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By Martin Grenon

This paper presents two case studies where fracture set orientation was quantified using three methods: a simple fracture pole grouping, a Fisher distribution and a Kent distribution. The three fracture orientation representations were then used as inputs for kinematic slope stability analysis. Differences showed up in the probability of sliding for all instability modes considered.

Aug 1, 2013

The integration of mining and mineral processing technologies into new advanced mining systems is considered to offer several benefits, including selective mining, reduction in waste, increased productivity, flexibility, and improved resource utilization. This paper focuses on underground hardrock mining and the integration of pre-concentration technologies into future mining systems as representing realistic, shorter-term integration options. Control of fragmentation to optimize grinding, pre-concentration of ores, in situ leaching, and modular mining/mineral processing systems are possible with existing technology. Current research is directed toward development of integrated underground systems that minimize surface activity and minimize or eliminate surface waste disposal. Results from a simulation model of an integrated underground pre-concentration system are presented.

Jan 1, 2002

By T. H. Patching

This paper provides a review of the available information on the origin and mechanisms of the release of gas from coal seams. With the opening up of new mines in Western Canada and the increased mechanization of underground coal mines, the study of gas emissions is of increasing importance in providing safe working places underground.

Jan 1, 1970

By J Zhou

Based on the mineralogical characteristics and mineral processing techniques required, gold ores can be classified into 12 types, including gold placers, quartz vein-lode ores, oxidized ores, silver-rich ores, iron oxide copper gold ores, porphyry copper gold ores, iron sulphide ores, arsenic sulphide ores, antimony sulphide ores, bismuth sulphide ores, telluride ores and carbonaceous sulphide ores. The bulk mineralogy and gold deportment of each ore type is different and may have a significant impact on ore processing and metal extraction. This paper summarizes the bulk mineralogy and gold deportment in some major types of gold ores and discusses the potential impact of gold deportment on gold metallurgy.

Jan 1, 2011

By J. Fournier, D. Fortin, F. Robichaud

Since milling began in 1988, the Laronde mill has been expanded several times, the most recent, increasing the milling rate from 5 000 to 7 000 mtpd. Laronde uses SAG/ball mill grinding followed by copper and zinc flotation circuits. A cyanidation/Merrill-Crowe process recovers the remaining gold and silver in the flotation tails in order to cope with high silver/gold ratio associated with the discovery of the Penna shaft. Since the commissioning of the Merrill-Crowe refinery in 2000, several modification and expansion projects were performed to reduce health and safety hazards. Remarkably, several of these improvements have contributed at increasing productivity and Net Smelter Return of the refinery while reducing worker's injuries. In 2004, the refinery was audited to evaluate and quantify the circuit performance. Metallurgical and mechanical operating conditions of the refinery are now understood and areas for further improvements are well defined. This paper describes some of the factors that have contributed to this improvement and describes how ergonomics and recovery can further be improved.

Jan 1, 2005

By Kazutoshi Haga, Ariunbolor Narankhuu, Ariuntuya Battsengel, Yasushi Watanabe, Altansukh Batnasan, Akita University

"Rare earth minerals are usually concentrated by flotation, magnetic or gravity separation methods to produce concentrates that are subsequently leached with hydrochloric (HCl), sulfuric acid (H2SO4) or nitric acid (HNO3). About 75 % REEs are lost in gypsum by-product when apatite is dissolved in H2SO4, whereas more than 80% of REE can be extracted from the apatite using HCl and HNO3 leaching processes, respectively. Therefore, the main aim of this study was to find an efficient process of dissolution of rare earth elements (REEs) from apatite ore by sulfuric acid solution due to its lower cost. In order to optimize the dissolution process, effects of different parameters, namely, concentration of H2SO4 (0.05 – 6 M), solid/liquid phase ratio (1:50 – 1:100), temperature (20 – 80 ºC), agitation speed (300 – 900 rpm), and leaching time (0.5 - 6 h) on the dissolution of REEs from apatite ore were examined in various intervals. The contents of main REEs in the apatite ore used in this study were (as % wt): 3 % La, 6 % Ce, 0.6 % Pr, 2.1 % Nd, 0.2 % Sm and 0.3 % Y. X-ray diffraction (XRD) analysis identified fluorapatite and phlogopite as main minerals in the ore. The results obtained from leaching experiments showed that more than 85% of REEs were dissolved from the apatite ore under the optimized conditions, which were: 1 M H2SO4, particle size of -150 + 100 µm, S:L phase ratio of 1:50, agitation speed of 500 rpm at 20 ºC for 1h. The XRD analysis revealed that main mineral compositions of the residues from 1M and 6 M H2SO4 leaching are gypsum (CaSO42H2O) and hemigypsum (CaSO40.5H2O), respectively.INTRODUCTIONThe term rare earth elements (REEs) denote the group of 17 chemically similar metallic elements consisting of the 15 lanthanides, plus yttrium (Y) and scandium (Sc) in the periodic table. These metallic elements are generally divided into two sub-groups; (1) the cerium sub-group, which is called “light rare earth elements” (LREEs), includes the elements from lanthanum (La) to europium (Eu), and (2) the yttrium (Y) sub-group elements, which are known as “heavy rare earth elements” (HREEs), are the remaining lanthanides from gadolinium (Gd) to lutetium (Lu) plus yttrium (Gupta and Krishnamurthy, 2005). The REEs occur together in the minerals due to their chemical and physical similarities, which cause problems of separating them from one another (Abreu and Morais, 2014). Although REEs are relatively abundant in the earth’s crust, they are typically dispersed and rarely occur in concentrated forms, making them economically challenging to obtain. There are a wide variety of rare earth minerals, however economic deposits of REEs in mining are bastnasite (La, Ce) FCO3, monazite (Ce, La, Y, Th) PO4, and xenotime YPO4 (Binnemans, 2013; Xie, et al, 2014). Due to the unique physical, chemical, catalytic, electrical, magnetic and optical properties of REEs, demand of these elements has increased dramatically with the advent of new technologies in electronics, communication, construction, energy and medicine (Jordens, et al, 2013). Since 1990, China has provided about 90 % of REEs worldwide. Japan and United States are the largest consumers of China’s REEs. In 2010, China announced to reduce REEs exports to Japan, as it tended to increase prices of REEs and to reduce a stable supply of REEs in the world market (Humphries, 2013). Therefore, there has been an increase in recent exploration activities intended to reveal new commercial sources of REEs and to bring them into production (Antico, et al, 1996). Apatite is an important host mineral for REEs in igneous and metamorphic rocks and can be used as an ore for those metals (Kanazawa and Kamitani, 2006). Apatite is also the main source of phosphate fertilizers and phosphoric acid (Habashi, 2013; Emsbo, 2015)."

Jan 1, 2016

By G. C. Lipsyy

ALL mineral production? of Can11.da is transported in a mine car at some stage during its extraction. There are as many types and varieties of mine cars as there are of mines. Many of the cars in use were developed in the blacksmith shop. Others were designed by engineers and improved by the mine foremen and the mechanics. Every mine car has the ideas of miner, blacksmith, mechanic, and engineer incorporated in it. Many of these ideas are not generally known. This paper was written to make at least some of this information available to the mining industry. In drawings, tables, and notes, it gives all the important details pertaining to the cars. It .does not recommend any particular type of car for any particular piece of work, nor does it present drawings from which a car can be built. It gives the engineer or master mechanic information on many cars which he can apply to his own particular problems. It is hoped that this information will be of use to mine operators. If a few new ideas are conceived as a result of the paper, the author will feel that the effort of compiling it has been worth while. In order to obtain the data for the preparation of the paper, a questionnaire, copy of which is here reproduced, was sent to all the operating mining companies in Canada. An accompanying letter briefly explained the purpose of the paper and asked for co-operation in furnishing as complete information as possible.

Jan 1, 1945

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By G. Morin, F. Chiesa, B. Duchesne

The Quality index is a useful tool allowing to assess the metallurgical quality of aluminium AlSiMg foundry alloys (A356/357). Its value is calculated from the ultimate tensile strength and elongation; it increases with the metallurgical quality of the casting, i.e. with finer dendrites, lower microporosity and inclusion count and lower iron content. This Quality index does not depend on the degree of temper applied during the heat treatment (aging time and temperature). After defining the Quality index, it will be explained how it can be predicted from the knowledge of the local solidification conditions obtained from modelling. The paper will then present four case studies of castings for which the prediction of the Quality index by modelling was made. These case studies from different authors will involve the three most common casting processes used for producing high integrity aluminium castings, namely: sand casting, permanent mould casting and investment casting (lost wax). In all cases, the accuracy of the prediction will be assessed by comparing the predicted Quality index distributions to the experimental values based on the published measured values of the local tensile properties.

Jan 1, 2006

By J. A. Folinsbee, Andre Robitaille, Tony Y. Chong

"Conventional crushing and grinding is followed by gravity concentration to recover free milling gold. Refractory gold, finely disseminated within the pyrite and arsenopyrite matrix, is recovered by flotation followed by pressure oxidation, cyanidation, and cementation. Non-refractory gold is recovered by cyanidation/CIP processing.A comprehensive test program aimed at improving flotation recovery was initiated in June 1995. Plant testing indicated that flotation tails value could be significantly reduced using mechanical flotation cells. Based on these test results, a flotation circuit that incorporates one of the three existing flotation columns followed by mechanical scavenging and cleaning was developed. Detailed engineering was completed in September 1996. Construction started in February 1997 and was completed in 3 months at a cost of $3.2 million. An on-stream X-ray analyzer was installed to provide real-time arsenic and iron analyses and inferred sulphur value on some of the flotation streams.The new flotation circuit proved to be an instant success. Flotation tails values were reduced by 27%. Final tails solids and solution was reduced from 0.035 to 0 023, and 0.0014 to 0.0006 oz/ton Au, respectively. Based on a mill throughput of 1,620 stpd this decrease in tails value will result in an increased gold production of 7,500 ounces per year. The payback for the project is estimated to be around one year.This paper describes the evolution of the project from bench scale testing to commissioning. Also, the operational and economic impacts on down stream processing are highlighted"

Jan 1, 1998

By J. T. Sims, C. E. Karayannopoulos

Today's rare earth industry is undergoing significant and rapid evolutionary change toward greater reliability and diversity of supply, increased security of supply chains, and better price forecasting. Technology innovation is reducing rare earth production costs while decreasing the impact of producers on the environment. Advances in rare earth material science are reducing the need for relatively scarce heavy rare earths (HREEs) in high-performance neodymium-iron-boron (NdFeB) permanent rare earth magnets and opening the NdFeB magnetic market space for a broader range of downstream applications. Rare earth producers such as Molycorp are increasingly able to offer long-term supply agreements with forward price predictability, something that has not been the case for many years. All of these trends are helping to restore the confidence of customers and other stakeholders in the rare earth space. That increased confidence is likely to bolster global demand for rare earth materials and expand innovative utilization of these remarkable materials.

Jan 1, 2014

By O. W. Borgeson, D. K. Honsberger, R. T. Bell

The Scully Mine, situated in the Labrador Trough near the Quebec-Labrador boundary, is one of the world's largest continuous ore deposits. This paper outlines the sequence of the mining operations from the planning stages to the delivery of the ore to the crusher at an average rate of 50,000 tons per day, 7 days per week. The principal equipment required to maintain this production rate includes four 12.\1.1-inch rotary drills, seven 8-cu.-yd electric shovels and a fleet of large haulage trucks. Particular attention is given to grade control, programmed by computer, drilling and blasting techniques and operational aspects inherent with open-pit mining in Canada's North.

Jan 1, 1969

By Paul Hughes

Purpose of Research ? What are the loading mechanics of paste against barricades? ? What is the capacity of the composite paste fill fences? ? Based on the loading mechanics of the paste, do the fill fences pose a risk of failure? Outline ? Glossary of Terms ? General Introduction ? Research Methodology ? Site Description ? Instrumentation Program ? Results ? Analysis ? Conclusions ? Recommendation for Future Work

May 1, 2008

By Adrian Dance

The Antamina orebody is a geologically complex, polymetallic skarn located in the Peruvian Andes. A range of copper and copper-zinc ores are campaigned separately through the concentrator producing copper and zinc concentrates as well as lead and molybdenum by-products. Ore type classification at Antamina is based on chemical assays; geological or lithological variations are not considered. Consequently, each ore type demonstrates a wide range of concentrator performance. Antamina is currently implementing a system to track ore movements from the shovel face to the concentrator. Relatively sophisticated models of the ROM and coarse ore stockpiles ahead of the mill will be used to account for the variable delay between mining and milling. One of the numerous benefits of ore tracking is the ability to directly associate the measured concentrator performance with a physical location in the orebody. Using existing mine planning software, three-dimensional models can be created of such performance measures as metal recovery, concentrate quality, operating cost and reagent consumption. Such a database of information allows the true value of different ore sources to be determined. The value of an ore source is conventionally measured as metal content (individual or combined ?equivalent?) with a cut-off grade applied to indicate some base level operating cost. However, the true value of an ore source should include dynamic factors like haulage cost, reagent use, smelter penalties and even prevailing metal prices. If an ore source is considered from all perspectives rather than simply its potential to deliver value, the concept of ?ore? becomes more flexible. Any ore source that reveals itself to be unprofitable can be eliminated from the mine plan or possibly blended with others to improve its value. The ability to predict mill performance ? and thereby profitability ? is a powerful tool. In an operation such as Antamina, where managing ore sources, campaigns and the delivery of a variety of concentrates in a narrow timeline to customers is a daily challenge, prediction is the key to success and improved efficiency.

May 1, 2003

By Roger V. Pierce

IN the last few years, much study has been devoted to increasing stoping efficiency. The reasons for this are shortage of manpower, shorter working hours, operating regulations, and shortages of essential materials. More efficiency in mining methods is needed to offset these adverse factors. In the past, attention has been centred upon haulage, hoisting equipment, mill flow-sheets, etc., but recently the spotlight has been focused on the cost of stoping and the cost of handling materials. Scrapers and scraper hoists have thus assumed greater importance. In order to make it possible for certain orebodies to be mined at a profit, it has been necessary to apply assembly-line practices to the streamlining of mining methods. All cycles of the mining operation must balance, and the sooner broken ore is removed from the working face, the sooner another round can be started. Since the introduction of scraper hoists in metal mines more than thirty years ago, much progress has been made in their design and application. Alert operators are now constantly watching for methods in which to apply scrapers. The saving of manpower in development work and the changing of mining methods that once employed manual handling of materials are increasing vital wartime tonnages. Essential ores from newly discovered orebodies are moving rapidly from stopes to reduction plants-because it is now possible to develop an orebody and place it in production with a minimum of manpower and development work. Today, speed is one of the prime essentials o mining. Everywhere, there is a concentrated effort to use experienced miners in breaking rock, in timbering, and in carrying out the various phases of mining that require many months of training. Much effort is being made to mechanize the working places because experienced men naturally prefer to work where the majority of materials are handled mechanically. In line with this policy, many new men are being taught the details of scraper work, because even green men can quickly become acquainted with scrapers and thereby release older heads to perform the more skilled phases of mining.

Jan 1, 1943

By H P. Tardif

This paper briefly describes some of the phenomena encountered when materials are submitted to extremely high pressures, such as those produced by the detonation of an explosive charge placed in contact with the material. It was found that extensive changes take place in the? microstructure of iron and steel. Diffusion-controlled processes, such as the transformation of lamellar pearlite, the recrystallization and grain growth of ferrite, and the homogenization of the pearlite-ferrite structure, can take place within micro-or milliseconds. Mechanical twins can propagate without deviation from ferrite to pearlite, thus indicating a proeutectoid ferrite-pearlite-ferrite orientation relationship. The propagation and interaction of intense stress waves in materials was demonstrated with the use of Armco iron. Finally, a comparison is made of the damage produced in metals by the formation of craters made by explosive shock and by hypervelocity impact. D DRING the last few years, exceptional development has taken place in the field of explosive metallurgy, i.e., the

Jan 1, 1964

By R. M. S. Häggblad

The article deals with stabilisation and regeneration of Ce02 and Ce02/Zr02 based Pt water gas shift catalysts, subject to high initial deactivation. The reaction gas species effect on the catalyst deactivation was investigated by H2-TPR. Activity measurements enabled the effect of different promoters, some added to the Ce02 based catalysts and some to the Ce02/Zr02 based Pt catalysts, to be investigated. The catalysts were also characterised by BET and CO-TPR. Deactivated catalysts activity was restored by using various regeneration methods. Of the two selected carriers the Ce02/Zr02 based Pt catalyst showed the highest resilience to deactivation. For the two different carriers, Ce02 and Ce02/Zr02, Wand Re were the best promoters when the catalyst was subject to deactivation. Experiments with Hr TPR indicate a fast initial change in the platinum oxides concentration and composition. The CO-TPR was used to make conclusions about the various regeneration effects of water and oxygen on the catalyst. Finally it is suggested that not one deactivation mechanism is possible and which mechanism that dominates is dependant on the catalyst and the reaction gas composition.

Jan 1, 2005

By S. Tavani, T. Rees

The current mining operations at Newmont Boddington Gold Mine (NBG) commenced in 2008, and commissioning of the processing plant started in the latter half of 2009. Metso Process Technology and Innovation were engaged to assist NBG with commissioning and project ramp-up through the implementation of a comprehensive “Mine-to-Mill” Process Integration and Optimisation project. This methodology entailed extensive data collection which included drill and blast audits, ore characterisation, comprehensive comminution circuit surveys and review of operational data to assess the limitations within the current mining and processing operations. The results of these investigations have been used to define the operating base line of both the mining and processing areas and identify improvement opportunities. The use of modelling and simulations, utilising actual production data, has allowed for multiple scenarios to be evaluated, minimising the requirement for actual trials and thereby minimising impact on the operation. Improvements implemented to date include: the introduction of routine rock strength measurement for inclusion in block models, modifications to blast design improving ROM fragmentation and downstream comminution process performance, and changes to improve performance of secondary crushing and grinding circuits. Close cooperation between the mine and plant personnel is playing a significant role in overcoming the challenges presented to this operation and further improvements are targeted for the second full year of process plant operation.

Jan 1, 2012

By D. Fodor

In Romania, there are significant lignite and brown coal reserves hosted by different regions of the country. The most important lignite bearing zone of the country situated in the North ? West part of Oltenia region and which covers a surface area of 2,500 km2 and host a total reserve of 3.0 billion tons of lignite, of which more than 95% can be exploited by open cast method. The paper deals with the existing geological and mining conditions of the zone , the distribution by mining basins and exploitation perimeters, the open cast working technologies and the economic outcomes obtained throughout the time. Years ago, for the improvement of the economic situation as a whole and in each unit, a large production reorganization, technology update and modernization process was started up. There are described the rehabilitation measures of the technological lines and modernization of the equipments of the production flow-sheet, measures developed at present, too and which will still continue in future. There are mentioned the equipments considered, the components under modernization and the economic outcomes obtained so far. At the end of the paper there are presented the future actions for the equipment modernization and perspectives of the lignite deposit exploitation to meet the national economy requirements of solid fuels.

Aug 1, 2013

By Robert Strachanm

The East Kootenay coal-field, situated close to the boundary between the provinces of Alberta and British Columbia, is composed of four small areas locally called the Crow's Nest Pass, the Upper Elk, the Flathead and Crown Mountain, and comprises an area of about 3 78 square miles. From eleven to twenty-five seams have been exposed of two feet and over in thickness, with a total thickness of about 200 feet of coal, and reckoning about one hundred feet to be workable, gives an estimate of coal available of about thirty-seven billion tons. The coal is a high-grade bituminous, occasionally tending towards anthracite, and the majority of the seams furnish a. very good quality of coking coal as well as an excellent steam coal. The coal-field is found in the mountain ranges in long narrow strips. The age of the fonnation and the thickness of the covering beds have had considerable influence on the character of the coal, and lateral pressure and disturbances in the process of mountain-building have wrought great changes. With such an abundance of coal, it has been a disappointment that the East Kootenay field has not figured larger industrially. So far only one portion of the coal-field has been utilized. This is the Crow's Nest, where, in 1898, the Crow's Nest Pass Coal Company commenced development. Access to the coal seams was easily obtained, the mountain creeks having eroded away the covering, and mines were driven into the coal seams. In that year about ten thousand tons of coal were produced from the mine at Coal Creek.

Jan 1, 1924