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By John O. Marsden

Technology development has played a crucial role in the minerals industry throughout history. The development of new technology allows mankind to produce metals and minerals at progressively lower cost of production in real terms, and therefore at progressively lower prices, improving their availability, accessibility and utilization worldwide. However, the developers of such technology are not guaranteed to reap the benefits from this effort: There is an expectation that technology developers will gain an advantage over their competitors. Is this a short-term benefit that results from a temporary cost or efficiency improvement, or is it a sustainable longer term "edge" that prevails even after metal or mineral price has been eroded by the implementation of a major step change technology? This issue is examined by reference to several case study examples in the copper industry. BACKGROUND The development and adoption of new technology has played a crucial role in the commodity minerals industry throughout history. As new, cost-efficient technologies are commercialized, the cost of production decreases, and this enables lower grade ore to be processed profitably. This in turn increases the availability and supply of the metal or mineral of interest, and ultimately (in a free market environment where the supply- demand balance determines price) inevitably decreases the metal or mineral price. This leads to the question: Why should mining companies invest in (new) technology development if the result is a decrease in the product price? The answer is to achieve competitive advantage, where the application of new technology enables one or more

Jan 1, 2004

By E. Karampinos, P. Morissette

"INTRODUCTION Ground support is a critical element in maintaining the stability of mining drives in deep and high stress mines. In challenging ground conditions, it is necessary to continuously explore ground support strategies that can control the resulting large deformations. It is an objective of mining operations to optimize the ground support by selecting both appropriate systems and the time of installation of each reinforcement element. A successful ground support strategy will result in the use of a system that ensures both the structural and operational integrity of the excavations and mitigates the need for rehabilitation. Preliminary ground support design is often based on empirical observations and methods. Once a design is implemented, field trials, observations and in situ pull tests are used to fine tune or improve the design. Although not often employed during this process, numerical modelling can provide helpful insights on the impact of different ground support strategies. In this respect, it is possible to explore the use of multiple options before selecting the most promising ground support system for implementation in field trials. The challenges associated with the numerical modelling of rock support for mines have been described by Lorig and Varona (2013) and Potvin (2017). The employed numerical models should capture all potential failure modes of reinforcement over the mining sequence of the excavation. In particular, it is important to emulate the observed in situ ground support performance, as well as the influence of the installation sequence of the support. However, the time and expertise required for this type of modelling of ground support is not often available at mine sites. Even when the expertise is available it requires a major time and commitment of resources to set up, run and calibrate the sophisticated models capable of explicitly capturing the behavior of ground support. Rock reinforcement is an integral part of all ground support systems used in underground mines. Long flexible tendons can reinforce the rock mass deeper into the walls and create a thicker reinforced shell around the underground excavation. This paper focuses on the optimization of the cable bolting strategy in squeezing conditions at the LaRonde Mine by integrating the 3D distinct element method (DEM) in the design process. A calibrated numerical model is used to investigate a series of cable bolt configurations and provide recommendations for the ground support design."

Jan 1, 2018

By J. D. Miller, Jon J. Kellar

Researchers in flotation chemistry have long sought to describe collector adsorption phenomena in greater detail including kinetics, orientation and interactions between adsorbed species. Now a quantitative description can be made in-situ using FTIR internal reflection spectroscopy. Details of the adsorption process at the surface of mineral crystals, machined into internal reflection elements, can be described from first principles, provided the refractive indices, incident angle, and wavelength of light are known. Collector orientation can be established based on spectral characteristics of plane polarized and perpendicular polarized light. Examples of the use of in-situ FTIR internal reflection spectroscopy are given for the sapphire-sodium dodecyl sulfate system and for the fluorite-sodium oleate system. It is expected that quantitative in-situ analysis of collector adsorption reactions by FTIR internal reflection spectro-scopy will continue to grow in importance and will provide an important new dimension in our understanding of flotation chemistry.

Jan 1, 1989

By Gerald L. Tiley

When payloads and hoisting distances are beyond the capacity of a single headrope, a multi-rope hoist will cost less than, and require less maintenance than, several hoists with one headrope per conveyance. This paper describes the basic type of multi-rope drum and friction hoists in use today, the types of ropes available, and the essentials of a satisfactory installation.

Jan 1, 1981

By P. Sander, M. Spiegl, J. Reilly, A. Van Droogenbroeck

Although the outdated idea of calculating risk as the deterministic product of its likelihood and impact is not entirely a thing of the past, a multitude of organizations have adopted the usage of probabilistic methods for risk analysis, as they better reflect the inherent uncertainty of cost and risk estimates with ranges. But are these advancements sufficient in a complex environment such as tunnelling projects, where inadequate modelling of cost and risk can result in estimate discrepancies that run into millions of dollars? This paper explores two advanced probabilistic modelling techniques for tunnelling projects. The first one demonstrates how the cost and schedule uncertainty related to changes in excavation and support classes can be modelled with correlated variables. The second example models the risk related to explosive ordnance clearance on construction sites using a probabilistic event tree.

Dec 1, 2022

By Robert Blair, David L. Fey, Stanley E. Church

Determination of the pre-mining geochemical baseline in bed sediments in watersheds impacted by historical mining activity is important in establishing watershed restoration goals. We have developed methods to solve this problem in the Animas River watershed, southwestern Colorado, using geomorphologic mapping to identify terraces that contain pre-mining sediments. Following a systematic evaluation of possible sites, we collected samples of pre-mining sediments in gravel deposits from 21 sites throughout the watershed. Geochemical analysis of individual layers has produced a chemical stratigraphy that can be tied to the historical record through geochronological and dendochronological studies. Analysis of geochemical data, when coupled with the historical record, clearly shows that there has been a major impact on the geochemistry in bed sediments in the active stream channel by past mining activities. Historical mining has resulted in a substantial increase in metals in the very fine sand to clay-sized component of the bed sediment of the upper Animas River, and Cement and Mineral Creeks, which are the major tributaries of the Animas River. Enrichment factors for metals in modem bed sediments, relative to the pre-mining sediments, range from 1 to 6 for arsenic, 1 to more than 10 for cadmium, 1 to about 15 for copper, 1 to more than 25 for lead, 1 to more than 10 for silver, and 1.6 to more than 12 for zinc. The pre-mining bed sediment geochemical baseline is high relative to average crustal abundance values of many metals. The Animas River watershed above Silverton, Colorado would be readily identified as a highly mineralized area suitable for mineral exploration if it were not disturbed by mining.

Jan 1, 2000

By John Turner, John A. Gibson, David Cass

Contents A. Introduction B. Description of Robbins Company involvement in several of the English Channel Tunnel projects C. Identification of project requirements and comparison of TBM features D. Description of the manufacturers separate roles in the -235 (T-1) TBM E. T-1 performance to January 15, 1989 F. Summary

Jan 1, 1989

By T. L. Brekke, T. R. Howard

Stability of an underground opening can be defined in several ways. To geologists and engineers that are used to working in geological environments where the major parts of the works after careful scaling can be left unsupported during the construction period as well as during operation, any rock mass behavior that requires reinforcement, support or lining may be regarded as a stability problem. To colleagues excavating underground openings in geological environments that require continuous use of reinforcement or support and lining "stability problems" are often associated only with those parts of the work where "standard" construction procedure and method of reinforcement or support and lining is inadequate, and special measures therefore needed. In either case, a major objective is to assess the stability problems correctly -as far as possible at the planning stage -- and choose methods for excavation and reinforcement or support that will bring the opening safely and as economical as possible through the problem areas. INTRODUCTION It is not uncommon that stability problems associated with faults or seams have been described as "unexpected." This term has unfortunately been used to indicate that no one knew that the fault or seam existed prior to excavation. A careful review of documented cases where serious stability problems have occurred revealed that the existence of these zones most often was known, but that their behavior was incorrectly assessed prior to or during construction. Miscalculations have been made in terms of the type and magnitude of loads that developed, and in particular in terms of the time-dependant behavior.

Jan 1, 1997

By S. K. Kawatra, R. A. Seitz

Nonpolar hydrocarbon oils are commonly used in the flotation of minerals to fulfill a number of roles. These roles include reducing overall reagent costs by replacing part of the collector addition, improving coarse particle recovery without reducing selectivity, as well as several others. This paper will cover the types of oils which are available, their physical and chemical characteristics, and the effect of these characteristics on the function of hydrocarbon oils in flotation. In addition, techniques for improving the behavior of oils will be discussed.

Jan 1, 1986

Since 1955 Gaspe Mines has produced 144 million tonnes of ore, averaging 0.87% Cu, mined from two open pits and underground workings. In 1994, four exploration drill holes discovered a buried porphyry/skarn Cu-Mo deposit at depths of between 1000 m and 1700 m below the top of Porphyry Mountain. The mineralization and alteration associated with the Porphyry mountain quartz monzonite does not outcrop. A total of 19,500 m of drilling in 12 drill holes has outlined 200 million tonnes grading 0.73% Cu and 0.08% Mo. Mineralization occurs as veins and disseminations of chalcopyrite and molybdenite. Drilling and feasibility studies continue.

Jan 1, 1998

By K. J. Sollman

As a class, silicate minerals have likely found the broadest, if not largest volume, use in combination with polymeric binders of all industrial minerals. Among the silicates, calcium metasilicate, wollastonite, enjoys a front runner position in a near universal sense. It is a viable and desirable part of composites ranging from thin films to large moldings; from a common filler/extender for paint for your garage to a reinforcement for the exterior surfaces of a luxury vehicle affordable to very few. This article is focused upon the variations in particle morphology and the surface characteristics which, by way of commercial examples and discussion of active research programs, make this environmentally benign mineral so unique.

Jan 1, 1993

By R. L. Kloberdanz

Peruvian legislation requires the preparation of an Environmental Impact Study (EIS) for new and expanding mines/beneficiation facilities and the preparation and implementation of an Environmental Adjustment and Management Program (PAMA) to control and mitigate environmental impacts associated with existing mining/beneficiation activities. Shepherd Miller, Inc., developed guidance documents for preparing an EIS and PAMA for Peru's Ministry of Energy and Mines and presented workshops to Peru's mining industry on preparing an EIS and PAMA. This paper discusses the process and approach taken and the results.

Jan 1, 1998

By E. J. Miller

The Ventilation Branch is engaged in a project to determine if low level carbon monoxide monitors used for early detection and warning of fire in a coal mine conveyor belt entry can provide protection equivalent to that of thermally actuated point type heat sensors commonly used for fire detection. A series of tests were conducted to determine the required operating parameters, such as sensor spacing and alarm levels of detected carbon monoxide to provide equivalency between' these methods of fire detection. This report summarizes the results of these tests.

Jan 1, 1980

By L. P. James

The Bulagidun copper-gold system occurs in Tertiary andesitic volcanic rocks. It is located (figure 1, from Curless, 1991) ca. two days walk from the coast in an isolated area on the northerly slope of the main range of mountains, in steep terrain dissected by erosion. Detailed and district-scale exploration from 1988 to 1991 by BHP Minerals defined a small, sub-economic resource of gold and copper. One preliminary estimate of the resource in bedrock suggests 14.4 million tons at 0.68 grams / Tonne Au and 0.61% Cu, in multiple small bodies.

Jan 1, 1993

By Euler De Souza, Jason Chew, Aldrich Philip Dirige

Sillmats are structural elements upon which the safety and economics of underfill mining or sill pillar recovery in stopes of moderate width with steeply dipping ore zones, depend. The traditional stability design of cemented sillmats appears to have developed from experience and from standard static physical model tests such as uniaxial and triaxial compression. Such standard static physical model testing approach arrives at some approximate parameters, normally used to describe or predict the behaviour of sillmats in analytical or numerical models. This approach offers inherent limitations and generally results in conservative designs. Centrifuge modeling studies are combined with numerical modeling in this paper to provide insights into sillmat strength behaviour. The results of both modeling techniques suggest that, in stopes with smooth rock wall conditions, sillmat failure is driven by the fill self-weight and has minimum dependency on the fill binder content. In stopes with rough rock wall conditions, however, the wall roughness contributes significantly to the stability of the sillmat during underfill mining. This study indicates that the stability of paste fill sillmats can be designed with confidence using centrifuge physical modeling in combination with numerical modeling.

Jan 1, 2001

By K. V. K. Prasad

Solution of most engineering problems requires, in addition to vast numerical calculations, substantial use of practical judgement and expertise. With advances in applied mathematics and computer technology, the numerical aspects of problem solution have reached a considerable level of maturity. However, it is only recently that approaches like the expert systems methodology have been developed to incorporate the judgemental aspects as well. For rapid development and prototying of expert systems, expert system building tools or "shells" have become widely available. For the expert system developer, identification of the key characteristics of the problem domain and selection of the right expert system tool are of crucial importance. In this paper, the important attributes required in an expert system shell for use in the development of a mine ventilation planning expert system are discussed. These attributes are general in that most engineering problems in mining would have these requirements. Also, the results of an exercise undertaken to evaluate commercially available shells for application to mining engineering problems are presented.

Jan 1, 1989

By M. G. Rylatt

The Ekati process plant flowsheet features the common steps in diamond recovery plant design. Primary treatment and concentration is by crushing, scrubbing, high-pressure grinding rolls and heavy medium separation (Fig. 1). Secondary concentration is by an attrition mill; wet, high-intensity magnetic separation and X-ray sorting (Fig. 2). All of these are performed on site, although final sorting of the diamonds into commercial categories will be carried out elsewhere. The initial throughput rate is 9 kt/d (9,900 stpd), increasing to 18 kt/d (20,000 stpd) during the first 10 years of operation. A range of ore characteristics will be encountered that will effect the plant operating conditions during the life of the mine. The adopted design envelope is based on these expected variations. The design is based on the use of large-scale equipment, incorporating the latest and most efficient technology available. Where proven technology exists, no attempt was made to reinvent the wheel. However, where recently developed technology offers a significant advantage, this has been incorporated into the design. The Ekati run-of-mine (ROM) and coarse ore handling facilities are unheated, to take advantage of the better handling characteristics of the frozen ore in winter. The stockpile reclaim features an MMD mineral sizer (a toothed roll crusher) to minimize the problems of handling thawed, sticky kimberlite in the summer and break frozen lumps in the winter. All processing downstream from primary crushing and the coarse ore stockpile is carried out in a temperature-controlled environment in the main process plant building. Personnel involvement in the process is mini¬mized by using a Modicon Quantum series PLC with human-machine-interfaces (HMI) running Wonder-ware software on dedicated personal computers.

Jan 1, 1999

By Jerry Dollinger, Levent Ozdemir

An extensive series of laboratory cutting tests using linear and rotary cutting machines were carried out with the objective of investigating the feasibility of achieving very high rates of penetration with TBMs in rocks of low to medium strength. These tests were performed with large diameter disc cuttrs at cutter path spacings and penetrations of up to 12 and 1.75 inches, respectively. A predictor model was also formulated to characterize rock cutting at large spacings and penetrations.

Jan 1, 1987

By Craig M. Sams

Dry grinding circuits and factors influencing the selection of the most appropriate grinding system for a given ore selection are discussed. Comparisons of the drying, grindability, installed costs and operating costs are presented for several grinding systems.

Jan 1, 1994

By Jeff Hussey

Since 1955, Gaspe Mines has produced 150 Mt (165 million st) of ore averaging 0.9% copper. The ore was mined from two open pits and from underground workings. In 1994, four exploration drill holes discovered a buried porphyry/skarn copper-molybdenum (Cu-Mo) deposit at depths of between 1,000 and 1,700 m (3,280 and 5,580 ft) below the top of Porphyry Mountain. The mineralization and alteration associated with the Porphyry Mountain quartz monzonite does not outcrop. Prior to 1997, about 19,500 m (64,000 ft) of drilling in 12 drill holes had outlined 200 Mt (220 million st) grading 0.73% Cu and 0.08% Mo. Mineralization occurs as veins and disseminations of chalcopyrite and molybdenite.

Jan 1, 1998