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By D. M. Ziebarth

"Normal sequence of operations to develop a new underground mine is: construct and outfit headframe for shaft sinking, sink shaft, construct and outfit shaft sump, develop shaft station and shaft bottom steel. In an effort to reduce the overall project schedule, an innovative plan was developed to install service shaft steel below station level, prior to the completion of the shaft sinking effort. To better evaluate the construction of this substantial steel tower, a preliminary constructability evaluation was conducted, including the best method of supporting the main tower; from the bottom, middle or top of the tower. The design criteria and plan involved: •,Develop access from existing service shaft, 25 km underground •,Use of materials to maximize strength while minimizing corrosion exposure •,Estimating the location of the shaft centerline •,Over excavating the station and shaft below station to allow future shaft steel repositioning •,Designing the tower steel for modular installation •,Incorporate commissioning considerations, such as suspension of the cheese weights during steel installation •,Provision for covered stair access to shaft bottom •,Enclosed shaft envelope with open panels to allow visibility and ventilation The design approach was innovative and this paper will describe the design principles and challenges encountered while providing insight into the solutions developed and implemented; especially the modular construction and installation methodology. INTRODUCTION In an effort to expand the mining operations, a plan was developed to construct a new service shaft closer to the new mine workings and convert the existing service shaft to a production shaft at the Potash Corporation of Saskatchewan Inc. (PCS now Nutrien) Rocanville Potash mine in southeast Saskatchewan. The new service shaft required a multi roped friction hoist operating a cage / counterweight, rope guided conveyances to support the operational requirements. The service shaft is an integral part of the mining infrastructure as it provides access to the underground workings, transport personnel and materials underground for operation and maintenance of the mine. The shaft also allows for services required for safe operation of the underground mine, power supply, controls, communication, dewatering and fresh water supply."

Jan 1, 2019

By Steve Simard

Suite aux excellents résultats, obtenus avec la technologie des détonateurs électroniques dans des chantiers longs trous de grandes dimensions, nous avons décidé d?étendre cette technologie dans les ouvertures, dans le dynamitage de piliers et dans différents chantiers complexes. Cette technologie nous a permis d?effectuer l?abatage de chantiers avec un très grand nombre de trous sans détériorer le terrain. L?équation est bien simple avec les détonateurs électroniques, plus gros sont les dynamitages moins de fois les épontes se font ébranler, moins de blocs d?effondrement se retrouvent dans les points de soutirages entre les dynamitages et plus la fragmentation est meilleure. La flexibilité d?opération que nous avons obtenu avec les détonateurs électroniques est difficilement quantifiable, mais elle nous a permis de maintenir notre rythme de production mensuelle même avec certains chantiers complexes. Il est bien certain que l?utilisation des détonateurs conventionnels a encore sa place dans une mine conventionnelle comme Beaufor, mais l?utilisation des détonateurs électroniques a aussi sa place dans certaines situations spéciales. Pour terminer, bien que la technologie des détonateurs électroniques soit encore dispendieuse, nous pensons encore l?utiliser pour optimiser certains dynamitages et ainsi maintenir notre flexibilité d?opération.

Oct 1, 2004

By Roxanne Scott

Outline ? Overview of Community Investment in the Mining Sector ? Emerging Good Practice: ?Strategic Integrated Community Investment? ? Assessing Local Context: ? Institutional Assessment ? Partnership Assessment Approaches to Community Investment Isolation: No proactive engagement in community development Ad hoc philanthropy: small infrastructure, sponsorships, donations Strategic philanthropy: Community proposes options for development Company decides what to do and carries it out, e.g. building schools, health posts, roads Strategic integrated community investment: ? Aligned with government/community development goals and priorities ? Communities and government involved in decisions and execution ? Focused on training and capacity building ? Partnerships ? Continuation in absence of company support Measured returns on investment

May 1, 2010

By A. I. Collins, D. Danninger

Newmont has installed advanced control and online optimization on the dry grinding circuit and both roasters on its Carlin Trend refractory ore treatment plant. Subsequently, Newmont has developed a master plan for institutionalizing advanced control and optimization on all its processing units. Newmont is committed to a program of applying advanced control and optimization from crushing of ore to pouring of gold. This paper describes Newmont's experience with implementing advanced control and optimization and the benefits received. In addition, identification of advanced control and optimization opportunities and their economic justification is discussed.

Jan 1, 2005

"The Code was developed in 2004 through the Collaboration Agreement between Institution of Mining Engineers of Chile (IIMCh) and the Ministry of Mining (Chile) in Dec 2002. It is an amalgamation of current practices with respect to standards and procedures for exploration prospects, mineral resources, and reserves for the purpose of public reporting. Certification is required to prepare and issue information on mineral assets according to the guidelines that regulate the technical, economic, and environmental aspects that satisfy the conditions set by the Chilean capital and financial markets.The Mineral Resources Committee of the Instititution of Mining Engineers of Chile (IIMCh) is pleased to introduce theCode for the Certification of Exploration Prospects, Mineral Resources and Reserves which is the result of a Collaboration Agreement between the IIMCh and the Ministry of Mining established in December, 2002.This code synthetizes the present practice of the mining industry in regard to standards and procedures applied to exploration prospects, mineral resources, and reserves with the purpose of reporting publicly on financial instruments based on these mine assets in the capital markets. These standards follow general criteria already adopted and applied by capital markets in those countries characterized by a very dynamic and well developed mining sector such as Australia, Canada, Southafrica, United Kingdom, and others. The work done by the Mineral Resources Committee of the IIMCh has had the recognition of the Combined Reserves International Reporting Standards Committee (CRIRSCO) that leads the establishement of an international code in these matters. CRIRISCO is an entity formed by representatives of the countries previously mentioned, a representative of the Society of Mining Engineers of the UStates and a representative of the IIMCh. The Institution thanks the Ministry of Mining, the representatives of these Ministry in the Mineral Resources Committee, and specially the Minister of Mining, Sr. Alfonso Dulanto Rencoret due to the genuine support given to the IIMCh in the preparation of this Code.The Institution also thanks the Superintendencia de Valores y Seguros (SVS) because of the help given continuously to the Committee as well as by the interchange of opinions and suggestions received during the preparation of this document."

Jan 1, 2003

By E. T. W. Bailey

A HISTOR Y of the development and application of instruments, from the simplest U gauge to a modern indicating recording controller, would contain many interesting accounts of difficulties experienced and over-come. Important as is the history of development to any branch of science, this phase will, of necessity, have to be omitted from this paper and remarks confined to the results from the use of instruments in their present form. The steel industry bas, in the past decade, become increasingly instrument minded. More than ever, economy and adherence to doser specifications are demanded, and any tool that will aid in attaining these objectives by intelligent application and use finds a ready acceptance. The open-hearth furnace bas offered a field for instruments which is different from almost any other and one in which even a small percentage saved in operating costs may represent a considerable sum. Nevertheless, this department of the steel industry has been more cautions than most others in accepting the benefits which automatic control bas given on many other types of industrial furnaces, and one is puzzled why open hearths have not more generally benefited by the application of controlling instruments. The furnace operator bas to adjust the same three main valves that control fuel, combustion air, and stack draft as on most other furnaces, with the additional regulation of reversing the furnace. He is just as aware of the importance of proper draft control and correct air volume to burn most economically the applied fuel as any good boiler-plant engineer. What, then, are the special conditions that pertain to the open-hearth furnace?

Jan 1, 1939

By J. Scrimgeour

"The word ""instrumentation"" has expanded from its original meaning, which in engineering perhaps referred to measuring apparatus alone. In its broadest form, it now includes sensors, display instrumentation, standard pack-aged controllers and, most recently, the use of stored program computers for on-line process control. The paper traces the evolution, in tutorial form, of the successive application of mechanization, measurement instrumentation, automatic control, central operating systems, programmed control, process computer control, direct digital control and, finally, hierarchies of computers used for process control and corporate management as a fully integrated business system. In the field of industrial minerals, the cement industry has seen the most widespread acceptance of these techniques. Computer control has been accepted as the way of life for the blending of chemical materials and for on-line control of the cement kiln. Accordingly, the cement application is selected for further presentation in the paper. This illustrates the trend progressing from control of single loops on process variables toward the objective of total control of the product quality. The economic justification for instrumentation, centralized control, automatic control and computer control is .discussed with reference to savings in fuel, maintenance, operating labour, depreciation, power and product quality improvements."

Jan 1, 1967

By A. Mular, T. Bond, G. D. Farnell, J. F. Kingston

"ABSTRACT:-A 60—cm semiautogenous grinding-(SAG) mill was designed -for continuous wet operation in closed circuit with a vibrating screen. The circuit is fully instrumented and automated. Part of the control system incorporates Foxboro SPEC 200 controllers around the pump box to maintain level. The rest of the control system involves an ACTION model BC2 basic direct digital controller that handles all other inputs/outputs and contact closure sensing:·The success of the control system is attributed to the uniqueness of specially designed mass flow metering systems. Various control strategies are possible. Employed to date has been control of a mill load set-point by cascading the deviation from load set-point as the set-point to the fresh feed rate ""controller"". Mill feed water is ratioed to total flow rate of solids fed to the mill. The performance of the circuit is being correlated with the performance of full scale SAG circuits in British Columbia to develop models, to assess the feasibility of scale up and to investigate the effects of design variables on responses such as circuit throughput. 1 INTRODUCTIONWhere ore types are appropriate, semiautogenous grinding and/or autogenous grinding (AG) has replaced conventional grinding. Secondary/Tertiary crushing plants are thereby eliminated so that capital expenditures are less and overall comminution costs can be lower (Barratt 1982). To establish the suitability of an ore for SAG circuits, pilot scale tests with 1.7 to 1.8 M diameter mills are often conducted. At least one test per ore type in a deposit has been necessary. Often, each test involves a large amount (up to 50 tonne) of sample, so that the testwork can be expensive and may discourage the use of SAG or AG circuits. However, MacPherson (1977) has employed a continuous 45 cm dry Aerofall mill circuit closed with screens and an air classifier to determine whether ores are suitable for SAG milling. The amount of sample per ore type is of the order of 60 kg or less. Thus an established SAG mill scale up procedure that employs small circuits is highly desirable.The purpose of this paper is to describe a small 60 cm wet continuous SAG/ AG mill pilot circuit assembled at the University of British Columbia to study the feasibility of scale up, to assess the influence of design variables, to develop mathematical models and to evaluate the effects of alternative control strategies on circuit performance"

Jan 1, 1988

By L. Kilpinen, K. R. Kay, H. B. Fowler

"FOREWORDThe International Nickel Company of Canada has built four ore concentrating plants since 1950. The fifth and largest is now under construction. In each successive plant, the level and type of instrument control and sophistication of control techniques have increased as experience was gained. The type of control progress is illustrated in Fig. 1.At Frood-Stobie the high degree of instrumentation and the level of control were made possible by the constant evolution of techniques and improved instrument hardware technology. We have established in practice concepts that are sound, although many modifications to instrument sensor types and locations 1-rere often necessary. It is generally true that at other existing Inco mills, it is possible to run ""all manual"" for protracted lengths of time because of operator availability and dependence. The Frood-Stobie Mill is the exception, and it is the degree of reliability of the instrumentation hardware and level of maintenance that has made this possible."

Jan 1, 1971

By W. A. Gow, H. H. McGreedy

It is believed that many of the problems encountered in the operation of gold cyanidation plants are difficult to resolve due to the lack of sufficient and reliable in-formation regarding the variations and actual values of operating variables at any given time. The application of instruments to monitor the more important variables in the cyanidation process should result in more efficient plant operation and a better understanding of the process. The use of pH and conductivity sensing devices for alkalinity measurements, a monitor to determine the dissolved oxygen content of plant solutions, a continuous cyanide titrator and sonic control of grinding circuits are discussed. Although the discussion is oriented toward the cyanide process, much of the paper is applicable to other ore treatment operations.

Jan 1, 1966

The #3 Shaft at Brunswick Mine, Bathurst, New Brunswick, Canada, intersects a soft graphite zone just below the 3400 Level. Ground movement within this zone causes the concrete liner of the shaft to be deflected towards the shaft?s interior, affecting the steel framework of the conveyance. In some areas, the clearance between the cage and the liner has been reduced to less than 2 cm, which is a concern. An innovative surface-mounted extensometer was designed in 2008 to monitor potential movements of the shaft?s liner. Four such novel extensometers were installed in the shaft for the surveillance of a particularly critical 3.0m by 5.5m area. This article describes the approach taken to instrument the shaft, the principle of the new extensometer, as well as the performance of the instrumentation following its installation.

May 1, 2009

By Fidelis T. Suorineni

HydraboltTM is a Swellex-type dowel support element developed and manufactured by New Concept Mining in South Africa. Like Swellex, the HydraboltTM is a folded tube which can be inserted into a larger diameter hole without pushing. It is then activated by injection of high pressure water which inflates the folded tube to intimate contact with the walls of the borehole at a set pressure, normally 25 MPa. Unlike Swellex however, the set water pressure at the end of the inflation is maintained throughout the life of the dowel. An integral non-return valve makes this possible. The HydraboltTM is being investigated as a possible stress change measuring cell. This paper presents the results of closed form solutions, numerical modeling and laboratory test to date. Preliminary results indicate that the HydraboltTM can be used as a stress change monitoring cell in addition to its conventional role as a rock mass reinforcing element. If successful, the HydraboltTM will supplement microseismic monitoring systems in rockburst-prone ground conditions where they will give quantitative stress change data for both mine design model calibrations and means for proactive safety measures.

Oct 1, 2010

By L. Bos

The availability and reliability of large grinding mills and their Gearless Mill Drives (GMDs) are of paramount importance for the grinding process. Although GMDs have been in service for decades, and are known for their operational efficiency (reliability and robustness with reduced operating cost per ton), compared to conventional drives, in the last decade due to certain reasons some failures led to serious unscheduled shutdowns and significant insurance events. The majority of these notable "insured" failures have happened on GMDs installed on relatively large mills, as the financial impact of a failure is proportional to the through-put of the mill. Despite the occurrences of these events, as mining operations are driven by lower ore grades and the ability to continue reducing operating costs per ton, the trend for having larger mills is still very present and there is no reason why this trend should not continue. It is obvious that if not handled correctly, the possibility of large value GMD loss events, coupled with the continuing increase in mill size or required availability and reliability targets, could potentially lead to major conflicts as it becomes difficult for the insurance companies to judge the risk and hence may result in hesitation to insure these grinding circuits. This paper will not only describe the conflicting situation from both an insurer's perspective and from an equipment supplier's perspective, but also how these conflicting challenges can be successfully mastered. It has to be noted that not only the mining companies themselves, but also their insurance companies and the involved equipment suppliers have a common interest: to reach the highest availability and reliability in order to avoid or at least minimize unscheduled shut down times, and most importantly prevent unplanned events that result in extended production stoppages or reductions in through-put of GMD driven mills. From the very beginning onwards, the complete service concept together with emergency plans must be integrated on every level in the design of the grinding circuit. This approach must be implemented continuously and without compromises by all involved parties during all following stages, such as basic design, detail design, manufacturing, quality inspection and testing, packing, transportation, storage, installation, commissioning, operation and maintenance. The concept of formal risk analysis related to mill operations, maintenance and spare parts strategies must be an integral part of mining companies? decisions related to the selection for installation and continued use of large mills powered by GMDs. The service concept in place for operating mills shall also have a clear focus on very early detection of any abnormalities, so that the risk can be mitigated and unscheduled shutdown times avoided. However, if a major failure occurs, then procedures and tools shall already be available in order to ensure that production impact is minimized.

Jan 1, 2012

By J. Koponen, M. van de Vijfeijken, L. Bos

"The availability and reliability of large grinding mills and their Gearless Mill Drives (GMDs) are of paramount importance for the grinding process. Although GMDs have been in service for decades, and are known for their operational efficiency (reliability and robustness with reduced operating cost per ton), compared to conventional drives, in the last decade due to certain reasons some failures led to serious unscheduled shutdowns and significant insurance events.The majority of these notable ""insured"" failures have happened on GMDs installed on relatively large mills, as the financial impact of a failure is proportional to the through-put of the mill. Despite the occurrences of these events, as mining operations are driven by lower ore grades and the ability to continue reducing operating costs per ton, the trend for having larger mills is still very present and there is no reason why this trend should not continue.It is obvious that if not handled correctly, the possibility of large value GMD loss events, coupled with the continuing increase in mill size or required availability and reliability targets, could potentially lead to major conflicts as it becomes difficult for the insurance companies to judge the risk and hence may result in hesitation to insure these grinding circuits. This paper will not only describe the conflicting situation from both an insurer's perspective and from an equipment supplier's perspective, but also how these conflicting challenges can be successfully mastered. It has to be noted that not only the mining companies themselves, but also their insurance companies and the involved equipment suppliers have a common interest: to reach the highest availability and reliability in order to avoid or at least minimize unscheduled shut down times, and most importantly prevent unplanned events that result in extended production stoppages or reductions in through-put of GMD driven mills.From the very beginning onwards, the complete service concept together with emergency plans must be integrated on every level in the design of the grinding circuit. This approach must be implemented continuously and without compromises by all involved parties during all following stages, such as basic design, detail design, manufacturing, quality inspection and testing, packing, transportation, storage, installation, commissioning, operation and maintenance. The concept of formal risk analysis related to mill operations, maintenance and spare parts strategies must be an integral part of mining companies’ decisions related to the selection for installation and continued use of large mills powered by GMDs. The service concept in place for operating mills shall also have a clear focus on very early detection of any abnormalities, so that the risk can be mitigated and unscheduled shutdown times avoided. However, if a major failure occurs, then procedures and tools shall already be available in order to ensure that production impact is minimized."

Jan 1, 2012

By C. Kunze

ABSTRACT Although closure sureties cover works that are carried out during the existence of a mining company, certain liabilities are not known when the surety is established and become apparent only in a late stage of the closure phase, or even after the site has been relinquished. This paper supports the concept that these financial risks lend themselves to insurance solutions. Making insurance for unknown liabilities mandatory while defining unambiguous legal conditions could create a viable market for insurance products, provide a sufficient statistical basis for the calculation of premiums, and reduce costs.

Jan 1, 2013

By Pierre C. Vieillescazes

MIGA: Unique Multilateral Risk Mitigator ?A World Bank Group agency established in 1988 to promote and facilitate sustainable foreign direct investment in emerging coufacilitate countries ntries (north(north--south and southsouth south--south) ?Guarantees equity and debt and many other types of investments against non-commercial risk. ?Can cover the following type of risks: ?Expropriation ?Breach of Contract ?Currency Transfer and Inconvertibility ?War and Civil Disturbance ?Non-Honoring of Sovereign Financial Obligations

May 1, 2010

By A. Broussaud

The paper describes the advanced grinding control system implemented at Newmont Ahafo gold mine, Ghana in 2009 and 2010. It shows how the different components of the Advanced Process Control (APC) system cooperate for increasing plant performance. The SABC circuit processes hard rock from different pits mixed with a variable proportion of oxides. The control strategy is designed to address specific disturbances, including start/stops of pebble crushers, unavailability of oxides, changes in rock size distribution resulting from segregation in the stockpile, and changes in ore type and hardness. The system consists of an expert system per se with extensive use of fuzzy logic, supplemented by an online dynamic model of the process used as a soft sensor, a VisioRock? rock size measurement system over SAG mill feed before addition of recycled pebbles, and an AudioMill? system to analyze the SAG mill sound and detect impacts on liners. All these components are embedded in the same OCS© software platform, which, among other benefits, makes it easy to support the entire system remotely. The paper details the physical constraints and the variables that are manipulated. It describes the control strategy and the contribution of each component of the system. It also describes the project implementation and the performance of the system. In addition to a strong involvement and support of management, the very good acceptance of the operators has been facilitated by the remote access system that made it possible to immediately modify the system each time it was needed during the baby sitting phase. The system made it possible to increase gold production significantly through increases in tonnage and recovery thanks to a better control of the grind size through a stabilization of the secondary ball milling circuit and an improvement of the operating conditions of the classifying cyclones.

Jan 1, 2012

By O. Guyot, A. Broussaud, M. Revalor, G. Legrand, D. Kok, E. Roux

"The paper describes the advanced grinding control system implemented at Newmont Ahafo gold mine, Ghana in 2009 and 2010. It shows how the different components of the Advanced Process Control (APC) system cooperate for increasing plant performance.The SABC circuit processes hard rock from different pits mixed with a variable proportion of oxides. The control strategy is designed to address specific disturbances, including start/stops of pebble crushers, unavailability of oxides, changes in rock size distribution resulting from segregation in the stockpile, and changes in ore type and hardness.The system consists of an expert system per se with extensive use of fuzzy logic, supplemented by an online dynamic model of the process used as a soft sensor, a VisioRock™ rock size measurement system over SAG mill feed before addition of recycled pebbles, and an AudioMill™ system to analyze the SAG mill sound and detect impacts on liners. All these components are embedded in the same OCS© software platform, which, among other benefits, makes it easy to support the entire system remotely. The paper details the physical constraints and the variables that are manipulated. It describes the control strategy and the contribution of each component of the system. It also describes the project implementation and the performance of the system. In addition to a strong involvement and support of management, the very good acceptance of the operators has been facilitated by the remote access system that made it possible to immediately modify the system each time it was needed during the baby sitting phase.The system made it possible to increase gold production significantly through increases in tonnage and recovery thanks to a better control of the grind size through a stabilization of the secondary ball milling circuit and an improvement of the operating conditions of the classifying cyclones."

Jan 1, 2012

By Oyku Selimoglu

The key to successful mine production plan and subsequent operation is efficient mine layout design and optimization. Pit layout design and optimization allow the delineation and extraction of mineable reserves and the minimum waste subject to slope stability, economic, quality and quantity constraints. Many design and optimization software packages have been developed to aid this intensive and challenging process. These packages include VULCAN, SURPAC, DATAMINE, GEMCOM, MICROLYNX, MEDSYSTEM and MINESIGHT. These software packages are developed as integrated computer-aided systems used for database creation, survey, geological and geostatistical modeling, mine planning and production optimization and environmental modeling. In Turkey, many mining companies still plan and design mine layouts with traditional hand methods. In this study, VULCAN has been used to design and optimize the Eti-Bor A.S. Kestelek Boran Open Pit Mine in Western Turkey. The main objective is to show the company the superior advantages of mine planning software for designing and optimizing mine layouts over the traditional hand methods. Drill hole data used by the company to estimate the reserves for planning are used in this study. The ore grade varies between %1,04 B2O3 to %47,33 B2O3. The pit toe and crest strings are projected using variable batter angles and berm distances. On the north side, batter angle is 180 and berm distance is 25 meters, on the south side, batter angle is 320 and berm distance is 15 meters. In addition to that open pit bench height is 10 meter. The concepts of block modeling are applied to the Kestelek open pit mine with detailed ore grade modeling for each block. The Lerchs-Grossmann?s algorithm is used to optimize this mine based on the block model, the economic block values for each block and the underlying field constraints. The results from VULCAN were similar to the estimates by hand. The reserve estimates from VULCAN is 13,192,870 tons compared with the hand estimate of 13,200,000 tons, overburden estimates of 15,622,889 m3 compared with 15,000,000m3 obtained by hand with a stripping ratio 1.18:1 (m3:ton) from VULCAN versus 1.14:1 (m3:ton) from hand estimate. Vulcan improves the efficiency, speed and reproducibility of the planning results. It provides mining engineers, geologists and surveyors with a cost-effective modular system for assessing and planning the mine layouts. Furthermore, Vulcan?s specific modules allow efficient access and manipulation of databases, open pit mine design, block models, optimized 3D mine layouts, and more. However, for competitive business in Eastern Europe, VULCAN should improve its software support. Effective training, help desk support systems and nearby distributors with just-in-time solutions to company problems will generate competitive business for VULCAN.

May 1, 2007

By Mario A. Morin

Over the years, several sources have stressed the need to better integrate the underground mine design and planning processes. The belief is that with better integration, better designs and plans will result - designs that are ?optimized?. Some researchers have focused their efforts on data integration, others have looked at closing the loop between production control & monitoring with mine planning & scheduling. In spite of all these efforts, fully integrated applications combining geological modeling, stope design and geomechanics, mine planning and scheduling, rock extraction and material handling system design, mine support systems, economic analysis with production control do not yet exist for the underground hard rock mining industry. There are several likely explanations - some economic, some technical. It is certain that the design and planning processes are interrelated and interdependent and thus are extremely complex to describe and understand. The mining engineer has an appreciation of the complexities involved - but how does he convey this knowledge to a programming team responsible for developing an integrated design & planning system. This paper will focus on software engineering methods, and other possible approaches, to describe and manage the complexities inherent in the underground mine design and planning process and the development of an integrated computerized system.

May 1, 2001