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By Albert E. Long

During the summer and fall of 1948 the Bureau of Mines, in cooperation with the U. S. Geological Survey, conducted 6xperiments in diamond core drilling in the Phosphoria formation in southeastern Idaho and southwestern Wyoming. Nearly all of the diamond core drilling in the Phosphoria formation has been done by mining companies interested in finding and developing phosphate-bearing beds amenable to stripping. The recovery of sludge; and enough core (usually 30 to 60 percent) to identify certain marker beds produced by current drilling practices meets both the primary requirement of mining companies in determining depth of overburden and their secondary need to determine the phosphate content of relatively thick minable units whose general composition and nature are already fairly well established.

Jan 1, 1949

By C. Özgen Karacan

Methane emissions from the active face areas and from the fractured formations overlying the mined coalbed can affect safety and productivity in longwall mines. Since ventilation alone may not be sufficient to control the methane levels on a longwall operation, gob vent boreholes (GVB), horizontal and vertical drainage boreholes, and their combinations are drilled and used as supplementary methane control measures in many mines. However, in most cases, the types of degasification wellbores chosen are decided based on previous experiences without analyzing the different factors that may affect this decision. This study describes the development of an expert classification system used as a decision tool. It was built using a multilayer perceptron (MLP) type artificial neural network (ANN) structure. The ANN was trained using different geographical locations, longwall operation parameters, and coalbed characteristics as input and was tested to classify the output into four different selections, which are actual degasification designs that US longwall mines utilize. The ANN network selected no degasification, GVB, horizontal and GVB, and horizontal, vertical and GVB options with high accuracy. The results suggest that the model can be used as a decision tool for degasification system selection using site- and mine-specific conditions. Such a model can also be used as a screening tool to decide which degasification design should be investigated in detail with more complex numerical techniques.

Jan 1, 2009

By The Staff

Introduction It is the purpose of this paper to discuss a number of the metallurgical improvements in the technology of copper-nickel ore treatment which have been introduced during recent years in the plants of ?the International Nickel Company of Canada, Limited. In common with other ore treatment processes, the procedure for extracting nickel and copper is changing almost continuous! y. These changes are necessitated by reason of changes in ore grades and characteristics, rising material and labour charges, and the constant drive to maximize metal recovery and to minimize production costs. It is not possible to present a comprehensive list of all the changes made, and only a selected number of the improvements in the milling, smelting, and refining operations are covered. It should be clearly understood that some phases of the procedures described have been pioneered by others in kindred fields and due acknowledgment is given to their foresight and efforts. Articles have been published over the years describing the operations of the International Nickel Company plants and the reader is referred to the Engineering and Mining Journal, Vol. 130, No. 9, November 10th, 1930, and to the Canadian Mining Journal, Vol. 58, No. 11, November, 1937, and Vol. 67, No. 5, May, 1946. Other references are the Transactions of this Institute, 1932, 1938, and 1946; Metals Technology, American Institute of Mining and Metallurgical Engineers, February, 1938, and Canadian Chemistry and Process Industries, April, 1940.

Jan 1, 1948

By S. Stephen Uslan

The purpose of the study was to demonstrate the effect of positive reinforcement, specifically, social reinforcement (SR), on the frequency of eye, hand, and back injuries at four experimental salt mines. Injury data was collected from January, 1976, for the prePOMOST period and from the onset of training to September, 1978, for the post-POMOST period. All data was collected on a month-by-month basis. For the training period approximately 100 managers and supervisors from five plants were trained in the use of positive reinforcement for occurrences of "safe behavior." Each supervisor was also provided manuals and other supportive materials. Additionally, following training, all supervisors were provided some coaching experience to keep the knowledge and capabilities gained during training from being extinguished. The analysis showed significant injury reductions in two sites and no injury reductions in the other two. When the injury data was corrected for the additional man hours expended in the postPOMOST period, a third site showed reduction in injuries. Similar findings were shown when the experimental sites were compared to other sites in the industry. The results were interpreted to support the hypothesis that the application of social reinforcement is related to a reduction in injuries.

Jan 1, 1978

By J. M. Hong, H. K. Zheng, R. Hu, C. B. Zhou

The Jinping-I double curvature arch dam, located in the middle reach of the Yalong River and with a maximum height of 305 m, is the world highest dam of the same type that has been completed. Since the second and third periods of the reservoir impounding, after which the reservoir water level was raised by about 200 m, a significant amount of leakage was observed out of the drainage holes deployed in the lowest drainage tunnel at the left-bank abutment at EL. 1595 m, with a pressure of 0.3 MPa at one typical hole when it was blocked. In this study, a number of analyses including water quality analysis, digital borehole imaging, tunnel geological mapping and in-situ groundwater monitoring were performed to investigate the source of leaking, the leakage passages and the performance of the grouting curtains. An inverse modeling procedure combining the orthogonal design, finite element forward modeling of the transient seepage flow, artificial neural network and genetic algorithm was invoked to further evaluate the permeability of the foundation rocks whose permeability was underestimated in design, using the in-situ measurements of flow rate and piezometric head. The geological structures that lead to the leakage were identified and the seepage flow behaviors in the dam foundation and the left bank abutment were assessed. Given the connectivity nature of the sub-vertically oriented fractures that induce the leakage event, it is found that some of the drainage holes with relative larger amount of discharge could be closed or blocked for reducing the amount of leakage without remarkably increasing the pore water pressure in the foundation rocks.

Jan 1, 2015

By Richard W. Bayley

The Atlantic City district encompasses several districts and has been previously called by different names, e.g., Atlantic gold district, Atlantic City-South Pass mining district, and Sweetwater mining district. The district is located in a terrane of folded and faulted early Precambrian metamorphic rocks which lies near the south end of the Wind River Range in Fremont County, Wyoming, Historically it is a gold district of little production, but today is an iron district of considerable importance. Gold was discovered in placer deposits about 1842 and in quartz-arsenopyrite veins about 1867, after which there occurred a mining boom lasting a few years. Minor, intermittent gold production from placers and lodes has continued to date, but the total production has probably not exceeded a few millions of dollars. Past lode mining was generally shallow ( in the oxidized zone), the deepest about 3 60 feet. The deeper, less oxidized and sulfide ores on the same lodes have not been explored. They appear to hold the only hope for future gold mining. Sedimentary iron-formation, similar to the Lake Superior taconite, occurs in the northern part of the district. Locally, where the ironformation is thickened by folds and faults, sufficient tonnages are present to be minable, as at Iron Mountain, where the U.S. Steel Corporation produces about 1.3 million tons of iron-ore pellets annually. Exploration of the iron deposits began in 1954, and the first ironore pellets were shipped to Provo, Utah in August 1962. Indicated reserves of iron-formation (about 30 per cent Fe) are reported to be about 300 million tons.

Jan 1, 1968

By D. Eugene Rannels, Yu-Chen Lee

"Lee, Yu-Chen, and D. Eugene Rannels. Alveolar macrophages modulate the epithelial cell response to coal dust in vitro. Am. J. Physicl. 270 (Lung Cell. Mol. Physiol. 14): L123-L132, 1996.-The response of the alveolar epithelium to coal dust exposure is poorly understood. Coal or other dusts may act on the epithelium directly or indirectly through nearby alveolar macrophages (AM) that produce cytokines and other soluble products. AM and type II pneumocytes (T2P) were thus exposed to dust in coculture to evaluate their possible interactions. Anthracite coal dust PSOC 867 increased synthesis of extracellular matrix (ECM) components by T2P. AM alone did not produce ECM. Similarly, coculture ofT2P with AM (3.75:1) had little effect on epithelial ECM synthesis. In contrast, coculture ofT2P with AM significantly increased PSOC 867 effects on T2P rates of ECM synthesis, ECM fibronectin content, and T2P levels of fibronectin mRNA. AM-conditioned medium did not change the PSOC 867 effect on T2P. Neither control nor PSOC 867-treated AM on Falcon culture inserts (0.45-µm pore size) over T2P stimulated ECM synthesis by either untreated or dust-exposed epithelium. Thus AM-mediated changes in ECM synthesis by PSOC 867-treated T2P require close cell-cell interactions, suggesting a role for cell-cell contact or for short-lived soluble mediators of the AM effects. DEVELOPMENT OF PNEUMOCONIOSIS, a chronic disease of coal workers that results in pulmonary fibrosis and low lung compliance, is associated with inhalation of mineral or coal dust in the work place (14). Although the pathology of pneumoconiosis has been studied extensively, cellular mechanisms that cause changes in lung structure and function are not fully understood. Particulate matter that enters the respiratory system distributes according to size, with larger particles being removed in proximal airways. Dust components of small size may enter distal alveolar region, which is populated by two types of epithelial cells, type I and - type II cells, and by alveolar macrophages (16). Each of these cell types may interact with inhaled particles, but only the effects of coal dust on alveolar macrophages have been studied extensively. Less is known regarding the response of the alveolar epithelium, or of effects on epithelial cell-alveolar macrophage interactions, in the dust-exposed lung.Function of the alveolar epithelium is well known to be influenced by the underlying basement membrane, or extracellular matrix (28). Alveolar epithelial cell extracellular matrix interactions, which may involve modulation of cell migration, attachment, or differentiation (17), are reflected in type II cell morphology, metabolism, secretory activity, hormone responsiveness, lamellar body content, and gene expression (21). The extent to which basement membrane modulates differentiation of the overlying epithelium is determined by both molecular composition and three-dimensional structure of the matrix. Type II epithelial cells in vitro synthesize, secrete, assemble, and degrade a variety of basement membrane components, including laminin, fibronectin, type IV collagen, and thrombospondin (22, 27). How expression of these components is regulated, directly or indirectly, upon exposure of the alveolar epithelium to injury by coal dust or by other particulates remains to be resolved."

Jan 1, 1998

By P Guj, J A. Bell

The valuation of early-stage exploration projects requires a valuer to take into account a large number of uncertain value drivers, the interplay among which may be non-linear. This paper examines some of the key value drivers including geology, target metrics, project area and maturity, the market and the psychology behind the decision-making process. The commonly accepted valuation methods and their underlying logic are outlined, including a view on why they evolved, what value drivers they attempt to address and their potential shortcomings. These methods include the multiple of exploration expenditure, geoscience rating, expected values and market based methods. The potential future valuation methods of replacement values and neural networks are also introduced along with how to minimise heuristic bias and error within the market-based approach.CITATION:Bell, J A and Guj, P, 2012. Exploration value drivers and methodologies, in Proceedings Project Evaluation 2012 , pp 17-28 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

The purpose of Volume II of this study is to provide a general plan for the pilot testing of two materials which could be used to tag explosives for both pre- and postdetonation identification and of tracing techniques which would thereby aid the investigator of an unauthorized bombing or explosion in being able to determine the source and/or user of the explosives. Volume I described the planning factors by which the tagging of explosives could be implemented on a National basis. 1.2 BACKGROUND Tagging explosives at the time of manufacture with a taggant material that could survive detonation, be recovered, and provide an investigative lead has been seriously studied for several years. This concept has gained widespread support among many law enforcement groups because of the scant clues that can presently be found among bombing residue.

Jan 1, 1977

By Michael J. Friedel

The permeability and flow capacity in unsaturated media are investigated by the U.S. Bureau of Mines for application to in situ copper leach mining. Moisture retention properties are derived and combined with scanning electron microprobe data to characterize the mineralogy, texture, pore size, distribution, and permeability of the host rock. Finite-element modeling is used to derive a saturated permeability, ambient degree of saturation, and assess various injection-recovery schemes. Recommended design modifications for optimization of solution distribution and maximum recovery from the rock matrix requires either (1) the injection pressures on the order of 1,500 psi and recovery wells operating in a suction mode, or (2) performing permeability enhancement, through in situ rubbling. Injection pressures can be reduced to 500 psi with improved recovery and containment of solutions.

Jan 1, 2010

By R. A. Bloomfield

This report summarizes Bureau of Mines contract research on the disposal of retorted oil shale. A data base has been developed describing the physical-chemical properties, geotechnical engineering properties, and natural cementation characteristics of spent shale. Results of field compaction tests and seepage pond tests are presented, along with results of a partially saturated finite element seepage model used to predict infiltration and seepage rates. Preliminary engineering analyses are presented for underground disposal systems, which include material transport methods, and for a surface disposal system, which includes stability analyses.

Jan 1, 1981

By J. J. Forbes

Ventilation is the most important safety factor in the production of coal because on it depends the safety, health, and efficiency of those who work underground. Without adequate and efficient means of supplying fresh air to the working faces, mining could not have advanced as it has. The extent of the workings, the increase in mechanization, and the increasing use of electricity are largely responsible for changes in methods of ventialtion. Ventilation in the early, days of coal mining was accomplished by means of a natural draft, created principally by a difference in the weights of columns of air between the intake and return openings: Later the furnace was introduced for the purpose of increasing the quantity of air in circulation. Mines continued to become larger, their output increased, men were employed in greater numbers, and more fresh coal surfaces were exposed. Coal beds near the surface, and practically free from explosive gas became exhausted, and deeper beds that liberated methane were opened as development advanced. Mechanical ventilation became necessary and was first accomplished by disc-type steam driven fans she old-.fashioned steam driven disc fan has generally been supplanted by the powerful electrically operated centrifugal fans in use at modern coal mines. In order to be secure against gas explosions and provide ample fresh air for persons employed in large coal mines, air must be conducted through the mine to all working places and to all other unsealed parts of the mince in sufficient quantities to dilute and render harmless all dangerous and noxious gases.

Jan 1, 1929

By I D. Gregson, A Gandhe, A S. Garcia, K M. MacAndrew

"Falls of ground still cause around one-third of all underground mining fatalities. The recent introduction of mechanised room and pillar working into Indian coalmines is an example of the application of new design by measurement and safety monitoring strategies, which can be used to reduce falls of ground risks in mines.Rock Mechanics Technology, now part of Golder Associates UK Ltd (Golder), is providing rock bolt support and pillar design services to the mines using a design by measurement approach. This involves in situ monitoring to confirm support and pillar designs and pillar extraction sequences.Site examples are given of the support designs determined and the monitoring programs undertaken for both design and safety.Routine safety monitoring of roof movement using telltales is also described. A new auto warning telltale has been developed specifically to warn of imminent caving as pillars are extracted.The approach used by Golder has played a major role in ensuring the success of these projects. As a consequence, mechanised room and pillar working is now firmly established in India, and wider application is planned to help meet future demand for coal.The experience confirms that the design by measurement method for this application has important advantages over conventional design approaches using analytical or empirical methods. Firstly, it measures the design performance or outcome rather than trying to calculate or predict it. Secondly, it provides the opportunity for the design to be adjusted to obtain the optimum outcome. Thirdly, it can do this at a local level, so that the support design can be matched to changing conditions to give the most cost-effective design. Finally, it incorporates long-term monitoring of support performance, again at a local level, so that subsequent change can be identified to enable corrective measures to be implemented in a timely manner and to ensure that ground control safety is maintained.CITATION:MacAndrew, K M, Garcia, A S, Gregson, I D and Gandhe, A, 2014. Application of design by measurement for support and pillar design in mechanised room and pillar coal mining in India, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

By K. Lascelles

ABSTRACT Nickel compounds vary significantly in their toxicological properties, so it is critical that continuing studies to accurately quantify worker exposures consider the processing that accompanies refining nickel-containing materials. The Clydach nickel refinery, which has operated for more than 100 years, was the first nickel-producing facility to show a high risk for lung and nasal-sinus cancers among workers employed since it opened in 1902. Process chemistry and equipment have changed dramatically over Clydach’s history. This paper describes the processing evolution at Clydach with a focus on the propensity for aerosol formation and the forms of nickel in airborne dusts.

Jan 1, 2013

By C. Ortuglio

The Bureau of Mines developed equations to determine the relationship of yields and products obtained from BM-AGA carbonization in 13-and l8-inch-diameter retorts. The developed equations indicate that results of carbonization in l8-inch-diameter retorts can be predicted from results obtained with l3-inch-diameter retorts.

Jan 1, 1966

By L P. Trout, D G. Reid

PanAust Limited (PanAust) has successfully constructed and commissioned two mining operations in Lao PDR over the past decade and undertaken major studies for three new mine developments. The management of potentially acid generating mine waste and tailings in close proximity of local communities sensitive to water discharge quality have been recurring themes that have confronted PanAust’s project study, development and operational teams. Further compounding challenges, such as the effects of intense annual tropical monsoonal conditions, staging of embankment raises and regular lifting of spillway structures, integrating mine waste and tailings management into production plans and ensuring the long term stability of structures, have been addressed by implementing leading practice management solutions.A recognition of the criticality of managing the substantial business risks associated with these crucial activities led to the early establishment of a governance structure to ensure that the highest standards are embraced for planning and execution. Importantly, these are guided and monitored by a panel of highly experienced and qualified international specialists reporting directly to PanAust’s Managing Director – the Tailings Independent Review Panel. The stewardship process has been effective in identifying potential shortcomings in management systems and has led to enhanced executive commitment to risk informed designs, assurance and overall process rigour.CITATION:Trout, L P and Reid, D G, 2018. PanAust Limited’s approach to mine waste and tailings stewardship, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 135–155 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Willem P. C. Duyvesteyn

A novel hydrometallurgical process for Escondida copper concentrates has been developed by The Minerals Laboratory of BHP. The Escondida Process consists of concentrate leaching, solution purification, electrowinning and residue flotation. Part of the copper will be sold as high grade concentrate and part as high purity SX-EW copper. Contrary to previous efforts for the development of a hydrometallurgical process for copper concentrates, this patented process does not advocate the total dissolution of copper. It only aims for the copper that is readily soluble in a mildly oxidizing environment with an ammoniacal or acidic lixiviant. Both lixiviants were studied, but ammonia was preferred because of fast kinetics at ambient temperatures and pressures. By controlling the oxidation potential, the formation of sulfate ions and, consequently, of an ammonium sulfate byproduct, is precluded. These mild leaching conditions also prevent the dissolution of unwanted impurities and result in the production of ultra-high purity electrowon copper. Solution purification is carried out by solvent extraction with LIX-54. The very high loading capacity of this organic results in a compact SX circuit, consisting of two loading, one scrubbing, and one stripping stage. As the organic is selective for simple copper ions, the copper amine complex is broken down and free ammonia is regenerated and recycled for leaching. High purity copper cathodes are produced in a conventional sulfuric acid based electrowinning system. One scrubbing step is needed to separate the ammoniacal circuit from the acid circuit. Limiting copper dissolution to less than 50% also provides an opportunity to produce high grade concentrates by residue flotation. Copper recoveries in excess of 98% with precious metal values reporting to the final concentrate can readily be obtained. Complete breakdown of the copper mineral- pyrite middlings results in a final concentrate grade that can be even higher than the original feed material. The Escondida Process also provides an opportunity to accept lower grade copper concentrates producing improved copper recoveries in the mill and yet high quality concentrates for marketing. The Paul E. Queoeau International

Jan 1, 1993

By Virgil L. Barr

National income originating compared to physical production for an enterprise or an industry reflects its ability to strengthen the national economy. For a single industrial sector or for an industry this comparison can be useful to reflect changes that may occur in this ability to contribute because of changing supply-demand-income-investment equilibria. A favorable relationship can be postulated by specified economic incentive, and the accompanying technologic input required can be shown. The new index proposes the use of the Federal Reserve Board indexes of production divided by the constant dollar income originating in the petroleum industry which reflects increases or decreases in performance. When compared with other mineral industries and with, total industry, an approximation of relative strength is evident. By constructing three different hypothetical conditions for future petroleum imports, assuming a constant excess capacity requirement for domestic production, and providing an estimate for future domestic demand for petroleum, the impact on the performance index can be shown. Thus, a strong position for the petroleum and natural gas industry can be stated. If this is done, it becomes evident that because of restrictions on cost-price relationships, a drilling program that would provide enough domestic oil to meet demand may not be practicable. By difference, the amount of improvement in methods of production and processing through technologic advancements can be stated explicitly.

Jan 1, 1960

By H M. Parker, G Verly, T Postolski

Assessing the uncertainty and risk in mineral resource estimation is required for best practice and is implied by the public reporting codes in the categorisation of mineral resources and reserves. One industry best practice is quantifying the risk on future production for a given period, which can be done using two geostatistical approaches: conditional simulation and drill hole spacing studies based on estimation variances. Conditional simulation can provide a more complete and flexible answer to the problem, but it takes a fair amount of time to complete. Drill hole spacing studies are simpler, faster and can provide reasonable assessments of mineral resource uncertainty.This paper is a presentation of the principles, theory and practice of drill hole spacing studies. Various types of risk assessment are considered. Difficulties encountered in practice are discussed, and solutions are proposed. The important parameters impacting the results are reviewed. Examples of results and sensitivities are shown.CITATION:Verly, G, Postolski, T and Parker, H M, 2014. Assessing uncertainty with drill hole spacing studies – applications to mineral resources, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 109–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By F. R. Archibald

SINCE the opening of the Beattie mine, in 1933, the concentrate produced by flotation has been considered refractory. As the gold extraction by cyanidation was poor, the concentrate, during the first four and a half years of operation, was shipped to a smelter for further treatment. After the installation of the cyanide plant, in 1934, seventy per cent of the gold in the concentrate was recovered before shipment to the smelter. In 1937, a roasting plant was built so that treatment might be complete at the mine. Much experimental work had been done by a number of investigators prior to the installation of the roasters, but none of them had seriously attempted to identify the causes of, or the elements responsible for, the refractory behaviour of the concentrate. Intensive investigation in this direction commenced in the Beattie lab-oratory in July, 1938, has led not only to the identification of several causes contributory to the refractory behaviour, but also to revisions in procedure and principles with respect to roasting Beattie concentrate in particular and arsenical concentrates in general. The accuracy of the identification of these causes and the soundness of the principles is borne out by interpretation of roasting plant records, by improvements and simplification since applied. to plant operation, and also by laboratory and test-plant results on arsenical concentrate produced by another mine. It is the purpose here to present an account and interpretation of the laboratory investigation, together with a correlation of laboratory and plant results. Incomplete extraction of the gold by cyanidation after roasting is due primarily to the nature of the material roasted, and secondarily to the manner in which it has been roasted. There is a possibility that better extraction may be obtained by improvements in both particulars.

Jan 1, 1939