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By L. R. Plitt

A new simple correlation has been developed to evaluate the performance of classifiers. The new correlation has been tested on existing data from 150 different hydro-cyclone classification tests. It is shown that this model provides a meaningful improved method of mathematically describing the classification process.

Jan 1, 1971

By J. M. Turnbull

THE primary objective of the young graduate, after the war, will be to obtain a suitable position within the Industry, with adequate pay and opportunity to advance. The positions available to meet this demand will depend on the magnitude and organization of the industry. The size of the mining industry, in particular, will depend on a number of factors, including depletion; new discoveries of mineral deposits; beneficiation of new kinds of mineral deposits, based on research; technical improvements, also based on research, enabling the mining of lower grade deposits; and complex social factors. The organization of the industry will depend on its control and management, which may be greatly affected by social conditions and changes, and may include a wider or a narrower use of technical services. The corresponding training or qualifications of graduates, to meet these conditions, calls for a consideration of educational requirements and facilities in relation to the conditions that are likely to occur. Some forecast of the probable future of the Industry, after the war, based on consideration of. the above factors, is necessary as a basis of discussion, since the graduate must find his place in the industry of that time, and find his work in maintaining and improving it, within the existent social framework. Social factors are pressing and? important at present and their future impact is uncertain. In considering these, a few quotations and extracts may be in order. "A new economic order, based on free access to the sources of raw materials, means free use of the world's wealth by all civilized nations" (The Pope. Also advocated by Churchill and Roosevelt in the Atlantic Charter). "Every citizen should have a voice in the conduct of business or industry which is ?carried on by means of his labour" (Archbishop of Canterbury).

Jan 1, 1943

By A. G. Lylie

Introduction At the Britannia Mining and Smelting Company's mill, the equivalent of 2,500 to 2,800 pounds of copper sulphate crystals per day is made from copper which is precipitated from the mine-water. This copper sulphate is used in the mill for the recovery of sphalerite by2 flotation. From 1932 until 1936 it was produced by exposing the precipitate to air for thirty days and then dissolving the oxidized copper with dilute sulphuric acid. In 1936, the flotation of sphalerite was discontinued and, when it was resumed in 1947, steps were taken to try to improve the former method. The present paper outlines the way in which this was done, and describes the plant and procedure by which copper sulphate is now being made, and by means of which an appreciable saving is being effected. Aboratory Tests The previous work had established that the precipitate, which consists mainly of metallic copper, must be oxidized before the copper would dissolve in dilute sulphuric acid. Various methods for oxidizing it were tried but in the early laboratory work the only suitable one found was to heat the precipitate to 600°C. and hold it at this temperature for two hours. When this was done, approximately 90 per cent of the copper became soluble in .acid. This percentage was considered satisfactory for practical purposes, but the cost of roasting was prohibitive because only a small amount of roasted precipitate was required each day.

Jan 1, 1951

By James F. Archibald

A research effort has been undertaken, under WSIB sponsorship, to characterize the support capabilities of conventional and innovative spray-on lining materials for mitigating dynamic failure effects created by simulated rockbursts. Conventional spray support media, such as shotcrete and fibrecrete linings, and a variety of new spray-on lining materials (TSL?s), typically polymer-type thin coatings, were subjected to simulated rockburst influence. For baseline comparison, conventional rockbolt and boltand- mesh support products were also evaluated. Observation of lining performance was undertaken through completion of field scale support and rock detonation trials. Controlled blasting tests were conducted at the Queen?s University Explosives Laboratory to examine the effectiveness of the variety of surface coating agents for modifying dynamic rock spalling processes. All tests were performed upon largely undisturbed and homogeneous rock materials in highly repeatable fashion. Both conventional and innovative TSL-type surface lining materials were subjected to ?rockburst? exposure in rigorously-controlled blast trials. All blasts were observed seismically and photographically to provide detailed information concerning rock motion, surface fracturing, ejected fragment motion and support liner survivability characteristics. These material comparison trials were performed to assess the relative effectiveness of a wide range of currently-available area support techniques for suppressing hazards associated with dynamic rock ejection. The results of this study validates that thin, sprayon linings may be equally as effective, and often better, than conventional support materials at mitigating rockburst or like damage in highly stressed mine environments.

May 1, 2003

By Robert D. Brown, Robert B. Parsons

"The mining industry may have survived the October 28 federal budget relatively unscathed, but the same certainly cannot be said of the petroleum sector-and many mining men are left wondering if their industry will be the next one to be singled out for special attention, as federal and provincial governments seek additional revenues and pursue nationalistic or provincial policies.Higher taxes, higher prices, a potpourri of ""incentives"", and a -""Canadianization"" policy mark the principal features of the new National Energy Program released by the government along with Finance Minister MacEachen's budget address.This month, Tax Notes examines the federal budget. with appropriate emphasis on the National Energy Program and its possible future implications forthe Canadian resource industries.IntroductionMost of the Canadian mining industry (tar sands miners excepted) heaved a sigh of relief on the evening of October 28, 1980, as Finance Minister MacEachen confounded the prophets in his budget address by not raising personal or corporation taxes and by making only relatively modest changes in the general tax system. Instead, he concentrated on a sweeping new energy policy. Unfortunately for that important sector of Canada's mining industry which is involved in mining the country's vast tar sands reserves, either now or in the future, the National Energy Program that was introduced along with the budget 'has serious implications."

Jan 1, 1981

By Alessandro Navarra, Roberto Parra, Boyd Davis, Frank Mucciardi

A smelter scheduling algorithm has been developed, which allocates the oxygen production between the smelting furnace and the converter aisle, so as to maximize copper throughput. The algorithm is intended for daily operation planning, controlling the sequencing of the converter cycles, and the oxygen drawn by these cycles. In some cases, it may be worthwhile to decrease converter oxygen allocation in favour of the smelting furnaces. Thus, a better utilization of the oxygen plant can increase primary copper throughput by several percentage points. This principle is demonstrated through sample computations. The approach presented in this paper can be incorporated into smelter management software.

Jan 1, 2015

By Raymond S. Suglo

Increasing depths of mining coupled with the mechanization of most underground mining operations have led to growing complexities in the mine environments with the production of large amounts of gaseous and particulate contaminants. Over 100,000 lives have been lost due methane gas and dust explosions in coal mine workings in both the US and Canada since 1900 when the methane concentrations exceeded stipulated levels in some workings. There is therefore the need to constantly assess and evaluate the performance of the existing mine ventilation systems to maintain safe and acceptable mine environmental conditions in workings to meet the requirements of federal, state or provincial laws. This paper uses the results of continuous monitoring of methane concentrations conducted in selected development headings in coal mines in North America to assess the effectiveness of existing auxiliary ventilation systems in the control of methane gas concentrations in the headings. The results show that the average quantities of fresh air required to dilute, disperse and remove methane concentrations within set levels of one minute varied from 5.43 m3/s in Heading #11 (Condition 2) to 27.97 m3/s in Heading #10 (Condition 1) and this represented about 12 to 26% of the quantities required to dilute methane concentrations to safe levels within one minute under Condition 1 and 32 to 139% under Condition 2. The average dilution times in the headings studied were less than 8 minutes. The forcing efficiencies of the auxiliary systems in the headings studied ranged from poor to excellent implying that the auxiliary ventilation systems were capable of controlling the methane concentrations below statutory levels but may not be able to cope with large and unusual methane concentrations in the headings. This study is important to prevent methane gas and coal dust explosions in coal mines and thus avoid any loss of lives and property.

May 1, 2001

By P. R. A. Andrews, R. K. Collings

"There are more than thirty-five deposits or occurrences of celestite in Canada, chiefly in Newfoundland, Nova Scotia, New Brunswick, Ontario and British Columbia. Deposits of economic interest are the Lake Enon and MacRae deposits in the Loch Lomond district of Cape Breton Island, Nova Scotia. Two Cape Breton deposits were operated from 1969 to 1976 by Kaiser Celestite Mining Limited, which supplied an upgraded celestite concentrate to an associated strontium carbonate plant at Point Edward, near Sydney.The MacRae deposit is of current interest because of its possible development for strontium carbonate production using the ""black ash"" process. This process involves chemical leaching, rotary kiln calcining with petroleum coke, washing and treatment with carbon dioxide.Celestite is the basic material used in the manufacture of strontium chemicals, principally strontium oxide, carbonate, nitrate, chromate, chlorate, chloride, sulphide and phosphate. Strontium chemicals, in turn, are used in the manufacture of glass and ceramics, in pyrotechnic devices, in the production of strontium metal and in other metallurgical applications. Recently, strontium ferrites have been introduced into permanent ceramic magnets."

Jan 1, 1991

By B. Caldwell

"The CompanyCardinal River Coals is jointly owned by Luscar Ltd. and the Consolidated Coal Company of Canada (Consol). The Luscar mine is operated by Luscar Ltd. and is located 40 km south of Hinton near Cadomin, Alberta (Fig. 1). The plant sits on the old townsite of Luscar, Alberta, which was founded in order to develop the coal in 1912 (Fig. 2). Initially, the coal was mined by Luscar Ltd. for heating and steam generation and used quite heavily by the railways for their steam locomotives. In 1955, the mine was decommissioned as the demand for coal for tl1ese purposes had dropped off. In 1969, the mine was re-established by Cardinal River to provide metallurgical coking coal for its customers in Japan. The coal is mined from the 13m thick Jewel Seam by open pit methods at a 10 to 1 stripping ratio. The run-of-mine coal is then cleaned to meet customer demands.The PlantThe clean coal preparation facilities at Cardinal River were extended in 1980 in order to increase the feed rate from 450 t/h to 800 t/h. The extension is a separate plant which can be operated on its own or in parallel with the old plant. In addition, modifications have been made to the fine coal circuit (hydrocyclones added), the coarse refuse circuit, (refuse bucks replaced by a refuse conveyor which backfills a pit), and the fine refuse circuit (solid bowl refuse centrifuges, refuse classifying cyclones, and hydra-rake thickener no longer utilized) since the plant was built in 1969. The plant production of 3 M t per year with a yield of 78% is achieved by first screening and breaking the run-of-mine material to a top size of 1 ½ in. The feed is then slurried, sized, and processed in three different washing circuits. The washed coal is mechanically dewatered, thermally dried, and then stored in a 14 500 t capacity silo or on a 300 000 t stockpile. The fine refuse is thickened and pumped to the same pit to which the coarse refuse is being conveyed"

Jan 1, 2000

By Pierre Antoine Dhaiti, Gilbert Sergerie, Michel Dagbert, Jean-Maurice Brodeur

"Quality of iron ore is generally determined by several factors which can be correlated or independent. Among these f actors, we generally find per cent iron, silica, magnetite or hardness. Forecasting the short- and long-term fluctuations of these f actors in the future pit is an important feature of mine planning in these deposits. Computer simulation provides a realistic answer to these questions. It allows to generate values for the most important quality features of each shovel load with the proper correlations between them as well as between one load and the next being fully reproduced. Then different sampling schemes f or grade control or blending facilities can be examined on the simulated data. The mechanics of the simulation procedure and its potential applications are described in an example.IntroductionThe purpose of this paper is to illustrate the use of in-situ grade simulation in the planning o f the grade control in an iron ore min e. More precisely, given a production unit of given size, we need to know how many samples have to be collected in that unit so that we ca n recognize its grade with a reasonable precision. Conclusions that we would like to arrive at are of the type: with 4 blasthole samples we ca n get the iron grade of a 10,000 ton bloc k with less than a ± 2% Fe error 95% of the time.The approach t hat we take to solve this problem is simulation. We simulate the grade of samples and the grade of the block that contains these samples. We repeat the simulation for hundred s o f blocks. By comparing the sample grade with the block grade in each case, we determine the actual number o f blocks where the difference sample-bloc k is less than a given limit."

Jan 1, 1983

By W. A. Jones

THE estimation of the average value of gold ore involves many considerations, among them the correct sampling of the deposit, the dilution by waste, and the loss of high-grade fines. It is a common experience that, after all these factors have been evaluated, adjustment of the assays is necessary before satisfactory agreement between the calculated mine grade and the mill heads is obtained. In fact, at many mines the latter correction overshadows all others in the preparation of routine estimates. For this reason it is proposed to deal only with the mathematical treatment of mine assays and the problem of bringing estimates into conformity with the corrected mill heads. Mine assays differ from physical measurements because the range of values is very great and these are not symmetrically distributed above and below the average, there being fewer high than low results. There is no widely accepted mathematical procedure for determining the average of series of measurements which exhibit these characteristics. Customary practice consists in empirically reducing high assays until a satisfactory agreement with mill heads is reached. It was thought that more confidence could be placed in grade estimates if a logical basis for calculations could be devised .. In an attempt to find a fundamentally sound procedure, amenable to practical application, many series of assays comprising over 235,000 channel samples (1) were studied at Hollinger Consolidated Gold Mines, Limited. Such an investigation could only be made where records covering many years of operation are available and where tabulating and calculating machines are in use. The results are recorded in the hope that the relationships noted for the large groups of assays used are of fundamental character and that the data will be useful to others dealing with the problem of grade estimation.

Jan 1, 1943

By C. S. Ha, H. S. Choi, D. Y. Shin

POSCO installed a new 100 ton oxygen bottom-blown converter in 2013 for the development of new steelmaking process named as PS-BOP which is reading POSCO-Saarstahl Basic Oxygen Process. This process was developed by the collaboration research between POSCO and Saarstahl AG in Germany that is based on substantial increase of CO post combustion in a converter by blowing hot air from the top of converter. The collaboration research has been finished successfully in November 2013 with 17% decrease in hot metal ratio (HMR) when hot air was blown from the top of the oxygen bottom-blown converter. After the collaboration research the converter has been tried to be operated as oxygen top and bottom-blown converter to reduce bottom wear and to decrease production cost with increased use of low cost Fe source by the help of increased CO post combustion. The presentation includes experience on the start up of oxygen bottom-blown converter, HMR reduction trials with hot air top blowing and transition from oxygen bottom-blown to top and bottom-blown converter operation.

Jan 1, 2015

By A. Himsley, E. Byleveld

"With reference to the chemical constraints underlying the ion exchange process for uranium recovery, a generalized view is presented on the actual and the achievable efficiency of the process. The area considered is restricted to acid leach circuits in combination with nitrate, chloride or sulphuric acid elution.A comparison between actual plant results and the chemical requirements shows that:(a) Unless new and better ion exchange resins are developed, no dramatic change in equipment size and resin inventory is""anticipated. (b) Elution efficiency, especially for sulphuric acid, may be improved considerably. More concentrated eluates may beproduced at lower chemical consumption. A possibility of achieving additional purification solely by ion exchange is discussed.IntroductionThis paper presents a generalized view of the actual and the achievable efficiency of the ion exchange processes for urannium recovery. The study is restricted to acid leach circuits in combination with nitrate, chloride or sulphuric acid elution. The ultimate efficiency attainable with ion exchange is dietacted by the chemical reactions underlying the process. The most sophisticated technology cannot change the diffusion rates in the ion exchange resin nor make the uranium loading exceed its equilibrium valueThe design of an ion exchange plant for uranium recovery involves a considerable number of parameters as a result of the wide variety of pregnant solutions produced from different orebodies. Therefore, a generalized approach of the ion exchange process inevitably neglects some parameters which maylead to significant variations in apparently identical situations.The uranium concentration in the pregnant solution, together with its pH, are the principal variables which determine resin loading and residence rime in the ion exchange system. On the elution side, the type of eluant and its concentration will determine the contact time required and the amount of eluant needed to strip the resin. The temperature, the properties of the ion exchange resin, the total dissolved solids in the feed solution and the competing ions are other variables that affect the chemical performance; these, however, may be considered as a correction of the principal parameters if one is interested only in general trends."

Jan 1, 1980

By A. Valdivieso

Reducing accident rates keeps getting more and more complex as the usual tools enter a curve of diminishing results. Fortunately, nothing modifies behaviour in a stronger and wider way than having a robust safety culture. On the other hand, managing cultural change is difficult and the risk of back-fire is very high, especially if the workforce does not trust our intentions. A personalized approach of well chosen and targeted actions tends to be the only yet difficult option. We have found, via experience in the metallurgy and chemistry industries, a way of preparing the company and the workforce to accept these sorts of culture changing measures faster and easier. Using company-wide changes based on workplace perception, yields the most optimal acceptance. It is based in the principle that we all use clues in our environment as guides to choose our behaviour. So, controlling the perception that our workplace generates can affect behaviour and simplify our task before it even starts. It is a matter of using the tools that other disciplines such as marketing, social engineering and architecture bring to us and adapting them to a very defined objective: Having our installations “sell” safety so that our people unconsciously believe that they must adapt to safety values in order to “do well” in said environment. INTRODUCTION After decades of improvements in accident rates, we are understandably hitting a diminishing results curve: most actions that spectacularly reduced accidents in the past (e.g., Innovation in Personal Protection equipment, adapting international standards and legislation, and innovative safety programs; Figure 1) now hardly get us the exponential gains we saw years back, regardless of the investment we put on them. Furthermore, the improvements in safety of the last 3 decades have been creating new sets of issues that start to show their face such as: By reducing accidents we can create feelings of invulnerability as we lose view of the consequences. With innovative protection equipment we increase Risk Homeostasis, meaning that people behave in a more dangerous way in order to maintain a constant level of risk in their lives (Getting closer to fire after getting better fire-proof garments for example). Too much Legislation can create a feeling of disengagement from personal responsibility. And despite improvements, we haven’t really solved the production vs safety confrontation, it is now stigmatized and less visible, yet it tends to reappear in moments of weakness.

Jan 1, 2019

By W. R. Hargrave

"Mining OperationsOre will be mined by open pit techniques. Because of the high grade of the deposit and the low strip ratio, mining rates are small relative to most other open pit operations.The ore deposit is located in the valley of the main fork of Red Dog Creek. The bulk of the deposit is located on the southwestern flank of the creek, but mineralization does traverse the creek in both the north and east directions.Erosion has exposed the orebody in a number of locations, and has resulted in oxidation of the mineralization closer to the surface. Although much of this oxide material is very high grade, it leaches readily and, at least in the initial phases of the operation, will be stockpiled and not treated in the concentrator.During construction, 2.3 million mt. (2.5 million st.) of overburden and waste will be stripped from the orebody to expose ore for initial operations. Competent non-mineralized waste will be used to build roads and waste dumps, but the bulk of material removed consists of oxide or ice-rich soils and weathered rock which is not suitable for construction.The annual ore mining rate will be 1.9 million mt. (21. million st.). The strip ratio will start off at 1.2 to 1, falling to 1.0 to 1 by year 5 and ultimately to 0.8 to 1.Bench heights are set at 7.6 m (25 ft). Pit slopes will vary depending on the material present in the wall. The slope, through competent waste and the sulphide package, was set at 45 degrees. This is flattened to 26 degrees (i.e. 2: 1) through overburden and Upper Kivalina shales. The Kivalina Shales are an ice-rich shale whose carbonate matrix has been leached out and which exhibits little or no strength as it thaws. In addition, a 100 ft containment berm will be left in the wall below overburden and Kivalina."

Jan 1, 1989

By Ross L. Sherlock, David J. Scott, Gordon MacKay, Wayne Johnson

"Abstract - The demographics of Nunavut indicate a very young and poorly educated population spread over wide areas in small isolated communities. The current economic sectors will be unable to expand and meet the demands of this emerging workforce. Given the realities of Nunavut, the most promising direction in which the economy may expand is through mineral development. The Nunavut Land Claims Agreement (NLCA) has established the legislative framework for sustainable development in Nunavut through mineral development. The NLCA has transferred ownership for much of Nunavut’s potential mineral resources to beneficiaries of the lands claim. Royalties generated from mining operations on subsurface Inuit-owned lands, and to a lesser extent on Crown land, will flow back to beneficiaries of the lands claim through their administrative company, which may then be invested in the communities. Additional benefits of mineral resource development in Nunavut will be realized through impact and benefit agreements.To realize the benefits from mining operations, Nunavut has to be able to attract and support exploration and development companies through the release of high-quality geoscience data. However, due to Nunavut’s isolation and the expense of conducting geoscience fieldwork, the jurisdiction lags far behind the rest of Canada in terms of quality and quantity of government geoscience. About 70% of the territory is inadequately mapped to attract exploration companies or to make informed land-use decisions. The role of government-funded geoscience in Nunavut is to stimulate exploration and discovery through new framework mapping and focused thematic projects. The timely delivery of high-quality geoscience products will attract exploration companies to Nunavut and further their efforts to discover and develop mineral resources in order that the subsequent benefits of this activity may flow to the beneficiaries of the NLCA as well as all other residents of Nunavut."

Jan 1, 2003

The Autogenous milling of ores holds an increasing attraction as the focus moves towards reducing energy usage, both direct and embodied in grinding media. However, most of the early AG mills were converted to SAG for improved stability and increased throughput. This imposes a huge penalty in steel grinding media consumption. The LKAB iron ore operations in Sweden process highgrade magnetite through fully-autogenous milling lines to a final product P80 of about 45µm. The outcomes of P9O AMIRA research surveys, covering a wide range of mill fillings and throughputs and with different feed blends, are presented. Insights are provided on operational strategies, opportunities, the influence of feed size control and balancing the blend of competent gangue and softer magnetite. Areas of importance in the successful operation and control of energy-efficient autogenous circuits are highlighted.

Jan 1, 2012

By R. D. Brown

The Federal Government's White Paper on Tax Reform received further major criticism in the reports of the Committees of the House of Commons and the Senate, which recently completed a lengthy review including public hearings of the government's proposals. These reports both criticized the emphasis placed by the White Paper on its concept of tax equity rather than on a system which would promote economic growth. However, the Finance Committee of the House of Commons was prepared to accept, with modifications, a number of the White Paper's key reform proposals. The Senate Finance Committee was more critical of the basic thrust of the tax reform program and recommended that a modification of the existing tax system would be more appropriate to Canada's needs. Both Committees re-commended a more favourable treatment of mining income than that originally proposed in the White Paper, and to some extent both Committees suggested proposals that were even more favourable to the industry than those set out in Finance Minister Benson's amended proposals made in August of this year. This article out-lines the principal recommendations and comments in the reports of both the House of Commons Committee and the Senate Finance Committee.

Jan 1, 1971

By R. L. Brown, E. A. Swanson

THE Buchans ore bodies are located in central Newfoundland, three miles north of Red Indian lake. The townsite of Buchans was named after a Royal Navy Captain who, while attempting to make contact with the Beothuck Indians, camped in the area in 1820. Ore was first found at Buchans by a Mic Mac Indian, Matty Mitchell, who discovered one of the three small orebodies in the bed of the Buchans river. The Anglo-Newfoundland Development Company, which holds mineral rights in the area, developed the orebody, but was forced to give up the venture because of difficulties encountered in separating the various sulphides. The American Smelting and Re-fining Company developed a flotation process which was capable of economically separating and concentrating the various sulphides, and, in 1926, they took a long-term lease on the property.

Jan 1, 1962

By H. J. McQueen

Large-scale industrial production of pipe began with longitudinal hot pressure welding of wrought iron by passage of skelp (narrow strip with beveled edges) through a die or bell that curled it about a longitudinal axis until the edges were forced together. Such small to medium tubes could be reduced by rolling or drawing; with threaded connections, they were excellent for distribution of clean water and of illuminating gas for street, home and industrial lighting. Although steel lacks the fluxing slag for pressure welding it has hot strength similar to iron; hot-pressure bell welding was advantageously transferred to steel in long coiled strip with 50% higher cold strength. For pipe without weld-line defects, hot cupping followed by Pilger mill rolling produced tubing that revolutionized bicycle quality and high-pressure service for boilers and chemical processing. Mannesman hot rotary piercing produced long thick walled tube that permitted reduction or expansion by rolling to provide pipe sections up to 60 cm diameter and 12 m long. During 1910 - 1940, oil and gas pipeline technologies, notably welding evolved markedly as they proliferated in the United States, in response to far-flung petroleum fields, expanding industry consumption and the automobile revolution. In the Second World War combat pipelines were laid rapidly, such as: the Canol line through the Yukon to Alaska, and fuel supply lines across the channel and through liberated France. Perfection of welding techniques for both longitudinal and spiral weld large diameter pipe in combination with controlled-rolling of micro-alloyed steels made possible reliable Arctic pipelines. The development of pipe production and utilization in Canada is recounted. The fabrication techniques and metallurgical controls are explained.

Jan 1, 2005