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By Diana Drinkwater

As ore grades decline, ore deposits get harder and mineralogical complexity increases, metallurgical skills are more important than ever to ensure that today?s mining operations are operating efficiently and profitably. Yet specialist undergraduate degree programs have all but disappeared and metallurgical skills training for graduate engineers in the workspace if often haphazard. In response to this situation, specialists at the JK Centre in Queensland, Australia, have put together a professional development program designed to fast-track skills development for early career metallurgical professionals. The program, called ?MetSkill ® ?, is offered as a group training package for young metallurgists in the workplace. It is centred on a meaningful technical investigation negotiated between the JK Centre delivery team and the client company. As well as learning about project management and data collection and analysis, the participants study specialist topics such as comminution, flotation and mineralogy under the tutelage of senior research and consulting professionals. The technical investigation provides an opportunity for immediate practice of these new skills and JK Centre specialists are on hand to provide feedback and support throughout the program. The participants are employed across different operations in Australia and the Asia-Pacific, and although they occasionally come together for group training activities they are often separated by considerable distance. Specialist educational professionals from The University of Queensland have provided an innovative web platform to support collaboration and communication between all participants. This paper will describe the MetSkill ® program in detail, as well as providing a report on its initial roll-out to 2 groups of Australian graduate metallurgists in 2012

Sep 1, 2012

By Anoush Ebrahimi

Mining dilution is one of the most important factors affecting the economy of mining projects. Ore losses and dilution are present at all stages of mining and while several models can investigate the influence of dilution it is its quantification that poses the most serious challenge (Pakalnis et al., 1995). This paper introduces a methodology to quantify dilution factor in open pit mines. The proposed approach makes use of general mining software available in most mining companies. Therefore it is amenable to most mining operations and provides a readily available tool for understanding mining dilution for operators and consultants. To illustrate the methodology the author uses an example from a hypothetical mine. Dilution increases the operating costs in the mill by increasing the tonnage of material to be milled. In addition to its direct impact on short term income of a mine, dilution causes significant changes in other factors that on the long term reduce the overall value of the project. For example, it prolongs the mine life by reducing mill?s effective capacity. It also reduces the feed grade. In most cases, lower feed grade means lower mill recovery. Dilution also increases the cut-off grade which in turn reduces the overall ore utilization of a mine. In some cases, to take advantage of economies of scale, mining operations tend to plan for higher mining rates. Moving to a larger scale of operation means less selectivity, hence more dilution. This is true for all kind of deposits. High level and uncontrolled dilution may ultimately defeat the purpose of increasing production rates. If not impossible in theory it is nevertheless extremely difficult and expensive to eliminate dilution in practice. Some amount of dilution is practically unavoidable in most mining operations (Scoble and Moss, 1994). Although completely avoiding dilution may be impossible, we can measure and control it. By better understanding the root causes of the dilution and planning accordingly, it can be controlled and reduced. While we do our best to identify and calculate all the other cost items of a project, no matter how small, it is common to make general assumptions about dilution instead of quantifying it. It is common to assume a general dilution such as 5% for massive deposits and 10% for tabular shape deposits. While these figures may be a good starting point in early stages of mining studies, it does not take in to consideration the complexity of the problem. Dilution factor varies within a single mine for different benches and zones. This is due to changes we see in grade distribution and shape of ore body. It also varies based on commodity price. It is necessary to make sure that these variations are taken into account when designing or evaluating a mine. Dilution varies in different mines based on the deposit characteristics, operational aspects and economic cut-off grade. For instance, shape of the deposit, bench height, equipment size, and market conditions will have an impact on the level of dilution in a mine. It is paramount for mining projects to have a better understanding of dilution right from the beginning. In times like today, where mining operations must operate at peak efficiency, it is even more crucial to be able to calculate and have a better grasp of all the parameters influencing the economics of a project including dilution. In order to produce better project evaluations, dilution studies should be an integral part of any project.

Aug 1, 2013

By B Klein

This paper stems from research and development in sensor and sorting technologies towards future sustainable mining undertaken by the UBC Mine-Mill Integration group in collaboration with MineSense Ltd. Sensors and sensor-based technologies such as ore telemetry and sorting are envisioned to be a significant component in achieving such ‘invisible’ future sustainable mining. Such technologies offer high flexibility and power in use: delivering valuable information from the very preliminary stages of mining exploration through to final upgrading of the ore preceding the fine comminution stages. This paper reviews sensors and sorting as enabling technologies towards a future smart mining operation and introduces a model in which sensor-based exploration (down-the-hole sensing), ore exploitation (smart-shovels), transportation (smart-conveyors) and preconcentration (sensor-based sorters) are effectively integrated to increase the present value of operations. It is anticipated on the basis of several case studies that an effective use of sensor technologies through tomorrow’s ‘smart mine model’ should lead to several positive impacts ranging from increased mining production, to reductions in transport costs, overall energy use and waste generation. In this way sensors can be used to maximise the profitability and present value of the mining operation from the exploration stage through to mine closure.

Nov 22, 2011

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized- bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could be incorporated in design, installation, and operation to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized- bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on heated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or "bumps" had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By H. A. Schrecengost

Information presented herein was gathered by examination of 29 fluidized-bed thermal coal dryers and by conferences with manufacturers and users of such equipment to determine what safety features could b incorporated in design, installation, and op ration to minimize fire and explosion hazards. Fire and explosion hazards are inherent in certain types of coal dryers in that high temperatures are employed; the sizes and volatility of material handled are capable of propagating explosions; and drying gases are seldom, if ever, low enough in oxygen content to prevent ignitions of dust clouds, distilled gases, or their combinations. This is especially true for fluidized-bed dryers in which the coal is dried in air suspension and in which atmospheric air is constantly introduced to temper the heated furnace gases. Occurrence of fires on hated bedplates, in dust collectors, and in hot gas inlets was common in nearly all the dryers examined. Forceful explosions which produced external effects had occurred in 11 (39 percent), and internal "puffs" or ?bumps? had occurred in at least 24 (79 percent) of the plants examined in the study.

Jan 1, 1965

By P J. Handley

"Predicting how coal seams will be beneficiated through the coal handling processing plant (CHPP) has long been challenging within BHP Coal. Various coal seams from different areas are mined and stockpiled separately, often depending upon a deleterious coal quality parameter; high/low trace elements for example. These stockpiles are then fed in different ratios into the CHPP to produce the desired product/s. In understanding the washability characteristics of the feed source, mine geologists and process engineers work together to improve the beneficiation of different coal materials through the CHPP.For the majority of the BHP Coal deposits, the washability data is available for the coal seams across the deposits. However, no previous standardised modelling and prediction technique existed that could ensure the correct information was available for forecasting and refining CHPP processes. This paper will discuss the steps undertaken to implement a geometallurgical prediction tool that simplified and streamlined the washability modelling and yield estimation process. The value realised to the BHP Coal assets resulting from this process was: improved compliance to plan increased throughput increased CHPP recovery through improved efficiencies and increased revenues.CITATION:Handley, P J, 2017. Washability modelling and estimation techniques used to improve coal handling preparation plant beneficiation, in Proceedings Tenth International Mining Geology Conference 2017, pp 327–336 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

By Bernardo Martins Braga

A prática de inertização de um distribuidor de 17,7 t para lingotamento contínuo de aços foi estudada numericamente através de um modelo matemático tridimensional não-isotérmico. O modelo considera uma única fase gasosa composta de dois componentes: argônio e ar. A turbulência foi levada em conta por meio do modelo k-e padrão. Os cálculos foram executados utilizando o software de CFD comercial ANSYS CFX. Diferentes configurações do sistema de inertização foram simuladas. Os resultados indicaram que a configuração atual é ineficiente e novas configurações foram sugeridas. Algumas recomendações para a correta prática de inertização também são fornecidas.

Jul 30, 2018

By M. Ralchenko, C. Samson, M. Svilans, C. Walsh

"Through-the-Earth (TTE) radio has been proposed as a means of emergency communications in mines. The propagation of a TTE radio signal depends chiefly on the subsurface conductivity distribution. Robust forward models of signal propagation can be computed based on a realistic conductivity estimate. These models can be used, for example, to optimize frequency, estimate signal range, identify zones of anomalously strong or weak signals, or to optimize the position of the above-ground TTE radio unit. A method was developed to determine the conductivity distribution of a mine overburden using TTE radio transmission data. At multiple locations in an underground test mine, we recorded a wideband electromagnetic signal, spanning a frequency range of approximately 500 to 8,500 Hz, transmitted from a vertical magnetic dipole at the surface. Using a finite-difference time-domain forward modeling code, a layered Earth conductivity model that accounts for topography was fitted to the observed data, which minimizes the difference between the calculated and observed attenuations for each transmitter-receiver pair, for each frequency of interest. Introduction and objectiveThrough-the-Earth (TTE) radio has been proposed for emergency underground communications. The most common type of TTE radio is based on the transmission and reception of signals by electromagnetic induction. These signals are in the extremely low to very low frequency range — in practice, between 400 and 9,000 Hz. This technology was historically developed for mine safety, although recently other applications have been suggested, such as communications in civilian infrastructure like high-rise buildings or tunnels, in the military, and even for wireless detonation and activation. In a coal mine, which is a setting of particular importance for TTE radio due to the higher risk of accidents, day-to-day communications can be done through a wired link. High-frequency line-ofsight systems, whose signals cannot penetrate rock, are also used for communications from nonfixed points. Another option is a leaky feeder system, which is a permutation of a line-ofsight system and a wired link, where a partially shielded coaxial cable allows the signal to “leak” (Delogne, 1982). In an incident such as a mine collapse or explosion, a TTE radio system can still provide a communication link, as wired systems can be severed, and line-ofsight systems cannot penetrate through collapsed portions of the mine, or to the surface (Forooshani et al., 2013; Yarkan et al., 2009)."

Jan 7, 2018

By Roberto L. Romero

The dressing of Bolivian tin ores has been done up to the present by classical. gravity methods, taking advantage of the high specific gravity of cassiterite compared with that of the accompanying gangue. For this purpose, jigs and shaking tables are used in the treatment of the various size fractions in which the ore is classified. Bolivian ores are mainly of the vein type and, to obtain a reasonable separation, crushing and several stages of grinding are necessary during the process to substantially liberate the cassiterite from the gangue. Gravity processes for cassiterite are effective for sizes down to 200 mesh. Below this size the efficiency of the gravity methods falls off very rapidly with increasing fineness of the mineral grains. The conventional treatment for this material is desliming followed by tabling on shaking tables various other types of machines have been designed for the gravity treatment of these fine particles but they have had limited success. Bolivian ores contain an appreciable amount of minus 200 mesh material constituted by "primary fines" caning from the mine itself, and "secondary fines" originated during the crushing and grinding necessary for liberation of the difficulty in the treatment of these fine particles is one of the causes why the recovery of tin in concentrates is only of around 50% in the mines owned by Corporacidn Minera de Bolivia, the State owned enterprise. The average figure for other Bolivian mines is

Jan 1, 1971

By C. T. Baroch

This report summarizes cost data accumulated during 15 months of sustained operation of the Bureau of Mines Boulder City (Nev.) titanium plant, which had a capacity of about 1,350 pounds of titanium sponge per day. The plant was constructed during the 1952 fiscal year with funds supplied by the Ordnance Corps, Department of the Army. Its original purpose was to engage in process development work as a continuing phase of the Bureau of Mines policy to seek improvements in producing titanium metal. In early 1953 the Defense Materials Procurement Agency contracted with the Bureau of Mines for producing approximately one-half million pounds of usable ductile titanium sponge. Production began in May 1953, ended in September 1954, and yielded 492,503 pounds of acceptable metal. Operating costs covering this period of operation, with suggested depreciation and administrative costs, are given, as well as outlines of building and equipment capital costs. In addition, miscellaneous economic considerations are discussed, including labor and operating-time schedules.

Jan 1, 1956

By D S. Perera, P Wal, D C. Southam, J L. Lowe

The Cooperative Research Centre for Sustainable Resource Processing (CSRP) is undertaking a large research project involving partners from industry, universities and government, which aims to develop the necessary chemical and structural understanding of geopolymer materials made from waste products for them to be used to capture a significant market share of the concrete business for a given industrial region. We are investigating the suitability of a range of soluble silica-bearing waste streams for use as geopolymer concrete feedstocks. In order to utilise a variety of waste streams, either singly or blended, an understanding of the role of secondary metal ions (Fe, Ca, Mg, Ti, etc) in the geopolymerisation process is essential. A range of experimental and analytical techniques is therefore being used to better understand the structure-chemistry-property relationships of geopolymers. Currently, we are investigating geopolymers made from a variety of waste streams (fly ash, kaolinite, red mud, etc) available in the Kwinana Industrial Region, Western Australia. This paper will detail how the basic scientific research underpinning the project is vital if waste streams of varying composition are to be successfully used in a commercial concrete product and the regional synergies required to develop geopolymers from waste streams.

Jan 1, 2006

By Richard H. Mote, W. C. Schroeder

The endlessly changing pattern of mineral supply and demand offers opportunity to the alert and can bring disaster to the unwary. The discovery of ore bodies, the invention of extractive processes, the provision of new transport facilities, the political stabilization of underdeveloped areas, and many other changes can increase supply dramatically. Such new outpourings of mineral wealth from ore bodies bring fortunes to their developers, and consumers frequently find their competitive positions decidedly improved by new and cheap sources of supply. On the other hand, operators of marginal properties can find competition from newly opened high-grade mines intolerable. Consumers that have depended on the products of nearby, high-cost mines may find new, remote, low-cost supplies advantageous only to their competitors. The invention of new prospecting methods can have spectacular effects. Shortly after World War I the discovery rate of petroleum pools began to decline. The leading prospecting technique of that day, the projection downward of surface reflections of geologic structure, was proving less rewarding. Prophets foretold an oil shortage in the near future. But at that very moment scientists were perfecting the application of seismic waves to reveal underground oil-bearing geologic structures. As these geophysical methods were put into commercial use the whole outlook changed-the problem of the 1930's became how to cope with the surplus from discovery, not how to meet the ever rising demand. Many lead mines were being abandoned as unprofitable about this same time because the penalties charged by smelters for the zinc in the ores and concentrates more than counterbalanced the payments for lead and silver. Then selective flotation (at the time called differential flotation) appeared,

Jan 1, 1959

W. S. GRESLEY, Erie, Pa. (communication to the Secretary): A six-entry method of opening coal-mines is, or was a short time ago, practiced in the Connellsville coal-region; but Dr. Chance's method has a novel aspect; for while in the Connellsville region the main pillars are formed outside of two pairs

Jan 1, 1901

By MARCELS CHLUMBER

BY the term making an "electrical log" the authors designate an operation conceived for the purpose of determining electrically the characters of formations traversed in drilling, the determination being carried out by means of measuring the electrical resistivities of the rocks along the uncased portions of drill-holes. As in the case of an ordinary core record, this process connotes a geological studs of the strata, and for that reason it is given a similar designation. The paper is divided into three parts, of which the first deals with the resistivities of rocks in general, since it is through this electrical parameter that they are to be characterized. The second deals with the technique, and the third with the description of practical applications of the electrical logs.

Jan 1, 1929

By Tignor E. M.

The Brenneman oil field in Grant District, Hancock County, W. VA., was selected for study by Bureau of Mines engineers because it was typical of many of the smaller petroleum reservoirs in the Appalachian region. In 1906, E. W. Marland & Co. discovered the Brenneman field by drilling a well that readied the oil-bearing .Berea sandstone at a depth of 750 feet and initially produced 200 barrels of oil a day. Most of the oil-productive area (348 acres) of the field was developed in a comparatively short time, and the initial daily production rates of some of the wells were as high as 1,000 barrels of oil a day. Although the field was a prolific producer of oil for several years, it was abandoned in 1923 when the production rate was less than 1,000 barrels of oil a year and 705,000 barrels of oil had been produced. Secondary-recovery operations were started in the Brenneman field in 1927 after useable old wells had been repaired and unsatisfactory wells had been plugged; drilling of new wells was started in 1929. The peak of the redevelopment program was reached in 1942 when 92 oil-producing wells and 26 injection wells were in use; both air And mixtures of air and natural gas were used for injection purposes. It is estimated that approximately 357,000 barrels of oil, equivalent to 1,030 barrels per acre, 105 barrels per acre-foot, 8.5 percent of the total pore volume, or 11.9 percent of the original oil in place will be produced as a result of gas-injection secondary-recovery operations. Engineers of the Bureau of Mines Petroleum Field Office, Franklin, Pa., are studying secondary-recovery projects in the Appalachian region as a part, of the Bureau's secondary recovery research and are reporting these studies so that others: can profit by the experience gained from the operations. In common with most of the other Appalachian oil fields, there was no natural water drive in the Brenneman field. The estimated oil saturation in the Brenneman reservoir at the end of economic gas-injection operation indicates that additional oil might be recovered economically by water flooding and that a pilot flood would be warranted.

Jan 1, 1950

By Jack A. Caldwell

"This paper describes the nature of stage curves and the ways in which they have been used to study the construction sequencing of tailings impoundments. They provide a simple graphical method of representing the main aspects of an impoundment, studying the effects of different impoundment geometries, and predicting and controlling impoundment operations.IntroductionThe designer o f a tailings impoundment must, at all stages of design, examine the relations hip between the volume o r tones of tailings that will be deposited at the impoundment, the height to which the tailings will rise in a given time and that rate at which the various parts of an impoundment will be constructed. The operator, if he is to keep proper control of this impoundment, must be able to examine the effect of different deposit ion rates at the impoundment, and the consequences of placing more or less tailings at different parts of the impoundment. The operator must be able to see at a glance just how much higher an impoundment will be at the end o f the following yea r of deposition, and this he must be able to do in order to formulate his annual construction and operating plans.Stage curves are the best way o f modeling an impoundment. The simple impoundment model represented by the stage curves enables the designer and operator visually to examine the relationships between the various factors, such as impoundment volume, deposition rat e and construction rate, that dictate the essential features o f impoundment design and operation.A design model for a tailings impoundment may be formulated as in Figure 1. This involves the site selection process, the definition o f a geotechnical model, a water balance model and a height-capacity-production model."

Jan 1, 1983

By W. J. Kroll

This report is concerned with the many sidelines that were investigated incidental to developing a process to produce ductile Zirconium by members of the staff of the Bureau of Mines laboratory, Albany, Oreg. The results of the main investigation, concerning the production of malleable zirconium by reduction of chloride with fused magnesium under helium, have been described in previous publications. These should be taken as a background to facilitate understanding of this work. Literature on the metallurgy of zirconium has been summarized in a separate publication (2), and references are given in this report only when new publications have to be considered or old ones stressed. Most of the observations described in this report can be applied to the problems involved in making titanium with virtually no change. In general, titanium is easier to reduce than zirconium, since its affinities are lower. Also, its chloride is easier to handle and keep clean because it is a liquid at room temperature.

Jan 1, 1952

By Richard Quirk

This report describes methods and techniques employed by The Glidden Co. of Cleveland, Ohio, in explorating an ilmenite-bearing sand deposit in Ocean County, New Jersey, during 1960 to determine ore reserve potential and the feasibility of mining and establishing a milling plant on the property for the production of ilmenite concentrate. The property covered approximately 1,250 acres. Comprehensive sampling by water-jet drilling indicated the deposit averaged 20 feet in thickness and contained 4.5 percent heavy minerals, of which 80 to 85 percent was ilmenite and leucoxene. Average depth of the water table as determined by auger boring was 16.8 feet. Pilot plant tests indicated that circular concentrators in combination with spiral concentrators would recover at least 80 percent of the heavy mineral content of the sands. It was estimated that sufficient ore reserve tonnage had been developed to supply the company's Baltimore chemicals division, pigments department, with a suitable grade ilmenite concentrate for a period of 20 years at the present rate of pigments production. The property was designated as Lakehurst mine and plans are in progress for mining development and plant construction.

Jan 1, 1963

By M. J. Raffaldi, K. W. Harris, K. A. Perry

"Highwall miners have been widely used to extract additional coal reserves from existing surface operations, particularly on contour operations in the Appalachian coalfields. Using a continuous miner cutting head, coal may be extracted from significant depths (such as 150 m), leaving behind an array of web and barrier pillars with the purpose of maintaining highwall stability. This method inherently involves elevated risks to both equipment and personnel due to proximity to and increased exposure time near highwalls. As a result, modern operations should actively design web and barrier pillars to maximize extraction while providing adequate stability. The ARMPS-HWM software, an empirical-based program created for the design of web and barrier pillars at highwall mining operations, is one such approach. The calculated stability factor is compared with empirically established guidelines produced from examining case histories.The ARMPS-HWM program is a handy tool for initial design, but understanding the site’s structurally significant geologic features and geomechanical behavior is important and may potentially increase extraction. We created a two-dimensional numerical model using FLAC3D and calibrated it to ensure pillar strength, closely following the Mark- Bieniawski formula for a typical range of pillar geometries and overburden properties. The development of pillar stresses along a highwall panel was then numerically investigated as mining progressed, and the stress distribution between barrier pillars was found to be asymmetric, which can result in an over-design of the closeout web pillars if tributary area loading is assumed. Finally, the importance of adequate barrier pillar stability is highlighted."

Jan 1, 2014

By W. D. Delahaut

Sampling tests performed at the Paradise Peak Mine compared various blasthole samplers and reverse circulation sampling methods. Statistical analysis of the data indicates that be-low-the-deck bag sampling produced a 24 to 29 percent error when compared to bulk sampling methods. Use of a chip pile wedge sampler reduced error to 17 percent. Reverse circulation sampling upgraded over bulk blasthole sampling by 7 percent for gold and 11 percent for silver. These results indicate that bias sampling conditions exist when small volume bag sampling is employed in production blasthole drilling.

Jan 1, 1991