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By A. Ismail

"The paper takes its material from three peat mining and power project feasibility studies sponsored by CANMET and conducted by Montreal Engineering Company Ltd. in the years 1976 to 1980. The role which peat may play in the Canadian energy prospectus is outlined, estimated and measured fuel peat resources are tabulated, and the economic and technical feasibility of mining peat for power generation is reviewed Recommendations are made for future work, and construction and disbursement schedules are developed for a combined peat mining and power generation project. The relationship between the mining of moss and fuel peat is discussed.IntroductionWhereas moss peat has long been produced in Canada, and exported for horticultural use , the underlying fuel peat has received little attention until fairly recently.In the seventies, however, the deepening oil crisis spurred Canadian interest in Irish, Finnish and Russian experiences in the utilization of fuel peat. Among others, Energy, Mines and Resources Canada had long been alive to the possibilities which indigenous peat offers, and in 1976 the Canada Centre for Mineral and Energy Technology (CANMET encouraged a proposal from Monenco to carry out a preliminary study and submit a report on the "" Assessment of Canadian Peat as an Alternative Fuel for Power Generation"". The report was submitted in April 1977. This was the first of a series of studies, and the authors of this paper were involved in its preparation.The escalating price of oil and the increasing problem of relying on its availability have combined to make alternative fuels more attractive. Peat, like other fuels previously uneconomic because oil was cheap, is now progressively gaining in viability. In addition to these factors, the utilization of peat has the following advantages: improvement in the country's balance of payments, by virtue of burning an indigenous fuel;creation of local employment for the mining of peat; improvement in land utilization;peat is a relatively clean-burning fuel, with low sulphur and ash contents."

Jan 1, 1980

By T. R. Eger

The Load-Haul-Dump (LHD) vehicle is a trackless, free-steered vehicle used in underground hardrock mining to move large quantities of ore/rock to haulage trucks, ore dump locations, or crushing stations. The purpose of this paper is to show, through case study examples, how principles of human factors can be applied to improve the overall design of the LHD vehicle to enhance line-of-sight (LOS), improve posture and decrease whole-body vibration exposure (WBV). Vehicle modifications (larger cab windows, lower engine profile, smaller buckets, angled radiator profile) can lead to improved line-of-sight. The use of secondary viewing devices, such as cameras, can also improve line-of-sight and allow the operator to adopt a more neutral sitting posture. Seating systems that are suited to the underground mining environment can result in vibration attenuation and less vibration transmitted to the LHD operator. The connection between vehicle design, line-of-sight and driving posture needs to be considered in order to continue to improve the design of the LHD and enable the operator to work in a neutral posture with minimal vibration exposure. Changes leading to improved line-of-sight, vibration reduction, and a neutral sitting posture will lead to fewer LOS related accidents and decreased risk factors for musculoskeletal injury.

Aug 1, 2013

By Erwin L. Zodrow

"For 25 chemical elements in electrostatically precipitated fly ash (Lingan coal-fired power station), concentration changes are studied as a function of increasing proportions of fines (ash particle diameter less than 45 micrometres). Elements that are involved when concentrations increase as the proportions of fines increase are likely to escape into the atmosphere. These are Th, U, As, S, P, Sb, Na, Ag, Zn, Pb, Ni, Ba, Sc, AI, Mo (and Bi, Ge, Ga, F and Li), i.e., more or less highly volatilized elements. Of the less volatilized metals such as Fe, Ca, Cu, Ti, K, Co, Mn (and lanthanides), certain portions presumably also escape as stack emissions. Diadochy and spinel formation in bottom slag is presented as an emission-reducing agent for certain metals.IntroductionThe Lingan coal-fired power generation plant, owned and operated by the Nova Scotia Power Corporation, produces annually about 140,000 metric tons of ash (the residual mineral content after burning coal). The tonnage is based on a 15 per cent average ash content of Cape Breton coal.For purposes of this report, samples of the hard, fused slag (bottom slag) that is accumulated at bottoms of boilers, and electrostatically precipitated fly ash (ep ash), were collected and investigated. Bottom slag is a minor component of the produced ashes.The ashes were surveyed and the presence of over 75 major, minor and trace elements is reported. From this survey, 25 elements were selected to establish elemental enrichment/depletion trends when the proportions of the less than 45 micrometre <45µm) fractions in ep ashes increase. The results are significant in that, taking the case of elemental enrichment, the elements involved are likely to escape into the atmosphere, i.e, highly volatilized elements. Depletion trends for elements are presumably associated with less volatilized elements during coal-firing. Quantification of the emission of atmospheric pollutants is not considered part of this work. ""Igneous"" minerals generated during coal combustion include spinels (found mainly in the bottom slag), quartz, glass and mullite."

Jan 1, 1982

By Masatsugu Morimitsu

This paper introduces new technology of oxygen evolution anodes which can be applied to produce copper, zinc, cobalt, and other metals by electrowinning. The anode consists of nano iridium oxide particles dispersed in amorphous tantalum oxide matrix as a catalytic layer formed on a titanium substrate. The anode can reduce oxygen evolution potential by 0.25 to 0.55 V compared to commercially available lead alloy anodes and can suppress unwanted side reactions such as manganese oxyhydroxide, lead oxide, cobalt oxyhydroxide which occur during oxygen evolution in the electrowinning solutions. This technology is effective for environmentally friendly electrowinning processes with low energy consumption and less anodic deposition.

Jan 1, 2011

By Edward Martinez

Laboratory studies had shown that the magnetite contained in serpentine asbestos ore was not uniformly distributed. Ore particles containing chrysotiye fiber responded to a magnetic f field; particles containing little or no chrysotile were essentially non-magnetic. Larger-scale tests, run with a magnetic pulley being fed various asbestos samples ranging in size from 1/4 inch to 5 inches, confirmed that magnetic separation could be used as a concentration step in an asbestos mill. Magnetic concentration was installed at the Black Lake and National mills of Lac d&apos;Amiante du Quebec and has allowed the extraction of lower-grade ore, increasing the life of the mines. In addition, preconcentration early in the flowsheet increased the value of the feed to the fiber recovery section. An increase in fiber production was achieved, as well as a decrease in maintenance costs due to removal of flow-grade tailings early in the flowsheet. Magnetic concentration of a coarse tailings from the mill resulted in recovery of additional fiber previously discarded to tailings.

Jan 1, 1979

By Fathi Habashi, Ahmet Deniz Bas

"The mechanism of leaching of semiconducting minerals such as PbS, ZnS, UO2, etc., has been the subject of intensive speculation by hydrometallurgy researchers in the early 1950s who assumed the formation of intermediate surface complexes that could be neither separated nor identified by physicochemical techniques. The electrochemical theory of leaching introduced in the late 1960s resolved this problem by comparing the leaching process to a corrosion phenomenon similar to the corrosion of metals. Few years later, experimental evidence showed that anodic and cathodic zones are formed on the dissolving mineral although no electric current is imposed on the mineral during dissolution. A discussion of these findings is outlined.INTRODUCTIONIn the early 1950s researchers realized that kinetic studies for leaching ores are as important as thermodynamic calculations. It was also during this period that the concept of species adsorption on mineral surfaces has dominated the interpretation of the mechanisms of most reactions. This may have been due to the fact that many researchers of this period came from the mineral dressing sector and were influenced by flotation theories. However, when the knowledge of lattice defects and the semiconductivity of minerals became known and their importance in extractive metallurgy was realized, there was a need to explain the leaching reactions in light of these modern theories (Habashi, 1969, 1970). Semiconducting minerals of importance in metallurgy are two categories: the sulfides such as those of copper, lead, zinc, and the oxides such as those of uranium."

Jan 1, 2016

By Y. Long

The deep-hole surface blasting technique is a prime method of iron ore mining. Blasting fragmentation is one of the important economic indicators that measures the blast method to obtain the iron ore. To improve the efficiency of the blasting method and further reduce the cost of the subsequent processing of iron ore, this paper summarizes measured data gained from a certain amount of blasting test conducted in an iron ore mine in Guangdong province, China. According to the data analysis, there are differences on iron ore blasting fragmentation by different indicators of deep-hole blasting, such as decoupling coefficient of charge, contact state between charge and borehole wall, and change of detonation position in charge. These factors were compared in terms of relevance and impact. Research shows: under certain rock conditions, the decoupling coefficient of the charge has a best range related to blasting fragmentation. Since the detonation position in charge determines the direction of propagation of the explosion stress wave through ore and rock, bottom initiation and mid initiation will help to improve the iron ore blasting fragmentation in joints fractured rock and ore. The research conclusions have important application value for program design of iron ore surface blasting and to guide other types of rock surface blasting.

Aug 1, 2013

By Errol Ladner

The application of large-diameter bore holes in underground operations at Heath Steele was first tried in February, 1975. Since that time, 90,000 feet of 6-l/2-inch holes have been drilled, primarily in open blasthole stoping, for a total of 1.4 million tons, 37% of underground production. This paper deals with a review of drilling with conventional percussion longhole drills, a practice which is still utilized at Heath Steele, and the changeover to accommodate the use of larger blastholes in underground operations. The discussion will include layouts for 2-inch-diameter blasthole stope blocks, 6-inch-diameter stope blocks, trials for I. T.H. (in-the-hole) stope rooms, and drill pat/ems, drilling and performance. The complexity involved in the development, drilling and blasting of 2-inch blastholes is overcome by the over-all simplicity of drilling and blasting in I. T.H. stopes. This has made the practice of open blasthole stoping more economical and efficient. The future indicates an increase in the company&apos;s I. T.H. program. Investigations are being undertaken regarding longer holes to decrease development costs. A VCR stope is also being developed for trial.

Jan 1, 1979

By E. Ghali, B. Arsenault

Aluminum alloys play an important role in the manufacturing of air and ground vehicles. However, with such alloys, corrosion damage is often found on structural components subjected to fatigue loading. The alloying provides large benefit in terms of the high specific tensile strength (ultimate strength/density ratio) to the aluminum alloy but causes the aluminum alloy to be more sensitive to localized corrosion due to complex microscopic heterogeneities such as secondary phases. This paper investigates thermal spray coating namely arc spraying to evaluate the protection against environmentally assisted cracking (EAC) and localized corrosion on Aircraft structural 7075 T651 aluminum alloys. In particular, EAC and pitting corrosion at the interface coating-substrate are a challenge for thermal spray protective coatings on aluminum alloys under cyclic load and immersion. To address these issues, different surface preparation techniques prior to arc spraying were considered such as chemical de-oxidation, laser ablation, shot peening and grit blasting. Results indicate that surface preparation and improved coating process parameters play an important role to provide a coating conferring a protection against both localized corrosion and EAC.

Jan 1, 2006

By G. R. Heffernan

"In the early 1970ssteelmakers worldwide were looking forward to many years of expansion and profitability. Huge government investments in Europe, the United Kingdom, Japan, Brazil, and Venezuela were committed in anticipation of growing market s based on long-term OECD forecasts. In 1973 the first OPEC oil shock occurred. Steel demand shrank. Restructuring became the buzz word of the day as billions of dollars in taxpayers&apos; money was poured into eliminating excess capacity and labour. In the United States, where government help was not available, inefficient companies went bankrupt; capacity was cut to 100 million tons from 155 million tons. The industry throughout the industrialized world shrank. By 1979the world economy seemed back on track and a modest degree of optimism could be detected in the international steel fraternity. Then came the second oil shock. By 1982 the industry was in the midst of another shakeout. More bankruptcies, more rationalization, and fewer jobs resulted. In Canada some well-known companies came close to the brink as low prices and high interest rates took their toll. In the light of the turmoil in the steel market over the past 20 years an attempt to forecast the trends through to 2001 is intimidating.However, there are good reasons to be optimistic today about both markets and technology.An economic super power is emerging in western Europe as 1992 draws near. The creation of a single market of 320 million well educated and economically ambitious people has major positive implications for steel demand. The mega projects of the channel tunnel, a European network of high speed railways, and the London docklands are the forerunners of greater things. Still to come is another $200 to $300 billion by the year 2001 in identifiable major projects for highways, railways, airports, water and sewage systems. Add to that the demands of an increasingly affluent population for automobiles, appliances and housing. On top of all that place large increasing demands for electric power and you have a potential beyond anything seen during the 1970s and 1980s. In 1988 the EEC steel industry operated at 90% and in 1989 at 92% of effective capacity. A surge in spot prices indicated that 92% was close to the ceiling. This pace moderated in early 1990 but any slack will probably be taken up rather quickly."

Jan 1, 1990

By R. R. Stone

"This paper will examine the role of debt and equity in project financing and will illustrate the impact on the return to the project sponsor of each type. Conventional debt sources will be examined, as will product purchaser advances, foreign export-import bank loans and lease financing. The paper will review guarantees, charges against the project, dividend restrictions and other commitments. It will also discuss various features of sales contracts and the degree to which they can assist in securing financing. IntroductionThe cost of bringing new mining projects on stream is escalating significantly more rapidly than general rates of inflation. Reasons for this include the higher costs of safeguarding the environment and ensuring the health and safety of workers. The need to develop properties in more remote areas is also a significant factor. These higher costs have not been matched by increases in metal prices, making the task of financing these projects ever more difficult. At the same time, the imagination of borrowers and lenders seems boundless, and innovative schemes for financing projects are constantly being unveiled.It is probably safe to say that no two projects have ever been financed in precisely the same way and the number of financing options for any project is limited only by the imagination of the sponsors themselves. The objectives of the project sponsor represent the most important factor in determining the scope of possible financial arrangements. For example, the sponsor may wish to maximize over-all company leverage by isolating each of its projects in separate companies. In so doing, it hopes to facilitate more ventures than would otherwise be the case. These objectives point toward true project financing. Additional objectives may be to develop a number of its properties by joint venture and to reduce the amount of debt on the sponsor&apos;s balance sheet. Those sponsors whose objectives include minimizing over-all financing costs will wish to increase the number of financial options and, as a result, will not be so concerned with effecting true project financing. This approach may also provide ""greater certainty that tax benefits are utilized quickly."

Jan 1, 1980

By R. C. Lo, M. D. Scott

"This paper reviews tailings management at Highland Valley Copper, and outlines main features of its tailings storage facility enclosed between the H-H and L-L dams. Key management focusses are: energy efficiency, cost effectiveness, safety and integrity of the tailings impoundment, environmental protection, and reclamation after decommissioning. Main features of the tailings facility include: high international standards for seismic and flood design criteria, water management and water quality monitoring, operations and construction optimization, reclamation and decommissioning plan, and geotechnical challenges associated with the complex geology of the L-L tailings dam foundation.IntroductionHighland Valley Copper stores its tailings mainly in the Highland Valley tailings facility (ultimate capacity: 1.8 billion tonnes). Smaller tailings storage facilities were operated by predecessor companies: the Number One Pond, the Trojan Pond at Bethlehem and the Highmont Pond at the Highmont operation as well as backfilling the Heustis and Jersey lona Pits at Bethlehem. These areas are currently not in use, and are in the reclamation phase prior to decommissioning. This paper focusses on tailings management in the main facility. As indicated in Figure I, the facility includes three tailings dams: these are, going from east to west, the H-H, J-J and L-L Dam, named after the alignment alternatives in the initial feasibility studies. From 1970 to 1977 Canadian Bechtel Ltd. advised Highland Valley Copper&apos;s predecessor company Lornex, on tailings storage at the H-H and J-J Dams and on the L-L Dam. Since the completion of the L-L Starter Dam in 1977, Klohn Leonoff Ltd. has provided ongoing consultation and construction monitoring of the raising of the L-L and the H-H Dams. The J-J Dams is currently buried by deposited tailings. This paper reviews key tailings management focusses and main features of the tailings facility."

Jan 1, 1992

"The gravimetric dust sampler is one of the tools now available to the industrial hygienists for determining the worker &apos;s exposure to the numerous types of particulate matter that may be present in the workplace. The paper &apos; reviews the different sampling trains that can be used for the two major criteria for respirable dust and some of the sources of error in this dust assessment technique.IntroductionIt may be stated simply that the measurement of airborne dust in the working environment is done for one or two reasons: namely, for engineering control purposes and! or to evaluate the potential for toxicological insult arising from the inhalation of dust particles.This paper reviews the progress made in the development of dust-assessing instruments, particularly the gravimetric types designed to meet British and U.S. dust criteria , and discusses the limitations in their use for this purpose."

Jan 1, 1981

By O. E. Humeniuk, A. I. A. Salama, M. W. Mikhail

"Performance testing of prepartion plants is referred to as plant audit. It evaluates plant performance under normal operating conditions and is aimed at improving yield through knowledge of actual process performance and interactions between different processes in a plant.This paper describes the program to evaluate the performance of several Canadian preparation plants. The performance test requires the planning of a sampling campaign that would include all circuits in the plant. Samples are analyzed to determine washing characteristics (screen and float-sink), ash and per cent solids of feed and products of separation units in the plant. Performance characteristics are established based on analysis and material balance. Specific recommendations can then be made to improve recovery, and identify and explain potential causes of apparent deficiencies.The objectives of the program are to reduce the cost of production by improving recovery of clean coal and, in tum, to reduce disposed tailings, establish baseline information on coal preparation plants performance in Canada, and define R&D work needed to optimize plant operation."

Jan 1, 1993

By D. A. Stokes

"In October of 1980, Fording&apos;s 15 000-ton capacity clean coal silo was put into operation. The silo was unique in that it was designed to allow the mass flow of material, coupled with a sophisticated computer-controlled dynamic loadout/weighing system.On May 1, 1982, an explosion, attributed to a methane buildup, devastated the top of the silo. .As a contingent plan to minimize the effect of the production loss the conveyance to the silo top was reconstructed and the silo&apos; was back in operation by mid-June 1982, although the silo top was left open to prevent further methane buildup. As dust emissions occurred during loading ofthe silo, an extensive study was undertaken to establish dust control for the silo, while at the same time providing methane detection and control.The study, conducted for Fording by the Cambrian Engineering Group of Calgary, involved an extensive search and investigation of existing coal silos. The study concluded that there IS no universally accepted method of controlling methane emissions in coal silos.The study also produced a unique conceptual design for handling methane, while at the same time, protecting the environment . Fording&apos;s Clean Coal SiloThe silo, located at Fording Coal&apos;s Fording River metallurgical coal operation, is utilized for the storage and load out of cleaned thermally-dried metallurgical coal.The silo was constructed in 1979 and 1980 to reduce unit train loadout times and to facilitate the handling of “special shipments"" of coal. The silo went into operation in October 1980, under manual control and utilized computerized, automated loading by February 198I.The silo is 21 m in diameter and 76 m high, with a nominal capacity of IS 000 live tonnes. The coal storage portion of the silo is 21 m in diameter and 48 m high, utilizing 2 steep-angled hopper outlets allowing mass flow of the stored coal during train loading. Each hopper has a control gate and a discharge chute, one chute for bulk loading, the other for trim loading of coal into the rail cars."

Jan 1, 1986

Gold recovery from refractory ores can be very difficult and complicated depending on the causes of the refractoriness. Typically, a fine wind and/or the oxidation of the gold-bearing sulfide minerals are required to liberate gold from the host rock matrix. Mineral separation techniques, particularly surface¬wettability based separation (i.e., flotation) and magnetic separation, can be used to pre-concentrate the gold and sulfide minerals, or to remove mineral species that are harmful either to the oxidation of the gold-bearing sulfides or to the cyanidation following the oxidation. In this paper, several processes are described, including oil-agglomeration flotation recovery of fine-grained gold and sulfide, reverse flotation of carbonate minerals prior to pressure or bio oxidation, reverse flotation of elemental sulfur after pressure or bio oxidation but prior to cyanide leaching, and magnetic concentration of gold-bearing iron oxides. The integration of these techniques with gold hydrometallurgical processes may make the economic recovery of gold from an otherwise uneconomic refractory ore possible.

Jan 1, 2011

By Suping Yao, Chuanyu Jiang

In the last decade, the copper industry in China has witnessed a significant change. The capacity and production of refined copper has grown remarkably from 1.5 million tons in 2002 up to 5.88 million tons in 2012. And now, China has become the biggest copper producer in the world, counting about 30% of the global refined copper production. This paper summarized modern copper smelting and converting technologies employed in China copper industry, such as OT flash technology, TSL (ISA/Ausmelt), SKS bottom blowing, Jinfeng side blowing, etc…This paper also presents some key development and improvement of these technologies up to date from their practical application in China, what will contribute as great value to any new / or renovation copper smelting projects down the road. As an engineering company in China, NERIN has been involved in many of these projects in the past decade, played an important role in the engineering works and accumulated intensive experiences. NERIN is one of the best choices for the world clients in the copper industry, providing quick engineering service, delivering cost effective projects.

Jan 1, 2014

By C. R. Kerr

"This paper describes the revisions to the heating and ventilating system at the Frood-Stobie mill, which resulted in substantial savings in energy costs.IntroductionInco Metals Company, a unit of Inco Limited, is involved in the mining and processing of nickel-copper ores. The Ontario Division of Inco Metals consists of 10 operating mines, with 5 mines and open pits on a standby basis, and 10 pro- cessing facilities, located in Sudbury, Port Colborne and Shebandowan. In 1980, the Ontario Division&apos;s energy expenditures amounted to $87,000,000.Due to the accelerating cost of energy, the Division established an Energy Management Program in 1975 to define, evaluate and implement measures to reduce energy cost and consumption per unit of output by 10% by 1980. This falls in line with the goals set by the mining and metallurgical task force on voluntary energy conservation.To effectively implement the program, Plant Committees were established at each plant and mine area, with an energy management coordinator appointed to coordinate the activities. The Plant Committee&apos;s responsibilities include identifying the major areas of energy consumption, isolating areas with large potential losses and determining what action should be taken to improve energy efficiency.Within a five-year period from 1975 to 1980, the Ontario Division has been able to cut its energy consumption by 8.9 trillion BTUs, the equivalent of 1.5 million barrels of oil."

Jan 1, 1981

By Robert B. Parsons

"This month, Tax Notes focuses on two features which can potentially ""dress up"" a new issue of common shares to make the shares more attractive to investors. Attaching warrants to a share issue is a relatively common practice, and recent years have seen an imaginative variety of different kinds of warrants, some of which can be subject to somewhat different tax treatment . A less common financing strategy which certainly deserves some consideration involves the possibility of utilizing ""Share Purchase Tax Credits "" in conjunction with a new share issue.IntroductionPrevious subjects covered in Tax Notes have dealt with flow-through shares and other tax angles which can make equity issues more appealing to potential investor s. Two other techniques which can add zest to a new stock issue involve the utilization of warrants and ""share purchase tax credits"" (or SPTCs). This article takes a brief look at the better known subject of warrants and the lesser known matter of SPTCs.Of course, this paper presents only a relatively general summary of the income tax implications of warrants and SPTCs, and is not intended to be a definitive commentary on all of the detailed and complex tax issues that might be relevant in the circumstances."

Jan 1, 1985

An optimized long-term mine planning determines the best order of material extraction, so that the Net Present Value (NPV) becomes maximum. In the case of oil sands surface mining, one of the key constraints in NPV maximization is the volume of tailings slurry that will be generated downstream. Specifications of tailings slurry are also important from environmental perspective. Moreover, most of the material that will be used for the reclamation of tailings ponds in later periods is generated in extraction and processing of oil sands. In this paper, an integrated optimization framework is proposed to maximize the NPV of the produced oil sands, with respect to tailings capacity constraints and reclamation material requirements. A mixed integer linear programming (MILP) model is developed to find the optimal solution for long-term mine planning problem. The proposed model is coded in Matlab and has been run using CPLEX for verification. The results for real-case oil sands dataset show that the optimal production schedule meets material requirements for reclamation, tailings volume is within tailings capacity range in all periods and the production schedule follows the predetermined horizontal direction.

Aug 1, 2013