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By N. O. Johnson

This is one of a series of-Information Circulars dealing with mining and milling methods and costs at mines in various districts in the United States. The Hog Mountain gold mining district is of the northern edge of Tallapoosa County, in the east central part of the State of Alabama. The district is equally close to Goodwater and to Alexander City, both stations on the main line of the Central of Georgia Railroad. From Alexander City the mine is reached by 13 miles of graded road, traveling in a northeast direction. In dry seasons the road is good; in wet weather it is bad but passable. Improvements are being made constantly on the road, so that in the near future the gravel road should be good under all weathered conditions.

Jan 1, 1936

By John Feddock

A recent increase in energy demand has resulted in the rapid growth of coal consumption in the People?s Republic of China (PRC), which is the largest coal producer and consumer in the world. Reportedly, the safety issues in Chinese coal mines have been improving, but the number of fatalities and serious injuries continues to be alarmingly high. The number of fatalities from catastrophic accidents have prompted researchers to review the Chinese mine safety situation and to look for potential solutions. Marshall Miller & Associates, Inc. (MM&A), along with various collaborators, has investigated these issues as part of its work on various projects in the PRC and has discussed the concerns with relevant Chinese officials. Preliminary investigations by MM&A of coal mine accidents during 2001?2006 in the PRC indicate that 65%-78% of the total fatalities were the result of gas explosions and roof falls in underground mines. Even though the drainage of methane has been practiced for decades, current practices do not always produce satisfactory results due to technical constraints and equipment limitations. Based on prior experience of in-seam degasification at the Daning Coal Mine located in Shanxi province, MM&A believes that in-seam directional drilling technology can be a viable solution to degas the low-permeability Chinese coal deposits. This paper 1) reviews current Chinese coal mine safety conditions, 2) analyzes the advantages/disadvantages of current degasification practices in China, and 3) presents the pre-mining degasification practices for the longwall panel at the Daning Coal Mine.

Jan 1, 2007

By Larry R. Powell

The Bureau of Mines, in cooperation with the Illinois Mine Subsidence Insurance Fund, is monitoring the response of two foundations to ground movements induced by subsidence from high extraction mining in southern Illinois. The objectives of the monitoring program are to study the inter- action between the ground surface and a foundation during a subsidence event and to determine the capability of the tiltmeter to detect and monitor subsidence movements. Tiltmeter data were obtained on two foundations constructed near Sesser, IL. One of the 30-by 40- ft foundations was constructed with a typical poured concrete footing, the other with a rein- forced-concrete footing poured on top of pol yethylene sheeting placed over a compacted layer of sand. Soil-filled bins were placed on the perimeters of both foundations to simulate superstructure loads. Monitoring pins and tiltplates were installed on the corners and midpoints of the footing. Additional survey points were established on the five-acre site to track the mining advance. This paper describes the monitoring instrumentation and techniques as they relate to the mining and site conditions. The capability of a tilt- meter to detect and follow the tilt of the foundations is demonstrated.

Jan 1, 1986

By Huw Williams

It is becoming increasingly common practice to re-use existing foundations for new projects, especially on urban sites where geotechnical conditions are congested. A knowledge of the foundation dimensions and capacity is essential for this to take place, however, as-built records are often non-existent. Non-Destructive evaluation (NDE) is now becoming an important tool in assessing old foundation properties and their potential for re-use. Pile dimensions are also critical in the power industry, when they are supporting transmission towers which need to be upgraded, and may carry additional wind loading. This paper describes the application of various NDE techniques that are available and how they can be used to determine pile length, shape and capacity in difficult site conditions, including foundations under structures.

Jan 1, 2006

Interest in the potential use of high-density, thickened tailings has recently increased significantly. Reasons for considering this new technology vary across projects, but commonly include the need to conserve water, perceived lower risk of catastrophic failure, potential easier closure, or even reduced overall costs. As with any new technology, there has been some tendency to overstate its potential benefits. This paper reflects on whether or not the potential benefits that have been attributed to paste and thickened tailings have been realized. Using a grading system, thirteen benefits that were ascribed to the new technology some years ago are evaluated. Data is taken from case studies, and it is suggested that the key proven benefits appear to be reduced operating costs in some cases, reduced wall-building costs, and reductions in water consumption. One key potential benefit that has not been universally achieved is a reduction in the footprint of the tailings facility. Reports in the literature highlight the sometimes confusing nature of trade-off studies. Unless full life-of-mine costs are considered, these studies can be misleading and incorrect. The need to establish a consistent basis for comparative studies is discussed.

Jan 1, 2012

By J. P. Landriault, F. W. Harrison

"Zinc-iron alloy coatings can be produced by either thermally alloying hot-dipped galvanized steel or by electro deposition. Stelco Inc. produces a thermally alloyed Zn-Fe alloy-coated steel, which is mechanically wiped to remove free zinc.A more extensive use of Zn-Fe alloy-coated steel has been predicted for unexposed autobody and structural part applications, since this material is characterized by good spot weldability and formability, and provides superior corrosion resistance under automotive primers.This investigation has examined the coating composition, corrosion resistance, spot weldability and formability of Stelco's Zn-Fe alloy-coated steel and found its properties to be similar to those of Zn-Fe alloy-coated steel produced by post coating annealing.IntroductionRecently, there has been increased automotive interest in galvanneal, which is characterized by good spot weldability, good paintabilityt and good corrosion resistance when primed. Stelco produces a thermally alloyed zinc-iron coated sheet product similar to galvanneal. However, this product is produced by mechanically wiping the free zinc from the surface of hotdip galvanize to expose the underlying zinc-iron alloy.The surface of Stelco zinc-iron alloy-coated sheet is matte gray and has longitudinal streaks which result from contact with Kevlar wipers during production (Fig. I). This paper describes the coating composition, corrosion resistance, weldability, formability and surface appearance of Stelco zinc iron alloy coatings and, wherever possible, compares these properties to those of galvanneal."

Jan 1, 1987

By R. Nendick

"IntroductionThe Ancient Egyptians recovered gold from the mud in the bottom of ponds by having teams of maidens sit around the pond dipping goose feathers dipped in grease into the mud. The gold would preferentially stick to the oily surface and was periodically washed off to give a gold concentrate. This was a forerunner of today's flotation processes.In Greek mythology Jason and the Argonauts pursued the Golden Fleece, which was a primitive form of gravity concentrate produced when gold ore slurry was passed over a sheeps fleece. The heavy gold settled and was caught in the fleece, producing a rich concentrate that allowed Jason & Company to perform the first recorded case of highgrading. The process was a forerunner of todays shuiceboxes used in placer mining.From these simple beginnings, gold metallurgy has progressed to a state where very complex flowsheets are proposed, sometimes to perform a simple metallurgical task. Figure (i) shows a hypothetical flowsheet to identify the range of unit processes that might be brought to bear on a refractory ore. The flowsheet identifies the three primary areas of gold metallurgical operations:Ore PreparationExtractionRecovery."

Jan 1, 1986

By V. Pawlowsky-Glahn, E. Pardo-Igúzquiza, J. J. Egozcue, R. A. Olea

Compositional data constitutes a special class of quantitative measurements involving parts of a whole. The sample space has an algebraic-geometric structure different from that of real-valued data. A subcomposition is a subset of all possible parts. When compositional data values include geographical locations, they are also regionalized variables. In the Earth sciences, geochemical analyses are a common form of regionalized compositional data. Ordinarily, there are measurements only at data locations. Geostatistics has proven to be the standard for spatial estimation of regionalized variables but, in general, the compositional character of the geochemical data has been ignored. This paper presents in detail an application of cokriging for the modelling of compositional data using a method that is consistent with the compositional character of the data. The uncertainty is evaluated by a Monte Carlo procedure. The method is illustrated for the contents of arsenic and iron in groundwaters in Bangladesh, which have the peculiarity of being measured in milligrams per litre, units for which the sum of all parts does not add to a constant. Practical results include maps of estimates of the geochemical elements in the original concentration units, as well as measures of uncertainty, such as the probability that the concentration may exceed a given threshold. Results indicate that probabilities of exceedance in previous studies of the same data are too low.

Jan 1, 2015

By Djavid Mohammad

Over the next several years, the storage capacity of the Metropolitan Water Reclamation District of Greater Chicago?s Tunnel and Reservoir Plan will be increased by 14.8 billion gallons through the addition of two large off-line reservoirs: the McCook and Thornton Reservoirs. The Thornton Reservoir will be constructed at the terminus of Calumet TARP System. The constructed TARP system will be connected to the Thornton Reservoir via connecting tunnels and gates systems. The connecting tunnels will comprise of: an upgradient transition tunnel, steel lined bifurcated tunnel for conveyance and control of flow, downdradient transition tunnel, and energy diffuser at tunnel portal. A large, approximately 250-foot-long, 69-foot-wide, and 40-foot-high, rock cavern will be excavated at an average depth of 320 feet to house the bifurcated tunnel system and associated six large control gates, each 12.5-ft by 28-ft wheel gate. Presented in this article are discussions about the TARP system, the Connecting Tunnels and gates Project, regional rock conditions, evaluation of reservoir?s wall stability for evaluation of tunnel penetration, and design challenges facing during design of the: rock cavern hosting the bifurcated tunnel system and gates and associated tunnels and shaft.

Jan 1, 2008

By Hui Wang

With the great increasing use of nickel metal hydride batteries recently, the waste of this kind batteries have been paid for close consideration. For the main reason that the waste of the batteries contained precious metals and lanthanide which cost great lose. This paper introduces the pyrometallurgical process of recovering nickel and cobalt from the waste of the nickel metal hydride batteries. Particularly, the waste for the process was from factory during the producing program. The use of designed solvent to divide nickel and cobalt in melted state from the waste is described. Also, the result of the nickel and cobalt and melted gangue that mainly consist of lanthanide oxide are included in details. The aim of the paper is to find out a simple and feasible way to reuse waste from nickel metal hydride batteries.

Jan 1, 2009

By C. A. Stetefeldt

FoR the convenience of those who do not care to enter into the details of this long essay, I begin with a summary of the most important results it presents. The extraction of silver by the lixiviation-process from ores which have been subjected to a chloridizing-roasting, is based upon the fact that silver chloride is easily soluble in solutions of sodium or calcium hyposulphite, and that silver is precipitated from such solutions by an alkaline sulphide, with regeneration of the hyposulphite salts. In case the ore contains lead a large portion of the latter is and dissolved, lead sulphate being soluble in hyposulphite solutions. If, at the same time, copper is present, the sulphides precipitated from the solution, contain silver, copper, and lead, a combination of metals not desirable for subsequent treatment. Mr. E. H. Russell, of Park City, Utah, is the inventor and the patentee in the United States and several foreign countries of a new lixiviation-process, based upon the chemical facts discussed in this paper. Mr. Russell has discovered that lead can be completely separated from a sodium hyposulphite solution, as lead carbonate, by sodium carbonate or purified soda-ash, without precipitating any copper or silver. After decanting the solution from the lead carbonate, silver and copper are obtained from it in the usual way. This method of separating lead prohibits the use of calcium poly-sulphide as a precipitant for the sulphides, because any calcium entering the regenerated lixiviationsolution would also be precipitated as a carbonate with the lead by soda-ash. Hence, a sodium sulphide must be employed. A full investigation has demonstrated that this is by no means detrimental. Sodium sulphide and hyposulphite are more advantageously used in the lixiviation-process than the corresponding calcium-salts. Another defect in the lixiviation-process consisted in the necessity of a very perfect chlorination of the silver in the ore, because silver in

Jan 1, 1885

A series of gas inrush events occurred during development at Grosvenor mine resulting in exposure to elevated levels of methane at the production face. A total of 22 gas inrush events occurred releasing between 15 and 130 m3 of methane during each event. The presence of an undrained seam in the immediate floor, geotechnical characteristics of the floor, and the stress environment all contributed to these dynamic floor events, while the geological characteristics of the seam below, such as the seam thickness and ash content of 75%, prevented effective pre-drainage. However, events only occurred in headings mined parallel to the principal horizontal stress direction. In cut-throughs (C/Ts) perpendicular to the principal stress direction, no events occurred, and higher methane levels were observed at the production face.

Jan 7, 2020

By Emad Farouz, Ehab S. Shatnawi

"The increasing demand for small deformations and high-capacity drilled shafts without enlarging drilledshaft diameters has motivated the development and increasing use of a base grouting (BG) technique. This technique has been demonstrated to improve drilled-shaft capacity, especially for shafts tipped into loose cohesionless soils. Nevertheless, there remains considerable uncertainty in predicting the performance of base-grouted shafts, particularly for shafts tipped into cohesive soils. To date, there are only two documented design methods for estimating the axial geotechnical resistance of base-grouted shafts: Tip Capacity Multiplier (TCM) and Axial Capacity Multiplier (ACM) methods. A comprehensive test program was carried out during the design phase of the Wisconsin Zoo Interchange project to help optimize the flyover ramp’s foundation design. The test program included installing and testing one base grouted shaft and one ungrouted shaft at two sites with different ground conditions. Based on test results, it was concluded that prediction of the TCM method is well correlated with the measured values for both cohesive and granular soils; however, both methods tend to underestimate the axial resistance. Results also highlighted the importance of the base-grouting criteria in taking full advantage of the base grouting.INTRODUCTIONBase-grouted drilled shafts (BGDS), also known as post-grouted drilled shafts, consist of conventionally installed drilled shafts that contain access grout tubes placed within the shaft during construction. After installing the drilled shaft and achieving the pre-established concrete strength, grout is injected at the shaft tip through the access grout tubes to improve soil behavior around the drilled-shaft base. The tip grout injection improves the overall shaft capacity and reduces settlement through Densifying the in situ soils, compressing any debris left by the drilling process, preloading the soil beneath the tip to mobilize the shaft base resistance within service limits, increasing the tip area, and increasing the side resistance in the lower portion of the shaft."

Jan 1, 2016

By David E. Nicholson

The Bureau of Mines has constructed a special compression chamber for developing stress-strain relationships of mine backfill and simulating the high compressive ground pressures encountered in underground mines. A one-dimensional, or Earth-Pressure-at-Rest model is proposed for backfills subjected to these pressures. Results of the compression tests performed in the chamber indicate that reliable stress-strain relationships can be developed from these tests. The primary objective of the test series was to evaluate the effectiveness of compaction of common backfills in retarding ground closure. Analysis of the stress-strain data shows an eightfold reduction in relative strain in optimum well-graded, compacted backfills over poorly graded, loose backfill material. Analysis of the one-dimensional compression test data also indicates a significant retardation of transmitted stress in dense compacted samples of backfill and natural sands. Although not fully understood, a deformation mechanism is thought to occur at the intergranular contacts in cyclic fashion causing frictional heat loss and a reduction in transmitted stresses in the densely packed materials. The experimental values of transmitted stress are compared with theoretical values of effective stress calculated from the one-dimensional compression relationships developed by Hendron (4).3 These experimental values of transmitted stress compare very closely with the theoretical values of effective stress.

Jan 1, 1968

By C. J. Bise, D. A. Poukhovski

Two integral components of the 30 CFR 48 training requirements mandated for new miners, newly employed experienced miners, and the annual refresher training of all miners are hazard recognition and prevention of accidents. In these categories, instruction shall include the recognition and avoidance of hazards present in the mine, and a review of accidents and their causes. Unlike instruction preparation for fact-based material, program development for hazard recognition places a particular challenge before safety-training specialists because they are often limited in their ability to adequately gauge the trainees' levels awareness prior to training. Further, they must also assure that the training is relevant, and it is presented in a thought-provoking manner. Computer-based instruction is particularly well suited for assisting trainers in developing hazard- recognition topics because it can be used in pre-training and post-training modes for assessment of training effectiveness, in addition to use as a presentation tool. Therefore, this paper will present a recent approach developed at Penn State to apply this technology for assessment and instruction of accident prevention through hazard recognition, with an application prepared for surface coal mines.

Feb 24, 1997

My selection of the Australian coal industry as the theme of this Presidential Address arose from the fact that it is one of our most important mineral industries. The industry is presently prospering.M.ore coal, mostly of better quality (except for certarn power-house types), is being produced more cheaply in terms of real money than at any time in the past, and exports overseas are currently at a highlevel.In. spite of this, concern has been expressed in certam quarters about the future of some phases of the industry; for example, there has been some public comment on the selling price of our coking coal to Japan, the possible over-export of our coking coals from New South Wales, the introduction of foreign capital to develop large-scale mining ventures in Queensland, and the proposed export of substantial quantities of coking coal from the same State.Furthermore, proposals for the introduction of atomic power plants into several States well endowed with reserves of coal have given rise to comment, and recently the Department of National Development(1968) warned that insufficient attention is being paid to "orderly development and careful husbanding of the nation's coal.To reach a balanced judgment on whether these views are well founded it is essential to make a broad survey of the present position of the coal industry in the Australian economy. I therefore propose to deal briefly with several aspects, and to comment, in particular, on the important subjects of exploration and research in progress at present on Australian coals.Detailed descriptions of the Australian coalfields are to be found in existing technical publications (e.g.. Andrew, 1965; McLeod, 1965) and the data on coal reserves have been progressively revised as more accurate information has become available. In New South Wales detailed knowledge of the coal reserVes is limited to under 20 per cent of the sur...

Jan 1, 1969

By M Wilson, D Whiteman, P Kuiper, S Talu, G Watt, A van As

Once the draw process has begun in a block cave, it is very difficult to identify which regions of the cave have successfully propagated, where the caved material is flowing from and where it is flowing to. The uncertainty around cave flow increases as the cave is drawn and can be further compounded by poor draw control practices. These uncertainties make it difficult to plan effective draw strategies to control dilution, as flow model predictions tend to gradually diverge from the actual state of the cave. There have been documented occasions where observed caving phenomena, such as muck pile surface rilling, could not be reproduced with the cave flow models of the time. The ultimate consequence of cave flow uncertainty is generally manifest as higher dilution and lower grades.In order to measure the real-time flow of caved material within an active block cave, CRC Mining and Elexon have developed, together with Rio Tinto, a cave flow monitoring system called Cave Tracker, which is being trialled at Argyle Diamond Mine (ADM) in Western Australia. The Cave Tracker system at ADM comprises electronic ‘beacons’ that have been installed down long HQ diameter drill holes located above the extraction level. As the cave-back propagates and the rock mass fragments, beacons are released into the muck pile and flow along with the caved material to the drawpoints below. At Argyle, the beacons are configured to emit a signal every three days. These signals are picked up by detectors installed on the extraction and undercut levels, allowing the positions of the beacons to be determined.By examining the real-time material flow in different regions of the cave, flow mechanisms can be better defined. Draw control strategies can then be actively tailored to manage the current state of the cave. Thus, previously undetectable indications of excessive rilling, rapid cave propagation, cave stall, air gaps and dilution entry can now be identified early and assessed continuously as the cave progresses. For the first time it is possible to amend draw strategies based on measurements from inside and outside of the fractured zones, allowing caves to be managed more effectively.CITATION:Whiteman, D, Talu, S, Wilson, M, Watt, G, Van As, A and Kuiper, P, 2016. Cave Tracker flow monitoring system installation at Argyle Diamond Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 479–488 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By J. Asfahani

"The Schlumberger configuration used in geoelectrical sounding is slightly adapted here to obtain reliable data for both shallow and deep penetration depths from the same survey. In this configuration, two kinds of current electrode half-spacings are used: the first enables construction of vertical electrical resistivity sounding (VES) curves for shallow depths (<50 m), and the second for depths =250 m. For a given VES location, two field curves are measured and interpreted using two standard approaches. Practical characteristics of such a modified configuration are illustrated with two field applications in Syria. The first aims to characterize the structure of Quaternary and recent deposits in the Al-Ghab depression region, and the second deals with exploration for phosphatic sedimentary units in the Al-Sharquieh mine. La configuration de Schlumberger normalement employée dans les levés géoélectriques a été légèrement modifiée afin d’obtenir des données fiables à faible et forte profondeur durant le même levé. Dans cette nouvelle configuration, deux types de demi-espacements des électrodes sont utilisés : le premier permet le développement de courbes de sondage de résistivité électrique verticales (REV) pour les faibles profondeurs (<50 m), et le second atteint des profondeurs =250 m. Pour une localité REV donnée, deux courbes de champs sont donc mesurées et interprétées grâce à deux approches standardisées. Les caractéristiques pratiques de cette configuration modifiée sont illustrées par deus exemples d’application en Syrie. Le premier vise la caractérisation de la structure des dépôts Quaternaires et récents de la région de la dépression d’Al-Ghab, et le second traite de l’exploration pour des unités phosphatiques sédimentaires à la mine Al-Sharquieh."

Jan 1, 2009

Flotation Performance Improvement by Air Recovery Optimisation on Roughers and Scavengers

Sep 13, 2010

By H. E. Grier, H. H. Aronson, H. F. Coffer

"Nuclear explosions are currently being planned for use in oil and gas production, the recovery of oil from oil shale, gas storage and copper leaching. The current status of each of these projects is discussed, with emphasis on the economics of each application. The first commercial application of nuclear explosives will be in gas stimulation. Project Gasbuggy will be rapidly followed by two additional shots, also related to gas production. These three events, each in a different formation, will be described in this paper with a discussion on their significance to the world's oil and gas industry. The use of nuclear explosives in oil and gas stimulation should be a standard accepted practice within a few years. Calculations based on explosions in media such as tuff, alluvium, granite and dolomite predict large increases in productivity when nuclear devices are used in tight, thick formations. The broken-up rock resulting from the explosion becomes the new well bore, with a production rate of six to twelve times that of a normally completed well.Also included in the paper is a discussion of the real or possible problems associated with nuclear explosive engineering. The only major foreseeable problem is the seismic shock wave. This limits the size of explosive which can be used near important surface structures. A discussion is included on the radiation problem, which we believe to be largely psychological in the case of contained explosions."

Jan 1, 1968