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By Robert V. Price

It is a pleasure to be here today to discuss coal's prospects with the Society of Mining Engineers of AIMS--- a group destined to play a crucial role in shaping our national energy future. Much has been said lately about attaining domestic energy self-sufficiency, but to date, little has been done. Oil tankers from Venezuela and Kuwait continue to glide across the seas to meet our incremental energy needs. Meanwhile, our principal domestic energy resources -- oil and natural gas reserves in the Outer Continental Shelf and the oil shale deposits and the coal lands of the West -remain untapped. Help, however, appears to be on the way. In a forceful address last fall, President Ford called for the elimination of oil as a fuel for base-loaded power plants and its replacement with coal by 1980. He also urged the accelerated leasing of federal lands on the Outer Continental Shelf, the resumption of coal leasing on federal lands, and the development of a new energy conservation policy. There are, of course, many details left to be worked out. Language must be developed to put statutory flesh on the conceptual bones spelled out by the President. Congress must act. Regulations must be approved and tested, if need be, in court.

Jan 1, 1975

By Seong-Taek Lim

Recently, 7xxx aluminum alloys have been evolved into new variants for thick semiproducts which have low amount of 2nd phases and low quench sensitivity. Commercial 7xxx alloys, especially in the thick forgings made of big ingots, often entail microstructural inhomogeneities and concurrent poor mechanical properties due to limited heating ranges and slower quench cooling. In this study, high strength aluminum alloy 7175 and 7050 are adjusted as an attempt to control the equilibrium phases (M-, T- and S-phase) to have optimum microstructure for the thick forging applications. The effects of the relative content of (Zn, Mg, Cu) on the evolutions of the coarse equilibrium phases, hardening response and resultant mechanical properties are investigated. Equilibrium phases (M,T,S) are evolved depending on the constitutional effect, primarily the change of Zn:Mg ratio, and cooling rate following solutionizing. The formation of the T- and S-phases is effectively controlled, and M-phases are homogeneously precipitated in the adjusted (dilute and high Zn:Mg ratio) alloys. It provides extended heating range and lower quench sensitivity than conventional alloys. The attempts ensure the microstructural homogeneity and improved properties, and is expected to be uniquely applicable in 7xxx thick forgings.

Jan 1, 2004

By Robert B. Scott

The Dents Run Demonstration Project near Morgantown, West Virginia, was a cooperative venture involving the U.S. Environmental Protection Agency (EPA), the Water Resources Division (WRD)(1) of the West Virginia Department of Natural Resources (DNR), and the Christopher Division of the Consolidation Coal Company (CONSOL). The object of this project was to demonstrate pollution control methods and to clean up a 37.8 sq km (14.6 sq mi) watershed severely polluted by coal mine drainage. A study entitled, "Water Infiltration Control to Achieve Mine Water Pollution Control" (EPA-R-2-73-142),(2) was conducted by the Cyrus Wm. Rico Division of NUS Corporation for the grantee to determine the feasibility of utilizing remedial techniques to improve the Dents Run water¬shed. This study showed that the Dents Run watershed was discharging as much as 6,870 kg/day (15,100 lb/day) of acid; 1620 kg/day (3,560 lb/day) of iron 17,250 kg/day (38,000 lb/day) of sulfates; and 29,500 kg/day (64,900 lb/day) of total dissolved solids into the Monongahela River near Morgantown, West Virginia. This pollution was caused by the combination of borehole pump discharges from active underground mines, runoff from abandoned strip mines, and runoff from refuse dumps.

Jan 1, 1977

By S. Kashani-Nejad

The kinetics of the thermal decomposition of samples of Mg2(OH)3Cl.2H2O that were obtained by a novel leaching technique applied to a commercial magnesium electrolysis feed were investigated under ambient atmosphere. Thermogravimetric (TG) Analysis showed that decomposition of Mg2(OH)3Cl.2H2O exhibited a single intermediate stage wherein crystalline water was lost at roughly 108 °C. Conversion of the resulting Mg2(OH)3Cl to MgO, HCl and 1120 occurred at temperatures above 398 °C. Thermal decomposition of anhydrous Mg2(OH)3Cl was seen to be consist of two stages. Both stages exhibit first order kinetics with respect to the weight percent of Mg2(OH)3Cl remaining in the sample. However, the rates of decomposition in the two stages were significantly different. Detailed analysis of the kinetic data suggested that the rate of decomposition of Mg2(OH)3C1 was controlled by the rate of removal of the gases released. The change in decomposition rate during the course of the experiments was explained by HCI being released in stage 1 and followed by release of H2O in stage 2.

Jan 1, 2004

New Copper Deposit in Chile. - The recent copper discovery in Chile, made jointly by U.S.-owned Empresa Minera Utah de Chile, Inc., and Getty Mining Chile), Inc., awaits the passage of Chilean legislation which is expected to govern the terms of new foreign investment in the country's mining sector. Named La Escondida, the discovery is reported to have the potential for producing 100,000 tons of refined copper per year. This compares with Chile's total refined primary copper production in 1980 of 811,000 metric tons, and to U.S. refined primary production in 1980 of 1,122,000 metric tons derived from domestic material, and 89,000 metric tons from foreign material. U.S. Firms Buy Chilean Properties. - A bid of $18.1 million, made jointly by Chevron and St. Joe Minerals Corp., won over competing bids for the purchase of the Libra and Mena gold-silver-copper deposits in northern Chile. Chevron is the lead partner and owns 70% of the venture. The two properties purchased have not been developed to any significant extent. They are located near St. Joe's El Indio gold-silver-copper mine. The venture is also looking at the possible purchase of two other mines in the area.

Jan 1, 1981

By Yuhsuke Mizukami

Crude high Cr containing steel such as tool steel, heat-resistant steel or stainless steel is produced by dissolution of high carbon ferro-chromium into molten crude steel. In the refining process, decarburization is performed at the first stage, and deoxidation is followed in the next stage. Therefore, the equilibrium relation between dissolved Cr and 0 in molten Fe-Cr alloy after decarburization is very important when yield of deoxidizer is considered for the ovemll control and optimization of the process. It is well known that the yield of deoxidizer does strongly depend on the kinds of refractories of furnace in the secondary refining process. In the present work, the equilibrium relation between dissolved Cr and O in molten Fe-Cr alloy has been measured in a Cr2O3, MgO or Al2O3 crucible at steelmaking temperature. O contents at given Fe-Cr components have been lower in order of Cr2O3, Al2O3 and MgO crucible. The present results have been discussed based on the activities of the constituents in pure solid Cr2O3, and FeO-Cr2O3, MgO Cr2O3 and (AI,Cr)2O3 solid solutions.

Jan 1, 2003

By E. Lee

The behavior of As bioleaching using Acidithiobacillus thiooxidans (A. thiooxidans) in mine tailings containing highly concentrated As contents (i.e., As=33877 mg/kg) was systematically evaluated according to the changes in temperature (25?40°C, pulp density=0.5%, pH=1.8), pulp density (0.5?4%, temp=30°C, pH=1.8), and initial pH(1.8?2.2, temp=30°C, pulp density=0.5%). The changes in temperature and pulp density affected the As leaching behavior more than the change in initial pH did. Based on the pH and oxidation-reduction potential (ORP) results, the As leaching was attributed to solution acidification. In particular, As leaching was accelerated with increasing sulfate production in the reacting solution. After bioleaching, surface of tailings examined that many pores which dissolved As were formed by a chemical reaction due to bacteria. The As bioleaching efficiency by A. thiooxidans was enhanced by the oxidation of both the added elemental sulfur and the sulfur compounds in the mine tailings. The As bioleaching efficiency was maximized at 50.5% under conditions of an initial pH of 2.2, reaction temperature of 30°C, and pulp density of 0.5%.

Feb 23, 2014

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By R. Maurice King

In the operation of today's large scale ore-processing mills, it is extremely important to have some way of making an objective evalu¬ation of the performance of the available flotation reagents. Attempts to do this may often result in inconclusive findings since the magnitude of the difference in the mill results for any two reagents is apt to be quite small compared to the variability introduced by the process and 'the analytical procedures used to measure them. In cases where two reagents give vastly; different mill results, evaluation becomes a simple matter and as such deserves no further attention here. A question of primary concern, however, is how a mill can go about evaluating the performance of two reagents which may, for example, give a difference of only 0.001% copper in the-tailings or of 0.2% in copper recovery. The casual observer may feel that such small differences may be of little importance, but in a mill-whose daily tonnage is between 30 and 40 thousand, these differences could mean a substantial savings. Before the presentation of an actual example of a reagent testing scheme designed for just this-purpose, perhaps a few minutes should be devoted to a review of some statistical methodology to be used later in the discussion.

Jan 1, 1964

By Man-Chao He

One of the critical problems involved in deep coalmines is unusual gas emissions. Many researchers agree that there is a relationship between coal gas emissions and geological features such as tectonics or geological disturbances, gas content, properties of the coal and rock and the mininginduced stress state in the coal seam and rock. Thus, the present paper intends to investigate complex mechanical phenomena during the process of gas emission in underground coal-mines. A program of laboratory testing was undertaken to study the effects of temperature and pressure on mechanisms of gas emission. It must be noted that this paper describes new techniques developed to simultaneously measure deformation and gas pressure, as well as flux during the test, taking the characteristics of gas transport into consideration under certain temperature and pressure conditions. The results indicate that under certain temperature and pressure conditions, gases adsorbed to coal start to desorb, and increase the pore pressure. High pressure gases entering coal fractures can generate high tensile stresses near the crack tips, leading to crack propagation and coalescence, which in turn can cause the specimen to dilate. From the experimental viewpoint, these test results may help us discern why mining seismic events can trigger gas emissions.

Aug 1, 2013

By Long Meng, Kuiyuan Chen, Zhe Wang, Yiwei Zhong, Zhancheng Guo

Printed circuit boards (PCBs) contain plenty of toxic substances as well as valuable metals (e.g. Pb and Sn). In this study, supergravity as a novel technology was used to separate and recover different mass ratios (Pb/Sn) of Pb-Sn alloys from PCBs. In a supergravity field, liquid metal phase can permeate from the solid particles, and based on this, 200, 280 and 400 °C were selected to separate Pb and Sn from PCBs. The results showed that the gravity coefficient only affected the Pb-Sn alloy weight, and did not change the mass ratio of Pb/Sn. With the increase of gravity coefficient, the recovery values of Pb and Sn were increased. In the separation process, under the gravity coefficient of 1000 and separation time of 2 min, the recovery values of Pb were 33.13, 38.86 and 50.48% at the temperature of 200, 280 and 400 °C, respectively, and the recovery values of Sn were 23.31, 32.57, and 40.81%, respectively, and the mass ratios of Pb/Sn in the Pb-Sn alloys were 0.55, 0.40 and 0.64, respectively. This provided a new approach to recycle Pb and Sn from PCBs.

Mar 1, 2018

By DAVID F. McFARLAND

THE making of courses of study and curricula has long held first place as the favorite pastime of educators. As a game, this activity is as fascinating to some as golf or bridge, 'and the golfer's hope of a low score is matched by the teacher's ambition to some day evolve a sequence of studies that shall prove the ideal preparation for a life of maximum service and, profit. There are few in, this gathering who have not tried their skill at this game and still fewer are those who have been long satisfied by the product of their efforts. A curriculum is hardly printed in the college catalog before conditions arise which seem to make changes desirable, and strong will power is needed to maintain the program long enough to give it a fair trial. Metallurgical curricula are not less subject to change than others, 'and; indeed they have seemed, at times, to change more rapidly than other curricula because of the changing 'needs of the industries and the demand that the graduate be trained to meet the new conditions. Metallurgical practice is constantly proving that "time makes ancient good uncouth," and the graduate metallurgist is required to adapt himself to newer and

Jan 1, 1930

By Debra Satkowiak, Ronald Thomas

The Institute of Makers of Explosives (IME), a non-profit safety and security organization founded in 1913, is known for its industry best practices, Safety Library Publications (SLP), some of which have been incorporated into rules by regulatory agencies. The IME developed the first commercial storage, quantity distance (Q/D) table titled “The American Table of Distances” (ATD). It was developed by IME’s legacy association in 1910 and was originally based on observations of structural damage from 117 accidental explosions involving small to very large amounts of explosives, primarily dynamite and black powder. In 1930, the IME published a book, compiled by Ralph Assheton, called the “History of Explosions on Which the American Table of Distances was Based”. The distance in feet in the ATD were founded on the measurements at which inhabited buildings sustained substantial structural damage from the accidental detonation of explosives. For example, minor damage such as window glass breakage and the “shaking down” of plaster was not considered substantial structural damage. Other damage to property that was readily repairable was also not considered “substantial.” It was concluded that unless some integral portion of the building was damaged, the occupants would not be subjected to serious risks.

Jan 1, 2017

By M.P. ROY, ASHISH K. VISHWAKARMA, A.K. MISHRA, P.K. SINGH, VIVEK K. HIMANSHU

Principal component analysis (PCA) is one of the dimension reduction techniques widely used to classify data based on features. Ground vibration is a major hazard arising from rock blasting operations, and accurate prediction of the vibration is necessary for designing controlled blasting parameters. Most of the widely accepted predictors of ground vibration consider the maximum explosive charge weight per delay (MCPD) and distance as the parameters responsible for ground vibration, but mining sites with bigger production targets have varying geometrical parameters to suit the excavator utility. Accordingly, other blast design parameters will also have impacts on ground-vibration intensity. A blast vibration predictor considering all the blast design parameters would be complicated, and some of the parameters will have overlapping contributions to ground-vibration intensity. Data classification using PCA is a feasible solution, and regression analysis may be performed to develop predictors using the classified input data. In this study, PCA was used along with multivariate logarithmic regression to predict ground vibration, and the performance of this technique to predict ground vibration was compared with the performances of various existing empirical predictors. The evaluation suggests that the predictor with logarithmic regression followed by PCA performs better than the existing empirical predictors.

Nov 1, 2022

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989

By J. P. Ulery

As a result of several recent methane/dust ignitions in surface auger and highwall mines, the U.S. Bureau of Mines investigated the occurrence of methane gas at these operations. Three mine sites were visited in western Kentucky and one in western Pennsylvania to collect run-of-mine coal samples for gas content determination using the modified-direct-method (MOM). Results indicate the samples emitted small quantities of methane, carbon dioxide, and nitrogen. Either methane or nitrogen was the predominant gas released. The same gases were released after crushing the samples for residual gas content; however, nitrogen was the primary component of this fraction. Total ~as contents ranged from less than 0.01 cm /g to 0.54 cm3/g. The hydrocarbon gases probably originated during coalification. Other gases may have originated partially as a byproduct of coalification and partially as a result of other, near-surface processes. The data suggest that although methane quantities are small, desorption could occur at near surface conditions prior to mining. The desorbed methane could accumulate as a free gas in fractures in the coal bed or roof rock. When these fractures are penetrated by the auger, methane could rapidly enter the whole atmosphere possibly creating explosive conditions.

Jan 1, 1994

By G. Atesok

Turkey?s EU affairs started in 1963 with the Ankara Treaty. On 31 December 1995 the Customs Union between Turkey and the European Union came into effect. In order to achieve the Copenhagen Criteria?s, Turkey, made laws parallel to the Framework Programs. On 3 October 2005, with the confirmation of ?Membership Framework Document? the negotiation process of Turkey has started. Coal had important role in the industrialization of EU and it is directly related to Energy and Environmental subjects. In this point many restriction became with the some protocols, in last decades. European Union composed Energy and Coal Policy, therefore engaged to reduce the emissions, and made new regulations. This regulations concern Turkey?s energy future, since large; but low quality of lignite reserves of Turkey, it is expected to have some difficulties with Union?s Environmental Legislation during Turkey?s congruity process. With the last natural gas import agreements of Turkey, the production and consumption of coal sunk in last seven years. However, considering environmental sustainability, the role of coal in energy production will rise up in the coming future. In this paper, in terms of Turkey Energy Sector, production and consumption problems of coal discussed and evaluated considering EU?s coal, energy and environmental rudiments.

Jan 1, 2014

By J. V. Batty

In the course of the investigation of manganese mineral occurrences in the United States, Bureau of Mines examining engineers collected several lots of ore from the Black Rock, Kramer, and. Morgan-Cromar properties, Tooele and Juab Counties, Utah. Extensive laboratory tests were made to determine the amenability of the ores to standard ore-dressing methods of concentration. The Black Rock claims 1 and 2 are 42 miles northwest of Jericho, Tooele County, Utah. A. J. Huber of Salt Lake City and Ross Rydalch of Tooele, Utah, are the owners. The deposit-is reported to be a definite manganese fissure vein in quartzite along which considerable shearing and cross fracturing have occurred. Laboratory work was conducted on a 2-ton sample of run-of-mine ore procured by a Bureau of Mines examining engineer and two smaller, higher-grade samples submitted by the owners as a result of later development. The Kramer deposit is described as a bed of manganese oxides in quartz. The property is being worked by L. E. Kramer, Tooele, Utah, and is 41 miles northwest of Jericho) Tooele County, Utah, approximately 1 mile north of the Tooele-Juab County line. A 1-ton run-of-mine sample was submitted for testing by the examining engineer.

Jan 1, 1952

By Manuel Gomez

A lignite from Milam County, Tex., has been oxidized by air at temperatures from about 27° to 300° C. for varying lengths of time. The oxidized coal was carbonized at 500° C. in a laboratory assay unit, and the products of carbonization were measured and analyzed. The data presented suggest that, as lignite is progressively oxidized, tar yields are decreased and gas yields are increased in a ratio approximating 1:1. It is surmised that tar-yielding structures in the nonoxidized coal produce gas, principally, when the coal is oxidized. Char-yielding structures of the nonoxidized coal give rise to additional water of decomposition after oxidation and pyrolysis. As lignite is subjected to greater oxidation, the gaseous product evolved on pyrolysis becomes almost entirely carbon dioxide. Tar yields decrease with an increased degree of oxidation, so that the reduction in tar yield may be used as a qualitative measure of oxidation. Pilot-plant drying and carbonization, where air is used as the transport gas and where some air is included in the drying and carbonizing gases, induces some oxidation of the coal particle. The short residence time in a fluidized system with reference to the oxidation environment limits the oxidation.

Jan 1, 1956

By Tiruvengala Padma, Nilesh Naik

Piles are common type of deep foundation elements used for the special bridges, transmission towers, Jetties, and tall structures. Lateral loads on the structures can be due to either earth pressures, wind, waves, impact, moving vehicles and eccentric application of axial loads or in combination of the loads. Hence the lateral capacity of piles plays a major role in determining the pile dimensions. The laterally loaded pile analysis is a soil-structure interaction problem as the lateral capacity of pile depends on the soil strength and stiffness parameters and its reaction to the lateral load on pile. The common approach to determine the lateral load analysis of piles is the Beam on Lateral Springs Method also known as “p-y” method. In this method the pile is modelled as a beam and supporting soil is modelled as lateral springs. This study is focused on the comparison of output obtained from three geotechnical softwares namely FB-MultiPier, L- Pile and Wallap. L-Pile Software is based on Finite Difference Method, Wallap on Horizontal Subgrade Modulus Method and FB MultiPier on Finite Element Method. Pile response in terms of deflection, shear force and bending moments under vertical and horizontal loads from above three software are compared and concluded.

Sep 1, 2022