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By Christopher Haycocks

Because of growing pressure from government and consumers to produce more coal, the mining industry must improve existing techniques and devise more efficient mining methods. Mining of the thicker, shallower and geologically superior coal seams in the western United States is being subjected to increasing pressure from environmentalists; and so in order to meet the demand, the coal industry is exhausting the more accessible surface seams and beginning to mine seam of over 1,000 feet in depth and less than. 30 inches in thickness. The longwall mining system is the natural choice for extracting deep and thin coal seams, as it operates almost independently of the overburden rock stress. Due to the added fact that longwall mining is an inherently more productive method than room and pillar mining, many coal producers are looking to it as a means of increasing productivity without a corresponding cost increase. The consistent rise in application of longwall mining in the United States in the last decade illustrates the excellent potential of this technique for the future. American mining conditions are geologically different from those in Europe where longwall mining has been highly developed and extremely successful. Although numerous successes have been recorded in the U.S. with this mining system, a substantial number of failures have also occurred. These failures are due primarily to roof control problems usually over the face, in the tail entry, or both. Another problem area for American operators contemplating the use of this method has been correct selection of equipment, which should be custom fitted to local mining conditions for optimum productivity. It is essential that correct estimates for chock resistances, support densities, supported and unsupported roof spans, as well as rates of advance and length of working faces be provided to optimize mining conditions. Unless extensive pilot projects are planned engineers must choose their equipment correctly at the outset. A typical investment in longwall equipment will amount to several millions of dollars.

Jan 1, 1979

By James F. Reynolds

Introduction There are 1.4 Gt (1.5 billion st) of recoverable coal under less than 914 m (3,000 ft) of cover in Colorado in pitching seams. Snowmass Coal Co., in cooperation with the US Department of Energy, introduced the longwall mining method in pitching seams to North America. This venture is a coal mining research program directed toward the profitable production of coal under difficult mining conditions as found in pitching seams of the western US. Snowmass Coal classifies pitching seams into the following categories for longwall on the strike in seams 3 m (10 ft) or less thick: • Flat = 0 to 10°: Normal continuous mines and shuttle cars work efficiently. • Slight = 10° to 22°: The maximum pitch that rubber tired equipment will function. • Moderate = 22° to 40°: The angle of repose of mined coal. • Steep = 40° to 60°: The limit of safe use of this roof support. • Vertical = over 60°. The longwall roof support covered here will work in all pitches except vertical. The shearer and conveyor will work in flat through moderate conditions. Longwalling across strike with this equipment in seam pitch over 60° could be accomplished with an inclined face. Development of the first longwall panel began in 1979 and was completed in 1981. The longwall equipment was installed and mining began on Aug. 11, 1981. Mine Planning and Development The original mine plan took advantage of old works abandoned in the 1960s. The gates were developed on a two-entry system with the entries rising 2° to the strike, allowing water to drain from the face. The mining method was by Alpine F6A road header continuous miners with bridge conveyor type coal transport into 5.4-t (6-st) bottom dump coal cars hauled on 1.1-m (42-in.) gauge track by 7.2-t (8-st) battery locomotives. The initial concept was to haul coal from the longwall by battery locomotive. Lack of discipline, however, was shown in the irregular direction of the gate entries, and local rolls in the coal seams severely limited the capacity of battery locomotives. Current mining law prohibits using an intake escapeway for belts or trolley locomotives. A two-entry system is the simplest method of panel development in a pitching seam. A continuous miner cannot be trammed from one entry to another because of steep "X" cuts. Thus, the development requires a continuous miner in each entry. The configuration of the old mine works resulted in a first panel longwall block of three 108 m x 1.6 km (355 ft x 5,400 ft). In panel development, the use of battery locomotives for coal hauling became evermore costly. When the panels were completed and the setup room finished, the lower gate entry was changed to a belt entry and battery locomotives were abandoned. A new slope was driven and the mine supply system was converted to rubber tire diesel supply. The latest generation of roadheader and standard high powered shuttle car-to-belt system is now used for development. Selection of Longwall Equipment Longwall mining across the strike on pitching seams is currently practiced in many nations. Equipment similar to that used by flat seam longwalls is available for pitching seam use in Great Britian and Germany. Face equipment includes a twin outboard armored face conveyor. It was selected to give maximum retention of coal on the conveyor due to flight rigidity and to prevent coal from sliding down the face and jamming the lower belt gate. Also selected was a 22-mm (0.9-in.) Dowty twin-outboard face conveyor for a 106-m (350-ft) face with a single 112-kw (150-hp) drive

Jan 12, 1983

By E. S. Moore

ALTHOUGH nickel was in use in alloys long before the Christian era, the metal was not discovered until 1751, when Cronstedt recognized it in niccolite from Sweden. The Chinese apparently used a nickel alloy, known as "pahfong" thousands of years ago and Persian coins dating farther back than 200 B.C. consist of a copper-nickel alloy similar to some of those now in use in coins. The pure metal was first prepared about 1775 and the metal was refined for commercial purposes some years later. The nickel industry did not attain much prominence until the ores in New Caledonia were discovered. Exports of ore from that country began in 1875 and since that date there has been an ever-increasing world output of nickel and a great expansion in the uses of the metal except during short periods of commercial and industrial depression. Previous to 1875, for a number of years, Norway was the chief producer, although the metal was mined also in Sweden, Finland, Italy, Germany, Austria, France, China, the United States and other countries. With the dis-covery of nickel deposits in the Sudbury district, Ontario, a new factor was introduced into the nickel industry and Sudbury has since become the overwhelmingly dominant feature in the world's nickel markets. Although nickel was first discovered in Canada as early as 1848 near the north shore of Lake Huron and nickel-copper sulfides were found in 1856 by surveyors working close to the present location of the important mine at Creighton, in the Sudbury field, it was not until 188.3 that any importance was attached to this field. In that year copper sulfide attracted attention where the main line of the Canadian Pacific railroad was being projected across Canada to the Pacific coast. Mining began near this discovery in 1889 but in the meantime operations had begun in 1886 in other parts of the field and by 1890 about 100,000 tons of ore had been raised. In the Sudbury field, as in Norway and at the old Lancaster Gap mine in Pennsylvania, the ore was first mined for its copper content and difficulty in the refining of the copper led to the discovery of the important proportions of nickel in the ore. No. 3 property of the Inter-national Nickel Co., now known as the Frood, the greatest deposit in the

Jan 1, 1932

By L. J. Blatnica

Throughout the 1980's the tem Mine-Wide Monitoring System has had various meanings for manufacturers of these systems and underground mine operators alike. System suppliers had visions of grandeur in the early 80's as they envisioned each mine, that has more than a single section, installing a computer based monitoring system to provide surveillance, control and documentation of the entire mining operation, including everything from a single heat detector to the weekly payroll. In a few cases this may have become reality but the truth is these systems have quietly become a steady but unspectacular workbase for the modern mining industry of the 1990's. As it exists today the total market for underground monitoring systems may not exceed $10 million annually. Suppliers have lowered their expectations of the dollar value of this particular market. Some were entering a new market because of experience with computer based data acquisition systems. Others had been active in the mining industry for years with more traditional equipment (communication systems, methane monitors, safety equipment, etc.) and decided to become involved with Mine-Wide Monitoring Systems.

Jan 1, 1990

By R. B. Bauder

In connection with a Bureau of Mines research program on utilization of Cuban lateritic ores, a comprehensive review was made of the chemical literature on nickel and cobalt. Initially, the review had as its objective the selection, from the voluminous literature dealing with the chemistry of these two metals, of only those references to reactions that were especially pertinent, or at least closely related, to the field of extractive metallurgy. Later, the coverage was extended to include references to the techniques and plant applications of extractive metallurgical procedures for the recovery of nickel and cobalt. In this report, the period from January 1929 to July 1955 has been covered, as it seemed logical that recent literature should be of greatest value. This cutoff date was established in order that the bibiliography could be issued at an early date, inasmuch as currently much work is in progress on the lateritic ores. Later, a supplement will be prepared extending the coverage to about 1900.

Jan 1, 1957

By Robert B. Fulton

Summary of data and estimates for 52 fluorspar properties in the following 13 foreign countries: Mexico Thailand China (PRC) Morocco Tunisia Italy Spain South Africa France United Kingdom Kenya Namibia Federal Republic of Germany Data includes deposit type, resource tonnage and grades, mining and beneficiation methods, annual production, fluorspar products and by-products, manpower requirements, capital and operating cost estimates. For operating properties, engineering and cost data have been developed for present and anticipated levels of production. Hypothetical operations have been assumed for undeveloped deposits.

Jan 1, 1984

By F. Albayrak

This report is a study of the impact of Federal laws and regulations on the domestic supply of metallic and nonmetallic minerals. The study was confined to pertinent environmental legislation and the recently enacted Federal Mine Safety and Health Act of 1977. Emphasized were the legal requirements placed on individual selected mineral industries, and the economic impact of these requirements. A certain amount of attention was also directed to the particular environmental and health and safety problems generated by selected mineral industries. The study also pinpointed a list of major problem areas having significant impact on the domestic mineral supply.

Jan 1, 1978

By N. E. Lehman

Cordilleran metamorphic core complexes in the southwestern United States are areas where middle to late Tertiary low-angle normal faulting has uncovered rocks that were at temperatures sufficient for mylonitization during the early part of Tertiary extensional faulting. Large-displacement low-angle normal faults that separate upper-and lower-plate rocks in metamorphic core complexes are termed detachment faults. The significance of Tertiary detachment faulting in the Basin and Range Province has only become apparent in the past 6-8 years, and the association of mineral deposits with detachment faults has only been recognized in the past few years as well. Crystalline rocks below detachment faults have typically undergone chloritic alteration and brecciation over a distance of a few to a few hundred meters below the fault surface (Fig. 1). Chloritic alteration and brecciation overprinted mylonitic fabrics formed during earlier ductile shearing along the down-dip projection of detachment faults. Rocks that underwent pre-Tertiary ductile deformation and prograde metamorphism were subjected, in rapid succession, to middle to late Tertiary mylonitization, brecciation and chloritic alteration, microbrecciation immediately adjacent to the fault, and subaerial exposure. Lower-plate rocks thus experienced rapid decompression and cooling as a result of tectonic denudation and isostatic uplift (Wernicke, 1981; Davis, 1983; Davis et al., 1986).

Jan 1, 1987

THE solid nonmetallic inclusions that are present to some extent in all commercial steels have been variously designated. In early references they were usually called slag inclusions, and. this terminology is still retained to some extent. On the premise that all nonmetallic matter produced in a metallurgical process is slag, this can be justified. We have come to think of slag, however, in a more restricted sense, and calling these particles slag inclusions is further objectionable because it fosters the erroneous concept that they are actually incorporated portions of furnace slag. Rarely is this true. The term sonims (coined from solid nonmetallic impurities) was proposed many years ago but never came into common use. In general the term "nonmetallic inclusions" seems to be satisfactory and adequate. NATURE AND CONSTITUTION OF NONMETALLIC INCLUSIONS From the standpoint of origin, inclusions fall naturally into two classes: (1) those that occur as a result of reactions taking place in the body of the molten or solidifying metal and (2) those that result from the mechanical incorporation of refractories or other materials with which the steel comes in contact. The former are by far the more numerous and have been called indigenous, natural, or native inclusions. The latter are by their very nature sporadic in occurrence and have been called exogenous, accidental, adventitious, or foreign inclusions. They are often referred to as the "slag stringer" type, though here also the material is not likely to be furnace slag. Substances Found in Inclusions. Nonmetallic inclusions are composed principally of oxides and sulphidea but carbides and nitrides sometimes play an important role. In the case of indigenous inclusions the reactions by which these particles are precipitated from the molten or solidifying steel may be caused by (1) oxidation such as may occur during refining or during tapping and teeming, (2) deoxidation by added alloys, (3) change in equilibrium constants as the steel cools to the freezing temperature, (4) decreased solubility with lower

Jan 1, 1944

By J. E. Johnson

Discussion of the paper of Prof. Henry M. Howe, presented in abstract by Bradley Stoughton at the Cleveland meeting, October, 1912, and printed in Bulletin No. 71, November, 1912, pp. 1181 to 1227. J. E. JOHNSON, JR., Ashland, Wis. :-This material is largely beyond the understanding of most of us practical men, but there are certain portions of that diagram that are of enormous importance. We have been conducting a, very extensive investigation of the quality of charcoal-iron and of all iron, and we have found that this eutectic point here (indicating on chart) is a sort of balance point between the good irons and the bad ones, and I have some slides to show what practical results we have found depending on this point here on the d diagram; and it would be a mistake for men who were -concerned with operation and were getting practical results, to think that these things are of no importance. They are exceedingly hard to understand, and I confess that a great deal of them is beyond me, but there is no doubt that the quality of iron depends to an enormous extent on the location of the carbon content of the iron to the right and left of this point, and the position of that point is dependent upon the silicon, and I wish to make a plea to the practical and operating members of the Institute not to disregard this material on account of its being highly scientific, because I hope to show later that there are matters of the highest practical importance that depend directly upon certain portions of this diagram. HENRY D. HIBBARD, Plainfield, N. J. :-T understand that washed metal, which, is practically pure iron and carbon, does not solidify at one instant, is cast-iron does, but passes through a mushy stage. That has been an enigma as to how and why it did so, and possibly some light might be thrown on it in this connection. BRADLEY STOUGHTON, New York, N. Y.:-If Wittorff's propositions are accepted, washed metal containing more than 4.1 per cent. of carbon would begin to solidify as liquid plus Fe4C

Dec 1, 1912

By GJ Hundman

The Multiple Unit Continuous Haulage (MUCH) System was designed to provide the capacity to continuously convey coal from the mining machine to the main haulage belt. The MUCH System has an operator who steers the lead vehicle, ever following the mining machine. All the remaining vehicles follow the path of the lead vehicle, with their conveyors automatically lining up between the lead vehicle and mine section panel belt. This is accomplished by mechanical linkages on the vehicles which are interconnected by steering bars between vehicles (patent pending). The MUCH System has an operator who steers the discharge vehicle when outby travel is required. Outby travel is just like inby, with each vehicle following the path of the preceding vehicle. Surface tests overwhelmingly indicate the "UCH System should track/retrack successfully in square pillar underground room and pillar coal mines with 18 ft. wide entries and slopes up to 10 percent. For 60 degree pillar plans the minimum entry width required is 15 ft. Surface tests also indicate the MUCH System will convey over 8 TPM of coal around 90 degree corners without excessive spillage.

Jan 1, 1983

By A. H. Lang

Introduction The recent uranium discovery at Theano point, lake Superior, is probably a rediscovery of the first reported Canadian uranium occurrence. A description of material from the original discovery was published in 1847 by J. L. LeConte, and many attempts have been made to relocate the deposit. Such attempts have in the past been unsuccessful because of vagueness in the original description of the locality. Besides being a prospect that seems to merit development work, the Camray discovery is important because it reaffirms the occurrence of pitchblende in the eastern part of the Precambrian shield. Much staking followed the announcement of the discovery, and some additional finds have been reported. Location The Camray discovery is at the shore of Theano point, lake Superior, about seventy miles north of Sault Ste. Marie (see Figure 1). It is in township 29, range XIV, district of Algoma. The showing is two miles from Highway No. 17, and is reached by a rough trail that leaves the highway at mileage 72.9 from Sault Ste. Marie. There are no towns of any size nearer than Sault Ste. Marie.

Jan 1, 1949

By Tim O’Neil

More than 5,300 mining professionals from around the world attended the SME Annual Meeting and Exhibit, March 1-3 in Denver, CO. Seventy three technical sessions highlighted innovative technologies and applications for the development of mineral resources. And the exhibit featured 421 companies worldwide and 632 exhibit booths. The 1999 SME Annual Meeting had 10% international attendance. Professionals from outside the United States were guests at the first SME International Reception.

Jan 1, 1999

By W. W. Krech, T. E. Perkins

As fractures are propagated through rocks, energy is absorbed near the extending crack tip. Apparent surface energies for several rocks have been measured by cleavage under dynamic con-ditions. At nominal crack velocities from 0.5 to 500 in (min, measurements showed that fractures propagated in discrete jumps. Calculated surface energies and moduli were relatively insensitive to nominal rate of cleavage. in another set of experiments, rocks were cleaved under high confining stresses. The rocks were submerged in low leak-off fluids which formed a filter cake on the freshly cleaved surfaces (similar to the hydraulic lracturing process). Apparent surface energies were increased substantially as the surrounding fluid pressure was increased. Moduli in bending increased significantly upon application of the first 1,000 psi but were insensitive to stress level at greater pressures. INTRODUCTION For almost 20 years, hydraulic fracturing processes have been utilized effectively to stimulate oil and gas wells. During this period, some process improvements have resulted from studies of fracture orientation, mechanics of fracturing, areas generated, conductivities of cracks, etc. Yet many questions remain concerning the conditions and pressures needed during fracture propagation. In this paper we will report additional studies of the mechanics of fracture extension. It was shown previously3 that large rock samples could be cleaved under controlled conditions so as to measure the apparent surface energy (that amount of energy absorbed per unit area of new surface created). In this paper we consider the effects of two additional factors on surface energies, viz.: (1) effect of cleavage rate and (2) effect of confining stress level. THEORY Cleavage experiments were conducted on rock samples similar to that illustrated in Fig. 1. Blocks of rock several inches wide, 2- to 3-in. thick, and up to 3 ft in length were grooved longitudinally with shallow guide slots. A crack was initiated and allowed to extend along the web as the top of the rock specimen was pulled (or pushed) apart. Auxiliary equipment permits the measurement of (1) force applied at the top, (2) separation at the top and (3) crack length. (Further experimental details will be given in the next section.) The rock beams created by the crack are considered ton be cantilever beams. The deflection (or separation of the rock beams) at any point is calculated 4,5 by the beam Eq. 1.

Jan 1, 1967

By Peeler P. K

The recent renewal of interest in hydrometallurgical routes for copper production has been brought about by the possible future reliance on mixed ores and lower grade deposits, environmental aspects, and energy considerations.A number of hydrometallurgical processes for the recovery of copper have recently been proposed. Flowsheets are developed for two processes which incorporate several treatment methods being experimentally studied in Australia.In the first process a cupric chloride leach is followed by electrowinning whilst the second is based on the formation of cuprous ions, stabuized by acetonitrile and subsequent disproportionation to cupric ions and metallic copper. For the purpose of comparison, flowsheets were also developed for the Arbiter and Cymet processes.Process economics are estimated for the four processes and the results are discussed in relation to competitive pyrometallurgy. None of the four hydrometallurgical processes, with possible exception of the Cymet process, appears to be competitive with established large scale and newly developed pyrometallurgical processes for chalcopyrite.However, because the economics of the individual hydrometallurgical processes depend strongly on specific conditions, a "tailored" process may be competitive with pyrometallurgy in particular circumstances.

Jan 1, 1977

By D. T. Bergado

The uppermost subsoil profiles of the Bangkok plain can be divided into four layers, namely: weathered clay, soft clay, stiff clay, and dense sand layers. The soft Bangkok clay is a normally consolidated marine clay with built-up preconsolidation effects and overlain by a weathered crust. Up to the present, a large number of full-scale tests on excavations and pile foundations has been made by numerous investigators. Based on these results, the available data are reviewed and evaluated. The results show that for test excavations, the excess pore pressures were overpredicted by the existing theories. The vertical and lateral movements in the excavations can be predicted by the bilinear and non-linear finite elements using appropriate modulus values. Relationships among probability of failure, safety factor, and safety margin of the excavation were also obtained. In the case of pile foundations, good agreement between the measured and predicted ultimate pile capacities were obtained for long piles. The adhesion factors ranged from 0.4 to 1.0 while the average skin friction factor was found to be 0.33. The ultimate capacity of the pile was also predicted successfully by using the Dutch cone data. For lateral deflection of piles, Davisson and Gill's theory predicted well in the low deflection zone while Poulos' theory agreed well in the high deflection zone. From the probabilistic analysis of ultimate pile capacity, the probability of failure was related to the central factor of safety. The piles usually used in Bangkok area are mainly precast concrete piles

Jan 1, 2010

By G R. Ballantyne, M S. Powell

A comprehensive Australia-wide survey of comminution energy consumption at copper and gold mines was presented by the authors at the 11th AusIMM Mill Operators’ Conference 2012. The database has been extended to include major overseas mines and used to benchmark comminution energy consumption across the industry. The mines included in this study now represent 15 and 24 per cent of the total global gold and copper production respectively, and almost all Australian production. The comminution energy intensity per unit of saleable metal has been presented in a graphical form similar to a cost curve used in economics. The graphical method has been developed to assess the competitive advantage that can be achieved by reducing comminution energy intensity.This benchmarking tool has been applied to three published case studies to assess its applicability. The first case study indicated that a large reduction in size-specific energy (kWh/t -75 µm) was achievable by converting standard semi-autogenous and ball mill circuits to include high pressure grinding roll and stirred mills. The second case study investigated the metal-specific energy reduction historically achieved by Bougainville with the addition of a preconcentration screening plant. The final case study was conducted by Barrick Gold Corporation and involved incremental efficiency upgrades at three of its gold mines: Cortez, Cowal and Mara North. The application of the benchmarking tool to each of these case studies successfully demonstrated the scale and competitive advantage that was achieved by reducing energy intensity.CITATION:Ballantyne, G R and Powell, M S, 2014. Benchmarking comminution energy consumption for improved efficiency, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 95–100 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Mervin D. Marshall

A quick-reaction, mine permissible rescue vehicle (MERV) was developed for use by rescue teams. The MERV is a 6-wheeled, battery-powered unit with life support equipment and instrumentation; designed for a two-man team, with provisions for handling two victims or tools in a trailer. The vehicle is 100 inches long, 56 inches wide, and maximum height of 34 inches. It can be lowered down most mine shafts and has clearance to travel mine railways. The vehicle has power to all six wheels with power transmitted separately to either or both sets of wheels. Low-pressure, high-traction tires give the vehicle the ability to handle soft, muddy mine floors, flooded areas and significant obstacles, and can negotiate a 45% grade. Power and life support are sufficient for a 4-hour mission. The life support system is a commercially-available, approved unit currently used by MESA rescue personnel. A payout wire system provides communication between the vehicle and home base over a distance of 10,000 feet. On-board monitoring of carbon monoxide, methane and oxygen is provided, with master and individual alarms to warn of gas concentrations outside pre-set limits. A lightweight, water-tight trailer was developed for carrying victims or hauling tools and equipment.

Jan 1, 1979

By Grant Buma

Groundwater restoration is an uranium leaching. Information on the technology, costs, and the current permitting regulations is of vital operators and to firms considering in important aspect of in situ effectiveness of the current state and federal government importance to in situ leach situ leaching. This study, funded by the U. S. Bureau of Mines, describes: (1) all recent restoration attempts at commercial in situ leach operations, (2) restoration costs reported by the industry, (3) empirical equations that predict the amount of groundwater flushing required to meet the current restoration criteria, and (4) in situ uranium permit requirements for the states of Texas, Wyoming, New Mexico, Utah, Montana, Colorado and South Dakota, and Federal requirements.

Jan 1, 1981

By C. Frenzel, N. Blechschmidt

"INTRODUCTION There is no doubt about the time and effort companies put in establishing and maintaining their equipment. However, the question about how these companies can map the benefits comes up. Neither do they have the tools to quantify the benefit of their action, nor do they have the tools to know the actual quality of their current maintenance system. The resources used in the process seem futile to observers. It seems impossible to trace improvements and to get information about the impact of actions in retrospect. Improvements in maintenance performance cannot be recognised by management or shareholders. Thus the necessity for measuring the performance of maintenance systems is given. In this paper ConMoto is systematically showing the strengths and weaknesses of many companies' maintenance management and is providing field-tested proven design elements for measuring maintenance systems and implementing Value Oriented Maintenance. Considering only business assets in production facilities and related machinery out of all investment goods in Europe, you reach a value of around 9.7 trillion euros in 2008. In Germany alone the equipment replacement value amounted to about 1.9 trillion euros [8,10,11,13]. If you calculate a cross sector maintenance costs rate of 4.8 % (corresponding to the average value identified in this study), direct maintenance costs in European production locations add up to over 450 billion euros per year [3]. These figures speak for themselves. Yet maintenance is not only of enormous significance for European enterprises. Our experiences show that maintenance and asset management, particularly sustainability issues, are also increasingly moving to the forefront in the BRIC states, in the Middle East and in many emerging countries. First of all, in order to meet the resulting high quality and cost related requirements of maintenance systems, a comprehensive overview of the issue is needed. This overview is provided by a detailed analysis of 83 companies and production plants from various sectors – with amazing results. SIGNIFICANCE OF MAINTENANCE Current studies show the high financial significance of maintenance and asset management. According to the market study in the Asset Manager [9], in industrialised countries about 10 to 15 per cent of the labour force are employed in maintenance and facility management tasks. In Europe about 40 to50 million people are directly and indirectly involved in retaining the value of machinery, plants, buildings, transport systems and infrastructure facilities. A glance at the costs side also demonstrates the great relevance of maintenance. EU-wide annual direct maintenance costs amount to a total of more than 1,500 billion euros. In Germany alone they are about 250 billion euros. This impressive total is considerably exceeded by indirect maintenance costs caused by technical failures. Indirect costs are estimated to be five times higher (Figure 1). [7,12,14]"

Jan 1, 2018