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By Hamid Maleki

A geotechnical monitoring program has been implemented at Energy West Mining Company for enhancing site-specific evaluation of longwall stress conditions. This program consists of underground measurements at five locations in two neighboring mining districts located in the Hiawatha and Blind Canyon Coal Seams under moderate to deep cover. Within the last five years, additional measurements, including data on recorded seismic events and face conditions, have been incorporated into the data collection program together with detailed geologic mapping of longwall gateroads. In conjunction with the measurement program, the authors have completed detailed boundary-element stress analyses of the mine plans. Models have been calibrated using the data from in-mine instrumentations and then routinely used for evaluation of mine plans at depths approaching 2,600-ft. The work has improved our understanding of load transfer, seismicity and yield pillar performance. It has identified areas of potential increased stress levels at certain longwall face positions and provided guidance to measures that could be considered to mitigate the potential for these increased stress levels.

Jan 1, 2009

The Maddingley brown coal seam at Bacchus Marsh, where mined and bored, tends on the whole to a higher content of volatile matter than the Latrobe Valley brown coals, and this masks the presence of lignitic or earthy coal bands in the bore core analyses. Visits to the Lucifer Open Cut, at Bacchus Marsh, during 1948, revealed, however, a banded condition in the coal seam, as shown in Fig. 1. This banding showed in a face that had been exposed for a considerable period of time, permitting partial drying out and oxidation of the surface coal. The bands consist of different coal types, ,comparable with those found in the Yallournand Latrobe brown coal seams(l).The' light coloured bands in Fig. 1 consist of a buff to light-brown earthy coal of low specific gravity, that closely resembles the pollen coal, that occurs, as similar thin bands in the Yallourn and Latrobe seams. The 40 ft. of coal above the uppermost of these light coloured bands dries out on exposure to a black, closely cracked surface, composed of small dice-like fragments of a lustrous vitrain-like substance, and in every respect resembles the lignitic coal bands of the Yallourn and Latrobe seams.The coal between and below the light-coloured bands develops fewer and more widely spaced shrinkage cracks on drying out, and remains brown in colour and earthy in appearance, resembling the earthy coal of the Yallourn and Latrobe seams.Representative samples were cut of these coals, taking care to exclude surface coal, and analyses were made of them by the Metropolitan Gas Company, through the kindness of Dr. R. S. Andrews, Chief Chemist to the Company...

Jan 1, 1948

C. E. Dewey, Georgetown, Colo. (communication to the Secretary) : In his remarks on crushing-machinery, Mr. Douglas says (Twins., xxii., p. 322): "To insure a smaller and more uniform size of particles in the crushed material, the Dodge crusher still communicates motion to the upper extremity of tile movable jaw, which oscillates on fixed pivots projecting from its lower extremity!' The notion that, in order to obtain a fine and uniform product from a rock-breaker, the movable jaw must be pivoted at its lower extremity, seems to obtain generally among mill-men, as well as among manufacturers of machinery. My experience with machines of both types does not confirm this belief. It is true that, to obtain a uniformly fine product from a jaw-crusher, the stroke at the lower extremity of the crushing-surface must be short; but that the movement at that end must be less than at the other or receiving-end is, I think, an erroneous assumption. Figs. 1 and 2 are intended to illustrate the two types of machine. It is found in practice that the capacity and the nature of the product of either machine, as usually constructed, are governed by the opening, C D, and the length of stroke of the movable jaw at D. This being the case, machines of either type, of the same width of crushing-surface, running at the same speed, and having the same adjustment as to opening and stroke at D, should give, when fed

Jan 1, 1895

By H. C. Doepken

Wrought Hadfield steel was tested in axial tension at from 100° to —196°C, to determine flow and fracture stresses as well as conventional properties. Ductility and related properties, such as fracture stress, decreased continuously with temperature. Peculiarities during straining indicated possible martensite formation or mechanical twinning. THE mechanical properties of austenitic manganese steel have been summarized by Avery and Day,' including the low temperature tensile properties reported by Hadfield and coworkers2,3 " These data show the material to be brittle at both liquid oxygen and liquid 'hydrogen temperatures. Avery and Day report considerable ductility measured by Charpy V-notch tests at —100°F (-73°C). Since the review of low temperature properties by Seigle and Brick' show face-centered cubic structures, other than Hadfield steel, to be ductile at low temperatures, it was felt that a study of tensile properties, between the reported intervals, should show whether the decrease in ductility was a gradual decline or an abrupt drop beginning at some intermediate point. X-ray examinations were made in an attempt to shed further light on the mechanism of work hardening of austenitic manganese steel. The presence of a magnetic constituent has been found by Hall" and by Avery, Homerberg, and Cook." Krivobok7 demonstrated the growth of magnetic constituents on reheating cold-worked specimens. Hadfield2,3 ' and Goss found no a iron. The steel from which the specimens were taken was commercial hot rolled % in. diam rod of electric furnace steel. The ladle analysis was as follows: C, 1.40 pct: Mn, 12.11; P, 0.060; S, 0.012; Si, 0.120; Ni, 0.080; and Cr, 0.090. Fifteen specimens, 6 in. long, were cut from a

Jan 1, 1953

By Robert Perlman

El presente texto señala las nuevas técnicas cuantitativas que pronostican los términos cortos y largos de los precios de los metales. Estos métodos permiten la construcción de un modelo de comportamiento que comprende matemáticamente los diferentes tipos de sistemas económicos. Un modelo económico consiste en un sistema de ecuaciones que indican cómo trabajan los mercados. Para ello, los ingenieros de diseño aplican esta clase de construcción de modelo a sistemas fsicos como puentes, refinerías. La diferencia entre este tipo de modelo y un modelo económico es que la relación entre las variables con las que el ingeniero trabaja pueden ser complejas, pero están basadas en conocidas leyes físicas exactas, mientras que el economista usualmente tiene que identificar las relaciones por sí mismo y éstas nunca son exactas.

May 1, 1973

By F. Hulsmeir

The increase in drilling activities in Venezuela noted during the latter half of 1932 continued, and 132 wells were completed in 1933 as compared to only 60 completed during 1932. Notwithstanding these new wells, 114 of which were producers, and also the appreciable increase in artificial lifting installations during the year, Venezuelan production was maintained at only a slightly higher level than in 1932, amounting to 120,356,000 bbl. in 1933 as compared to 118,167,000 bbl. in 1932. However, at the end of the year the daily average production of 358,-860 bbl. was 16 per cent higher than that at the end of 1932. Exports from Venezuela recorded an increase of approximately 4 per cent, totaling

Jan 1, 1934

By S. Inaba, K. Taguchi, T. Uenaka, I. Mizuguchi, K. Umeji, H. Isako

At Kobe Steel Ltd., various improvements in pellet quality have been carried out since beginning lime-fluxed pellet production. Especially, dolomite-fluxed pellets, developed in 1975, have superior high temperature properties. With this improvement, successful BF performance has been achieved. But, in order to achieve more successful BF performance, improvements of physical properties such as the shape factor, reposed angle, and the bulk density are desired. Now, crushed pellets have been developed for the improvement of those characters. The test operation with these new pellets in Kakogawa No. 2 BF was carried out with successful results. This report describes the development of crushed pellets and their use in BF.

Jan 1, 1986

By William R. Taylor

This paper reviews the mining and related legislation history of in situ uranium mining in southwest Texas with emphasis on the last five years. It also reviews the current regulatory process and some of the more critical concerns and concepts relative to containment and restoration of in situ mines.

Jan 1, 1979

ALEXANDER BURRELL Alexander Burrell, general manager of the Furnace Creek Oxide Copper Mining Co., and' a member of the Institute for 20 years, died suddenly at the Argo mine on Feb. 13, 1917. Mr. Burrell was one of the best known mining men in Montana. He was horn at Edinburgh, Scotland, Jan. 14, 1851, and came to Chicago with his parents in 1856. His father, who was a coppersmith, died soon after their arrival, and the ,son had few opportunities to gain an education in school, but was a natural student and was possessed of a liberal education acquired through self-teaching and through his constant reading and studying, particularly along scientific lines. It was this technical knowledge both of mining, and business, as well as his experience in the practical side of mining and his ability as an executive that won for him a high place in mining circles in Montana. As a very young man he worked as a miner in Illinois and later became an operator of a coal property. Subsequently he engaged

Jan 4, 1917

By Jorge Munoz Reyes

There was no development work in Bolivia during the year 1935, and oil was produced only to meet the needs of the army and of the local market. The refineries in the districts of Camiri and Sanandita treated 25,978,737 liters (163,388 bbl.) of crude oil, which yielded 4058 bbl. of aviation gasoline (Camiri only), 7381 bbl. of gasoline, 718 bbl. of kerosene (Camiri only) and 83,105 bbl. of fuel oil.

Jan 1, 1936

By Jorge Munoz Reyes

There was no development work in Bolivia during the year 1935, and oil was produced only to meet the needs of the army and of the local market. The refineries in the districts of Camiri and Sanandita treated 25,978,737 liters (163,388 bbl.) of crude oil, which yielded 4058 bbl. of aviation gasoline (Camiri only), 7381 bbl. of gasoline, 718 bbl. of kerosene (Camiri only) and 83,105 bbl. of fuel oil.

Jan 1, 1936

By C. R. Pelley

This paper describes the analytical characteristics of Western subbituminous coal and the manner in which these characteristics apply to their use in a utility-sized steam generator. It compares these characteristics with those of typical Midwestern coal and Eastern bituminous coal. The paper also reviews in detail the design considerations that must receive attention when various blends of these three coals, or any combinations thereof, are planned to be used. This research paper describes variations in analytical and utilization characteristics when coals from different origins are blended in order to achieve a predetermined sulfur content for the purpose of predicting sulfur oxides emissions as they affect environmental regulations and the resulting alterations in utilization characteristics such blending would cause, and how such blends of coal would affect a utility-sized steam generator.

Jan 1, 1979

By R. G. Jurd

This paper considers the introduction of large-scale longwall mining into South African coal mining, instead of the conventional mechanized bord-and-plllar mining that is widely practised at present. The two methods are compared, and longwall mining is found to have the advantage in several respects in some seams. The most cogent reasons for the introduction of the longwall method In some seams are associated with safety strata control and increased labour costs.

Jan 1, 1978

By Louis L. Sirois, Kwang S. Moon

The flotation mechanisms of various flotation machines are briefly reviewed. The counter current column flotation mechanism is described in more detail. The merits of counter current column flotation include; improved metallurgical performance in terms of grade and recovery, effective cleaning action in the long cleaning zone with a blanket of fresh water, smaller floor space required due to the vertical configuration of a flotation column, low capital, operational, and maintenance costs due to the absence of moving parts and finally, easier flotation control due to the simplified circuit. The results of column flotation studies on various minerals and coal at CANMET are discussed. Some of the industrial experiences with the Canadian flotation column on various sulphides, oxides and coal are also presented.

Jan 1, 1988

By A. Sainato, S. J. Kravits, G. L. Finfinger

This Bureau of Mines report describes and compares the procedures, capital investments, and operating costs of rotary and in-hole motor drilling techniques used to drain methane gas from the Pittsburgh Coal- bed in an underground mine located in southwestern Pennsylvania. A timestudy was conducted during the drilling of each of two boreholes, and the data were collated to serve as a base for comparing drilling procedures and operating costs. Findings indicate that drilling with an in-hole motor offers four advantages over rotary drilling; namely, an increase in drilling productivity, fewer worker-hours required, ease of maintaining vertical and horizontal bit trajectory, and less expensive drilling cost per foot of borehole.

Jan 1, 1985

Buoyant levels of world economic growth and recovery in intensity of metals usage suggest that demand for minerals will remain relatively strong into the 1990's. Supply constraints, low stock to use ratios, financial and political factors imply lower elasticities of supply for minerals in the future. The outlook for minerals and metals prices from a pro-ducers viewpoint is, accordingly, promising.The recent recovery in world minerals prices, following strong growth in the world economy over the last few years, makes it appropriate to consider the structural forces at work in the formation of world demand and supply of minerals. This paper will review past trends and consider some of the main economic issues facing the mining industry in the 1990's.

Jan 1, 1990

By Roy E. Dickerson

No important new developments took place during the year 1937 in Cuba. Estimated figures are as follows: Bacuranao field, 100 bbl. per day petroleum; Motembo and Vesubio areas, 120 bbl. per day natural gasoline.

Jan 1, 1938

By Jr. W. L . Phillips

The deformation and fracture characteristics of lithium-fluoride single crystals stressed in compression at room temperature have been studied. In as-cleaved specimens the stress-strain curves were variable; two types of {110} fractures were observed in the vicinity of kink bands. The stress-strain curves of annealed crystals were reproducible; {100} cracks formed which propagated along the (100) and (110) planes. The deformation and fracture characteristics were affected by quenching and X-ray irradiation. STUDY of the mechanical behavior of nonmetallic materials has received considerable impetus in recent years because of the need to overcome the problem of brittleness before the refractory properties of nonmetallics can be fully exploited. Ionic crystals provide a convenient and simplified starting point from which to study the deformation and fracture processes in nonmetallic materials. Early investigations of the mechanical behavior of non-metals were restricted largely to determinations of the crystallographic indices of the cleavage and fracture planes and the glide and twinning elements. Until recently, only occasional systematic studies of the deformation characteristics of non-metals have been made; and investigations of the forces necessary to initiate plastic deformation and the factors which affect the flow characteristics have been restricted largely to studies of sodium chloride'-7 , magnesium oxides-l3 and lithium fluoride. 14-22 Fracture studies on alkali halide and metal oxide single crystals have been limited despite the fact that these materials have a number of advantages for fracture studies. Because they are transparent, the cracks which form can be viewed in three dimensions instead of in two dimensions as in metals. Also, they exhibit stress birefringence under polarized illumination, which enables the internal stress pattern and, therefore, the distribution of dislocations to be examined in the vicinity of the fracture. Early workers1-4 have shown that ionic crystals with a cubic structure fracture in tension along the (100) plane normal to the applied stress. These fractures were brittle at room temperature and propagated very rapidly across the cross section of the crystal. More recently, Stokes, Johnston, and Lil0 have studied crack formation in compressed magnesium-oxide single crystals. They found that the cracks, which were observed after about 3 pct strain, formed in the region of a kink band and lay on conjugate (110) slip planes instead of the usual(100) cleavage plane. Two different types of cracks were noted: stroh23 and secondary. The Stroh cracks did not exist merely on the surface but extended through the specimen in the form of tiny slits. A secondary

Jan 1, 1962

By Ambarish Ghosh, Subhaprasad Chakraborty

"Construction of basement floors has become necessary to meet the requirement of parking in office and residential complexes and in hospitals for radiotherapy treatment. Important projects coming up in Kolkata are mostly in closer proximity of residential buildings, office buildings and historical monuments. Sheet piling is mostly used as temporary shoring system during construction. Deep excavation in urban environment creates great problem related to construction induced vibration due to driving of sheet piles for basement, pile driving etc. which raises the chances of damage of adjacent buildings and nearby structures. Vibratory sheet-pile driving is the most common method of sheet pile installation. The knowledge of induced vibration due to this phenomenon is still very deficient. This paper presents the analysis of measured vibration data collected from different sites of Kolkata with varying soil profile. Typical two case studies of sheet pile and pile driving has been presented and the vibration values are analysed. The responses of the vibration are reported in terms of peak particle velocities (PPV). To evaluate the effects of vibration due to pile driving two aspects have been considered: the effect of the energy entering the ground from the pile and the effect of the soil condition.INTRODUCTIONIn urban areas infrastructure development projects are mainly located adjacent to existing structures like residential buildings, offices and historical structures. The construction work of such project influences the surrounding environment as well as human perception (Wiss 1981). During the construction of basement for residential complexes and hospitals sheet piling is mostly used as temporary shoring system or as to support the earth mass. The vibration induced due to driving of piles and sheet piles have been presented herein. Deep excavation projects close to existing structures increase the concern of environmental impact. For this reason the vibration assessment and prediction has become a subject of great interest. It is important to develop a site specific model for predicting the ground vibration resulting from pile and sheet pile driving at the construction sites. The developed model gives the efficacy to guide the engineer to select the construction methodology ensuring the safety of the surrounding structure. The model developed here is site specific and the parameters that has been used are dependent on the soil condition and the energy source."

Jan 1, 2015

THE iron and steel industry spent $1,170,000,000 in 1952 for improvements and expansion, with an accompanying rise of 9 million net tons in capacity to 117.5 million tons of ingots and steel for castings. More than $4,600,000,000 has been invested in the seven years following World War 11. An average of $1260 has been laid out every minute during those seven years for an increase in capacity of 25.6 million tons.

Jan 3, 1953