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By Hae-Moon Choi, Sang-Don Lee, Chang-Ha Ryu

The purpose of the study presented in this article is to establish a standard blast pattern to yield optimum blasting performance along with an attempt to reduce a difference between design and construction. A series of test blasts were carried out at two tunneling sites of Central Inland Highway crossing in Korea. Long-hole blasting was tested in rock mass whose RMR value is over 60.The blasting results were evaluated by measuring degree of fragmentation, advance rate,muckpile distribution, overbreak, etc. Based on the results of test blast, several patterns were proposed for a two-lane highway tunnel.

Jan 1, 2006

By John C. Machisak

THE INJURY data and related employment experience of the coking industry in the United States for 1955 arc presented in this publication under the following general sections: (A) General Injury experience: Tables 1 to 9: Contain current and comparable data on operating statistics, number and classification of injuries, injury-frequency rates, and accident agencies involved in causing injuries. Data are tabulated for the industry as a whole, for each typo of oven: and for the States in which coke is produced.

Jan 1, 1958

By J. Haynes

Coal mines in the eastern US often use sloped shafts as production beltways for ore removal, as means of access for supplies, and for ventilation. These structures are usually completed with the help of a contractor. In late 2011, Frontier-Kemper Constructors was engaged to build a slope for a coal mine in southern Indiana. Although the site was located in familiar Illinois basin formations, the geology proved to be very difficult. This paper describes some of the challenges faced during excavation of this slope and the methods used to overcome them, including changing the method from conventional drill and blast to cutting with a continuous miner.

Feb 27, 2013

By A. Golshani, M. Oda, K. Suzuki, T. Takemura

Anisotropic behaviours of OhshimaOshima granite were investigated by carrying out uniaxial compression tests, together with observations of microcracks under an optical microscope. The elastic modulus tensor of Oshima granite at 10 per cent strength,E10, were calculated using theoretically formulation of elastic modulus tensor in terms of the second-rank crack tensor for pre-existing open microcracks. Furthermore, with the assumption of orthorhombic elasticity, the nine moduli of Oshima granite E10were determined by uniaxial compression test. Twenty-onemoduli of samples, calculated without assuming any symmetry, also showed orthorhombic features. Direction of the symmetry axes agreed well with the orientation of preexisting cracks. Comparison of crack tensor-based formulation results with the experimentally determined one show that the anisotropy of elasticity of Oshima granite is caused by pre-existing open microcracks, not by pre-existing healed microcracks and also crack tensor formulation can be used, as a first-order approximation at least, to describe the anisotropy of Oshima granite induced by pre-existing open microcracks. ZUSAMMENFASSUNG: Das anisotrope Verhalten des Oshima-Granits wurde mit Hilfe voneinachsigen Kompressionstests und durch die Betrachtung von Mikrorissen unter einem optischenLichtmikroskop untersucht. Das Elastizitätsmodul von Oshima-Granit bei 10 Prozent Kraft E10wurde berechnet, indem man die Formulierung des Elastizitätsmodultensors, ausgedrückt alsRisstensor zweiter Ordnung theoretisch auf bereits existierende Mikrorisse angewandt hat.Außerdem wurden die neun Module des Oshima-Granits unter der Annahme orthorhombischerElastizität E10mit einem einachsigen Kompressionstest bestimmt. Einundzwanzig Stichproben,die ohne die Annahme irgendeiner Symmetrie genommen wurden, zeigten ebenfallsorthorhombische Merkmale. Die Richtung der Symmetrieachsen stimmte mit der Orientierungbereits vorhandener Risse überein. Der Vergleich der Ergebnisse der auf dem Risstensorbasierenden Formulierung mit der experimentell bestimmten Formulierung zeigt, dass dieAnisotropie der Elastizität von Oshima-Granit von bereits vorhandenen offenen Mikrorissenverursacht wird, und nicht von vorhandenen vernarbten Mikrorissen, und dass dieRisstensorformulierung auch zumindest für eine Annäherung erster Ordnung benutzt werdenkann, um die durch vorhandene offene Mikrorisse induzierte Anisotropie des Oshima-Granits zubeschreiben. RESUME: Les comportements anisotropes du granit d’Oshima ont été étudiés en réalisant destests de compression simple, et en observant les microfissures au microscope optique. Le tenseurdu module d’élasticité du granit d’Oshima sous une résistance de 10 pourcents, E10, a été calculéen se servant de la formule théorique du tenseur de module d’élasticité basé sur le tenseur defissures de second ordre des microfissures ouvertes préexistantes. En outre, sur base del’hypothèse de l’élasticité orthorhombique, les neuf modules du granit d’Oshima ont étédéterminés par des tests de compression simple. Vingt et un modules d’échantillons, calculés endehors de toute hypothèse de symétrie, ont aussi montré des caractéristiques orthorhombiques. Ladirection des axes de symétrie correspondait bien à l’orientation des fissures préexistantes. Lacomparaison des résultats de la formule basée sur le tenseur de fissures avec les résultatsdéterminés expérimentalement montrent que l’anisotropie de l’élasticité du granit d’Oshimaprovient des microfissures ouvertes préexistantes, et non de microfissures préexistantes referméeset que la formule du tenseur de fissures peut servir, au moins comme première approximation, àdécrire l’anisotropie du granit d’Oshima marqué par des microfissures ouvertes préexistantes.

Jan 1, 2003

By Douglas M. Smith, G. A. Maki

"The initial development of the massive potash deposits of the prairie evaporite formation took place over a decade ending in 1970. The potash mining and refining facility near Rocanvi11e, Saskatchewan was the 1ast of ten mines to come into production during that era. This operation, known as Sylvite of Canada Ltd., was designed to produce 1. 2 million short tons per year of KCl product in granular, coarse, standard and special standard grades.In 1977 the parent company, Hudson Bay Mining and Smelting, sold the Sylvite property to the Potash Corporation of Saskatchewan. Shortly thereafter PCS slated its new Rocanville Division for a two phase program of expansion. The first phase, completed in the spring of 1979, was relatively small, involving mill debottlenecking and additional equipment in the compaction circuit and the product and ore storage areas. The second phase was a major undertaking which included additional mining equipment and a new 300 STPH milling circuit. This work was completed during the fall of 1981 and has increased the Rocanville Division's nameplate capacity to two million STPY.Thickening equipment operating in the Saskatchewan potash industry is generally situated within the main refinery building or a separate insulated and heated structure due to the harsh winter climate and the need to closely control plant brine temperatures to ensure good flotation circuit performance. Since these thickeners process large volumes of slurries, conventional basin type designs tend to be large, ranging up to 150 feet in diameter or more. As part of the general effort to minimize capital costs, the potash industry has begun investigating the use of alternate high capacity, compact thickener designs. In this regard, PCS Rocanville undertook a program in 1978 to evaluate a Lamella™ Thickener and one other type of 'High Rate' thickener* as alternatives to a conventional design for the phase two expansion project."

Jan 1, 1983

By Lawrence C. Schneider

In the past decade regulations governing the manufacture, distribution, storage, and use of explosives have proliferated. These laws have been developed by a host of federal agencies with no coordination. The result has been contradictory and impractical standards, which once adopted, are resistant to change or repeal. The current OSHA standards are one example which is examined in detail. The Commonwealth of Kentucky has made progress in modifying these standards, and still providing protection to the blaster and the public.

Jan 1, 1981

By G. Hames, A. Drake, B. Sampson

The Timbarra opencut gold mine is located about 30 km(19 miles) southeast of Tenterfield in northern NSW some 4 hours by car from Brisbane, the capital city of Queensland in Australia. It was a small operation designed to produce about 40000 ounces of gold per annum utilising contract mining and company owned crushing plant feeding heap leach pads. This is a standard setup except that the mine owner was in charge of all aspects of drill & blast design even though a contract drilling & blasting (shotfiring) service was being provided. The major problem was that the blasting operations were yielding massive amounts of oversize due to the jointed partially weathered nature of the granite. This was adversely affecting all downstream aspects of the operation as well reducing gold output as ore boulders were being dozed over the side of the mine as they were impinging on mining productivity. The oversize problem had to be solved as the mine was struggling to achieve design gold output. Significant design & trialing effort using minesite resources were utilised to reduce the oversize but this failed even when powder factors up to 1kg/bcm(1.68lb/yd) were used. Dyno Consult from Dyno Nobel were therefore called to investigate, review & trial options to reduce oversize from the top flitch.

Jan 1, 2003

By C. T. Holland

Coal mining has been an important industry in the Appalachian area for many years. This is particularly true in the northern part of the area, namely, in Pennsylvania, West Virginia, and Ohio. Also, in the south a great deal of mining activity has been carried on in Alabama, Kentucky, and southwest Virginia. Some of the by-products of this activity has been the production of mineralized water from the mines in copious quantitites. The southern Appalachians have been somewhat more fortunate in that the water there has had a considerable amount of alkalinity in it, which has to a large extent eliminated some of the more undesirable aspects of mine drainage. Northern Appalachia, including central and western Pennsylvania, the Monongahela basin in West Virginia, and the Appalachian area in eastern Ohio have not been so fortunate in that coals in those areas and the top and bottom rock have, in many cases, shown considerable quantities of pyrite, and the water does not carry the carbonates found farther south.

Jan 1, 1969

By Meredith Scaggs, Emily Sarver, Lucas Rojas Mendoza

"Early on Jan. 9, 2014, approximately 37,800 L (10,000 gal) of crude 4-methylcyclohexanemethanol (MCHM) leaked from a storage tank sitting on the bank of the Elk River near Charleston, WV (WVDEP, 2014; CSB, 2014). MCHM is a chemical commonly used in preparation of fine coal and is considered nonhazardous in terms of transportation, storage regulations and also toxicity (CDC, 2014a). Freedom Industries Inc., a producer and vendor of specialty chemical products, had acquired the storage facility from Etowah River Terminal, LLC just a few weeks prior in December 2013 (WVDEP, 2014; Freedom, 2005). The direct cause of the spill was ultimately determined to be two small holes in the base of the 76-year-old tank, which were created due to corrosion damage (Bauerlein and McWhirter, 2014).The spill site was located a little more than 1.6 km (1 mile) upstream from the intake of a municipal water treatment facility operated by West Virginia American Water (WVAW), which serves a population of 300,000 across nine counties in central West Virginia (CDC, 2014a). In a matter of hours, the leaked MCHM made its way through the treatment facility and into the water of nearby homes and businesses, where its strong smell was noticed almost immediately. On the evening of the spill, WVAW concluded that its conventional treatment processes, which include carbon filters to remove a variety of contaminants from water, were not capable of fully removing the MCHM and a "Do Not Use" order was issued for all customers (WVAW, 2014a).With little information readily available regarding the potential human health effects of MCHM, the U.S. Centers for Disease Control and Prevention (CDC) quickly issued an advisory ruling that set a maximum screening level of 1 ppm for safe drinking water (CDC, 2014a). Based on this recommendation, the "Do Not Use" order remained in effect for a total of eight days, until Jan. 17, when the WVAW distribution water was confirmed to have MCHM concentrations below the approved level (WVAW, 2014a). However, due to the pungent odor of the chemical, its presence was still recognizable in the WVAW facility and in consumers’ tap water after the order was lifted (Manuel, 2014). Recent studies have shown that the chemical can be detected in water at sub-ppb concentrations, a fact that undoubtedly added to growing public concern (Rosen et al., 2014; Gallagher et al., 2014). In response to numerous complaints and demands, WVAW continued flushing the treatment facility and pipes until Feb. 25 when MCHM levels were measured below 2 ppb (WVAW, 2014b), and eventually replaced the affected filter media (WVAW, 2014c)."

Jan 1, 2014

By R. S. Olson

An analysis of the wash thickener-two stage filtration circuit was undertaken to quantitatively describe the circuit performance. On the basis of information developed in this study, the factors of major importance in reducing soluble loss are: filter wash, wash zone size, filter capacity, filter feed pulp dilution, blow back, filter cloth, water to repulp, water to primary wash, water to feed pulp and thickener underflow. The wash thickener-two stage filtration circuit has been used in many hydrometallurgical plants to separate solute from leach solids. As many as 20 to 30 plant operating variables determine the performance of the wash circuit and hence the soluble loss. The complex relationships of these variables, with each other and with soluble loss, make the evaluation of their effect on mill performance difficult. An analysis of this type of circuit was undertaken to quantitatively describe the circuit performance. THE CIRCUIT The diagram in Fig. 1 represents the operation of the wash thickener-two stage filter circuit. This circuit provides for counter current, cross current or for a combination of countercurrent-cross current operation. The feed pulp stream, J, is intended to include any solution or water, other than primary and secondary filtrate, which enters the wash thickener. Except for filter washing, the operations in the circuit are simple mixing operations which can be described by material balance. The concentration of solute in the filtrate and cake solution after application of wash liquor cannot be described by simple material balance. The displacement washing equation, derived by Rhodes1 and extended by Choundhury and Dahlstrom,2 appears to best describe this case of miscible displacement in porous media. In a useful form, it is

Jan 1, 1963

By Wei Sun, Jaewon Choung, Zhenghe Xu, Zhangming Cui

"High intensity conditioning has been demonstrated in a number of cases to enhance fine particle flotation. The improvement could be attributed to the enhanced formation of particle aggregates. However, the understanding of aggregation mechanisms remains rather limited. Recently, an enhanced particle aggregation was observed by the formation of small air bubbles resulting from high intensity agitations (HIA). In this study, a novel visualization system is designed and constructed for characterizing the fine bubbles formed in an HIA cell. The new design allows determination of gas evolution and bubble size distribution. With this system, the effect of dissolved air on fine bubble generation by HIA is investigated. The results show that HIA creates a favorable environment for the formation of gas nuclei and small size bubbles due to hydrodynamic cavitation.INTRODUCTIONFlotation is a dominant separation technique employed by mineral industry to recover the valuable mineral particles. However, in general, particles finer than approximately 10 µm are not effectively recovered by conventional froth flotation technique due to their low inertia and high specific surface area (Fuerstenau, 1988). Therefore, the fine particle flotation has been considered as the central challenge of flotation research. Substantial advances have been made for fine particle flotation from both a theoretical and technological point of view (Fuerstenau et al., 1979; Song and Lu, 1990; Subrahmanyam and Forssberg, 1990; Sivamohan, 1990; Sedat and Barry, 1991; Matis, 1995). High intensity agitation (HIA), for example, has found some success to improve fine particle flotation kinetics in laboratory tests (Chen et al., 1999a and 1999b; Valderrama and Rubio, 1998; Rubio and De Brum, 1994).The effect of mechanical agitation on flotation kinetics has been recognized for many years. In mid-1970s, Warren (1975) reported that increasing the shear rate of the pulp could improve the efficiency of ultra fine particle flotation. He attributed this improvement in flotation to the formation of aggregates. This concept of aggregation has been extended by Rubio (1978), and Bulatovic and Salter (1989), who employed high intensity agitation (HIA) method to promote aggregation. They found that HIA with the addition of collectors, frothers and suitable modifiers significantly improved both the flotation recovery and selectivity of ultra fine sulphide minerals. The improvement was explained by warren’s shear flocculation theory. Till now, many studies (Chen et al., 1999a and 1999b; Valderrama and Rubio, 1998) have been undertaken to improve fine particle flotation by HIA. However, most of these studies were focused on the relation between energy input and flotation efficiency. Less information was available for describing how the aggregate formed during HIA process."

Jan 1, 2006

By R. F. Hinds

A pressurizing system was designed and built to apply a radial pressure of 5.000 psi to rock samples. Samples of the Bradford, Weir and Kirkwood sandstones were subjected to radial pressures parallel and perpendicular to the bedding in the system and the changes in conductivity, porosity and permeability were deter-mined. Asymptotic decreases in conductivity, porosity and Klinkenberg permeability were observed over the 0- to 3,500-psi range. From these data, the increase of formation factor over the same range was calculated. The cementation exponent expressed in the Archie equation was found to increase with pressu,re. The rate of change varied from formation to formation. Only small differences were observed for samples taken parallel to the bedding as comnared to those taken perpendicular to it except for the Bradford sand. Above 3,500 psi the data are not good enough to tell if the properties continue to fall-off asymptotically or in a different manner. A possible explanation for the probable litnit of the asymptotic rate around 3,500 to 4,500 psi is that this represents the maximum pressure which the formations have unrdergone during their geological life as a result of burial. INTRODUCTION For many years measurements have been made in the laboratory of the properties of oil-bearing sandstones with little consideration being given to whether these properties had been changed when the samples were moved from their original position in the ground to the laboratory. Relatively little has been reported in the literature on the effect of pressure on the properties of sandstones. The changes in permeability for eight typical consolidated oil-bearing sandstone samples with overburden pressure (0- to 15,000-psi range) was presented by Fatt and Davis' in graphical form. In 1953 Fatt' also reported the relationship between porosity and overburden pressure for four typical consolidated oil-bearing sandstone samples (0- to 5,000-psi range). Fatt later described the changes of formation factor and porosity of 20 typical oil-bearing sandstone samples with overburden pressure changes (0- to 5,000-psi range) giving the values of the coefficients and exponents in the Archie' equation, and the more general Winsauer equation', where C, k and m are empirical constants, F is the formation factor, and + is the porosity. During the experiments of this investigation the core was contained in a neoprene rubber sleeve as shown in Fig. 1. It was held between two steel end members which were mounted in a steel cylinder. The unassembled pressure cylinder with its component parts is shown in Fig. 2. The core was insulated from the two steel end members by a Teflon sleeve with a small hole in the

By Swapan Bhattacharya

United States federal and state regulatory authorities require underground mine operators to adopt adequate measures to minimize material damage to the surface caused by nine subsidence. This paper presents an approach to define and determine the extent of material damage due to subsidence from underground coal mining. The basic steps involved in the development of adequate criteria have been enumerated together with the approaches and methodologies used.

Jan 1, 1984

By J D. St George

In this paper a laboratory investigation into the effect of confining stress, water content and gas desorption on coal permeability is presented. Of major significance is the effect of coal permeability on outburst occurrence and methane production, which is influenced by changes in stress. Test results indicated that the shrinkage of the coal matrix associated with desorption is greater than the coal matrix compressibility which will cause a reduction in the effective stress, hence increasing coal permeability.

Jan 1, 1998

By K. M. Kolin

ABSTRACT OF ORAL PRESENTATION A discussion of current U. S. Bureau of Mines research into the problem of strata control in multiple Western coal seams will be presented. The problem and research priorities will be described as determined from interviews with major Colorado and Utah mine operators as well as governmental agencies responsible for Federal leases. Proposed contract research and ongoing in-house studies will be discussed, including case histories and results from projects being conducted at two multiple seam operations in Utah.

Jan 1, 1977

By Hubert E. Risser

Although, for about a half-century the percentage of coal production provided through strip mining has steadily increased, recent trends indicate that a peak in percentage (not tonnage) is being approached, principally because of the decline in economic adrantage enjoyed by strip mining compared to underground mining. Factors contributing to the decline are the decrease in the margin of advantage in manpower requirements held by strip mining; an increase in depth and volume of overhurden, requiring larger equipment and capital investment; increasing lack of reserve land blocks large enough to support extensive strip mining operations; more stringent legislation for reclamation of stripped land, with increasingly higher costs of such reclamation; and the increasing costs of land surface rights for strip mining. Already there has been a peak and suhsequent decline in relative importance of strip mining insome major Eastern coal-producing states; trends indicate that a peaking for the whole Eastern region is on the way. Although, in the West the pressures are less severe, they will, nevertheless, reduce to an increasing degree the advantage that strip mining has possessed. For about half a century, strip mining has been providing an ever-increasing share of total coal output in the United States, and in the past 30 years this share has grown from less than 8% to 33.7%, as shown in Fig. 1. Fig. 1 also shows that strip mining is gaining faster in the West than in the East. From 1961 to 1967, output from strip mines grew 63.6 million toqs, or 52.2%. Certainly there is nothing in such performance to indicate any peaking in the level of strip coal-mine production. But the fact is that, if not in actual tonnage, strip mining appears to be reaching its peak in relative importance, at least east of the Mississippi River. And the area east of the Mississippi provides 90.0% of the strip and 94.9% of the total coal production of the nation. The relative economic advantage which spurred strip mining's growth for a third of a century has been diminishing markedly in recent years. Fig. 2 shows evidence of this decline. From 1947 until 1961, strip tonnage output remained fairly stable, at the end of the period showing only a 12.5% decline. Meanwhile, underground coal production fell 44.5%. As the result of the greater decline in underground coal, strip coal in 1961 furnished 30.3% of the total coal produced, compared to only 22.1% in 1947. In the succeeding six years, however, underground coal output increased by 76.5 million tons, while strip output increased only 63.6 million. Further evidence of the strengthening of underground coal's relative position — or if you will, the weakening of strip coal's position — can be found in the major coal stripping states: Illinois, West Kentucky, Ohio, Pennsylvania, Indiana, and West Virginia, which in 1966 provided 80% of the nation's strip coal. Fig. 3 shows what has been happening in three states lying in the Appalachian field and in the total output of these three states. In the figure, the column height represents the output of coal mined by all methods. The number at the base of each column is the percentage mined by stripping. In Pennsylvania and Ohio, the percentage of strip mining increased between 1956 and 1961, but by 1966 had declined from the 1961 level. In West Virginia, a decline occurred during the first five years but was followed by a rise. In January 1968, Coal Age published an article listing the locations and capacities of new large mines in the planning and construction stages that would be operating by 1968-1971. The plans for West Virginia and Pennsylvania indicated all the new mines would be underground. Except to the extent they might replace existing under-

Jan 1, 1970

By P M. Black, T Itaya

Arc-type volcanic activity has been a major feature of the late Cenozoic geological evolution of the Pacific-Australian plate boundary in the northernNew Zealand region. The time/space distribution patterns of arc-type rocks reflect changes in the nature of the plate boundary as it has evolved. Inception of volcanism began in the north during earliest Miocene times (26 Ma) following ophiolite emplacement and during the next 10 Ma developed into a volcanic arc segment extending south to the present position of the central North Island. The northern part of the arc became extinct about 15Ma ago, but activity continued in the central (Coromandel) part of the arc until about 5 Ma ago. In late Pliocene and Quaternary times volcanic activity has become concentrated in a northeast trending zone which is collinear with the Tonga-Kermadec Arc.   These time/space patterns can be interpreted in two ways. Firstly, if relative plate motion was essentially transform in the region prior to 26 Ma then a small change in the relative plate vectors may have initiated subduction and the associated volcanism. Southward evolution of the arc can then be seen as the straightening and extension of a single arc. Alternatively, the distribution of volcanic rocks can be interpreted as the capture of a relatively short lived arc by southward migration of the dominant Tonga-Kermadec subduction system.

Jan 1, 1995

By W. C. Lacy

This article is a progress report of a program designed to quantitatively evaluate geological parameters to predict stable slope angles. The author feels that, although there does not appear to be any one technique or characteristics that will suffice as an index to the determination of stable slope angles, a combination of seismic methods as outlined here, detailed geological mapping and logging of core, and a better understanding of the angle of internal friction in rock types will permit accurate estimation. A mining engineer friend once remarked, "If we don't have pit slope failures, the slopes are too flat." Since economic justification of an open pit project is based upon ultimate pit slopes, we cannot wait until the pit is developed and slopes established by trial and error. Some combination of geological and/or geophysical techniques must be developed to permit accurate prediction of stable slope angles and to suggest modification of pit outlines to result in slopes enabling maximum economic yield. This presentation is a progress report of a program designed to quantitatively evaluate geological parameters to predict stable slope angles. The principle of the weakest link applies to any slope stability evaluation and necessitates detailed geological examination and recording of observations. Physical failure will occur along any surface where shearing stress exceeds shearing resistance. Rock conditions are seldom uniform even within a single cut or pit face, so stability conditions will vary. Consequently, both plan outline and ultimate slope limits must be tailored to the specific situation. Economic advantages to be gained by slight increases in slope angles in deep pits are well recognized and stimulate efforts to obtain maximum permissible slope angles. MECHANICS OF SLOPE FAILURE Excellent reviews on the nature of slope failure have been presented+2,6,8,11 For the purpose of this study, the writer considers failure to take place by one or more of three processes: 1) ravelling, 2) translation or slope failure, and 3) rotation or base failure (Fig. 1). The effects of increased pore water pressure in soils were recognized in 1923 by Terzaghi in his development of the concept of effective stress, and he has applied the same principle to jointed rocks designating water pressure as cleft-water pressure.8 Cleft-water pressure in a rock slope reduces normal pressure on the plane of failure, thus reducing shearing resistance and resulting in slope failure. In the following discussion it is assumed that adequate drainage is supplied to prevent any build-up of water pressure. This is the first step in any program to establish maximum slopes. Ravelling: Ravelling occurs in rocks with low cohesion and entails the free movement of individual fragments ranging from single rock falls to running ground. Removal of lateral support wherever slope angle exceeds the angle of repose of the rock parti-

Jan 1, 1963

How Particles Stick to Bubbles - The Influence of pH and Hydrophobicity in Flotation

Sep 13, 2010

By L G. B Wadley

The Australian gold industry has made large steps forward in the last few years. This progress has been driven by improvements in mining and processing technology, the high price of gold and by a favourable legislative, political and taxation environment. This paper concentrates on improvements in gold project development, process engineering and technology as seen by BHP Engineering, Perth, Australia. The paper describes technical aspects of successful gold project development including metallurgical test work, feasibility studies, choice of process flow sheet (gravity, heap leach, carbon in pulp (CIP), carbon in leach (CIL) or other routes). It sets out our views on plant design, plant construction, procurement and project management. A case study for a small plant recently completed in the Philippines is presented as a solution to the problems often encountered in treating quartz vein gold deposits.

Jan 1, 1990