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By Yin Wang, Lin Li, Zhongwei Bi, Like Wei, Wen Li, Shaogang Li, Bin Zhang, Hongjie Li

Presently,Many long-wall fully-mechanized faces in shallow depth coal seams are below room and pillar goaf in Shendong mining area. When the working face is advanced out of concentrated coal pillar in upper room and pillar goaf, strong strata behaviors often cause support crushing accident. Aiming at a support crushing accident which happened in Shigetai coal mine of Shenhua group in Shendong mining area, this paper analyses the stress transfer process while mining out of concentrated coal pillar by numerical simulation software FLAC3D. According to the feature, simplifying the roof of upper room and pillar goaf as supporting-beam structure explains mechanism of large area collapse in room and pillar goaf roof. Based on the feature of supporting-beam structure, deep-hole blasting concentrated coal pillar technology is proposed to control the strong strata behaviors in Shigetai coal mine. The blasting control effect is confirmed through characteristics of strata behaviors, growth circumstance of ground crack and multi-point extensometer monitoring results. By using control technology, Shigetai coal mine has been successfully avoided support crushing accident.

Jan 1, 2015

By Douglas A. Sloan

"Recently, a number of major mining companies seemed unable to find a president from within the industry, and were searching outside the industry. From this, one could conclude that managers within the industry are either not being prepared or are not preparing themselves for presidential responsibility. Opinions were sought from a number of senior executives, to attempt to define the skills a prospective president should acquire and what actions a company could take or that a prospective president could take to acquire these skills.This paper contains summaries of the opinions obtained, along with the author's comments. The paper also describes the actions some companies are taking and the actions that an aspiring president can take to prepare himself for corporate management.IntroductionA manager is promoted up the management ladder when the manager's superiors believe that he is capable of handling a more senior position. Normally, the manager acquires this credibility by outstanding performance in his current management post, whether it be in a junior management (supervisory) or in a vice-presidential capacity.In most instances, the skills required for promotion can be acquired in the current position or, at worst, the abilities exhibited in a candidate's current role will convince his superiors that the necessary expertise for the more senior position can be acquired on-the-job. This is particularly the case when the new skills are felt to be an extrapolation of the old skills.However, in the case of appointment to presidential rank, there appears to be a need for new expertise which often is not acquired in normal management progression or, at least, boards of directors of some mining companies seem to believe this to be the case. The objective of this paper is to attempt to define the new skills that should be acquired by a manager who aspires to be the president, and to describe what actions might be taken by him to acquire them."

Jan 1, 1982

By A. J. Rigby

Computer generated, actual-scale furnace models have been imported into a rendering software application to provide for impressively realistic surface features and lighting. When these models are imported into a 3D engine framework, it is possible to create content-rich virtual environments allowing for complete interactivity and could provide for a powerful tool to conceptualize refractory lining designs. This technology has been applied to illustrate the optimized design concept of an anode-refining vessel, which can be expected to be completely relined in six days and to last for 4-5 years with minimal partial relining. This technology could easily be applied to other smelter furnace, converter and refining vessel designs.

Jan 1, 2007

By F. J. Macias, A. Bruland, F. E. Dahl

"Tunnelling by use of Tunnel Boring Machine (TBM) is gaining a greater presence as a suitable excavation method. Disc cutter consumption has a strong influence on performance and cost when using TBMs and the influence becomes even more relevant in hard rock. Furthermore, good predictions of TBM performance and cost facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory assessments are needed. A new abrasivity test method called Rolling Indentation Abrasion Test was developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than traditionally used methods by introducing wear by rolling contact on intact rock samples. INTRODUCTIONHigh investments are involved in the tunnelling industry, especially in Tunnel Boring Machines (TBMs) projects. Performance predictions and cost estimations are crucial for planning and risk management of TBM projects. Cutter consumption has a large influence in terms of time and cost, and an even greater effect in case of hard rock projects. Many factors are influencing the amount of cutters consumed in hard rock TBMs. Normal TBM operation results mainly in abrasive wear on the cutters and appropriate methods for abrasivity assessment are needed. Rock abrasiveness cannot be considered as an intrinsic property and the complete tribological system should be considered in addition to the geological properties of the rock.In the present paper, a new test method for abrasivity assessment in tunnel boring called Rolling Indentation Abrasion Test (RIAT) is presented. The traditionally used test methods for determination of rock abrasiveness uses sliding or impact contact in order to cause wear while the RIAT introduces rolling contact on intact rock samples. The ambition of the new test device is to have a reliable method to evaluate the cutter wear in hard rock tunnel boring by reproducing wear behaviour on rolling disc cutters in a more realistic way. It has been established by many authors that the abrasion of a cutter ring is proportional to its rolling distance (Rostami, 1997; Bruland, 1998). In the present work, the weight loss of a mini-cutter ring is measured subsequent to testing in order to evaluate wear in the rolling process and could hence be related to cutter ring wear. Indentation of the tools in the intact rock sample is considered as an indication of the surface hardness of the rock or the resistance to indentation by rolling."

Jan 1, 2015

By C. O. Staples, J. G. Morrow

The application of cationic flotation to the upgrading of magnetic concentrates was investigated in the laboratory by both batch and continuous test procedures. It was found that the collection of coarse gangue particles with amine, heretofore considered a serious obstacle to this particular application of cationic flotation, is greatly enhanced by a drastic reduction in what might otherwise be considered normal impeller speed. Gangue flotation is in-dependent of variations in the rate of aeration. The collector and Crother additions and the impeller speed which favour the formation of a matte froth yield optimum results.

Jan 1, 1966

By Dallas W. Davis

"Since May 1980, New Brunswick has called separate tenders for the right to explore and develop several potash prospects, as well as areas underlain by Alberta oil shale. These tender calls had in common the provision for a basic ad-valorem royalty, combined with sharing of cash flow after exceeding a 15-20% discontinued cash flow rate-of-return threshold. In the case of potash, the bidding variable was a share of cash flow, but for oil shale it was exploration expenditures committed, with the cash flow sharing to be negotiated at the time of application for a production lease. The Millstream potash occurrence, previously discovered by government drilling, received five bids (21.1% highest), the Dorchester ""grassroots area"" with four surmised drill targets apparently received no bids, and in the case of oil shale there were only two bids on the one block previously subjected to the most exploration.It is concluded that New Brunswick will not be successful in awarding the potash or oil shale rights in return for a comparable level of basic royalty and cash flow share as in the case of Millstream, unless it spends money in discovering prospects or sharing the exploration risk with companies. The approach is likely to work for oil shales only if current exploration proves the existence of much high-quality material or a definite trend of real increases in the price of oil is again established. Undoubtedly, it continues to be desirable to assure an on-going stable investment climate through award of potash and oil shale rights under terms which provide for a return that the public and future governments will consider fair. This could mean that some form or risk sharing with companies would be advisable."

Jan 1, 1983

By Michel Ruel, Ali Soltanzadeh, Benjamin Légaré

High fidelity commercial process simulation packages can be used at different stages of a greenfield project, from initial plant design to operator training in the later stages. However, there are several factors that make the software less attractive for small and medium size brownfield projects, such as the licensing cost and the fact-finding manpower required for model design and simulator maintenance. In this paper a different approach is described. The knowledge gathered from operating personnel was used to implement higher level models based on plant data, operating heuristics, and experience rather than detailed component-level models. The computing platform used was a low-cost, well-established, control system vendor-independent software. Throughout this paper we demonstrate the success of implementing this model-based approach using two industrial examples. The first example is a simulation of the carbon monoxide (CO) distribution system at a metallurgical complex. The purpose of this simulator was to test new control strategies and PLC programs prior to implementation. CO being a toxic combustible gas, validation of the suggested control system changes was necessary for plant safety. Simulation of specific operating conditions helped alleviate concerns and improved plant-wide acceptability of the new operating philosophy. The second example is a boiler simulator at a petrochemical plant. The operator training simulator (OTS) was designed as a platform for experienced operators to practice handling rare or abnormal conditions. A customized medium-fidelity model was developed for this targeted application where the cost of a full scale high-fidelity model could not be justified.

Jan 1, 2016

"Chairman - To start this discussion off, I wonder if Mr. Dave Livingstone or Mr. Jeffrey of Granisle Copper would give a description of the crushing plant at Granisle since it is somewhat different from the usual plant, W. N. Jeffrey - Granisle Copper The main difference between the Granisle crushing plant and many others is the Livingstone method of putting the screens under the crushers instead of above them. This method allows a more compact arrangement and eliminates the heavy superstructure required to take care of the screen vibration when the screens are mounted above the crushers. There is a small surge bin above the tertiary crusher which takes care of the variation in circulating loads.All three crushers are gyratory crushers. There is no grizzly ahead of the primary crusher but the fines are removed from the primary crusher discharge at the first screen and sent directly to the fine ore bins. E, Thornton - Sullivan GroupDo you have any coarse ore storage outside?w. N. Jeffrey - Yes, there is about 6000 tons live storage, We have very little trouble with freezing even though it is open storage.E. Thornton - Sullivan GroupDoes rain cause any problem?w. N. Jeffrey - It sometime creates a problem because the storage area is on a slope. It is mainly a problem of keeping the drainage ditches open.Question – What is the size of the primary gyratory crusher and how does it work on run of mine size materials, in other words, do you have a problem with oversize material and how do you handle the oversize rock?w. N. Jeffrey - The primary gyratory is a 42 x 65 with a nominal open side setting of 61'. We do at times get a run of oversize material. For anything too large for the crusher to handle, we use what is known as the Esco hook, which is a type of grapple used to remove oversize rocks.The disadvantage with this equipment is that the crane is too slow. I am sure there must be better arrangements than the one we have,"

Jan 1, 1971

By C. Ciriello

Six Sigma methodology, as applied within Xstrata (formerly Falconbridge and Noranda), involves a disciplined approach to managing projects, solving problems, improving performance, and leveraging information. The four (4) cornerstones of Six Sigma are the use of Philosophy (customer driven, desire to improve and discipline), Metrics (measurement systems), Methodology (scientific method and sequence of deliverables), and Tools (such as statistics, change management, and root cause analysis). This paper will outline the general steps of the Six Sigma methodology and demonstrate how each phase directly applies to a real plant metallurgical project aimed at reducing nickel losses of the rougher flotation circuit at Raglan. The main concepts of Six Sigma are described, along with the specific challenges, successes, and deliverables related to the project. It is also the authors' aim to demystify the basic Six Sigma principles.

Jan 1, 2007

By PAUL L. DEAN

Industrial mineral deposits are widespread in Newfoundland and Labrador and a variety of commodities are produced. The province has the only pyrophyllite mine in Canada and also produces asbestos, gypsum, silica, barite, limestone, gemstones, cement and other structural materials. Large reserves of these and other industrial minerals are known and several deposits are likely future producers. Most producers are wellestablished and have large tonnages of ore reserves.

Jan 1, 1984

By Chia-Chi Chiu, Meng-Chia Weng, Tsan-Hwei Huang

"This paper proposes a biconcave shape bond model for the distinct element method (DEM) to simulate cementation between two circular particles in geomaterials. Rather than an original parallel bond model between particles, the proposed model adopts the more realistic shape of cementation and considers the elastic response of cementation under external loading. The stress field and force-displacement relationship of the biconcave shape bond is based on Dvorkin’s theory, and three modifications are adopted: (1) A superposition method is applied to improve the correctness and symmetry of the stress field, and it also provides a method of addressing the status when both connected particles rotate; (2) To simplify the input parameters, the tangential movement is replaced by the normal deformation and rotation between particles; (3) To accelerate the calculations, variables are extracted in analytical procedures, which provide an efficient method for applying the bond model with only one matrix inversion. With these three modifications, the new biconcave shape bond model is created.To assess the validity of the proposed model, this study compared the elastic deformation in a single bond with an elastic analysis performed using the finite element method (FEM). After verification of the proposed model, a series of sensitivity analyses was performed to explore the effect of bond shape and the differences from the parallel bond model. For a single bond, the results showed that a biconcave model can represent the mechanical behavior of a biconcave shape bond and is effective with different bond shapes. The stress fields calculated by the biconcave model were more similar to the FEM results than those obtained using Dvorkin’s theory. The width and thickness of a bond have a considerable effect on its stiffness, and the variation of thickness decreases with the width of the bond. In addition, the required parameters can be acquired directly from real bond material rather than using the back analysis procedure for parameters.The biconcave model was further implemented in DEM software Particle Flow Code 2 Dimension to certify its applicability in geotechnical engineering. Using this model, a series of uniaxial compression test simulations was performed to analyze the macroelastic responses of specimens. The results showed that the macrotangential elastic modulus and Poisson’s ratio had a regular tendency, and they agreed with the stiffness variation in a microbond. This finding can assist in determining correlations between microand macroproperties and provides an innovative method for simulating the behavior of cemented granular material."

Jan 1, 2015

By Keith Eldridge, Robert Kelly

"Quality management has a/ways played an important role at the Iron Ore Company of Canada; particularly since the early eighties when the iron ore markets favoured buyers as opposed to sellers.Since thot time, IOC's quality system has evolved from basic quality control to the Deming philosophy and its 14 points, and on through various other phases to the ISO 9000 series.ISO 9002 Registration was' first requested by IDC's customers and development plans were prepared in 1988. At this time, Quality System Registration was unheard of in the mining sector and TDC found itself struggling with the concept. The 1U!Xt three years saw the company develop a Quality System to meet ISO 9002 in a two phased approach, setting new standards for the mining industry when registration was achieved in December 1991.The company now sees ISO Registration as the cornerstone of its future quality efforts. IOC's quality system has been integrated with several other initiatives such as loss control and functional training, both of which focus on training and management the workforce to do the job safely, the right way.This paper addresses the steps required to develop a quality system for the mining industry within the guidelines of the ISO 9000 Series and the subsequent integration of other quality related initiatives."

Jan 1, 1994

By M. Scobie, T. Atkinson

"This paper reviews the development of new designs in extensible and high angle conveyor systems. These aim to overcome the limitations of prior alternative concepts in design. The application of such systems in strip, terrace, open pit and mountain mining is reviewed. IntroductionTruck haulage costs have tended to escalate in recent years. This has been primarily due to operations generally moving to greater depths with associated increases in haul distances . Periods of high inflation rates have also been experienced for diesel fuel oil, tires and other petroleum based products. Recent international political events have tended to regenerate concerns over future oil supply and price stability. For such reasons, conveyor based transport is becoming increasingly attractive. Truck haulage maintains an inherent flexibility and improvements continue to be made in performance and capacity. Doubts must exist, however, over the extent to which further economies of scale may be made. Conversely, belt conveyor systems do not suffer this constraint and have the following advantages:• Electrical power is used and the specific energy consumption is at least half that required for truck haulage.• Operating costs and skilled labour requirements are lower.• Equipment has superior longevity and is ""inflation proof"" .• Access roads can be steeper and narrower in most mine environments, reducing construction and maintenance costs.• They are less prone to breakdown and bad weather delays .• In long haul, high capacity operations conveyors can save substantially on capital cost.• Environmental impact is improved with reduced noise level, dust and atmospheric pollution. Although conveyor systems are less flexible in operation than truck haulage and although a breakdown in any part of the system can immobilize the total system, mechanical availabilities of + 80% are constantly reported by large operators. There would appear in the past to have been some prejudice against conveyor systems in hard rock mines due to lack of experience. Apparent reservations would apply equally 10 underground coal mines, yet practically all of these mines (and some underground hard rock mines) find conveyor systems more economical than other transport systems."

Jan 1, 1991

By L. Dorador

"In block caving projects, the rock mass fragmentation process plays a controlling role in the design and success of the operation. Poorly understood, however, is the secondary fragmentation that occurs as blocks of caved ore move through the draw column and interact with one another. The initial size of these blocks can be considerable, as can their strength and stiffness as the presence of non-persistent joints and veining will be variable. Intuitively, more planes of weakness within the blocks should facilitate early fragmentation, but this assumption could depend on additional factors such as contact type between adjacent blocks and loads imposed through varying heights of the draw column. This paper reports the findings from a laboratory investigation examining the role of block strength and planes of weakness on secondary fragmentation. Testing was carried out on small-scale concrete cubes of uniform size, with and without embedded planes of weakness. The results obtained demonstrate the significance of veining and other planes of weakness on secondary fragmentation under one-dimensional compression, and allow for the development and constraint of empirical guidelines.INTRODUCTIONThe fragmentation process during block caving involves the initial (primary) fragmentation of rock in the cave back through stress-induced fracturing, release and fall of individual blocks onto the broken ore muck pile. This is followed by secondary fragmentation involving splitting and rounding of blocks as they move downwards through the draw column towards the draw point. The degree of secondary fragmentation achieved involves many variables related to the mechanical properties of the rock blocks as well as different operational factors. With respect to the block properties, the presence of planes of weakness in the form of veining and non-persistent joints is a topic of special interest given the significant influence it potentially has on the overall fragmentation process. However, the inherent heterogeneity and variable size of individual blocks generated from the cave back makes it difficult to develop any empirical relationships relating secondary fragmentation to compressive loading based on insitu observations and mine data. More preferable would be to keep constant block parameters, such as shape (aspect ratio and angularity) and size, through controlled laboratory testing. This work presents an efficient technique to fabricate concrete cubes in order to keep constant different block properties. These are then tested under one-dimensional compressive loading. The objective of these tests is to emulate a tight packing condition of single blocks such as that which would occur when the air gap between the cave back and broken ore in the draw column is small. When the air gap is small, detached blocks are unable to fall and rotate but instead maintain a very tidy arrangement with minimal voids left between adjacent blocks."

Jan 1, 2015

By M. Côté, H. Pépin, Y. Richer, C. Gingras

Rolls-Royce Canada has been nominated as a Rolls-Royce Center of Excellence for repair of fan blades in 2003. One of the challenges of the Rolls-Royce Canada Component Repair Center of Excellence team is to reduce cost and time of inspection while ensuring trace ability and quality of the inspection performed on the fan blades. In the context of the dimensional control process optimization, and following the positive conclusions of initial trials carried out in 2003, the technical authorities at RRC have selected the SPG data 3D(TM) technology as a development base for dimensional control programs. The main goal of this development initiative is to develop and support an inspection system to perform the dimensional control and inspection of different components at the Montreal Fan Blade Repair Center of Excellence. The final objective of the program is to build a server platform capable to support different inspection sites within the Montreal facility for the future. This paper presents the certification process of the technology according to the VDI-VDE 2633 certification standards and some results of the fan blade inspection program of the BR 710, BR 715 and TAY according to the JES 195 engineering standards specification.

Jan 1, 2006

By C Kumar

Scaffolds are temporary structures built to facilitate construction activities on site. A considerable amount of resources are allocated to scaffolding on industrial projects. Variability in geometrical features and space accessibility of structures on industrial projects, in addition to involvement of different trades that share the use of scaffolds, requires an extensive understanding of scaffolding requirements. Hence, it?s important to plan and estimate scaffolding man-hour requirements for the different construction areas on an industrial site. Contributing factors involved in such estimates include the list of trades that work in a construction area, trade working hours, volume of work, geometry of equipment erected, etc. A simulation template for predicting scaffold erection man-hour values for individual construction areas in an industrial project was developed in Simphony 4.0. The template is based on mapping the geometry of equipment and other factors to man-hours of scaffold work. The template facilitates the use of distributions as inputs and produces a range estimate of scaffold man-hours. The mapping is based on a linear regression model derived from existing project data from PCL Industrial Management Inc. The template is being further developed to incorporate the ability to predict scaffold erection schedule and material requirements based on construction work areas or equipment lists of an industrial construction project.

Aug 1, 2013

By Paul A. Glapa

Quality is much more than providing a product that functions properly. True quality is a way of thinking, a way of doing business, and, ultimately, a way of satisfying a customer?s long-term needs. A true commitment to quality requires a top-down management commitment, with a willingness to change what needs to be changed and to expand upon ?best practices? that are already done well. Is there a cost to creating and maintaining a quality program? Of course there is, but the cost of not having a focused program is much greater. We have come to regard quality as an investment that pays dividends to both the supplier and customer. The lack of quality costs everyone and the customer pays the ultimate penalty. With modern, highly engineered surface mining equipment the end user calculates cost in terms of lost production (revenue), not simply the cost of the part. Bucyrus International, Inc. is a company that has listened to its customers and has dedicated itself to implementing an advanced quality program. The ultimate goal being the creation of a high quality product with extended reliability for the customer. The result is reflected in Bucyrus? current product offerings and highlighted by the new 495HF electric rope shovels at Albian Sands mine.

May 1, 2003

By René G. del Villar, Jules Thibault, René del Villar

"Some key control variables of industrial processes, associated with product quality, often cannot be measured directly or frequently enough to establish adequate control. In such cases, it is possible to use available measurements to provide a prediction for these process variables and use them in a control strategy, thereby giving rise to what is now commonly called a softsensor.In some industrial grinding circuits, the on-line particle size analyzer is shared between various sampling points. Therefore, for a given location, the actual measurement is only available every 10 to 20 minutes, a delay which is unacceptable for automatic control purposes. To alleviate this problem, a softsensor based on an artificial neural network has been investigated. First, the structure of the neural network and different schemes for the training process are analyzed. Then, the performance of the neural network softsensor is compared with other inferential methods such as ARMA models and Kalman filters.IntroductionGRAHM, French acronym of the Research Group on Computer Applications in the Mineral Industry at Laval University, began in 1990 a research project on Knowledge Based Automatic Control (KBAC). This project, sponsored by a consortium of eight mining companies and the federal and provincial governments, seeked to screen advanced (knowledge-based) methods for data processing (filtering, mass balancing, etc) and automatic control (model-based) for their use in the mineral processing operations and the transfer of the project results to the sponsor companies.In parallel to more academic research work, a number of case-studies have been undertaken with the cooperation of partner companies. Among such works, a very successful one has been the design and installation of a new control strategy for one of the Kidd Creek (Falconbridge Ltd.) grinding circuits. This project was related to the evaluation of a number of control strategies and the implementation of one of them, as selected by the plant management, in the concentrator.A total of sixteen control schemes were evaluated on one of the dynamic phenomenological simulators developed at GRAHM, a trademark of this research group [ l]. The calibration of the simulator models was done based on industrial data gathered by GRAHM and Kidd Creek personnel. Then, the simulator was used to test the performance of various PID-based control schemes, designed to achieve the control objectives set by the Kidd Creek personnel. The best scheme proposed called for controlling the cyclone overflow particle size by manipulating the water addition rate to the cyclone feed box and the circulating load by manipulating the circuit ore feed. The particle size analyzer (PSI-200) available for monitoring the product size, was unfortunately shared (multiplexed) among various streams of the plant, which meant a 14 min delay between two consecutive readings for any particular stream. This induced the plant personnel to choose an alternative control strategy, one which controlled the cyclone feed density instead of the cyclone overflow particle size."

Jan 1, 1996

By J. Borlee, F. Sorrentino, A. Fleischanderl, M. Gimenez, W. Gebert, U. Gennari

Large quantities of solid by-products are generated by the steel industry and other important activity sectors in Europe (power plants, car dismantling companies, urban incinerators) with no or very limited potential for direct recovery. In the frame of a multi¬national project supported by the European Union, a consortium has been created to develop a treatment process able to turn these by-products into valuable metallic and mineral products. VAI has been responsible for the design, erection and start-up of the pilot plant for the new metallurgical process and for the execution of the test campaigns, with the targets defined together with the partners. Up to now, 9 campaigns comprising 60 heats have been performed successfully. By-products from C-Steel and stainless steel plants, as well as fly ash and auto shredder residues, have been used and defined products such as hydraulic binders for cement, metallurgical powders for De-S practice and recycled metal phase have been produced. The mineral products were positively assessed under industrial conditions. Results from cement tests and secondary metallurgy are reported, as well as a detailed characterization. The economic value of the products, credits from avoiding dumping and significant savings on CO2 emissions make the new process economically very attractive.

Jan 1, 2004

By T. Velea

The most widespread methods for producing metallic copper are smelting of copper sulphide concentrates (which generates various types of polluting substances) and the hydrometallurgical route which consists of leaching in sulphate and chloride media (usually employing high temperature, high-pressure and special equipments). This paper presents a process, called VEPE, which consists of oxidizing copper sulphide concentrates in weak alkaline media (Na2C03 orland NaOH solutions), under low pressure and with air sparging. The oxidized concentrate contains less than 0.4% S. Copper is recovered from the oxidized concentrate by the standard leaching-solvent extraction-electrowinning route, with a total efficiency of 98% extraction. The proposed technology could represent a good opportunity to recover copper from sulphide concentrates in a clean, simple and profitable way.

Jan 1, 2007