Search Documents

By Alan E. Gallie

FOR many years the Witwatersrand has been the leading gold mining r camp in the world and, to a Canadian mining student, could not fail to be of overwhelming interest. The vast scale upon which the operations are conducted, the enormous production accomplished, and the perfection of the operative technique, have all so forcibly impressed themselves on his memory that it is difficult to select any one feature as more outstanding than another. For the purposes of this paper, however, the author has selected the very first feature of mine operation with which he came in contact, namely, shaft sinking, as it reflects, quite as well as any other, the spirit of mining in South Africa. Early mining in Johannesburg was by open cuts or trenches, dug along the outcrops of the reefs. The ore was thrown from bench to bench to the surface. As the depth increased, rock was hoisted by bullocks. In 1887, the first shafts were sunk and true underground work began. At the same time, boreholes were put down to test the continuity of the reefs at depth. The first was at the Village Main reef. It cut the South reef at 517 feet and the Main reef leader at 581 feet. The Main reef leader assayed eleven penny-weights. Subsequent boreholes proved the reefs down to thousands of feet. Many companies secured deep-level claims as a direct result of the information obtained from the early holes. These companies then held land on which there was no readily available ore. In order to get to their pay rock, vertical shafts through the upper strata were necessary. Shareholders were impatient, and shafts had to be sunk as speedily as possible. The old methods of shaft sinking were investigated, new methods developed, and soon all records were being broken. In the last thirty-five years, the record has been slowly advanced, and last summer it was again broken to stand at 430 feet in a 31-day month. During the period from 1915 to 1935 inclusive, in the Witwatersrand district, 96 miles of shafts were sunk. Today, with the advance in the price of gold and the increase in the mining area, there are over twenty-five major shaft-sinking operations being carried on.

Jan 1, 1937

By A. J. Paul Laprairie

"ADVANCE planning of mining methods, from the first development openings to stope layout and pillar recovery, has long been accepted as a normal method of operating a mine. Recently, mine managers have become increasingly aware that advance planning of cost and accounting controls can also be considered a normal method of operation. The use of such controls is wide-spread in manufacturing industries. In mining, the gold mines of South Africa have pioneered, with marked success, in this field and have been closely associated with most of the research and field work in accounting control. Canadian mine managers are also beginning to realize the advantages of using planned costs. The control procedures which subsequently have been introduced at various mines have come to be known by such names as ""Responsibility Costing"" or Budgetary Control"".Budgetary control, the term used in this paper, is based on the concept of decentralized authority with centralized control. ;The control is achieved by measuring results against yardsticks which are in the form of budgets or standards. Bud-gets are made for the future activities of each possible operation as planned by the department head, and attention is directed to variations from this plan. Furthermore, the control process charges to each operation only those costs which are incurred directly for that operation, and which can be controlled by the person in charge. Thus, budgetary control relates results to the officials responsible for those results. Expenditures are analyzed according to the organizational structure of the mine and the people who run it, and not according to production processes."

Jan 1, 1960

By D. François-Bongareon

"In previous publications by the author, significant advances and generalizations of the theory of sampling of broken ores, prompted and confirmed by experimental results, have been presented. This paper shows how to implement these theoretical results in practice. The models to be used are reviewed, with a description of the various sampling parameters involved. Then the methodology for the experimental assessment of those parameters, including segregation factors, is described in simple and practical terms, along with the use of handy sampling protocol charts. Finally, the particularly important case of processing data from a sample-tree experiment is detailed, and examples of applications covering all situations and types of experiments are provided.IntroductionThe reliability of a sample of crushed material , i.e. the expected (average) deviation between its true grade and the true grade of the lot it comes from, mostly depends upon six factors:• the size (mass) of the sample (and to a minor extent, for small lots, the size of the lot);• the size of the rock particles (degree of comminution)• the nature of the mineralization at microscopic scale (i.e., within even the smallest particles);• the geological nature of the mineralization and mineral of interest;• the grade of the lot in the mineral of interest; and• in some cases, the state of segregation of the lot.In practice, one should first disregard segregation problems, and assess sample variability in the segregation-free case. Once the numerical parameters governing this variability have been assessed, then segregation factors can be assessed in turn. In the case of laboratory standard sample preparation procedures, segregation can usually be disregarded altogether."

Jan 1, 1993

By Z. Wu, L. N. Y. Wong

The present study develops the numerical manifold method (NMM) as a tool to investigate the progressive failure in rock slopes. The entire processes of the progressive slide surface development related to crack initiation, propagation, coalescence and degradation to eventual catastrophic failure are successfully captured. To overcome the limitation of the original NMM associated with an improper removal of the interface cohesion of the discontinuities, the displacement-dependent cohesion removal method is adopted. Simple examples of failure of rock slopes containing different arrangements of discontinuities are modeled and their results are compared with those based on the popular limit equilibrium method proposed by famous pioneers Jennings and Jaeger. In cases of coplanar non-persistent discontinuities, close results are obtained despite the differences in the consideration of the stress concentrations at the crack/discontinuity tips. In cases of non-coplanar discontinuities, since the influence of the tensile strength is considered by both the Jaegers model and the NMM, the Factor of Safety (SF) values are similar despite the difference in the failure path trajectories predicted by these two models. The results also reveal that the original NMM without the displacement-dependent cohesion removal method is always more conservative due to the improper removal of the interface cohesion. The displacementdependent cohesion method can to some extent alleviate such a limitation.

Jan 1, 2015

By C. J. Kerr

"A recent information sheet from the Mining Health and Safety Branch of the Ontario Ministry of Labour was sent to all Ministry inspectors and engineers. The subject title was' 'Two Brakes on a Hoist Carrying Persons"" and it quotes mining regulation 699, sub-section 206(i):No hoist shall be used for the transporting of persons unless it has a braking system consisting of at least two sets of mechanical brakes to stop and hold the drum for the shaft conveyance transporting the persons.The intent of the regulation is that each of these brakes is to be set so that, individually, they can safely stop the drum carrying persons and also hold the drum without movement with the maximum manload.This can be achieved in the following ways: Single Drum Hoist-one brake on each side of the drum, one brake on the drum, one brake on the pinion shaft, where disc brakes are used two separate disc brake assemblies on the disc. Double Drum Hoist, brakes on companion drum can serve as backup brake only pinion brake with one drum unclutched.Friction Hoist, one brake on each side of drum As new hoists can be manufactured easily with a two-brake system, attention will be focused on retrofitting pinion brakes to older hoists.A brake mounted on a pinion shaft is designed purely as an emergency brake in the event of main brake failure , controls malfunction, and power loss."

Jan 1, 1989

By M. Lytle

"The Corbin area of southeastern British Columbia has been a coal mining area since 1908. Byron Creek Collieries Ltd. Has operated its Coal Mountain Mine in this area from 1974 until the present. In February 1981, this company was purchased by Esso Resources Canada Ltd.Coal Mountain is structurally complex and standard computer algorithms are not applicable to model the overturned synclinal structures and faulted bedding surfaces. This paper discusses two approaches used by Esso Resources staff to model the geology of Coal Mountain.The first approach projects digitized cross-section data along trend to develop a large data base which correctly approximates the shape of the structure. The spatial orientation of the structure is corrected by merging the generated data set with drill-hole data. The second approach uses digitized cross-section and bench-plan geology to generate a block model of the coal reserve.HistoryThe Coal Mountain Mine, also known as the Corbin Mine of Byron Creek Collieries Ltd. is located 24 kilometres south of Highway 3 in southeastern B.C.In 1905, two American businessmen recognized the coal potential of the area during a horseback tour. The two businessmen, D.C. Corbin and E.J. Roberts, formed the Corbin Coal and Coke Co. to mine and market coal from their newly acquired 6075 hectares of coal licenses. By 1908, the town of Corbin was under construction, a 22.4-km rail spur was constructed from the mine to the main CPR line and the first underground mine began to produce coal. An open-pit operation was also developed at the 1828-metre elevation using a steam shovel loading into rail cars. The company operated continuously until 1935, when a lengthy strike forced suspension of operations.In 1943, the Consolidated Mining and Smelting Company Ltd. (now known as Cominco Ltd.) operated two surface mines to produce coal for its smelters at Kimberley and Trail, B.C. This operation ceased in 1948."

Jan 1, 1982

By G. E. Parsons

"The Bidgood is a small gold mine about 5 miles east of the main Kirkland Lake camp. Since the beginning of production in 1934, gold having a value of $5,000,000 has been produced from the property. Practically all of this production has come from seven veins in a diorite stock that intrudes the Timiskaming sediments and lavas of the area. The veins consist of quartz, pyrite, and molybdenite with minor amounts of chalcopyrite, calcite, and tellurides, and occupy northeast striking and northwest dipping thrust fault fractures. They have no apparent direct structural association with the faults of the main Kirkland Lake camp or the Larder Lake 'break' to the south; however, the veins closely resemble the former in their mineralogical composition and in their close association with syenite intrusives.ROCK TYPES AND THEIR STRUCTURAL CHARACTERISTICSThe dominant and, from an economic standpoint, most important rocks in the ore area consist of two separate families of Algoman intrusivesa diorite and a later syenite group."

Jan 1, 1954

By Gerhard W. Heinrich, Gerald V. Schroeder, Daniel A. Murphy, Daniel F. Suarez, Jamie B. Beauchamp

"Washwater 'Finger' sprays were installed and tested in the copper/nickel separation circuit at Strathcona Mill to improve flotation capacities and related metallurgical performances. The new spray design features submerged sideways introduction of wash water into the flotation froth through nozzles at the end of vertical pipes which are suspended from a header above the froth. This maximizes the effective cross sectional area of flotation vessels while maintaining effective froth cleaning and a desirably high density of the concentrate slurry. The plant tests gave increases of copper concentrate production rates of 17% to 20% for conventional cells and 16% to 20% in column flotation at target grades of 29% to 30% copper and of less than 0.5% nickel. Basic considerations and concepts of tests and evaluation procedures are described.IntroductionMeeting flotation concentrate grade targets at maximum production rates and recoveries is a challenge all too familiar to operators of base metal ore concentrators. Frothwashing is an option to improve grade/recovery performance by minimizing entrainment of impurities into the concentrate, which is commonly known since the sixties (Kaya & Laplante, 1989). It has been recommended for the flotation of sulphides and industrial minerals alike (Kaya & Laplante, 1989; Miller, 1969; Heinrich, 1989) and has found its ultimate application in flotation columns (Finch & Dobby, 1990). The washwater addition in a flotation column is most evenly distributed over the column's cross-sectional area thus ensuring almost complete displacement of feed water from the froth by a countercurrent washwater flow -provided, a positive bias is maintained. Therefore, flotation columns are ideal for cleaning flotation. However, there is usually less room for boosting the concentrate production capacity by increasing airflow or slurry level then with conventional cells because of the smaller cross-sectional area available."

Jan 1, 1994

"In the past year, mining at the Doyon Mine has shifted entirely from open pit to underground. The mine produced 234 692 ounces of gold in 1989 and is expected to produce 225000 ounces in 1990. The Doyon Mill has been running slightly above design capacity, and recovery has increased 3%.IntroductionThe Doyon Mine is located 25 miles east of Rouyn-Noranda, Quebec (Figure I).It is a joint venture owned by Lac Minerals and Cambior, with each holding a 50% interest. Lac Minerals operates the mine under the direction of a management committee.Production at the Doyon Mine began in 1980 with the start up of the Main Zone pit. Shortly thereafter the Doyon Mine became the largest open pit gold producer in Canada.In 1983, a ramp leading to the fourth level and exploration drifts were driven. Results were very encouraging, therefore the decision was made to sink a 2150-foot deep shaft, which was completed in 1986.In mid-1986, production began in the West pit, while underground mining of the West Zone started shortly thereafter, at the end of the same year.In 1987 the mill capacity was increased to 3300 tons per day and the Main Zone underground operations commenced."

Jan 1, 1990

By C. V. Corless

THE origin of various types and groups of ore deposits was some years ago a subject of much controversy. To this statement the copper-nickel deposits near Sudbury afforded no exception. Not since the Report of the Ontario Nickel Commission, in 1917, has there been any serious discussion of the origin of this very important group. This may be because, from the opening-up of Murray mine by the British America Nickel Corporation until the recent work at Frood mine, no new ore-body of importance has been developed in the district. The controversy fifteen or twenty years ago between those who favoured the theory of magmatic segregation, among whom Dr. A. P. Coleman was the leading exponent, and those who considered that most, if not all of the Sudbury deposits could more satisfactorily be accounted for by the theory of replacement, will be remembered by many members of the Institute. Perhaps, as too often happens in controversial discussion, each side tended to overemphasize the importance of those geological phenomena which seemed to be most easily accounted for by the theory it favoured. A more balanced view would perhaps admit that replacement was probably predominant in the formation of most of the offset deposits, and magmatic segregation in that of most of the marginal deposits . But there is danger in generalization. Each body of ore should be studied by itself, and no general conclusion of this kind should be allowed to warp the judgment in making such a study.

Jan 1, 1929

By Miguel A. Cuba

Resource models are generally constructed using data of different types and/or from different sources. A common issue is the consistency of scale in the information that often leads to a requirement to composite the data prior to model construction. For the purposes of mine planning, development and/or resource assessment, this model may then be upscaled to a relevant selective mining unit. It is well established that the geostatistical parameters for resource model construction is scale dependent. In particular, the volume variance of integrating these various scales has a direct impact on the variogram that should be used in model construction and/or the assessment of volume variance relations as it affects resource estimation. The scaling laws are a set of guidelines that detail how the variogram should change as a result of a change in the volume; these laws are empirically derived and involve some simplifying assumptions, not the least of which is an assumption of shape invariance in the variogram structure. An alternative approach was proposed to directly upscale the variogram via numerical integration, which demonstrates that the assumption of shape invariance is not required and we can directly access the new variogram shape given any volume of interest. This paper compares these two different approaches to variogram upscaling by considering two applications: the first corresponds to a 2D synthetic case and the second looks at a 3D case with data from a porphyry copper deposit. The simulation studies in these cases show that the direct upscaling approach performs better than the scaling laws in fitting the average experimental variogram values at any block size. This is based on a mean absolute error criterion. Moreover, it is also shown that with an increase in the block size, direct variogram upscaling significantly outperforms the scaling laws approach.

Oct 1, 2009

By G. W. H. Norman

The surficial Archæan rocks of the southern gold belt of western Quebec are constricted near Kewagama lake by granite masses to the north and south. This divides the belt into natural eastern and western parts. This paper deals with the eastern part, extending from Malanie to Haig township. In this section the Keewatin-Timiskaming rocks have a length of about 70 miles and end abruptly against garnetiferous gneisses of the Grenville terrain. In the western half of the section where exploration has been under way since the early twenties, there are sixteen mines that are or have been in operation, and eleven prospective mines. In the eastern half where exploration has been carried on since the early thirties, six prospective gold mines are under development, one· of which, Louvicourt Goldfields, is at the initial production stage. Of the sixteen properties in the western half that are operating or have operated, all, except the Golden Manitou, which is a base metal mine, and the old Green Stabell from which there was a small production of copper, produce gold. Of the eleven prospective mines in the western half nine have gold. New Bidlamaque has gold and copper and one, East Sullivan, has copper-zinc ore. Since production began in 1927 gold, silver, zinc, copper, and lead having a total value of about $10,000,000 have been produced from the mines of the eastern section of the southern gold belt of western Quebec.

Jan 1, 1954

By Robert B. Parsons

"The customary onslaught of government budgets this spring offers lots of interesting reading to the mining industry.While the favourable changes tend to get all the fanfare, there are some ""sleepers"" in the host of proposed changes which will be bitter pills for some mining people to swallow.IntroductionOn a scale of one to ten, the Canadian mining industry will probably give this year's federal and provincial budgets a score that is pretty close to five. Although some budgetary proposals are generally perceived to be favourable to the industry, there are other provisions (and lack of provisions) which are considered to be negative.This month, Tax Notes examines in a summary manner the principal features of the 1985 federal and provincial budgets which are of particular interest to this country's mineral industry."

Jan 1, 1985

By W. A. Alexander

Introduction In the course of a programme of research on beryllium in progress in these laboratories, knowledge of the recrystallization temperature became necessary. As the information is not available in the literature, the determination of this temperature for metallic beryllium was undertaken. By the reduction of grain size through working and recrystallization and the probable simultaneous induction of preferred orientation, it was hoped to improve the working properties of beryllium at lower temperatures. The recrystallization temperature is usually determined by observing the lowest temperature of annealing at which new crystals are formed in severely cold-worked metal or alloys. This temperature is profoundly influenced by the following factors: the purity of the metal, in the case of an element, or the composition of the alloy; the degree of straining or working; the temperature of straining; the original grain size; and the time held at the annealing temperature. The observed temperature is lowered by higher purity, more severe straining, lower temperature of working, smaller original grain size, and longer time of annealing. Beryllium presents special difficulties in that the percent elongation in tension is effectively zero, so that ordinary squeezing or rolling was not possible. A possible means of straining was suggested by the fact that indentation hardness tests could be made. It was known from earlier work that the metal could be worked at elevated temperatures, so that working at the lowest feasible temperature and quenching might also be a means of producing strain. The purity of the metal is also a point of some uncertainty in the case of beryllium. Losano has prepared 99.96% Be which appears to be the best reported. Distilled metal used in the present work approached this purity. However, by analogy with other metals, residual impurities may have a pronounced effect on the recrystallization. Further purification of beryllium would evidently entail considerable difficulties due to the highly reactive nature of the metal, and was not attempted.

Jan 1, 1947

By F. Q. Barnes

"Uranium, thorium and yttrium have been recovered, since the 1950s, from pyritic quartz-pebble conglomerates occurring in the basal sediments of the Quirke syncline at Elliot Lake. Gold, an element of interest in similar type deposits occurring worldwide, is a very minor constituent of the Elliot Lake conglomerates because the provenance area of the sediments had few gold-bearing rocks.Uranium, thorium and rare elements are found in resistate and diagenetic minerals occurring in the matrix of the conglomerates. The valuable elements are recovered from the acid soluble minerals during the milling process.Large uranium reserves occur in mines found on both limbs of the Quirke syncline. Major reserves are being developed on the South Limb of the syncline, where the Stanleigh Mine, among four past-producers, has been reactivated.IntroductionUranium and thorium commonly occur in anomalous amounts in coarse basal sediments. Radioactivity in basal conglomeratic sediments is generally attributable to resistate minerals, that rarely occur in concentrations high enough to be of economic significance. One type of basal conglomerate found worldwide, in Precambrian cratonic basins, has uranium or uranium and gold concentrations large enough to be of economic interest. Principal among the occurrences are the pyritic quartz-pebble conglomerates of the Huronian in Canada, of the Witwatersrand in South Africa and at Jacobina in Brazil.The uranium and gold mineralization of these conglomerates was derived from provenance areas where both elements occurred and were later concentrated through source degradation and deposition in placers in a reducing environment. Only the Huronian conglomerates, generally much richer in uranium but with negligible gold, have been exploited solely for their uranium content.The uraniferous conglomerates of the Huronian at Elliot Lake, 500 km north of Toronto, continue to represent a major world source and supply of uranium concentrate."

Jan 1, 1986

By Jean-Luc Collins

"This paper shows how simple reliability concepts such as mean time between failures and mean repair time can be used efficiently to help increase equipment availability and so reduce the economic losses associated with unreliability.More specifically, the paper shows how these simple concepts can be used in maintaining an appropriate balance between fleet failure and repair rates and how they can be used for setting up priority repair rules f or queuing equipment.IntroductionA profitable mining operation must handle large quantities of ore and waste at the lowest possible cost. To achieve this objective, the operation must optimize the productivity of its fleets of equipment by efficient management of the time element. Figure I shows some basic equipment activities in an open pit operation while Figure 2 shows a tree diagram describing some time elements of these activities.It should be noted that the only time a piece of equipment can generate a profit is when it can be found in the operating status. In order to maximize this time element, the sum of the other time elements must be minimized because the total time is always fixed.This paper shows the application of simple techniques capable of reducing the waiting time for repair (maintenance delay) by using simple reliability concepts."

Jan 1, 1988

By Bill Dupley

We believe that the inability of employees to effectively manage information has reached an epidemic problem throughout the corporate world. ? All the available knowledge in the world is accelerating at a phenomenal rate. ? The whole world's codified knowledge base (all historical information in library books and electronic files) doubled every 30 years in the early 20th century. ? By the 1970s, the world's knowledge base doubled every seven years. ? Information researchers predict that by the year 2010, all the world's codified knowledge will double every 11 hours.

May 1, 2003

By Mariam Melashvili, Chris Fleming, Rene Jackman

"A study was undertaken to develop a flowsheet for treating a high grade silver/gold ore body by cyanidation, CCD and Merrill Crowe precipitation, with tailings detoxification to meet stringent limits for cyanide and thiocyanate concentrations in the final discharge. In one of the flowsheets examined, free cyanide in the final leach liquor was recycled to the mill where it was hoped that it might react beneficially with fresh ore to reduce the cyanide makeup by an equivalent amount. However, laboratory results suggested that most of the cyanide recycled to the mill reacted with iron forming a soluble ferrocyanide complex. This would have had a negative impact on cost, not only because the cyanide recycled to the mill could not be claimed as a credit, but also because the presence of ferrocyanide in the final tailings meant copper sulphate had to be added to the SO2/air cyanide detoxification process to precipitate the iron cyanide. In an alternative flowsheet that was examined, recycling of cyanide to the mill was abandoned, and this allowed the milled slurry to be pre-aerated in a single mixing tank before cyanidation. During alkaline pre-aeration, any ferrous ions that are generated in the mill are oxidized to ferric ions, which, unlike ferrous ions, are inert in cyanide solution. This significantly reduced cyanide consumption and lowered costs in the detoxification of the tailings. In this paper, the cost implication of these two circuits is compared.INTRODUCTIONMost of the gold that is produced by hydrometallurgical processes is recovered by cyanide leaching. The reason for that lies in the superior thermodynamic stability of the gold cyanide complex and the favorable economics this confers on the process (Fleming, 2014). However, the gold in most of the gold-bearing ores processed is a very minor component, and therefore, the leaching response is often dominated by that of the host minerals.Many gold ores treated by the cyanidation process contain iron minerals. Cyanide reacts readily with some iron minerals forming ferrocyanide as one of the compounds. Ferrocyanide is stable when solutions are exposed to air and does not retard the dissolution of gold. In fact, it has been claimed that potassium ferrocyanide in the presence of oxygen is a weak solvent for gold (Hedley & Tabachnick, 1958). The main problem with the formation of this compound is the consumption of cyanide. Ferrocyanide contains six molecules of cyanide for each atom of iron {Fe(CN)64-} so the wasteful consumption of cyanide is greatly increased by its presence. Thiocyanate is also often produced during the reaction of certain iron sulphide minerals with cyanide, and contributes to the wasteful consumption of cyanide. In addition, environmental regulations in certain countries demand that thiocyanate be removed from the tailings, and this adds significantly to the cost of tailings treatment."

Jan 1, 2016

By Seunghoon Lee

The increase in the number of higher and larger buildings is expected to require the buildings' outer wall maintenance process, which includes cleaning, painting and monitoring, still depends on manpower. In this study, we proposed the robotic building maintenance system and aimed to reduce the jerk effect through the motion control of the system, improve the performance of the maintenance task, and ensure longer life and safety by improving the stability of the building structure and robot system. Through the results of the motion control and field-test with the proposed system, in specific, horizontal sliding module (HSM) showed that the jerk oriented by impact force was significantly reduced, feasibility of the proposed method was verified, and the robotic challenges were explored.

Aug 1, 2013

By J. Bardinas

"The use of autogenous mills has become widespread, owing to their capacity and favorable capital and operating costs. Optimal operation of these systems is critical, given their high energy consumption and effect on downstream processing. A considerable effort has been spent over the years in the development of advanced control systems to achieve a better performance in this regard. However, despite significant advances, the problem still remains challenging, owing to the nonlinear behaviour of the system with respect to the mill variables, and, the unmeasured ore variability come from the mine.The mill load, in particular, can be seen as a state variable of the mill, which could be important for; modelling and control, and, important insights into the mill behaviour. In this investigation, time series cluster analysis was performed using online mill load measurements in order to identify the different control states of the mill. More specifically, this time series was divided into short non-overlapping segments. A distance matrix was set up for each segment and the information was captured by means of textural features, similar to that used in multivariate image analysis. These wavelet and grey level cooccurrence matrix features could subsequently be used to rapidly identify the normal operating conditions from the feed disturbances in the mill.In principle, the methods and models presented here, once suitably validated and calibrated, could be used in online process monitoring of autogenous mills. They also could serve as a foundation for developing more advanced process control models."

Jan 1, 2016