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By Chris D. Veldhoen

If you ask most diamond drillers if they have ever encountered methane gas, the answer would probably be yes. This paper explores a serious methane gas explosion that the author experienced while diamond drilling at a northerly Ontario mine. It is hoped that by documenting this event, people may be alerted to the hidden danger posed by confined methane in underground workings. Methane gas tends to be a problem the deeper you get in any Canadian gold mine. Common procedure when encountering methane is to take readings at the collar of the hole and at different lengths from the source. Monitoring continues until the readings drop below 0.25 ppm. Methane is a tasteless odorless gas that is usually locked up in the seams of the rock or is a product of decaying organic material. Occasionally, the gas is released abruptly over a short period of time. Sometimes the gas can continue to vent for months or even years. In small concentrations, methane is relatively safe. In concentrations under 0.25 ppm methane gas is considered safe to work around. Concentrations over 0.25 ppm can become dangerous. During the summer of 2001, Chris Veldhoen was drilling at a gold mine in Ontario. There were three electric hydraulic diamond drills on the 39 meter level, approximately 5200 feet deep. Two Longyear LM 55 drills were about 40 feet apart and another LM 75 was about 2000 feet away. The two LM 55?s were set up to drill holes no deeper than 350 meters. All three drills had been set up on the same spot for more than a month. None of the three drills had ever encountered methane gas in the entire time they had been drilling on the level. On the day shift of July 13 2001, the driller on Chris? cross shift hit a small pocket of gas. He tested the hole and got a reading above 0.25 ppm. He proceeded to rope off the area with a ?DO NOT ENTER - METHANE GAS? sign and a rope denying access beyond the sign. On Saturday, July 14, Chris was instructed to install a Margo plug in the hole that was emitting methane gas. Methane is usually odorless, but occasionally when encountered underground, is accompanied by a rotten egg smell. As he walked to the drill, he could not smell methane gas. He proceeded to test the hole and got a reading of 0.22 ppm methane. This number was in the acceptable range for drilling, but he plugged the hole anyway.

May 1, 2004

By M. Amsden

"Since the computer program is far from complete this must be only a brief progress report on the computerization of flotation metallurgy at the Ecstall concentrator at Timmins.Ecstall is currently treating about 10,000 tons per day of two different ore types. One is a low sulphide copper-zinc ore, the other is a high sulphide lead-zinc-silver ore. The concentrator is divided into three individual grinding and flotation circuits. In effect there are three mills under one roof. Normally there are two circuits on copper-zinc ore and oneone lead-zinc-silver ore. At this point in time one of the copper-zinc circuits is under computerized metallurgy control.The first step in this control is the use of an ARL on-stream x-ray analyzer, coupled with a Honeywell 21 computer which types out assays and recoveries for each individual circuit. Our approach to a computer program was to keep it simple. The program was written to coincide as closely as possible to what an operator would do in the performance of his duties based on the in-formation he was getting from the x-ray analyser read-out. Initially, computer control was put on just the copper circuit of the ""A"" Division, controlling the collector addition at three points in the circuit; primary, secondary, and scavengers. The control was based on recoveries and the grade of the copper concentrate. Targets like 95% recovery and 24% copper concentrate grades that it was felt the circuit could achieve were set to start with. It quickly became apparent that this alone was not enough because if on a certain ore the best recovery that could be made was only 94.9% the computer kept calling for more reagents until the circuit was completely out of control. On another ore it might have been quite possible to get 96% recovery but when the set point of 95% was reached the computer stopped trying for any more. To overcome this problem a very simple optimum seeking program was devised by one of the Ecstall staff and it has worked very satisfactorily since being put into use in July 1970.In the copper float only the two collectors R-208 and the xanthate R-317 are under computer control. The addition of frother and depressant is left to the operator. The flotation cells have automatic level controls which can be adjusted by the operator. pH is controlled automatically through a lime loop-sensor arrangement."

Jan 1, 1971

By Ron Tessier, Claude Bazin, Robert Grant, Mike Cooper

"Grinding simulators are now widely available to assist in the optimization of industrial circuits. They provide circuit operating conditions or flowsheet designs that yield a given product size distribution. However, they do not provide information of the impact of a change of product size distribution on the subsequent flotation or leaching stages. This paper presents a method to predict grade and recovery indices for a flotation plant as a function of the flotation feed size distribution. The application of the method to various size distributions allows the determination of the optimal fineness of grind. A case study for a CuPb rougher circuit of a New Brunswick complex sulphide processing plant is presented to illustrate the method.IntroductionIs the grinding circuit product fineness optimum for the subsequent separation steps? This is a question that is certainly very difficult, but critical, to answer. Laboratory and pilot plant testworks can provide clues as to whether grind should be finer or coarser. For a full scale operation there is no other way than trying to change the setup of the grinding circuit and verify the effect on flotation. True effects can, however, be masked by the numerous and unexpected disturbances inherent to grinding and flotation circuit operations. A good preliminary investigation requires a noise free environment to elaborate possible solutions for the question.Plant simulators provide this noise free environment. However, despite grinding and flotation simulators having evolved significantly for the last 20 years, very little is available on the integration of both simulators to analyze the effect of fineness of grind on metallurgical performances. For instance, a grinding circuit simulator may help to find the tuning of a grinding circuit that will yield the desired fineness of grind, but does not inform on the effect the new product size distribution will have on the separation stages. Linking grinding and flotation would require a flotation plant simulator with the rate and infinite recovery parameters for each mineral in each size interval considered. This approach is seldom used because of the tedious work required to estimate the model parameters. Recently Leroux(1992) proposed a method to predict mineral liberation from grinding ore of known mineralogical texture. Although the method is still at its infancy it may provide, when combined with a reagent conditioning model (e.g Niemi et al., 1982; Bazin et al., 1988), a way to simulate flotation without the need of entering the numerous parameters of a flotation model."

Jan 1, 1994

By Doris Stüben, Geoffrey P. Glasby, Akira Usui, Jörg-Detlef Eckhardt, Bruce W. Mountain, Zsolt Berner

"Abstract - Twenty-seven marine Mn and Fe deposits chosen for their diverse origins have been analyzed for five platinum-group elements (PGE). The PGE display their highest concentrations in hydrogenous Mn crusts and nodules, lesser concentrations in diagenetic nodules and two to three orders of magnitude lower concentrations in hydrothermal Mn and Fe crusts. This difference of behavior reflects the well-known fractionation of Mn and Fe from the other transition elements, rare earth elements (REE) and PGE in hydrothermal Mn and Fe crusts. Pt, Ru, Rh, and Ir show a close geochemical coherence in these deposits and are differentiated from Pd which shows a negative anomaly with respect to the other PGE in hydrogenous and diagenetic Mn deposits. Pd is less depleted than the other PGE and the Pd anomaly much less pronounced in the hydrothermal Mn and Fe crusts relative to the hydrogenous and diagenetic Mn deposits.Stability field diagrams show no evidence for the oxidation of Pt to the tetravalent state in seawater as suggested by some authors. Rather, Pt appears to be present in seawater as Pt(OH)2 0. Adsorption of Pt(OH)2 0 onto the surface of Mn and Fe oxyhydroxide minerals may explain the enrichment of Pt in marine Mn deposits. However, Pt metal is the thermodynamically stable solid phase of Pt under seawater conditions and reduction of Pt(OH)2 0 to Pt metal, particularly in the vicinity of the oxygen minimum zone, is possible, although the high Ce/La ratios of the Co-rich Mn crusts do not support this hypothesis. Pt, Ru, Rh, and Ir display their maximum concentrations in the Corich Mn crusts. This may reflect, among other things, the low growth rates of these deposits. The stability field diagram of Pd shows that Pd is undersaturated in seawater and occurs in seawater dominantly as PdCl4 2- and anionic mixed-hydroxide-chloride complexes. This would explain the anomalous position of Pd among the PGE with respect to its uptake into marine Mn deposits. A study of inter-element associations indicates that the incorporation of the PGE from meteoritic dust plays only a minor role in the uptake of these elements into marine Mn deposits. The PGE remain the most poorly studied group of elements in marine Mn deposits. The data presented here emphasize the need for the establishment of a more comprehensive database of the PGE in marine Mn deposits in order to understand more fully their uptake into marine Mn deposits and their pathways through the oceans."

Jan 1, 1999

By A. Kozlowski

We present research on cable fault location methods for mines where coal dust and methane explosions are a frequent potential hazard. The methodology and devices for low- and medium voltage cables fault location are well known and applied in classical power distribution networks. They are based on solutions for underground mines with a high risk of explosion. The lack of a safe solution for the location of a fault has contributed to the initiation of a research project by a group of Polish companies. The consortium consists of research institutes (Institute of Innovative Technologies EMAG, Tele and Radio Research Institute, Central Mining Institute GIG-KD ?Barbara?), Silesian University of Technology and a private entrepreneur MARTECH PLUS. Fast and exact determination of fault location is one of the important factors for minimizing power outage time. The lack of technical solutions to obtain measurements in a secure way leads to the use of the methods connected with a high risk of explosion. For example, the application of high energy can lead to arc discharge where there is a fault in insulation, creating the risk of an explosion. Measurements of methane concentration along the analyzed section of the cable reduce the risk; however the shock wave generated by the electric arc may raise coal dust and make an explosive mixture, which is an object of ignition. Low energy methods, like those based on reflection waves, have low sensitivity for high- and medium-resistance faults. This technique has difficulties in joints, which create false echoes. The fundamental problem is to determine the topology of the network using a reflectogram and find anomalies of a different nature ? not only open and short circuit. Included in the scope of the project is an analysis of Polish legal regulations related to fault location and operational work for low- and medium-voltage networks. Two of the methods used on the surface were selected as feasible to implement under explosion hazard conditions. In the process of development of the fault location methodology, installation features characteristic of underground mines were used, namely access to the whole length of a cable. This is the attribute that provides an opportunity to do measurements that are usually not possible for typical surface power nets. To carry out laboratory tests, a dedicated measuring stand with various types of cables was built. The authors describe the principle of operation of the fault locator and the results of the laboratory tests carried out on the cables with built-in damage (prepared for tests). Results of the work will be the basis for the next stage of the project associated with operational analyses of the prototype.

Aug 1, 2013

By J. Suarez

The innovation initiatives for world-class mines today and in the future focus on automation and robotics in equipment and machinery. These innovations have benefited from the development of advanced tools in global positioning, the Internet, the capabilities of data storage, transmission and handling, and intelligent systems. Forward-thinking companies have been investing in automated trains and trucks, selfdrilling rigs, intelligent flotation systems, etc. Considering that the emphasis has been mostly laid on improving the performance and reliability of the equipment and machinery, it is not surprising that the visibility was geared toward mechanical, electrical, process, and metallurgical engineering. One of the critical disciplines, mining engineering, has had less shine from the spotlight of automation and robotics. Mining engineering is concerned with the design, the operation, the management, and the reclamation of mines and mining facilities. In essence, it does benefit from the advantages of automation and robotics in equipment and machinery. However, being ?left out? in the innovation process may impede the core capabilities of this engineering discipline, which would create a two-tier knowledge and technology system in mines. For example, shovels in an open pit may be equipped with technology that can send real-time data of actual payload, number of buckets, mechanical status, etc. But, are mining engineers aware of the possibility to incorporate the data into their planning tools in order to have updated forecasts and accurate information? And if they are, are they equipped with the tools to reap the rewards of those technologies? And if so, is the personnel trained to use the tools efficiently? This paper is a contribution to the discussion on the technological advances in mining engineering. For the authors, the roadmap to the future requires a smart integration of technological advances in hardware and software so that mining engineers are not only aware of the possibilities, but also trained and capable of using the available tools. Essentially, this paper believes that automation and robotics in equipment alone will be undervalued and underutilized if the owners and drivers of the mining systems (i.e. the mining engineers) do not possess the tools and training to integrate the technological advances into the functions of mining engineering. The intent of the paper is to analyze the available technologies for the core mining engineering functions of design, planning, scheduling and optimization. The analysis will lead to discussions and suggested solutions on integrative technology solutions that would create optimum value for the mining processes and equipment technologies.

Aug 1, 2013

By R. M. Oliver

THE Falconbridge property is almost completely covered with over-burden to a depth varying from 60 to over 200 feet. This overburden consists of grave], sand, and boulder, with bands of very fine silt, and there is usually a layer of water-bearing quicksand adjoining the r:ock surface. In previous shafts sunk at Falconbridge, this water-bearing quicksand had given considerable trouble, and further difficulties were expected in sinking No. 5 shaft, due to its greater size. The method described in this paper is the one adopted in sinking this shaft, after the matter had been carefully considered. No. 5 shaft is located 2,400 feet east of the old main No. l shaft, and is sunk in norite in the hanging-wall of the ore-body, which is, however, ? practically vertical to the deepest known intersection. The greatest depths of overburden prevail on the south side, or footwall, of the ore-body, and this, together.. with the fact that the footwall is wet and more badly fractured, swayed the final decision to sink in the hanging-wall. After the shaft site had been chosen and cleared, a diamond drill was set up a few feet away and a hole bored to a depth of 405 feet to test the over-burden and character of the norite bedrock. The depth of overbudren indicated by the hole was Ill feet, with the last 10 feet water-bearing. The norite was rusted and broken up for only a few feet below bedrock. A steel sinking shield (Figure l) was assembled at the shaft location, and consisted of 5/8-inch plate, 5 feet deep, built around a frame of 6 inch by 6 inch angle-iron, and braced at the corners with the same material. Twelve-inch I-beams held the shield as rigid as possible. In order to reduce binding against pebbles to a minimum, the shield was constructed with a 1-inch batter on all sides.

Jan 1, 1938

By Y. Feng

Perovskite structured oxide 15% Y-doped BaCeO3 (BCY15) has been evaluated for use as proton conducting electrolyte in SOFC with propane as the fuel and Pt as both electrodes. Under the fuel cell conditions, BCY15 exhibited high proton conductivity and good cell performances. Propylene was detected as product at the anode outlet, and the product distribution suggests that propane dehydrogenation underwent competition with cracking to lighter hydrocarbons. Stability during cell performance tests showed that there was no obvious degradation for BCY15 electrolyte during operation of C3H8-O2 fuel cell.

Jan 1, 2005

By R. Heikkilä

The utilization of Building Information Modeling (BIM) and model based 3-D control of work machines have increased a lot in new road construction in Finland as well as in other Nordic Countries. Up today, much less attention has been paid into the development of maintenance and rehabilitation processes. As a part of a large research and development program RYM PRE Infra FIN BIM in Finland, a focused research project of the BIM with experiments in total five (5) pilot projects has been performed. A main idea of the new BIM based process has been to utilize mobile laser scanning method for initial data acquirement, the use of novel 3-D analyze and modelling methods for point cloud processing, the use of new type optimization method for the planning of geometric and structural improvements needed for the existing uneven road surfaces, and further, through the creation of 3-D machine control models apply the newest 3- D machine control systems for continuous 3-D control of practical construction work using milling machine and asphalt paver. Finally, an evaluation is made between the new process model and the traditional way of working.

Aug 1, 2013

By D. B. Stewart

This paper reports on an investigation undertaken to determine the exhaust gas temperatures of operating underground mining equipment. The effectiveness of platinum catalytic purifiers is discussed. From exhaust temperatures, it is concluded that LHD engines are highly loaded, haulage truck engines are moderately loaded and utility vehicle engines are lightly loaded.

Jan 1, 1979

By W. N. Hamilton

Industrial minerals are plentiful in Alberta. Although exi ting in variety and in quantity, they constitute a minor segment of the province's mineral industry, which is based on oil and gas. In 1983 Alberta led all the other provinces in value of mineral production with a total of $22,2 18 million, 62 per cent of the total for Canada. Of Alberta's total, $22 million or about 3 per cent came from the indu trial minerals. Nearly two-third of this production is accounted for by sulphur, which is actually a by-product of the oil and ga industry. Alberta ranked third among the province in industrial minerals production for 1983, with about 20 per cent of the national total.

Jan 1, 1984

By F. Rashchi, N. Naseri Joda

Recycling of electronic wastes is an important subject both from an environmental point of view and also the recovery of valuable materials. In this research, PC board scraps were leached to recover Cu, Ag, Au and Pd. Due to the high cost of the shredding process and to avoid secondary pollution from odors and dusts, board scraps were cut into 5X5 cm2 pieces. To determine the most effective leachant, aqua regia, nitric acid, hydrochloric acid, ammonium persulfate and potassium persulfate were tested. The effect of the leaching parameters, the leachant concentration, temperature, leaching time and liquid to solid ratio were studied and optimized using response surface methodology.

Jan 1, 2011

By S. Abu-Samra

By virtue of its complex nature, the construction industry comprises a wide spectrum of interrelated variables and factors. This multifaceted character of the construction industry puts the use of engineering modeling tools and techniques on top of project management necessities. This research introduces a macro-level earthmoving management system using Genetic Algorithms (GAs) to reach the optimum allocation of earthmoving equipment. The Earthmoving Equipment Management System (EEMS) functions through four integrated modules: (1) A Central Database containing information about projects and available equipment; (2) An Equipment per Segment Selection module that calculates the cut and fill quantities, plots the Mass Haul Diagrams, and selects the equipment types to be used for each segment; (3) An Equipment Pool module which determines the production and cost for each available equipment, based upon the project site conditions; and (4) An Optimization Engine equipped with a GA optimization solver. This engine formulates the optimum earthmoving cost for all projects, by changing the number of allocated equipment. The Optimization Engine takes into account the number of available equipment and calculates the weekly equipment allocation. The EEMS model was implemented on an earthmoving company conducting five different projects on hand. The model proved to be an effective tool in providing decision makers with optimum equipment utilization on a multi-project scale to minimize the earthmoving cost. The results were then compared with the company?s existing micro-level management system, demonstrating better performance on the level of savings, amounting to 13% of total earthmoving cost.

Aug 1, 2013

By Tatsuya Oki

Tantalum capacitors can be found mounted on printed circuit boards of domestic appliances such as personal computers. These capacitors contain a considerable quantity of expensive metal tantalum and can be detached and liberated from printed circuit boards by impact breakers. In this study, the size and density distribution of the liberated electronic devices were investigated. Then, tantalum capacitors were recovered from other electronic devices using size separation and pneumatic gravity concentration methods. More than 70% of Newton's separation efficiency was obtained for tantalum capacitors. High Newton's separation efficiency could be also obtained for other types of electronic devices such as chip resistors.

Jan 1, 2011

By Ann Lamontagne

Le parc à résidus de l?ancienne mine Dunraine contient des résidus générateurs de drainage minier acide. Le concept proposé pour la restauration du site est d?utiliser le fort potentiel alcalin des boues rouges, résidus d?aluminerie, afin de neutraliser les résidus miniers. En appliquant une certaine quantité de boues rouges à la surface du parc, on provoquera une neutralisation de l?acidité. De plus, les alcalis contenus dans les boues rouges vont provoquer la précipitation de minéraux stables (sulfates tel la jarosite). La précipitation de ces minéraux provoquera la formation d?une couche indurée qui rendra difficile la circulation de l?oxygène et de l?eau. Bien que ce concept ait été vérifié en laboratoire, ce sont là des hypothèses qui restent à vérifier dans des conditions réelles d?exposition. Les principales questions soulevées par l?utilisation des boues rouges, mis à part le contexte géochimique, est le contexte technico-économique. En effet, le transport de quantité importante d?un matériel argileux humide présente un défi économique important. Outre le défi économique, la manipulation et l?épandage de ce produit sur des parcs à résidus constituent également un défi important. Cet article présente les conclusions d?une étude technique sur le transport, la manutention et l?épandage de boues rouges sur un parc à résidus situés en Abitibi : le site de Dunraine.

Nov 1, 2002

SOFCs with thin electrolyte of two types: SDC (15um) single-layer and YSZ (5um) + SDC (15um) bi-layer were fabricated by screen printing and co-firing on Ni¬YSZ cermet substrates. Using in-situ sintered Sm0.5Sr0.5CoO3 cathode the SDC-cell shows high performance at low temperature, 1180mW/cm2 peak power density around 650°C, while the YSZ+SDC bi-layer cell generates about 340mW/cm2 at 650°C, and good performance at 700-800°C with almost theoretical OCV value. Many Zr-content micro-islands were found on the SDC electrolyte surface. The influence of co-firing temperature and thin film preparation methods on the Zr-islands' appearance was investigated.

Jan 1, 2005

By Laura Prati

Gold-on-carbon catalysts resulted very active and selective in liquid phase oxidation [1, 2, 3] and during past studies we established that activity is ruled by two factors: particle dimension and gold exposure on the carbon surface [4]. These two parameters are also connected to the nature of activated carbon where the chemical nature of the surface oxygenated groups probably plays an important role [5]. Our studies, focused on the design of an active gold-on-carbon catalyst for liquid phase application, were aimed, operating a fine tuning of all the parameters involved in determining activity, to optimize gold-on-carbon preparation, keeping in mind that gold particle activity increases with decreasing particle size and increasing gold exposure. Gold sol immobilisation represents a versatile methodology in preparing gold catalysts [6]: throughout this work we used as sol stabilizing agent, the N-dodecil-N,N-dimethyl-3-amino-1-propan sulphonate (SB), that provides both sterical and electrostatic stabilisation, a condition we already demonstrated necessary to preserve particle dimension when carbon is used as the support [6]. We generated different gold sols by varying the relative amount of reagents (HAuCl4, SB, NaBH4), the type of alkali and the temperature of the gold precursor reduction. Moreover, as we had recently evidenced that there is also a carbon effect [5], we employed only one active carbon to immobilize the sols.

Oct 1, 2003

By E. Michelotti, M. Cardu

This paper presents the results of a new method that has been tested to recover metallic cobalt lost by diamond beads from rock cuttings. When dimension stones are cut using diamond wire saws, the beads become worn and, before the end of their cycle life, lose a certain amount of material; this material is prevalently made up of sintered metal and diamonds. The material is then washed away, together with rock debris, in a dilute pulp. In effect, this process involves the dispersion of economically valuable, but potentially polluting, materials (such as cobalt) that are used to confer indispensable technological features to the beads. This current research aims to develop a waste-processing pilot plant (High-gradient Magnetic Separator or HGMS) to recover metallic components from the pulp by means of a suitable separation. The research\u2019s purposes are two-fold: a. to remove the polluting components from the rock debris before their disposal and b. to start a recycling process of the valuable metals.

Jan 1, 2010

By Qing-hua Tian, Li-then Cheng, Xue-yi Guo

In order to recycle valuable metals from silver separated residue, a novel method using alkaline smelting at low temperature was proposed. The main factors affecting the main metal recovery such as the smelting temperature, smelting time, liquid-to-solid ratio and alkali addition were investigated comprehensively. The behavior of the main metal elements, such as Pb, Sn, Sb and Bi in silver separated residue was also discussed. The results indicated that amphoteric metals such as Pb and Sn can be smelted into the melt, while other metal elements, such as Sb and Bi were left in the residue.

Jan 1, 2011

By Patricia J. Dillon

Established in 1997, Prospectors and Developers Association of Canada Mining Matters (PDACMM) is a registered charitable organization dedicated to providing Earth Science education to grade school students. Through the development and distribution of educational programs and materials, PDACMM informs students of Canada?s geology and mineral resources as well as promoting awareness of the importance of rocks, minerals, metals and the mining industry. PDACMM also co-ordinates with other charitable organizations and government agencies to provide support or to work in tandem with them and reach as many young people as possible. Although PDACMM became a charitable organization in 1997, it actually has its? roots in 1994 when the Grade 7 program Mining Matters/Une Mine de Renseignments was developed to help teachers bring geology and mining into the classroom. Over 2100 of these resource kits were distributed to teachers across Ontario during the period 1995 to 1998. This unit won national recognition when it received the prestigious Partnership Focus award from the Conference Board of Canada for ?promoting science literacy for the world of work?. Due to the phenomenal success of these kits, a Grade 4 kit entitled Deeper and Deeper/Aller au Fond Des Choses was developed in 1998 in response to the opportunity provided by the new Ontario curriculum released at that time. Over 2600 of these kits were distributed throughout Ontario and there is a substantial waiting list of teachers hoping PDACMM will be able to raise enough money for another print run.

May 1, 2002