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By Joseph L. Petrillo

In July 1997, Kvaerner Environmental signed a unique contract with Echo Bay Alaska called the Transfer Risk and Accelerate Closure (TRAC). The contract called for Kvaerner to assume the responsibilities and obligations associated with closeout of the Alaska-Juneau (A-J) Mine. Kvaerner is an international engineering and construction company with global interdisciplinary experience in the mining industry and environmental remediation. Echo Bay’s requirements called for Kvaerner to: •Provide a fixed price for closure with no change orders. •Negotiate, prepare and implement a final closeout plan as outlined by Echo Bay. •Complete a closure program that exceeded current regulatory requirements. •Improve, expand and maintain a proactive public and community relations program. •Hire Echo Bay employees where possible. •Provide adequate performance guarantees and judicial relief of environmental claims.

Jan 1, 1999

By Adrian Dance

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

May 1, 2003

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

Jan 1, 2005

Mine rehabilitation is a sustainability issue that has been revisited ad infinitum; however, the persistent lack of demonstrated on-the-ground performance and an increasingly intractable rehabilitation liability in Queensland continue to erode the credibility of the mining industry and regulatory bodies. For at least ten years the need to change the current, process-based approach to rehabilitation to an outcomes-based approach has been apparent. The ISO 14001 series temporarily diverted attention from this important point, however it would appear the limitations of an ISO 14001 approach are now more widely accepted. It is proposed that a successful outcomes-based approach cannot be achieved without meaningful community engagement. The apparently intractable nature of the rehabilitation issue will continue to generate conflict and criticism unless all stakeholders are encouraged to participate in the process of developing robust and practical outcomes for rehabilitation. Sharing the responsibility will ensure the best possible outcome. It is important to recognise the valuable resources inherent in community groups, many of whose committed volunteers have considerable expertise in relevant areas. Community groups should not be seen as adversaries but as allies in the process of solving problems that affect the wider community. Several projects that can be seen as test cases for the engagement of stakeholders exist, and in this paper the process of achieving multiple stakeholder engagement in the context of Environmentally Sustainable Development is discussed.

Jan 1, 2002

By H. Araneda

Throughout Chile?s history, mining has consistently been a leading industry in the country. The 1990s marked the beginning of a boom in Chile?s mining industry, especially in copper mining, due to both foreign and local direct investment in the sector. Mining?s contribution to the GDP was 15.6% at current prices in 2009, and it accounts for 56% of the country?s exports. Chile?s copper market share reached 35% in 2009. The investment portfolio in mining in Chile for the coming decade has been estimated at 90 billion US dollars. The acute scarcity of human resources currently experienced by the mining sector in Chile will be accentuated in the coming decade as a result of this scenario of investments. The situation is, additionally, similar to the one confronted by other countries involved in the mining industry such as Australia, South Africa, Canada, and in Latin America includes, Peru, Colombia and Brazil. A study carried out by Fundacion Chile, ¨Labor Force in the Chile Mining Industry, Diagnostic and Recommendations, 2011-2020? shows the projected labor shortage for the operation of projects in the development stage, considering only the requirements of the process of extraction, processing, and maintenance. The demand, accumulated incrementally, will be around 115,000 technically skilled workers, professionals, and qualified workers. This figure refers to the operational work force, and does not include the human resources that will be required for the prior stage of the engineering and construction of the projects (brownfield and greenfield). The demand for technically skilled workers and professions for the stages of engineering and construction of the projects that have already received investments is estimated to be 190,000 people for the period 2012-2020. The peak of the demand for engineering is 2012, with a figure that surpasses the 12,000 professionals for all of the engineering specialties. The analysis of the formation of human resources at the tertiary level (where tertiary includes technical/vocational and academic degrees at the undergraduate level) for mining and related majors demonstrates that the programs are scarce with a bias toward theoretical contents and that they are excessively long (40% longer than comparable programs in Australia, Canada, and in OECD countries). The completion rates are low, especially in the technical-vocational programs, which have a completion rate of only around 30%. Finally, the rates of attraction of technically skilled labor and professionals towards careers in mining are insufficient to reduce the identified skill gaps. In the case of university professionals such as geologists, mining engineers and engineers in metallurgy, 80-90% will work in mining. In the case of graduates of relevant majors, that cover skills also utilized by other industries, not only mining?such as maintenance workers, operators of fixed and mobile equipment, etc.?the mining sector appears to be unattractive for reasons such as shift schedules, geographical location of work sites, and other factors. On the basis of the available diagnosis a strategy for the sector has been developed (Workforce Development and Skills Strategy) whose objective is (i) to define a Mining Qualifications Framework to identify the critical roles to be filled (ii) to start, with public resources, a ¨fast-track? training program to assure the availability of at least 28,000 operators (machinery operators, truck drivers, etc.) and maintenance specialists in 2015 (iii) to promote the development of training hubs for mining with learning technologies to train technical labor and professionals on the basis of world class standards (iv) to design and implement a campaign oriented toward the perception of mining as an attractive field of employment opportunity (v) to develop curricular innovations for tertiary education programs, on the basis of international benchmarks. Keynotes: Chile, mining, copper mining, skilled human resources

Sep 1, 2012

By S. C. Essack

"Tenova Pyromet has designed a slag flow control valve that throttles the flow of slag in order to control the tapping rate. In addition, the valve has proved to be a reliable tool for closing the furnace during normal operation as well as emergency conditions. The valve makes use of a water-cooled copper element that is hydraulically operated and attached directly to the slag tap-hole. The equipment is compact, simple to maintain, and cost-effective to purchase and install. It can be retrofitted to most existing slag tapholes with minimal modifications.During the development phase, finite element method (FEM) and computational fluid dynamics (CFD) software was extensively used to model predicted operating conditions and to optimize the design. By using CFD, it was possible to understand the flow patterns inside the copper and to optimize these to improve overall performance.The slag valve was installed and commissioned in 2011/2012 on a 12 MW furnace as part of a new mineral wool plant in the USA. It has performed well since its installation despite operating under conditions in excess of the original design criteria. During the first 6 months of operation it quickly became the preferred method of closing the furnace, although the design intent was for occasional use during emergency shutdown conditions only. Since replacing the mudgun as the main method of closing the tap-hole, a few minor changes have been made to the installation in order to cope with the increased heat load and much higher frequency of use."

Jan 1, 2014

By T. Braun, J. Parker

On June 25, 1999, BHP Billiton (BHPB) announced the suspension of operations at the BHP Copper Inc.(BHP) San Manuel copper mine in Pinal County, Arizona. Subsequent to this announcement, BHPB aggressively pursued a number of alternatives for the underground mine and open pit facilities, including continued curtailed operations, sale to a qualified mining operator and closure of the property. After consideration of these various alternatives over a 2.5-year period, BHPB announced final closure of the mine site on January 15, 2002.This paper describes how the BHPB charter and HSEC policy apply during the closure process.

Jan 1, 2004

By Alan Dahlstrand

The Jamestown Mine is a 6.3-kt/d (7000-stpd) open-pit gold mining operation located in the central portion of California's historic Mother Lode district. Most early production from the Jamestown area occurred in underground operations from 1906 through 1916. Pit production began at Jamestown in early 1987 and continued until July 1994. Although additional mineral resources existed, they were deemed to be uneconomic. About 23.3 t (750,000 oz) of gold were produced from pit operations, compared to 31 t (100,000 oz) from early underground mining. Recent operations at Jamestown included two open pits, a flotation mill and a flotation tailings facility. Flotation concentrates were produced in Jamestown and shipped to Yerington, NV for cyanide leaching in a carbon-in-pulp (CIP) circuit.

Jan 1, 1995

By H Jones

Closure cost estimates may be generated at any stage of a mining operationÆs life; commencing with the initial prefeasibility studies and continuing through to the final decommissioning cost estimates. However, not all mine closure cost estimates are necessarily the same. Cost estimates will vary depending on the purpose for which they are prepared, the organisations requiring or undertaking the estimate and the stage of the mining operation. Different organisations can legitimately arrive at disparate cost estimates for closing the same mine because the organisations have different reasons for requiring the estimates. Another, equally valid, reason for potentially wide variations in cost estimates by different organisations on the same mine site is the different definitions of æclosure costsÆ used by different estimators. This paper considers the different approaches by different organisations including operating companies, government authorities and financial organisations and uses a hypothetical example based on practical experience to illustrate some of these differences in estimation methods.The paper suggest that a more consistent approach to closure cost estimating in the Australian mining industry would assist mining companies, governments, the accounting industry and the broader community to better understand this complex component of mine planning. One possible approach to closure cost estimating is briefly outlined.CITATION:Jones, H, 2012. Closure cost estimation - All things to all men?, in Proceedings International Mine Management 2012, pp 115-124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By J. J. Antony

As the first wave of precious metal heap leach closures and reclamation projects occur, a number of companies are being hit with costly surprises. While this paper refers specifically to U.S precious metal projects, it could be conceptually directed at copper leach operations and acid rock drainage (ARD) problems on an international basis. ARD is Mother Nature's version of heap leaching, only with different products and timing. Although many precious metal deposits tend to be small in comparison with some base metals systems (porphyry copper deposits), adjacent or nearby discoveries have extended the operating lives of numerous precious metal mines. Now, depleted reserves, several years of relatively depressed precious metals prices and some properties with technical difficulties have resulted in numerous mine closures. As a result, our industry is getting a diverse and comprehensive initial look at mine closure and final reclamation. The situation has been further complicated by the evolutionary trend in regulations and their enforcement and increasing public and political awareness of all environmental issues. Concurrent (proactive) vs. deferred (reactive) reclamation and a realistic early appraisal of ultimate reclamation and closure requirements, not just regulatory compliance, need to be a part of project design. The U.S. and Canada are the current fertile testing grounds and have set the design, regulation and closure standards for the next wave of operations in Latin America, the CIS (?), etc.

Jan 1, 1994

By M Slight, H Lacy

In recent times, with the global mining industry’s focus on sustainable development there has been a significant focus on mine closure and rehabilitation performance and reporting through the development of the International Council on Mining Metals (ICMM), the Global Reporting Initiative and the Equator Principles. In addition, financial reporting obligations under International Financial Reporting Standards and the Sarbanes Oxley Act (2002) have also led to better understanding and improvements with industry closure performance, liability management and reporting.Under these sustainable development principles and financial reporting obligations, mining companies are required to consider mine closure planning and associated cost estimates across all life cycle phases of the mine. Internal processes have been developed within mining companies to better understand their closure liabilities and obligations and likely costs and cost estimating processes are generally developed for long-term life-of-mine (asset) planning and budgeting, financial reporting for corporate balance sheet provisioning purposes, and regulator reporting for environmental bonding and financial assurances.These days mining companies need to plan for, prepare and actually mine for closure right from the start of a project. This means that their closure and rehabilitation liabilities throughout each stage of the mine life cycle phases must be understood, planned for, managed and controlled.So how is the industry performing? Understanding of closure liabilities is improving and reflected in liability cost estimations that are recognising the likely issues to be faced at closure, but there is a way to go to ensure that the industry doesn’t add to the increasing legacy liabilities being passed onto the wider community.CITATION:Slight, M and Lacy, H, 2016. Closure liabilities – where are we at?, in Proceedings Life-of-Mine 2016 Conference , pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By E. A. Wieselmann

This chapter presents a successful approach for achieving mine entry stability at the Cane Creek potash mine by the utilization of closure measurements. The mine is located in southeastern Utah (Fig. l). Mining is being conducted at depths in excess of 3000 ft under structurally complex geologic conditions typical of the Paradox salt basin. The closure measurement systems described have definite application for determining relative entry stability in other nonelastic rocks which are similar in behavior to potash. Similar types of closure measurements have been taken in various underground openings throughout the United States, Canada, arid Europe. Application of this closure data has previously met with varying degrees of success as a tool for design of under- ground openings in both elastic and nonelastic media.1-32 Closure measurements can be made easily and economically and they provide a practical solutiori to a practical problem. They are in-situ measurements which do not necessarily require laboratory correlation. Simple closure measurements have special significance in potash because "steady-state" ' closure rate, or creep, of the entries is measured. These closure rates can be utilized because nonelastic media such as potash will never achieve absolute stability around a mine entry. The potash will tend to creep or deform until all entries are closed and the overburden stress is redistributed over what was previously the mine area. The time for this ultimate effect to occur is dependent on a number of mining and geologic variables. Percentage of mine extraction, mining

Jan 1, 1972

By Sean McClenaghan

Significance Setting Size Production Value History of Discovery Zn and Pb at Austin Brook Brunswick Belt Exploration Discovery Hole Geology Structure Metal Zonation Directed Research Incremental Ores Precious metals Closure and Beyond Mining Remnants Tailings

May 1, 2013

By R. C. Ford

The advent of solvent extraction-electrowinning (SX-EW) technology for recovery of copper from low grade oxide ores has extended the operational lives of many historic mines in the western United States, and made many other orebodies economically viable worldwide. Many of these operations are mature and face closure within the next decade, depending on market conditions. Closure of a large copper heap leach operation has not been undertaken, and differs in some important chemical respects from closure of gold leach pads. Challenges for closure include prediction of solution chemistry and draindown characteristics, determining the benefit of cover placement in semi-arid climates and evaluation of solution management strategies once the economics of copper recovery are no longer favorable. This paper discusses issues pertinent to copper heap closure in semi-arid and arid climates, and strategies for their management.

Jan 1, 2000

By M. H. Rauschkolb, J. A. Cremeens

Geotechnical solutions were developed for closure of two historic, remote underground mines in the deserts of southern California. Closure criteria included access closure, minimal site impact, and optimum use of native materials. The closure designs and construction activities incorporated techniques for protecting sensitive biota, particularly bats and desert tortoise. The types of mine openings that were closed include adits, declines, shafts, daylighted stopes, and dugout dwellings. The desert locations permitted implementation of cost-effective closure techniques that relied upon the use of native materials. The strategies and techniques developed for these desert closures are adaptable to other climates.

Jan 1, 2002

By R MacGillivray

The Golden Cross mine was an open-pit and underground gold and silver operation from December 1991 to April 1998. Closure of the mine has been based on an approach agreed among stakeholders. The initial phase was the release of a closure plan which was regarded as the blueprint for the following phases and the closure works required to implement the plan. The second phase involved lodgment of consent applications and their granting for the final water management configuration. The final phase is monitoring, confirmation that the site is performing as required by the closure plan and consents and settlement of final ownership, management and surety arrangements. Industry best practice modelling techniques have been used to finalise closure design and have been shown to be good predictors of site water management and discharge performance. Site discharges are in compliance with toxicology based water quality criteria for the protection of aquatic life and most discharges from the site, including those from the closed cyanide-tailings facility, can now be discharged without further active intervention or treatment.

Jan 1, 2002

By Ximena Massone

Chile is the most important copper producer in the world and the mining sector plays a key value in its economy. However, at present the country does not have a satisfactory set of regulations about closure and restoration of mining operations. In our country many mining operations will, in the near future, shut down their activities, therefore, it is of utmost importance to elaborate and enforce a set of regulations to prevent risks and to protect the environment. The present study is focused on reviewing and analyzing the existing national regulations about the closure of mining operations and preparing a comparative analysis with other international regulations of countries with mining experience. The final results of the study will be a legal proposal to regulate the closure of mining operations in Chile, aiming at minimizing the potential environmental adverse impact, internalizing the social costs by the relevant operators and defining all aspects of liability for the environmental damage.

Jan 1, 1999

By S. Tuttle, R. Sisson

"Suncor Energy Inc. has proposed a 2.2 billion dollar expansion to the current oil sands operation, which will more than double the productive capability of the facility. As part of the application for this expansion, a comprehensive closure plan had to be developed and filed.Closure planning includes a systematic evaluation of the area to be developed, the development activities planned, the goals and objectives of the corporation in re-establishing landforms and ecosystems at the same time as running an effective operation. As early as is practical during the mine development, surface contouring is completed, soil is reconstructed, and vegetation, surface drainage and wetlands are re-established. Once active reclamation is complete and vegetation has been re-established, Suncor monitors maturation of landscapes and ecosystems to provide the submission basis for reclamation certification"

Jan 1, 1999

By K. Adam

Uncontrolled disposal of pyrite wastes and concentrates comprise a major source of acid drainage in active and abandoned sulphide mines. In this paper, the state?of-the-art mitigation measures implemented for the final reclamation and closure of a pyrite concentrate stockpile at Platia Karra, Stratoni mines, Greece, are presented.

Jan 1, 2002

How do you initiate closure planning for a mine site that is on the doorstep of a major community without generating the extremes of panic or complacency? That is the question that is faced by Australia's largest gold mine, the Kalgoorlie Consolidated Gold Mines (KCGM) Super Pit in Kalgoorlie-Boulder. KCGM's Community Relations Manager, Danielle van Kampen, will reveal the lengthy closure planning process that is in train to alert yet not alarm the community about the future of the Super Pit and to generate discussion on issues of importance. What will happen to the 'big hole' that generates both mining and tourism dollars for the City of Kalgoorlie-Boulder as its anticipated closure date of 2021 comes closer? How do you communicate a constantly evolving closure date? Although the process may generate more questions than answers, the project will be discussed at length and with the added benefit of independent community recent research in the form of the public 2009 Closure Consultation and the KCGM 2010 Social Impact Assessment. This is an ABSTRACT ONLY no paper was prepared for this presentation.

Jun 1, 2010