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By Albert L. Toenges

The production of bituminous coal by stripping methods has become an important factor in some areas, especially in the Central and South Central States. In the latter, production at strip mines exceeds that at deep mines. Table 1 shows the tonnage produced at strip mines and the percentage of the total production for 1924 to 1935, inclusive, for the States in which the mines described in this circular are situated.4/ Following are references to earlier Bureau of Mines publications on strip mining of bituminous coal: Cash, F. E., and von Bernewitz, M. W., Methods, Costs, and. Safety in, Stripping and Mining Coal, Copper Ore, Iron Ore, Bauxite, and Pebble Phosphate: Bull. 298, Bureau of Mines, 1929, 275 pp. Kiessling, O. E., Tryon, F. G., and Mann, L., The Economics of Strip-Coal Mining: Econ. Paper 11, Bureau of Mines, 1931, 32 pp. Turner, Scott, and Bureau of Mines Staff; Mining Bituminous Coal by Stripping Methods: Inf. Circ. 6383, Bureau of Mines, 1930, 23, pp.

Jan 1, 1937

By M Wortley, J Korteniemi, D La Rosa, L Rajavuori

Geometallurgical modelling of an orebody provides benefits to a mine by gaining a better understanding of the ore characteristics and how they affect the performance of the concentrator. With this knowledge, plant operating conditions can be adjusted to optimise throughput and recovery in advance of the arrival of particular ore types. Therefore, it is extremely important that the origin of the ore being processed is known as accurately as possible. Depending on the homogeneity of the ore characteristics, reliance on assumptions about stockpile residence times, scheduling and material handling can render the best geometallurgical models useless.The solution adopted at Agnico Eagle’s Kittilä mine was to utilise Metso SmartTags™ and in-house expertise to develop a system that continuously and accurately links geotechnical and lab data from the mine to the performance of the plant. This application presented several unique opportunities and challenges. For example, this was the first installation of a SmartTag™ system for geometallurgical modelling in an underground mine. Challenges included the fact that the system installation is routinely subjected to temperatures below -20°C.The system was installed and commissioned in early 2013 and has been operating continuously since. Kittilä has begun to see the benefits of the system, with an increased understanding of how different ores are processed in the concentrator. Other advantages include the ability to alert operators about the arrival of difficult ores and a better understanding of the ore handling systems.This paper describes the installation and use of the system at Kittilä and details some of the geometallurgical relationships that have been developed using the data collected so far.CITATION:La Rosa, D, Rajavuori, L, Korteniemi, J and Wortley, M, 2014. Geometallurgical modelling and ore tracking at Kittilä Mine, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By R. V. Mrazek

The heat of formation of vanadium trichloride was determined at 298.15° K. Measurements were made in a solution calorimeter in which an aqueous hydrochloric acid-potassium dichromate solvent was employed. Data are presented for the heats of solution of vanadium trichloride and the vanadium trioxide "backup" compound, and for appropriate dilution reactions needed to preserve stoichiometry. The resulting heat of formation of vanadium trichioride (VCI3) at 298.15° K was found to be ?H°298.15° K = -138.89 ±0.37 kcal/g mole.

Jan 1, 1968

By Beatryz Mendes, Leonardo Pedroti, Afonso Azevedo, José Maria Carvalho

The dregs is a waste from the cellulose production, and its reuse is an effective way to reduce environmental impacts. Researches have already been done to incorporate it into building materials. The present work aimed at incorporating dregs in the production of mortar to replace hydrated lime. The methodology adopted was the Simplex network with ten sampling points, varying the amount of cement, sand, and dregs. Each mix was submitted to flexural strength, compressive strength, apparent mass density and water absorption by capillarity tests. The results were analyzed by the software Minitab, obtaining the influence of each component in the mixture. The best results were observed in mixes with a higher proportion of cement and less of residue when it was analyzed the flexural and compressive strengths. Larger rates of apparent mass density and water absorption were noticed with a greater amount of dregs. The experimental design also allowed the obtainment of mixture ratios from predetermined values of the tested properties and indicated that the addition of dregs in mortar could be an alternative to civil construction.

Mar 1, 2018

By Wenxian Zhu, Patrick R. Taylor

"The small dimensions of nano-sized materials leads to novel and enhanced mechanical and physical properties. A thermal plasma reactor has been developed to study the formation of nanometer sized metal powders. A supersonic nozzle and a powder filter were designed and built. By vaporizing coarse metal powders in the plasma flame, and quenching the metal vapors through the nozzle at the rate of 107 K/sec, nanometric sized powders have been produced. The powders were collected in an airtight secondary quench-filter system. The particle size of the product power is 5 -20 nanometers, obtained through TEM analysis. The XRD analysis showed that the powder did not oxidize after the filter was handled in an inert atmosphere glove box.IntroductionNanostructured materials have been shown to exhibit improved physical and mechanical properties compared to conventional materials with larger grain sizes (1,2). There have been several methods proposed for preparing nanometer size materials. Thermally induced vapor-phase reactions have been used to produce a variety of powders. A common feature of these processes is the rapid production and cooling of condensable reaction intermediates and products, by gas-phase reactions, leading to the formation of a large number of very small particles. Thermal plasma synthesis of ultra-fine size particles has been attracting increasing interest (3,4,9-11), because it offers many advantages, especially in refractory materials processing, compared to conventional processes: (a) thermal plasma temperatures are very high(> 5000 K); (b) the rates of chemical reaction are much faster than those encountered in conventional processes; (c) high-purity materials may be obtained using fewer processing steps by collecting the product at temperatures where the by-products are in the vapor phase; ( d) the mean particle diameter can be controlled; (e) unifom sized particles may be produced with clean surfaces (these particles are particularly suitable for pressureless sintering); and, (f) high throughput per reactor volume can be achieved. In addition, the process used for generating particles determines the degree of sintering ability of the powders, since the process dictates the morphologies, the purity and its size distribution. In the future, thermal plasma synthesis nanometer size particles may play an important role in vapor phase reaction techniques and might be expected to be one of the first full scale commercial installations in the future."

Jan 1, 1998

By J. F. Dorion

This paper presents the results of on-going investigations on the performance of support systems in Québec underground mines. The focus of these investigations is on site observations complemented by laboratory investigations. Of particular interest is deducing the corrosion rate, at selected mine sites, as determined by the installation of monitoring coupons.

May 1, 2009

By D. M. Wyslouzil

Standard testing methods are described that are presently used for the selection of grinding equipment. Correlation between laboratory batch grinding tests and pilot plant continuous tests are established by means of particle size distributions and flotation results. Conventional and autogenous grinding circuits are discussed showing the relationships of the controllable circuit parameters.

Jan 1, 1982

By Scott Turner

Since my whole life has been spent in the mining business , I naturally tend to address my remarks particularly to the newly- graduated mining and metallurgical engineers among you . To a certain extent , all forms of engineering principles are involved in the training of the mining engineer , and most sorts of engineering are certainly utilized by him , so that every one of this graduating class is concerned with the field I propose to discuss . The fact that , beginning with to - day , you will always be styled engineers , indicates that you have passed successfully through preparatory school , and have survived the hard grind of the technical college . One object of your training here has been to instruct you in accurate , close , and clear thinking . Your minds have been taught to act directly , calmly . and always to the point . By now , you should know how to get facts , look far , and think through . You are supposed to be willing to recognize and adopt sound engineering principles and practices , in so far as they are known to you , and to furnish character , ability , and devotion to your calling . Some of you may have had a general college course before coming here to specialize in engineering . Where that has been possible , I hope it is the case , since a liberal educational course tends to make the alumnus more flexible and adaptable than the purely scientific graduate. The broader education enables one to change , with less serious loss , from one job to another; ready adaptability is a great asset ; the engineer should be capable of much more than a single special task . The necessary preliminary training for a professional occupation is intellectual in character , involving knowledge , and to some extent learning , as distinguished from mere skill . The well -balanced engineer is expected to embody a happy combination of theory and fact , of pure science and material reality ; experience shows that he is apt to give a good account of himself , once he gets the chance . For the long pull , the importance of unquestioned integrity can not be overemphasized . Leaders of big business sometimes have need for a man as agile and unscrupulous as a cat on a back fence ; on occasion , they may have to employ brilliant , smart , spectacular , and crafty people , but when the special purposes for which such men are hired have been accomplished , they are no longer wanted . Given natural health , intelligence , ability , and adequate training , probably the characteristics most admired in the young employee are steadiness , dependability , and loyalty . The last is the best . If you can not be simple , direct , and faithful in your dealings with your administrative superiors , no one will want you for long . I believe these points are of primary importance to the young engineer . Your groundwork must be right before you can get far . These personal characteristics are what eventually determine your relations with men and affairs . They are vital in the human engineering which may be a large part of your work .

Aug 1, 1932

By M. W. Von Bernewitz

The Bureau of Mines receives frequent requests for information on the treatment of mercury ores, but as its own and almost all other publications on mercury are out of print, the Bureau has prepared this circular on the metal for the prospector and operator of small mines and plants. Mercury, commonly though improperly termed ?quicksilver?, is the only common metal that is liquid at ordinary temperatures. Mercury is used in the amalgamation of gold and silver, in power boilers, explosives, friction-less bearings, laboratory apparatus, lamps, medicine, paint, rectifiers, and for ?silvering.? The last mentioned is being superseded by silvering with silver. The use of mercury boilers may increase when they are thoroughly understood, but amalgamation is -being replaced to some extent by the use of corduroy and other collecting mediums, such as jigs and flotation cells.

Jan 1, 1937

By J. Douglas Causey

No mines are active in the Hunter Mountain Wilderness Study Area (WSA), and no mineral resources have been identified in the WSA. However, the Monarch Mine has low potential for silver, copper, tungsten, and gold resources in quartz veins; the Shirley Ann Group and Sal Group have moderate and low potential, respectively, for silver, lead, and copper resources in skarn; claims overlying the Eureka Quartzite have low potential for silica resources; and the Tourmaline N1-4 Prospect has low potential for tourmaline resources in quartz monzonite. Copper, lead, silver, tungsten, molybdenum, wollastonite and garnet occur in skarn zones between monzonitic and carbonate units. Silver, tungsten, and copper also occur in quartz veins within monzonite. Known metallic mineral deposits are small, erratic and discontinuous. The J. 0. Mine, adjacent to the northeast corner of the WSA, may contain as much as 26 million tons of subeconomic wollastonite resources. The crest of an open pit to produce that resource would extend into the WSA. No information exists on geothermal potential because no exploration has been done in the area. No occurrences of energy minerals are known within the WSA.

Jan 1, 1983

By Z. Botha

Sheryl Sandberg, the COO of Facebook, published a book titled 'Lean In', where she invites women to sit at the table. In summary, to 'sit at the table' entails not only embracing opportunity, but to actively seek out opportunities in leadership positions. Sandberg points out that, unfortunately, apart from institutional obstacles, a woman's own perceived limitations have a negative impact on her leadership ambitions. To create an environment where diversity will flourish, where everyone has a seat at the table and everyone has a voice, safety must be established first. To establish safety within a diverse team, there is power in relationships and connections. This study will first and foremost review theories in literature as to why diversity and inclusion are so important and the value that diversity brings to our industry. The study also recommends a few focus areas for improving diversity and inclusion in the industry.

Sep 1, 2022

By N Berkowitz

Slurry pipelining, as now under-stood and practised, can only command marginal interest in Canada, as long-distance railway freight charges in this country are generally lower than slurry pipeline tariffs. Several alternatives to conventional slurry transmission are, however, now emerging, and two such alternatives are briefly discussed with reference to coal pipelining. In one, coal is transported as a suspension in oil; the other contemplates the movement of paste "slugs." Preliminary economic estimates indicate that the resulant process simplification and adoption of common carrier principles could lead to cost reductions that might make Western coal competitive with imported fuel in the power generating stations of eastern Canada. R ECENT appraisals of slurry pipelining techniques, some-what incongruously 'based upon the performance of successful installations (1,2), are making it increasingly apparent that current solids pipelining methods can only command marginal interest as methods of bulk commodity transportation (3). Although some uncertainties remain in matters of detail, it is now generally conceded that long-distance slurry pipelining cannot compete against rationalized railway transportation unless movement of

Jan 1, 1963

By J. O. Down

St. Marys Cement Company operates two cement plants in Southern Ontario, Canada. The original plant, located at St. Marys, a town 20 miles north of London, Ontario, began operations in 1912. A second plant, located at Bowmanville, Ontario, 40 miles north east of Toronto, began operations in 1967. In June 1973, St. Marys Cement began feasibility studies of modernizing their wet process plant at St. Marys. Over its 61 year life, this plant had been expanded from 335 m. tons per day (375 s. tons per day) to 2000 tpd (2200 s. tons per day), with all the original equipment retired several years ago. The objectives of the feasibility study were to develop a conceptual plan for a dry process plant and to de-, fine the appropriate process method and equipment. This study proceded along four fundamental fronts: a) How could the clay raw material, a glacial till with up to 20% boulder content, be processed in dry form and beneficiated? b) Were the raw materials suitable for the most efficient form of dry process kiln, the 4-stage preheater? If a 4-stage preheater kiln is selected should it utilize a precalciner? c) What type of clinker cooler should be used? d) What environmental constraints would be imposed on this plant and how can they be reconciled with capital and operating limitations? During the feasibility stage, pilot plant work was done on two possible solutions to the clay problem, operating plants in Europe were visited and discussions held with kiln and mill vendors.

Jan 1, 1977

By J-P Franzidis

Mill operators have traditionally been forced to rely on grade-recovery curves and overall flotation rate constants when analysing proposed improvements to plants. This has led to loss in money and time when a proposed change that showed potential in laboratory scale tests failed to show improvement in the plant. Frequently, this is a result of the operators being unable to gain insight into how and why the proposed change affected the flotation performance. This is due to the classical models not including any description of the subprocesses of flotation and their individual contribution to the overall flotation performance. A new flotation model has been developed as part of the AMIRA P9 project that separates the flotation process into subprocesses and includes the contribution of both the pulp phase and froth phase to the overall flotation recovery. It is not possible to determine the individual components of this new model on traditional pilot plants as they lack the required flexibility and scale. Therefore a new pilot plant has been developed known as the Floatability Characterisation Test Rig (FCTR) that has the flexibility and features required for the determination of the flotation subprocesses. The flexibility and features of the FCTR also make it an ideal tool for investigations into many different aspects of flotation research. These include the effect of reagents, grinding, and power on the flotation performance. This paper will describe the methodology for using the FCTR in these fields of research and highlights the advantages of using the FCTR over traditional methods.

Jan 1, 2000

In October 1993 it was decided to undertake the fourth phase of mining at Big Bell. This decision followed the exhaustion of open pit reserves in January 1993. Two stages of mining were proposed for the new underground mine. The initial stage would mine the remnant ore, consisting of the rib and crown pillars and lower grade ore on the hangingwall and footwall side of the old open stopes, which were mined from the 1930s to 1950s. Most of the old open stopes were backfilled with either deslimed mill tailings or development mullock, both of which were economic to recover. However, the mineable ore from this resource was difficult to evaluate. The second stage focused on mining ore outside the remnant areas and was initially proposed as a Core and Shell method under a caving hangingwall. This method has since been superseded with sublevel caving, in part due to the very high and deviatoric stress conditions encountered at Big Bell and the relatively long mining cycle required for open stoping. The problems and challenges discussed in this paper will cover the identification of remnant ore reserves, dewatering the old workings, and remnant mining.

Jan 1, 1998

By I. A. Ettlinger

DEPRECIATION allowances have become firmly rooted in our income tax structure both by legislation and by court decisions. Secretary of the Treasury Morgenthau has recently stated before the Ways and Means Committee of the House: A taxpayer who did not provide for depreciation of assets used in his business could not long remain in business and the income tax should be levied on the assumption that he will provide for such depreciation. The 1934 Revenue Act has now been enacted, the depreciation provisions of the 1932 Revenue Act having been carried forward without change. However, there has arisen, in connection with the preparation of this new Revenue Act, a determination by the Treasury Department to make certain changes in the future administration of the depreciation allowances that will affect all corporations, and mining companies in particular.

Jan 1, 1934

By Robert D. Hansen, Basil S. Fee, Richard R. Klimpel

Despite the importance of froth flotation to the mineral industries as a means of separating various minerals, the commercial flotation reagents used have varied little in the last twenty years. Numerous articles and books are available describing existing flotation chemistry and its application, e.g., Fuerstenau (1962), Fuerstenau (1976), Aplan (1980), Somasundaran (1980), King (1982), Leja (1982), Ackerman, et. al. (1984), Crozier (1984), Hansen and Klimpel (1985). There are many reasons for this lack of significant new reagent development including the general utility and relative cheapness of collectors, such as xanthates, and frothers, such as methyl isobutyl carbinol and the glycol ethers. Another important reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials which make reliable reagent comparisons difficult and seriously limit the use of theoretically based studies to "predict" new or optimal reagents. In addition, the higher cost of "specialty flotation reagents demands that their performance attributes be significantly greater than existing general all- purpose commercial reagents – something often difficult to prove in practice. Faced with this situation, a detailed applications research pro- gram [Klimpel (1980 ab, 1982, 1984 ab), Klimpel, et. al. (1982)] was organized from 1979-1985 on mineral flotation with the following goals: 1) the development of appropriate batch laboratory flotation testing techniques sensitive enough and statistically reliable enough to identify small differences in performance between different flotation tests (i.e., between various reagents, even those with relatively minor chemical structural changes); 2) the identification of mathematical models with appropriate numbers and types of parameters that have maximum statistical power to statistically distinguish between various time-recovery profiles; 3) the generation of laboratory and corresponding plant scale data in sufficient quantity and consistency so that the highly interactive nature of the "flotation system9' of chemistry/ equipment/operating conditions could be quantified; and 4) the invention and development of really new and unique reagents for giving improved flotation performance. The goal #1 was achieved [Klimpel (1980b. 1984b), Meyer and Klimpel (1984)l by basically using a simple automated paddle device for consistent

Jan 1, 1986

By E. P. Youngman

Tantalum is a rare element ; estimates indicate that there is less tantalum than gold in the earth's crust . After remaining a laboratory curiosity for many years , it was used to a limited extent and for relatively few years (1903- 1911) for incandescent electric-light -bulb filaments . Another wave of interest in tantalum appeared when its electrolytic-valve action was taken advantage of in charging storage batteries , especially for radio work . Tantalum chargers were eventually displaced by other types of chargers , but for a time they were manufac tured in sufficiently large numbers to create a demand for the metal and to bring about its production on a commercial scale in the United States . As tantalum became available in larger quantities and at substantially lower prices , and as high prices for platinum encouraged the employment of tantalum as a substitute , the metal was put to many new uses . Ferrotantalum was made and sold before the World War , and patents have been taken out for a number of special alloys for industrial purposes , but probably the largest use for the metal to-day is in vacuum tubes .

Aug 1, 1930

By Karin Bäppler

Mechanized tunnelling is undoubtedly one of the most innovative disciplines in the international construction industry. Technological progress in the planning and production of most modern infrastructure is constantly striving for new records on basis of highly specialized solutions and know-how. Humans and technology have accomplished excellent achievements over the past few years in varied, difficult terrain. New length records are being set with the 64 km long Brenner Base Tunnel and the HS2 Railway system currently under construction in Europe. Cities are building ever longer and more demanding sewer tunnels. The paper highlights some of the challenges, trends and innovations of long-distance tunnelling projects.

Dec 1, 2022

By R. E. Cumings

The Bureau of Mines made electrorefining tests in inert-atmosphere, molten salt cells to develop methods for the preparation of high-purity molybdenum. Seven of the electrolytes investigated were suitable for the preparation of refined metal. The electrolytes were composed of molybdenum chloride in alkali chlorides or mixtures of alkali and alkaline-earth chlorides. An electrolyte composed of potassium chloride and potassium hexachloro-molybdate was selected for a larger scale, more detailed study on the basis of its ease of preparation, its ability to retain the molybdenum salt, and the type of deposits obtained. High-purity molybdenum in the 99.99-percent-purity range was successfully prepared as dense plate up to 80 mils thick and as dendritic crystals. The temperature of electrolysis and the current density were major factors in determining whether plate or dendritic crystals of molybdenum were obtained.

Jan 1, 1966