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Jan 1, 1991

By Bruce Clements

The Bagdad mill, located near Bagdad, AZ, was built in 1977 with a designed mill capacity of 36.3 kt/d (40,000 stpd). An autogenous mill-ball mill crusher (ABC) grinding circuit was chosen. The original mill contained three independent grinding circuits. Each contained one 9.75m-diam x 4-m-long (32-ft-diam x 13-ft-long) fixed-speed autogenous mill, a4.7-m-diam x 6.7-m- long (15.5ft-diam x 22-ft-long) ball mill and one 2. 1-m-diam (7-ft-diam) short head cone crusher. Total installed power per grinding circuit was about 8.4 MW (11,350 hp), with 5.9 MW (8000 hp) in the autogenous mill, 2.2 MW (3000 hp) in the ball mill and 261 kW (350 hp) in the crusher (Fig. 1). The autogenous mills were designed to be able to operate semi-autogenously. However, they were never converted to semiautogenous grinding (SAG) mills. As a result of this design, only about 4.1 MW (5450 hp) of the designed power is used in the autogenous mills. The grinding circuits are closed, with 2.4 x 6 m (8 x 20 ft) double-deck vibrating screens. A series of conveyors re- turn screen oversize underneath the mill coarse ore stockpile to feed the crushers. Variable speed belts feed the crushers and control power draw. Crusher product reports directly to the tail end of the autogenous mill feed belt (Fig. 2). A magnetic sensor detects tramp iron in the autogenous mill-crusher circuit.

Jan 1, 1992

By C. Cunningham

The process of initiating opencast blasts through long cables is onerous. An obvious alternative is to replace these with radio controlled firing apparatus. Such devices appear from time to time and with the advance of telecommunications, more are likely to appear. However, there are two crucial and seemingly intractable obstacles to overcome: firstly, the problem of malfunction of the system, which can either fire prematurely or go into a state of suspense in which it is unknown whether firing might unexpectedly occur, and secondly, the problem of terrorism, as such a system could provide the capability for an off the shelf remote bomb. The issues of accessibility and electronic reliability when linked to explosives in a mining environment have to be demonstrated to be adequately covered before serious consideration should be given to these systems, up to now largely confined to military applications.

Jan 1, 2003

By J, T C. McCuaig, J Hodgkison, T Fouet

Olympic Dam is the eighth largest Cu deposit and the largest U deposit in the world, with approximately 35 million tonnes of contained Cu and 1.2 million tonnes of U. The most recent resource estimate was for 2.95 billion tonnes of mineralised material with average grades of 1.2 per cent Cu, 0.4 kg/t U, 0.5 g/t Au, 2.6 g/t Ag as contained mineral resources. Olympic Dam is expected to produce >200 000 tonnes of Cu and 4200 tonnes of U3O8 from 9.8 million tonnes of ore in 2004, making it the 12th largest Cu producer in the world. One of the impediments to achieving targeted rates of production has been oversize material (>0.9 m) reporting to stope draw points. A major contributor to oversize material may be overbreak along pre-existing structural weaknesses from stope walls and backs during the production life of a stope. Underbreaking to structures can also have a detrimental effect on the performance of a stope. In an effort to understand the influence of structural geology on stope performance, WMC Resources and SRK Consulting partnered during 2003 to refine the current system of structural mapping, and to use historical data to produce a structural interpretation covering a large part of the mining area. The interpretation has been wireframed in DATAMINETM into a three-dimensional structural framework model. To date, there are more than 600 structures of >50 m strike length incorporated into the structural framework model, which covers a study area 1500 m + 600 m + 350 m. A back-analysis exercise to assess the influence of interpreted structures on overbreak and underbreak was completed for laser-surveyed stopes.

Jan 1, 2004

By José Gutiérrez, Cosme Soto, Octavio Vargas

El presente trabajo detalla las etapas más relevantes del proceso de cambio de la Guía Industrial 7 (IG-7) a la regulación S-K1300 cuya finalidad es reportar Recursos Minerales en la Bolsa de Nueva York. Los autores desean brindar una guía sobre las situaciones y retos más importantes sucedidos durante el proceso de adaptación y auditoria para reportar recursos minerales bajo regulación S-K 1300 en la Cia. de Minas Buenaventura. También, plantear una metodología para ponderar tanto las variables que le dan soporte a la estimación de las leyes, como los ítems que brindan calidad a la información de Geología.

May 10, 2023

By K Broadley

Risk and dispute resolution are linked. Dispute resolution techniques are brought to bear on a dispute - which is an outcome of a risk being wholly or partially realised. There has been an increasing awareness by business of risk as a component of doing business. There is an accompanying awareness of the need to manage risk - including legal risk. Many companies have undertaken a systematic review of their potential risks and endeavoured to put in place systems to help to avoid or manage risks. A legal risk management program will not prevent disputes arising. However, such a program should prescribe how that dispute will be managed. The management of the dispute will involve consideration of the dispute resolution procedure to be adopted. The most appropriate processes will take into account the practical, personal and commercial considerations surrounding the dispute and be as efficient, cost-effective and user friendly as achievable in the circumstances for the benefit of all the parties. Carrying on business in South East Asia, whether as an explorer or a mining operator, brings additional considerations to bear in legal risk management and the dispute resolution process. A significantly different perspective is required due to the varying nature of the legal systems in many South East Asian jurisdictions. These jurisdictions often have relative uncertainty as to the law. This impacts on the dispute resolution processes and also raises further timing and cost issues. The authors contend that this is all the more reason to endeavour, as practically as possible, to adopt a legal risk management and dispute resolution profile which will provide business with the greatest prospects of maintaining control of the dispute resolution process. This presents a greater chance of a successful outcome to the dispute. In these times of increasing pressures on profitability because of low mineral prices, all costs of a minerals business are being reviewed. In such times, a significant legal dispute may have even greater potential to adversely impact on the companies concerned, together with the careers of the people involved. In this paper possible approaches to managing disputes and a case study a legal dispute in which Freehill Hollingdale and Page were involved are discussed. The dispute concerned an international mining company developing a gold mine in Indonesia and one of its contractors in Indonesia. Described is how that dispute was resolved. This achieved a very satisfactory result for the client - all things considered. Given the æadditionalÆ problems associated with ascertainment and enforcement of ærightsÆ in South East Asia, the longer the parties can retain control over their dispute the better off they will be. For this reason, the authors set out in this paper the main additional dispute resolution tools available - that are appropriate for use throughout South East Asia.

Jan 1, 1999

By Ken Norris

"Campbell Mine which has been in continuous operation since 1949 has undergone numerous operational changes in the past 3 years. This paper describes the process changes which have occurred at the Campbell Mill since 1991. The paper discusses the engineering, construction and startup of the effluent treatment circuit, the new oxide filtering and merrill-crowe precipitation circuit, and the changes to the pressure oxidation circuit. Particular attention is paid to startup problems and solutions to these problems. A review of the benefits and results of these process changes is also discussed. Future changes are also briefly reviewed with anticipated goals and expectations.IntroductionCampbell Mine is a gold mine 100% owned and operated by Placer Dome Canada. It is located in Balmertown, Ontario which is located 300 kilometres northeast of Winnipeg, Manitoba. The Campbell Mine has been in continuous operation since 1949, producing nearly 8,000,000 ounces. In 1993 Campbell Mine is budgeted to produce 289, 750 ounces of gold at a cash cost of $157 US/ounce. Daily mill tonnage is budgeted for 1,430 tons/day but has milled as high as 1,600 tons/day on a consistent basis. Recovery in 1993 is 93.4% and is budgeted to average 94.5% in 1994.In the 1992 edition of the proceedings of the Canadian Mineral Processors conference I described the changes that were made at Campbell starting in 1989. This paper continues where the 1992 paper ended and discusses the changes to the Campbell mill since that lime. The changes to Campbell since January 1992 have been numerous with capital expenditure in the mill exceeding $14.1 million. This paper describes three primary projects since that lime: the effluent treatment project ($5.5 million), the oxide leach/filtering and merrill-crowe project ($4.6 million) and the pretreatment project ($2.81 million). The focus of this paper is to highlight the justification of each project, the design and engineering, and some of the initial operational problems and solutions applied to those problems."

Jan 1, 1994

By Jimmy Gabriel, Hugo Aráoz

El agua es un componente ambiental que prácticamente afecta todos los procesos de las operaciones minero – metalúrgicas en la UNIDAD MINERA Orcopampa, en este sentido la gestión de recursos hídricos busca justificar todos los posibles usos del agua en las operaciones, el que también incluye las medidas de control o mitigación que permitan reducir los riesgos de manera preventiva y proactiva. En este sentido las actividades implícitas a la gestión de recursos hídricos van desde la evaluación de las fuentes de agua disponibles a fin de cumplir con la demanda de agua para las operaciones mineras a corto y largo plazo.

Sep 1, 2017

By D. Tao, R. Honakey, B. K. Parekh

The dewatering of stable phosphatic clay suspensions generated from phosphate beneficiation in the central Florida is an issue of practical and theoretical importance. Because of its tiny particle size and surface charge, the phosphatic clay takes up to 20-30 years to settle in water and causes environmental, aesthetic, economic, and handling problems. An efficient and cost-effective dewatering/consolidation process for phosphatic clay is of great interest to the phosphate industry in Florida. In this paper, the consolidation and dewatering behavior of phosphatic clay was studied by use of anionic flocculants with and without sand addition. The effects of pH, initial polymer concentration, polymer dosage, polymer addition steps, and metal cations (K+, Ca2+, and Al3+) on the flocculation of phosphatic clay have been studied. Experimental results indicated that clay suspensions were well flocculated at pH 10.5 by DPW-1-1355 and Magnafloc 5250 flocculants acquired from Ciba Specialty Chemicals. Sand particles from phosphate flotation added to the clay slurry promoted flocculation and increased clay consolidation. K+ showed good performance to improve the flocculation characteristics by neutralizing clay surface charge. The adsorption mechanisms of flocculants on clay particles were also discussed in this paper.

Jan 1, 2006

This volume constitutes the final report for the Rescue Subsystem portion of the Coal Mine Rescue and Survival System program conducted by the Westinghouse Electric Corporation under contract to the United States Bureau of Mines (Contract Number H0101262 dated Jung 17, 1970). The program was directed by the Special Systems Department of the Westinghouse, Baltimore, Maryland facility. The basic objectives of the CMRSS program were to develop and test hardware to determine the efficacy of a variety of coal mine rescue and survival concepts and techniques. These concepts were drawn from two major- sources: the Request for Proposal from the Bureau of Mines and the final report on the Mine Rescue and Survival Study conducted by the National Academy of Engineering (NAE).

Jan 1, 1971

By Lowell J. D

This paper is an outgrowth of a continuing compilation of the geology of Chilean ore deposits by Carlos Ruiz who was the author in 1965 of Geologia y Yacimientos Metaliferos de Chile which was the definitive compilation of the ore deposits of Chile. A new version was written by him in 1988, with the co-operation of Federico Peebles L, published in Geologia, Distribucion y Genesis de los Yacimientos Metaliferos Chilenos. Over the past eight years J David Lowell studied the geology of the Chilean mineral belts in connection with planning mineral exploration for copper and gold.

Jan 1, 1990

By Ron Galisky

Generalmente, las empresas mineras deben decidir si reemplazan los equipos anteriores por unos nuevos o continuan con los mismos . Los criterios se basan en el nivel de deterioro, cambios tecnológios, demandas medioambientales, o cambios de requerimientos. En ese sentido, el presente texto describe la metodología adecuada para la gestión de cambios de equipos a través de la teoría clásica del CAE donde se abordan tales problemas. Así también se plantea el uso del modelo CRU Strategies. La metodología ayuda en la planificación y gestión operativa y en los presupuestos de inversión anuales típicos en la industria.

Mar 1, 2012

By G. L. Oldright

In the first paper of this series (R. 1. 4333) on the cooperative work with the Eagle-Pitcher Mining & Smelting Co., changes in the nature of the sinter feed were measured by corresponding changes in the retorting temperatures necessary to distill zinc at the best rates; the firing schedules summarized such changes. In this paper, third of the series, are noted same of the changes in practice that were brought about by the need to treat more fused, glassy, and "hard" sinter, as the operators qualify it. Losses of uncondensed zinc were increased by adding zinc-bearing materials from which? the zinc was readily distillable to hard sinter requiring higher-temperatures for zinc distillation. The rates of zinc distillation were increased by grinding the fuel finer; there were few benefits and loss of dust on grinding the sinter finer, unless the fine ?coal and fine sinter were brought into contact by pelletizing, and the pellets made but little dust.

Jan 1, 1948

By William Escudero Simon

La Sociedad Minera El Brocal S.A. a través del planeamiento estratégico de la producción (PEP) señala el diseño, desarrollo e implementación de un sistema de costos basados en actividades (ABC, Activity Based Costing). Para implementar el modelo de costos basado en actividades ABC, se redefinió los recursos, procesos, actividades y objetos de costos de la organización. En ese sentido, el presente texto busca diseñar e implementar un sistema de costos ABC que permita ayudar en la toma de decisiones, el mejoramiento continuo de los procesos, obtener ventajas competitivas y una mayor presencia en el sector minero.

Jul 31, 2003

YEAR OF ELECTION 1913. FRANK DAWSON ADAMS Montreal, Canada. 1921. WILLIAM CUTHBERT BLACKETT Sacriston, Durham, England. 1923. GELASIO CAETANI Rome, Italy. 1929. TAKUMA DAN Tokyo, Japan. 1920. HENRY STURGIS DRINKER Merion Station, Pa. 1922. FEDERICO GIOLITTI Torino, Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1928. JOHN HAYS HAMMOND New York, N. Y. 1928. WILLIAM BOYCE THOMPSON Yonkers, N. Y. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER Washington, D. C. 1905. HENRI LECHATELIER Paris, France. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1909. ALEXANDRE POURCEL Paris, France. 1911. ROBERT H. RICHARDS Cambridge, Mass.

Jan 1, 1923

1913. FRANK DAWSON ADAMS Montreal, Canada. 1921. WILLIAM CUTHBERT BLACKETT Sacristan, Durham, England. 1923. GELASIO CAETANI Rome, Italy. 1920. HENRY STURQIS DRINKER Merion Station, Pa. 1922 FEDERICO GIOLITTI Torino, Italy. 1906. SIR ROBERT A. HADFIELD London, England 1928. JOHN HAYS HAMMOND. .New York, N. Y. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER Washington, D. C. 1905. HENRI LECHATELIER Park, France. 1931. WALDEMAR LINDQREN Cambridge, Mass 1929. JOHN MARKLE. .New York, N. Y. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1909. ALEXANDRE POURCEL Park, France. 1911. ROBERT H. RICHARDS Cambridge, Mass.

Jan 1, 1932

By Robert L. Hautala

In 1978, Congress established a series of mineral institutes for a limited time to assist financially in mineral industry education and research. Later, education and research were separated, establishing generic institutes for specialized research that transferred the former research budget from the base mineral institutes program. One of the generic institutes is the Mine Systems Design and Ground Control (MSDGC). It provides for research funding specifically for mining. Other parallel generic institutes were established in pyrometallurgy, comminution, waste management, etc. MSDGC was established at Virginia Polytechnic Institute and State University(VPI). The founding group included the University of Alabama, University of Kentucky, University of Nevada Reno, University of Idaho and University of Alaska reporting through VPI to the US Bureau of Mines (USBM) and Congress. Other universities also participated on an ad hoc basis.

Jan 1, 1996

By Jr. Blanchette, Claude Bazin, Paul Blatter

"Reporting of the gold production during a month implies to estimate the mass of gold that is processed by a mill, recovered as dorés, lost to the tailings and the change of gold inventory within the plant equipments. Carbon in pulp and/or carbon in leach tanks may contain gold inventory as large as 72 000 g (2 200 troy oz) of gold which needs to be estimated from measurements obtained from sampling the material contained in a tank. Sampling and analysis introduce measurement errors that could be systematic and/or random. This paper examines the effect of measurement errors on the estimation of the gold inventory and on the variation of the inventory in the carbon in leach tanks of the Agnico-Eagle Mines Limited Lapa concentrator. Results of the analysis demonstrate that the inventory is measured with ±10% reproducibility, while the variation of inventory used for mass balance is known with ±300% reproducibility.INTRODUCTIONThe preparation of a production report implies to reconcile measured data with the constraint of material balance over the considered period of production. The sampling and data reconciliation problems were recently reviewed by Morrison (2008) and Jansen (2009a; 2009b). Typically a production report is prepared to cover a period over which the mass conservation hypothesis can be considered valid. In gold processing plants, the change of inventory can seldom be neglected and plays a significant role in material balance calculations. This is particularly true for circuits using carbon adsorption, where the complete cycle of carbon is measured in days.In a 2000 t/d gold ore processing plant, the inventory can be as large as 140 000 g of gold in gravity concentrator bins, carbon in pulp tanks and in the electrolysis circuit. This is equivalent to the mass of gold that fed the circuit during 10 days of operation with 7 g/t feed assays. The change of inventory may therefore strongly impact the production figures and especially the plant recovery at the end of a week or a month. Despite the financial impact associated with gold inventory, few publications are devoted to the subject. Bruington (1991) and Morrison (2008) discussed the problem and stressed the need for the development of reliable methods to estimate the gold inventory in carbon in pulp or carbon in leach circuits."

Jan 1, 2011

By John C. Taylor

A resource document, prepared for the Royal Commission on the Health and Safety of Workers in Mines, which outlines aspects of occupational health and safety in the Canadian metallurgical industry has been expanded to provide examples of some practical solutions. General process descriptions are provided in conjunction with some of the major potential hazards associated with each step. Emissions to the working environment, particularly around converters, are discussed. Newer metallurgical processes, the role of automation and other advances in the metallurgical industry are described with respect to their impact on the work place. The role of staff and unit employees in providing safe working conditions in the complex metallurgical plant of today is outlined and the need for close cooperation within the human sector emphasized. The technology is available and is being applied to integrate the complex process requirements with realistic regulations to control emissions and provide a safe, healthy environment in metallurgical plants.

Jan 1, 1978

1913. FRANK DAWBON ADAMS Montreal, Canada. 1921. WILLIAM CUTHBERT BLACKETT Sacriaton, Durham. England. 1923. GELAEIIO CAETANI Rome, Italy 1920. HENRY STURQIB DRINKER Merion Station, Pa, 1922. FEDERICO GIOLITTI Torino, Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1928. JOHN HAYB HAMMOND New York, N. Y. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER Washington, D. C. 1905. HENRI LECHATELIER Paris, France. 1931. WALDEMAR LINDQREN Cambridge, Mass. 1929. JOHN MARKLE New York, N. Y. 1921. C. MCDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1909. ALEXANDRE POURCEL Paris, France. 1911. ROBERT H. RICHARDS Cambridge, Mass.

Jan 1, 1932