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By K. Esmaieli

This paper addresses issues associated with ore pass degradation caused by material impact. A series of numerical experiments, using the particle flow code, were undertaken to investigate the influence of various finger raise configuration. This has allowed the identification of favorable configurations. The results of this analysis, when coupled with field observations, can contribute to the design of ore pass systems that can prolong the useful operating life of ore pass systems.

May 1, 2009

By Sean Masse

New Gold?s New Afton Mine, located 8 km (5 miles) west of Kamloops, British Columbia, is a 4.5-Mt/a (5-million stpy) block cave mine, making it the highest tonnage underground hard rock mine in Canada. The reserve is estimated at 52.5 Mt (55.9 million st) with grades of 0.65 g/t (0.02 oz/st) gold and 0.93 percent copper (2012). Commercial production was achieved in July 2012 and nameplate production was achieved ahead of schedule in September 2012, with the cave breaching to surface in 2013. The mill has a SAG and a ball mill with a froth flotation circuit.

Jan 1, 2014

By S. G. Dixit

Alunite (KAl3(SO4)2(OH)6] is one of the important nonbauxitic resources for aluminum in U.S.A. The major gangue material associated with a unite ore body is quartz. Experimental results indicate that oleic acid flotation of alunite is quite effective in upgrading the ore. The flotation chemistry of the alunite/oleate system has been investigated using various techniques such as: hallimond tube flotation response, measurement of adsorption density using I4C labeled oleated, electrokinetic measurements, infrared spectral studies, contact angle measurements and thermochemical measurements using an isothermal microcalorimeter. Alunite has been found to float readily with oleate in the pH range 4-10.5 and its flotation response is enhanced at higher temperatures. The PZC of alunite has been determined to be at pH 7.2 ± 0.15 which agrees with what would be predicted from solution chemistry and from the flotation response with physically adsorbed collectors. Infrared spectra show a specific peak in the range 1585-1600 cm-1 which has been attributed to the formation of an aluminum oleate surface species. Both adsorption density measurements and infrared spectra indicate that during adsorption multilayers are formed. The heat of adsorption of oleate on alunite has been found to be endothermic and of the order of 4-6 KJ/ mole.

Jan 1, 1980

By Henrik Saxén, Mikko Helle, Hamid Ghanbari

In this study, a process integration approach in a primary steelmaking is investigated to evaluate future operation concepts of a steelmaking site considering sustainability issues. Mathematical programming is used to study the integration of the steel plant with chemical units for utilization of available off-gases in the system, and carbon capturing and sequestration unit. Different industrial carbon utilization options are considered to find the best route of development. A multi-period optimization model is developed based on site-wide mass and energy balances by considering the availability of the fuels and by-product gases and their consumption in the production system and a conceptual polygeneration system. The objective is to reach maximum economic profit while environmental aspects of integrated system are considered for different fuel systems, alternative blast furnace reductants and implementation of new process technologies. The model can provide useful information concerning techno-environmental and economic aspects for decision-making and can estimate optimal operational condition of current and future primary steelmaking under alternative scenarios. The results of the work illustrate the potential to develop steelmaking towards more sustainable operation in the future.

Jan 1, 2015

By A. L. Valdivieso

"The correlation obtained by plotting pH of maximum adsorption of dextrin versus the isoelectric point of involved metal hydroxides can be used to predict the depressing effect of dextrin on flotation in ""pure"" sulfide mineral systems. Sulfides are strongly depressed by dextrin whenever their surfaces are coated by the corresponding metal hydroxide. The efficiency of dextrin as a depressant is affected by the adsorption of the sulfhydryl collector. Hydrolyzable cations modify this relationship in flotation of sulfide ores. This type of deviation of the real-life systems from the predictions based on the behavior of the pure systems shows the possible ways that could be followed to further improve the obtained correlations. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists ofCIM Sudbury, Ontario, Canada Edited by"

Jan 1, 2009

By Alexander Burns

Electrolytic salt splitting is a technology where acid and/or base is regenerated from a neutral salt using membrane electrolysis. Recent advances in the understanding of brine treatment, membrane stability, and cell design have made electrolytic salt splitting feasible on certain hydrometallurgical solutions. Meanwhile, environmental regulations have made the bulk disposal of salt solutions more difficult. In this paper, sodium sulfate salt splitting is examined from a cost perspective, compared to purchasing the reagents directly. Relative costs are estimated for several regions based on published electricity and reagent prices. The results show that salt splitting is economically favourable in some regions, and can be made more favourable by applying modifications to the traditional three-compartment desig

By M. Z. Naghadehi, E. Emami, J. Sattarvand, R. Battulwar

In this paper, a methodology for a computerised recognition of joint sets on 3D point cloud models of rock masses is presented. The process starts with classifying joints on a 3D rock mass surface through training a deep network architecture and validated using manually labeled datasets. Then, individual joint surfaces are identified using the Density-Based Scan with Noise (DBSCAN) clustering algorithm. Subsequently, the orientations of the identified joint surfaces are computed by fitting least-square planes using the Random Sample Consensus (RANSAC). Finally, the joint planes are classified into different joint sets, and the dip direction and dip angle for each set are calculated. The performance of the proposed methodology has been evaluated using a case study. The results show that the presented procedure is fast, accurate, and robust.

Sep 1, 2021

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By G. Clarkson, M. Hitch, R. Clarkson

"A novel reagent-free method of extracting gold from gravity middling concentrates in the Yukon placer fields is presented in this paper. This method exploits the malleability of gold by submitting concentrates to grinding in a rod mill. Brittle waste minerals are effectively reduced, whereas malleable gold particles are flattened and are then extracted by classification through sieves. Recoveries in the field using a laboratory-sized rod mill regularly exceeded 90%, whereas correlation laboratory tests indicated recovery to be most sensitive to the mill charge size. This method has broad potential, including application to the gravity circuits of large hard-rock processing circuits.RÉSUMÉ Cet article présente une nouvelle méthode sans agents réactifs d’extraction de l’or dans les concentrés gravimétriques mixtes que l’on trouve dans les districts placériens du Yukon. Cette méthode exploite la malléabilité de l’or en broyant des concentrés dans un broyeur à barres. Les déchets miniers cassants sont bien réduits, alors que les particules d’or malléables sont écrasées puis extraites par classification au travers de cribles. Si les récupérations sur le site à l’aide d’un broyeur à barres de laboratoire excèdent 90 %, les essais de concordance en laboratoire indiquent que la récupération est très sensible à la taille de la charge du broyeur. Cette méthode présente un grand potentiel, notamment une application possible aux circuits gravimétriques des grands circuits de traitement des roches dures.INTRODUCTIONExploiting the high density of gold to separate it from waste materials is the oldest known mineral processing technique. This basic technique is still widely used in gravity concentration circuits today; however, gravity processing invariably results in high-value middlings, especially in the Yukon placer gold fields. In addition to having a uniquely high density, gold is also the most malleable metal. This unique malleability can be exploited to extract gold from otherwise inaccessible gravity middlings.The Yukon placer gold industry has been continuously ongoing since the 1860s, and today produces approximately 60,000 oz t (1.87 million grams) of crude gold annually, most of which is from the Klondike region near Dawson City (Van Loon & Bond, 2014). It is important to note that Yukon placer miners do not use any chemical extraction methods; rather, gravity upgrading methods are the sole processing techniques used. Placer deposits are typically coarse, well liberated, and naturally gravity concentrated and recoverable, thus making more expensive chemical extraction unnecessary (Mitchell, Evans, & Styles, 1997). Furthermore, a strict permitting regime, environmental concerns, lack of expertise, and fear of repercussions from regulators prevent miners from attempting more advanced processing methods, such as flotation or cyanidation. Even simple chemical extractions like mercury amalgamation have not been implemented for decades, with one observer noting that, as many as 30 years ago, “the art of mercury for amalgamating appear[ed] to be dying [in the Yukon]” (Osler, 1983)."

Jan 1, 2017

By R. D. Wilson

Ten to twelve million tons of dust is produced by cement kilns annu-ally in the United States, resulting in a serious waste disposal problem. The Bureau of Mines investigated two alkali volatilization methods for converting this dust into materials for making portland cement and a useful potassium product. Portland cement kiln dust was found to be composed of finely ground cement raw materials (CaC03 and 8i02) having a layer of alkali sulfate (K2S04 and Na2S04). In this form, it cannot be directly recycled to cement kilns because concrete is weakened by a reaction between the alkali and the aggregate. Portland cements with 28-day strengths above 5,000 psi were produced from low-alkali residues using sintering and melting methods. For nearly complete removal of alkalies, primarily potassium sulfate, from cement kiln dust, a temperature above 1,300° C and a reducing atmosphere were required.

Jan 1, 1986

By D. A. Paice

A power supply to operate fluorescent or mercury vapor lamps from 300 volt dc coal mine trolley wires has been developed for the Bureau of Mines. A high frequency regulated inverter unit incorporates ballasts for a mix of lamp loads up to 650 watts. For 600 volt trolley systems an additional power converter unit was developed to step down the dc voltage to 300 volts for the inverter unit. Both units have operated in a working coal mine for over 12 months without need for servicing. The lamp load in these tests included two 100 watt mercury vapor head lamps and six 75 watt fluorescent lamps.

Jan 1, 1979

By Yousef Ghorbani, Jafar Abdolahi Sharif, Fatemeh Kazemi, Ataallah Bahrami

Kinetic models are the most important tool for predicting and evaluating the performance of flotation circuits. Gilsonite is a natural fossil resource similar to an oil asphalt, high in asphaltenes. Here, in order to determine the kinetic order and flotation rate of a gilsonite sample, flotation experiments were carried out in both rougher and cleaner stages. Experiments were conducted using the combinations of oil–MIBC and gas oil–pine oil, with one test without collector and frother. Five kinetic models were applied to the data obtained from the flotation tests using MATLAB software. Statistical analysis showed that the results of the experiment with oil–MIBC were highly in compliance with all models. Kinetic constants (k) were calculated as 0.1548 (s−1 ) and 0.0450 (s−1 ) for rougher and cleaner stages, respectively. Rougher and cleaner tests without collector and frother also matched all models well (R2 > 0.98), with k values of 0.2163 (s−1 ) and 0.284 (s−1 ), respectively. The relationship between flotation rate constant, maximum combustible recovery, and particle size showed that the maximum flotation combustible recovery and flotation rate were obtained in the size range of −250 + 106 μm in the rougher and cleaner stages. The combustible recovery and flotation rate were higher in the rougher flotation process than in the cleaner stage.

After more than 20 years dependence on bituminous coal as a primary fuel for generating electricity, the Pennsylvania Power and Light Company initiated a one-year study on the economics of building an electric generating station using anthracite as a fuel. The study will be completed in December 1976. If the feasibility study so indicates, PP&L will consider installing four 400,000 kilowatt generating units for scheduled commercial operation in 1985. Each unit would consume up to one million tons of anthracite annually. Anthracite generally is more difficult and expensive to extract than bituminous coal, but it has a significantly lower sulfur content than the bituminous coal currently being used by PP&L, thereby eliminating the costs of installing sulfur emission controls at generating stations. Moreover, significant reductions in transportation costs may be realized because the utility's operating territory is situated in the center of the anthracite region in northeastern Pennsylvania. These advantages may indicate that the use of anthracite is more economical than bituminous coal to PP&L. ASBESTOS -Asbestos production in the U.S. dropped again in 1975 until it was just two-thirds of that in 1973. This was in spite of the very strong demand caused by the Quebec strike. The 7-month strike of the asbestos miners in Thetford Mines, Quebec cut off 55 percent of the normal supply of U.S. consumers. Apparent domestic consumption was less than 75 percent of that in 1974. The wage settlement will probably result in a 20 percent increase in asbestos prices.

Jan 1, 1975

By Connell JE

The Worthing Mine near Hallett Cove. 20 km southwest of the cite of Adelaide, belongs to Aus- tralia's first mining era, which took place in South Australia between 1841 and 1851 (Figure 1). Oper- ations began in 1849 only six years after the com- mencement of metal mining in Australia at Glen Osmond. Although not as historically significant as Glen Osmond (1841), or the much larger copper mines of Kapunda (1844) or Burra (1845) its importance lies with its Cornish enginehouse and chimney. The Worthing enginehouse, built in 1851-1852 is the oldest remaining in Australia and certainly the most significant relic of Australia's first mining era. Six other stone enginehouses were built during that period: at Kapunda in 1848 and 1850: at Burra in 1849, 1850 and 1851; and at Tungkillo in 1849. All of these houses have long since dis- appeared although the foundations of one (Kapunda, 1850) still remain. The significance of the Worthing site is enhanced by its magnificant environmental setting in the bare, steep valley of Field River. Currently (1986) the Worthing Mine is the only site within the City of Marion which is on the Register of State Heritage Items. The site is also included in the Classified List of the National Trust of South Australia and on the Register of the National Estate.

Jan 1, 1987

By J. C. Nigro

The potential use of prereduced pellets in the burden of the blast furnace continues to be a topic of interest. Several excellent papers have been written describing the theoretical and experimental rewards. (1) (2) (3) (4) (5) (6) (7) (8) (9) Significant increases in iron output and substantial savings in coke consumption are major advantages over conventional iron oxide pellets. The savings are especially important in areas where good coking coal is at a premium. Lower handling and transportation costs may also be factors favoring prereduction. When considering the overall cost of making and smelting prereduced materials the optimum metallization level becomes significant. An analysis by Agarwal and Pratt of the thermodynamic aspects of blast furnace operation with all prereduced pellets shows that the criteria controlling coke consumption depends upon the degree of reduction and upon the percentage of oxygen (present as FeO) removed by solution loss.(8) The authors state that although the chances of obtaining large fuel savings are greatly improved when metallization is high, reduction to the highest degree, which is costly, may not result in the lowest energy requirement per ton of hot metal; thus, over reduction could possibly result in wasted energy in the blast furnace.

Jan 1, 1968

By Steven R. Ahlfield, Ali Ghandeharioon

A wastewater treatment plant commissioned in 1978 is undergoing a major expansion. Planning various phases of the 8-hectare expansion at this site requires an understanding of the site response during and after construction, and the potential impact on adjacent properties and infrastructure. The expansion project requires nominally 5 m of site grading fill for flood protection. The site is underlain by loose to compact fine sand over firm to very stiff clay stratum that extends to great depths. Ground improvement is required to mitigate the liquefaction hazard in the fine sand stratum, and preloading is proposed to reduce post- construction settlements in the deep clay. Site development and foundation systems for the plant expansion project were evaluated by conducting settlement analyses which accounted for the historic and future site loading and 3-D modeling of soil layers with interpolation between borehole and cone penetration test (CPT) locations. The numerical model was calibrated to match short-term and long-term settlements measured at the plant site. The analyses were carried out to assess the effects of past loading, proposed preload and surcharge heights, lateral extents and durations as well as vibro-replacement ground improvement on post-construction settlements. Two design options were considered for the preload footprint across the site and foundation system for proposed facilities. It is shown that limiting the preload extent and founding some of the proposed structures on deep friction piles reduce the predicted settlements of adjacent infrastructure and result in reasonable performance for the proposed facilities. INTRODUCTION A wastewater treatment plant commissioned in 1978 will be replaced with a new plant on an undeveloped portion of the site to provide wastewater treatment for an expanded service area. The existing facilities must remain in operation until completion of the new plant. The site grade will be raised nominally 5 m for flood protection. The large areal extent of the site grading fill and plant structures will cause stress changes extending to great depths in the underlying soils and result in settlement of the existing and new structures. Historic settlement of the existing facilities has been tolerable for plant operations, but no settlement performance data was recorded during site development and post-construction from 1978 to 2007. Development of the 8-hectare expansion at this site is planned in three phases to reduce the overall construction schedule. Planning for each phase requires evaluating the effects of various site development activities from start to completion of expansion and during the design life (i.e. post-construction period), and the potential impact on existing wastewater treatment facilities and adjacent properties and infrastructure including an adjacent viaduct structure. Figure 1 presents the site plan and three distinct site development phases considered for the plant expansion.

Jan 1, 2019

By H-S Yang, H Park, S-J Kim, Y-H Ko, H-S Kim, S-H Cho, J-K Kim

An investigation was undertaken to devise a new method for reducing dust spread during blasting demolition utilising water tube and detonating cord. Modelling of smooth particle hydrodynamics (SPH) with AUTODYN software was initially completed to determine the expected diffusing behaviour of the water tube. The actual behaviour was then captured with high speed videos during each experiment, and each result analysed in detail. Water mist diffusion was generated and analysed by changing three key variables. In sequence, these included changing the location of detonating cord in the tube, the charge quantity and the tube diameter.As a result of experiments and simulation, optimum design for ideal diffusion behaviour was suggested and each behaviour of water mist was classified by diffusing shape of water tube as the design criteria.CITATION:Ko, Y-H, Kim, J-K, Kim, S-J, Park, H, Kim, H-S, Cho, S-H and Yang, H-S, 2015. Mist diffusion experiment and evaluation of water tube for blasting demolition dust control, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 809–814 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By W. A. Gow, G. M. Ritcey, M. C. Campbell

"Uranium is a unique commodity. It is both a metal and a fuel, It has both commercial and military uses. It yields ""clean energy "" but presents environmental concerns. All of these factors have an impact on the commerce of uranium.Being a metal, uranium is extracted from ore like many other metallic minerals. As a fuel, it is subject to the vagaries of energy commodity market forces. The history of uranium in the first nuclear weapons has led to nation al governments carefully controlling production and sale of uranium. The spectre of radioactive contamination of the environment adds further to the public concern over the disposal of low-level radioactive wastes from uranium processing and use.There have been a number of excellent reviews on the commercial aspects of the uranium industry. In this discussion, these aspects will be briefly summarized to provide a general picture of the strengths of the Canadian uranium industry and the pressures to which it is being subjected currently. The principal thrust of this paper will be to outline Canada's resource strength and to identify some factors which will affect Canada's ability to continue holding a sizeable share of the world uranium market."

Jan 1, 1985

By G. Zhu

Bulk and differential laboratory flotation tests have been carried out using a synthetic mixture of chalcopyrite and molybdenum ore. In addition to boiling and roasting, six different depressants are tested so that the best conditions of separation can be identified. These reagents include sodium cyanide with and without zinc sulfate, potassium ferrocyanide, sodium hydrosulfide, arsenic Noke's reagent, and sodium sulfide. The data indicate that most of these reagents are effective chalcopyrite depressants. However, sodium hydrosul fide can be used preferably if economic, operational, and environmental factors are taken into consideration.

Jan 1, 1983

By A. D. McMahon

Changes in world mine and smelter supply sources of zinc have led to changes in zinc supply patterns in the United States during the past 3 years, 1970-72. The result has been a growing reliance on foreign sources of zinc metal to furnish an ever-increasing portion of expending domestic requirements. This review of fundamentals and historical developments is intended to provide background in order to place the future of the U.S. zinc industry fn perspective. The properties and uses of zinc are described. A new study on U.S. reserves is presented with description by geographical region and comparisons with older reserve data. The technology of the zinc industry from prospecting through refining is described with emphasis on the metallurgy involved in the various methods of smelting. Production, consumption, and imports are discussed and illustrated with graphs and tables to review the past and present patterns. Government actions affecting the industry are shown.

Jan 1, 1974