, the United States has, in recent years, become more and more aware of the many diverse forces that increasingly affect its ability to maintain free access to and trade in minerals, both domestically and abroad. The nation's growing dependence upon foreign sources of minerals in the face of mounting competition is causing many changes, not only in the mineral industries, but in national attitudes and policies as well. This paper examines the position of the United States in the world mineral economy relative to the significant trends that have and are developing. It attempts to define and evaluate the major present and future impact of these trends and to anticipate the probable effects upon the U.S. and its mineral economy.

Jan 1, 1976

By A. Lee Barrett

The Maintenance Committee of the Coal Division of the American Institute of Mining and Metallurgical Engineers is presenting with this report the first of a series of cost comparisons which it plans to present the Institute. The plan is to assemble maintenance cost on all equipment connected with mechanical operations at the face of coal mines, to arrange these costs by districts, to make comparisons between districts, and within districts. This particular report covers data with respect to mobile loading machines, including both "on-track" and "off-track" equipment. It is anticipated—in fact, considerable data have already been accumulated—that next year complete maintenance costs by districts can he presented for complete loading units, including the various classes and combinations of on-track and off-track equipment. Data have also been collected with respect to some phases of maintenance methods and certain recommendations of the committee are included dealing with maintenance problems. In the assembly of these data more than 120 questionnaires were sent to operating companies throughout the United States. At the time the report was written 33 questionnaires had been returned with completed information and an additional group of companies had written that the information requested was not at present available but that they hoped to have such information available in the not far distant future. The replies as

Jan 1, 1947

By S. F. Willey

Difficulties encountered in justifying replacements for overage mobile mine equipment at the Gay mine are common to most mining operations. More critical management reviews, resulting from ever rising capital expenses, increased such difficulties. These increased difficulties are especially apparent to those who are primarily operators and are not statisticians, mathematicians or computer men. The Gay mine is located 17 mi east of the town of Fort Hall in southern Idaho. This open pit operation annually supplies the J. R. Simplot Co. and the FMC Corp. with 1.5-2.0 million tons of phosphate ore. Stripping ratios average approximately three bank cubic yards of waste per ton of ore mined. The mobile mine equipment fleet consists of ten 24-cu yd scrapers; twenty-one 30-50-ton end-dump trucks; four 3%-4%- cu yd shovels; fifteen dozers in the D-8 and D-9 classes; and three road patrols. Equipment replacement is based on the results of evaluations made on individual units.

Jan 9, 1972

By Neil H. Cole

Cost and price inflation and financial gearing through loans are characteristic of modern resources projects. Conventional discounted cash flow and 1P.R analyses, in real terms, and without financing, have inadequacies which can yield misleading results. The degree of improvement in value for project equity owners is limited to the value of the additional tax benefit accorded through the financing instrument used. Debt financing may be low in price and value, but its priority means that the equity owners assume a higher risk, thereby increasing the cost, or price, of their capital. The cost of equity capital, or investment hurdle rate, is related to the Capital Asset Pricing Model. Distortions do occur, with inflation, due to depreciation effects, which can cause the adoption of misleading project rate of return or hurdle rate criteria. For investment decisions, the greatest accuracy possible in forecasting is essential, especially for inflation rates,

Jan 1, 1985

By R. E. Smallman, J. C. Terry

J. C. Terry and R. E. Smallman (Llniuersity of Birmingham, England)—In a recent publication53 Wood and Westbrook have reported the results of an investigation of the tensile behavior of fl-phase AgMg alloys. These results agree in broad outline, but differ in the details, with those obtained in the above laboratory and, consequently, some discussion of their paper would seem appropriate. In our experiments, tests were carried out on extruded wires, 2 mm diam, in a hard-beam tensile machine, and while an oil bath was used for the tests up to 150°C, above this temperature the oil bath gave rise to serious contamination of the specimens and hence tests above 150°C were made in vacuo. This procedure is different to that adopted by Wood and Westbrook. The ß-phase alloys exhibit differences in mechanical behavior when they are tested in different temperature ranges. In agreement with Wood and Westbrook, three characteristic ranges are observed which may be classified as low, intermediate, and high temperatures, respectively. Our experiments show that in the low-temperature region, the shape of the stress-strain curves is similar to that reported. However, in addition, it is observed that the temperature at which the low-temperature region ends is markedly dependent on strain rate, and increase with increasing strain rate as shown in Fig. 18. The temperature at which a transition from the low to the intermediate temperature takes place is about 0.4 to 0.45 of the absolute melting point, Tm. This transition temperature coincides with that at

Jan 1, 1963

By Donald W. Gentry, John F. Abel

This paper presents some of the results of a rock mechanics instrumentation program designed for, and implemented at, longwall panel 4N at the York Canyon Mine near Raton, New Mexico. The objective of this particular instrumentation program was to determine the response of the rock mass to longwall mining of a thick coal seam utilizing shield-type supports. Measurements were made in the rock along the ground surface, above the coal seam, in the coal seam, and immediately below the coal seam. Longwall test panel 4N had a total developed length of 762 m (2500 ft) and a face width of 168 m (550 ft), Fig. 1. The seam mining height in the panel area was approximately 3 m (10 ft). The average depth of overburden above the panel is 107 m (350 ft) although it ranges from 73-134 m (240-440 ft). Roof support at the face was provided by 116 Hemscheidt 320 HSL shields. These shield-type supports weigh 11.4 metric tons each.

Jan 3, 1978

By E. J. Parkins, H. L. Shergold

The paper is divided into two parts. The first part describes an investigation of the effect of temperature on the conditioning and flotation of an ilmenite ore with a 1:l oleic acid-fuel oil mixture as collector. During conditioning the pulp underwent characteristic changes of flocculation, deflocculation and dispersion which were monitored by measuring the power consumption of the conditioner motor. Optimum flotation results were obtained at the end of the deflocculation period. High ilmenite recoveries were obtained at high temperatures and high concentrate grades at low temperatures. The second part of the paper describes a study of the effect of temperature on the adsorption of oleic acid at the ilmenite/water interface. At high adsorption densities it was chemical and exothermic. Contact angles showed that the hydrophobicity of the collector-coated minerals increased with an increase in temperature.

Jan 1, 1976

By Carle Hayward

THE effect of copper on steel has been studied by numerous investigators. Before modern testing methods had been developed, blacksmiths noted red shortness in iron, the cause for which was ascribed to the presence of copper. Numerous papers have been published on the corrosion of steels containing various amounts of copper, and a few writers have discussed the effect of copper on the mechanical properties of steel. The purpose of the investigation described in the following paper was to obtain additional data on the mechanical properties of medium-carbon steel containing small quantities of copper. Among those who have published results of mechanical tests on copper steels are Ball,1 who states that copper increases the tensile strength and 'hardness but lowers the elongation. Stead2 states that copper steels closely resemble nickel steels containing equivalent percentages of nickel,, as regards tensile strength, resistance to shock, corrosion and hardness. Wigham 5 found that copper in small amounts had no injurious effect on steel. Breuil4 found that with 1 per cent. carbon, copper lessened the brittleness of steel and in low-carbon steel it increased the tensile strength and lowered the ductility slightly. H. H. Campbell 5 states that copper up to 0.25 per cent. slightly raises the elastic limit, elongation and reduction of area.

Jan 1, 1918

By H. C. Fiedler

THE development of the cube-on-edge secondary re-crystallization texture in Si-Fe strip depends upon the ability of inclusions to restrain normal grain growth. This ability is determined by the number and size of inclusions, which, for a given composition, is controlled by the thermal history of the material during the prior processing.' It has been shown2 that increasing the silicon content decreases the solubility of sulfur, and it is the purpose of this note to show the consequences of this decreased solubility for secondary recrystallization. Heats were made as previously described and cast into graphite molds.' The compositions are shown in Table I. Slabs 1 in. thick were cut from the ingots and either hot-rolled from 1000°C in the as-cast condition or after one of the heat treatments described later. The processing to the final gage of 12 mils followed the previous procedure.' To avoid cracking, the 5.2 pct Si alloy was cold-rolled at 150" to 200°C rather than at room temperature. The percent cube-on-edge texture developed by isothermal heat treatments was determined by dividing the maximum torque measured on disk sam-

Jan 1, 1968

By D. B. Crouch, D. A. Poulter

The engineering and metallurgical assessment of the McLaughlin Project ore body concluded that an open-pit mine and cyanide leach mill process would be feasible, producing both waste rock and residual mill tailings. As a part of the planning and permitting process, site selection studies were conducted for the tailings and waste rock disposal. The site selection process began with a regional identification of potential disposal sites and proceeded through 1) regional screening, 2) elimination of sites with obvious fatal flaws, 3) qualitative ranking of site evaluation criteria, 4) quantitative ranking of sites, 5) field investigation, 6) evaluations of field data, and 7) selection of preferred sites. Based on this approach of site rankings and field evaluations, tailings and waste rock disposal sites were selected and recommended for the preliminary design phase of the permitting and project development process. The site selection study provided the documentation necessary to justify the use of these sites for waste disposal and enabled Homestake Mining Co. to anticipate and integrate environmental concerns with agency requirements into the planning process.

Jan 1, 1986

By Tracy Jarrett

In 14-karat gold alloys, as in 10-karat gold alloys,3 the addition of such metals as zinc, nickel, copper and silver produces a wide range of physical and chemical proper-ties such as color, hardness, corrosion resist-ance and melting points. These important factors made gold alloys desirable in the optical work and for jewelry. In 14-karat gold alloys, as well as in 10-karat or 12-karat, it is possible to have two golds of the same color, one of which will corrode more than the other, although it may be harder. Some of these alloys have been investigated by F. E. Carter,1 E. M. Wise,5 and L. Sterner Rainer.4 In this group of alloys the gold content of 58.3 per cent (14-karat) was held constant, while the copper varied from 36 to 24 per cent. The balance of the alloy consisted of one, two, or three of the metals silver, zinc, and nickel. All the alloys were melted in an induction furnace and cast into an ingot that meas-ured 3 by 1/4 by 3/4 in. The method of determining the melting points, color deter-minations and acid test have been discussed in previous papers by the author.2,3 It is necessary to use small test bars (Fig. r). The tensile bars were annealed at 1300°F. for 20 min. and then air-cooled. There being a very marked drop when the yield point was reached, "the drop of the beam" method was used in determining the yield point.

Jan 1, 1940

Prior to any detailed discussion, I'd like to say that Dr. Aplan has made direct hits on two important considerations: 1) The most demanding need in Fine Coal research is to develop improved methods of sulfur reduction. 2) The areas of particle (impurity) liberation and froth flotation hold real near-term promise as techniques for improved sulfur removal. Digressing for a moment, I thin kwe can all remember the time when the biggest problem facing coal research was simply defined - "No money!" In the mid 70's we suddenly found ourselves dealing with a product worth five to seven times the value it carried in the mid60's. All of a sudden, we're talking about a high-profile, high- value commodity. The coal industry still hasn't made the complete psychological adjustment - especially in the operating areas (prep plants included). We have a valuable material at hand which is, in' many cases still being processed as though it were a two or three dollar per ton item. Simply put, I think that while the industry has made some major strides during this transition, a stronger commitment of attitude (and finances) needs to be made toward deeper definition of beneficiation work. Back to specifics - Dr. Aplan has really highlighted three areas where strong research efforts are needed. 1) Liberation processes - not limited to mechanical comminution - must be more fully studied.The industry certainly needs a better handle on value returned (improved ability to beneficiate) for dollars spent on improved liberation. 2) Flotation processes probably hold the most promise for near- term improvement in fine coal beneficiation technology. Dr. Aplan’s.

Jan 1, 1979

By H. F. Korman, M. C. C. Mow, P. K. Dai

INTRODUCTION Detonations of high explosives in soil and rock have been used frequently in civil engineering applications. Of particular interest in recent years has been the development of test methods to simulate the desired blast and shock environments for the testing of protective structures. The United States Air Force, in particular, the Air Force Weapons Laboratory, in conjunction with the Defense Atomic Support Agency, has in recent years, developed special technology for simulation testing of protective structures in soil and rock media. Such a technology, although initially developed for military applications, is rapidly finding its way into civil applications. One of the major problems in the design of the simulation test is the correct prediction of ground motion induced by the detonation of high explosives. This paper presents a useful prediction method which is developed specifically for ground motion in rock that is induced by the detonation of a buried planar array of explosive columns (See Figure 1). The technique of simulating shock environment using such an array is called the Direct Induced High Explosive Simulation Tech- nique (DIHEST). Normally, each shot hole may contain canisters of ammonium nitrate positioned at various depths, or a slurry explosive with detonators positioned along its length (See Figure 1). The depth and width of the array, the spacing of shot holes, the spacing of detonators, the degree of containment, and the charge weight are the variables which govern the induced ground motion

Jan 1, 1971

By Byron E. Eldred

Generally speaking, the practical study of combustion has been made mainly from the stand-point of the steam engineer. This narrow view-point has left open a large field for scientific research on the application of combustion in other arts, where the conditions of heat-utilization are widely different from those presented in the steam-generator. The great economic importance of the boiler and the ease of measuring its performance, together with the comparative uniformity of conditions in the steam-generator, is, probably, quite largely responsible for the practical neglect of the study of the use of fuels in other arts save only on the basis of their thermal value. yet these other arts show quite plainly that a thermal-value basis alone is not sufficient. For example, in burning lime, under ordinary conditions of firing, a cord of wood will do as much work as a ton of coal, though the latter affords more than twice the number of heat-units. Similar results are evidenced in burning brick, in the roasting of certain ores, in reheating billets, and in many other, arts where heat is to be applied over extended areas to fragmental masses of more or less refractory materials. In these arts much is to be gained by a

Jan 1, 1911

By W. A. Oates, J. S. Blakemore, E. O. Hall

AS part of an investigation into the effect of hydrogen on the serrated yielding of Ni-Cu alloys,' it was necessary to determine the solubility of hydrogen in the alloys of interest. With the exception of the work by Fukusima and Mitui2 who investigated the solubility of hydrogen in solid Ni-Cu alloys at 20 wt pct intervals at 1050°, 700°, and 350°C, the information in the literature is limited.3-10 Alloys were prepared from deoxidized Analar Copper and Mond Nickel pellets.' Wire samples were hydrogenated at 7.8 atm in an autoclave consisting of 5 ft of thick-walled Inconel 600 tube with a resistance furnace around the middle portion. The top end, at room temperature, was fitted with a safety valve, a calibrated pressure gage, and a sample inlet, while the bottom end, again at room temperature, was filled with water. After reaching equilibrium samples were quenched by dropping from the high-temperature region of the autoclave into water. They were then quickly transferred to liquid nitrogen where they were stored until analyzed for hydrogen using an Exhalograph.11 The results, which are shown in Fig. 1, represent the mean of two separate determinations on each sample. Because of the lower level of hydrogen at the high copper end of the series, the results here are of poor precision using this method. Fortunately, the results of Himmler9 using the Sieverts technique are available for these copper-rich alloys (>80 at. pct Cu)

Jan 1, 1969