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By Alan D. Brown

"Diesel-electric trucks are those that have some portion of the convention-al mechanical drive train replaced by electrical components. As larger and more powerful diesel engines appeared, the development of mechanical transmissions and related drive components failed to keep pace, and electrical generators and drive motors therefore came into use as an efficient means of transferring the mechanical energy of the engine to the driving wheels of the vehicle.The Berkeley Pit has been a major testing ground for the evolution of this type of truck. We now operate a haulage fleet consisting of conventional diesel trucks and two different types of diesel-electric trucks. There-fore, we have been able to obtain an interesting comparison of costs and performances between these three types of haulage units.In all phases of operation, the diesel-electric truck commands a favourable advantage over the conventional diesel truck, and represents a more efficient and less costly means of haulage. Nearly all manufacturers of heavy-duty trucks are now building, or have plans to build, such a truck."

Jan 1, 1966

By E. J. Burrough

Coal Reserves The Crowsnest Pass coal fields form part of a greater area which comprises the Inner Foothills belt of the Alberta coal fields and the southeastern coal fields of British Columbia. The most valuable and most extensive reserves of the bituminous coals of Canada are concentrated in this?area, of which the Crowsnest Pass fields form an important part. The extent of these coal reserves together with those of the rest of Canada were recently studied by the Geological Survey of Canada for the Royal Commission on Coal of 1946 (1). Quotin from the report, it is of interest to note that, prior to this work, the most widely known, and in fact the only Canadian-wide estimates of, coal reserves of Canada available to the Commission were those prepared by Dr. Dowling in 1913 (2). At that time it was estimated that Canada's reserves of coal were over twelve hundred billion tons. The more recent estimates of mineable coal for the whole of Canada are of the order of 10 per cent of that figure and are reported. as 99 billion tons, which is further reduced to 40 billion tons on the basis of the estimation of recoverable coal. This considerable divergence in estimated reserves is explained in part by the big difference in the bases of measurements. For example, in the original report, seams of one foot occurring at a depth of 4,000 feet were included in the estimates.

Jan 1, 1951

By Thomas E. Weyand

Prior to 1975, lead-based paints were commonly used in protecting steel structures. Because of the toxic effects of lead on human health and the environment, their use has been significantly reduced. However, problems with these paints persist when they are removed during normal maintenance by pneumatic blasting with mineral abrasives. Technologies are developed to contain the spent abrasive and paint during blasting operations. This paper reports on A study to identify beneficial reuses for the spent blasting material. Nine samples were gathered from different projects within Pennsylvania. The samples were thoroughly characterized with regard to composition, morphology, and EP and TCLP leach test performance. Potential reuse applications will be reviewed with regard to technical adequacy, economics, and environmental constraints.

Jan 1, 1992

By M Scoble, W S. Dunbar

This paper reviews methods for grade estimation in short-term mine planning for block caving. Two particular tools are used: Ordinary Kriging and Simple Kriging with moving averages. It is also considered the influence of draw characteristics on the grade estimation process. Reference is made to mine case study data and analysis. These demonstrate that operational grade estimation is not a trivial process. It must take into consideration: the grade variability (in terms of ore and dilution), sampling interval, geological and geotechnical characteristics, geometrical layout and draw characteristics. Significant improvements appear possible in short-term planning if variogram analysis, as well as kriging methodologies, are introduced into the operational grade estimation process.

Jan 1, 2000

By C. Pritchard

John Marks said in his acceptance of the Hartman Award in 2008, "I guess that without the occasional complaint, your mine is probably over-ventilated" (Marks, 2008). Miners are seldom in this situation and spend much of the time trying to find enough air to keep an operation running. With examination, there are usually changes that can be made to increase the efficiency of ventilation systems. Mine ventilation air is a costly commodity, especially by the time it has been heated or cooled and moved to the bottom of the shaft and through the mine airways. Modifications that result in surplus mine ventilation air could bring financial and environmental benefits. Some issues mine operators have needed to address recently are increased airflow requirements to dilute diesel particulates in metal and nonmetal mines, to ventilate reserves that are deeper, hotter, and further away from fans and shafts, and to meet demands from increased production. This paper discusses successful methods to find additional usable air when there is no extra ventilation capacity. Most of the options presented in this paper are useful for metal/ nonmetal operations but some may be applicable to coal as well.

Jan 1, 2010

What has happened to the basic coal industry during the past year? Has it been a better year for coal than 1961? What striking new developments have occurred in mining, preparation and utilization? Are there positive signs that production will go up? What has happened in the utility market, the metallurgical market and the export market? Is the controversial question of coal transportation nearer to a solution? What progress has research made for coal during the year? The answer to these and many other important questions are offered in the following review of the Coal Industry-1962.

Jan 2, 1963

By M. B. Greyver

The results of laboratory tests on iron precipitation from non-decopperized nickel anolyte are discussed. The parameters (pH, oxygen consumption and stirring speed) for iron precipitation from the anolyte, using the oxygen in the air, were determined. In the experiments conducted under optimized conditions, the residual concentration of iron in the anolyte after precipitation was 0.7-2.7 mg/L, and the copper and nickel losses to the solid phase were 0.05-0.07% and 0.05-0.16%, respectively. The filtration ability of the iron slurry obtained was 2 to 5 times higher as compared to that after chlorine oxidation and oxyhydrolysis. The leaching of the non-ferrous metals from the iron cake made using the separate nickel anolyte purification process was possible by dissolution in sulphuric acid. It was established that after cobalt precipitation from the copper- and iron-depleted anolyte, the precipitates obtained had lower ratios of Fe:Co and Ni:Co.

Jan 1, 2006

High pressure grinding mills have been successfully introduced in the industry. They offer the possibilities for capacity increase of existing plants and reduction of operating costs. Further metallurgical advantages in gold and copper are possible. The plants in operation are running in different applications and modes of operation. They can be installed in a combination with SAG and ball mills or in a stand-alone mode. In combination with other grinding mills, it has to be investigated how the HPGR can be installed to reach the full efficiency. This paper describes the possibilities to implement high pressure grinding rolls and shows by case studies the potential of savings which could be reached

Jan 1, 1996

By T. G. Joseph, M. J. Bolster

ABSTRACT This paper explores passive seismic measurement as an alternative, nonintrusive approach to conducting annual brake testing on surface mine sites. Dictated by the test site location, this evaluation adhered to the brake testing procedure as per British Columbia occupational health and safety regulations. Results showed excellent correlation to those reported via conventional practice: Comparing stopping distance, time, and velocity for the proposed instantaneous passive seismic versus conventional approaches, less than a 0.5% variance was evident. A viable alternative, the passive seismic approach, allowed an entire fleet of trucks to be sequentially evaluated for annual brake testing without disrupting operations by installing mechanical testing equipment.

Jan 1, 2012

By Kristine L. Pankow, Keith D. Koper, Michael K. McCarter, Jared R. Stein

"The Wasatch Plateau region of central Utah contains a number of active underground coal mines in an area of well-documented natural seismicity. As a result, there are several hundred seismic events recorded in this region every year that may or may not be attributed directly to mining activity. Previous studies have linked the majority of this seismicity to mining activity through various means, but have not attempted to develop a method for categorizing individual events within a seismicity catalog. This study uses both relative relocation and waveform cross-correlation to separate events based on hypocentral depth and waveform similarity, respectively, in the area surrounding a single longwall coal mine within the Wasatch Plateau. We conclude that relative relocation can help with depth discrimination, but there are some unavoidable limitations caused by sparse seismic network coverage. The cross-correlation technique is more promising, with the ability to group events by waveform similarity and track mining progress over both space and time. With cross-correlation based clustering, we confirm that the vast majority (97.6%) of events in the study area are directly related to mining activity, but that a small population of natural seismicity is present as well. Eliminating this natural seismicity from the catalog of seismic events, leaving only those events related to mining, can give operators valuable information about the changing conditions as mining progresses and eliminate concern over events unrelated to mining activity.INTRODUCTIONA number of underground coal mines are located in the Wasatch Plateau region of central Utah, and have been in operation since the late 1800s. This activity has resulted in a well-known history of mining induced seismicity (MIS) (Wong, 1985). Additionally, this area is situated near the border of the Basin and Range and Colorado Plateau physiographic provinces, where naturally occurring tectonic earthquakes also occur (Arabasz et al, 1980). Seismicity separating these physiographic provinces is part of a larger band of seismic activity known as the Intermountain Seismic Belt (ISB) that runs from Montana to Arizona and cuts through the western boundary of the central Utah coalfields (Smith and Arabasz, 1991) (Figure 1)."

Jan 1, 2015

By H S. Welideniya, K Ekanayake

Carbon rich graphite deposits found in Sri Lanka are of inorganic origin and they occur as narrow steeply dipping veins. The vein width of these deposits varies from a few centimetres to metres, with an average vein thickness of 1 m. It is believed that the carbon rich fluid intruded into fracture zones under high pressure and the temperature has crystallised into graphite. This process has also generated many minuscule graphite veins centred on main mineralisation, which has reduced the host rock overall rock mass rating. These discontinuities could also be considered as joints with graphite infill. Graphite mining at Bogala Mines, Sri Lanka is a unique example of narrow vein mining faced with numerous wall stability issues resulting from weak graphite infilled joints.The Bogala vein type graphite orebody has an average vein width of 1 m. Overhand cut-and-fill mining method is used for stoping. The stope consists of two boundary winzes for material handling, access and ventilation. Mining is done on the strike of the vein and the average mining slice height is 2 m. A void to the height of one mined slice is left below the mining level during mining. Waste rock resulting from vein blasting and mine development is dropped into this void as fill rock. Any void height left greater than a single slice height will increase stresses in the stoping zone. This will increase formation of rock blocks and their effective separation from wall rocks. Split miniscule veins occurring around main mineralisation intensifies rock block formation in an environment of mining induced stress release. Consequently, any rock blocks sliding into stopes on graphite infilled joints will behave under constant normal stiffness (CNS) conditions and their shear strength will converge rapidly towards remoulded shear strength of graphite alone. Unlike with general infill deposited in joints, graphite has a very low friction angle and with its slippery nature, a small thickness may affect in great deal to reduce joint shear strength.In addition to immediate filling of excavated voids, controlled vein blasting and spot bolting have improved mine safety. Furthermore, rock bolts connected to each other through iron plates and anchored to anchor bolts installed in non-fractured solid rock are practiced to stabilise rock falls and wedge failures in narrow vein graphite mining. These practices have significantly contributed to safe mining without any rock bursts and catastrophic failures.CITATION:Welideniya, H S and Ekanayake, K, 2012. Challenges faced by narrow vein graphite mining and influence of graphite infill on wall stability, in Proceedings Narrow Vein Mining 2012 , pp 71-76 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By O. A. Velasquez, A. R. Kumar

"Dust generated on underground mechanized coal mining faces is a health and safety hazard. Continuous miners deployed underground usually have an integrated flooded-bed dust scrubber mounted onto the machine that arrests the generated dust from close to the face and cleanses the air around it. However, the impingement screen might get clogged depending on the coal seam being worked. This necessitates the cleaning of the screen which in turn, reduces the overall availability of the scrubber and, hence the continuous miner. A novel non-clogging screen has been developed at the Department of Mining Engineering, University of Kentucky. The proposed impingement screen is built up of three individual aluminum screen units 1.5 mm thick and separated by 3 and 2 mm respectively. The screens have long vertical slits measuring 6 mm. A water spray continuously keeps the screen wet and provides for the filter element to arrest the dust particles. The slits force the dust-laden air to make sharp turns. The dust particles cannot change directions rapidly, impact one of the three screens and are separated out based on their momentum. Preliminary computational fluid dynamics (CFD) models have indicated significant cleaning efficiencies in the respirable range at the expense of much lower pressure drops. Results indicated by CFD models and supported by laboratory experiments have been discussed in this paper.ACKNOWLEDGEMENT The authors acknowledge the National Institute for Occupational Safety and Health (NIOSH) for funding this research. Dr. Thomas Novak, Professor of Mining Engineering, is also acknowledged for his continued support and encouragement. INTRODUCTION Continuous miners are ubiquitous in coal mining around the world. The miners are operated against bling headings, ensuring adequate flow of air at the face could be difficult. The minimum requirement of ventilation airflow quantities at those coal faces are legislated to dilute dust generated to harmless levels. New dust rules promulgated recently have further called for lower exposure levels of personnel working underground (Courtney) (MSHA, 2014) (NIOSH, 2010). Water sprays are also installed at strategic locations and serve as powerful air-movers. The sprays capture some amount of dust generated while cutting. In addition to this, usually, all continuous miners are equipped with a flooded-bed dust scrubber as shown in Figure 1 to capture the dust from close to the extraction drum (Chao & De-sheng, 2000) (Wala, Vytla, Huang, & Taylor, 2008) (Organiscak & Beck, 2010)."

Jan 1, 2018

By Sravya Kosaraju, Christian Ekberg, Stefan Allard

Li-ion batteries are now used in electric vehicles (EVs), plug-in hybrid vehicles (PHEVs) and, hybrid electric vehicles (HEVs). Nanostructured Li(NiyMnzCo1-y-z)O2 is one of the more popular cathode chemistries for automotive Li-ion battery, due to its enhanced properties such as large surface area, short diffusion length, enhanced ionic and electronic conductivity, improved mechanical strength and structural integrity [Pan et al, 2013]. Recycling of Li-ion batteries helps to mitigate environmental effects of virgin metal extractions along with improper disposal of end of life batteries. To fulfill these objectives of the recycling, recovery of pure streams of the involved metals should be considered. In this study, the batteries were first discharged and dismantled in an inert atmosphere (Ar). The electrodes were then heat treated in a box furnace. This was done in order to break the chains of the adhesive (PVDF) and consequently separate the metallic substrates Cu and Al from the electrochemically active compound. This heat-treatment also helped to simplify the dissolution of the metal constituents in the electrochemically active compound from the cathode in the acid leaching process. Solvent extraction was chosen to achieve separation and recovery of metals with higher purity from these leachates. In the scope of the present work, a complete process from the point of dismantling to separation of constituent metals using solvent extraction was studied.

Jan 1, 2014

By C. Cristonffanini, S. Nazari

"In the past, simulation was considered to be an offline tool disconnected from plant operation. Advancements in the computation power combined with utilizing physics and chemistry sciences have allowed us to significantly improve the modeling and simulation technology for mining and mineral processing. This paper investigates the benefits of first principle models and simulation by connecting them to real time operation. Process data are connected to high fidelity models executed in parallel to the operation. In recent literature, this concept is known as Digital Twins. The Digital Twin is used for various purposes such as optimization, virtual instrumentation and condition monitoring. Using IDEAS™ simulation software we are able to construct a digital twin for different equipment inside a mineral processing plant. Two case studies for building a digital twin for the primary hydrocyclone feed pump and thickener underflow are presented. Using the pump’s model, a digital twin is developed and is installed in a gold extraction plant that is able to infer the slurry density in real time. Additionally, it is used for detecting sanding in the pipes and impeller condition monitoring.INTRODUCTION Since the eighties, thanks to advances in computation technologies, computer based simulation of processes using first principle models has become a well-known engineering tool for various industries. As our understanding of processes has increased, their representative models have become more realistic and more sophisticated. Due to this increase of accuracy, use of simulation is becoming more fundamental in process industries. The main goals to use accurate simulation is to decrease the engineering and construction cost, optimize the process design and improve the operation performance by decreasing operation cost and increasing efficiency. The term Digital Twin was first introduced in 2010 by NASA (Shafto et al., 2012) in aerospace industry. Subsequently, the concept quickly spread through other industries. As of today, no standard organization has provided an official and unique definition of Digital Twin for process industries. However, there are three important aspects that are common throughout various descriptions. When simulation is core functionality of the process (1) along the entire life cycle of the plant (2) with direct linkage to operation (3), it is called that process has a Digital Twin. According to Gartner, the concept of Digital Twin has elected as fourth most important disruptive technology for the year 2018 (https://www.gartner.com/, 2017)."

Jan 1, 2019

By Stephen H. Stow

The relationships between the amount of light reflected off 21 samples of Florida phosphate and the chemical, composition of the samples were examined. It was found that the reflectivity of a rock is directly related to its chemical composition and that darker phosphates (less light reflectance) have relatively high amounts of iron, organic C and sulfate while lighter-colored rocks were rich in phosphorus, fluorine and aluminum. The use of reflectivity measurements could have economic applications in the phosphate rock industry: color specifications for rock shipments could he met, beneficiations by optical sorting could be performed and semi-quantitative analyses could be made rapidly and inexpensively.

Jan 1, 1971

By J. O'Leary, R. Cannell, D. Honsberger

"The Scully Mine deposit lies within the group of metasediments that together comprise the rocks of the Labrador Trough. The ore itself still retains the bedding characteristics of the parent rocks and on this basis has been divided into three main members, namely: Upper, Middle and Lower. The Upper and Lower both show many of the bedding characteristics of the cherty taconites of the northern U.S.A.; the Middle member is a coarse-grained friable specularite rock. The ore minerals are hematite (normally present in the specular variety) and magnetite, although the latter rarely occurs in concentrations greater than 20 per cent. Gangue minerals are quartz and the hydrated iron oxides. Manganese oxides also occur as accessory minerals. The outcrop area of the orebody is in excess of 2 square miles, displaying a complex pattern of faulting and folding, which has been formed as a result of at least two orogenic periods."

Jan 1, 1972

By William D. Riley

The U. S. Bureau of Mines has developed technology to recover by-product materials from aluminum scrap using engineered scavenger compounds (ESC). ESCs are structural oxides with a channel or tunnel structure that allows them to hold ions of a specitksizes and charges. The scavenging reaction is easily reversible allowing the ESC to be recharged for continued use and the ion is recovered as an electro deposit. Key features of this novel technology are; a) ESC ,systems are designed to have a high degree of selectivity for a desired ionic species. b) The recovered mater.ial requires little or no additional reprocessing prior to reuse. Two current uses for the ESC technology that are described in this paper are the removal and recycle oflithium (Li) from lithium aluminum (Li-AL) alloys; and, using ESCs as a replacement for the conventional demaging (magnesium removal) technology used by the secondary casting industry. Research indicates that the ESC technology proposed for both these applications has either 'distinct economic and/or environmental advantages over previously employed methods of recovering. metal values from aluminum scrap.

Jan 1, 1995

By C. E. Jordan

The Tuscaloosa Metallurgy Research Center of the Bureau of Mines, U.S. Department of the Interior, is investigating the recovery of phosphate from beneficiation slime, as part of the Bureau's efforts to conserve mineral resources through increased use of wastes. Phosphate equivalent to about two-fifths of U.S. production is discarded annually in the wastes. Exploratory flotation tests on the plus 5-um fraction of a slime sample showed promise for a classification-flotation technique. Onsite classification tests at six phosphate washing plants were conducted with a two-stage hydro cyclone system designed to recover the plus 5-um material. The cyclone underflows contained 8.3 to 19.1 percent P2O5, and the recovery of the plus 5-um PZOS values ranged from 81 to 95 percent. The percent P2O5 recovery from the total slimes ranged from 38 to 47 percent. Batch-flotation studies are currently being conducted.

Jan 1, 1978

By Robert R. Beebe

On the night of August 1'9-20, 1995, seepage was seen at the toe of the Omai tailings dam in Guyana. The mill was immediately shut down, and within two hours the flow, then mostly water, was diverted into an inactive mining pit nearby. At about the same time a second more serious break occurred at a point where water and solids could flow directly into the Omai River. By the time Ii coffer dam could be completed in the early morning of August 24, some 4.2 million cubic meters of tailings water and solids had escaped from the dam, of which nearly2.9 million cubic meters had reached the Omai River. This paper outlines some initial Process considerations and operational decisions which might have contributed to the dam's failure, describes how the Government of Guyana and the operator, Omai Gold Mines Limited, cooperated in dealing with immediate problems and shows how the Government set about investigating the accident. In particular, the paper details the work of a Process Review Committee comprising Guyanese and foreign experts convened to assess the gold processing and effluent management systems at Omai, and to recommend actions where appropriate.

Jan 1, 1998

By J. B. Evans

"NORMALLY the duties of the exploration engineer and geologist cover the initial, and possibly, the most important phase of mining property evaluation; that phase being the presentation of an opinion of the property's ore reserve potential in terms of tonnage and grade. The prime objective of this pa-per is to outline one method of bridging the wide gap that lies between a know ledge of a property' s tonnage and grade potential and an appreciation of the value of that property in dollars and cents.THE PRESENTATION OF PROPERTY EVALUATIONThe engineer engaged on a mining property evaluation, regardless of whether he be an independent consultant, or a company employee, has as his goal, the presentation of his appreciation of the property's potential value or worth within terms of reference acceptable to his principal.To furnish a complete evaluation report, the evaluator must firstly study all aspects pertaining to the particular property under consideration, then present his appreciation of the property's worth in some tangible form. The ultimate presentation is one giving a Present Value of the pro pert y in terms of monetary exchange. Such an idealistic presentation is not always possible; typical preventives being -insufficient reliable information, limited time, Jack of ability and absence of definite direction."

Jan 1, 1960