Search Documents

By Robert B. Parsons

"The budget that was tabled by Finance Minister MacEachen on November 12, 1981 will result in a major tax reform of Canada's income and sales tax systems, the likes of which have not been witnessed by taxpayers since 1971. All segments of the economy will be affected one way or another by the far-reaching budget proposals; the mining industry did not escape untouched.Important changes will be introduced which will alter some of the fundamentals of structuring mineral resource ventures in Canada. This month, Tax Notes examines these changes, and also summarizes the other highlights of this key federal budget.IntroductionFinance Minister MacEachen's budget, with its lower personal tax rates, loophole plugging and tax shelter bashing, represents the biggest shakeup in our tax system since tax reform in 1971. In his budget, presented in the House of Commons on November 12, Mr. MacEachen proposed substantially lower tax rates for middle and upper income individuals, with the top federal and provincial tax rate dropping to about 50%, but in return he eliminated most of the opportunities for individuals, and corporations, to reduce or defer taxes through a wide variety of tax shelter and tax planning mechanisms.Although many of those budget proposals that dealt with the resource industries focused on the implementation of the September 1, 1981 agreement reached by the federal and Alberta governments concerning the National Energy Program (see Tax Notes in the December 1981 issue of the Bulletin), the budget also contained some proposed amendments that would have significant implications for investment in the mining industry.This month, Tax Notes examines these latter proposals, and also summarizes very briefly those budget proposals which are not unique to the resource sector."

Jan 1, 1982

By Bennett McLaughlin, Gille Brousseau, John F. Cook

"La Mine Bousquet commenced operations in October 1979. Mining has been by underground methods from two main zones which dip steeply to the south , Sub-level stoping methods with following fill are used.The orebody and immediate country rocks are sericitic and highly schistose. The intensity of schistosity varies significantly and poor ground conditions prevail, especially within the orebody,Initially few mining problems were encountered but in May 1981, significant damage occurred. A system of stabilizing pillars was introduced with improved support systems. Predevelopment in ore and pre-drilling of blastholes were reduced with extra footwall development.Damage has continued to occur on a regular basis particularly during the spring thaw. Generally, the adverse conditions have been successfully overcome.IntroductionMost of the mining problems that have been experienced at Bousquet have been caused by poor ground conditions . This pa per describes these conditions, considers the cause and describes the ways in which the conditions have been dealt with . Despite the problems, Bousquet is a successful operation which in 1983 produced 95,000 ozs of gold from 514,000 tons of ore."

Jan 1, 1985

By L. H. Rajala, K. H. Singh

"This paper presents the results of a detailed feasibility study carried out to investigate whether a low-grade deep underground mine of Falconbridge Nickel Mines Ltd., closed since 1975, could be made more productive and profitable by the introduction of new mining technology. For this purpose, recent advances in mine design and development concepts, larger and better designed machines, such as hydraulic drills, high-pressure down-the-hole machines, LHDs, new blasting concepts, more efficient and improved stoping methods, and ground control technology were considered. Technical and economic analyses incorporated the latest computer-based techniques. The mine was reopened in 1979 and the paper concludes with an assessment of actual progress and performance compared with that planned and forecast.IntroductionThe East Mine orebody, located between the Falconbridge Mine and Inco's Cryderman Mine in the Sudbury District of Ontario, has been in production since 1956. From 1956 to 1978, about 5.6 million tons of ore had been mined from this ore zone. The ore body is low grade and was developed as a cut-and-fill operation. Due to high operating costs, the mine has been shut down several times during economic downturns. The latest closure was in 1975 due to a lower demand for metal.In 1978, investigations were initiated to assess the economic and technical feasibility of mining this ore using new developments in mining technology. In this study, consideration was given to the application of bulk mining methods with a potential for higher productivity, trackless development utilizing efficient LHD machines and hydraulic drills, new blasting and fragmentation concepts, and new ground control technology. Advanced computer techniques, such as finite element, for mine design and rate of return with discounted cash flow analyses for the economic comparison- of various mining options were utilized for a rapid and comprehensive assessment during the feasibility stage."

Jan 1, 1981

By G. Yan

The gas diffusion layer (GDL) is one of the most critical components of the proton exchange membrane fuel cell (PEMFC) in achieving good performance. The GDL serves as a current collector, transport media for fuel and oxidant to the catalyst layers, a support for the catalyst layer and a medium for water management. In this paper, we will discuss the modeling and experimental measurement of the reactant distribution in the GDL and to the catalyst layer. This will be done for some new and advanced engineered GDLs. Novel optical technique which correlates measured data with reactant distribution are used. This technique combined with modeling allows optimal design of engineered GDLs.

Jan 1, 2005

By Kristie D. Tarr

Ideally, in situ monitoring would supply the input data for numerical modeling of backfill material property requirements. However, clue to production requirements and costs of conducting field tests, input data are often based on small-scale laboratory tests. The size of test samples is known to play an important role in the laboratory assessment of the behaviour of geotechnical materials, including backfill. There are observed differences between the mechanical properties of laboratory-scale samples and those of in situ materials, and these are generally attributed to the differences in scale. Various scaling factors have been proposed for converting laboratory observations to anticipated in situ conditions for soil and rock materials. With regard to mine backfill, very limited studies exist which have involved the effects of sample size on material properties. The literature indicates that reported backfill strength data are based on a variety of test sample sizes and in some cases, specimen geometries. Carefully determined laboratory scale effects could play an important role in estimating the potential backfill behaviour in the field, especially when developing new backfill systems. Laboratory studies were conducted with sample diameters ranging from 50 to 300 mm. Scale factors relating specimen size to strength were developed wherever possible, and are presented in this paper

May 1, 2008

By Robert B. Parsons

"Finance Minister Paul Martin's first budget disappointed almost everyone. The business sector was disappointed at the some what feeble attempt to grapple with the country's deficit. The mining industry was disappointed by tax proposals regarding mine reclamation that fall short of the industry's needs. Has anybody been happy with a federal budget? Federal Budget DisappointsThe federal government's budget papers that were tabled on February 22, 1994, contained a rather bizarre mixture of unrelated tax proposals. The budget signals an unexpected attack on the tax treatment of debt settlements, on certain types of corporate reorgani2ations, and on income earned by foreign affiliates. This is an old style budget, which proposes a pot pourri of technical changes and policy initiatives. Mine ReclamationEffective February 23, 1994, a taxpayer's contributions to a prescribed mine reclamation trust fund will be deductible as a current expense. The budget papers do not provide a definition of what will constitute a ""prescribed"" trust: this definition will surface in due course. However, the budget papers indicate that:• income earned in such trusts will be subject to tax each year;• all withdrawals from the trust (including income already taxed) will be included in computing the income for tax purposes of the recipient;• reclamation costs will continue to be fully deductible at the time incurred; and • contributions, trust earnings, and withdrawals will not be taken into account for the purposes of determining a taxpayer's resource allowance."

Jan 1, 1994

By J. S. Redpath

Eighty feet of overburden, thirty feet consisting of fine, water-bearing sands, was encountered during the construction of a shaft collar for Chimo Gold Mines Limited at its Louvicourt, Quebec, property. This paper describes the excavation and construction methods used on the project. Open-cut methods, a sheet pile cofferdam, chemical grouting and special blasting methods were used during excavation. Concrete placement was hampered in the lower portion by a heavy water flow, and aided in the upper portion by an unusual method of form bracing. Plant and • pum11ing facilities are also described.

Jan 1, 1966

By L. Bichler, C. J. Verdon

In this work, the effect of doping yttria stabilized zirconia (YSZ) with 5, 10 and 15 mol% erbium oxide (Er2O3, erbia) was investigated using spark plasma sintering (SPS) technique. Sintering was carried out at 1300°C with 30 and 60MPa uniaxial pressures and a 5min hold time. Densification kinetics were studied using displacement response from the SPS machine. As-sintered microstructure characterization was carried out via scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, while chemical composition was characterized by energy dispersive X-ray spectroscopy (EDS). The results suggest that sintering carried out at 60MPa produced high density composites even though erbia dopants were found to inhibit material densification and grain growth during sintering. 5, 10 and 15mol% erbia- YSZ had cubic crystal structures, as verified by XRD analysis.

Jan 1, 2014

By P. R. A. Andrews

"Talc ore from Bakertalc, High water, Quebec analyzing about 60% talc, previously dry ground to about 95% minus 53 µm was beneficiated in an 11.4 kg/ h pilot-plant flotation circuit. A concentrate of 95.9% talc (necessary for paper-grade) was obtained at a recovery at 75.3% by employing 53 g/t of Dowfroth 250 collector at pH 9.2; further cleaning increased the grade to 97.2% talc at a recovery of 57.5%.Flotation of fresh ground 60% minus 44 µm ore at a feed rate of 18.6 kg/ h produced a grade of 96.4% talc with a recovery of 78.2%, using Aerofroth 70 collector a six carbon-branch chain alcohol, at pH 9.2.The similarity in the concentrate grade and recovery between pre-ground and fresh-ground ore indicated that it was not neces¬sary to grind to 95% minus 53/2m to achieve comparable selectivity. A grind of 60% minus 44 pm corresponds to 100% minus 300 µm.Flotation retention times obtained with fresh ground ore indicate 33 min. for combined rougher/scavenger, and 15 min. each for the first and second cleaners.Talc-magnesite flotation separation is explained in terms of physico-chemical forces, with reference to surface charge and adsorption mechanisms."

Jan 1, 1989

By M. A. Kelly

Pit Optimisation using the Lerchs Grossman algorithm has been successfully applied in many deposits. Pit shells often form the basis for scheduling. Pre-assigned costs may not accurately reflect the costs that strategic scheduling decisions are based on. This can affect all mines, but is particularly true for commodities requiring blending. Adoption of Maximiser technology addresses these cost based scheduling and blending challenges.

May 1, 2007

By Tim Gartner

This paper introduces a new application of a proven technology to provide dynamic, voltage regulation in underground mine electrical distribution systems. This technology acts to ?stiffen? the electrical power feeding continuous miners and generally raise and improve the voltage regulation at the continuous mining machines which may be located over long cable distances from the mine incoming electrical substation. This is extremely valuable for large underground continuous mining operations that use high power electrical mining machines fed over very long cable lengths (measured in 10s of km, from mine shaft to mine operating face). This new technology provides fast acting dynamic voltage regulation (voltage support) while starting continuous borers and extensible conveyor belts. Additionally, if the mine suffers from a lower distribution voltage due to long cable lengths, this new technology will raise the overall voltage at the mining machine, which can increased mining machine production and lead to longer motor life. The technology is based on voltage source converters operating as static VAR compensators specially packaged for the harsh underground mine environment. While static VAR compensator technology has been successfully used in utility and large industrial applications for many years (including open pit mining and arc furnaces), it has not (until now) been applied in underground mining. The paper will present the problem of poor voltage regulation in underground mines on weak electrical utility networks. It will then discuss some of the alternatives that have been used to resolve this voltage problem. It will then introduce the new technology used to solve the problem and review the issues involved in using this technology in the harsh underground environment. Finally, the paper will present preliminary performance results from an actual installation in a large underground continuous mining operation in Canada.

May 1, 2003

By Dwayne D. Tannant

Digital photogrammetry allows rapid, remote measurement of millions of points, thus providing an unprecedented amount of spatial information. Research is being conducted to explore practical applications of digital photogrammetry for monitoring, surveying and mapping in surface mines. The performance, accuracy and operational ease of digital photogrammetry are discussed and practical aspects of conducting digital photogrammetry surveys are reviewed. Case histories from coal, diamond and limestone mines are presented.

May 1, 2006

By J. Mosher, G. Banini, J. Hollow, A. Villanueva

Prior to installation of High Pressure Grinding Rolls (HPGR) at PT Freeport Indonesia (PT-FI) a series of laboratory tests were carried out to determine the design parameters and also determine key performance indicators (KPIs) for the industrial unit. The design parameters derived from the lab test work were then scaled up to estimate the industrial capacity of the HPGRs to be installed. These parameters include specific power draw, specific throughput, and specific force, rolls speed, product size distribution and wear rate of the rolls. This paper compares the performance of the scale-up procedure against the installed industrial size HPGR. Overall, the specific throughput of the industrial size HPGR is higher by a minimum of 30% compared to the expected scale-up value. As a result of the high specific throughput, the specific power draw and grind sizes are below the scale-up expectations in the commercial application. The impact of these factors also contribute to a lower than expected wear rate on the industrial rolls. Installed rolls achieved a service life in excess of 18,500 hours relative to the target of 6,850 hours predicted from the laboratory testing.

Jan 1, 2012

By T. G. Joseph, M. Welz

ABSTRACT: Joseph (2002) introduced passive seismic monitoring to measure mining equipment performance. This paper evaluates the potential of passive seismic monitoring to correlate mining equipment operation with oil sands surface response, with a mining hauler as the seismic source. When applied to moving haulers, this action–reaction approach is complex. Vibrations from on-board equipment, such as pumps and tires, dirty the signal with noise. To facilitate any correlation, the signal must be cleaned up. Existing geophysical analytical techniques were manipulated to evaluate the noise problem and to filter sufficiently to permit an evaluation of whether a mining equipment action–ground response relationships in fact discernable.

Jan 1, 2011

By Jorge Amaya

A critical aspect of long-term open-pit mine planning consists in computing a production schedule based upon a block sequencing strategy. Such a schedule should specify when and if blocks should be extracted in such a way as to maximize NPV, while satisfying wall-slope and production capacity constraints. It is well known that this problem can be modeled with integer programming (IP). However, integer programming is not used in practice because the size of typical block models makes such problems intractable to standard IP solvers. In this article we describe a scalable IP-based methodology for solving very large (millions of blocks) instances of this problem. We show that embedding standard IP technologies in a local-search based algorithm we are able to obtain near-optimal solutions to large problems in reasonable time. This methodology has been tested in several mine wide block models.

Oct 1, 2009

By Jorge Amaya

A critical aspect of long-term open-pit mine planning consists in computing a production schedule based upon a block sequencing strategy. Such a schedule should specify when and if blocks should be extracted in such a way as to maximize NPV, while satisfying wall-slope and production capacity constraints. It is well known that this problem can be modeled with integer programming (IP). However, integer programming is not used in practice because the size of typical block models makes such problems intractable to standard IP solvers. In this article we describe a scalable IP-based methodology for solving very large (millions of blocks) instances of this problem. We show that embedding standard IP technologies in a local-search based algorithm we are able to obtain near-optimal solutions to large problems in reasonable time. This methodology has been tested in several mine wide block models.

Oct 1, 2009

By Chri Rule

"This paper tells the story of the rapid commercial application of stirred milling technology at Anglo American Platinum’s many Concentrators. The first stirred mill – a 10 000 litre IsaMillTM; the largest at the time, was commissioned in late 2003. The project development work was presented at SAG 2001. This operation was “proof of concept” and vindicated the decision to scale up the technology; allowing a rapid and extensive roll-out of mainstream regrind mills as well as several further flotation concentrate regrind mills, over the next six years.Currently 23 stirred mills are in operation with 64 MW of installed drive capacity – this paper describes the projects’ roll-out and the significant results achieved to date. Many operational problems have been solved along the way, some of these will be described. The introduction of the technology has seen a step change in metallurgical results and progressively decreasing operating costs."

Jan 1, 2012

TSUG Presentation Overview What/Who we are? Objectives & Mandate How to become a member (who qualifies)? Meeting Agenda?s & Frequency Q & A SMART is an association of mining companies that meet regularly to coordinate the technology development needed by the mining industry. Since 1995, the member companies and institutions have directed research and influenced the manufacturers and suppliers to improve surface mining technology and services. SMART actively supports learning seminars, collaborative research projects, and user groups. Members of SMART include some of the major surface mining companies in North America and Australia. These companies have recognized the value that collaboration can bring to the needs of individual organizations as well as the global mining industry.

May 1, 2008

By Rainer Süss

An investigation was carried out by Mintek to investigate the influence of a range of alloying additions (vanadium, cobalt, zirconium, antimony and germanium) on the formability and hardenability of alloys with gold content >90 wt%. This paper reports on the hardening mechanisms that can be utilised to increase the hardness of gold (>90 wt% Au) by conventional alloying, as well as the hardening effect obtained by alloying with specific elements. Preparation methods for the alloys are described, which include the steps of melting, annealing, quenching, cold working and age hardening. Focus is given specifically on alloys that were developed at Mintek with a gold content >90 wt%, which are not only harder, but exhibit good resistance to tarnishing and corrosion.

Oct 1, 2003

By Marcel M. Djivre

The paper will outline the destructive test methods and test procedures including the evaluation criteria currently used at the Materials Testing Laboratory (MTL), Sudbury, Ontario, Canada, a laboratory approved by the Ontario Minister of Labour for the purpose of testing or examining mine shaft ropes or other hoisting appliances. For the evaluation of the mechanical properties of rope samples used in "ultra-deep" single-lift shafts, additional discard criteria used in Ontario, Quebec and South Africa shall be presented. Most of the methods and test procedures currently used at MTL can also be found in the current CSA G4-00 Standard, Steel Wire Rope for General Purpose and for Mine Hoisting and Mine Haulage, published in November 2000. In this latest or sixth edition of CSA Standard G4-00, a new Clause 14 has been added outlining the requirements for in-service destructive testing of steel wire ropes for mine hoisting applications. The CSA G4-00 Standard is also intended for the manufacturing of new ropes, and includes requirements for raw materials and construction features for round strand and flattened strand rope, and locked coil rope in bright and galvanized finish. To-date the Ontario Mining Regulations require only that destructive test of new ropes be performed in accordance with CSA Standard G4-00, but does not require conformity to the Standard, and on the other hand the inservice wire ropes are required to be tested in accordance with CSA G4 and thus require conformity. The author recommends that the Ontario Mining Regulations (and regulations of other mining jurisdictions) be improved in order to ensure quality control in the manufacturing of wire ropes destined for mines in Ontario (and Canada). Also, the author recommends the revision of the CSA G4-00 Standard by the technical committee in order to address manufacturer?s concerns with respect to compliance, and harmonize the Standard with Internationally recognized Standards.

Apr 1, 2005