Search Documents

By D. Berkley

"Economic and environmental constraints drive more and more industrial organizations in using energy management as one of the means for addressing these issues. The recent increase in energy price could even make energy management a matter of “survival” in some cases.Experience shows that energy management is successful when the energy is managed like a resource, i.e. continuously, systematically, and in an organized manner, not like an expense, paying the bills once a month. This requires the development and implementation of an energy management program (EMP).This paper outlines some of the barriers, keys to success, components, and approaches to a successful energy management program, plant- or corporation-wide."

Jan 1, 2005

By D. T. Pritchard

"Introduction""No accounting system is very good, and all of them are infinitely variable*.”The purpose of this chapter is to discuss those facets of a typical accounting system which are most commonly encountered by operating managers in mineral processing plants. However, before concentrating in any detail on these it is important to understand the broad purposes and basic techniques of any accounting system in any major business.The three broad purposes of an Accounting System are:- Administering, controlling, and recording the flow of cash in and out of the business. Cash is, of course, converted into other assets (or stores of value) such as inventory, plant and equipment, etc. These assets also have to be administered, controlled and recorded.- Internal reporting to Management for information, for control, and for use in making business plans and decisions. - External reporting to stockholders, government, lenders and other outside parties.In this chapter we shall organize our discussion of accounting practice in mineral processing plants around these three purposes of accounting and focus in some detail on specific practices and techniques with which operating personnel will be routinely involved. This chapter is divided into the following: Accounting Basics; Administration, Control and Recording of Cash Flows; Internal Reporting; Planning and Budgeting; Cost Control; and External Reporting."

Jan 1, 1989

By A. A. Millar

THE output of coal from the Province of Alberta reached its peak; in the year 1928, when 7,334,179 tons were produced. Following this, a steady decline was recorded, and in 1930 a low mark of 4,564, 290 tons was made. Since that time, however, the tendency has been upward, and this year (1937) 5,551,682 tons were produced, compared with 5,696, 375 tons in 1936 and 5,462,973 tons in 1935. The value of the output in 1937 was $14,434,969, against $14, 720,004 in 1936. The coals of Alberta have been classed under three heads, viz., domestic, sub-bituminous, and bituminous The domestic (or lignite) and the sub-bituminous coals are used chiefly for domestic purposes, with the possible exception of the smaller sizes and the output of the two stripping pits at Stereo and Coal Valley The bituminous output is used mainly by the railways, for locomotive purposes, which, in 1937, accounted for 80.6 per? cenr of the total sales of bituminous coal. A fair proportion is sold for stationary engine and steam purposes and, in 1937, 25,000 tons were used in making briquettes at plants operated by the Canmore Coal Company, Limited, and Brazeau Collieries, Limited. The International Coal & Coke Company, Limited, used 99,500 tons in their plant at Coleman, for making coke. The bulk of the 66,000 tons of coke produced was sold for use at the smelter at Trail, B.C.

Jan 1, 1938

"Liberation is a key requirement for efficient separation in mineral processing. As a consequence of this an understanding of the inherent textural features of an ore is no longer possible since during the process of liberation, texture is destroyed. Knowledge of key textural features, such as mineral grain size and distribution, prior to breakage processes provides the opportunity to understand the textural drivers for ore hardness. Modern characterisation methods, including automated SEM-based techniques, provide the possibility of measuring mineral characteristics at a range of scales. This paper discusses how textural features of two different ore types in a porphyry copper deposit can be measured and interpreted at a number of scales. Standard breakage tests conducted on the ores indicate that one of the ores can be characterised as hard and the other as soft. The impact of mineral grain size and the presence and scale of vein type structures in the two ores have been used to determine the extent to which these features influence ore hardness.INTRODUCTIONIn order to effectively convert ore into metal, knowledge of both the processing stages and the characteristics of the ore are essential. Prior to the advent of technologies that enabled the fundamental understanding of the sub-process at each stage of processing and the measurement of appropriate ore properties the most effective way to understand how an ore would respond to a process was to put it through that process, for example the way to determine how an ore would break was to first break it. Existing comminution models seek to predict the size distribution of rock fragments as the result of applied energy based on knowledge of the rock strength. It is common for these models to consider the rock as homogeneous and despite providing important data for the design and optimisation of industrial comminution circuits these models are only applicable within a narrow range of operation. In order for reliable predictive models to be developed that account for the inherent ore characteristics, a step change is required in the type of measurements that are carried out to characterise an ore and the type of data that is extracted and used as model inputs."

Jan 1, 2016

By J. E. Amadi-Echendu, F. Stober, J. Ndlovu, L. R. Nelson

The Polokwane Smelter Complex (PSC) relies on a single 68MW high-intensity six-in-line furnace to smelt a planned 650 000 t/a dry concentrate to produce a platinum group metals (PGM)-bearing matte. As typical of a greenfields venture, considerable attention was paid to the project development and implementation stages of design, engineering, construction and commissioning. Somewhat unusual though, was the role of a dedicated multi-disciplinary "Operational Readiness" and support team, comprising the owners team and specialists from the furnace designer, HATCH, to effect a safe and rapid ramp-up to the design smelter capacity of 68MW. The challenges encountered in developing an effective partnership will be discussed. The modus operandi and roles of the "Operational Readiness" team during the design, procurement, construction and commissioning stages as well as that of the operational support team within the overall ramp-up objective will be presented. The "Operational Readiness" team was responsible for:

Jan 1, 2005

By A. C. Hawken, L. M. Strah

"The Report outlines the Conversion to Rubber Mill Liners and steel grinding balls from the old style Cobalt pocket liners and flint pebbles which had been used in 5'x22' Fraser-Chalmers tube mills for over fifty years. An outline of the past history and some of the plant modifications are mentioned as well.The details pertaining to considerations, modifications and repairs carried out on the mills are described. Factors influencing the rubber liner design are outlined along with the description of the rubber liner design.The performance and advantages to date are given and concludes with brief summary.HISTORYThe original amalgamation-cyanidation mill of Dome Mines Limited went into operation in 1912. Milling has been continuous since 1912, except for two periods; one of 17 months commencing in December 1917, and the other of about 12 months, when fire destroyed the plant in November 1929. Initially the capacity of the mill was 350 tons a day. In 1916 it was raised to 750 tons a day, following which there was a gradual expansion to 1,500 tons a day."

Jan 1, 1977

By A. McLean, M. Barati

In this paper, examples are presented of pyrometallurgical research and associated teaching activities during the past century within the Department of Metallurgical Engineering, now the Department of Materials Science and Engineering, at the University of Toronto. Throughout these years, pyrometallurgical research has been characterized by recognition of the importance of the interdependence of measurements and models as well as the development and application of sensors, for the generation, validation and practical implementation of new knowledge. The important role played in the delivery of lectures and participation in joint research by Adjunct Professors with strong backgrounds in the pyrometallurgical industry is described. Projects conducted in close collaboration with the industrial sector and opportunities for students to obtain practical experience working as teams on a "round-the clock" shift basis within an industrial pilot plant environment are outlined. These activities, together with the involvement of students in poster competitions and the presentation of papers at society conferences and technical meetings, are still vital elements in the development of pyrometallurgists equipped with the appropriate professional skills for subsequent employment within academia, government laboratories or the industrial sector.

Jan 1, 2015

By Roger V. Pierce

IN the last few years, much study has been devoted to increasing stoping efficiency. The reasons for this are shortage of manpower, shorter working hours, operating regulations, and shortages of essential materials. More efficiency in mining methods is needed to offset these adverse factors. In the past, attention has been centred upon haulage, hoisting equipment, mill flow-sheets, etc., but recently the spotlight has been focused on the cost of stoping and the cost of handling materials. Scrapers and scraper hoists have thus assumed greater importance. In order to make it possible for certain orebodies to be mined at a profit, it has been necessary to apply assembly-line practices to the streamlining of mining methods. All cycles of the mining operation must balance, and the sooner broken ore is removed from the working face, the sooner another round can be started. Since the introduction of scraper hoists in metal mines more than thirty years ago, much progress has been made in their design and application. Alert operators are now constantly watching for methods in which to apply scrapers. The saving of manpower in development work and the changing of mining methods that once employed manual handling of materials are increasing vital wartime tonnages. Essential ores from newly discovered orebodies are moving rapidly from stopes to reduction plants-because it is now possible to develop an orebody and place it in production with a minimum of manpower and development work. Today, speed is one of the prime essentials o mining. Everywhere, there is a concentrated effort to use experienced miners in breaking rock, in timbering, and in carrying out the various phases of mining that require many months of training. Much effort is being made to mechanize the working places because experienced men naturally prefer to work where the majority of materials are handled mechanically. In line with this policy, many new men are being taught the details of scraper work, because even green men can quickly become acquainted with scrapers and thereby release older heads to perform the more skilled phases of mining.

Jan 1, 1943

By G. W. MacLeod

The iron ore question in this country has been widely discussed for many years, but only recently has its real significance becoming generally understood. The exhaustion of the old Helen mine, in 1918, marked the last phase of hematite production in Ontario, and with the closing of the Magpie mine in 1921 , Canada ceased to be a producer of iron ore. For the past three years every ton of ore used in Canadian blast furnaces has been imported. In a recent issue of the Engineering and Mining Journal-Press, Arthur B. Pearsons, Assistant Editor, makes the following statement : Iron dominates the world. Some contend that coal is more vital. be-cause heat is needed to make iron and steel. But there are other sources of energy, more convenient and less costly and it is only a question of time when progress in hydro-electric development will have reached the point where coal will be but an incidental source of power and heat. Even more direct means than the generation of electricity by hydro-power eventu-ally will be developed by making available the latent energy of the sun. But iron; Science gives not the vaguest suggestion that anything will dis-place iron and steel as the most essential material tool of modem civiliza-tion. ? Hardness, tenacity, malleability-it possesses all these in unique de-gree. These are some of the qualities that make steel and iron indispensable in modern industry. The domestic consumption per inhabitant of the United States has climbed uniformly from 0.18 tons in 1900, to 0.36 tons in 1922. New kinds of machines and new types of structures are being devised every year; and steel or iron is the basis of most of them." It is unlikely that the Ontario Government were actuated by this motive when they appointed the Iron Ore Committee to investigate and report on the iron ore situation, nevertheless, these facts must have influenced them in some degree.

Jan 1, 1924

"The rocks of Notre Dame Bay form part of the Central Paleozoic Mobile Belt (Williams, 1964) of the Newfoundland Appalachians. The Central Paleozoic Mobile Belt of the northern part of the island consists predominantly of Lower and Middle Ordovician rocks overlain by Silurian elastic and volcanic sequences and underlain in the marginal zones of the belt by polydeformed metamorphic rocks of the Gander Lake Group (Kennedy and McGonigal, 1972) in the northeast and the Fleur de Lys Supergroup (Neale and Nash, 1963; Kennedy, Phillips and Neale, 1972) in the northwest. The Ordovician rocks of the Central Mobile Belt have been subdivided into a number of local groups in different parts of the region. The Lush's Bight Group was first defined by MacLean (1947) . Recently Marten (1971) has revised the definition of this group, as shown in Table 1 and his revised definition is accepted in the present paper. Plate tectonic models that have been proposed for the development of the Newfoundland Appalachian System have indicated that the mafic volcanic rocks of western Notre Dame Bay represent oceanic crust (Bird and Dewey, 1970; Dewey and Bird, 1971; Church and Stevens, 1970) which marks the remnants of the proto-Atlantic Ocean first proposed by Wilson (1966) . Such models infer that the mafic volcanic rocks constitute the upper part of an ophiolite sequence. Analyses of the lavas show that they are tholeiitic and support this conclusion (Papezik and Fleming, 1967; Smitheringale, 1972) . A complete ophiolite sequence, consisting of peridotites overlain by gabbros, overlain by a sheeted diabase dyke complex which passes upward into pillow lavas, occurs at the base of the Snooks Arm Group (Upadhyay et al., 1971 ) . Sheeted diabase dykes are known to underlie the lowest mafic pillow lavas of the Lush's Bight Group at several localities in Notre Dame Bay (Strong, 1972, and pers. comm.) . However, several conflicting points about the geology of this region suggest that although a typical oceanic crustal sequence of Lower Ordovician age is present, older rocks occur within the ophiolite terrane in several places (Williams, Kennedy and Neale, 1972) ."

Jan 1, 1972

By D. F. VanDine

The phases of a typical exploration program for sand and gravel resources include: (1) collection and assessment of existing information; (2) air photo interpretation and remote sensing; (3) ground investigation and mapping; (4) sampling and testing; and (5) data storage, retrieval, analysis and presentation. Depending on the purpose, time frame and funding available for the study, these phases, and the various techniques used within each phase, will vary. Once a sand and gravel deposit has been located, defined in size and quality, and found to be suitable for a given purpose, it can then be classified as a granular resource.

Jan 1, 1984

By J. P. Harrison, N. Bozorgzadeh, M. Dolowy-Busch

"It is common in rock engineering practice to characterize the triaxial strength of intact rock by using only data samples of small size. Practical guidelines such as ASTM support such sample sizes. In this paper, we investigate the reliability of the Hoek-Brown strength criterion estimated from such samples. For this purpose, we use an unusually large published set of triaxial strength data to randomly select a large number of data samples of small size to simulate the situation that frequently encounters in practice. The samples are generated with different arrangements with regards to the confining pressure. We fit the Hoek-Brown criterion to each of these samples, obtain estimates of strength parameters and compare them to those obtained from the complete data set. Our analysis suggests that estimates based on small samples are not reliable and can lead to both over- and under-estimation of strength.Additionally, we use these small samples to investigate the statistical methods for obtaining design values of strength as suggested by limit state design standards such as Eurocode 7. We show that, if used in conjunction with small samples, these methods do not guarantee a safe estimate of strength and in many cases lead to highly over-conservative estimates.We present a potential solution to this problem by augmenting the small data sets with Bayesian informative priors to give much more reliable estimates of strength. We conclude with suggestions for the development of informative prior distributions."

Jan 1, 2015

By D G. Boxall

As an alternative to heavy water cooling, reactors cooled by organic liquids are being actively developed in Canada under the sponsorship of Atomic Energy of Canada Limited. One of the areas in which development has been required is that of core materials. The factors affecting the selection of fuel canning and coolant tube materials are discussed. It is shown that S.A.P. is a potentially attractive material for these applications. The fabrication of fuel sheathing is discussed. Difficulties met due to large inclusions and blistering due to high hydrogen contents have been overcome by magnetic separation and vacuum sintering of the powders. High-quality tubes can now be produced by extrusion to finished size. A study has been made of the mechanical properties of fuel-sheathing tubes and bar stock. The stress rupture properties of the tubes subjected to uniaxial and biaxial stress have been determined. The biaxial stress tests were performed by internal pressurization. For times in excess of about 200 hours, the curve of stress against time to rupture is extremely flat. The secondary creep rates of

Jan 1, 1965

By I. M. Gordon

"INTRODUCTIONThe Hollinger tailing disposal plant is situated about 1 1/4 miles south of the mill. The area available for tailing covers 620 acres and is roughly 1 ¼ miles long by ¾ mile wide.Tailing was first deposited on the northeast section of the present site. This section, 1 mile long by ~ mile wide, sloped from northeast to southwest, the slope amounting to 106 feet between the northeast corner and the low land to the south west. The low land was wet and a considerable area was covered with muskeg up to 17 feet deep. It was drained by a creek running across the property in a southwesterly direction. Later, when more ground was needed, the low lying mining claims adjacent to the south and west boundaries were acquired to allow for expansion of the plant. This entailed some extra difficulties and expense that would not have been necessary had the whole of the present site been acquired with the original purchase.At the conclusion of milling, May 7, 1968, the site contains nearly 56 million tons of tailing. The top of the deposit is from 70 to 90 feet above the original low lying ground along the northwest, west and south boundaries."

Jan 1, 1969

By B. J. Keating

"AT PRESENT, it is not certain that any of the sulphide de in the Province of Nova Scotia attain the lower grade limit of 60 per cent sulphides over the minimum area of 1,000 square feet suggested as cut-off specifications for inclusion in this Symposium. However, several of them do include massive sections of substantial size and others represent concentrations of sulphide material that are well above average. It is felt, therefore, that a tentative classification of the deposits and presentation of their geological settings are justified and may help round out the genetic aspects of this study. Accordingly, data considered to be the most pertinent are assembled here in the event that some may fit into larger-scale patterns of mineralization that may take shape as a result of this investigation.The three principal massive sulphide deposits in Nova Scotia are the Stirling, the Smithfield, and the Walton. The locations of these are shown on the accompanying key-map (Figure 1).Three other deposits, the locations of which are also indicated on the map, are the Meat Cove, Rocky Brook, and Gays River de¬posits. Although these fall far short of the minimum dimensions and grade specifications referred to above they are singled out because they have received more than passing attention and are illustrative of the mineralization types to which they belong."

Jan 1, 1960

By C. Greimel

Modern roadheaders provide a safe and cost-effective, yet very flexible way of mechanical tunnel and roadway excavation. In the last years, SANDVIK Mining and Construction has developed a NEW ROADHEADER GENERATION, which incorporates new features, allowing significant improvements of underground excavation. Partial face cutting machines such as roadheaders excavate the desired profile by means of a cutter unit mounted on a swiveling boom. This flexible method for mechanical excavation makes the roadheader suitable for a large range of profile varieties and most rock characteristics. Over 1,250 roadheaders have been delivered since the 1960s from the Zeltweg plant of Sandvik Mining and Construction, with the current products ranging from the light-duty, 130kW MR220 machine, widely used in the tunneling and coal industry to the heaviest 300kW tunneling and hardrock mining roadheaders. Roadheaders are generally used in coal mine development, salt/potash mining as well as construction and hard rock mining. This paper describes the technology behind the succesful introduction of hard rock cutting with roadheaders, and aims to offer best practise operation experiences from various hard rock cutting sites.

Oct 1, 2010

By C. H. Bucknam

Net carbonate value (NCV) characterization methods for acid generation potential measurement originated from studies on the Carlin Trend during the 1990's and have been subsequently standardized through cooperation of the Acid Drainage Technology Initiative Metal Mining Sector and the American Society of Testing and Materials International. The paper describes the evolution and standardization of the NCV methods, the importance of mineralogy in interpreting the results and application of the methods to implementation of the Global Acid Rock Drainage (GARD) Guide.

Jan 1, 2011

By P. P. Rosario

A research project was conducted at the University of British Columbia (UBC) resulting in the development and evaluation of a novel comminution circuit incorporating autogenous grinding and parallel trains of cone crushers and high-pressure grinding rolls (HPGR). A primary driver for the circuit was to treat ore from deposits with clay and variable hardness. This paper summarizes the unique pilot-plant test program that was developed as a basis for experimental simulation and lists the main findings of the research, including the circuit?s potential operational cost savings compared to a conventional SAG circuit.

Jan 1, 2012

By Dart Wantland

"AbstractThe scope of geophysics in civil engineering and the nature of exploration geophysics are briefly discussed. Engineering problems amenable to geophysical attack are illustrated by specific examples. The various methods available, accuracy of results, and costs are treated. The possibilities of new uses of geophysical techniques are pointed out.IntroductionTHE SCOPE of geophysics in engineering is different than in oil or mining exploration. In civil engineering, geophysics solves specific problems; as for example, what is the depth to bed-rock along the axis of a proposed dam? The area to be surveyed is of limited extent, and the subsurface information .sought is relatively near the surface. The engineering geophysicist is not called upon to investigate geological basins or extensive mineralized areas or to probe for data to thousands of feet in depth. The geophysical tools employed in the three fields are, however, quite similar; the differences are mainly in the objectives.The Natural Geophysical ExplorationThe terms geophysics and geophysical exploration have been used heretofore and will .be employed in what follows. The question is, therefore, What is geophysical exploration?Geophysical exploration is a line of field work where measurements are made at the ground surface with special instruments to get geological subsurface information. Briefly stated, geophysics is a form of exploration that supplements geological work. It is a blend of physics and geology since physical measurements are made •at the surface of the ground that can be interpreted in terms of subsurface conditions."

Jan 1, 1953

The AG/SAG circuit discharge P80 is now increasingly referred to as the ?Transfer Size? or T80 for short. From the literature it is apparent that in circuit design some approaches to the sizing of AG/SAG mills as well as the ball mills that they feed use this parameter. This paper reviews whether the use of the T80 is appropriate in this context. In the course of the review examples of AG/SAG discharge size distributions measured from range of operating circuits are used to illustrate the arguments made.

Jan 1, 2012