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By Joseph A. Dos Santos

"The subject of this writing was first published in 1998 with the emphasis on the hardware cost comparison. Other costs, such as the required land area and spatial volume, were mentioned but not emphasized, as these were not deemed as important for new projects where the space was appropriated as required. During the last decade, these other costs have proven to be more than equal in importance. These costs are emphasized here through specific accounts of actual highangle conveyor installations that demonstrate the importance and the high-angle advantage An update on the progress in sandwich belt highangleconveyor technology is also provided.Origin and progress in sandwich belt conveyorsCover belts of the 1950s. Large volume, highangle conveying by “conveyors with cover belt, dates back to the early 1950s, when such systems were employed at the bucket wheel excavator boom conveyor in German lignite mines to increase the depth of cut without increasing the boom length. Various systems were developed, patented and built. These systems were not a lasting success for various reasons, which are noted by Rasper[1]. In his 1958 “Review of Cover Belt Systems,” Rasper summarizes the characteristics which are worth pursing and those that should be abandoned. The former are akin to good conveyor engineering. The sandwich belt conveyor model. The first sandwich belt conveyor model allowed calculation of the required hugging pressure to develop the bulk material’s internal friction and preclude material slideback. A modern, accurate version of the sandwich belt conveyor model is presented in Fig. 1. This model depicts accurately a derating of the material cross-section allowing an ample belt edge distance that can tolerate normal belt misalignment without material spillage. The calculations must thus recognize that only part of the hugging pressure is imparted onto the material with the remainder transferred belt edge to belt edge affecting a material seal. Mathematical development of the sandwich belt model is covered by Dos Santos and Frizzell in their 1983 article, “Evolution of Sandwich Belt High Angle Conveyors.”"

Sep 1, 2016

By R. B. Crookston

This paper presents the status and mining method chosen by each of the active underground oil shale projects in the united States today. Potential improvements in equipment and methods on the near-term horizon are discussed. The problems and potentials that lie in the long-term future of oil shale mining are examined in light of the demands which must be met by this developing technology.

Jan 1, 1981

By J. O?Shea

From the characteristics of the new (1976) electronic components and units that are being marketed, the author has tried to foresee the types and the performances of the near-future slope-monitoring equipment. Much-improved sensors, instruments and systems for pit use can now be developed - sun-powered telemetry remote stations are feasible, very sensitive as well as precise and drift-free liquid level inclinometers will be available, new techniques for distance measurement with lasers obviate the need for atmospheric corrections and the latest generation of desktop calculators have become easily programmed minicomputers. Thus, it is realistic to assume that fully automatic pit-slope monitoring systems will be operational in the foreseeable future.

Jan 1, 1978

By William Petruk

The mineralogy of the primary and oxidized ores from the Malanjkhand porphyry copper deposit in India was studied to determine ore characteristics that affect metallurgy, and to assess applicable processes for recovering the copper. Three mineral assemblages were found. One occurs in primary ore, another in moderately oxidized ore, and a thir:d in intensely oxidized ore. Chalcopyrite, the main mineral in the primary ore, is relatively coarse-grained, with grain size increasing as the ore grade increases. High chalcopyrite liberations should be achieved at a relatively coarse grind, and good chalcopyrite recoveries should be obtained. The chalcopyrite, however, tarnishes readily and oXidizes to chalcocite in a relatively short time (several months). The presence of both the tarnished chalcopyrite and chalcocite may affect chalcopyrite flotation and reduce copper recoveries, The moderately oxidized ore occurs in an oxidized cap immediately above the primary ore, and stockpiled primary ore alters quickly to a moderately oxidized ore. Chalcocite is a major copper-bearing mineral in moderately OXidized ore. The concentrator processing this ore should be capable of handling a chalcocite-rich ore. The intensely OXidized ore contains a wide variety of acid-soluble copper-bearing minerals. Leaching may be required to recover the copper from them.

Jan 1, 1987

By C Hedemann, N Silveste, H Davis, C J. Moran

For nearly two decades water scientists have been debating the need to use appropriate models for the questions being asked and the data available. This paper puts forward a rationale for a hierarchical framework for water balance modelling as it applies to mine sites. The hierarchy is based on the complexity of models and their data requirements. Scientific models are the most complex and require the most data; next is engineering models, then systems models and the simplest representations are given by conceptual models. A position is put forward that systems models have a range of uses that the others do not provide. A systems model, called SiteMiser, is described and its calibration illustrated. The model is applied to seven coal mines from the Northern Bowen Basin in Central Queensland. Currently, there is little relationship between total water use and coal production. This relationship is not any stronger when fresh (raw) water is compared to reused water. Leading practice water use levels are simulated for all sites. The simulation results demonstrate that there is considerable opportunity to reduce water consumption and, in particular, to import less fresh (raw) water to the sites.

Jan 1, 2006

By Donald E. Redmon

This Bureau of Mines report examines the injury experience in the quarrying industry for the years 1964-65. Twenty-eight tables for each year are presented in which disabling work injuries are summarized by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By Mehmet Guney

[The Atlantis-II-Deep is a hydrothermal mineralization located along the median valley of the Red Sea at a water depth of about 2200 m. Extensive exploration of the metal-rich brine deep revealed a potentially mineable deposit on economic interest consisting of oxides, silicates and sulphides with considerable concentrations of zinc, copper, cadmium and silver. Geostatistics was applied to assess the most likely in-situ vague of the metal potential for economical exploitation. Semi-variograms were constructed to characterize the structure of the regionalized distribution of the geological parameters. Volume grades and thicknesses were determined by the kriging technique, avoiding systematically biased high or low grades, and then block .tonnages were computed. The estimation variances, distribution of errors and histograms of observed and kriged values in each grid Mock were also produced.]

Jan 1, 1983

This manual provides basic practical instruction on the inspection of driven piles. It covers the essential components of pile driving, such as the pile driving hammer, hammer accessories, the pile and soil, and frequently encountered test methods in an uncomplicated, yet knowledgeable, and practical manner. Insight is given into the methods of installing the foundation, dealing with the cranes which do the lifting, the hammers which do the driving, the leads that guide the hammer and pile, the compressors which provide the external power when required, and finally prevalent analysis tools and testing instrumentation and procedures which enable you, the Inspector, to do your job. This DFI Inspector's Manual for Pile Foundations will help the Pile Inspector who has limited knowledge of pile foundations. Perhaps this Inspector has been pressed into service at a moments notice; a few helpful hints and suggestions to him are desperately needed and he can look here for the basics. It is also useful for the experienced Pile Inspector as a reference guide. However, this manual is not a detailed check list of every possible scenario and detail which could ever be encountered. There are other sources available which give more detailed descriptions (and should be consulted by the Inspector when appropriate; a list of this additional reference material is provided and suggestions made in appropriate chapters of this text). The current manual is more a brief "textbook overview" with some of the more important aspects given at least some emphasis so that the Inspector has some direction and hopefully helps to produce a safe, yet economical, foundation.

Jan 1, 1997

By John F. Papp

The objective of this U.S. Bureau of Mines study is to calculate an accurate, reliable estimate of chromium and nickel content of stainless and heat-resisting steel produced in the United States. The columbium, manganese, molybdenum, titanium, tungsten, and vanadium contents of this steel are also calculated. Such contents are required for estimating the quantity of alloying element recovered from recycled stainless steel and consumed by market sectors. In this investigation, the elemental fraction of stainless and heat-resisting steel was calculated as the ratio of the weight of element contained in stainless steel to the weight of stainless steel produced. The elemental fraction has been calculated as a time-averaged, grade-averaged value. The elemental fraction was averaged from 1962 through 1983, and averaged over the grades for which production was reported by the American Iron and Steel Institute during that time period. The 1962-83 average elemental fraction of U.S.-produced stainless and heat-resisting steel was calculated for chromium to be about 0.17 ± 0.01; columbium, 0.00014 ± 0.00003; manganese, 0.015 ± 0.005; molybdenum, 0.004 ± 0.001; nickel, 0.07 ± 0.01; silicon, 0.009 ± 0.001; titanium, 0.0004 ± 0.0001; tungsten, 0.0001±0.00003; and vanadium, 0.00003±0.0000l.

Jan 1, 1991

By Xiaodong Yu, Jinxia Zhang, Fusheng Niu, Hongmei Zhang

The three-dimensional (3D) fractal dimension is an important parameter to analyze the 3D structure and flocculation effect of the hematite flocs. In this work, the 3D fractal dimension of hematite flocs was predicted by establishing the particle swarm optimization (PSO) algorithm optimized with the back propagation (BP) neural network (PSO-BP). The proposed model considers four factors, namely, the flocculant quantity, flocculation time, stirring speed, and temperature, as the input parameters. We normalize the input data during the preprocessing stage. The BP neural network was optimized by using the PSO algorithm for realizing the 3D fractal dimension. The prediction accuracy and effectiveness of the model were evaluated. The experimental results showed that the predictions performed by the proposed PSO-BP neural network were better than that of BP neural network. In addition, the root mean square error (RMSE), mean squared relative error (MSRE), mean absolute error (MAE), and mean absolute relative error (MARE) of the proposed model are lower, compared with the errors of the BP network. Similarly, the measurement coefficient R2 of the proposed model is higher, compared with the BP network. The maximum absolute error of the model is 0.0772, the maximum relative error is 0.02405, and the regression coefficient r is 0.98592. These results showed that the proposed model has a good performance and high prediction accuracy. When verifying the practicability and the effectiveness of the proposed PSO-BP model, the prediction results of 10 groups of hematite flocculation experimental data under different conditions showed that the prediction value of the proposed PSO-BP model was closer to the ground truth as compared to the BP model. Therefore, the proposed model is suitable for predicting the 3D fractal dimension of hematite flocculation.

Oct 3, 2022

By Randy McMeekin, Chris Twigge-Molecey, J. Peter Blake

The business objectives of a metallurgical project determine targets and constraints, such as the range of products, production capacities, in-service dates, and capital and operating cost parameters. Permitting is usually left to the project team, as are decisions regarding site location, technology, and construction approach. Success requires an orderly methodology, represented in this book by front end loading (FEL) phases: FEL1 examines several alternative approaches; FEL2 ranks and eliminates less economically or technically attractive options; and FEL3 develops the preferred option to the point of major permit completion, with defined scope, schedule, and cost to submit for approval to proceed with implementation in FEL4. Working through FEL1, FEL2, and FEL3, the project definition improves, estimates become more accurate, and project risks are reduced. The project design basis at the end of FEL3 is the control document for project implementation in FEL4.

Jan 1, 2015

By Malte J. M Gurgel

Subsurface spatial planning is becoming increasingly important in view of competing underground applications. This development is influenced by global agreements to reduce greenhouse gas emissions. Therefore, precise knowledge of the underground space is a basic prerequisite for future applications. The three-dimensional registration and reliable georeferencing of underground infrastructures can establish a holistic geodata basis for such tasks. Those tasks are discussed both for the development of energy projects such as deep geothermal energy as well as for storage applications. Research on geothermal energy has been carried out at RWTH Aachen University as part of the SuperC project in a license field in the Aachen area since 2001. Recently, this research has been extended to include monitoring aspects in the overlapping GEObservatorium Aachen field. The documentation and visualization of underground activities using photogrammetric methods like Structure from Motion is discussed based on recent research in sites for the final disposal of radioactive waste. Finally, both applications provide an outlook on supporting underground projects by using high-resolution geodata.

Feb 1, 2025

By Luis de Montreul

El presente texto describe la mineralogía del oro que comprende sus asociaciones con otros minerales metálicos, relaciones con las gangas no metálica, granolometría, abundancia y las características textuales de los minerales. Para ello, es vital conocer la selección del método de tratamiento a emplear para obtener una óptima recuperación del oro.

May 1, 1986

By Rodolfo Lagos, Nicos Pfeiffer, Ben Harding, Clayton V. Deutsch

This paper documents a probabilistic resource modeling workflow for the Round Mountain epithermal gold deposit. The set of categorical and continuous variable simulated realizations provides a model of variability and uncertainty given the current orebody knowledge. These realizations can be used to quantify and understand expected deviations in reconciliation during mining and provide a more accurate measure of expected gold than an estimated model. Gold mineralization at Round Mountain is primarily contained within tertiary tuff units, which dip gently to the west and thicken towards the southern part of the orebody. Domain boundaries are modeled as combinations of lithology and alteration; alteration domains are constrained to be within the tuffs. Large-scale geologic uncertainty is strongly influenced by parameter uncertainty, particularly the input histogram. The spatial bootstrap characterizes prior global uncertainty in the input histogram for categorical and continuous variables. Categorical models are generated using hierarchical truncated pluri-Gaussian (HTPG) simulation. Continuous variable simulation is carried out within the simulated domain boundaries using trend models to account for non-stationarity.

Aug 19, 2023

By W. L. Uglow

In recent years, the microscope has come to be recognized as a valuable aid to engineers whose business is the discovery, development, concentration or reduction of metallic ores. In many of the large treatment plants microscopical research has already an important status; and in the hands of efficient operators the microscope has indicated methods of solving ore problems resulting in the saving of thousands of dollars that otherwise might have been lost in tailings, or expended in freight rates or smelter charges. Failure to procure all the information that the microscope can supply concerning the physical and mineralogical characteristics of complex ores has in many cases led to the construction of unsuitable concentrators, just as the failure to investigate in detail the geological conditions of an ore deposit has often results in the squandering of money on shaft sinking, and mechanical installations which subsequent development of the deposit failed to justify. The great progress recently made in the selective separation of minerals by means of the various processes of flotation and leaching brings strongly to our attention, the scope of the field in which microscopical methods may be advantageously employed. The microscope enables one to observe the minute details of rock, ore, gangue, concentrate, tailing, matte, slag and metal, that are invisible to the naked eye. Furthermore, the technique of microscopal research has been so highly developed that a microscopist can not only observe, but deter-mine the compositions and measure the diameters of the mineral constituents in the ore to be treated. Magnifications of these constituents up to 3,000 diameters may be produced by the proper combination of eyepiece, objective, and projection apparatus, and the images thus viewed may be photographed through the microscope, and permanent records made of them.

Jan 1, 1924

In October, the Aluminum Company of America restarted the fourth of seven pot-lines at its Point Comfort, Tex. primary aluminum smelter. The price of primary aluminum ingot, as quoted by American Metal Market, was increased from a range of 60.5 to 63.0 cents per pound at the end of September to a range of 66.0 to 66.5 cents per pound at the end of October. BERYLLIUM On October 15, Brush Wellman, Inc., of Cleveland, one of two U.S. producers of primary beryllium products, announced a planned $6 million expansion of its extraction plant at Delta, Utah, increasing the plant?s capacity to extract beryllium from bertrandite ore by 25%. Another $5 million will be spent on two mine expansion programs in Jaub and Millard Counties, Utah. Other mineral claims and 1 eases he 1 d by The Anaconda Company will be taken over by Brush Wellman through lease or purchase. This expansion, when completed in 1981, will decrease U.S. dependence on imported beryl ore.

Jan 1, 1979

By V. V. Clark

WHEN a district is more or less primitive, and a trained mining engineer attempts single- handed to prospect it according to old standards, he generally fails. He has not the ability to live out in the open alone for months at a time and carry on with enthusiasm and determination like the old-time prospector. But the same engineer, placed in an organized group where modern prospecting methods are employed, is immediately put on his mettle and his chances of winning are greatly increased. Marsman Investments, Ltd., with headquarters in Manila, has at the present time, Sept. 4, 1937, six prospecting parties in the Netherland East Indies. Three of these groups are combing their assignments for lode mines, studying structures, developing and reaching out into veins and zones with diamond drills. The other three are searching for placer mines with pans, pits, and Empire drills. I am in charge of one group seeking commercial gold placers on the Island of

Jan 1, 1937

By W B. Edgar, S C. Dominy

High-nugget effect vein-gold systems are generally considered to be one of the most challenging of deposit types to evaluate and exploit. To potential investors and mining companies, they are viewed as high risk because of the associated uncertainties in the grade estimate and general paucity of Ore Reserves at production start-up. However, despite the well-known risks, these deposits often have a grade upside that makes them potentially attractive. The reporting of resource grade is of importance and perhaps even more so is the reporting of the associated uncertainty attached to the grade estimate. The use of the grade estimate supported by a grade range is recommended to achieve more complete and useful disclosure. The definition of the grade range can be somewhat subjective, ranging from opinion based estimates through to data-based estimates and geostatistical conditional simulation. Whichever method used, the over-riding issue must be the provision of enough data of appropriate quality and full disclosure to the public of relevant uncertainties.CITATION:Dominy, S C and Edgar, W B, 2012. Approaches to reporting grade uncertainty in high-nugget gold vein projects, in Proceedings Project Evaluation 2012 , pp 95-108 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By M. D. Marshall

A remote heat-activated stench gas/tracer gas mine alarm system was developed to reduce the time between fire detection and personnel notification. The stench gas/ tracer gas system contains ethyl mercaptan for personnel warning and a fluorocarbon for tracer gas detection by instrumentation. A system was also developed which can be interfaced with multiplex mine phones. In-mine tests were conducted and several systems are presently installed in a hard rock mine.

Jan 1, 1983

By Ewan Wingate, Ranjit Prasad, Yanjun Liu

The use of phosphorus by mankind is long established. From use in agriculture, foods, high tech electronics, and more recently in EV battery cathode production, one cannot escape its impact on today’s society. This paper will review and describe the circular journey of phosphorus through its value chain from the mining operation of phosphate ore through beneficiation into downstream chemicals production and finally into the EV battery cathode production space. This will include a review of phosphoric acid production from phosphate concentrate using wet process route and thermal route. The wet process route discussed will be via dissolution of phosphate concentrate by sulphuric acid. The thermal route will discuss thermal decomposition of phosphate concentrate using submerged arc furnace to produce yellow phosphorus followed by its combustion to produce phosphorus pentoxide and subsequent hydration to produce phosphoric acid. It will also discuss briefly other phosphate derivatives for specialty chemicals and recovery of phosphorus units from wastewater treatment plants, sewage sludge and incinerator ash. Finally, the paper will discuss the use of phosphorus in EV batteries in the form LFP cathode materials and its production. It will also briefly discuss the LFP battery recycle.

Sep 11, 2023