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By S. Maurigiannakis

In an effort to promote sustainability in the construction industry, the natural decorative stones that cover large external areas of buildings may be replaced with artificial stones. In this paper the physical and mechanical properties of artificial decorative stones are presented and are critically compared with corresponding natural stones. To test suitability for various applications, artificial stone specimens were subjected to weathering testing (freezing-thaw cycles in a climatic chamber). Mechanical characterization of these specimens was based on uniaxial compressive testing as well as non-destructive ultrasonic testing. Preliminary results show that artificial stones can replace natural stones, thus creating a sustainable development option for the construction industry.

Jan 1, 2003

By B. B. Zavoico

During 1936 the Russian oil industry made very satisfactory progress and, while not all difficulties of organization have been ironed out, the country is now assured of a supply of petroleum products in sufficient quantities and of quality demanded by modern motor equipment. The year 1937 promises to better by a wide margin the good showing of 1936. The statistics given in this paper for the first time take into consideration the varying gravities of crude oils of the several Russian oil fields instead of using a flat conversion factor of 7 bbl. per metric ton. It was found from the detailed study that the generally used average conversion factor should be increased from 7 to 7.25 bbl. per metric ton, the figure varying, of course, with the gravity of oil in the individual fields. Crude-oil production during 1936 is estimated at 201,500,000 bbl. as compared with 182,970,000 bbl. produced in 1935, an increase of 9.4 per cent. The greatest increase was again recorded in the Baku district, which increased its production by 10.9 per cent, from 141,257,000 bbl. in 1935 to 158,300,000 in 1936. Grozny district maintained its production at a level of about 23,000,000 bbl., but its old fields continued to decline and production was sustained by the development of newer fields. A great advance was made in drilling speeds and the total footage in 1936 reached 6,694,200 ft. as compared with 4,926,600 ft. drilled in 1935, an increase of 26.4 per cent. In older deep fields, producers were being completed at over 8000 ft.—a great depth for Russian drillers but two years ago. Several major discoveries were made in 1936. Northeast Caucasus.—Izberbash, east from Grozny and on the Caspian Sea, was the outstanding discovery, the initial production of the discovery well being around 3000 bbl. per day from about 5000 ft. The importance of the field is due to the large area of the structure, half of which, however, is under the sea, and also to its strategic location on the shores of the Caspian and near a trunk pipe line to the Grozny refining center. An active development program is being pursued in Izberbash and its 1937 production quota is set at 7,500,000 bbl. Achi-Su field, near Izberbash, also discovered during 1936, while not as prolific as Izberbash, is thought to cover a very large area and the small

Jan 1, 1937

By R. M. S. B. Horta, W. T. Roberts, D. V. Wilson

Evaluation of results obtained by the Harris method for inverse pole figures is discussed. Two existing analyses and a new approach are compared. In the most frequently used analysis, different reflections are accorded equal weight. A second method involves area-weighting of reflections, mainly to take account of nonuniformity of Pole distribution. In the new method, reflections are weighted according to their multiplicity factors. Intensity ratios obtained from a sample of steel sheet by the three methods are compared. INVERSE pole figures offer a convenient method of depicting the proportions of material with various orientations referred to a unique specimen axis. The technique was first applied to fiber textures, but it is now frequently used as a description of texture in sheet metal, the unique axis in this case usually being the sheet normal. The Harris method' for the determination of inverse pole figures has the great merit of simplicity. It suffers certain intrinsic limitations, but provided that these are borne in mind, the results allow useful conclusions to be drawn regarding the effects of texture components on certain mechanical properties. Much thought has been given to alternative methods of texture description, aimed at eliminating the ambiguity in the simpler methods.2"6 Refinements in the method of description are obtained at the price of increasing complexity, and it seems clear that a simple method, such as that of Harris, will continue to find application. The original derivation by Harris1 has been corrected by Morris7 and later by Mueller, Chernock, and Beck.2 Since the latter reference is more accessible, it is referred to more frequently than the work of Morris. Most users of the inverse pole figure method present their results on the basis of the treatment by Mueller et al., and it is the purpose of the present communication to comment on this treatment and to suggest a simple modification to the method of presentation which enhances the meaningfulness of the results. It will be convenient first to summarize the Mueller analysis as follows: The intensity Ihkl of a hkl reflection from a textured specimen is: Ihkl=CI0AL\Fhkl\2NhklPhkl [1] where C is a constant for a given sample I, is the intensity of the incident beam A is an absorption factor. With usual diffrac-tometer geometry and a flat specimen, A is inversely proportional to the density of the specimen. L is the Lorenz polarization factor Fhkl is the structure factor for the hkl reflection Nhkl is the multiplicity factor phkl is the fraction of crystals in the polycrystal-line aggregate with any particular (nkl) plane parallel to the surface. The corresponding equation for a specimen with randomly oriented grains is lR,hkl=CRl°ARL\fnkl\2Nnklk [2] the subscripts R indicating the factors that are different for the random sample, which will, in general, have a density different from that of the textured one. The intensity ratio is hkl , c A Phkl [3] IR,hkl CR AR PR The constants are eliminated by summing over all the measured reflections ^iRMi °R AR PR ljPkkl and from Eqs. [3] and [4] T IR,hkl The only unknown in Eq. [5] is Yj phkl and before this can be evaluated, it is necessary to adopt some form of normalizing procedure. Mueller et al. assume that when a large number, n, of reflections is used, the average value of p as defined by Eq. [6] below will be unity ? = £j**l3l [6] and the final result of their analysis follows: hkl Pkkl = i I&Jf~ [7] ±y* Ihkl ^ in,hki The normalizing procedure used by Mueller et al. involves an unrealistic assumption since it gives equal weight to each of the hkl reflections. Other normalizing procedures can now be examined with a view to selecting a more appropriate one. For an infinite number of reflections, the function p can be averaged over a continuous range of orientations covering the complete solid angle 4p by the integral relation: p =1 jp(a)dQ = l [8] This is the only exact procedure, but in practice a

Jan 1, 1970

By J. K. Horbaczewski

The reclamation of an open dragline pit (Pond A3P-2) at the Gibbons Creek lignite mine in east-central Texas required neutralization of acid mine pit water. At the start of treatment with hydrated lime (Ca(OH)2) on March 28, 2000, the pond had partially filled with 913,000 m3 (740 acre ft) of pH 4.9 water. Another 666,600 m3 (540 acre ft) of pH 3.3 water was pumped in from an adjacent pit (PitA3P- 1). By the end of the project (July 5, 2000), a combined volume of 1,579,000m3(1,280ac-ft or 417milliongal) in PondA3P-2 had been successfully treated to pH 8.2 with 431 t (475 st) of lime. This was two to three times more neutralizer than laboratory trials and detailed chemical titration had predicted. The main reasons for the difference are thought to be the inadequate representation in a laboratory setting of some of the chemical reactions that occurred in the field, including incomplete mixing of reactants, reactions with clay minerals in the pit walls, the kinetics of biologically-mediated reactions and the kinetics of aluminum oxyhydroxide polymerization (aging).

Jan 1, 2002

One of the responsibilities of the Melbourne and Metropolitan Board of Works is to provide a sewerage system for the metropolis of Melbourne which now contains over 2.5 million people. In providing this sewerage system it was necessary for the Board to embark on a large tunnelling programme some 20 years ago. As a result of this extensive tunnel construction programme, tunnel boring machines and shaft sinking methods have been developed to cope with the soft ground and soft to medium rock found in the southern and eastern areas of Melbourne where the majority of the recent tunnelling has been carried out. While in the last few years radical changes in construction methods have not been made, development has continued and improvements have been made, which have enabled the Board to extend the limits of the ground conditions in which it can efficiently construct shafts and also tunnels with boring Machines.

Jan 1, 1976

By David H. Yee

Because of environmental concerns, the Bureau of Mines investigated an anhydrous chlorination process for the recovery of copper from chalcopyrite, Pelletized concentrate was reacted continuously with chlorine in a vertical shaft reactor at 550° to 750° C to extract copper-iron chlorides and elemental sulfur. The resulting molten metal chlorides drained from the reactor and collected in a receiver while sulfur distilled from the top and condensed in a separate unit. The tests were conducted in a 10-cm-diam reactor constructed of glass and in l5-cm-diam reactors constructed from various refractory materials. A high-alumina ramming mix exhibited the best resistance to molten metal chlorides and elemental sulfur in chlorine atmospheres. A reactor made with this high-alumina refractory was operated for 55 hr under actual chlorinating conditions without suffering any deterioration. Tests results show that more than 96 pct of the chalcopyrite was converted to copper-iron chlorides and elemental sulfur. Good separation of the metal chloride and sulfur products was achieved. After filtration, elemental sulfur of greater than 99 pct purity was obtained.

Jan 1, 1977

By Paul R. Thimas, Edward H. Boyle

"The Bureau of Mines evaluated the long-term cost and availability of primary gold production from 135 mines and deposits worldwide. Collectively, the evaluated countries represent 93 pct of world gold production. Total recoverable gold available (as of January 1984) from a subset of 111 significant producing mines and developing deposits in 13 market economy countries (MEC's) is estimated at 810 million tr oz. The Republic of South Africa is estimated to account for 87 pct of total recoverable gold. The United States and Canada account for 4 and 4.5 pct of the total, respectively. Eighty-three percent of total recoverable gold is available at a constant 1984 break-even price of $400/tr oz, and 70 pct is available at $300/tr oz. South Africa accounts for 90 pct of the gold available at $400/tr oz or less.Major conclusions are that (1) South Africa should remain the largest world producer through the year 2000, (2) annual MEC output in 2000 should not be significantly different than current output given constant 1984 gold prices of more than $300/tr oz, and (3) there may be a significant decline in production after 2010 in the absence of major new discoveries and continued development of new mines to offset the depletion of the South African mines. INTRODUCTIONSince the late 1970's the world gold mining industry has been characterized by dynamic growth in production and volatility in price. World production in 1983 was almost 15 pct greater than in 1980, and the short-term trend continues upward. Annual dollar-based price changes since the early 1970's have been unprecedented in both magnitude and volatility. This commodity, which sold for $35/tr oz3 for over a third of a century, reached an annual average $612/tr oz in 1980. Until 1980, the future price of gold seemed set on an upward trend. Since that year, however, world gold prices have fallen by over 50 pct to slightly over $300/tr oz at the end of 1984.Against this background, this study was undertaken to determine (1) the level of world demonstrated gold resources, (2) total and annual availability of gold mine production, (3) long-run production costs per operation and by national aggregates, (4) the economic and technical factors that impact upon cost and availability, and (5) probable future mine production and cost trends."

Jan 1, 1985

By Stewart R. Wallace

Members of the Society, it is a very great honor for me to be here today and to have the opportunity of telling you about some things that have been accumulating in the back of my mind for some time. Before attempting to do so, I should acknowledge my debt to the many people who are responsible for my presence here this afternoon. To do this properly, however, would consume much of my allotted time and I will therefore mention only two men, both of whom were directly involved in the discovery of the Henderson ore body. The first of these was Robert Henderson, now dead, who at the time the work was going on was vice president of Western Operations of the Climax Molybdenum Co. Truly, he provided the environment that permitted the exploration program to function effectively, and the deposit appropriately bears his name. The second man I meant to mention was resident geologist at Urad at the time of the Henderson discovery. I think I should explain right here that the Urad ore body and the Henderson ore body, although entirely separate, are closely related deposits, and that both are located at Red Mountain in Clear Creek County, Colo.

Jan 6, 1975

By Dods G. H, Hewitt W. V

Ashton Mining Limited is currently one of the active companies undertaking gold exploration in Indonesia. Presently 7 Contract of Work areas are being explored for hard rock and alluvial gold. Hard rock exploration is focussed on the Tertiary volcanic arc terrains in which a variety of epithermal mineralisation styles have been identified. At the regional stage remote sensing techniques using Landsat, Spot and SLAR imagery where available, and photogeological studies are carried out in parallel with regional reconnaissance fieldwork programmes. These involve geological mapping and geochemical drainage sampling. Remote sensing techniques have proven useful in both the extrapolation of known geology and the identification of tectonically favourable settings as controls to mineralisation and volcanicity. The variety of mineralisation styles and settings is reflected in the highly variable geochemical signatures encountered. This has necessitated the refinement of sampling methods and sample preparation techniques for pan concentrate, stream sediment and soil samples in specific project areas. At the detailed prospect stage, mapping with particular attention to structural controls, wallrock alteration assemblages identified by petrog- raphy and XRD clay mineralogy, have proved useful in focussing drill targets. Drilling to date has utilised conventional diamond core drilling methods, the use of lightweight, man-portable "Winkie"-type rigs and hammer auger bedrock sampling systems. Geophysics methods successfully employed on various projects have included airborne magnetics and radiometrics, detailed ground magnetic surveys, VLF-EM and SIROTEM.

Jan 1, 1991

By A. J. Leighton

An improved mathematical model with the attendant computer program to calculate multiphase fluid flow in petroleum reservoirs is presented. The model is used to simulate the behavior when a fluid is used to displace hydro-carbon fluids in a reservoir. The method is an expansion of a previously published method, in Bureau of Mines RI 7011, but handles constant injection rate as an alternative to constant pressure. Program documentation is provided along with thorough explanations of the added program features. Using the program, the petroleum engineer can calculate oil recoveries for different flood patterns and operating conditions and select the conditions most likely to optimize recovery. Experience with the previous model demonstrated the need for the improvements in order to simulate reservoir behavior more accurately. The improved method will result in improved oil recovery. In this paper, the significant improvements are described in detail so that anyone interested can put the program to use.

Jan 1, 1975

By M. P. Tixier

Abstract In a review of the application of electrical logging in Canada, examples are .given of long and short distance correlations by means of the electrical logs. The use of MicroLogging for the determination of permeable and porous formations is explained. The question of log analysis for the quantitative determination of fluid saturation and porosity is .discussed. An example is provided to illustrate the significance of the resistivity gradient. The advantages of the new method of the Laterolog are shown, chiefly for the case of wells filled with high-salinity mud. Introduction Electrical logging techniques developed rapidly in Canada at the time an intensive drilling activity started for the exploitation of the Devonian series in Alberta, namely, at the beginning of 1947. The conventional service was soon thereafter supplemented with the latest technica1 improvements. Canada has been among the first regions to take advantage of MicroLogging*, which has proved a most powerful .tool for the investigation of permeable and porous formations; also, the more recent development known as the Laterolog has ?been introduced in Canada. The Laterolog provides a better determination of .the formations, particularly in the case of salty mud where the conventional logging is greatly handicapped. The various methods of electrical logging are now commonly known in oil industry and have been described in numerous publications ( 1) ( 2) (3).

Jan 1, 1951

This paper firstly reviews the requirements for container and hopper design for reliable discharge. Discussion is then directed to the evaluation of the consolidation stresses acting in both in both the cylinder and hopper sections during both initial and flow conditions. Here the vast difference, especially in vicinity of the bin outlet, between the initial or filling and flow conditions is highlighted. This vast difference has major design and operation implications. A further major implication is that all bulk solids must dilate to flow. The opportunity to simultaneously attain reliable discharge and partial moisture removal is also examined.The selection of design parameters to maximise the consolidation stresses in both the cylindrical and hopper sections is detailed. In regard to the latter, it is recommended fine coal bins be discharged using low friction lined transition hoppers with large outlet spans. Such outlets will discharge fine coal in a relatively compacted state. This compaction state should exhibit minimum water retention and short term moisture uptake.

Jan 1, 1998

By Edward Kline

A review and synthesis of literature pertaining to biological consequences of submarine mine-tailings disposal (STD) was conducted. STD can result in massive sea floor sediment deposition. STD may also increase suspended sediment, trace metals, and residual milling reagents in receiving waters. These perturbations, which are highly site dependent, invariably smother benthic organisms, and could potentially affect or alter fish, plankton, and benthos through acute and chronic toxicity, bioaccumulation, behavioral changes, smothering, derived secondary effects, and habitat alteration. Much of the available information concerning STD is unpublished and limited to a restricted number of sites. From this information and related research, it appears that benthic smothering is the only major consequence of a properly designed STD system. There have been cases of metal bioaccumulation due to inadequate preliminary evaluation, Also, shallow water habitat alteration has resulted from STD. Reductions in biological production are likely due to benthic smothering. The rate of ecological recovery after termination of an STD operation varies and is difficult to assess, The consequences of STD are site specific. Additional research is needed concerning possible consequences of milling reagents and the broad implications of benthic smothering. Also, methodologies are needed to allow better prediction of benthic recolonization and ecological implications of metal bioaccumulation.

Jan 1, 1994

Jan 1, 1971

By Christie GB, Mainwaring DE, Leong YK

High solids brown coal slurries have been prepared with concentrations approaching those achieved with bituminous black coals. The high inherent water content and macroporosity of Victorian brown coals have been reduced in a controlled manner by chemical and mechanical means. The hydrophobicity of the coal surface has been increased sufficiently to reduce the tendency for swelling and water uptake. This together with densification has allowed the solids content to be progressively improved from 25% solids with raw coal to 65% solids with modified coals. Both raw brown coal and modified brown coal suspensions show shear thinning behaviour resulting in lower viscosities at higher flow rates. All coal suspensions displayed a yield stress once sufficient solids concentration was achieved. This yield stress can be used in the prevention of solids settling. Under simple shear mixing the network structure that provides the yield stress quickly breaks down to a low viscosity fluid with reduced yield stress and a pumpable consistency. The time necessary for structural recovery is in the order of days permitting shut-down and start-up of fuel delivery systems.

Jan 1, 1987

By Egons R. Podnieks, Wallace W. Roepke

Mining technology to utilize vital lunar resources will be required for any commitment to permanent lunar basing. Lunar mining must be viewed both as a major supporting element for space resource commercialization and for creation of human settlements on lunar and planetary surfaces to support long-range space exploration. The Apollo missions to the lunar surface and results from fundamental research on analogue lunar rocks by the Bureau of Mines, and others, have provided the initial data for developing lunar mining technology. The multi-disciplinary research projected in this paper outlines the scientific and engineering needs to realize the lunar mining goals.

Jan 1, 1990

By Alexander RB, Hollis AJ

The magnitude of the payloads carried by mine haul trucks can have a strong influence on the mine production rates and costs. Consequently control of truck payloads is highly desirable, but in many mines the unavailability of means for measuring payloads reliably, accurately and easily has resulted in a low level of control over truck payloads. Consideration is given to two techniques which are applicable to the measurement of payloads carried by mine haul trucks, namely truck weighing and direct measurement of payloads with truck based systems. Accuracy assessments for two types of truck weighing platforms and two prototype truck based direct payload measurement systems are provided. Results show that weighing platforms based on hydraulic components have proved inadequate, while strain gauge type weighing platforms can estimate payloads to within 2% of true payload when installed, maintained and used correctly. The assessment of the two prototype truck based direct payload measurement systems shows that a high proportion of payloads were estimated to within 5% of the payloads derived from accurate weighing platforms and that these systems appear to have the potential to provide convenient and accurate measurement of payloads. This should enable payloads to be much better controlled than has been possible to date. Predictions of the effect of payloads on production rates and some components of truck haulage costs are possible and some typical results are presented. Accurate prediction of the effect of payloads are not yet possible for some major components of truck haulage costs.

Jan 1, 1986

By John H. Bassarear, A. A. Dor

INTRODUCTION Primary grinding mills as defined in this paper, are autogenous or semi-autogenous rotating, tumbling mills having a coarse feed with a top size usually varying from 150 to 300 mm (6 to 12 inches). Most frequently, the feed to these mills is the product of primary crushing plants but in some cases run of mine ore is used as feed such as at Benguet, McDermitt, L-Bar Sohio, Bear Creek and others. The size of the largest lumps in the mill feed is principally determined by limits set by the mill feed trunnion diameter and by the type and size of conveying equipment used for handling and of bins and stockpiles used for storage. The use of primary mills in mineral processing plants has expanded very significantly in the last twenty years, and they have been successfully applied to the treatment of a wide variety of ores in both wet and dry grinding applications. In the present state of technological development for primary grinding mills, there is a wide choice of acceptable options with respect to type and size, grinding flowsheet and grinding media. The choice of the optimum combination which would result in the most satisfactory condition of operation, from the standpoint of both metallurgical results and costs, depends on the nature of the ore, the required characteristics of the grinding products and on various geographic and economic circumstances. The effects of such factors and considerations on the choice and sizing of primary grinding mills and flowsheets are reviewed and discussed in the following pages. PRIMARY MILLS SELECTION Inherent Characteristics of Primary Grinding Primary grinding is complex because it involves several comminution mechanisms which occur simultaneously and to some degree interfere with one another. These mechanisms of impact, attrition and abrasion have been described earlier. The relative importance of these three main grinding actions and their mutual balance resulting in a continuous uniform operation of the mill depend to a very large extent on the nature of the ore and its physical properties. Homogenous, single mineral ores will behave quite differently from heterogenous ores consisting of different minerals bound together along defined

Jan 1, 1982

This study is to compare reinforcement of rebar and spiral bolts using laboratory pull-out test. For this purpose, the pull-out test was performed in laboratory for a curing period of 7- and 28-days. Based on the results of the laboratory pull-out test, the pull-out load of two support members rapidly increased with displacement until the breakpoint and then gently increased with displacement. The maximum pull-out load of spiral bolt was larger than that of rebar bolt. This implies that a spiral bolt is more stable than a rebar bolt for securing the stability of a ground or rock mass when a support was installed in a ground or rock mass under the same condition. In addition, the maximum external pressure of two support members increased with pull-out load and with displacement and the distribution of external pressure was commonly larger at the upper part than at the lower part of specimen. This indicates that the bond failure location by pull-out load should be mainly occurred at the surface portion of specimen. In conclusion, the reinforcing effect of a support depends on a curing period and a type of support member, and reinforcement of a spiral bolt is more effective than that of a rebar bolt.

Dec 6, 2010

By Kenneth R. Hancock

Iron oxides are unique in that they are the only significant colored mineral found in a natural state suitable for use as a pigment after being pulverized to pigmentary size. The current world production of iron oxide pigments is estimated by the author to be between 499 and 590 kt (550,000 and 650,000 st) based on 1979 data. The fact that highly colored natural deposits of iron ore are found throughout the world accounts for its use in prehistoric man's artistic cave paintings. These early artists did not realize that they had established man's first paint test fence which now has some 20,000 years of exposure. In addition to abundance, constituting about 7 % of the earth's crust, iron oxides have the advantages of low cost, permanency, and are not toxic. Through the centuries, succeeding civilizations have utilized iron oxides as a major source for decoration and protection when coloring was desired. In the last century the chemical industry has improved on nature by developing a complete range of synthetic iron oxide pigments which surpass the pigments produced from natural iron ores in uniformity, color quality, and chemical purity. In the United States alone, the combined production of natural and synthetic iron oxides produced sales of over $28,000,000 in 1970 (Stipp, 1970) and increasing to $97 million by 1980 (Spinrad, 1980). Nomenclature With the increasing importance of the synthetic iron oxides it is necessary to make a distinction between the natural or mineral pigments and the synthetic pigments. Natural pigments are those products which are derived from selected ores and should not be confused with iron ores mined for steel production. Iron ores that are mined for steel must be capable of being mined and reduced to iron on a commercial basis. These ores are selected on the basis of iron content and processing economics. It is therefore unusual when iron ores for steel production are suitable for use as mineral pigments. Natural pigment ore sources are selected for their special physical-chemical properties and can command a premium price. Synthetic pigments, and in this instance iron oxides, are those pigments produced from basic chemicals. Through chemical synthesis pigmentary sized particles are produced as opposed to comminution, the major procedure common to all natural iron oxide pigments. Classification An important characteristic of a pigment is its color and, therefore, a logical separation can be made on this basis. A. Yellow Iron Oxide Pigments 1. Natural mineral origin a) Goethite b) Lepidocrocite c) Ochres d) Siennas e) Limonite 2. Synthetic pigments a) Goethite B. Red Iron Oxide Pigments 1. Natural mineral origin a) Hematite b) Siderite (calcined) c) Pyrites (calcined) 2. Synthetic pigments a) Hematite C. Brown Iron Oxide Pigments 1. Natural mineral origin a) Umbers b) Limonite (calcined) c) Siderite (calcined) d) Goethite (bog ore or sulfur mud) 2. Synthetic pigments a) Blends of hematite, goethite, and magnetite

Jan 1, 1983