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By M. Mikolás, L. Pomothy, K. Špakovská, M. Vanek

"Enterprises are faced with increasing economic competition and managers are obliged to look for methods that will ensure a competitive edge in their companies’ markets. These methods include managerial concepts that employ common sense and are low cost. One of these approaches is the KAIZEN methodology, of Japanese origin; kaizen means continuous improvement (CI) when translated. A mining company, despite some of its idiosyncrasies, is just an enterprise where the application of KAIZEN can be advantageous. The company investigated, OKD, is the only domestic producer of hard coal in the Czech Republic and operates four mines that produce 11 Mt of coal annually. The OKD management team opted for KAIZEN as their principal method of continuous quality improvement. This paper suggests ideas for development and application of processes that provide for continuing improvement of production and management. The authors have taken the OKD Company to be their benchmark in the field of mining activities. The paper also focuses on possible difficulties accompanying the introduction of CI sustainable methods. Three years of application of CI methods has increased the income of the company by almost US$38.1 million, which provides a strong argument for continued application."

Jan 1, 2015

By Levent Ozdemir, Bjorn Nilsen

For several recent TBM tunnel projects, unexpected ground conditions have been encountered, causing extra cost, considerable delay, and in some cases major claims. Undoubtedly, insufficient and/or irrelevant site investigation and testing are among the main causes of such incidents. The purpose of this paper is to review the main investigations and tests relevant for hard rock TBM projects, with particular emphasis on the considerable development that has taken place over the last few years. Also, guidelines for defining optimum scope and extent of site investigations and testing are discussed, as well as the importance of adjusting the investigations and tests according to complexity of the ground conditions and project type.

Jan 1, 1999

Plan de l?exposé ?? Présentation du site de la mine Restigouche et du mandat confié à Genivar ??Dénoyage de la mine ??Processus d?enlèvement des boues au fond de la fosse ??Utilisation de Géotubes dans le procédé à l?usine de traitement des eaux.

Feb 1, 2008

By Mark A. Jirsa

The Biwabik Iron Formation is a ~1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern- most extent by ~1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in iron-formation along the eastern part of what is known as the Mesabi Iron Range, and their potential liberation by iron mining has raised environmental health concerns. We describe here the geologic setting and mineralogic composition of the Biwabik Iron Formation in and adjacent to the contact metamorphic aureole of the Duluth Complex. The effects of metamorphism are most pronounced within a few kilometers of the contact, and decrease progressively away from it. The contact aureole has been divided into four metamorphic zones?each characterized by the composition and crystal structure of the metamorphic minerals it contains. The recrystallization of iron-formation to iron-rich amphibole minerals (grunerite and cummingtonite) and iron-pyroxene minerals (hedenbergite and ferrohypersthene) is best developed in zones that are most proximal to the Duluth Complex contact. ©2007 Elsevier Inc. All rights reserved. Keywords: Iron-formation; Mining; Fibrous; Mineralogy; Metamorphism.

Jan 1, 2007

By Dennis R. Dolinar

Controlling coal mine roofs subjected to high-horizontal stress conditions has always been difficult and uncertain. Traditional supports such as wooden cribs and posts, concrete donut cribs, and standing supports collapse and fail when the roof and floor move horizontally as mining progresses. The former U.S. Bureau of Mines (USBM) (currently the U.S. Department of Energy (DOE)), in cooperation with Western Fuels-Utah, Incorporated, conducted research to provide an alternative for traditional secondary support systems in a 3-entry gate road system subjected to high horizontal movements. The support system used in several other coal mine operations, consisted of internal high-strength galvanized resin-grouted cable supports. The system virtually eliminates the necessity for external crib, timber, or concrete supports. The support system consisted of 2.4 m (8 ft) full-column resin grouted bolts and 4.8 m (16 ft) long cable supports installed in conjunction with wire mesh and "Monster-Mats." Cable loading and roof deformations were monitored to evaluate the behavior of the immediate and main roofs during first and second panel extractions. Additionally, cable trusses were installed on the longwall headgate to protect the coal conveyance system from roof and pillar falls created by the formation of cutters and gutters. The test results indicated that the designed support system successfully maintained the roof during the extraction of two longwall panels and dramatically reduced the cost of secondary support. This paper describes the theory of high-horizontal roof movements, the advantages of vertical cable supports and cable trusses, and presents the roof and cable measurements made to assess the support performance during longwall retreat mining.

Jan 1, 1996

By N. A. C. Smith

The Bureau of Mines motor gasoline surveys have been conducted in January and July, during 1920 and 1921. The Bureau has obtained and analyzed samples of gasoline representative of that marketed in the larger cities. These surveys have indicated that the gasoline on the market during the winter months is more volatile than that sold during the summer months. Naturally, the motorist desires a more volatile gasoline in the cold winter months, as it affords greater ease in starting. The fourth semi-annual motor gasoline survey, conducted during the month of July, shows an interesting relation between the market price and the quality of motor gasoline. This is particularly evident if figures obtained today are compared with those of a year ago. At the time the Bureau of Mines conducted its summer survey of motor gasoline last year, the average tank wagon price of gasoline was 28.2 cents per gallon. This year it was 21.2 cents, a drop of practically 25%.

Jan 1, 1921

By J. B. Platt

Many utility fuel choices 1990-95 defied expectations, with utility decisions and coal market developments ever more closely linked. The Central Appalachian coal boom never occurred; clean-enough coal was developed in the hard-hit Midwest; Colorado-Utah coal surged; Pittsburgh seam production strengthened; utilities embraced Powder River Basin coal; and emission allowance prices collapsed. Competition drove productivity gains, but the future is not a simple repeat. Phase 2 brings fewer viable compliance options. Mega-railroad pricing has become a key risk factor -- will this be countermanded by merging utilities and power market competition? Revenue losses from vintage contracts are problematic. Uncertainty also plagues natural gas, in spite of unanimity across major forecasts, since recent experience has been so heavily influenced by the gas bubble.

Feb 24, 1997

By J. N. Van der Merwe

The paper provides an overview of subsidence research which was done by the Sasol Company in South Africa over a period of more than six years. The magnitudes of subsidence elements in South Africa are largely similar to those in the U.S.A. and Australia, as opposed to Europe. The research resulted in a subsidence prediction method with a new approach to the prediction of ground strain. The paper also describes the effects of subsidence on various commonly occurring surface structures such as roads, overland conveyor belts, pipe lines and power pylons. It is concluded that while most structures are not specifically designed to accommodate mining induced displacements, they can nontheless be undermined safely and economically with only minor precautions.

Jan 1, 1986

By R. W. Courtney

The objective of this study is to make a critical evaluation of the magnitude and extent of electrostatic hazards in typical U.S. mining operations and to assess the adequacy of techniques, materials, and equipment for detecting and minimizing these hazards. This was accomplished with an incident/accident survey, mine visits, literature search, and engineering analysis. It was concluded that it would be desirable to (1) utilize ground fault interrupters to minimize stray current from electrical utilities, (2) decrease the current and electrostatic sensitivity of electric detonators used in areas with a high incidence of lightning strikes or troublesome stray currents, (3) institute quality control and test standards for blasting material and protective devices, (4) establish an electrostatic monitoring program for loading ANFO in plastic lined holes, and (5) establish a risk criteria for operator exposure in mines.

Jan 1, 1982

By J. Matos e Silva

The paper refers two examples of structures located in seismic areas (Cases 1 and 2). The first one (Case 1) is the Torroal Bridge, located about 100 Km South of Lisbon, in the road Troia-Grandola. The horizontal loads due to the seismic actions were mainly carried by an anchor curtain connected, to the abutments, by reinforced concrete struts-ties. For the some purpose diaphragm walls were also placed under the pile caps of the column foundations. The second one (Case 2) refers to a building located about 50 Km South of Lisbon, at Sesimbra, near a cliff. To reduce the horizontal displacements of the structure due to seismic actions, in order to prevent the endangering of the cliff stability, an anchor curtain was adopted and connected, to the structure, by prestressed anchors.

Jan 1, 1996

Some design and feasibility studies have been made into possible methods of economic recovery of sulphur from smelter gases emitted at Western Mining Corporation's Nickel smelter at KalgoorIie in Western Australia. The smelter discharges some 330 000 tonne/yr of sulphur dioxide in a stream of approximately 6 per cent by volume of S02.Three possible recovery methods have been considered:1. The manufacture of sulphuric acid using the contact process.2. The concentration of sulphur dioxide to a pure form using dimethyl aniline as an absorbing medium.3. The reduction to elemental sulphur using natural gas as the reducing agent.Design studies were carried out by final year chemical engineering undergraduate students at Royal Melbourne Institute of Technology (RMIT) in 1981 under the supervision of the author and other teaching staff of the chemical engineering department. These studies indicate that sulphuric acid manufacture is the economically preferred recovery route.Markets for sulphuric acid include several potential mineral processing applications and the established fertiliser industry.Sulphuric acid is currently manufactured in a number of plants located at coastal regions of Western Australia using imported sulphur. The sulphuric acid is then used for superphosphate or titanium dioxide pigment manufacture at adjacent plants.The possibility is considered of manufacturing superphosphate at Kalgoorlie from locally produced acid obtained from the smelter gases and from phosphate rock railed to the site from the coast. The advantages of such a scheme include improved scale and technology of operation compared with some existing coastal operations, use of a waste material to replace imported sulphur, and avoidance of costs and hazards associated with railing large quantities of sulphuric acid.

Jan 1, 1983

The 106th Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the J.C. Lemmer Auditorium, SA National Museum of Military History, 22 Erlswold Way, Saxonwold, Johannesburg on Wednesday, 13th August, 2003. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations, also to recipients of awards, senior members of industry, Honorary Life Fellows, Past-presidents, our Members and other guests, among them the following: Kevin Moxham, President, Association of Mine Resident Engineers Prof. Jay Barton, Vice President, The Geological Society of South Africa Dr Gus Muller, President, Institute of Certificated Mechanical and Electrical Engineers, South Africa Marius van Rooyen, President, Institute of Mine Surveyors of South Africa Benjamin Ngulube, Deputy Vice President, South African Institution of Electrical Engineers Dr Francois Malan, Chairman, South African Institute of Rock Engineering Dr Paul Jourdan, President, Mintek

Jan 1, 2003

Future metal prices play a direct role in both the economic evaluation and short to medium planning of a mine scheduling sequence. It is difficult to predict with accuracy the future price of volatile metal commodities, however, it is possible to fix some future metal price, outside of long term contracts by the selling of futures contracts through a commodities exchange. The futures contract represents a fixed amount of a specified quality of a commodity for future delivery at a predetermined price. Several different types of hedging are possible, one in particular which is best suited for mining companies. There are relative advantages and disadvantages when trading in futures contracts and particular reference is made to gold contracts on the Sydney Futures Exchange.

Jan 1, 1980

THE Broken Hill mining field, approximately 31 miles in length, is at present being exploited by seven companies, viz. : North Broken Hill Limited, Junction North Broken Hill No Liability, Broken Hill Proprietary Block 14 Company, Broken Hill ProprietaryCompany Limited, Sulphide Corporation Limited, Broken Hill South Limited, and Zinc Corporation Limited.The variation in size and shape of the ore-bodies in the mines of these companies, together with the many alterations in pitch and dip, necessitates differences in methods of mining, each company working out its problem in its own particular way.In the matter of chute construction for the handling of the ore broken in the stopes, each mine belonging to the above companies has adopted a style particularly its own, though it may be said that one or two of the types approximate very closely to each other, slight minor differences only being noticed in the design. It is the purpose of this paper to give a brief description of the principal types of chutes now in use in th,e various mines on the field, and in doing so they may roughly be classified into three groups, viz:1. Bulk Chutes, 2. Circular Chutes, 3. Square-set Chutes.The Bulk type of chute is used in the North and British mines of the North Broken Hill Limited, the Central and Junction mines of the Sulphide Corporation, the South Blocks mine of the Zinc Corporation, and the Block 14 mine.The Circular type of chute is used by the Broken Hill South mine and the South Blocks mine.The Square-set chute is used in the Proprietary mine, the Junction North mine, and occasionally in other mines where the square set method of mining is a necessity, and more particularly as mullock passes.

Jan 1, 1925

By M. A. Trvits, M. Cummins, A. C. Smith, T. P. Mucho

This paper evaluates the effectiveness of remotely applied nitrogen-enhanced foam to aid in efforts to isolate and suppress a mine fire. The foam, in combination with a remotely-installed cementitious mine seal and a novel borehole pressure sampling methodology to determine the location of the suspected ignition source, was used to help control ventilation and inert the area surrounding the suspected ignition source by isolating it from oxygen. This allowed mine rescue teams to safely enter the mine, seal the area, and begin recovery operations to successfully return the mine to full production.

By Henry J. Kellner, Michael J. Brnich

This U.S. Bureau of Mines report addresses issues involved in using a limited number of training apparatus to give hands-on self-contained self-rescuer (SCSR) training to a succession of miners, and provides guidance regarding methods for minimizing the spread of infectious diseases. Procedures used for preventing the spread of infectious organisms in dentistry, cardiopulmonary resuscitation (CPR) training, and scuba training are examined. The sanitizing methods of three organizations that require individuals to insert the mouthpiece as part of the SCSR donning sequence are discussed. It was found that each of these organizations was able to render their mouthpiece assemblies microbe free simply and inexpensively.

Jan 1, 1989

New Zealand China Clays produces a unique halloysite clay product at Matauri Bay, Northland.   The company has licences over four deposits that were derived from the weathering of rhyodacite domes. Clay is mined and processed from two of the four deposits and is refined using a complex process based on gravity separation.   The product is almost entirely exported to niche markets in 24 countries. The main market is the fine ceramic industry where the product is used as a component in the manufacture of high quality porcelain and bone china bodies. The use of halloysite in these bodies gives the manufacturer the ability to achieve high whiteness and translucency. The other major market is for use in technical ceramics, where the product is sought after due to its high purity, fine particle size and stability at high temperatures.

Jan 1, 1997

By C. A. Rowland Jr

"I. INTRODUCTIONFred C. Bond's ""Third Theory of Comminution"" (1) was published in 1952. The mathematical statement of the Third Theory is the well-known Bond Formula:where W - Kw H per short tonWl - Work IndexP - Product size in microns which 80% passesF .. Product size in microns which 80% passesWork Index, as defined by Fred Bond, "" ... is the comminution parameter which expresses the resistance of the material to crushing and grinding. Numerically, the Work Index is the KwHrs per short ton required to reduce the material from theoretically infinite feed size to 80% passing 100 microns."" (2)Work indices for grinding can be obtained tram Bond grindability tests and can be calculated from plant grinding mill operating data when power consumed per ton of ore ground, the feed size analysis and the product size analysis are known.Work indices obtained tram Bond grindability tests, having been obtained from standard and controlled laboratory procedures, are reproducible and for the sample tested are accurate. The degree of accuracy relative to plant mill operation depends upon how representative the sample is of the total mill feed.The results of the Bond closed circuit rod and ball mill grindability tests (3) are given in grams of product sized material produced per revolution of the test mill. In developing a method to evaluate plant operating data and results from his grindability test, Fred Bond developed the ""Third Theory of Comminution."" In the process formulae were developed for converting grams per revolutionobtained from grindability tests to work index.The standard feed sizes for the Bond grindability tests are:Rod Mill Test ore crushed to minus 1ll inchBall Mill Test ore crushed to minus 6 mesh (Tyler)The formulae for converting grams per revolution to work index incorporate the 80% passing sizes for the feed to and the product produced in the specific test. Therefore, accurate work indices can be obtained from Bond grindability tests when the feed size is finer than standard. To obtain accurate test results, the ratio of reduction should be greater than 6 to 1."

Jan 1, 1972

By S. Jiansheng, H. Nakayama, D. Lu, A. Wang

ABSTRACT: New techniques and methods for 3D geo-mechanical model test are presented in this paper. The new model material NIOS with high density and low cost; the so-called DPSS (Discrete Principal Stress Surface) loading concept, the loading and monitoring system for the generation of the 3D initial stress field of the model test, also the special techniques and apparatuses for modelling the excavation of caverns located deep inside the model material, are developed and introduced. By adopting those new techniques, a very large 3D geo-mechanical model test with high comparability for a newly designed underground powerhouse has been successfully fulfilled. Key Words: 3D model test, underground group caverns, excavation process modeling. ZUSAMMENFASSUNG: Neue Techniken und Methoden für 3D geomechanischen Modellversuch wurden in diesem Artikel vorgestellt. Ein neues Modellmaterial mit hocher Dichte und niedrigem Preis, ein sogenanntes DPSS (Discrete principal stress surface) Ladenkonzept, ein Laden- und Überwachungssystem für die Erzeugung des 3D primären Spannungsfelds und überdies spezielle Techniken und Maschinen für das Ausbruch der tief in dem Versuchsmodell liegenden Kaverne wurden entwickelt. Bei Anwendungen dieser neuen entwickelten Techniken wurde ein sehr großer 3D Modellversuch mit großem Maßstab für ein geplantes unterirdisches Kraftwerk erfolgreich durchgeführt. Stichworte: 3D Modellversuch, unterirdischen Gruppekaverne, Ausbruchsmodellierung Résumé: le test de modèl de Nouvelles techniques et méthodes pour la géo-mécanique 3D est figuré dans ce papier. Le nouveau modèle de matériels NIOS avec la haute densité et le coût bas; la conception proposée de chargement DPSS (Discrete Principal Stress Surface), le système de chargement et de moniteur pour la génération de champs de stress initial du test de modèle, ainsi que les techniques et appareils spéciaux pour modeler les excavations de cavernes profondément localisées dans l’intérieur du matériel de modèle, sont développés et introduits. A travers l’adoptation de ces nouveaux techniques, le test de modèle de la géo-mécanique très large 3D avec la haute comparabilité pour actualiser une nouvelle étude de la centrale électrique sous-terraine a déjà accompli avec succès. Mots de clé: test de modèle 3D, groupes de cavernes sous-terraines, processus de modèle d’excavation

Jan 1, 2003

WHEN mining and treatment first started at Broken Hill only oxidised ores were available. These ores were rich in silver and lead-the silver mainly existing as chloride and the lead as carbonate.Treatment processes aimed mainly at the recovery of silver, lead being regarded as a by-product, and its recovery, except in so far as it affected silver recovery, was of minor importance.The first ore mined was carted to Terowie and thence railed to Melbourne, being smelted by the Intercolonial Smelting and Refining Co., of Spotswood.The first parcel (50 tons) returned £7442, or £148 16s. per ton to the Broken Hill Proprietary Company.The second parcel of 1053 tons, smelted at the Day Dream smelter, returned 132,142 oz. of silver, but no record is available as to its lead content.These results obtained from two parcels showed that by smelting the ore a handsome profit could be obtained, and Mr. La Monte was engaged to erect two 30-ton Nevada water jacket blast furnaces on Block 13. These furnaces were placed in charge of Mr. P...

Jan 1, 1928