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By John Birkinbine

EXTENDED discussions, by inviting attention to problems affecting the conservation of natural resources, have encouraged investigations as to their sufficiency, with the general result that the more thorough the examination, the less cause appears for anxiety as to the exhaustion or serious depletion of these resources. The extent of industrial development, the large plants and the enormous volumes of materials required, when compared with conditions a few decades ago, are sufficiently startling to enlist the attention of those who "fear .the pace," and yet in but few instances has real solicitude for the future. been warranted by a knowledge of true conditions. In a former communication, presented 5 years ago,1 I endeavored to emphasize the fact that true conservation represented the best utilization of reserves and not the locking up of resources for future use; a conviction which has become more pronounced as the subject was investigated. Prophecies of the, early exhaustion of mineral resources have raised the question as to our permanent reliance upon these, and encouraged inquiries which have in most cases developed reassuring conditions. But the fact that the future appears less dark than prognosticated cannot excuse wastefulness or improvidence; and detailed study which demonstrates an apparent abundance of natural resources should encourage their best application. In making inventories of resources one is liable to confine conclusions as to availability upon present circumstances and conditions in the past, or to formulate data for the future upon methods which are rapidly being displaced. In reserves which are not reproductive, such as minerals, the possibilities of exhausting the supply are startling if estimates assume that future extensions will follow methods which were less economical than those now employed, or to he used, and we dare not claim that the limit of advanced practice has been attained.

Jan 9, 1914

By Martin E. Nelson

Several heavy metal separation techniques are currently being developed for soil remediation at various Department of Defense and Department of Energy (DOE) Facilities. The majority of these techniques involve a wet process using water, PH modifiers or other compounds. The United States Naval Academy (USNA) has developed a dry process for heavy metal separation. The process uses air classification technology to concentrate the metal contaminant into a fraction of the soil. The advantages of this dry process are that it creates no contaminated by product and uses commercially available technology. The USNA process is based on using a Gayco-Reliance air classifier. Tests have been conducted with the system at the Naval Academy and the University of Nevada-Reno (UNR). The USNA tests used soil from the Nevada Test Site mixed with bismuth at a concentration of 500-1000 ppm. The UNR tests used soil from four DOE sites mixed with uranium oxides and plutonium at an activity level of 100-700 pCi per gram. Concentration of activities and volume reduction percentages are presented for the various soils and contaminants tested.

Jan 1, 1995

By Pedro Henrique Teshima Shioga

Quando processos de engenharia de superfícies multifuncionais que combinam fases de propósito orientadas são aplicados a substratos moles, uma combinação de alta resistência ao desgaste, suporte de alta carga e baixos coeficientes de atrito podem ser obtidos. Neste estudo, os efeitos de diferentes camadas nitretadas no comportamento tribológico de revestimento Diamond-Like-Carbon (DLC) depositado sobre aço SAE 1040 são investigados. A nitretação foi conduzida sob diferentes temperaturas e misturas de gases para criar três camadas de nitretos distintas: duas camadas de compostos com predominância de fases e e ?’ e uma camada de difusão. Todas as superfícies foram então revestidas com DLC, depositado via Plasma-Enhanced-Chemical-Vapour-Deposition (PACVD). As fases de nitreto foram analisadas utilizando difração de raios-X e a topografia da superfície foi analisada por interferometria de luz branca e microscopia eletrônica de varredura. O comportamento tribológico foi investigado utilizando esfera e plano com movimento alternado com carregamento incremental até a falha do filme DLC. Os testes tribológicos indicaram que o melhor desempenho foi alcançado por uma específica combinação de dureza, rugosidade superficial e tipo de nitreto. A melhor capacidade de mancalização entre o revestimento DLC e o substrato mole foi alcançada quando a camada de nitretos constitui-se apenas de uma camada de difusão.

Aug 16, 2017

By Fumitaka Tsukihashi

Increasing amounts of steel scrap are being used as resources for steelmaking. Therefore, there has been a growing interest in the removal of harmful tramp elements such as antimony, zinc, tin, arsenic, bismuth, lead and copper from the molten steel. The problem that should be solved is the economic removal treatment of residual tramp elements in the steelmaking processes and the production of high quality steel by reducing the effect of the contaminated tramp elements and satisfying the environmental regulations. In this paper, the available thermodynamic data of the residual tramp elements in the molten steel arc summarized and the possibility of the removal of residual tramp elements from the molten steel is thermodynamically estimated.

Jan 1, 2003

By W. D. Macleod

This paper describes a mineral dressing process for the upgrading of tin ores. The process described is called 'agglomeration' and. is similar in many respects to flotation. Many variables have been examined experimentally both on batch and continuous operations and are reported upon herein... Using a Mt. Pleasant tin ore, assaying 0.5% Sn, an upgrading to 8% Sn, with a recovery of 95% could be obtained by this process.

Jan 1, 1966

By Henry C. Meeves

The Bureau of Mines, between 1956 and 1963, examined 18 major pegmatite districts in Arizona, Colorado, New Mexico, South Dakota, Utah, and Wyoming to evaluate their content of beryllium, a material in short domestic supply that has become increasingly important to modern industry. This examination report includes the salient statistics on the production of pegmatite minerals other than quartz and feldspar; and brief descriptions of 170 specific pegmatite deposits.

Jan 1, 1966

By S. G., Lasky

IT seems to be in the nature of concepts that they have many meanings, and that the meaning best reflecting the primary interests of a person tends to be accepted by him as the normal meaning of the concept. The concept of ore reserves is no exception, for there is no unanimity of meaning among the several groups of us who are interested in ore reserves, nor even among the individuals of a single group. The groups most interested in ore reserves would seem to include at least the mining industry, perhaps State taxing agencies, and the Federal Government in all its diversified activities, and I would include also the citizenry at large or at least that part of it that consciously thinks about problems-of national welfare. To each of these, and to different individuals within them, the term reserves represents something different, and the farther away the individual or group gets from physical contact with the ore, the more abstract does his or its concept become. It is something different to the policy maker from what it is to the fact-finder or to the miner.

Jan 1, 1945

By Dan A. Brown

Outline ? Basic Concept of ACIP Piles ? Factors Affecting ACIP Pile Performance ? Applications: - Favorable Conditions - Unfavorable Conditions ? Design for Axial Loading ? Lateral Loading Considerations ? Summary & Conclusions

Jan 1, 2004

By N. J. Alderman, D. J. Clowes, N. I. Heywood

The effects were studied of the presence of comminuted flint on the rheological characteristics of chalk slurry pumped through a 92-km long pipeline from Kensworth Quarry to Rugby Cement Works in the UK, and their impact on the pipe flow conditions. Flow curves were measured for 63different chalk slurry samples; these were described by the Bingham plastic model. In addition to observing trends in the yield stress parameter and plastic viscosity in the model with variations in both flint concentration and dispersant additive, use was also made of slurry viscosity values at a reference shear rate of 60 s-1for the pipe flow. It was found that chalk slurry viscosity decreases with increasing flint content up to 10% by weight for a given additive concentration, and increases with increasing additive concentration from 0.7 to 1.0%, for a given flint content. The pipeline flow regimes were identified using the critical value of the Bingham Reynolds number for laminar flow breakdown. For Bench 11 (quarry bottom) chalk slurries, it was observed that all sections of the pipeline operate in the turbulent flow regime for the nine different formulations and for the three pipe diameters used along the pipeline. However, this was not always the case for Bench 1(quarry top) slurries. It was therefore recommended that chalk slurries prepared from Bench 1 should not be used because of the strong likelihood that laminar flow conditions will occur owing to the presence of higher clay concentrations within this bench. This, in turn, will lead to an unsafe operation of the pipeline because of the potential for coarse particle settling. Likewise, blending of chalk from Bench 1 with the lower benches such as Bench 11 could be problematic and this requires further experimentation.

Jan 1, 2007

By A. V. Tarasov

The nonferrous metals industry has been a sector with one of the highest growth rates during the recent years. The prospects for the Russian metals industry during the period until 2010 are associated first of all with a growing domestic demand for its products. The technological level of the metallurgical operations in Russia is relatively low in comparison with industrially developed countries: the average energy requirement is higher by 20% to 30%; the amount of generated waste in the process of rolled products manufacture is twice as high; the average labor productivity is lower by 2.5 to 3.0 times; the overall negative environmental impact is twice as high. Improvement of the technological level of the nonferrous metals production under the conditions of market economy is possible by application of innovative technologies for the development of this sector. The main trends for development of the nonferrous metals sector are: - meeting of more stringent requirements to the quality of concentrates; - more complete recovery of associated elements as commercial-grade products; - development of continuous process lines based on autogenous, resource-saving and environmentally safe processes; - use of combined technologies, including pyrometallurgical, hydrometallurgical and upgrading processes; - expansion of the fields of application for nonferrous metals and their alloys.

Jan 1, 2006

By Daryl E. Radcliffe

Ninety-seven roof bolts were instrumented with strain gages and resin-grouted in three areas of the Bear coal mine, Somerset, Colo., by the Bureau of Mines. Measurements taken with these instruments indicate roof support is achieved through a combination of point suspension and resistance to vertical and horizontal stresses caused by localized shearing in the roof. The localized shearing results in bending of the bolts, yielding due to high vertical stresses, and the transfer of high loads to the bolt head or plate.

Jan 1, 1980

This short paper outlines the authorÆs views regarding the progress we have made as an industry in managing mining assets over the past 500 years. It represents a personal view û but one founded in fact-based observations of mining companies and of the mining industry in general. There is no doubt that AgricolaÆs views as expressed in De Re Metallica (1556) were visionary. There is also little doubt regarding another issue û that whilst a great deal has been learnt about the management of mines since AgricolaÆs time, observations suggest that best practice management is the exception rather than the rule across our industry. Although insights regarding the successful management of mines have become apparent, we still witness unnecessary errors in our industry that lead to the loss of shareholdersÆ funds. By highlighting some aspects of current best practice, particularly in the arena of operations management, it is hoped that this short paper contributes a small step along the next 500-year-long learning curve. The paper concludes with a brief description of the progress and impact of continuous improvement initiatives at Kalgoorlie Consolidated Gold Mines (KCGM). Located in the Kalgoorlie Goldfields, KCGM is currently AustraliaÆs largest gold mine producing over 800 000 ounces of gold per annum. Improvement initiatives at KCGM look set to deliver some $100 million in value over life-of-mine.

Jan 1, 2004

By B. Q. Xiao

The nitrate content is an important factor for environmental water samples and flour. In a 0.35 mol/L H2SO4-2NO solution, has a strong catalyzing function on the decolourization of Gallocya-nine (GC) oxidated by NaBrO3. Based on this, a novel method was developed to measure the NO and -3NO concentrations in water and flour. The flow injection technology was introduced into the analysis system. A single-valve dual- cingulums to inject which the Copperized-Cadmium slice and the reduction zone are isolated. The optimum solution for this method contains 1.48×10-4 mol/L GC, 0.06 mol /L NaBrO3 and 0.2 mol /L of NH4-2NOCl. Two empirical equations were proposed to calculate the and -3NO concentrations based on the measured signals. It can be used to measure -2NO of from 0.001 mg / L to 2.0 mg/L and -3NO of from 0.002 mg / L to 2.5 mg/L. The measurement frequency can be up to 20 samples / h. The relative standard deviation for eleven samples is less than 5%.

Jan 1, 2014

By A. Bauer, P. Calder, N. H. Carr, G. R. Harris

Since both rotary and jet piercing drills are used by the Iron Ore Co. at Smallwood, it is often desirable in planning to know in which regions of the orebody or new orebodies a particular drill will be the most economic. This makes it necessary to establish a correlation between drillability and pierceability and some physical rock properties. For rotary drills a good correlation was found with penetration rate and grinding factor index. The jet piercers were found to have a reciprocal relationship in the sense that the best rotary ground was the worst jet ground and vice versa. It is also indicated how an economic comparison could be made using these penetration rate versus grinding factor index curves, the hole size distribution curves for single pass and chambered holes and the mine distribution curve for grinding factor index. A discussion is presented on the fuel oxygen ratios to be used in jet piercing and on the site gas sampling and analysis which has been used to set up the drills. The fuel has been cut back so that stoichio-metric conditions exist, carbon monoxide is drastically reduced and pop-up or exploding holes eliminated. No decrease in penetration rate has been observed contrary to the published results of previous workers. The blasting procedure and results at Smallwood are discussed and the operation of Iron Ore Co.'s slurry pump-mix truck is also described briefly. Smallwood mine is part of the Iron Ore Co.'s Carol Lake operation and is situated in Labrador, 240 miles north of Sept-Iles, Quebec. Last year 15 million tons of crude ore were crushed to yield 6.3 million tons of concentrate and pellets. This year the figures will be 17 million tons of crude and 7% million tons of concentrate and pellets which is the full plant capacity. Carol Lake ores consist primarily of specularite and magnetite mixed with quartz. For convenience the ore has been split-into the following classifications depending on the percentage of magnetics in the sample, shown in brackets: specularite (0 to 10%), specularite-magnetite (10 to 20%), magnetite- specularite (20 to 30%), magnetite (>30%). The order of classification also represents the order of increasing grinding difficulty - the specularite generally being the easiest and the magnetite the hardest. The orebody also contains a small percentage of waste materials consisting of limonite carbonate, quartz carbonate and quartz magnetite. The first two materials are among the softest in the mine, generally softer than the specularite, and the quartz magnetite is amongst the hardest. The bulk of the material in the mine is of the specularite-magnetite and magnetite-specularite classifications. As a result of test drilling at Smallwood in 1960 with rotary, jet and percussion drills, the Iron Ore Co. purchased four JPM-4 jet piercers for the bulk of production drilling and set up an oxygen plant to supply 20 tons of oxygen per day. This oxygen is sufficient for two machines operating full time and one part time. In addition, there are two 50-R, one 60-R and one 40-R machines in use. The benches are 45 ft high and 50 ft holes are generally drilled. JET DRILLING At the onset of jet drilling in the late fall of 1962, two major problems were encountered: 1) freezing due to winter operations; experience and the use of heat at more places, such as the rotary head, has eliminated this,'" and 2) exploding or "popping" drilled holes; this happened frequently (several holes "popping" each day) and was the cause of two lost time accidents. In one instance a hole was being measured with a tape which fell down the hole causing it to "pop." Safety glasses though pulverized saved the wearer's eyesight. Various methods were then employed to detonate the holes before measuring or loading (dropping lighted rags of fusees down, or sparking across a spark gap). These methods were time consuming and far from completely successful. Consideration was given to the fuel oxygen ratio on the machines and what this would produce in the way of product gases. A fuel oxygen weight ratio of 0.35 which was quite oxygen negative was being used. Theoretically appreciable carbon monoxide would be produced at this fuel oxygen ratio. On the close down procedure of the jet which calls for low oxygen after flame out, oxygen would be left in the hole along with this carbon monoxide. This is an explosive mixture. The fuel oxygen ratio was cut back to stoichiometric

Jan 1, 1967

By Benjamin W. Haynes

Analytical procedures are described for the quantitative determination of 16 elements (As, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, TI, and Zn) and 7 ionic species (NH4, C032-, CI-, F-, NO3-, P043-, SO42-), identification of major and minor mineral components, and measurement of physical properties associated with manganese nodules and nodule processing reject waste materials. Compound identification methods discussed include X-ray diffraction, infrared spectroscopy, scanning and transmission electron microscopy, selective area electron diffraction, and optical and reflected light microscopy. Methods for elemental analysis include atomic absorption spectrophotometry, inductively coupled plasma emission spectroscopy, neutron activation analysis, fluorescent X-ray spectrography, and ion chromatography. Thermal gravimetric analysis, ultraviolet-visible spectrophotometry, ion specific electrodes, and standard wet chemical procedures are briefly discussed. Physical properties determined in manganese nodule materials include grain size distribution, specific gravity, triaxial shear, permeability, maximum density, Atterberg limits, and slurry density. The results of a round-robin analysis of an ammonia process waste material and manganese nodule standards demonstrate the applicability of the discussed methods. Tests discussed for the evaluation of the waste materials for disposal options include the Environmental Protection Agency (EPA) EP toxicity test, the ASTM shake extraction test, and the U.S. Army Corps of Engineers EPA seawater elutriant test.

Jan 1, 1983

By James J. Brady, Joginder S. Bhore, Robert B. Gordon, Jimmy W. Honeycutt

The authors of this paper have a combined construction experience of 70 years. They have served as engineers and managers on projects throughout the United States and Canada. Approximately 50 shafts have been sunk under their direct and daily participation. Several shafts have been selected from each of their experiences and have been briefly summarized here. SHALLOW SHAFT SINKING Sinking shallow shafts in highly urbanized areas adds an additional set of problems to those encountered in normal sinking operations. During the time between July, 1975 and early 1981, a series of shafts were sunk for The Washington Metropolitan Transit Authority. All of these were located along the "A" line, starting soon after the route departed from its path along Connecticut Avenue, proceeding to Wisconsin Avenue and then along Wisconsin Avenue to the city line at Western Avenue. (See WMATA System Map, Figure 1) The first three shafts were subcontracted from Morrison-Knudsen & Associates, Contract A9a, in July, 1975. They were: Albemarle Street - 27'6" diameter, 78'O" deep Brandywine Street - 30'6" diameter, 88.6' deep Ellicott Street - 33'0" diameter, 110'0" deep

Jan 1, 1985

By R. L. Rickett, N. C. Fick

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By N. C. Fick, R. L. Rickett

Despite the large volume of literature on alloys of iron and silicon,' there is little published information dealing specifically with the constitution, at various temperatures, of the alloys containing less than 0.10 per cent carl~on and from 0.5 to 4.5 per cent silicon that are used extensively in the electrical industry. Because such information was needed by those engaged in the production of these alloys in sheet and strip form, the constitution nas determined of a series of commercial silicon steels containing 0.05 to 0.08 per cent carbon and 0.20 to 4.1 per cent silicon, over the temperature range 1300° to 1500°F. These alloys were all from regular production heats and of commercial quality. The results of the tests are given in Fig. I and for comparison the constitution diagram of iron-silicon alloys with 0.01 to 0.02 per cent carbon, taken from the literature, is also presented Material and Procedure All steels were hot-rolled to a thickness of 0.060 to 0.080 in. and used in this condition. Their chemical compositions, including over-all check analysis, and "center" analysis for carbon and silicon, are given in Table I. The so-called center analysis was determined on samples pickled to remove the outer surface and leave only the center third of the gauge thickness—the portion of the sample on which metallographic ratings were based. In most, but not all, of the alloys, slightly higher carbon was found at the center than when the whole strip was sampled; the two methods of sampling show relatively little difference in silicon. Two of the steels, A and E, contain relatively high phosphorus, while I and K are somewhat higher in manganese than the others. The procedure consisted essentially of heating specimens (about 1/16 by 3/8 by 3/4 in.), protected from oxidation or change in carbon content, at a temperature in the desired range and for a selected period, after which they were quenched in iced brine; the degree of transformation that had then occurred was determined by metallographic examination. The soaking periods were selected after preliminary investigation had shown that a con-

Jan 1, 1947

By John J. Sammarco

Computer-related accidents have caused injuries and fatalities in mining as well as other industries. Normal accident theory (NAT) explains that some accidents are inevitable because of system complexity. NAT is a classic argument in organizational sociology although it has been criticized as having imprecise definitions and lacking criteria for quantifying complexity. These limitations are addressed by a unique approach that recasts this organizational theory into an engineering-based methodology to quantify NAT complexities of computer-based systems. In this approach complexity is categorized as external or internal. External complexity is defined by the external behavior of a system, and is quantified by these dependent variables: system predictability, observability, and usability. Dependent variable data contain the perceptions of 32 subjects running simulations of a system. The system?s internal complexity is characterized by modeling system-level requirements with the software cost reduction (SCR) formal method. Model attributes are quantified using 15 graph-theoretical metrics?the independent variables. Five of 15 metrics are correlated with the dependent variables as evidenced by structure correlations exceeding 0.25, with standard errors <0.10 and a 95% confidence interval. The results also show that the system predictability, observability, and usability decreased as NAT complexities increased. This research takes a step forward in operationalizing NAT for computerized systems. The research benefits mining and other industries as well.

Jan 1, 2005

By Xin Zhang, Xu Zhang, Hao Bai, Ning Li

Organic Rankine Cycle (ORC) is an effective technology for low-grade waste heat power generation. In this paper, the thermal-dynamic performance of ORC system, in which low-temperature waste heat (from 40-140oC) is used as heat source, was evaluated with software RefProp8.0. The result indicates that in the range of low temperature, the working fluids like R601, R601a, R600a, R141b, R245fa and R245ca have better thermal performance. Furthermore, pilot-scale experiment using R245fa as working fluid was conducted, which validated the operation of the system for low-grade waste heat recovery. Finally, the economic feasibility of ORC has been analyzed for an ORC system using the waste heat from quenching water of blast furnace slag (80oC). According to the analysis, the project is reasonable in economy because the recovery period of investment is less than 4.2 years and environment-friendly since the CO2 emissions can be reduced by almost 43650.68t annually.

Jan 1, 2016