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By E. M. Wise

WHEN man became dissatisfied with the mere utilization of physical force and began to use weapons, he made a definite stride forward. At first he used sticks, animal bones and stones, often rudely shaped to some particularly lethal form. These devices, while crude, were moderately effective. How- ever, some of the brighter men of the tribe found that certain particularly heavy "stones" were somewhat ductile and could be hammered into more effective weapons than those previously known. Later, probably through the misuse of one of these weapons to stir the campfire, it was found that heating softened and perhaps actually melted the material. The process of annealing had been discovered! Smelting the more easily reducible metals was in all probability one of those fortuitous accidents which was followed up by thoughtful researchers who ultimately developed the technique of mixing various ores to produce bronze and even some of the nickel content alloys. The resulting products were at first lumps of more or less ductile material which could be hammered to shape, and were thus incidentally hardened by this process. The hardening of metals by alloying and cold working remained for many centuries the only known methods for improving their properties.

Jan 1, 1931

By M. King Hubbert

DURING the past summer the writer was asked by the Illinois State Geological Survey to make a study of some of its economic geological problems with regard to the applicability of geophysical methods of prospecting to their solution. The following four problems were sug-gested for investigation: (1) the fluorspar area of Southern Illinois, (2) oil structures in the south central part of the state, (3) the lead and zinc-bearing area of northwestern Illinois, and (4) the water supply and gravel deposits of the glacial drift. The prime requirements were to find a means of obtaining a maximum of useful information with a fairly modest outlay of expenditure for technical staff and equipment. The method of procedure adopted was that of making a preliminary study of each of the problems named by means of available office data and published reports with supplementary field reconnaissance where necessary.

Jan 1, 1932

By José Ricardo Nunes de Macedor

Com o crescente zelo ambiental, os polímeros biodegradáveis ganharam importante papel no mercado mundial. Em especial, o amido é um destaque por apresentar preço baixo e alta demanda, contudo possui grande fragilidade mecânica e os seus filmes são muitos hidrofílicos. Outro importante polímero biodegradável é o poli(ácido lático) que possui, alta resistência mecânica e transparência, quando comparado com o amido termoplástico, permitindo sua aplicação em embalagens alimentícias. Contudo, o PLA ainda possui custo elevado, quando comparado ao amido e até commodities, como o PET, PP e PE. Estudos com algodão, material em grande produção e baixo custo, retratam ganhos nas propriedades mecânicas sem perda da biodegradabilidade em compósitos. Assim, este trabalho objetivou preparar, por meio de homogeneizador termocinético KMixer e prensa térmica, placas de compósitos de PLA contendo amido (0, 3 e 5% m/m) e fibras de algodão in natura processadas (0, 10 e 20% m/m). As amostras foram caracterizados por espectroscopia na região do infravermelho com transformada de Fourier (FTIR), ângulo de contato estático e ensaios mecânicos (módulo de Young, resistência à tração e alongamento na ruptura). As análises mostraram que a adição de fibra de algodão compensa a perda de resistencia à tração ocasionada pela adição de TPS. Tanto a fibra como o amido aumentaram a molhabilidade do compósito.

Aug 8, 2018

The resource industry must prepare for the inevitable shift towards automation as an operational objective. Although this may seem like a distant concern, many mining companies and equipment manufacturers are already conducting full-scale automation trials. The necessary technology is advancing at a rapid pace yet the training of people to support it at the trade level lags far behind. Those given the responsibility of installing and maintaining automated equipment in the mining environment require a unique set of skills and knowledge. These training needs demand attention to ensure that the wider uptake of automation is sustainable and achieves its full potential.   This paper documents work undertaken by CRCMining and the Mining Industry Skills Centre towards establishing a training framework seeking to address the needs of trade level personnel tasked with the support of automation equipment. A comprehensive definition of the skills and knowledge required by the hypothetical automation-specialised tradesperson is presented. The training pathway identified for these personnel is also described. This work forms part of the Mining Industry Skills Centre's Automation Skills Formation Strategy, funded by the Queensland Department of Education and Training.

Jun 1, 2010

Nine case studies are presented to illustrate how risks can be, minimised or quantified during pit optimisation, utilising Whittle Four-D software. Each case study covers a specific problem that has been encountered from a wide variety of pit optimisations. Case A: Maximising profits when the tenement owner is paid a royalty on tonnes processed. Case B: Allocating product prices, rather than a single commodity price during optimisation. Case C: Quantifying processing costs that are affected by penalty elements in the ore. Case D: Exploration expenditures below current pits can be quantified through the use of simulation techniques. Case E: Alternative strategies can be quantified when pits are restricted by tenement boundaries. Case F: Relocation of mine infrastructure that requires large capital expenditures, can be simulated by allocating costs to an area during optimisation. Case G: Evaluating alternative corporate strategies during pit optimisation. Case H: Sensitivity analysis for price, processing cost and mining cost. Case I: Quantifying the advantages of using additional mining capacity during the early periods of mining.

Jan 1, 1994

By Rudy Rogers

Gas hydrates have unique properties of storing selective gases. As much as 180 volumes of gas (standard conditions) per volume of hydrates may be stored. Recognizing the need for natural gas storage near electrical power plants for peak load use, DOE funded our laboratory to investigate gas hydrates as an economically viable storage means. Our developed process forms hydrates and self-packs the hydrates by only maintaining the gas pressure above a surfactant/water solution while hydrates form and self-pack. The laboratory process was scaled-up and demonstrated storage of 5300 scf of natural gas in hydrates. Subsequent to the demonstration, we discovered preparation procedures whereby laboratory gas hydrates could be stored at 1-atm with less than 1% decomposition over multiple days. The paper will discuss how these two advancements offer potential ways to recover vent gases as well as released hydrate gases from the seafloor. Keywords: gas hydrates, methane storage, surfactants, hydrate stability

Jan 1, 2008

By Richard R. Klimpel

This paper reviews some of the factors involved in selecting amine flotation reagents used to remove silica from ores. A comparison is made between the chemical reagent design approaches used to identify flotation reagents that are used to recover silica- and oxygen-containing minerals and the chemical reagents used to recover sulfide minerals. This introduction gives practitioners who are involved with oxide- and carbonate-type minerals and who may not be familiar with sulfide mineral flotation some ideas of the chemical reagent design challenges that exist with froth flotation on a broader scale and why oxide type mineral flotation reagents are what they are. This is followed by several sections that discuss various classes of available amines. The closing sections emphasize that the optimal choice of an amine collector depends not only on that amine's specific chemical characteristics and costs but also on the operating conditions, especially the flotation feed particle size distribution.

Jan 1, 1999

By K. M. Stone, N. J. G. Masson, A. C. Woollett

The Jabali zinc deposit in Yemen contains at least 9.4 Mt (10.4 million st) of ore at a grade of 10.7% zinc, 2.2% lead and 77 g/t (2.2 opst) silver. The zinc occurs as smithsonite with minor hydrozincite. The Jabali ore does not produce a zinc concentrate of sufficient grade to be acceptable to a conventional zinc smelter, and it has been necessary to formulate a less-conventional development plan. This involves the construction of a mine and concentrator at Jabali and a metal production facility using a new flowsheet designed specifically for the treatment of oxide material at Yanbu, Saudi Arabia. To give the facility the necessary economies of scale, the Jabali concentrate will be supplemented by feed from other deposits, this may be either oxide or sulfide material. The paper outlines the geology and proposed mining and treatment operations at Jabali, presents the flowsheet for Yanbu and estimates preliminary costs for both operations.

Jan 1, 2003

By W. G. Matteson

The Gulf Coastal plain of the southern United States is that area bordering for a large part, the Gulf of Mexico and extending inland and northward to the main interior highland region. It is more or less V-shaped and includes the States of Florida, extreme southern Alabama, all .of Mississippi and Louisiana, the eastern and southern half of Arkansas, and the eastern, southeastern, and southern portions of Texas. While the contents of this paper apply to. the Gulf Coastal plain in general, they are intended to refer more specifically to that portion of the plain included between the 90th and 97th meridians, and the 29th and 33d parallels, an area that may be described geographically as comprising western Mississippi, all of Louisiana, part of eastern and all of south-eastern Texas. It is within this area that numerous and prolific oil pools have been developed during the last 17 years.

Jan 2, 1918

By B. Salopek, D. Rajkovic, D. Rumenjak

Among other types of sustainability indicators, linguistic variables have been proposed. During the past few years considerable effort for using the fuzzy logic and linguistic variables (LVs) in environmental decision-making for the mineral industry has been made. The linguistic variables defined could, among others properties, describe the property of acceptability for environment for various environmental indicators. Some proposals for construction of such variables are based on administrative decisions from environmental impact assessment procedures for mining, which provide information for acceptability of quality kind for environment (e.g. obtained from public participation, experts, environmental administration). The measures of evidence for construction have to be based on sets (not only on the members of sets). The administrative decisions with their statements and explanations could be considered as such sets. The measures of evidence appropriate are plausibility and belief measures. Using the more elaborated methods from the theory of evidence, the better estimation of those measures could be achieved. The methods of constructing the linguistic variables, previously suggested and based on obtained measures, are also discussed.

Jan 1, 2011

By M. J. McPherson, P. Mousset-Jones, G. Danko, I. M. Konduri, F. Calizaya

The flow of air through a bare rock, underground airway is affected by the size and frequency of the micro- and macro-asperities of the rough surface. The focus of this study is to characterize this roughness using the coefficient of friction, the friction factor and the fractal dimension. The rough surfaces were identified by two sets of 177 and 78 transverse profiles measured by a laser profiler along the length of an underground airway at the Sunshine Mine, Idaho. Based on the measurements, the friction factor was estimated from Atkinson's equation and the coefficient of friction from the Moody diagram, and power series and variography were used for computing a fractal dimension for the airway surface. Significant conclusions are reached relating the effect of error in the measurement of cross-sectional and rubbing surface areas of a drift, on the estimated friction factor for the airway. The potential role of the fractal dimension as an alternative to the friction factor for characterizing the roughness of a mine airway is discussed.

Jan 1, 1993

The Hanna Coal & Iron Corp, pilot plant at Randville, Mich , is handling about 250 tons of low grade Michigan core daily Ore is obtained from an ,open pit near the plant Operating alone In the area, the project was first announced about a year ago Construction began June, 1951 and actual testing started about the first of the year A paper presented by Plant Superintendent Elton P Geist at the Upper Peninsula AIME spring technical session, described the plant and outlined the present flow sheet A two-step beneficiation scheme is presently being used It utilizes both flotation and gravity methods After crushing and grinding to 28 mesh, the ore is passed over Humphrey spirals, making a coarse iron concentrate Tailings from the spiral concentrate are then reground and floated to produce iron concentrate and a final tailing Geist stressed that the present flow sheet is tentative and one of several possible variations Testwork is continuing at the plant and future work will determine the method of agglomeration to be used

Jan 1, 1952

Phase equilibria have been determined experimentally for pseudo-ternary sections of the form ?MnO?-(CaO+MgO)-(SiO2+Al2O3) with a fixed Al2O3/SiO2 weight ratio of 0.17 and MgO/CaO weight ratios of 0.25 and 0.17 respectively for temperatures in the range 1473-1673 K. The primary phase fields present for the MgO/CaO weight ratio of 0.17 include manganosite (Mn,Mg,Ca)O; dicalcium silicate a-2(Ca,Mg,Mn)O?SiO2; merwinite 3CaO·(Mg,Mn)O·2SiO2; wollastonite [(Ca,Mg,Mn)O?SiO2]; diopside [(CaO,MgO,MnO,Al2O3)?SiO2]; tridymite (SiO2); tephroite [2(Mn,Mg)O?SiO2]; rhodonite [(Mn,Mg)O?SiO2] and melilite [2CaO?(MgO,MnO,Al2O3)?2(SiO2,Al2O3)]. For the section with MgO/CaO weight ratio of 0.25 the anorthite phase (CaO·Al2O3·2SiO2) is also present. The liquidus temperatures of ferro- and silico-manganese smelting slags have been determined. The liquidus temperatures at low MnO concentrations are shown to be principally dependent on the modified basicity weight ratio (CaO+MgO)/(SiO2+Al2O3).

Jan 1, 2004

By W. J. Wuest, M. J. DeMarco, J. R. Koehler

Yield-pillar-based gate-road designs often fail to provide mine operators with adequate ground control. This is because of the unknowing m is employment of "critically" sized pillars. A "critical” pillar is one that is too large to either yield nonviolently or to yield before the roof and floor sustain permanent damage and is too small to support full abutment loads. To demonstrate the critical pillar concept, afield study of a tapering gate road was conducted by the US Bureau of Mines at the Sunnyside Coal Mines, Sunnyside, UT. Extreme pillar stresses and associated coal bumps characterize the response to first panel mining of a 16.8-m (55.1-ft) wide critical design. Significantly lower pillar stresses, early yielding of the pillar and adjacent panel rib, and an absence of coal bumps suggest that a narrower 12.2-m (40-ft) wide design more closely approaches proper yield pillar dimensions. A probe hole in several 10.6-m (34.8-ft) wide pillars revealed low stress levels and substantial pillar and panel rib yielding prior to abutment onset, indicating a properly functioning yield pillar design.

Jan 1, 1997

By Jena, Anand S, Das R. P

Leaching studies were carried out on Indian Ocean manganese nodules using sulphuric acid as the lixiviant. By leaching the nodules with 8 per cent sulphuric acid for 12h at 100°C, copper and nickel could be completely extracted along with 50 per cent cobalt and 6.2 per cent manganese.94.2 per cent of the iron was also dissolved. To increase manganese and cobalt extraction, charcoal was used as a reductant. The role of charcoal was to reduce the manganese dioxide and render it soluble as manganese sulphate as well as to facilitate solution of the cobalt minerals associated with the manganese dioxide. Various leaching parameters were studied including acid concentration, amount of reductant, leach time, pulp density and leach temperature. It was found that by leaching the nodules with 10 per cent sulphuric acid at 100°C for 4h using 5 wt/wt per cent charcoal (0.05g of charcoal per g of nodule) almost complete extraction of copper, nickel, cobalt and manganese could be achieved. However, under these conditions all the iron present in the nodules was also leached.

Jan 1, 1989

By Achyut Kumar Allady, Praveen Arumughan

NCHRP Synthesis 418 (2011) entitled, “Developing Production Pile Driving Criteria from Test Pile Data” details the occurrence of dichotomy between pile Skin resistance and pile Tip resistance mobilizations at different times for different hammer blows during pile driving operations. With increasing usage of High Strain Dynamic Testing (HSDT) the engineering community started paying more attention to this occurrence of dichotomy resulting in overdriving, pile damage, increased claims, and loss of time. To overcome the dichotomy limitations of HSDT, NCHRP recommends, “the use of superposition to combine the back-calculated tip resistance from a blow on initial drive or from redrive with the back-calculated skin resistance from the early blows at the beginning of restrike”. However, the current practice of external mounted gauges and signal matching for a single blow are unable to evaluate independently the Skin resistance and Tip resistance to achieve the goal of determining the optimum Total Pile Capacity using the superposition. This paper discusses advancements of science and technology with sensors embedded at the pile top and pile tip, the data collected is analyzed by the state-of-the-art FDOT Method to determine Skin and Tip resistances independently for every blow. Independent Tip and Skin resistances each with a Resistance Factor can be summed up to obtain optimum Total Pile Capacity. Additional benefits of determining independent Skin and Tip resistances include obtaining lost skin capacity due to scour, due to pre-drilling/preforming and uplift tension capacity. Furthermore, the benefits of embedded sensors include increased quality control/quality assurance through 100% testing, accelerated construction, life cycle monitoring and asset management.

May 1, 2022

By D. S. DeLong, A. Giza, D. G. Fraser, V. A. Robinson, T. B. Whitmoyer, J. E. Sneckenberger

"A cotton dust animal exposure system has been modified to incorporate a microcomputer feedback loop to monitor particle concentrations. The loop's major components are a minature real-time aerosol monitor (miniram) to estimate concentrations and a microcomputer to read the miniram's data and to control a stepper motor that adjusts the amount of dilutant air mixing with respirable cotton dust. Ninety minute trials of this system indicate that the standard deviation of particle concentrations is within 0.68 Mg/m3 of the average concentration, insuring a near constant concentration of respirable dust throughout the exposure.INTRODUCTION Previous workWeyel et al. (1984) have determined that respirable cotton dust can be shaken from bulk cotton samples using acoustical energy. The particle generator designed to utilize this fact operates like a commercially available sonic sifter, but on a much larger scale.While this generator successfully resuspended trapped respirable cotton dust, the generator output concentration decreased exponentially with time. This disadvantage was solved by Frazer et al. (1986) by operating the generator with a sinusoidal voltage near the minimum resonance frequency of the generator. This adjustment enabled the generator to produce respirable cotton dust for six hours or longer.Frazer et al. (1987) utilized the modified acoustical generator to produce a cotton dust animal exposure system. The cotton dust concentrations were estimated by a miniram, a light scattering aerosol Monitor. The system operator used the miniram values to adjust the system's parameters to maintain the desired concentration level.PurposeThe objective of this study was to introduce a computerized feedback loop to the operator controlled cotton dust animal exposure system. The miniram's estimates were analyzed by a microcomputer to determine what adjustments in the flow of dilutant air were necessary to maintain the desired cotton dust concentration. These modifications were intended to improve system performance and ease the system operator's work burden."

Jan 1, 1988

(The following list contains the names of those members of the Institute of whose connection with military service we have only recently become acquainted; it also includes the names of a few who have recently been promoted or transferred, indicated by a *. A complete list was published in the Year Book, issued as a supplement of the Bulletin for March, 1918.) ANDERSON, AMIL A., Co. A, 309th Regiment Engineers, 84th Div., American E. F., Care Postmaster, New York. ARMSTRONG, HAROLD K., Pilot, Naval Aviation, U. S. Naval Air Station, Miami, Fla. BASSETT, ARTHUR F., Co. 6, -E. 0. T. S., Camp Humphreys, Va. BEDDALL, THOMAS H., Adjutant, 1st Battalion, 1st Gas Regiment, American E. F. BERNARD, CLINTON P., Candidate, 12th Observation Battery, F. A. C. 0. T. S., Camp Taylor, Ky. BROOKE, LIONEL, 50th Co., 13th Battalion, 5th Replacement Engineers, Camp Gordon, Ga. BROWNING, EDWARD, Corp., 1st Regiment Engineers, Co. D, American E. F. BUGBEE, EDWARD E., S. A. T. C. Headquarters, Raleigh N. C. BUTTERFIELD, G. BRUCE, CO. C, 605th Engineers, American E. F. CADOT, J. J., 1st Lieut., U. S. Air Service, American E. F., Care Post- master, New York. CARLOCK, J. B., Major, 2d Battalion, 1st Gas Regiment, American E. F., France.

Jan 12, 1918

By K. J. R. Ford

"Significant advances in mining and metallurgical operations have occurred over the last two decades, to define ore bodies via geological mapping, mineralogical analyses, geostatistical models and resource reserve modeling. Metallurgical process measurement, controls and modeling have also significantly progressed, with advanced instrumentation, control software, data capture systems and simulation tools. This progress together with development of the science of geometallurgy has allowed geologists, mineralogists, miners and metallurgists to start working together to define geometallurgical ore units and link these to mine planning and projected metallurgical performance. However, application of full geometallurgical programs into existing mine-processing operations or into new “greenfield” projects has been slow. This is mainly due to higher costs, limited dedicated technical resources and little or no corporate leadership. Additionally, life-of-mine cash flow models, the “dollars”, have been largely driven by ore tonnage rates, pay-metal grades and fixed pay-metal percentage recoveries, with few or no geometallurgical parameters included.Here defined, the “electrons” represent intrinsic ore characteristics embracing chemical composition, mineralogy, gangue components and their associated fundamental metallurgical processing phenomena. With its ever expanding treasure chest of measurement and modeling tools, geometallurgy paints a much clearer picture of the “electrons” for the geologist and metallurgist. But to fully understand and realize the real net value of ores over the life of a mine, a comprehensive link of “electrons to the dollars” is essential. Intrinsic characteristics of geometallurgical ore units are by definition linked to their metallurgical processing, but importantly need also to be related to operating costs, capital requirements and revenue.This paper discusses this important linkage under topics of ore geology and mineralogy, metallurgical processing, waste disposal, environmental issues, metal refining, project engineering and lifeof- mine models. Topics are illustrated by multi-metal references and by case examples from gold ore heap leaching and manganese ore smelting projects. 1"

Jan 1, 2013

By Birger Schmidt

INTRODUCTION Urban tunneling in soil poses a unique set of problems to planners, designers and contractors. One of the important concerns is the impact of tunneling on the environment: not only the effects of noise, vibrations, construction traffic and surface traffic diversions, but also the effects of ground movements and dewatering on existing structures and facilities. Underpinning or other protection of structures often consume more than 10% of the total construction cost of an urban rapid transit tunnel, and another unknown percentage is expended on construction procedures designed to minimize these environmental effects. Ideally, many basic planning and design decisions should be based on reliable predictions of ground movements due to tunneling. Some of these decisions are: the choice of tunnel alignment and depth to minimize risks and effects of ground movements; selection of schemes to protect existing structures through soil improvement or underpinning, or outright acquisition and possible' demolition; relocation of utilities; selection of procedures for construction monitoring and project control; and the choice of construction and lining methods. To make rational decisions of this nature, the owner and his designers must perform analyses that will balance risks and costs of a variety of alternatives; but to make meaningful risk analyses, they must employ rational methods of predicting ground movements and their effects and must know the reliability of these predictions. Of course, the risk analyses also must consider politics, public relations, insurance and liabilities.

Jan 1, 1974