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By Mauro Chiesa

A. New Dictionary, Since 2007/8 Traditional concept of ?cycle? is dead A dearth of projects AND good metal prices suggests otherwise In a depletion-business, good times for any greenfields in 2-3 yrs! ?Balance? sheet means quality assets = quality capital So, de-risk the assets, and ration the capital ?Replacement costs > historical costs ?Discounted assets depleting; replacement costs need self-financing (FCF) ?Public-sector slows permits, avoids assets and wants more of FCF ?Capital ?markets? are now ?market fragments? ..and? ??Shareholder? has changed from ?growth? to ?income + performance? ?Higher search costs, higher capital costs and higher cost of capital

May 1, 2013

By The Staff

This is in direct contradiction to the generally accepted philosophy of tube-mill grinding, which is based upon an enormous amount of experiment carried on in different parts of the world. Personally, I have no faith in the reliability of these conclusions of the authors. (Incidentally, the two circuits compared consist of six mills each of which the change in the hook-up is only in the last three mills-in one case, these three mills are in closed circuit and in the other, open or series circuit. Hence the last three mills are alone responsible for the alleged improvement, which means that the improvement in these three mills amounts to at least 18.8 per cent). The value of these figures depends upon the reliability of the work, of the measurements and the calculations of the authors. As very little information is contained in this Addendum concerning the methods of the work and the details of the measurements, it is necessary, in order to form an estimate of this reliability, to study carefully the previous paper published in the July, 1940, BULLETIN(3). Referring to the original paper, the present paper has this to say (bottom of page 379): "Here it may be remarked that we have made more money for Lake Shore digging into and forming the report than in obtaining the figures and data, and so far have never gone back to work on it without a resulting Lake Shore profit". Let me state that I, so far, have never gone back to work on it without finding more discrepancies and inconsistencies and illogical reasoning. In my first contribution to the discussion of the first paper, which discussion was published on page 355 and following, in the July, 1941, BULLETIN, I pointed out discrepancies and inconsistencies and illogical reasoning.

Jan 1, 1942

By M. H. Allan

SASKATCHEWAN POWER CORPORATION is a Provincial Crown Corporation responsible for the production transmission and distribution of electric power and natural gas in the Province of Saskatchewan. Through the electric power responsibility, we became interested in the coal reserves in Saskatchewan, which, although still somewhat of an "orphan fuel" in the early and mid 1950's, gave the promise of providing a low-cost source of energy for electric generation. Coal in Saskatchewan, a lignite with an "as-received" heating value of from 5000 to 6500 Btu's per lb and up to 40% moisture, was first recorded in 1853 . By the end of the 19th century, many small mines were in operation in the Estevan, Coronach and Shaunavon areas supplying local inhabitants with a cheap source of heat. These small mines, some of them prosperous, some of them not, continued operation right up to the late 1940's, when oil replaced coal in the market place. The year 1930, however, saw the introduction of the new technique of strip mining in the Estevan area. This technique revolutionized coal mining. It was now possible to use large machinery to uncover the coal and cast the overburden to one side instead of burrowing through thin seams of coal varying from 2 to 10 feet thick. The overburden cast aside by these large mechanical shovels, or later draglines, created heaps of spoil which at that time, during the depression, were a sure sign of prosperity and the welcome news that people had jobs. By the late 1940's, coal production had dropped off, but the spoil piles remained and were now labelled by some as "scars on the landscape", even though there had been some natural succession of grasses. In addition, some people had planted trees in experimental plots and even some aerial seeding had been done.

Jan 1, 1978

By J. E. Gill, A. R. Byers

The Surf and Pugsley gold-copper mines; owned and operated by Surf Inlet Consolidated Gold Mines; Limited; are about 6 miles inland from; the head of Surf inlet; on Princess Royal island; Skeena mining division; British Columbia. Surf inlet is a fiord 360 miles in an air line northwest of; Vancouver.

Jan 1, 1954

By H. Clare Horwood

"Three types of structures, the main shear zone, the north shear zone, and a series of hanging-wall fractures, contain all the orebodies so far discovered at the McKenzie Red Lake mine. Lenses and veins of quartz in these zones and fractures are the sources of the ore. The ore-bearing structures are unusual in that they are in a complex intrusive mass known as the McKenzie-Gold Eagle stock. They are believed to have been produced by compressive stresses from the south andsouthwest.The mine is on the northeast side of McKenzie island, in Dome township in the central part of the Red Lake area. The original discovery, the main shear zone, was made in 1928, about 3 years after the property was staked, by M. L. Bouzan who was in charge of prospecting and development work on the property. Subsequent diamond drilling and underground exploration led to the installation of a mill, which came into production early in 1935. The hanging-wall fractures were found branching out from the main shear zone during development work on the 350-foot level. The north shear zone was discovered in 1940.From 1935 when the mill began operation until the end of 1946 total production from the mine was approximately 269,349 oz. gold and 69,317 oz. silver, having a value of $9,679,739, recovered from 823,527 tons of ore.GENERAL GEOLOGYThe McKenzie-Gold Eagle stock has a total length of approximately 1 ½ miles and a width of about ½ mile. It was intruded into a complex synclinal fold in Timiskaming sediments. The sediments, which have been cut in only one place in the underground workings, are principally wellbedded greywackes. The stock is composed of large masses of diorite and granodiorite, a small mass of hornblende pyroxenite, and basic dykes of two ages. The diorite occurs as irregular masses in large measure surrounded by the granodiorite that it intrudes. It contains tabular crystals of andesine, having a maximum length of3/4 inch. The hornblende pyroxenite is an elongated lens or dyke in the diorite. The granodiorite masses occupy about two-thirds of the stock. Along its eastern side the main mass tends to become darker and more dioritic toward the diorite contact.Basic dykes of pre-vein and post-vein age are the youngest intrusive rocks at the mine."

Jan 1, 1954

By J. Fox, K. Kocsis

"Planning for sustainable cooling potential requires protected space to successfully maintain chilled propylene glycol in storage until needed. Stored propylene glycol should be judiciously cared for, safely kept from the ill effects of heat, in order to remain useful for bulk air cooling. Minimizing the chilled temperature of the propylene glycol reservoir tanks means that atmospheric conditions will be monitored closely during the chilling phase. Storage facilities would maintain restricted airflow while minimizing possibilities for heat transfer during the storage phase. Sustainable cooling systems could reduce or eliminate the need for mechanical cooling if installed with favorable conditions. Storing the cooling potential from the winter months is what this new design is all about.INTRODUCTIONIn most subsurface, bulk air-cooling methods, the main source of potential cooling energy comes from cold-water applications. This paper investigates the practical use of harvested, chilled propylene glycol as the source of cooling potential. Propylene glycol is chosen as the cooling storage liquid refrigerant since its chemical make-up is intrinsically safe to fresh water supplies and will not harm underground workers should a leak occur in the closed cooling circuit. Harvesting the cold of winter is a meaningless endeavor without proper thermal planning for the storage of the cooling potential in cold refrigerant.PROPYLENE GLYCOL STORAGE RESERVOIRA new design for a closed refrigerant bulk air cooling system employing propylene glycol as the refrigerant is presented as the main design topic of this paper. Given that a deep and hot mine will need to be considered safe and productive, a cost-effective cooling system is desired in order for the mining operation to be considered sustainable. For underground mines at northern latitudes, cooling applied to fresh air is only required 3 to 4 months of the year. During winter, ambient atmospheric conditions can be harnessed and stored for use at a later time.The basis of this sustainable design uses very cold ambient air that is circulated around galvanized steel refrigerant reservoir tanks. The propylene glycol reservoir tanks are arranged in a concrete walled pit, or tank farm, excavated in bedrock. During the coldest months, the tank farm will be exposed to the open air. As the seasons change the tank farm will be covered with insulation to maintain the maximum cooling potential for use during the warmest months of the year."

Jan 1, 2019

By Mustafa Kumral

Monte ? Carlo simulation is often used to assess the risks associated with uncertain variables in mining operations. The success of Monte-Carlo simulations depends upon reproducing the dependencies among variables to some extent. However, some variables may exhibit different dependency patterns. In these cases, classical techniques for dependency quantification cannot capture dependencies. As an alternative, the copulas allow modeling nonlinear dependencies. Furthermore, any choice of marginal distributions can be used. Especially, for the data, which is sensitive to extreme case such as financial crisis, the copulas arise as a means to reproduce the correlations among variables. In this paper, the copulas are introduced to mining practitioners using Monte-Carlo simulations for risk assessment. Then, a case study is given to show the superiority of the copulas over classical techniques using ModelRisk Software. In conclusion, it was observed that the copulas enhance the quality of Monte-Carlo simulations by capturing variable dependencies.

Aug 1, 2013

By W. D. Robbson

DR. G. W. RAMSEY (l): A study of our non-treatment silicosis autopsy material for the years 1940-43 inclusive, in addition to the common findings of fibrosis, nodules, and emphysema, shows marked thickening of the alveolar walls. This change is due to one or more of the following factors: congestion, edema, accumulation of both small and large monocuclear cells within the interstitial tissues and large monocuclear cells attached to the lining membrane of the alveolar sacs. This alteration in the alveolar walls, we believe, is one of the most important factors in producing impaired pulmonary function. Comparison of our first autopsy material of a case receiving twenty aluminium treatments beginning June, 1943, shows a striking change in the alveolar walls. In all areas free of silocotic nodules and fibrous tissue, the alveolar walls approach normal thickness and are free of cellular deposits. No change was noted in the old processes and none was expected. We believe that these changes in the alveolar walls were brought about by the aluminium therapy and that they constitute a major factor in the improved pulmonary ventilation noted in treatment cases.

Jan 1, 1945

By A. G. Pentland

MODELS of mines may be classified under three headings: (a) sheet models, (b) solid models, and (c) skeleton models. Sheet Models are made of sheets of glass, celluloid, or a transparent plastic material. The sheets are mounted in a frame which holds them in a parallel position, either horizontally or vertically. Mine plans are traced on the horizontal sheets; sections on the vertical sheets. The model may be illuminated by electric lights which are separated from the sheets by an opalescent screen. It is viewed from above or from the side in such a way that the plans or sections are superimposed. Sheet models are very useful for the illustration of mines with narrow, steep-dipping veins, but they do not give a satisfactory representation of a large mine with a flat-dipping vein. Large sheets of glass are difficult to handle and to support in a frame.? It is difficult to see through a considerable number of them. Solid Models are made of plaster, concrete, wood, or other material usually in the form of slabs in which the mine workings are indicated by properly dimensioned cavities in the model. The slabs are coloured to show the veins, country rock, faults, etc. The model is divided along selected sections in order to give access to the interior by the temporary removal of parts. Solid models may be used to illustrate large orebodies of the Sullivan type, but they are cumbersome because parts must be removed to study details of structure. Skeleton Models are ones in which the underground cavities are represented by metal, wood, plaster, or wax proportionately shaped and held in place by a frame. They illustrate the work which has been done but do not show the position of the veins, dykes, faults, etc., in the unworked parts. It is necessary to project by eye between workings in order to determine the location of these features. The essential difference between the skeleton model and the solid model is that the skeleton model represents the mine workings by solid forms and does not show the unworked parts of the vein, whereas the solid model shows the vein as a solid and the mine workings as cavities in it. The skeleton model lends itself well to the representation of a large mine with large stopes.

Jan 1, 1944

By M. K. Senicie

IN July, 1937, Asbestos Corporation, Limited, installed an automatic conveyor-belt scale at their King mine, Thetford Mines. The equipment was purchased 'on trial' and its performance has proved entirely satisfactory to the staff. The scale was manufactured by the Toledo Scale Company, of Toledo (Ohio) and Windsor (Ont.) and was installed by one of the Scale Company's engineers. The electrical recording equipment was installed by Keith Mercer, Reg'd, of Montreal, Canadian agents for the manufacturers, the Builders Iron Foundry, of Providence, Rhode Island. The recording equipment consists of a duplex weight-transmitter attached to the scale-head, a duplex totalizer with differential relays, a belt-speed compensator, a rate-of-delivery recorder, and a rate-of-delivery indicator. As it was desired to run the mill at maximum capacity, it was necessary to know the rate of feed at all times, so that any lessening of rate of feed or delays would be recorded and could be corrected. After having determined the rate of feed to the mill (100 per cent capacity), it was required to have weighing and recording instruments which would show: (1) The rate of feed per hour. (2) Any variations .in the load. (3) Any delays and the duration and time of the delays. Rate of tonnage recorders in the mill superintendent's office and at the point of feedi.ng were necessary, as was automatic control between the mill superintendent and the feed man. It was desired to have a permanent record of total tonnage fed per shift or day; weighing and recording mechanism had to have sensitivity to record all previously mentioned conditions. Mechanism had to be of rugged construction, and be so built that it would stay in good operating condition, with the minimum amount of adjustment and supervision.

Jan 1, 1938

By J. A. Orr

The details connected with the mining and subsequent handling of Creighton ore were fully covered in a paper presented to the Institute in 1920. The following brief notes describe certain phases of the present practice and show wherein it differs from the practice at that time. These may be summarized under the following headings. (a) Recovery of pillars. (b) Drawing the ore. (c) Change from sub-level tramming to branch-raise system. (d) Chute construction. The present stoping practice is the same as formerly, i.e., fiat-backed shrinkage stopes of 60-foot width, between rib pillars of 15-foot width, extending from the footwall to the hanging-wall. Formerly, when these stopes were completed to the stopes above, they were drawn empty of broken ore, and the 15-foot rib pillars were caved into the stopes and drawn off through the same chutes as were used to draw the ore from the stopes.

Jan 1, 1926

By R. Heikkilä

As a part of a large research and development program in Finland, a system calibration for an UAV measurement method having practical experiments in a Jorvas Railway Yard design and construction project. The Railway yard construction are was measured using an UAV measurement device by Smartplanes (Smartone) and using some reference points measured by a GNSS device. The measured data was cleaned, combined and adjusted through Least Squares Optimization using the software developed by a Finnish company Pieneering Oy. As references, two different laser scans as well as total station surveys were used. For applicability evaluation, the accuracy of measurement, the reliability of measurement, and the economy of measurement were used. Based on the comparisons, the achieved precision of the UAV measurement was high, instead the accuracy of measurement was not sufficient in this case. The principle of this photogrammetric measurement includes a lot of redundant observations making it possible to achieve a high level of reliability. The economy in this Railway Yard Design project was not able to achieve.

Aug 1, 2013

By Robert B. Parsons

"On August 8, 1989, the Minister of Finance released a technical paper which sets out many of the details of a proposed 9% federal value-added tax to be called the ""Goods and Services Tax"". The GST, which is scheduled to be implemented with effect from January 1, 1991, will affect all Canadians in different ways and to varying degrees. The mining industry itself should, by and large, benefit from the new tax.IntroductionOn January 1, 1991, it is proposed that the existing federal sales tax will be replaced by a new sales tax - the Goods and Services Tax (GST). GST will be leviedat a rate of 9% on most goods and services consumed in Canada.How it will WorkThe GST will be a tax on the final consumption of goods and services. It differs from a retail sales tax in that it will be collected throughout the production and distribution chain. However, the net effect of the tax paid on a particular good or service will be equivalent. The example above (next column) illustrates the application of the GST to the production and sale of a chair.Illustration of GST for a ChairEssentially, the total tax will equal 9% of the sale price to the final consumer. However, GST will be collected on the value added at each stage of the production and distribution chain . What will be TaxedVirtually all goods and services will be taxed. Items on which GST will not be charged fall into two categories: tax free and tax exempt."

Jan 1, 1989

By L. H. Thorleifson

Demand for both gem and industrial diamonds is very strong. Synthetic production supplies industrial uses, but synthetic gems remain inferior and expensive, so the large gem market is supplied by mining. Several major mines have been depleted, and the market is receptive to new sources of high quality gems. Canada's Precambrian terrane, extending across the Canadian Shield and under the Phanerozoic cover of the Plains and Hudson Bay, has excellent potential for diamonds, but exploration conditions are difficult due to recent glaciation. Early world exploration relying on recognition of diamond in alluvial sediments was adequate to launch pre-1900 production from India, Brazil, and Africa. Exploration success in Canada, as was the case in Russia and other more recently discovered sources, however, had to await large investments in effort supported by advanced science and technology. Canadian exploration in many ways is similar to that in other regions, relying on analysis of tectonics, indicator minerals, geophysical surveys, and multiple stages of drilling and sampling. Very different from other regions, however, is Canada's surficial environment, in which recent glaciation has caused fresh indicator minerals to be transported hundreds of km. Exploration accelerated in Canada after 1960, first in Ontario and the Arctic Islands, then in Saskatchewan in 1988, and most importantly after the Chuck Fipke - Stew Blusson discovery at Lac de Gras, Northwest Territories, in 1991 that led to the billion-dollar BHP - Dia Met Ekati Mine that opened in 1998. In 2003, production from Ekati is expected to be supplemented by that from the similar and nearby Diavik Mine of Rio Tinto and Aber, currently under construction. These mines will bring Canadian output to over 10% of world supply, and will position Canada with Botswana and Russia as world leaders in production of high quality gem diamonds. There could be other mines as well, as sites across the Arctic and in the south from Alberta to Québec are being explored by an array of companies, including De Beers, other majors, and several juniors.

May 1, 2001

By J F. Davies

A review is presented of the fundamental differences between the Superior and Churchill geologic provinces. Structure, lithology, grade of metamorphism and a single recent age determination suggest that the Flin Flon -Snow Lake and Lynn Lake belts are remnant blocks of originally Superior rocks lying within the Churchill province. Major mineral belts occur along the main boundary between the Superior and Churchill provinces (the Thompson -Moak Lake nickel belt) and within the remnant Superior blocks inside the Churchill province (Fiin Flon -Snow Lake and Lynn Lake). During the Hudsonian orogeny, metamorphic gradients must have existed across the Churchill-Superior boundary and between the remnants of Superior rocks and the enclosing gneisses of the Churchill province. It is possible that not only the unusual nickel deposits of the Thompson belt but also the base metal deposits of the Flin Flon -Snow Lake and Lynn Lake districts are due to redistribution, or diffusion and migration of metals to areas of lower-grade metamorphism during the Hudsonian orogeny.

Jan 1, 1964

By K. Matsuura, M. Ohno, T. Tokunaga

"Recently, weight saving of automobiles has been strongly required to solve the global environmental problems. Mg alloys are one of the promising candidates as a new material for automobile components. However, the application of the Mg alloys is limited due to their poor corrosion resistance. In the authors’ preliminary study, an Al/Mg/Al clad sheet was fabricated by hot extrusion and subsequent hot forging. The clad sheet exhibited a high corrosion resistance and excellent super plasticity. More specifically, the elongation of the clad sheet was as high as 550%.Importantly, despite that the elongation of Al itself was only 40%without cladding with Mg, the ductility of Al was greatly improved in the form of the clad sheet. In the present study, in order to clarify the mechanism of the superplastic deformation of the Al part in the clad sheet, the microstructure evolution of the Al during the tensile de formation is investigated. The tensile tests were conducted at a temperature of 573 K and at a strain rateof1.0×10-3s-1. The Al exhibited fiber-type texture at the beginning of the tensile deformation, and brass-type texture after the elongation of 50%.INTRODUCTIONMg alloys have been gaining attention because of their excellent properties e.g. light weight, good recyclability and high electromagnetic shielding. However, their practical applications have been limited due to their poor corrosion resistance. In the authors’ previous study, in order to solve this problem, Al coating on Mg alloy by hot extrusion has been proposed, and the Al-coated Mg alloy plate was fabricated(Tokunaga, Matsuura, &Ohno,2012). The plate was hot-rolled and an Al/Mg/Al clad sheet was fabricated. No cracks or debondings were observed at the Al/Mg interface. The sheet exhibited a high corrosion resistance in a comparable level as pure Al. Also, the sheet exhibited a large and uniform elongation of 550%in a tensile test at a temperature of 573 K and at a strain rate of 1.0×10-3s-1without any breakings or debondings of the Al part(Tokunaga, Matsuura, &Ohno,2014).Mg alloys have been known to exhibit a superplastic characteristic when the grain size is small. However, it is known that the pure Al does not generally exhibit the super plasticity. As mentioned above, the Al-coated Mg alloy sheet exhibited 550% of elongation in the authors’ previous study (Tokunagaet al., 2014). However, the pure Al itself showed only 40% of elongation, while the Mg alloy itself exhibited 800% of elongation. Thus, it has been demonstrated that the pure Al was super plastically elongated when it was bonded with the Mg alloy. Generally, deformation mechanism of the super plasticity of the Mg alloy is known as a grain boundary sliding. On the other hand, the mechanism of the superplastic elongation of the pure Al is still unclear. The purpose of the present study is investigation of the deformation behavior of the Al part in the Al/Mg/Al clad sheet during tensile de formation."

Jan 1, 2018

By A. L. Irwin

THE disposal of tailing or waste material, which is generally a very large proportion of the ore treated, is a major problem in the location and operation of any concentrating enterprise and especially so where the life of the operation is expected to continue for many years. Many factors need to be taken into consideration in the selection of a tailing site, chief among which are economical handling of the material, subsequent re-treatment of the tailing, and precaution against stream pollution by waste water. The final location of many mill sites bas been governed largely by the selection of a sui table area for tailing storage. The Sullivan concentrator of the Consolidated Mining and Smelting Company is situated about three miles from the Sullivan mine at Kimberley, B.C., and one of the deciding factors in its location at this distance from the mine was the availability of a suitable area in which tailing could be deposited. In view of the indicated long life of the property, a far-sighted policy bad to be adopted in the matter of tailing storage, for not only would it be necessary to accumulate a huge tonnage of finely ground material, but also reclamation for iron recovery at some future date bad to be considered. Some idea of the extent of the problem may be grasped when it is noted that, by the end of 1938, over 18,000,000 tons of tailing bad been impounded in an area of some 200 acres.

Jan 1, 1939

By J. W. Reynolds

This paper describes the function of the research and development department of a large mining organization and the benefits which can be derived over the years. Examples are given of work done in rock drilling, ventilation, noise control and the development of backfill stowing machinery.

Jan 1, 1970

By Hans Lundberg

Magnetic methods have been used for more than three hundred years in prospecting for magnetic ores. More recently magnetic methods have been used for finding salt domes and studying certain geological formations. A number of instruments have been developed and substantial improvements made as to their sensitiveness and accuracy. Papers and articles written on magnetic methods are generally elaborate and technical, and the average prospector finds it difficult to obtain the necessary information as to how to operate the simple magnetic instruments to the best advantage. The miner's compass, dip needle, and inclinator are, indeed, very useful instruments and are easy to handle, and a great deal of valuable information can be gained if the instrument is properly operated and the results correctly interpreted. The lack of knowledge of the fundamental principles, however, has caused a great deal of disappointment. Other and more elaborate geophysical methods have recently come into the limelight, and the prospectors seem to have lost a great deal of interest in the dip needle. This is much to be regretted, because magnetic methods have a particular field of use. The present article is an attempt to help the prospector regain interest in the magnetic instruments and to show the use and application of a simple magnetic survey. If the prospector expects some useful help in his work, he must, of course, know the instrument, know how to take the readings, and know how to plot and interpret the observations.

Jan 1, 1929

By David J. Forrester

Light metals, most commonly aluminum, magnesium and titanium, and alloys containing them, are used in many industrial applications where lightness, hardness, ductility and resistance to corrosion are needed. However, these metals and their alloys can be potential ignition sources in underground coal mines. There have been documented cases in the past where coal mine explosions have been attributed to firedamp/coal dust ignitions involving light metals or their alloys. When light metals and their alloys are brought into contact with oxygen bearing material, such as iron oxide (rust) in the presence of heat, then a "thermite" reaction can occur. This source of heat can be generated from frictional contact or from merely a glancing blow. This paper outlines the hazards associated with light alloys, how to address the hazard and regulatory aspects.

May 1, 2001