Search Documents

By Edward Rybinski, Serkan Dikmen, Walter Valery, Jorge Ghersi, Roberto Valle, Alex Jankovic, Javier Linares, Frank Davila

Compañía Minera Antamina is a polymetallic mining complex that produces copper and zinc concentrates as primary products and molybdenum and lead/bismuth/silver concentrates as by-products. In 2007, Metso Process Technology and Innovation (PTI) was contracted to increase SAG mill throughput by integrating and optimising blast fragmentation, crushing and grinding for the harder M4/M4A (CuZn) ores. Following the implementation of recommendations provided by Metso PTI, the SAG mill throughput increased from 2750tph to reach an average of 3600tph for the remainder of 2007. Due to continued application of mine to mill integration and optimisation philosophy, by 2010, the concentrator consistently exceeded the target of 4400tph while processing harder CuZn ores.

Jan 1, 2012

By I. M. Gordon

"INTRODUCTIONThe Hollinger tailing disposal plant is situated about 1 1/4 miles south of the mill. The area available for tailing covers 620 acres and is roughly 1 ¼ miles long by ¾ mile wide.Tailing was first deposited on the northeast section of the present site. This section, 1 mile long by ~ mile wide, sloped from northeast to southwest, the slope amounting to 106 feet between the northeast corner and the low land to the south west. The low land was wet and a considerable area was covered with muskeg up to 17 feet deep. It was drained by a creek running across the property in a southwesterly direction. Later, when more ground was needed, the low lying mining claims adjacent to the south and west boundaries were acquired to allow for expansion of the plant. This entailed some extra difficulties and expense that would not have been necessary had the whole of the present site been acquired with the original purchase.At the conclusion of milling, May 7, 1968, the site contains nearly 56 million tons of tailing. The top of the deposit is from 70 to 90 feet above the original low lying ground along the northwest, west and south boundaries."

Jan 1, 1969

By L. Xia, B. Hart, K. Douglas

In the flotation of Rare Earth Element (REE) bearing minerals, oxalic acid is reportedly acting both as a depressant and pH modifier. Testing has established the significance of oxalic acid in the flotation process however its specific role in either the recovery or selectivity of REE over their gangue minerals is not well understood. Pulp pH reduction trials with alternative acids have not shown the same effect on the REE mineral recovery or the depression of gangue phases. This work examines the effect of oxalic acid on the surface of gangue minerals (quartz and carbonates (dolomite and calcite)) in a series of conditioning tests. Gangue surface analyses by TOF-SIMS indicate that oxalic acid inhibits the transfer of secondary ions generated during the conditioning process from one mineral phase to another. In this regard, the oxalate anion acts to fix ions in solution through chelation, limiting their participation in surface adsorption.

Jan 1, 2014

By Tom Shumka

All mineral processing facilities that use girth gear driven mills need to inspect the gear teeth on a routine basis, whether it is every six months or every three years. The inspection frequency depends upon gear tooth condition, and the objective is to ensure operational integrity of the gear teeth. Conventional methods such as magnetic particle testing, visual inspection, or dye penetrant examinations rely heavily on interpretation. At best, these techniques can determine whether a defect exists, but are unable to provide information on defect severity. This paper describes the use of combined Eddy Current Array (ECA) and Alternating Current Field Measurement (ACFM) to provide a complete survey of all surface breaking indications on the whole gear tooth depth. This method accurately determines the size, length and depth of any cracks found on the surface.

Jan 1, 2012

By W. S. Urbanski, A. L. Devernoe, R. W. Stuart, M. S. Walker

"Although many investigators have successfully achieved separations using variations of a concept wherein particles are buoyed upwards against gravity in a magnetically attracted fluid, none have succeeded in separating fine particles in a manner that is practical tor mineral beneficiation. This paper describes laboratory tests and preliminary economic analyses for a new mineral separation process which provides enhanced magnetic buoyancy and separation capabilities. The process provides a means of gravity separation in a regime where conventional gravity separation is inadequate; that is for small differences in mineral densities and for very fine particles. Although early interest centers on gravity separation, the process has also been successfully used for precise magnetic separation.Tests were conducted on a variety of mineral mixtures, ore samples and concentrates including; a sphalerite ore, pyrochlore ores and concentrates, cassiterite pre-concentrates, a chromite pre-concentrate, and heavy mineral placer samples. Separations requiring high discrimination between fine particles narrowly different in density or weak magnetic properties were obtained. Of particular interest is the ability of the process to concentrate or remove oxide minerals or gangues, especially silicates. Potential applications are discussed."

Jan 1, 1985

By Daniel Gendron, Luc Morin

"Concentrate sampling is a growing concern in the world's mining and smelting industry. The main modes of transportation for concentrate to the smelter are by truck or rail car in a bulk form, thereby limiting access to sample extraction equipment. In many cases, concentrate is shipped to a smelter by several suppliers therefore requiring individual manipulation of different customer samples in a safe and reliable manner. The Heath & Sherwood Bulk Product Sampler offers this feature as well as an economical and effortless way of obtaining samples in rail cars or truck boxes.In 1994, Noranda Metallurgie in Rouyn-Noranda, Québec purchased a self contained Bulk Product Sampler to extract samples directly from inside rail cars before unloading the concentrate. After testing and comparing the results with the conventional sampling method, the bulk product sampler proved to be a practical and advantageous solution for concentrate sampling both for the customer and smelter. Since its installation at the Horne smelter in Rouyn-Noranda, the Bulk Product Sampler has been steadily used on rail cars which contain concentrates from around the world."

Jan 1, 1996

By W. Dan Hausel

"Hundreds of diamonds have been found in the United States. The majority of the discoveries occurred during the 19th century as a by-product of placer gold mining. Most of these early diamond finds have no known source, and in many cases are situated in areas unfavorable for diamond exploration based on current models that require kimberlite or lamproite to be emplaced in a stable Archean craton or Proterozoic craton margin.Diamonds have also been recovered in situ from lamproite at Murfreesburo, Arkansas, from kimberlite in the Lake Ellen region of Michigan, and in several kimberlites in the Colorado–Wyoming State Line district. Unverifed reports also suggest that diamonds may have been recovered from other related intrusions at a number of localities in the United States.IntroductionTo date, diamonds have been recovered in situ from kimberlite in the Colorado–Wyoming State Line district and from a kimberlite in Michigan. Additionally, diamonds have been recovered from lamproites in Arkansas. Diamonds have also been reported from kimberlite in Kansas, and from peridotite in New York and Maryland. However, these latter reports have not been verified."

Jan 1, 1995

By J. D. Stinnette

Traditionally, airflow requirements for diesel equipment operating in underground environments such as mines and tunnels were determined by multiplying the vehicle power by a ventilation rate that was either mandated by regulations(s) or determined empirically from known quantities. In some cases, utilization factors were further used to adjust (reduce) the total airflow calculations for a diesel equipment fleet. However, in light of the drastic reductions to diesel equipment emissions mandated by the US EPA Tier IV and EURO Stage 4 regulations, there is currently a great deal of uncertainty in the underground mining industry among those responsible for the ventilation of planned new mines or the expansion of current mines. Tier IV engine standards mandate a reduction of DPM and NOx of approximately 95%, but can ventilation rates at mines with Tier IV equipment (or equivalent) really be reduced by a factor of twenty? This paper outlines some of the factors that affect the airflow required for the ventilation of modern diesel-powered equipment and examines how they can be applied in determining a reasonable ventilation rate for Tier IV compliant equipment operating in subterranean environments.

Aug 1, 2013

By S. Y. Mostowy, P. W. M. Shibley

"When Texas Gulf Sulphur Company discovered the Kidd Creek ore body in 1964, a crash program began almost immediately for the design and construction of a modern concentrator. It was necessary to mill two distinct ore types; one containing copper and zinc, the other lead, silver and zinc minerals. The final concentrator design was to handle 9,000 tons of ore daily in three circuits. One circuit was to treat copper-zinc and another lead-zinc ore exclusively on a permanent basis. A central circuit was designed with adequate flexibility to treat either of the above ore types in accordance with planned mining schedules. Ecstall Mining Limited, a wholly owned subsidiary, now operates the mine and concentrator complexes for Texas Gulf. The mine is located 15 miles north of Timmins and the concentrator 15 miles to the north-east along Highway 101. The ore is hauled from the mine to the concentrator over a 17-mile railroad. Initial milling operations began in November, 1966.1 - ABSTRACTThis paper deals with bulk reagent handling at the Kidd Creek concentrator. The reagent section at Kidd Creek has operated excellently since milling began in 1966. The bulk handling techniques are satisfactory. They have contributed substantially to good working conditions, economical practices and metallurgical efficiencies. The bulk handling features described should be considered in existing and proposed concentrators."

Jan 1, 1970

In-Country Business Development Agenda ?Siting/Permitting/Operational Planning ?Securing, maintaining, enhancing social license to operate ?Biodiversity conservation and ecosystem services ?IFC Performance Standards ?Environmental, Social, Risk Governance (ESG) ?Climate change plan

Aug 1, 2013

CI, Data and Data Systems Road Analysis Control Quick and simple manual Analysis Case study Visual relation of analysis

May 1, 2013

By P. B. Marchant

"Based on laboratory and pilot scale continuous biooxidation of complex sulphide concentrates, commercial processing design and scaleup considerations are discussed. Capital and operating cost estimates for commercial biohydrometallurgical operations are summarized and potential applications of biotechnology are discussed. Biooxidation as an oxidative pretreatment alternative to enhance precious metals extraction from refractory sulphide concentrates in stirred tank reactors has received considerable attention recently due mainly to advances in the practical applicability of the process. Biooxidation of sulphides is certainly not a new process, however, application and control in large scale hydrometallurgical operations to treat refractory sulphides remains conceptual and the limited data available is restricted to relatively small laboratory and pilot scale operations. It is the intent of this paper to indicate scaleup and plant scale process design considerations for commercial bioleach circuits, based on recent operating experiences with laboratory and pilot scale continuous bioleach systems. An indication of the expected range of applications will be presented parameters for optimization will be discussed."

Jan 1, 1986

By M. Moghadami

Design and construction of underground openings are associated with many uncertainties with regard to input data. In the construction process of underground openings various levels of risks exist and these affect the safety and profitability of the project. The development of underground openings can be broadly categorized into three major phases of data collection, design, and construction. A significant level of uncertainty is associated with some of the key parameters involved in the aforementioned development phases. Moreover, it is very difficult to evaluate and quantify the effects of uncertainties on the underground project construction process. Additionally, the interactions between important risk elements are typically not well understood. The intention of this study is to develop a general risk model for underground opening projects located in soils and weak rock masses. The goal of the research is to identify and quantify important geotechnical risk elements. Moreover, a weighting procedure will be proposed for the identified risk elements. Finally, all important risk elements will be assembled into a general model with emphasis on geotechnical parameters. The final objective of this study is to apply the proposed model to a real underground project scenario and verify it for actual field conditions. The proposed model, once calibrated properly, will provide a useful support tool for the decision making process.

Aug 1, 2013

By Zhigao Xu, Ruan Chi, Zhenyue Zhang, Yaoyang Ruan, Zhengyan He

Thorium is frequently the main radioactive element in rare earth ores and is a resource that can potentially substitute for uranium. Thorium must be separated from rare earths in order to obtain products with low radioactivity. There are abundant resources of thorium in the rare earth ores in China, especially in Baiyunebo mixed ores. As an associated element coexisting in rare earth ores, thorium is, or can be, separated from rare earth concentrate, iron concentrate, as well as from waste water and slag to achieve recovery of thorium. The methods of separation include ion exchange resin, liquid-liquid extraction, and liquid-solid extraction. TBP extraction has been the main method applied to separate thorium by domestic and foreign scholars. This paper presents a comparison of different processes for the separation of thorium from rare earth ores, especially Baiyunebo mixed ores, single bastnaesite and monazite ore, and provides suggestions for the future recovery of thorium resources.

Jan 1, 2014

By Parsons. Robert B.

"Starting this year, corporations that conduct business in Ontario face a new tax a corporate minimum tax. This tax is in addition to the myriad of other taxes that make up a corporation's total tax burden including federal and provincial capital 1oXJ!S, payroll tax and sales taxes. Mining companies with gross revenues in excess of $10 million or total assets exceeding $5 million may be liable for this new tax. IntroductionOn December 8, 1993, the Ontario government introduced legislation to implement the corporate minimum tax (CMT promised in its May, 1993 budget. There are very few differences between the final legislation and the budget proposals.The CMT is effective for taxation years commencing after 1993. Subject to certain specific exemptions (detailed below), the tax applies to all corporations liable for Ontario Corporate Income Tax that have either gross revenues in excess of $10 million or total assets in excess of $5 million. These measurements apply to the aggregate gross revenues and total assets for all corporations in an associated group and a corporate partner's share of partnership assets and revenues must be included in the determination.In essence, the CMT is an income tax that is based on financial statement profit instead of an income amount that is determined separately under a statute. Accordingly mining companies (including so called ""junior"" exploration companies), which traditionally sheltered their taxable income by claiming generous exploration and development deductions, could find that they have a CMT liability."

Jan 1, 1994

By R. C. Urquhart

Since the first use of the electric arc furnace Henri Moissan (1892) and its use by Paul Hérholdt (1902) to melt steel, it has been successfully used as a pyrometallurgical smelting tool in the production of calcium carbide, iron, ferrous and non-ferrous alloys. Commercial forms of the electric arc furnace have evolved from round, single-phase single electrode units to rectangular three electrode three-phase units to round three electrode three phase units and ultimately to rectangular six electrode three-phase units. DC electrical supply has also been used to replace the three phase power supplies in some cases. This paper examines how these electric arc smelting furnaces have evolved in size, efficiency and configuration within the constraints of the smelting process, electrodes and electrical power supply equipment.

Jan 1, 2014

By Md. Rashedul Islam

Magnetic data was collected from the Yeoju historical sites using the fluxgate gradiometer through six sites & several grids. We measured the vertical gradient by the FM256 Fluxgate gradiometer. The readings were logged every half meter. The obtained data were processed and treated to introduce a high quality magnetic image. The gradiometer results defined various positive and negative magnetic anomalies, which revealed the existence of several archaeological features of different shapes and sizes. The study of the process magnetic images give us a concept that the subsurface features are caved shape stone chamber tombs, burial mounds, deep room structure, Yeoju mausoleum, pagoda?s square foundation stones, walls etc. All these are superior work of early Goguryeo inheriting orthodox Silla style. So, the study area may have great archeological interest.

May 1, 2009

By George Dogbe

Open pit optimization forms the basis of mine design, production planning and construction of mine facilities. The negative effects of this phase may include substantial reductions in ore recoveries, relocation of waste dumps and surface infrastructure, extraction of unwanted waste, with a cumulative effect on mine value reductions. As a result, this area has received significant research focus using linear and dynamic programming, heuristic, genetic and stimulation algorithms and the graph theory. These algorithms are derived from rigorous mathematical models, but they are built on the assumption that all the periodic production capacities are extracted at the time of analysis. This assumption weakens the models because mining occurs over significant time period. In order to develop a comprehensive model that accounts for the timing of material extraction, the current models, which are built on the economic block value (EBV) concept, must be modified to account for time. In this paper, the authors develop a model of the optimization problem using the 2-D Lerchs-Grossmann?s optimization algorithm. This model is used to investigate the effect of periodic discounting on the optimal pit layout design by designing an integrated pit optimiser (IPO) that incorporates ?production scheduling?. IPO uses the ensuing discounted economic block value (DEBV) as a basis for the pit optimisation process. The time-dependent model is compared with a time-independent model. The results show that discounting has no effect on the optimal pit contour although the reported pit value is overstated if the EBVs are used instead of the DEBV. The authors, however, believe that this conclusion may not be general and could have been influenced by the nature of ore body geometry and the proposed mining strategy.

May 1, 2004

By P. J. Foster

Bowtie analysis has recently emerged as a technique of choice that can be used when looking specifically at major hazards in the mining industry. A Bowtie diagram is a graphical means of assessment that focuses on identifying all the specific causes and consequences of major events, from which all the ?pre-event? and ?post-event? control measures can be identified. From this critical control measures can be identified and monitoring/assurance systems can be established. It is this assessment of control measures and their effectiveness that replaces the more traditional evaluation of risk (using matrix-based approaches) based on the fact that risk is a function of control ineffectiveness. This is a major difference with traditional risk assessment where all too often control effectiveness is assumed. This paper summarises the Bowtie analysis process and outlines one specific case study where the technique was used on the unwanted event of a collision of a haul truck and light vehicle in an openpit mine. Although more effort is required in undertaking the assessments, control assurance provided this way will go a long way in ensuring that risk assessments and major hazard management become much more effective in practice.

Aug 1, 2013

By Michael Nicol

A quantitative description of hydrometallurgical operations depends primarily on an understanding of the kinetics of the chemical and physical processes that take place in such operations. This paper will review the current status of kinetics in hydrometallurgy in terms primarily of the author’s experience in diverse unit operations. A distinction will be made between the popular use of models based on limited kinetic data and mechanisms which reflect the actual elementary chemical or physical steps involved in an overall process. Several examples will be used to illustrate this distinction. The proliferation of published papers of declining quality has resulted in the bequest to later researchers of outdated and often incorrect conclusions by a process that is often difficult to reverse. Some examples of these mysterious concepts will be examined and hopefully reversed. Finally, several examples will be given that identify significant gaps in our understanding of the kinetics of important processes that remain unresolved.

Jan 1, 2014