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By J. Worden, D. Hughes, S. Smart, H. Zughbi

The enterprise wide optimization (EWO) of steelmaking and manufacturing is a multi-level, hierarchical problem which spans higher level corporate planning and scheduling through to the lower level operations of processes that produce and manufacture steel. External and internal system dynamics combined with process unit co-ordination create complex changing circumstances for the enterprise. This paper presents a scoping study as a prelude to enterprise wide considerations at an integrated steelworks to help inform the choice of appropriate model types and optimization techniques. The hierarchical, multi-level structure of the enterprise and the important spatial-temporal scales to consider are defined. Insights into the system were gained by analyzing a large set of dynamic operational data. Over two years of data were subject to both univariate and multivariate analysis with the intent of understanding the complex interrelations of energy flows on site, the inherent system dynamics of the energy network, system operational modes, aspects of planning and scheduling and the coordination between major processing units. This analysis was further used to evaluate the performance of the system in regards to energy utilization and understand the potential economic benefits derived from improved operational decisions.

Jan 1, 2015

By Noel W. Kirshenbaum

Difficulties and costs of transport markedly affect Canadian mineral producers because of distance from markets, weather conditions and rugged terrain. The chemical and physical nature of sulphide concentrates presents additional difficulties in handling and transport, resulting in higher costs which are ultimately borne by the mineowner. Troublesome properties include the thixo-tropic character of wet concentrates, freezing, susceptibility to autogenous heating, and fine particle size causing spillage and dusting losses. Canadian mineowners and shippers must contend with these problems and with stringent regulations governing the maritime shipping of concentrates. A "systems approach," in which complementary techniques in materials preparation, handling and transport are integrated, could reduce freight costs and losses for those selling concentrates, facilitate operations for those carrying and handling them and, in some cases, improve metallurgical processes in smelters receiving them.

Jan 1, 1969

By The Staff

Introduction In this paper it is proposed to discuss briefly some of the problems confronting the management of a gold mine in choosing a method of milling to recover the gold from various classes of ore. In order to simplify the discussion, the more common types of gold ores are classified from a metallurgical point of view as follows: Class 1?A: Free-milling ores which require only relatively coarse crushing. B: Free-milling ores which require finer grinding to release the gold. Class 2?A: Gold ores which contain the gold partly in the flee state and partly associated with a small amount of iron sulphide, and which do not require fine grinding. B: Gold ores similar to 2A, but which require fine grinding. Class 3?A: Gold ores containing copper in quantities insufficient to interfere to a serious extent with cyanidation. Gold ores containing copper in sufficient quantity to interfere with cyanidation but in which a large proportion of the gold is in the free state, the remainder being chiefly associated with the copper mineral, chalcopyrite. Gold ores containing copper and other sulphides, such as pyrite, etc., in which the gold is principally associated with these sulphides.

Jan 1, 1931

"In mills, metallurgical efficiency is important in every step of the operation through to the tails. Different problems which hinder metallurgical efficiency exist in different mills. One such problem occurred in the Bralorne mill at the tailings end of the circuit, where the washing efficiency of the filters was so low that serious losses in dissolved gold occurred.The new cyanide plant at Bralorne went on stream in August 1961. Test work done showed that: a flowsheet of grinding in water, jigging, thickening, agitating, followed by double filtration, gave satisfactory results and was more economical than a counter current plant. Two filters, 141 x 161, with approximately 700 square feet of filtering surface on each, were purchased and installed in series. Test work showed that this was ample filtering area for 500 tons per day.When the plant started up a density of 45% solids was maintained in the agitators, and a 20 ounce cotton dl1ck was used on the filters. Vacuum was between 23 - 25 inches. Under these conditions the filters would not work and only picked up a very slight skim of pulp. Various speeds were experimented with, 4 minutes per revolution being the most efficient. At this speed the thickness of the pulp on the filters increased to about 1/8”• It was therefore quite apparent that, under these conditions, the filters would not handle very much tonnage and the mill tonnage would have to be reduced drastically until the problem was solved."

Jan 1, 1967

By A. M. Nordale

Let us first trace a line, mentally, across Alaska and Yukon, starting at a point in the west slightly south of the delta of the Yukon river and from there continuing eastward, loosely following the 63rd parallel of latitude until we have passed beyond the eastern border of Yukon. We will make two pronounced digressions southward to include the greater parts of the Iditarod and Tanana River valleys. That visualized line roughly defines the southern boundary of permafrost. North of it lies a vast region, fully three-fourths of the area of the two territories, which includes Seward peninsula, the great Yukon River basin, and the tractless wastes of the Arctic. During some frigorific cycle in the distant geological past, the ground there was frozen to a depth of many hundreds of feet. How deep the frost actually penetrated is not known, but it has been found to exceed three hundred feet in many places. Nature afterwards provided a perfect insulating cover in the form of heavy moss and dense grass, which has protected the ground from the heat of the sun's rays during the intervening ages. This frozen condition has always been accepted as something indigenous to the North and little thought was given to -it until recently, when the United States Government and, I believe, the Canadian Government, began extensive studies of it, particularly in respect to its effect and bearing on the development of the great oilfields of the Arctic. Within this large region and but a short distance south of the Arctic circle are the three principal producing placer gold fields in the sub-arctic, whose hubs centre at Nome and Fairbanks in Alaska and at Dawson in Yukon Territory. The geological structure and history of the gold-bearing deposits of Dawson and Fairbanks are very similar and probably closely related. They are typical placer deposits produced by stream action during periods of erosion and inundation and subsequently covered with a thick layer of fine, powdery silt mixed with decayed vegetation which, locally, is termed 'muck'. The depth of muck varies from less than 10 to more than 250 feet, with the greater depth near the lateral edges of the valleys. The gravel underlying it is medium in size, well rounded, and composed mostly of quartz and schist. The proportion of sand or fines is approximately 40 per cent. No large boulders and little clay are found, for those districts, as well as that of Nome, have not been subjected to glaciation. The most common bed-rock found is either decomposed or hard schist, but infrequently it is slate, quartz, diorite, or a porphyry. The vertical concentration of the gold is invariably on bed-rock and in the lower few feet of gravel which overlie it. The horizontal concentration or paystreak is roughly parallel to the trend of the valley but does not ordinarily coincide with the course of the present stream. The width of the paystreak usually expands from a few feet at the head of a creek to several hundred feet near its mouth.

Jan 1, 1947

By F. J. A. van Ruitenbeek, M. Dalm

In the presented study test work was performed with near-infrared hyperspectral imagery (NIR-HI) on 36 ore samples from a South-American epithermal Au-Ag mine. The aim of the test work was to investigate if NIR-HI provides information about the alteration mineralogy of samples that can be used to predict their economic value. Mineral distribution maps were produced from the hyperspectral images by using correlation coefficients between the image pixels and a set of reference spectra. These maps showed that detection of mineralogy with NIR-HI can be used to distinguish; i) ore particles with low Au and Ag grades, ii) ore particles with high carbon contents, iii) ore particles with high sulphur contents.

Jan 1, 2015

By Minghui Li

China is the largest coal producer in the world. In 2012, the coal production in China is 3.65billion tonnes, accounting for approximately 49% of global coal production. The raw coal production in 2012 was 3.8% more than the year 2011. 56% of total raw coal has been washed. The increase in raw coal production also promotes technology to be developed and brings separation capacity become larger and larger in coal processing in China. At present, over 40 extra-large scale coal preparation plants (each plant has capacity of more than 10 Mtpa) are in operation in China, the largest one is 32.5 Mtpa. Heavy medium separation are widely used in new built coal preparation, the washing limit for thermal coal feed lower and lower, the equipment selection tends larger which brings the whole washing system simplified, the local equipment developed and manufactured are more and more used. By discussing designs of several typical thermal coal preparation plants and coking coal preparation plants in China, this thesis introduces the current design of China?s extra-large coal preparation plants, and sums up the prevailing design features and trends of extra-large coal preparation plants.

Aug 1, 2013

By William M. (Bill) Shaver

"The author will review the early history of shaft sinking as well as focus on the improvements made in shaft design and construction over the last fifty years (1970 to 2019) to predict how shaft sinking will change over the next fifty years and describe what the shaft sinking world might look like in 2070. INTRODUCTION It is a great honour to be one of your keynote speakers for the Fourth International Conference on Shaft Design and Construction being held in Toronto in November 2019. This is one of the opportunities we have to thank the Mining Companies of the world as well as the industries and companies we serve for their support of the mining contracting and shaft sinking business of Canada and the world at large. Many of these companies are represented here today. Without your support many of the innovations we will talk about today would not be possible. We would also like to thank all the companies that work with us in our business including all the contractors and suppliers who provide the various services we require. These include equipment manufacturers, engineering companies, project management companies and suppliers large and small who cater to our every need as quickly as possible. Without all these partners we would not be as good as we are. Many of these companies are our sponsors this week. Thank you from all of us! This is also an appropriate time to pause and think about those Shaft Sinkers we have lost and those who have been injured on our projects around the world. Please bow your head and remember the Shaft Sinkers you have worked with, who did not return home or those who returned home injured. Think about how we can continue the work of making shafts safer every day as we go forward with our projects so everyone goes home to their families safe and sound. Pause for a minute and thank you. The subject matter we have chosen to discuss today is “Shaft Sinking in the Next Five Decades”. How will the work be done, how fast will it be done, what will it cost, and why we think this may occur? It is appropriate to consider this over the next few days with this auspicious group we have assembled. Today, we will look back at all the advances that have been made over the last many years and look ahead to the future to attempt to predict what shaft sinking will look like in 2070. When I look around the room I recognize that many of us will not be around then so we need not worry about being wrong. Suffice it to say that the next 50 years will be very interesting and exciting for the shaft sinking business."

Jan 1, 2019

By Derek V. Ellis, Jack L. Littlepage

"Marine ecosystem effects ar1smg from the discharge of man-generated wastes to the sea can be schematized as: acute poisoning, chronic poisoning, enrichment, suffocation, temperature effects, salinity effects, toxin bio-concentration, changed production rates and changed species equilibria. A professionally designed site-specific monitoring program to check for such effects can not only safeguard the marine ecosystem from degradation, but it can also protect the industry involved from unanticipated remedial action after expensive construction has been undertaken. Monitoring programs should consist of three steps. Step 1 is an ecosystem survey which should be undertaken prior to final design of the discharge system and submission of applications for permission to discharge, because there can be considerable cost savings in obtaining information at an early stage in development. Step 2 involves location of the effluent field at the time of starting discharge, and analysing its dispersal behaviour. Step 3 consists of ecosystem monitoring with sampling stations and specific tests based on the accumulated prior information."

Jan 1, 1972

By W. A. Haley

This paper discusses how a large wheel loader should be equipped, with particular attention paid to tires and tread life, and describes the several steps that can be taken to provide favorable working conditions and reduce over-all costs. A comparison is then made of wheel loader production and costs vs those of power shovels, and the present and possible future applications of the wheel loader are outlined.

Jan 1, 1969

By Alan D. Brown

"Diesel-electric trucks are those that have some portion of the convention-al mechanical drive train replaced by electrical components. As larger and more powerful diesel engines appeared, the development of mechanical transmissions and related drive components failed to keep pace, and electrical generators and drive motors therefore came into use as an efficient means of transferring the mechanical energy of the engine to the driving wheels of the vehicle.The Berkeley Pit has been a major testing ground for the evolution of this type of truck. We now operate a haulage fleet consisting of conventional diesel trucks and two different types of diesel-electric trucks. There-fore, we have been able to obtain an interesting comparison of costs and performances between these three types of haulage units.In all phases of operation, the diesel-electric truck commands a favourable advantage over the conventional diesel truck, and represents a more efficient and less costly means of haulage. Nearly all manufacturers of heavy-duty trucks are now building, or have plans to build, such a truck."

Jan 1, 1966

By David Morley

This paper considers the ideal truck-excavator combination, defined as the combination resulting in the lowest direct unit cost, in consideration of multiple haul scenarios characterized by different haul distances, material and equipment availability. Through the application of Monte Carlo simulation, selected for its unique ability to handle the uncertainty of activity durations, the ?four to six passes? loading rule is shown to not correlate with the selection of the minimum cost fleet. Additionally, through the results of the simulation it is determined that the haul truck capacity has a greater effect on the overall efficiency of the system than does the excavator capacity. As a result, in order to arrive at efficient operations, the entire earthmoving system must be viewed as whole, namely, considering haulers together with excavators, as opposed to the popular method of first selecting a loading unit and then selecting a hauler obeying the ?four to six passes? loading rule. Furthermore, truck utilization and excavator utilization exhibit an inverse relationship and neither directly correlates with the overall efficiency of the earthmoving operation. The following conclusions are drawn: first, with limited financial resources, it is more valuable to increase hauling unit size before increasing loading unit size and second, predefined rules or generalizations, not based on evidence, potentially eliminate optimal truck excavator combinations from being considered.

Aug 1, 2013

By H. L. Cameron

General Statement In July, 1948, experimental aerial photography o shallow water zones on Northumberland strait was carried out by the Nova Scotia Research Foundation. This work was designed to test the feasibility of aerial photography for coastal surveys o various types, including seaweed and bottom detail surveys. In the course of the work at Lismore, undersea faulting was noted visually and was later clearly apparent in the photographs. In order to prove beyond doubt that the lineations photographed are actually faults, a ground check was made, and terrestrial stereoscopic photographs were obtained of these features where they intersect the shore line. There can be no doubt of their nature, and the type of faulting is probably thrusting due to compressive forces. This is indicated by the successive right- and left-hand displacements on intersecting faults. The age of the fracturing is post Lower-Pennsylvanian (Lismore) and is correlated with similar compression faulting in western Cape Breton. As far as can be ascertained, this is the first time that subsea faulting has been photographed, though it is quite possible that similar structures have been observed elsewhere. Location and Area Lismore is on Northumberland strait, approximately thirty-five miles east of Pictou (see index map, Figure 1). The area mapped from aerial photographs (Figure 2) is a strip approximately two miles long by a quarter of a mile wide. Figure 3 shows a stereo-pair of the aerial photographs used to construct this map. The terrestrial stereoscopic photographs (Figure 4) show one of the faults.

Jan 1, 1949

By Robert E. Loftus

"The author discusses the growth in the use of ocean-going bulk carriers for the transportation of mineral commodities, and predicts future trends. The various types of tonnage carriers are described, along with the special discharging gear used, the costs involved and the duties of some of the personnel.THE FIRST CONSIDERATION in planning the ocean transportation of minerals is the type of vessel to be utilized. The modern 'Bulk Carrier' bas proved to be the most successful vehicle for the purpose. I would there-fore like to describe this fleet in some detail and at-tempt to show the impact that the bulk carrier bas bad on the movement of bulk materials."

Jan 1, 1968

By Craig Haase

A. Introduction

Jan 1, 2003

By T. G. Joseph, E. Lampard

ABSTRACT: Surface mining operations must manage variability from within their operations as well as variability imposed upon them by external forces. A framework to manage both internal and external variability through the continuous review and adjustment of a mine plan during active mining lifetime operation is introduced, to minimize lost production and maintain operational safety. The observational approach of “observe, evaluate, interpret, predict, and adapt” is employed as the backbone of this approach. Although written with a surface mining operation in mind, the framework outlined in this paper would be equally applicable to any mining or processing operation.

Jan 1, 2011

By H. C. Boydell

Those connected with mining, prospecting, or mining geology in northern Ontario are familiar with the fact that it is a comparatively unusual thing to have assayed a sample for which the assay report shows no gold. Values of 20 cents to 80 cents per ton, or even higher, are extremely common. Whilst contamination by fluxes, faulty manipulation, or a desire, on the part of the assayer, to sugar-coat the pill for the client, may account for 20 to 40 cent values at times, it is un1ikely that they would a1ways do so. Exonerating the assayer from being necessarily at fault, what can be the cause of such a widespread distribution of gold (and silver) in minute quantities- of a dissemination .that, in the writer's experience, and so far as he is? aware, is not met with on a simi1ar scale in other parts of the world? Explanations that suggest themselves are, that the dissemination is due: 1. To a very widespread auriferous minera1ization, post-dating (epigenetic) the formation of the rocks in which it occurs. 2. To a general syngenetic distribution of gold in the volcanic rocks of Keewatin age that form so large a part of the sections of northern Ontario that have been prospected.

Jan 1, 1928

By Arthur Barnes, Mika Muinonen, M. J. Lavigne

"The carbothermic reduction of chromite ore to produce high carbon ferrochromium is among the most energy intensive metal extraction processes performed, due not only to the highly endothermic nature of the reduction reactions but also the very high operating temperatures required for the smelting operation to separate the chrome-containing alloy from the discard slag.KWG Resources and XPS have collaborated over the last 3 years in developing a patented (Winter) processing alternative to the traditional smelting operation in which all processing takes place in the solid state at temperatures many hundreds of degrees lower than those required for liquid processing. Amongst the attractions of the process are much lower capital costs, as well as reduced operating costs, particularly of energy.A techno-economic study on the new process identifies a reduction in overall energy consumption of 70% against conventional processing and approximately 40% lower than the current best practice. By utilising more natural gas than coal based energy sources, the KWG process is able to show an overall 50% reduction in greenhouse gas emissions compared with the most energy efficient current practice. The impact of the new process on future processing is therefore regarded as highly significant, with global energy reductions equivalent to the effect of completely eliminating energy demand from a country the size of Italy.The study concluded that the potential for this process to completely revolutionise the global ferrochrome industry should not be underestimated. Its impact reaches far beyond exploitation of a regional natural resource."

Jan 1, 2015

By Horace Freeman

Introduction This paper is an amplification of the paper presented by the writer at the last (1930) Annual Meeting of the Institute (1), and is somewhat in the nature of a progress report upon the introduction of pyrite into the field of Canadian consumption. The burner installed at the plant of the Canada Power & Paper Corporation, St. Maurice division, has been slightly changed in dimensions and has been put into continuous operation during the past year. As predicted, it has been possible to somewhat increase the steam consumption and at the same time decrease the amount of sulphur remaining in the calcine. The grade of the sulphur-dioxide gas produced has been maintained very steadily at 12 per cent, and sufficient experience has been obtained to determine the renewal cost of continuous operation. The object of this paper now is to encourage the development of pyrite, particularly by-product flotation pyrite, as it is shown that there is a very definite field in Canada for this material and that all the previous objections to the use of pyrite have been overcome, and that the use of the material in practice in paper mills has been developed to such a point that the operation of manufacturing the sulphite cooking-liquor is as simple as, or simpler than, the present style of operation with the use of sulphur.

Jan 1, 1931

By V. Chatain

The environmental assessment of historical mining sites contaminated with various inorganic species, as also the determination of remediation targets require a better knowledge of pollutant-bearing phases. The objective of this paper was to investigate the operational fractionation of arsenic (As) in an As contaminated (ca. 3 wt%) soil collected from a gold mining site in France, where mining activities and smelting processes of gold ores took place until 2004. Single and sequential chemical extraction procedures were performed to evaluate the potential mobility of As according to the fractions to which it was associated in the contaminated soil, and also the part of As sorbed onto soil particles. These procedures used provided information on the nature of As fixation processes in the mining soil studied. Results showed that As appeared mainly sorbed (ca. 72%) with iron on the soil particles, in particular amorphous iron oxyhydroxides. These results confirmed a potential risk of arsenic mobilization under acidic and/or reducing conditions, which frequently occur in mining environment. This research evidenced the importance of the knowledge of As-bearing phases to better predict the mobility of this pollutant and in turn improve the management of As contaminated sites.

Aug 1, 2013