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[Separates of all the Technical Publications published in 1928 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found either in the TRANSACTIONS or in the special volumes issued by the Institute] . METAL MINING TECHNICAL TRANS. PUBLI- TITLE AUTHOR MEETING VOLUME CATION AND PAGE* No. 50 .The Eötvös Torsion Balance D. C. Barton New York Method of Mapping Geologic Feb., 1928 Structure 52 A Cartographic Correction for the C. A. Heiland New York Eötvös Torsion Balance Feb., 1928 61. Liquid-oxygen Blasting at Chuqui- H. C. Schultz, New York camata, Chile F. K. Middleton Hunter Feb., 1928 76, 108, 123 64 Working Methods of Practical Geo- Hans Haalck New York physics Feb., 1928 65 Experiments with Eötvös Torsion P. W. George New York Balance in the Tri-State Zinc and Feb., 1928 Lead District 74 Gravity Surveying in Great Britain H. Shaw New York Feb., 1928 75 The Computation of Eötvös Gravity E. Lancaster-Jones New York Effects Feb., 1928 82 Earth-resistivity Measurements in W. 0. Hotchkiss, New York the Lake Superior Copper Country W. J. Rooney, Feb., 1928 James Fisher 83 Mining Methods and Records at the Roy W. Moore New York 76, 56, 90 United Eastern Mine Feb., 1928 98 Recent Results in Electrical Pros- Hans Lundberg New York

Jan 1, 1928

By M. R. Haibach, M. L. Shema, J. M. Silvis

"Since 2005, longwall coal mine operators in Pennsylvania (US) have been required to collect extensive hydrologic and biological data to document pre- and post-mining conditions of aquatic resources (streams and wetlands) overlying the subsidence control plan areas. Continued operation of the longwall mine is dependent upon empirical data demonstrating that the undermined aquatic resources have either been maintained or restored to an accepted range of pre-mining conditions. This study used quantitative hydrologic methods and comparative biological metrics to examine response of aquatic resources to longwall subsidence at the Bailey Mine located in Greene County, Pennsylvania. This study analyzed data from over 25 miles of streams and over 8 acres of wetlands that traverse the 4,779-acre study area. Hydrologic analysis of flow intermittency suggested that there are variable degrees of change to headwater streams immediately following mining; however, the majority of the effects are reversible through streamflow mitigation measures. Furthermore, the post-mining discharge from streams can be restored to within the range of pre-mining conditions the majority of the time. Biological assessments showed that greater than 95% of assessed stream length has maintained its ability to support benthic macroinvertebrate communities following mining and intervention (i.e., mitigation). Comparative metrics of the benthic macroinvertebrate communities showed that the biological community in 48 of the 50 sample sites is being maintained or restored across both high- and low-gradient streams. The effectiveness of intervention was further substantiated by the similarity in recovery times between streams having no intervention (median = 2.1 years, 95th percentile = 4.9 years) and streams with intervention, when recovery times were measured from the date of the intervention (median = 1.7 years, 95th percentile = 4.7 years). Changes to individual wetlands were observed between the pre- and post-mining assessments, but cumulatively a net gain of 7% in wetland acreage was realized. Hydrologic assessments were used to infer whether there was a potential that streams had been affected by mining; however, the ultimate test of stream recovery is based on biological metrics that establish the relative quality of the biological communities following mining. Overall, the hydrologic balance is being protected and the aquatic life use of streams is being maintained within the Bailey Mine’s subsidence control plan areas."

Jan 1, 2017

By Orlando Martino

This regional report covers the mineral industries of Canada and 40 countries and areas in Latin America and the Caribbean Basin. Also included is a brief description of the mineral potential of Antarctica. The Latin American region encompasses an area twice that of the United States. Latin America and Canada have a rich and diversified endowment of mineral fuels, metals, and industrial minerals. Tables 1 and 2 provide a summary view of Latin America and Canada's output of its major mineral commodities in world mineral supply in 1990 and 1991. Table 3 shows the relative importance of a selected group of minerals produced in Latin America in the world mineral economy.

Jan 1, 1993

By Ramón Alanís, Filiberto Orrante, Andrea Festa, Baldomero Gutiérrez, Fernando Cornejo

"SGS implemented two rules-based fuzzy logic expert applications on two grinding circuits operated by Peñoles Group in Mexico. Both expert systems are based on control strategies that push against process constraints to improve throughput. Based on proven methodologies, the projects also required some new approaches that led to permanent changes to the mill control strategy.This paper provides descriptions of the implementation, operation and performance of both expert systems. It also reviews how improved production rates were achieved through the use of a common set of expert technology tools. An overview of the resulting control strategies implemented on the two circuits is presented. The paper also discusses the identification of the process constraints within each circuit and how these constraints are used within the expert systems.INTRODUCTIONMexico-based mining company Peñoles Group and the Advanced Systems group at SGS, formally known as MinnovEX Technologies Inc., collaborated on the implementation of two expert systems in two grinding plants, both located in Northern Mexico.The primary objective of the expert systems was to increase throughput whilst still maintaining the cyclone overflow product size within an acceptable range. The secondary objective was to achieve a high level of utilisation of the expert technology.In order to achieve these objectives, SGS proposed a proven methodology which leveraged the existing operating and technical expertise at site through the client’s involvement in the design and implementation stages. The in-house operating and technical expertise of SGS was also brought to the project and implemented with the client’s approval at all stages. At both sites the final acceptance was defined upon meeting both process and utilization parameters.The development and deployment of rules-based fuzzy logic applications has matured as a technology and consequently, clear definition of process states and their place in the logic structure to control a given circuit are now transferable. The key to the robustness of the control logic depends on selection and tuning rules for maintaining stability and optimizing a given circuit. Application integrators need to have a standardized approach for timely integration and deployment; a critical component to avoid the common critiques that expert applications are idiosyncratic and difficult to maintain."

Jan 1, 2009

By T. Nishi, D. Teguri, K. Saitoh

In recent years the requirement for high carbon ferro-manganese (HCFeMn), which is the key product of our company, has increased due to bullish demand for steel products. In our Tokushima works, we have 2 closed types of electric furnaces (1F and 2F), with which we are manufacturing HCFeMn. In order to meet the increase in demand, we made various modifications to these furnaces and we tried to increase the furnace operating loads. Especially for 1F, we deepened the furnace. In this paper, we report the results of this modification. The operational situations of the above-mentioned two furnaces are different because they have different individual profiles. As for 1F prior to modification, the depth of the furnace was one meter shallower than2F, because 1F was designed for the manufacturing of SiMn. On the other hand, our Tokushima works specialized in HCFeMn 14 years ago. However, the profile of 1F was not optimized for HCFeMn. In comparison to 2F, 1F was more difficult to stabilize due to the smaller tolerance for the adjustment of the electrode length, the metal / slag level, and the coke-mixing ratio. We deepened 1F by 770mm by disposing of the furnace rolling mechanism. We consequently achieved a 10% increase in production capacity. This meant the operating load was enhanced from 24.5MW to 27MW, the furnace became more stable and the tapping speed of both metal and slag increased, all which made the tapping easier than before.

Jan 1, 2007

By H Chen

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in southern Perú and the northern Chile coastal IOCG belt have emerged as two of the major exploration targets in the Central Andes in the last two decades. These Mesozoic Andean IOCG deposits formed in two mineralisation epochs, the Middle-Late Jurassic (170–150 Ma) and Early Cretaceous (130–110 Ma), with the major Cu-rich IOCG deposits located in the Early Cretaceous mineralisation belt. The early studies in some IOCG centres support a magmtic-hydrothermal model for both Cu-rich IOCG deposits and broadly contemporaneous Cu-poor ‘Kiruna-type’ magnetite deposits. However, recent evidence from field, geochronology, fluid inclusions and stable isotopes show that in the major Central Andean deposits (eg Raúl-Condestable, Mina Justa in southern Perú, La Candelaria-Punta del Cobre and Mantoverde in northern Chile), the incursion of evaporite-sourced basinal brines or sea water may be a prerequisite for economic Cu mineralisation. Moreover, the Cu-poor massive magnetite deposits could be interpreted as a product from iron oxide melt, with minimal intervention by non-magmatic fluids. Therefore, they could represent two contrasted deposit types and contain little genetic relationships. The different roles of magmatism during the Mesozoic are responsible for the variable mineralisation in the Central Andes, including IOCG, magnetite and ‘manto-type’ deposits. The ore modelling for both the Middle-Late Jurassic and Early Cretaceous metallogenic epochs in the Central Andes are reconstructed.CITATION:Chen, H, 2015. The Mesozoic iron oxide-copper-gold (IOCG) mineralisation in the Central Andes – a refined IOCG ore-forming model in the Palaeozoic Continental Margin, in Proceedings PACRIM 2015 Congress, pp 251–254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By A. Karadogan, G. Tuncer, A. Kahriman

Determination of optimal blast parameters have been the priority act for blasters on the field due to financial and technical properties of the operation. Therefore many researchs were done to establish a general formula for many years. These intends could reach some empirical and numerical design frames consisting the rock, geology and explosives properties. Blasting parameters have to be adjusted according to the desired fragmentation rate especially on the mines where particle size distrubition after blasting has a great importance. Therefore the blast designs have to be evaluated considering the particle size distribution after the blasts. The Kuz-Ram model which was modified by Cunningham is one of the tools for estimating the particle size. Although it doesn’t give an accurate result, it can be very succesful on modifying the blasting design parameters by establishing a back correlation between the blasting parameters and the exact particle size distribution results which can be easily achieved by digital image processing system. Within the scope of this study, the particle size distribution after blasting was assessed by Split-Desktop digital image processing system and bench blasting parameters were studied considering the desired particle size distribution at Espey colemanite mine using Kuz-Ram and digital image processing system combination to determine the specific blasting parameters for this site.

Jan 1, 2005

The following is a Maintainability Design Checklist for coal mining equipment. The purpose of the checklist is to provide a summary of design review points for the maintainability assessment of new or existing underground equipment. It specifically focuses on the identification of equipment design features, tasks, or procedures that impact equipment downtime, repair costs, labor hours and maintainer skill level requirements. Some checklist points are general in nature. The checklist was designed to be used across all categories of underground equipment. The intent is to draw attention to design features and maintenance procedures that will increase maintainability requirements. You are encouraged to adapt this checklist to site specific or machine specific requirements by: Inserting specific performance criteria for various categories of maintenance tasks. For example; all hydraulic lines on a shuttle car should be replaceable in 15 minutes or 25 minutes, etc. Adding or deleting checklist items for different categories of equipment. You would include environmental control equipment, for example, on face equipment and not on shuttle cars or man trips. Adding additional checklist items based on site or equipment specific maintenance histories or experience, company maintenance standards, or other factors.

Jan 1, 2000

By D. Gearhart

Full-scale tests are conducted on mine roof supports using protocols developed by the National Institute for Occupational Safety and Health (NIOSH) using the unique capabilities of the Mine Roof Simulator (MRS). These protocols simulate the loading conditions that the support will be exposed to in an underground mine to determine the performance capabilities and limitations of the support. Some tests are conducted with rigid boundary conditions, creating uniform contact and near ideal axial loading conditions. These tests are used to determine the ultimate performance potential of a support, including the strength, stiffness, and stability. For prop supports where stability is a critical design issue, tests are implemented to induce buckling by a modified end condition, eccentric contact, or biaxial loading. It is important to determine the cpacity of the support design when the support is subjected to unpredictable loading conditions. This paper examines the effect of end conditions and load profiles on prop support performance and applies a new analysis methodology based on eccentric loading to determine a factor of safety for load capacity. Recommendations for installation practices that minimize eccentricity and therefore preserve capacity are also provided.

By W. C. A. van Niekerk, M. H. Fourie

The carcinogenic potential of chromium (VI) has been the subject of numerous environmental and occupational studies, from which many regulatory efforts emanated. Besides the regulation of levels of known toxic substances (e.g. Cr (VI)), the classification of dusts for regulatory purposes has thus far depended on broad definitions of particle size, mainly used to distinguish only between inhalable and respirable particles. In the past, ultrafine particles (less than 0.1 µm diameter) (PM0.1) were often regarded as a non-issue, because it was believed that significant doses would not deposit in the lungs. A growing body of scientific data is indicating that ultrafine particles are more toxic than their coarse counterparts. Increased toxicity can be related to the unique dosimetric aspects of the deposition and disposition of inhaled ultrafine particles. Secondly, ultrafine particles have a larger surface area per given mass. The increased surface area can act as a carrier for co-pollutants, specifically transition metals (including chromium) that could form a coat on the particle surfaces during particle formation. This suggests that the presence of ?inert? ultrafine particles in the environment may enhance the potential for exposure to reactive airborne compounds, including Cr (VI). These factors are particularly important when information on occupational epidemiology is interpreted. It is desirable to consider the particle size distribution, for example when occupational exposure to hexavalent chromium compounds is assessed. Since ultrafine particles are more toxic than coarse particles with the same chemical composition, it could be speculated that cancer slope factors might be related to particle size distribution. This is relevant not only to carcinogenic chromium compounds, but also basically for any particle-associated toxicants. In general, the probability of developing health effects associated with occupational toxicants is likely to be higher when these are associated with the ultrafine particle range.

Jan 1, 2004

By Lloyd Robert Nelson

The historical progression in installed electric furnace smelting capacity of some 1650 calcium, chromium, manganese, nickel and silicon ferro-alloys furnaces is reviewed. Key increases in the inherent installed electrical capacity, often achieved through uprating furnaces, are identified. Possible factors facilitating such advances are explored, including: specific process engineering and pyrometallurgical enhancements (e.g., improved control over the consistency, size and chemical form of raw materials, extents of preheating and pre-reduction delivered into the furnace; and patterns of feed distribution); furnace electrical configuration (AC or DC; immersed, submerged-, shielded- or open-arc); form of electrode (graphite, self-baking or composite); furnace configuration (circular or rectangular; closed or open and 1-, 3- or 6- electrodes); better engineering and equipment designs (e.g., high-intensity cooling) and state of furnace electrical and metallurgical control systems. A view is presented on the prevailing state of evolution of the Mega-scale in ferro-alloy smelting and opportunities for still further improvements.

Jan 1, 2014

By Stephen C. Tadolini, Gabriel S. Esterhuizen, Anthony T. Iannacchione

A Major Hazard Risk Assessment (MHRA) was developed in Australia after a series of mine disasters in the 1990’s. A MHRA is used to help prevent major hazards, i.e. fire, explosion, wind-blast, outbursts, spontaneous combustion, roof instability and chemical and hazardous substances, from injuring miners. A MHRA is a structured process that identifies the characteristics of major hazards, assesses and ranks the risk they present, and evaluates engineering and administrative controls to mitigate them. These controls typically consists of a broad spectrum of prevention, monitoring, first response, and emergency response techniques and helps to move an operation from a reactive to a proactive approach towards safety. This paper documents a MHRA performed at an underground mine where strata instabilities and fire hazards may threaten the condition of its escapeways. The objective of this MHRA is to 1) identify what hazards could affect the egress through the mine’s escapeways, 2) determine what unwanted events pose the greatest threat for the mine, and 3) recommend a plan to prevent or recover from the potential disruption of egress through the escapeway. The plan provides information on the key existing controls that should be monitored and audited, and makes recommendation of new potential controls to further reduce related risks. By documenting the use of MHRA to this specific ground control issue, this paper provides a framework for others to judge the merits of this approach and to help design and perform these activities.

By S. Sun

Recent studies on the physico-chemical properties of molten slags and oxide solid solutions of interest is reviewed. The review covers redox and phase equilibria in slags, viscosity, diffusivity, electrical conductivity, kinetics of interfacial reactions between slags and CO-CO2, interfacial properties and phenomena. Some highlights from ongoing work on modelling phase diagrams, component activity, viscosity and electrical conductivity of multi-component slags will be presented and results compared with published experimental data on slags with or without suspended solid phases.

Jan 1, 2004

By E. Lampard

Mines must manage variability from within their operations as well as those imposed upon them by external forces. This paper provides a framework to manage both internal and external variability through the review and adjustment of the mine plan where applicable to minimize lost production and maintain operational safety. KEYWORDS Mine plan, mine schedule, variability, safety, lost production, float days, update, adjustment, operations, Maintenance

May 1, 2011

By R. S. Fukuhara, M. J. Allan

"Highmont, a wholly owned subsidiary of Teck Corporation, operates a 25,000 ton/day mine and concentrator located in the Highland Valley of British Columbia. Construction of the plant commenced in the spring of 1979, and production from one grinding line began in late December 1980. The second grinding line began production in March 1980.The ore body consists of two main zones, the east and west pits, containing 134 million tons of ore, averaging 0.26% Cu and 0.27% Mo. Mineralization consists mainly of chalcopyrite (2/3), bornite (1/3), and molybdenite.The concentrator design incorporates an A-B-C grinding circuit (auto mill ball mill - crusher), followed by bulk flotation, copper-moly separation and leaching for moly concentrates. The two grinding and bulk flotation circuits are parallel and independent. Concentrate storage is provided between bulk flotation and copper¬moly separation and also ahead of molybdenite leaching. The plant design has been previously described in some detail. (""THE HIGHMONT CONCENTRATOR"" by C. V. Sibbald, CIMM Bulletin, March 1981).This paper will outline some of the problems associated with the construction, startup and early operation phases of the concentrator. The objective is to help others avoid some of the potential pitfalls by outlining those areas where problems occurred, or where things went well. Criticism of design or equipment is not intended."

Jan 1, 1982

By C. Musingwini

In the past ten to fifteen years, many organizations have applied business process re-engineering (BPR) to significantly improve their business competitiveness or stave off closures. The mining industry in Southern Africa is no exception and documented examples can be drawn from South Africa. Although the concept is superficially simple, its application has been marked by a high failure rate of about 70 per cent because it has been generally misunderstood. Shabanie mine, a chrysotile asbestos fibre producer in Zimbabwe took cognisance of this fact by cautiously embarking on a modular BPR programme in October of 2002. A year was used as a complete cycle or module for re-evaluation of the programme. Shabanie mine adopted BPR as part of management efforts to remain competitive amid serious threats to operational viability. These threats included hyper-inflation driven rising production costs, a declining world asbestos market and a possibility that Russia could take over the shrinking world asbestos market by dumping low-priced asbestos fibre. The only competitive advantage that the mine had was the high quality of its long-fibre chrysotile asbestos. The major BPR thrust was therefore to redesign processes for improved productivity and ultimately achieve a lower cost per ton of final asbestos fibre product. In addition, corporate culture change and cost-saving were also factored into the programme. This paper discusses the implementation experience of the BPR programme at the mine. The main BPR beneficial highlights are improved productivity, sizeable cost-savings, positive corporate culture change and identification of secondary projects. One of the lessons learnt from this programme is that mining companies will have to deal with the HIV/AIDS pandemic if they are to sustain high levels of productivity into the future.

Jan 1, 2005

By Vilma Beltrán

Dado que los trabajos de procesamiento metalúrgico de la mina Uchucchahua, ocasionaron impactos en el medio ambiente, afectando la calidad del agua y eliminando la vida acuática en las lagunas Añilcocha, Colquicocha y Tinquicocha, se procedió a encontrar una alternativa de tratamiento biológico que recupere la calidad de vida en la mina Uchucchacua. En este sentido, el presente trabajo describe el tratamiento pasivo de los efluentes con manganeso de la mina Uchucchacua. Para dicho procedimiento, se desarrollaron trabajos en dos etapas: el de laboratorio y balde. El primero comprende los sistemas de tratamiento pasivo anaeróbico y aeróbico.El aeróbico se inició sobre la base de los procesos de filtración y aireación a fin de determinar el grado de oxidación y precipitación del manganeso como óxido, mientras que el segundo se realizó en función a los resultados obtenidos en la etapa laboratorio y comprende los siguientes procesos: filtración, autooxidación, aireación, sedimentación. En consecuencia, los procesos anaeróbicos no favorecen la reducción de Mn II en los efluentes estudiados, mientras que los procesos aeróbicos permitieron la disminución del manganeso.

Sep 13, 2001

By R. H. Schutz

This publication lists the respiratory protective devices approved by the Bureau of Mines as of December 31, 1968, and the names and addresses of their manufacturers. The purpose of this publication is to inform the public about approved equipment for safe use in mines and mineral and allied industries.

Jan 1, 1969

By D Davies

El presente texto describe la situación del medio ambiente donde se eliminaron residuos de explotación minera, así como se revisa la legislación, el caso del desastre de Aberfan, precaución a raíz del desastre de Aberfan, seguridad, requerimiento de la junta nacional del carbón, las consecuencias financieras, la minería a cielo abierto, los problemas de las aguas, técnicas de control, las sustancias contaminadoras dentro de los afluentes de las minas de carbóny los efectos de la conservación de los ríos en el Reino Unido de la Gran Bretaña.

Jul 1, 1981

By G Akdogan, R V. R Handfield-Jones

The application of microwave energy as a substitute for conventional heating has drawn interest from many researchers in extractive metallurgy. Microwaves have a heating effect just as many other forms of radiant energy. Microwaves are able to penetrate the substance at which they are directed and in being absorbed heat the material from the inside. As a result of heat generated in the interior of a particle, microwaves can affect the rupture of a particle (in this case a host ore) and break down the matrix of the particle (host ore) and expose the recoverable mineral to the leaching reagent. Two series of leaching experiments were carried out at temperatures above 90????C using a conventional heater (hot plate) and a modified 850 W, 2.45 Ghz microwave oven. One series of tests was carried out at ambient temperature. A pyritic/arsenopyritic gold concentrate was leached with 3.3 kg/t to 6.8 kg/t NaCN for two hours. The extraction of gold at 6.8 kg/t NaCN was higher in microwave assisted leaching (59 per cent) than the extraction obtained in leaching at conventional heating (39 per cent) and ambient temperature (28 per cent). Extraction of gold was dependent on the size fraction used and was 48 per cent for û75 ¦m, 43 per cent for û90+75 ¦m and 37 per cent for û150 + 90 ¦m size ranges.

Jan 1, 2000