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By Gareth Barnes

Traditional approach to improvement is driven by good ideas from good people, but whilst the business case may sound good, when the project is complete, we often have not delivered on expectations.  Why not? The best way to successfully predict the outcomes of an improvement effort in a complex process is through using statistical modelling, which considers the impact of uncertainty within interacting processes.  Applying Theory of Constraints in a model helps leaders to quickly determine: Where the constraining process(es) is/are Where improvements will add the most value How much improvement should be targeted - before the next constraint takes over The confidence level of achieving a given target, which gives us a clear pathway to improvement. This paper presents an analysis of statistical modelling applications at Vale’s Manitoba Operations to achieve the 2025 targets. Using statistical modelling of the Business Structure, the team identified a series of process improvements through a Theory of Constraints Analysis. Value Stream Maps (VSMs) were used to define the required data, apply statistical modelling, and conduct training sessions enabling the Manitoba team to identify the constraining influences. Scenario testing in the Statistical models helped identify the Hierarchy of Constraints and specify the pathway to improvement. How to Improve a Business Video link https://vimeo.com/344418155

May 4, 2025

By J. L. Blaylock

Normally, the hydraulic system and structures are considered to be unrelated items. In reality, the two cannot be separated because one affects and depends on the other to function properly. This paper explores the potential failure areas of hydraulic cylinders, and suggests possible methods to prevent failures from occurring. The use of high-strength low-alloy steel in frames is reviewed and the benefits discussed. Fabrication techniques and handling of material are noted in the hope that this knowledge will aid in the repair of frames in the field.

Jan 1, 1979

By C. Díaz, A. D. Dalvi, C. E. O'Neill

Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulphur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is treated in a sulphuric acid plant, and the low sulphur calcine is reduction smelted with coke in an electric furnace to yield a sulphur- deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulphur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries (Ire obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters.

Jan 1, 1994

By Long Han, Beijing General Research Institute of Mining and Metallurgy, Yu Xie, Yunhai Zhang, Yangge Zhu, University of Science and Technology Beijing, Yanbo Shang, Xingrong Zhang

"The first-principles method was employed to study the adsorption of hydroxyl calcium (CaOH+) and hydroxyl (OH-) on hematite and quartz surfaces. The calculation results suggested that OH- preferred to interact with the active Fe sites on the hematite surface, whereas OH- adsorbed on the quartz surface by weak hydrogen bond. Though CaOH+ could easily adsorb on the hematite and quartz surfaces by the formation of Ca-O bond, the covalence formed on the quartz surface was apparently stronger than that on the hematite surface, meaning a stronger and more stable adsorption. CaOH+ adsorbed on quartz surface was mainly through the interaction of O-2p and Ca-3d states, and this interaction on hematite surface was weaker.INTRODUCTIONIron Increase and Silicon Reduction Technology (Yu & Duan, 2002) of hematite is mainly through the reverse flotation (silica is floated away from the iron concentrate). There are two ways to achieve this (Houot, 1983). One is to collect quartz by cationic collector directly; the other is to activate quartz by lime and then collect it by anionic collector. There are two main different views with respect to the mechanism of quartz activation: mono-hydroxyl compound theory (Fuerstenau, Rice & Somasundaran, 1965; Fuerstenau & Palmer, 1976) and surface hydroxyl precipitation theory (Hu & Wang, 1988; Wang & Hu, 1990). The former indicated the formation of the mono-hydroxyl complex is one of the two criteria of quartz flotation. The later theory, on the other hand, suggested that surface precipitation is the adsorption of active species of metallic ion on quartz surface. However, most of those researches are based on the solution chemistry of flotation and little is done at the microscopic level.In this paper, by the help of first-principles calculations, the adsorption models, bonding conditions, Mulliken charge populations and adsorption energies of hydroxyl and calcium hydroxyl ions (OH- and CaOH+) on hematite (001) and quartz (100) surfaces were investigated to find out the lime activation of quartz at atomic level, which is significant for the researches of quartz activation theoretically and practically."

Jan 1, 2016

By Derek J. Barratt

This paper compares a number of operating conventional and semi-autogenous grinding circuits and analyzes them in regard to operating and capital costs, specifically as applied to porphyry copper ores.

Jan 1, 1979

By Royston Colbourne

Objectives Of Presentation - Identify specific risks - A fresh look at risk - Provide a moment reflection on risk - Open discussion on risk A route to solution and advanced thinking.

May 1, 2010

By Xu Feng, Han Shufeng, Zhu Bin, Wang Mingming

Due to urban subway tunnels mostly built in the cities with highly density buildings, the geological and construction conditions is complex, especially certain sections of the subway tunnel will pass through from the foundation of the overpass, therefore the stability and surface deformation control of that section’s tunnel excavation is particularly important. Taking Xi'an Metro Line Three interval tunnel as a research object, we have used FLAC3D simulation to analyze the tunnel’s surrounding soil deformation and tunnel lining stress distribution under bridge foundation with shallow buried covered excavation method. Analysis results show: (1) After the excavation of the tunnel right line, due to the bias of the upper bridge foundation the right of the tunnel showed relatively large deformation. In order to ensure the construction safety, we recommended using the grouting anchor reinforcement on the right side wall to further control the deformation zone. (2) The maximum vertical displacement of the ground occurred in the right wall of the tunnel portion which was due to the intensity of soil outside the grouting range of the arch is low, as a result the deformation is larger; this position requires special attention, strengthening the monitoring measurements of this part is necessary to avoid the large deformation and other adverse effects of the upper portion of bridge foundation. (3) The maximum vertical force area of the initial lining of the tunnel is in the middle of the side wall, while the second lining in this part of forces is smaller, thus at the beginning of the construction of the liner, attention should be paid to this area. On-site grouting or steel bracing reinforce support may be used if necessary.

Jan 1, 2015

By D. Mills, W. J. Brantina

"Mechanical and magnetic characteristics of ferromagnetic materials were investigated by a pulsed ultra-sonic technique. Two instruments, the Ultrasonic Attenuation Comparator (Sperry) and the standard type Reflectoscope (Sperry) were used for measurements of the attenuation of the ultrasonic pulse. The effects of elastic tensile and compressive stresses on the attenuation of annealed and cold worked material are described. In addition, the effects of plastic de-formation, relaxation and aging processes and different ultrasonic test frequencies are reported. The results for Armco iron, SAE 1020 steel, SAE 4340 steel and AISI 420 stainless steel are shown. Under the test conditions, the attenuation was found to be largely a sum of two components; a ""dislocation"" component associated with the losses accompanying the oscillations of dislocation line segments and a ""ferromagnetic"" component associated with the microeddy currents generated by magnetic domain wall oscillations. Either of these components might be dominant depending on the nature of the particular specimen and the test conditions. Finally, the possibilities of using ultrasonics in residual stress determinations, in fatigue studies and in the study of the ductile-brittle transition in ferrous materials, are briefly discussed."

Jan 1, 1960

By Z. Wu, L. N. Y. Wong

The present study develops the numerical manifold method (NMM) as a tool to investigate the progressive failure in rock slopes. The entire processes of the progressive slide surface development related to crack initiation, propagation, coalescence and degradation to eventual catastrophic failure are successfully captured. To overcome the limitation of the original NMM associated with an improper removal of the interface cohesion of the discontinuities, the displacement-dependent cohesion removal method is adopted. Simple examples of failure of rock slopes containing different arrangements of discontinuities are modeled and their results are compared with those based on the popular limit equilibrium method proposed by famous pioneers Jennings and Jaeger. In cases of coplanar non-persistent discontinuities, close results are obtained despite the differences in the consideration of the stress concentrations at the crack/discontinuity tips. In cases of non-coplanar discontinuities, since the influence of the tensile strength is considered by both the Jaegers model and the NMM, the Factor of Safety (SF) values are similar despite the difference in the failure path trajectories predicted by these two models. The results also reveal that the original NMM without the displacement-dependent cohesion removal method is always more conservative due to the improper removal of the interface cohesion. The displacementdependent cohesion method can to some extent alleviate such a limitation.

Jan 1, 2015

By J. E. McMenamin, R. B. Hall

"With the emphasis in the past decade on larger and more efficient equipment for open-pit operations, the Normandie mine of the Asbestos Corporation has followed the trend, switching from the smaller type of percussion drills to down-the-hole rigs. One 5 Y2 -in. percussion drill is still in use, but is limited to a ""smooth blasting"" role or to the control of the slope on final benches.In keeping with the times, an attempt was made to eliminate, as much as possible, the use of high explosives and to maximize the percentage of ammonium nitrate -fuel oil mixture. As the concentration of ground water increased with increased mining depths, small pumps were initially employed for the dewatering of boreholes. This proved unsuccessful, and a hole-blowing rig was built and a conversion to plastic liners made. The acquisition of a bulk-mix AN-FO truck has permitted the changeover from an AN premix to an ammonium nitrate prill -fuel oil combination at the borehole."

Jan 1, 1966

By T. H. Patching, M. W. Mikhail

"The gas sorption and emission characteristic of coals are important to the planning and conduct of mining operations. Methane drainage from coal strata can also provide a supply of fuel in certain circumstances. Gas emissions have also created hazards during the handling and transport of coals and the release of gas also appears to be related to the yield of fine sizes during mining and processing operations.This paper summarizes studies at the University of Alberta on the permeability and gas emission of certain bituminous coals. Permeability of 'solid' samples was found to be drastically reduced by confining pressure. An emission index, .P, which has been related to outbursting behaviour of coals, has also been related to the proportion of fine s in cleaning plants. Gas sorption isotherms are dependent on temperature, moisture content, the gas involved and the type of coal and can be approximately expressed by the Langmuir or the Freundlich equations. Sorption values in sections taken across a given seam were similar but considerable differences were found in . P indices in the different coal layers of a seam.IntroductionThe emission of gases, especially of methane, from coal has been a subject of great interest (and sometimes a matter of life and death), to those who dig and handle coal since it was first mined from underground pit s. Many studies and investigations have been carried out on gas occurrences and emissions but our knowledge of the precise mechanisms of gas sorption, desorption and flow from coal is still incomplete. It is the purpose of this paper to review the principal factors involved in these processes and to briefly rep ort some of the results that have been obtained by studies in the laboratories of the Department of Mineral Engineering, University of Alberta, and Coal Research Laboratory, Edmonton, CANMET"

Jan 1, 1986

By J. Erik Scheel

Overview ? About Hard Creek Nickel ? Turnagain property ? Proposed power line ? Recent Preliminary Assessment ? Favourable economics ? Property Geology ? Mineralization and metallurgical characteristics of major lithologies ? Development of the acNi (ammonimum-citrate H2O2) technique ? Overview of necessary steps ? Results of the technique ? Conclusions

May 1, 2008

By N. R. Thornton

This paper discusses the rapid growth in the application of instrumentation for metallurgical process control. It covers such methods as ultrasonics, pulp density measurements, on-stream X-ray analysis and reagent control, as well as the expanding use of computer control and data acquisition.

Jan 1, 1971

By Rodgers Peale

The Waite mine, as it is locally termed, is situated in the Rouyn district, in the townships of Duprat and Dufresnoy, Quebec, and lies about 340 miles north of Toronto. Due to the impetus given prospecting in the Rouyn district by the discovery, some years ago, of copper-gold ore on the Horne claims, many exploration parties were put into the field. Early in 1925, J. H. C. Waite, C. H. Ackerman, and T. Montgomery staked the claims which now comprise the mine beating their names. Trenching and diamond drilling soon disclosed an ore-body of commercial size and grade, and by the end of 1928 a shaft had been sunk 300 feet and the mine was producing 150 tons of direct-smelting copper ore a day. In the summer of 1925, Dr. H. C. Cooke, of the Geological Survey, made a reconnaissance survey of the property (1), and since that time work of the same nature has been done by several others. MacGregor has published some interesting data on the Amulet mine (2). Using as a background a summer's work on the Horne claims at Noranda, the writer spent the summer of 1929 at the Waite.

Jan 1, 1931

By M. S. Badollet

Introduction The manufacture of some asbestos products involves the use of asbestos in combination with water, cement and granular fillers. This type of production is often called the wet or semi-wet process and requires the use of either pressure or vacuum to eliminate the excess water in the fibrous blend so that the product may develop the proper strength during the curing stage. Asbestos - cement products available today are numerous and are a valuable contribution to the building industry. Their production in quantity depends upon the type of equipment employed, the speed at which it can be operated, and the factors involving the? blending of asbestos, cement, water, and fillers. Assuming that all mechanical troubles at a plant have been eliminated or are under control it is still advisable to study the basic properties of the raw materials used in the asbestos-cement products. The type of cement used is an important factor, but usually the manufacturer of the cement is willing to work with the asbestos development engineer and recommend the proper type to be used for the product. The source of the water should not be overlooked as a general factor involved in the production cycle. Waters containing a high percentage of contamination such as silts, humus, or soluble salts may adversely affect the setting of the cement or cause a slowing down of the production rate in the factory. Asbestos in combination with cement is an ideal material fo1 building products. It is inorganic, will not deteriorate, and can be handled by mechanical equipment with a minimum reduction of fibre length. The many physical properties peculiar to asbestos fibres should be well understood by the manufacturer. They may be briefly enumerated as follows: fibre strength, fibre composition, sliminess, length, harshness, softness, and filterability or porosity. This last named property is important and it is the purpose of this paper to present some basic studies on filtration as applied to production problems.

Jan 1, 1949

By F. J. Munn

"Since 1976, Cardinal River Coal s Ltd. has completed mining in eight pits. In each of these pits, at least one wall has failed, none by design, although not totally unexpected, yet there was no loss of production nor risk to personnel or equipment. Cardinal River Coals Ltd. has been successful in implementing a program to cope with failures and now feels justified in adopting more optimistic design parameters.The wall control program at Cardinal River Coals Ltd. is based on the premise that the walls are going to fail, monitoring is to confirm when. The program consists of monitoring slope movements and piezometric levels as well as structural mapping and visual inspections. In case of excessive movement, the frequency and intensity of the monitoring is increased. If a failure is impending, suitable remedial action is undertaken such as cutting down the crest, building up the toe, depressurization of the wall, artificial support, or a combination of the above. If remedial action is not possible, monitoring permits operations to continue up to near the time of failure.At the design stage, the emphasis is on identifying the potential failure mechanisms and the con sequences of failure. Once the potential failure mechanisms are identified, a monitoring system can usually be employed to give sufficient response time, and providing the consequence of failure is not severe and/ or remedial action can be taken to arrest the movements, then it is practical to mine pit slope s which have a higher probability of failure."

Jan 1, 1985

By A. Liard, H. Sommelet, G. Sauriol

"Description des études qui ant conduit à la conception spécifique du système de drainage de la mine à ciel ouvert. Les approches différentes sont examinées ainsi que la valeur du système recommande.IntroductionLa Division Mines Gaspé de Mines Noranda Ltée exploite un gisement de cuivre par mine souterraine et mine à ciel ouvert à Murdochville, Québec. L'exploitation par mine aciel ouvert a commencé en 1965 avec une operation à flanc de montagne. Elle se poursuit actuellement sous Ie niveau de la vallée dans une fosse dont Ie diamètre est de I'ordre de 800 m (2,600 pi), et la profondeur de 150 m (500 pi) sou s Ie fond de la vallee. Elle doit atteindre une profondeur de 360 m (l, 180 pi) sous Ie fond de la vallee , avec des murs hauts de 360 à 490 m et des pentes moyenne de 44°. Le rythrne d'extraction est actuellement de 85,000 tonnes par jour.Dans Ie cadre des etudes entreprises par les Services Techniques de la Division Mines Gaspé, la compagnie Géomines Ltée a été consultée pour étudier les conditions hydrogéologiques et hydrologiques locales et participer a la conception d'un système de drainage superficiel et souterr ain. Un tel systerne de drainage visait: a éviter les importantes venues d'eau qu i affectent I'exploitation en periode de crue; amaintenir les pressions hydrostatiques au sein des parois de la fosse dans les limites imposees par les etudes de stabilite des pentes réalisees par la Mine.Les principales étapes de cette etude ont porté sur: la collecte et la compilation des données sur la géologie, l'hydrologie et l'hydrogeologie du site; . la détermination des caractéristiques hydrauliques du milieu rocheux à partir d'études structurales et de test s de perméabilité;"

Jan 1, 1981

By Greg Johnson

Maintenance needs information about assets to optimize availability and production needs information about performance and consumption to maximize output. In considering both these needs together as, ?Asset Optimization?, the information systems that support them are critical. The theory of Asset Optimization derives from the Lean Manufacturing concepts developed by Toyota, but some changes are required to apply this to mining operations. In particular, mining operations require automated systems due to their geographic spread and they need a strong emphasis on capturing under-performance losses as well as delays and stoppages in production. Leading metal miners and coal miners alike have applied these systems to good effect in the last 10 years. The concepts developed initially in minerals processing plants are now being applied to the mines themsleves as well as the mining logistics chain. Production increases of 5?10% are achievable with the right implementation and consideration of the some key lessons learnt in the last 10 years. Putting these lessons into action is one key step in the goal of optimizing asset performance and thus utilizing the resource at lowest cost.

Aug 1, 2013

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

By Didier Fohlen

Three Policy Shifts to enhance IFC?s Accountability ? Comprehensive and dynamic treatment of social, health, safety and environmental risks ?Covers a range of risks encountered by clients in emerging markets ?Framework to anticipate risks and to address them as they arise ?Includes community development, biodiversity, human rights ... ? Effective principles to guide an outcomes-based approach ?By clients and IFC ?Focus on broad community support and value-added sustainable development initiatives Enhanced governance, transparency and disclosure

May 1, 2006