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By Phil Keele

Canadian Natural ??Business Approach Efficiency and Execution ?Drive to be the low cost producer ?Focus on exploitation ?Augment exploitation with strategic acquisitions ?Maintain Discipline and Strength while Delivering on the Defined Plan ?Maintain flexibility and control allocation of capital ?Strive for balance (asset portfolio) ?Maintain financial strength

May 1, 2010

By Lawrence S. Darken

STAFF: Editor, Gerhord Derge Cornegie Institute of Technology Schenley Pork Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: J. S. Smart, Jr., President; C. C. Long, Past-President; K. L. Fetters, Vice President; T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: C. L. McCabe, Chairman; H. L. Bishop, K. L. Fetters, J. J. Harwood, W. A. Krivsky, F. C. Longenberg, R. E. Lund, W. 0. Philbrook, L. L. Seigle, R. L. Smith, and F. L. Vogal. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: C. L. McCabe, Chairman; R. E. Lund, Vice-chairman; D. H. Baker, Jr., W. A. Krivsky, R. A. Lewis, Paul Qusneau, A. S. Russell, R, E. Shinkoskey, W. W. Stephens, and M. E. Wadsworth. Institute of Metals Division: L. L.Seigle, Chair-man, P. A. Back, J. J. Backer, l.l. Bessen, J. 0. Betterton, Jr., J. 8. Clark, R. S. Davis, A. E. Dwight, R. W. Fountain, R. B. Gordon, C. D. Graham, Jr., R. W. Guard, J. C. Gurland, E. L. Harmon, J. J. Hager, A. A. Hendrickson, M. Harmon, J. N. Hobstatter, H. H. Johnson, Jr., H. 5. Kolish, R. R. Nash, T. N. Rhodin, R. H. Richman, W. Rostokar, P. G. Shawmon, C. W. Spencer, L. Slifkin, J. K. Stanley, C. D. Starr, R. Steinitz, and H. C. Stumpf. Iron and Steel Division: H. L. Bishop, Chairman; 2. E. Boni, F. C. Langenberg, J. B. Wagstaff, and T. V. Wainwright. Published bimonthly by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription PetroleumEngineers,$30 per year for non-AIME members in United States and North, South, and Central America; 332, foreign; $5 for AlME members. Single copies, $4.00, single copies foreign, $5.00. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1%1 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address; AIME New York ..Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts.. .Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 221, Number 4.

Jan 1, 1962

By H. Krogerus, P. Niemelä, P. Oikarinen

High carbon ferrochromium is produced by carbon reduction. No replacement for carbon as reductant has yet been developed. The reduction creates a considerable amount of CO-gas. In open and semi-closed furnaces the gas is burned when leaving the burden. In closed furnaces the formed gas is sucked out by a fan, washed and utilised as fuel. The formation of carbon monoxide is presented briefly starting from thermodynamic considerations up to solid and liquid state reduction. The volume, composition and energy content of the furnace gas are discussed, focusing on the raw materials and pre-treatment processes of the furnace feed as well as on the process equipment and control. Outokumpu has been using closed and sealed furnaces and utilising the CO-gas in its Tornio Ferrochrome Works since 1968. Today in Tornio with an annual ferrochromium production of 260 000 t CO-gas production is 186 million m3, representing 68 MWh an hour. At the same time the furnace power input is 95MW. About 98 % of the CO-gas is utilised, whereof 30% in the ferrochrome production itself. This paper focuses on the characteristics and utilisation of CO-gas. CO-gas is secondary energy, which on one hand saves primary electric and fossil fuel energy in ferrochromium production and, on the other, replaces other fossil fuels at the adjacent steel works. The characteristics of the fuel, requirements for utilisation as well as health and safety aspects are discussed. Utilisation of the gas has a high impact on the total dust and gaseous emissions and on the energy optimisation at the ferrochromium and steel works.

Jan 1, 2004

By R Williams, M Baxter, D Zink, R Cunningham

The purpose of this paper is to discuss the efficient operation of a tailings dewatering circuit comprising a thickener and filter press through proper control and automation. It is common to see thickeners and filter press circuits each with their own control systems. This can cause multiple issues when trying to increase efficiency and reliability of the tailings management process. By automating the thickener and filter press controls, you are eliminating any delays and inconsistencies caused by human error and process variations. When done properly the system can maintain a consistent product as the feed characteristics change. Previously, operators would have to monitor the process parameters and adjust the system accordingly. This can now be accomplished using state of the art process control equipment that continuously monitors and adjusts critical variables using Programmable Logic Controllers (PLC) and Proportional Integral Derivative (PID) loops. The paper will detail the control theory used to maintain these systems, highlight other benefits of having a fully integrated plant such as predictive maintenance and remote diagnostics as well as present examples of how these have been implemented in field examples.CITATION:Baxter, M, Cunningham, R, Williams, R and Zink, D, 2018. Tailings process optimisation through automation and controls integration, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 416–421 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By Paul Wellman

The energy problem of the U. S; was emphasized by the oil embargo of late 1973 and early 1974 and it seemed for a time that the Federal Government, under pressure from the general public, might take some corrective action. However, this was not the case. With the gasoline lines gone and an apparent plentiful supply of petroleum products, public concern quickly dissipated., This country is more vulnerable to an oil embargo today than we were in 1973-1974 and this fact should be of concern to all our people. Since 1968, we have used oil and natural gas at a much more rapid rate than we have been able to find new domestic sources; thus, there is an increasing gap between domestic production and consumption and we have filled the gap with ever increasing oil' imports. These imports have increased at an alarming rate in the recent past, some 58 percent in 1976 compared with 1975. Imports are nearing 8 million barrels per day. Then, by applying some simple arithmetic, at $12 per barrel, the resulting trade deficit is $96 million per day or $35 billion per year. Obviously, this cannot be tolerated by our economy over a long period of time. Historically, we have shifted from one fuel to another as is shown in this slide. In 1850 about 90 percent of our fuel requirements came from direct combustion of wood, by 1900 we shifted to coal for 70 percent of our fuel, and now about 78 percent of fuel requirements comes from oil and natural gas. The difference is that the previous shifts were voluntary and the one facing us now is of necessity.

Jan 1, 1977

By H. J. Ilgner

The paper reviews the results to date of an integrated research programme currently being conducted by CSIR Mining Technology, aimed at impacting significantly on concentrated mining with face advance rates of up to 20 times faster than presently achieved. Consideration is given to the interplay between innovative technologies for continuous non-explosive mining or rock comminution underground and lateral hydraulic transportation in cross cuts, haulages and eventually hydro hoisting. Novel technologies for underground comminution of reef and development waste and an innovative pumping system suitable for the hydraulic transportation of coarse comminuted rock are reviewed. Emphasis is placed on South African gold mine reef and waste samples comminuted by electric shock wave comminution technology. The innovative TORE® pump system appears to be well suited for the successful hydraulic transportation of rock, produced by electric shock wave comminution, at solids concentrations between 45 % and 67 % by mass.

Jan 1, 1997

By Robb L. Swenson

Construction of foundations for the Skyway Segment of the San Francisco Oakland Bay Bridge required innovative techniques due to the mass of the structures being inserted and the unique subsurface of the Bay. Twenty of the pier structures required large sheet pile cofferdams. Eight other foundations were installed in open water without cofferdams at the deeper part of the Bay. This narrative will present the initial planning, as well as the stages of installation, for each type of foundation. The first section will discuss foundation constructability modifications made during the initial planning phases of the project. Considerable effort was expended by Caltrans, the owner, T.Y. Lin the designer, and KFM (Kiewit/FCI/Manson) the contractor in modifying the design to assure that required tolerance would be maintained during the installation of the foundations. The final section will describe the steps required for installation including: initial access dredging, installation of cofferdams, preparation required to install the footing boxes, footing box installation, foundation support pile installation, and pile to box connections.

Jan 1, 2005

By Adrian Moore, Alan Richards, Andrew Brodbeck

Structural blast vibration limits should be based on the strength of the structure, the stress induced by blasting, and a responsible factor of safety. In this paper a methodology that uses direct strain measurements to determine the stress induced by blasting is described. The methodology has been used to measure strain resulting from blasting, and establish appropriate blast vibration limits on a brick sewer tunnel, an underground mine heading, brick veneer houses, a water pipeline, and transmission tower foundations. An outline is given of the use of the methodology to establish limits for the main entry heading of an underground coal mine, and transmission tower footings. The methodology that is described has reduced uncertainty factors, and permitted the specification of higher blast vibration limits than had been previously used.

In a previous paper the writer dealt -with the jasper bar formations and their relationship to the structural geology of older pre-Cambrian rocks in the goldfields districts of Western Australia (24). He has pointed out in this ahd other papers that jasper bars, or banded iron formations, banded hematite or ,magnetite quartzites, jaspilites and related banded ferruginous or non-ferruginous cherts, occur in abundan'ce in the Older Greenstone Series of Western Australia (22), (24), (26). They are considered to represent special forms of banded ferruginous sediments, and are usually fpund in the field interbedded with more or less metamorphosed pasaltic 01' andesitic lavas and tuffs, now amphibolites, together with occasional thin bands of normal pelitic sediments, which go to make up a large proportion of the Older Greenstones in thfs State (26).Great thicknesses of fiat-bedded ]:landed ferruginous cherts are also found associated with cherty' carbonate rocks; quartzites, shales and thin-bedded dolomite whicIi constit'ute the Nullagine (Pl'oterozoic) system in the northwest of Western Australia. In the Hamersley Range district these banded ferruginous chert beds are the hosts of important deposits of blue amphibole asbestos.In the paper mentioned above brief reference was> made to the importance, of geological structure in relation to economic geology, particularly in the goldfields regions of Western Australia, and it was shown that jasper bars may have an important role in the study of 'the structural geology of many of these regions. Of possibly more immediate economic importance is the part that these rocks play, both directly and indirectly, as host rocks for mineral deposits-the chief of Which are gold, iron ores, blue asbestos, and manganese ores. The blue asbestos bearing banded iron formations mentioned above are confined to the younger pre-Cambrian Nullagine formations. They have been described in detail elsewhere (23). In this paper it is proposed to discuss the economic geology of the jasper bars found in the older pre-Cambrian series.The jasper 'bars have in themselves little or no intrinsic value except perhaps some of the more highly coloured and banded varieties which may be utilised for ornamental and decorative purposes. Probably the best known of such varieties is the so-called "marble bar;" a belt of, strikingly coloured banded chert occurring just south and west of the famous town of that name (see Fig. 1t). This consists of a hard, very fine, even-grained rock with alternate individual stripes varying from the thickness of a sheet of paper up to an inch or more in width, and ranging in colour from clear white to yellow, from various shades of pink to brilliant...

Jan 1, 1943

Investigation of the Classification Operation in a Coal Pulverising Vertical Spindle Mill Coal pulverisation in power plants is a major electrical energy consumer. In 2006 more than 41 per cent of world electricity generation was from coal where pulverisers use 0.5 to 1 per cent of gross generation. Therefore, pulverisers are an important target for optimisation not only for reducing costs of power generation but also for reduction of greenhouse gas emissions. A better understanding of the operation of pulverisers is an essential requirement for their optimisation. However, little information is available, other than operating experience, on the performance of pulverisers and how these react to changes in operational variables. This study investigates the effect of changes in coal and airflow feed rates on the classification performance that occurs in an industrial scale ball-and-race vertical spindle mill in which the pulverisation and classification processes are linked together due to the separator classifier being an integral component within the pulveriser. In order to decouple the breakage and classification processes, samples were cut from upward flowing streams through sampling ports drilled on the pulveriser body at different locations. Specific sampling tools were developed. Samples collected from the pulveriser were size and density fractioned to distinguish the differences in behaviour of the components, namely coal and mineral matter. The coal flow rates on dry basis within the mill and around the separator classifier were calculated by mass balancing the multi-component data. The difference in classification behaviour of components during pneumatic transport was confirmed. The response of the circulating load in the mill (~600 to ~1100 per cent) as well as the dependency of fineness of the streams to the operating variables was demonstrated. The approach taken in this study has proved that development of a classification model for a vertical spindle mill pulverising non-homogeneous materials, eg coal, requires treating these materials as multi-component/composite substances.

Sep 13, 2010

By Shirley F. Colby

The past 40 years have seen the sand and gravel industry grow from small roadside pits and holes in farmers' back yards to giant corporations selling millions of tons of sand and gravel each year and owning plants representing huge capital investments in land and equipment. The days hen a man could "work out" his taxes by providing the materials for nearby roads are gone forever. In addition to the hundreds of privately owned and operated plants, Government agencies operate sand and gravel pits and plants to supply aggregates for the tremendous road-building and public-works programs in progress during the past few years. EXPANDING PRODUCTION In 1940 the send and gravel industry produced almost a quarter of a billion short tons valued at more than 110 million dollars. This compares with less than 2 million short tons worth 1 1/2 million dollars produced in 1902. The practice of screening sand and throwing away the gravel in the early days of the industry's growth has stopped, and in 1940 gravel constituted two-thirds of the total production. In 1906, the first year in which sand and gravel were reported separately gravel accounted for only one-

Jan 1, 1942

By Leon Lorenzen, Charlene Gokhale

"In excess of 24 x 106 tons (Eskom, 1997) of coal-derived fly ash is produced annually in South Africa for the production of electric power. A large quantity of this ash is disposed of as a solid waste in landfills, thus posing a serious environmental problem. Due to the shortage of landfill sites, new ways of utilising fly ash are needed. Recently several authors have shown that various combustion fly ashes can be converted into zeolites to obtain industrial products with applicability in environmental management. Geopolymerisation has emerged during the last few years as a possible solution to some waste stabilisation and solidification problems. henolic compounds have been shown to be toxic to soil microorganisms at the parts-per-million level. Indeed several of the organic compounds classified by the U.S. Environmental Protection Agency as priority pollutants, are phenols. Immobilisation of phenols by adsorption on zeolites and encapsulation in a geopolymer appears to be a promising solution to this problem.This paper reports a technique for the production of a low-silica sodium zeolitic material from fly ash (zeolite NaP1), and its application for the stabilisation of phenols by adsorption and subsequent encapsulation in a geopolymer matrix. A commercial zeolite, clinoptilolite was also utilised as an adsorbent. Due to their uniform pore sizes and large surface areas, zeolitic materials are suitable for ion exchange and adsorption of certain organic substances. Adsorption data show that the commercial zeolite, clinoptilolite was an effective adsorbent for organics. Adsorption data showed that between 51.2 ppm and 74.3 ppm of chlorophenol or between 15.4 ppm and 32.5 ppm of phenol could be adsorbed. Physical encapsulation of the coated zeolite loaded with organic within a geopolymeric matrix increased the compressive strength of the matrix from 28.80 kN to 40.79 kN. Leaching data for the various geopolymer matrices with encapsulated and loaded zeolites show no organics being leached from the system at a detection level of 2ppm. According to the SABS these would have been acceptable organic concentrations within a waste water stream."

Jan 1, 2003

By NEWTON B. KNOX

IN Bolivia, mining is still the principal economic activity, as it was before and during the Spanish Colonial period. Tin, tungsten, antimony, copper, lead, zinc, gold, silver, sulphur, and a little bismuth are produced. The Andes mountains are divided into two main ranges in Bolivia; the Western range marks the border with Chile and the Eastern range forms the backbone of the country; in the North it drops rather abruptly eastward, to the plains of the Beni, whereas in the South it splits and is separated from the Chaco flatlands by a series of folded mountain ranges. In general the mineral deposits are found within the Eastern range or in the hills that rise from the high plateau between the ranges - really parts of the Eastern range partly submerged by recent sediments. The mineral belt is thus over 500 miles long and about 100 miles wide and includes most of the principal centers of population and the most important means of communication. The region is mountainous and the roads are bad; furthermore labor is a serious problem, for the land is poor and the agricultural population is never far from hunger. The floating supply of miners is limited and soon exhausted in any emergency like the present.

Jan 1, 1945

By Peter Townsend, Sergei Diachenko, Allan Moss

The Palabora Mining Company has successfully extended the life of its operation by developing a 30,000tpd block cave underground mine below the now closed open pit. The process of transitioning from surface to underground mining has been technically, operationally and managerially challenging. This has been due to a number of factors; in particular, the development of a block cave in a very competent rock mass. The competence of the rock mass is clearly demonstrated in the open pit that preceded the block cave, one of the steepest deep open pit excavations in the world. With cave breakthrough, however, the pit was ?instantaneously? deepened by 400m causing a major failure of the northwest wall involving close to 100Mt of waste material.

Jan 1, 2006

By E. Z. Manos

The Detroit salt mine is operated by the Detroit Salt Co. It is one of the oldest underground room-and-pillar mines in the United States still in production. Mining at the Detroit salt mine began in 1906 with the sinking of the No. 1 shaft. Mining continued through the years, becoming progressively more modern in its equipment and techniques, until it was closed in 1983. In 1997, after a period of care and maintenance, the newly formed Detroit Salt Co. decided to reopen the mine. Upon completion of an extensive rehabilitation program, salt production resumed in 1998. Production currently continues at a rate of 910kt/a (1 million stpy). To date, the Detroit salt mine has mined more than 45 Mt (50 million st).This mine is unique because it lies under a heavily urbanized area within metropolitan Detroit. The mine and its history make a good case study for the continuing coexistence between the mining industry and its environs.

Jan 1, 2003

By M. Gaula

"Gold bearing deposits of the Witwatersrand basin are generally less than 2m thick and require conventional narrow-reef mining methods for extraction and employ explosives as a means of rock breaking. Optimal utilization of explosives is dependent on the overall design of the blast. The under-utilization of explosives arises when shot-holes are drilled inconsistently, overcharged, and when tamping is absent. This can be rectified by emphasizing the importance of good drilling practices as part of induction programmes and refresher courses. The project was aimed at determining whether or not explosives are being optimally utilized at project site. This was investigated through a study of the properties of explosives, mine standards, and recommendations for usage. Underground observations were made to determine whether or not mine standards were being adhered to. Historic data was obtained to establish the historic relationship existing between the quantity of explosives used (kg) and the production output (m2). This was then compared to the quantity of explosives the mine expects to use per unit of production. The results obtained were analysed to determine the presence and extent of over- or under-utilization. It was found that explosives are being under-utilized at the mine. More explosives are ordered than expected per unit of production. The explosives’ properties are not thoroughly exploited during blasting, thereby requiring the use of more explosives than prescribed. Paper written on project work carried out in partial fulfilment of BSc. (Mining Engineering)"

Jan 1, 2015

By R. D. Stewart

Paper presented at the conference: Risk assessment in the extractive industries, held in Exeter, UK, 23-24 March 1994, and first published London: IMM, 1994, preprint volume, 18pp., 5 refs. A seismic risk assessment method has been developed for application to rockburst prone deep-level mining sites which have sufficient seismic coverage. The technique utilises several seismic hazard parameters simultaneously and assesses the seismic risk on a daily basis according to the individual levels of these parameters. Critical levels are determined from investigation of the long-term behaviour of the parameters in relation to recorded potentially damaging seismic events. The method has been applied to a data set comprising 15 months' worth of seismic data, with encouraging results

Aug 1, 1995

By J. Hu, F. Lin, R. Chen, F Peng, S. Yang, W. Yu

"Microseismic monitoring technology has become one of the most effective method of mine ground pressure monitoring after decades of development. But safety assessment of mine ground pressure by using microseismic monitoring is still in the development stage, it needs to be perfected continuously in practice, and choose the optimal assessment indexes and methods. The definitions and physical meanings of wave velocity, b value, and EI-VA value are introduced in this paper. Statistical calculation of the microseismic events in Luomu Mine is finished by using these indexes, then the functions and calculation results of V, b value, and EI-VA value with the variable of time are also given in the paper. The preliminary safety assessment method is established in Luomu Mine, and it has achieved good results in practical application.1.1 Engineering background The Luomu Mine is a super large molybdenum and tungsten production base in China, ore reserves is up to 2 billion tons, first in Asia and third in the world. It begins mining since the 1960. and bases on underground mining until 2002. In order to recover resources more effectively, it began to use opencast mining method and formed a production of 30000t/d in the early 1990. After about 30 years of underground mining, a large mined out spaces was formed under open pit mine, up to area of 1.2 million m2 and volume of 18 million m3, as shown in figure 1. The large number of mined out spaces seriously affects the normal production, mining and handling of mined out spaces are in the high risk. In the past years, several rock mass collapsions happened, and it caused a serious security threat to persons and equipments. According to the distribution characteristics of mined out spaces, Luomu Mine is divided into A, B, C, D and E mining area. The stability of D mining area is studied in this article. D mining area mainly includes 1376,1350,1340,1317 mined out spaces and 1280 deep large mined out area, as shown in figure 2. The mined out spaces of D mining area is extremely complex and high-risk. Therefore, a microseismic monitoring system was built to monitor the stability of D mining area, a large number of valuable datum has been obtained, and it has a striking effect (Cheng & Peng, 2013; Peng et al., 2013)."

Jan 1, 2015

By D. A. Buckingham

Engineering and economic evaluations were performed by the Bureau of Mines on 14 Frasch sulfur, 1 native sulfur, and 21 metal sulfide operations in 11 market economy countries. The evaluation included discounted-cash-flow rate-of-return economic analyses at 15 pct to determine the average total cost of production of these two commodities and the potential availability of elemental sulfur (8) and pyrite concentrate. The Bureau evaluated the potential availability of elemental sulfur and pyrite concentrate. Approximately 279 million metric tons (Mmt) of pyrite concentrate at 46 pct 8 is potentially recoverable from 422 Mmt of in situ metal sulfide ore. Nearly 89 pct of the total pyrite concentrate is available at an average total cost of production below the January 1984 pyrite concentrate market price ($43/mt). About 185 Mmt 8 is potentially recoverable from 253 Mmt of in situ elemental sulfur. About 99 pct of this sulfur is available at an average total cost of production below its January 1984 market price ($131/mt).

Jan 1, 1986

By F. E. Brantley

Research was undertaken by the Bureau of Mines to assess the technical feasibility of smelting cement-copper precipitate in an electric furnace to produce commercial-grade copper. The blister-grade copper produced in smelting was refined by gaseous oxidation and reduction methods to rive a product equal in quality to fire-refined copper. The cement copper used in the study was typical of the material produced in commercial operations. The sample product was received in a partially oxidized state and analyzed 77.5 percent Cu, 3.4 percent Fe, 0.8 percent Pb, 0.05 percent Ni, 0.6 percent Sn, and 0.9 percent S. Smelting tests were made on the precipitate using laboratory-size induction and electric-arc furnaces. Three types of furnace linings were tested during, the investigation: Carbon, including graphite; clay-graphite; and silicon carbide. Although all proved satisfactory, either carbon or graphite was preferred because of their superior refractory properties and low permeability to molten copper. Copper recoveries in the induction and arc smelting tests averaged 92 percent in commercial-grade metal assaying 99.8 percent copper. Refining the molten copper by oxidation and gaseous reduction or by chlorine lancing increased the purity to plus 99.9 percent.

Jan 1, 1961