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Between 1993 and 2003, a series of AG and SAG mill pilot plant trials were conducted using Hardinge Ical pilot plant scale SAG mills on numerous ore samples and ranging across a wide variety of operating conditions. The data from these tests were used to evaluate the design of SAG and AG mill circuits for over a dozen projects, of which about half were eventually constructed and commissioned. The data were also used in the development of SAG mill modelling, scale-up and simulation procedures by several consultants who had access to part of the data set. Recently, we have had the opportunity to bring this data together and further analyse the consolidated dataset. This paper reports on the outcomes of this analysis that has identified the impacts of different AG/SAG circuit flowsheets and operating conditions on energy efficiency and operating cost.

Jan 1, 2012

Operating and Social Considerations from a Contractor?s Perspective

May 1, 2013

By G. W. Poling

"Construction, equipping and planned operation of a new laboratory for engineering-teaching and research in coal and mineral processing is described. This facility will provide approximately 1860 m2 (20,000 ft. 2 ) of laboratory space with nearly half devoted to a new venture in coal preparation. Two high-bay, overhead crane-accessed areas will accommodate major unit operations for each of the ""coal"" and ""mineral"" laboratories. COAL PREPARATION FACILITIES:The coal facility provides three main functional areas:(1) Sample preparation (drying, blending, crushing, screening) and sink-float washability testing.(2) Unit operations U1igh-bay, serviced by crane).(3) Analytical laboratories.(l) Sample Preparation and Sink-Float TestingBreaking or comminution of coal will be accomplished using a rolls crusher, a hammer mill, a jaw crusher, or a pulverizer. Capacity to prepare coal at rates of up to approximately 4 tph will be provided by some of these units. Large diameter (~0.5m) baths of heavy organic liquids will be available for sink-float washability tests on coal samples of several kg. Particle sizes of up to 25 mm can be tested in these baths. Smaller scale washability tests on finer samples will be accelerated by centrifuges."

Jan 1, 1980

By Joseph Sawicz

By now, the concept of remotely controlling heavy equipment in underground mines has become commonplace. Personnel safety is the biggest justifier for remote control, followed by an inherent cost saving (in certain cases) when wireless video is added to the mix. There are a handful of vendors targeting this need, and for years the mines have remained loyal to their brand. But as the number of remote-control related accidents and maintenance costs increase it forces our industry to take another look at this commonplace concept. And as the blinders are taken off, the mines are getting the revelation that not all remote control systems were created equally. This paper highlights the differences between various remote control systems, and then moves into an in-depth look at HARD-LINE?s package which drastically cuts maintenance costs, and also provides a solid investment toward full Tele-operation.

Apr 1, 2005

By Fred C. Delabbio

The successful implementation of a new technology in an underground production mine requires many challenges to be overcome. These challenges include mine hardening of new technology, mitigation of safety risks and hazards, mine operation support, and technology transfer to mine staff. In the end, the majority of these challenges relate to the human aspects of implementation. The approach selected to overcome these challenges must be customized and appropriate for each unique situation. This paper outlines the approach used to address these challenges as part of successful implementation and resulting demonstration of the hydrogen fuel cell locomotive at the Placer Dome (CLA) Limited, Campbell Mine. This technology demonstration at Campbell Mine is critical for determining technical, regulatory and implementation aspects to be incorporated into future fuel cell prototypes such as the LHD project.

May 1, 2003

By Warwick D. Bullen

Gold mining in the Yellowknife area of the Northwest Territories started long before the concept of sustainability entered the academic literature and by the time the term enjoyed widespread public acceptance, the Yellowknife gold mining industry was in its sunset years. Nevertheless, the city of Yellowknife will long outlive the gold mines that it was founded on, demonstrating that not only can mining build sustainable communities, but that sustainable mining as a concept is an entirely valid precept. To this effect, the authors examine the complex economic and social aspects of the gold mining industry in the Yellowknife area over the last 70 years.

May 1, 2004

By Michael J. Lawrence

"The VALMIN Code was developed and formally adopted by The Australasian Institute of Mining and Metallurgy (AusIMM) in 1995 and a revision was issued in 1998. The VALMIN Code applies to all relevant reports under the Australian Corporations Law, including submissions to the Australian Stock Exchange (ASX) and the Australian Securities and Investments Commission (ASIC).The VALMIN Code and Guidelines sets standards for the preparation and commissioning of independent assessment and/or valuation reports on mineral and petroleum assets or mineral and petroleum securities.It is mandatory for AusllvI:M's members to follow this Code in these relevant circumstances and failure to do so will result in serious sanction of the member by the Ausllvllvfs Ethics Committee. Public support for the use of this Code has been given by regulators (ASX/ASIC) and market participants ( eg major accountancy firms). It is also endorsed as a guide to general best practice in project assessment and valuation.This paper will discuss how the VALMIN Code has worked in practice over the past few years. It will also examine areas where the Code could be improved and how it could form the basis of a new Canadian Code for mineral property valuation."

Jan 1, 2003

By Shanjun Mao

This paper summarizes current achievements of Digital Mining in China, puts forward the concept, framework and key technology of Smarter Mining, and finally points out that there is still a long way to go in order to acheive Smarter mining.

Aug 1, 2013

By Denis Beaudoin

Program Basics: Goals, Course Content & Training Process Sudbury: History of the Program & Lessons Learned Diavik: History of the Program & Lessons Learned Most Recent Program: Totten Mine in partnership with Sagamok Anishnabek Summary -Lessons Learned Conclusion

Oct 1, 2010

By C. H. B. Leitch

"The Bralorne-Pioneer deposit produced more gold than any other deposit in British Columbia over its 70 years of operation (130 kg or 4 million oz of Au, from 7 million tonnes of 18 glt ore). Mineralization is related to a suite of late Cretaceous albitite dykes of 85 to 90 Ma age. It thus occurred long after and is genetically unrelated to the Early Permian (275 Ma) Bralorne diorite and soda granite.The major veins strike about 110 degrees and dip north at 70 degrees, with slickensides plunging 45 degrees east that indicate last movement was reverse. Major ore shoots in the veins occupy somewhat less than 20% of the vein and plunge steeply west, roughly perpendicular to the slickensides. The structures that contain the veins probably formed at around 95 to 90 Ma during a strike-slip episode with easterly directed maximum compression.Disseminated pyrite, pyrrhotite, and minor chalcopyrite occur within envelopes up to several metres from the veins. Arsenopyrite is confined to vein selvages. Local sphalerite and galena appear to correlate with gold-rich portions of the veins. Traces of tetrahedrite and stibnite have been observed but tellurides have not. Gold is found principally as thin smeared flakes of the native metal in the black sulphidic septae of the strongly ribboned veins. Hydrothermal alteration envelopes around the veins grade outwards from intensely foliated quartz - ankerite - sercite (±fuchsite) to less sheared calcite - chlorite - albite to unsheared epidote -calcite.Open-space vein filling textures found in the deep (mesothermal) environment at Bralorne can be explained by a fault- valve model. High-angle reverse faults may have acted as fluid-pressure activated valves on geopressured reservoirs, causing large cyclic fluctuations in fluid pressure that promoted mineral deposition in an episodic fashion . The faults that were mineralized were reactivated sub-vertical former strike slip faults, oriented at a high angle to the northeast-directed stress in a compressive regime."

Jan 1, 1990

By M. Wu, G. Plascencia, A. E. M. Warner, A. Vahed, T. A. Utigard

Nickel oxide granules formed by pyrohydrolysis of a chloride solution, were reduced in hydrogen. Below 400 °C, an incubation period was observed, followed by very slow reduction. In the temperature range from 400 to 600 °C, the rate of reduction increased with increasing temperature and increasing hydrogen pressure. Microscopic analysis showed that in this temperature range the reaction followed the shrinking core model. Above 600 °C, the reduction rate decreased noticeably before suddenly becoming very fast at and above 950 °C. Microscopy showed inner bands of metallization inside the outer metallic rim, indicating partial blockage of the interface between the reacted and un-reacted NiO core. At these temperatures, particle agglomeration and sintering were also found to take place. Surface segregation of sulphur may account for the slow down in reduction rate above 600 °C. From an industrial point of view, reduction should be carried out from 550 to 600 °C with as high a concentration of hydrogen as possible. If sintering and agglomeration are not of any concerns, reduction can be carried extremely fast at about 1000 °C.

Jan 1, 2005

By S. Heusermann, S. Fahland, J. Behlau, A. Schäfers, J. Hammer

In the course of the deep subsurface use, the Federal Institute for Geosciences and Natural Resources has been carrying out extensive geological and geomechanical research and practical project work on domal salt structures, to prove their suitability e.g. for the disposal of radioactive wastes. Recent work on disposal sites has been taking into account the 3-D geological and geomechanical modelling of the underground structures. The geological models are generated using the special-construction openGEOTM code to improve the visualisation and interpretation of the geological data basis, e.g. borehole, mine, and geophysical data. For the geomechanical analysis of underground structures the JIFE finite-element tool has being developed to analyze large 3-D structures and to consider coupled THMC processes. The results of finite-element calculations, i.e. stresses, strains, displacements, and dilatant zones, are basic values for the evaluation of the stability of the structures and the long-term integrity of the geological barrier. As an example, the results of geological and geomechanical investigations of the Morsleben repository are presented including three-dimensional modelling of the entire geological structure of the central part of the mine as well as three-dimensional geomechanical model calculations to provide the necessary results for a long-term safety prediction.

Jan 1, 2015

By S. A. Ghoreishi-Madiseh

Underground mines, with their relatively high ground temperature and their extensive backfilled stopes provide a great opportunity for producing geothermal heat. The novel idea of installing a network of heat exchange tubes into stopes prior to backfill placement converts each mine stope into a heat producing battery. In this system, backfill plays the role of the heat exchange medium conducting heat from the surrounding rockwalls to the heat exchange tubes. This geothermal heat can be used for heating: mine facilities and buildings, the intake air, a close-by mineral processing plant, or even nearby communities. This paper investigates the possibility of extracting renewable geothermal energy from backfilled mine stopes by means of closed-loop geothermal cycles. To simulate realistic operational conditions a heat transfer model is developed and solved numerically. To evaluate the numerical results, a small scale physical model is constructed and the experimental results are compared with the simulation results. The study estimates the sustainable rate at which heat can be extracted from a typical underground mine stope, the resulting outlet temperature and performance of the geothermal system. The results show that mine stopes are capable of sustainably producing geothermal heat not only when the mine is active, but also after the depletion of the ore body. Therefore, an underground mine will no longer be perceived as an enduring economic liability, but as a long-lasting source of clean, renewable, and inexpensive low-grade geothermal heat.

Aug 1, 2013

By Helmut Ehnes

Over 330 million accidents at work happen world wide every year, only counting those leading to more than four days absence. More than 350,000 end fatal. Two million people more die every year due to work-related diseases. To sum this up: around 2.4 million people die every year because of work conditions. Among many risky industries, mining stands out. While mining represents just 1% of employees globally, it unfortunately represents 8% of all occupational fatalities. Mining operations go along with a variety of hazards. Not only in large operations, as they first come to mind, but also in the manifold small scale mines, with an estimated 13 million labourers worldwide exposed to substances such as dust, mercury and other chemicals, while also dealing with poor ventilation, inadequate space and overexertion. But is the number of severe accidents and diseases inevitable or can we change this situation? We can make mining sustainably safer, but we need a successful strategy to do so. A high potential lies in Vision Zero. Vision Zero is a prevention strategy for a safe future without fatal or serious occupational diseases, work accidents and traffic accidents. First defined as early as in the 19th century by Eleuthère Irénée du Pont, its very successful elements were adopted by many European countries first aiming at road safety, then extended to safety and health at work. Vision Zero?s holistic elements cover technology, workplaces, rules, and people as fields of action. By focussing on severe and fatal accidents, its application increases the level of safety and health overall.

Aug 1, 2013

By Ellis Thomson

The microscope is now used extensively not only in the examination of solid ore but also in the determination of fragmental mill products. It has therefore become a matter of paramount importance to be able to mount and polish fragmental as well as solid specimens in the easiest and most efficient way, so that the minerals present may be readily determined. In the case of the solid ore the ordinary mount of plasticine set on a glass or metal slide serves for most practical purposes. An improvement on this is furnished by the small brass container inside of which the specimen is mounted in a cementing medium of sealing wax. The latter is the method in use at Harvard University. It has the advantage of uniform height, thus obviating the necessity of a slide of any sort. It is also easily catalogued as the brass holder may be stamped with a convenient series of letters and numbers that will serve as a label. Other advantages of this type are the ease with which any particular part of the section may be re-located, the excellent storing facilities afforded by mounts of uniform size, and the possibility of polishing ten or a dozen sections at the same time by means of a holder which is placed over the polishing wheel, is geared with it, but revolves the opposite way.

Jan 1, 1926

By André Piché

"Over the last ten years, several developments have been undertaken to conceive a machine capable of carrying out simultaneously all the mining tasks in hard rock deposits: cutting, mucking, hauling, ground support and dust control.The main advantages of continuous mining over conventional drill and blast is the elimination of the cyclical nature of the actual methods. Other advantages sought are improved stability of mine openings, higher productivity, lower costs, and a cleaner and safer mining environment. Noranda has con-tributed to these developments in a major way. As a member of HDRK, Noranda participated in the development of two mechanical continuous mining machines; the TM60 and the Wirth. Noranda also undertook a development of its own based on the utilization of electricity to break rock. This technology is called plasma blasting (PBT). The concept of plasma blasting is illustrated in Figure 1.When the operating voltage is reached (18kV), the energy is released through a high current switch (500k A) into a coaxial powercable. It is then delivered to the tip of an electrode inserted into a drill hole which is filled with an electrolyte (water). When the energy reaches the electrolyte, it is instantaneously transformed into a high temperature, high pres-sure plasma that produces a shock wave capable of breaking rock(1).After initial testing of the plasma blasting technology in the lab and in the feld, two experimental platforms were constructed. The first one, a test bench, was erected at the Noranda Technology Centre in Pointe Claire, Quebec.(2)The second one is a rock breaker prototype based on a standard diesel-powered carrier (Fig. 2). Each platform was equipped with a 300 kJ pulsed-power module.In 1993, the rock breaker prototype was used for an extensive series of tests in the field. During that campaign, over 700 oversized boulders were blasted. The results of the tests demonstrated that more durable components for PBT were needed. The test bench was then used to successfully develop and test long-lasting components (probe, switch, cable, connector) that can be adapted to industrial platforms leading to the commercialization of the technology."

Jan 1, 1996

By M. Noaparast, N. Nickoletopoulos, André R. Laplante

"This paper presents an application of the use of synthetic ores to study gold recovery by gravity. Three case studies are presented: the first focuses on the use of tungsten to study applications of Knelson Concentrators for upgrading gravity concentrates; the second on tungsten again, in this case to study the performance of a 86 Falcon Concentrator; and the third on lead to mimic gold's grinding behaviour.It is shown that the use of synthetic ores with metallic substitute for gold is not only expedient, but it can also lead to an increased understanding of separation and grinding mechanisms, because of the more accurate results and controlled particle shapes. The case studies highlight the problems associated with gold particle flakiness and gangue density. The grinding behaviour of malleable materials is shown to be complex, as particles can migrate to coarser size classes by flattening and cold welding, and to finer size classes by folding and actual breakage.IntroductionThe title of this contribution is not entirely misleading. Mineral processing has much to do with philosophy, rather Philosophy, as described by Georgius Agricola:""Furthermore, there are many arts and sciences of which the miner should not be ignorant. First there is Philosophy, that he may discern the origin, cause, and nature of subterranean things; for then he will be able to dig out the veins easily and advantageously, and to obtain more abundant results from his mining. ""1"

Jan 1, 1995

By Karl J. C. Harries

"6.1. INTRODUCTIONThis chapter comments on some of the more common types of agreements related to property examination and acquisition, other than the farm-in/joint venture agreement or common undertaking, which is dealt with in the next two chapters. Many of the comments made in Part IV of Chapter 4 apply equally to any such agreement. In addition, many of the comments in Chapter 8 and the examples in Volume II are most certainly relevant to many other types of agreement.6.2. RIGHTS OF FIRST REFUSAL1A right of first refusal is a right that obligates an owner to offer his property, or an interest therein, to the holder of the first right if the owner intends to sell or otherwise dispose of it. It may be triggered either by the owner wishing to offer his property for sale or by receipt of a bona fide offer to purchase his interest from an “outside” third party. The mechanics and procedures to implement a first right should be set out clearly in the agreement, and their basics are the same, whether the first right is a stand-alone document or is part of an acquisition agreement.2Rights of first refusal are common in agreements to permit some control over the disposition of an interest and there they can be a valuable provision. However, some explorationists feel that they are also a good stand-alone agreement to have while a property is being evaluated to decide whether or not it is worth optioning. The reasoning is that such an arrangement will tie up the property to allow a quick look and, if the property looks interesting, the balance of the term of the first right will give an ample exclusive period of time to negotiate with the owner and settle an acquisition agreement. In addition, the explorationist is protected by the first right if the owner decides to negotiate a deal with another party."

Jan 1, 2003

By Philip J. Bangerter, Chris Twigge-Molecey

Design for safety is critical to metallurgical plants, due to the inherently dangerous nature of their processes. Two significant areas of concern are: 1. preventing catastrophic process failures that cause damage or injury; and 2. operational safety that directly affects those working in or living near the plant. Process safety involves human behaviour, but the designer can eliminate or control hazards by engineering approaches, and control impacts through the design of the operating procedures. The tools available to guide safe facility design include bowtie analysis, hazard analysis, and hazard and operability studies. Clean plant design principles can guide the design process to address in-plant occupational health and safety issues. Auditing and review is a key part of the overall design process.

Jan 1, 2015

By Corinne Boone

CO2e.com, LLC - launched in November 2000 - aims to be ?the global hub for carbon commerce.? CO2e.com is a subsidiary of the Cantor Fitzgerald Group, one of the world?s leading brokerage firms Recent Investor in CO2e ? Mitsui & Co. Alliance with Cantor Fitzgerald Environmental Brokerage Services Group (CFEBS) Offices in London, Toronto, Tokyo, New York, San Francisco, Los Angeles, Connecticut, Houston Primary Goals/Benefits of ET § Goals of Emissions Trading: ? Permit Industrial Growth/Expansion ? Promote Economic Efficiency and Flexibility in Meeting Air Pollution Standards § Benefits of Emissions Trading: ? Enhance Air Quality w/o Economic Stagnation ? Encourage Development of New Technology ? Foster Most Efficient Use of a Limited Resource -- Clean Air § Contributes to Sustainable Development and objectives of UNFCCC, Kyoto Protocol?.

Nov 1, 2002