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By C. M. Marquardt

The materials handling systems in the large concentrating plants have required the employment of a considerable number of workmen, many of whom had very little to do except to act as watchmen to avoid bad spills at belt junctions and to operate tripper cars, shuttle belts, etc. Much time also was spent in watching bins to make sure they were properly filled. Approximately four and one-half years ago the author, Yin coopera¬tion with the engineering and supervisory personnel of The Anaconda Company at Anaconda, Montana, began to give this problem serious consideration. Prior to this the author had developed, at the request of The Anaconda Company, a transistorized resistance-sensitive probe relay system for detecting the level of ore in bins. With this system cables or chains were suspended from insulators above the bins and were of suitable length to determine the elevation of the ore in the bins.

Jan 1, 1962

By David C. Grant

During in situ uranium mining using ammonium bicarbonate lixiviant, the ammonium exchanges with cations on the ore's clay. Mter mining is complete, the ammonium may desorb into post-leach ground water. For the particular ore studied, other chemicals (i.e., uranium and selenium) which are mobilized during the leach process, have also been found in the post-leach ground water. Laboratory column tests, used to simulate the leaching process, have shown that aluminum chloride can rapidly remove ammonium from the ore and thus greatly reduce the subsequent ammonium leakage level into ground water. The aluminum chloride has also been found to reduce the leakage levels of uranium and selenium. In addition, the aluminum chloride treatment produces a rapid improvement in permeability.

Jan 1, 1982

By Sun K. Kim

Hydrometallurgical processes are not free of environmental regulations. A clear understanding of the regulations under which the minerals industry operates delineates processing requirements at early stages. This paper deals' with federal environmental regulations with emphasis on the hazardous waste regulations promulgated in May, 1980. The procedure of EP toxicity test and an example of the test are described. Brief account is given of the current trend and future outlook of regulations.

Jan 1, 1982

By T. E. Wilson

In conjunction with experiments to improve the particle size preparation of coal bore cores prior to washability testing, discrete-event breakage of coal, shale and homogeneous low-strength concrete cores was studied. Breakage of individual size classes by drop-shatter and by incremental tumbling in an end-over-end hand-driven tumbling cylinder revealed systematic changes in the breakage function, namely, that breakage in any size class diminishes as the number of events increases. The effect of the fines removal enhances the breakage of harder material (having lower grindability indices), but appears to have less effect for softer material.

Jan 1, 1998

By Alejandro Prieto

Traditionally, Mexico has been a mining country. This industry has played a very important role in our country's development, creating jobs, integrating geographical regions - generally very remote from urban communities - and, an essential factor in our present day economy, generating an influx of foreign currency. The Fluorspar mining industry's development started in the 1920?s, but it was not until World War II that its exploitation became consistent and started growing. During the last few years, Mexico has become the world's leading producer, with an annual output of more than one million tons, which directly generates over 3,000 jobs. The actual proven reserves can guarantee fifty years of production at this same annual rate, and it is due to this fact that the producers have not increased their reserves. However, there is concrete information of the existence of several deposits, extending from the northern border to the gulf of Mexico, forming the "Fluorspar Belt? in Mexico.

Jan 1, 1986

By C. Pomeroy, J. Weyer, J. Brune

"Mining began in the Erzgebirge (“ore mountains”) region of Saxony, Germany more than 800 years ago, and extensive underground workings cut through the entire area. Some of these old workings are still used today: not for production, but for offering an underground venue for research, tourism and university teaching. One example is the Reiche Zeche mine at the Technische Universität Bergakadamie Freiberg which hosts one of the oldest mining engineering programs in the world. It is imperative to keep all active mine workings well ventilated to make the mine safe for students, visitors and researchers. Since the mine workings at Reiche Zeche are so vast, extensive and, to a large extent unexplored and unmapped, it has been difficult to provide a complete, functioning and adequate mine ventilation model for this mine that accounts for all known and unknown leakage air flows. Researchers at the Colorado School of Mines have cooperation with their colleagues at Freiberg to establish a mine ventilation network model based on a limited number of air readings in known and accessible drifts. In order to balance the measured air quantities, leakage flows were quantified and mapped by comparing input and output flows of mapped drifts, and modelled using Ventsim Visual, a powerful visualization software package. The resulting mine ventilation model is used to locate and quantify the leakage air flows and to examine how much air is lost in each area. With this model, ventilation changes and improvements underground can be documented reflected in the model. This enables the Bergakadamie Freiberg to project air changes required for scientific experiments and to set up mine ventilation in specific areas and for specific needs. The model also enables better ventilation control and monitoring than before. Finally, the model can be used to predict ventilation changes and escape way contamination in case of a fire, ground fall or inundation in the mine. The latter becomes important as the lower mine workings are often flooded during spring runoff, which has created uncertainty about mine ventilation in the past. HISTORICAL BACKGROUND The discovery of silver, lead, zinc, tin and other valuable metal ores in the Erzgebirge region of Saxony, Germany began in the12th century and started a mining boom than lasted for centuries. Surface mines quickly developed underground to access the higher grade veins. Explored by the early geologists and driven by the ingenuity of the miners, the underground works expanded vastly throughout Freiberg and the surrounding region. Development followed the highest grade veins, and engineers developed solutions to drain water and provide limited ventilation to the underground workings. Still, engineered and planned ventilation was usually not a priority in the development of a new drift, which today makes ventilation modeling a significant challenge."

Jan 1, 2015

By Donald J. Worth

When Eugene Bailey asked me to contribute to this session on "Canadian exploration - 1976", it took a little coaxing before he got me to agree. My immediate reaction was, what could i say about Canadian exploration that already had not been said a hundred times in the past few years; secondly, why include a banking person in such a discussion? Everyone knows banks only come into the picture after the discovery has been made and feasibility well established and validated. Rather than wrestle with these misgivings, I decided to take the easy way out and go on blind faith in Eugene - that is, he asked me so he must think that I could come up with some useful thoughts and at least touch upon some of the pros and cons of exploration in Canada. The object of the whole exploration exercise is to Find economic deposits, once they are found, one cannot really move them elsewhere to mine them. It follows, therefore, that we should really be speaking about the pros and cons of mining In Canada and my treatise will eventually lean in this direction. In any event and before getting down to the pros and cons, let us take a quick look at the history of mineral resource development in our country since the end of world war II. At that time, we were producing well under one billion dollars worth of mineral products including hydrocarbons.

Jan 1, 1976

By W. J. Garmoe

The Carr Fork mine is located approximately 50 kilometers southwest of Salt Lake City, Utah, in the Bingham or West Mountain District, adjacent to the Bingham open pit copper mine. Applied geology at Carr Fork, by Anaconda Minerals Company personnel, includes detailed geologic mapping and sampling of underground workings, logging and sampling of drill core and cuttings, and the preparation and posting of geologic maps and cross sections for geologic interpretation, ore reserve calculation, mine operations, and long range planning. Accurate and easily understood graphic recording of Carr Fork geology is essential for optimum use by operating and engineering personnel. The design and implementation of exploration, development and definition drilling programs, research into geological spatial relationships, and analysis of structural complexities of the Carr Fork deposit are also integral parts of the applied geology program.

Jan 1, 1992

By Ron VanRiper, Ben W. Burdett, Randy A. Ynchausti, Jeff D. McKay, Dan Lampshire, Thomas W. Toronto

An adaptive process control system was installed in Cortez Gold Mines Mill #2 Grinding Plant in Nevada. The installation, commissioning, and testing of the system took approximately 80 manweeks, but final test results show that the system paid for itself through increased throughput within two weeks of commissioning. Both crisp and fuzzy rules are used in the expert rule base which is also integrated with continually adapting neural network models. The expert rules and models are used by predictors, and optimizers to allow the control system to provide optimum process performance under continually varying feed conditions. The selection, installation, rule and predictor configuration, and statistically verifiable testing of the control system in the Cortez Gold Mines Mill #2 Grinding Plant is described in the paper.

Jan 1, 1999

By J. M. Tranquilla

EMR Microwave has developed several unique processes for the pretreatment of refractory gold and copper ores. This report describes a recent large scale pilot project involving a carbonaceous gold-bearing whole ore. Pilot plant testwork conducted jointly by EMR and Bateman Engineering Inc. has shown that 90+% cyanide soluble gold recovery is obtainable from refractory (sulphide and carbonaceous) Carlin, Nevada gold ores. Typical cyanide soluble gold recoveries for untreated material is 20%. AC energy consumption was found to be between 58.l kWh/ton and 15.5 kWh/t for an assumed heat recovery of 50% and 80% respectively. The plant was operated at reduced temperatures ( 400°C) from previous testwork on similar ore at 600°-700°C.

Jan 1, 2000

By Andreas Rubo, Stephen Gos

In the days of increasing environmental and safety awareness many efforts have been made to prevent losses of both an evident economic nature and also less obvious losses. These losses could be associated with damages due to negative impact on the environment and also people coming into contact in a broader sense with any toxic chemical. This paper deals with how cyanide can be applied in a responsible manner at a modern gold mine. Responsible application is achieved by minimizing losses of reagent and avoiding negative impact on the environment as well as adopting a Responsible Care philosophy to the application of cyanide. It becomes evident that this is quite a complex system with a greater commitment than avoiding reagent losses for economic purposes.

Jan 1, 1997

By Hans von Michaelis

This paper examines the process options available for treatment of "refractory" gold ores. As more and more of the easily leached oxidized gold ore zones are exhausted, the pressure is on to find more economical ways of treating refractory gold ore deposits. Historically, refractory ores were generally concentrated, e.g. to make a flotation concentrate that could be roasted. A major development is taking place in the USA in which ores from which gold cannot be concentrated well by flotation are being treated using whole ore oxidation processes prior to cyanidation. Refractory gold ore treatment processes are generally expensive to install and operate. Thus, for a refractory gold ore project to be economically viable, the grade must generally be higher than for free milling gold ores.

Jan 1, 1993

By Kathleen A. Altman, Kevin Hegerle

FMC Gold Company start.ea processing ore at their Paradise Peak Mine in 1986. Gold, silver and mercury haye been produced from the Merrill-Crowe milling circuit and from heap leaching. There are three heap leach circuits, Paradise Peak, Ketchup Flat and County Line. The Paradise Peak and Ketchup Flat heap effluent solutions are routed into the zinc precipitation plant which is associated with the mill for recovery of the precious metals. The County Lne hea lech circuit is a stand-alone operation, again with a zinc precipitation recovery circuit. The mill was shut down in May, 1993 due to depletion of ore reserves with the remainder of the heap leach ore due to be placed on the leach pads by late summer of the same year.

Jan 1, 1993

By N. Vayenas

Modern mines possess a wide variety of capital intensive equipment. Equipment failures and the associated down time contribute significantly to the overall maintenance, operating and production costs of a mine. Reliability investigations are becoming a standard practice, as the equipment becomes more complicated and the effective use of resources is critical for achieving higher productivity and mine safety. In view of the recent global initiative for sustainable development in the mineral industries, reliability of capital intensive machinery should be considered as a key indicator for sustainable development and growth. This paper discusses the application of equipment reliability as a sustainability indicator and proposes a methodology for its practical use. Reliability of equipment systems is useful for product life cycle assessment, mine performance measurement and evaluation.

Jan 1, 2007

By T. R. Ellis

The author is the leader of the Extractive Industries Task Force of the International Valuation Standards Committee. The Task Force has developed an Extractive Industries section for inclusion in the International Valuation Standards (IVS). The Extractive Industries Guidance Note provides comprehensive standards for valuation of all minerals and petroleum industry property types for all valuation/appraisal purposes. The document is scheduled for release as an exposure draft for public comment by December 2003, then it will be finalized for publication in the IVS in mid-2004. This paper discusses the content and philosophy of the Extractive Industries Guidance Note within the context of the framework of the IVS. It also discusses the international implications and implementation of this IVS addition.

Jan 1, 2004

By M. Khandrika, B. K. Parekh

Column flotation has proven to be the most effective technique for the flotation and recovery of ultrafine coal. The commercial application of columns in the coal industry is steadily increasing (Parekh et al., 1990; Yoon et al., 1992). For the flotation of coal or mineral air is used for generating bubbles. Using a conventional flotation cell, Miller and Mishra (1985) compared froth flotation behavior of fine coal using air, nitrogen and carbon dioxide gas. They concluded that carbon dioxide gas provided a higher rate of recovery and a lower ash content. The objective of the present study was to investigate the effect of various gases such as compressed air, nitrogen, argon, and carbon dioxide on the column flotation of fine coal.

Jan 1, 1999

By V. de Ruiter

In the northwestern part of the Netherlands lies the deepest solution salt mine in the world. The company operating the mine is Frisia Zout bv (part of the K+S group). Extracting the NaCl from caverns at a depth of nearly 3000 m has a lot of challenges. Continuously monitoring, among others, the flows, pressures and salt concentrations is necessary to safely and economically mine the salt. A system has been set up at Frisia to be able to monitor the data from a distance. Data has been put in graphs to monitor the trends daily. All gauges are also continuously monitored to maintain accuracy. With this system a better understanding of the mining process has been made and has led to many optimizations.

Jan 1, 2008

By Gh. Crutu

The handling of radioactive waste deposits from factories that produce chemical fertilizers is a difficult problem, but has a great significance for soil quality and for the environment. The Romanian legislation has produced law and normative acts concordant with EU regulations for prevention and protection, and also for environmental contamination control with radionuclides. The soils and agricultural plants in the vicinity of phosphogypsum deposits are radioactively contaminated; the annual variability of the respective radioactivity values is demonstrated by annual records. Residual radioactivity monitoring determines the presence of radioactive ions in the soil and cultivated plants: wheat, maize, sunflower, as well as the spontaneous flora. The results obtained lead to the conclusion that ecological restoration works must be executed for degraded soils due to impacts of radioactive materials.

Jan 1, 2007

By M. W. Chanda

This paper presents the development of a rock-creep measuring apparatus using air as the initial pressure source. Servo-controlled machines can and have been used for time-dependent property tests. However, the long-term nature of some tests makes essential the complete independence of stress-maintaining equipment from main power sources or continuously running hydraulic pumps. The main objective of this paper is the development of a creep testing machine that is free from interference arising through power supply interruptions or mechanical maintenance normally associated with many compression testing machines. To achieve this, a compressed-air power source was used to drive a compression ram. A few trial results obtained and analyzed using the transient creep law are in reasonable agreement with the general creep law.

Jan 1, 1993

By Hélio Blak

The Paranapanema Group was created in February 1996 when a group formed by the Brazilian pension funds acquired four companies dealing with nonferrous metals. The new Paranapanema Group, basically related to the tin and construction business, became the sole Brazilian primary copper producer, the second zinc producer and one of the most important producers of copper products, mainly tubes and fittings. To put together such different companies, managed before by family groups and with different cultures and principles, was and still is a big challenge. The strategy of developing and consolidating it as an homogeneous group is based in three pillars: an increase in production, quality and technological improvements on products and market mix and a permanent cost reduction program, using all the potential synergies founded.

Jan 1, 1998