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By Bruce D. Hansen

For many years, Newmont has focused on improving its operations. After the merger between Newmont and Santa Fe Pacific Gold, Newmont created synergies of more than $50 million a year in Nevada. This was done primarily through optimal ore movements and consolidation of various functions. During the current period of low gold and copper prices, Newmont has refocused its efforts on efficient operations worldwide. At its mine facilities in Nevada, Newmont has used a combination of several strategies to decrease the costs of operations and to increase profitability. These include computer technology, optimal use of infrastructures, procurement strategies, functional consolidation, enhanced mine planning and several available metallurgical processing options.

Jan 1, 1999

By C. W. Whitten

Iron ore deposits in south-central Missouri have emerged as a possible resource for the rare-earth elements. The Pea Ridge Iron Mine is one such deposit. Rare-earth minerals at the Pea Ridge Iron Mine are contained in breccia pipes consisting primarily of silicon oxides and feldspars. These pipes extend up through the magnetite ore body and appear to be alterations and replacement of earlier hematite. The mineralogy of these pipes is very complex and varied, which could complicate the concentration and extraction of the rare-earth minerals. This U.S. Bureau of Mines !eport represents a study by characterization of the mineral phases to assess the amenability and development of concentration and extraction techniques. Previous characterization of rare-earth minerals has been mainly by transmitted light microscopy. This method along with reflected light microscopy, scanning electron microscopy, and X-ray diffraction was used to identify and characterize the rare-earth and associated minerals. The minerals identified were the major ore minerals, magnetite and hematite; the rare-earth phosphates, monazite and xenotime; the rare-earth silicate, allanite; the minor associated minerals, cassiterite, pyrite, and apatite; and the gangue minerals, feldspar, quartz, and actinolite.

Jan 1, 1990

By Stanley Lefond

The health of the industrial minerals industry appears to be improving year by year. In fact, preliminary information suggests that only three commodities (asbestos, bromine, and sulfur-other) failed to show a production gain in 1984 over 1983. In 1983, 10 commodities failed to post gains and six remained constant. The total value of industrial mineral production in 1984 was $16.7 billion, up $1.4 billion from 1983. Cement, clays, gypsum, and crushed stone production increased. Since these are used in housing and construction, this suggests these industries are moving out of their recent doldrums. Barite and clay production also improved in 1984. Local US barite production, however, still has a long way to go to attain the 1981 high of 2.6 Mt (2.9 million st). Barite imports remain high. But they are not as high as the 1982 importation of 2 Mt (2.3 million st). Bentonite production in 1984 increased 20% in volume and 25% in value over the previous year. This suggests improvement in the drilling industry and an increase in demand for iron ore pelletizing grades. All in all, the industrial mineral industry is alive and well. And it shows signs of great improvement in the next few years. Many thanks to those industrial mineral technical committee members for their assistance in assembling this industrial minerals review: M. F. Dibble, H. W. Allen, G. H. Gallup, S. G. Ampian, D. W. L. Spry, H. G. Fleshman, and L. J. Czel.

Jan 5, 1985

When Haematite Explorations Pty. Ltd. began prospecting for petroleum in 1960, there was only ill-defined geological evidence on the land bordering Bass Strait to support the belief that petroleum lay trapped in sedimentary formations beneath its shallow waters.A reconnaissance of the area, made in 1961 by the airborne magnetometer method, covered the waters and islands of the Strait and overlapped the Victorian and Tasmanian coasts. The survey indicated the presence of the Bass Basin (which is completely water-covered), assisted in outlining the Otway and Gippsland Basins, and showed that each basin contains sedimentary rocks over 10,000 ft thick. Information on the regional geology and minor volcanic activity was also obtained.Marine seismic surveys carried out from 1962 to 1965 defined these basins more accurately and showed the nature and structure of the thick sedimentary sections.Correlation of the seismic data with onshore wells identified the sediments as Tertiary and Mesozoic. Subdivisions of the former in all basins and the latter in the Otway Basin were made. These Tertiary and Mesozoic rocks are not seriously deformed and they have good prospects of containing petroleum.Possible structural and stratigraphic traps, recognized from the seismic record sections by petroleum geologists, are being tested by offshore drilling which began in 1964.

Jan 1, 1966

By D Cumming-Potvin, S W. Jacobsz and E Kearsley, J Wesseloo

This paper describes a physical modelling program that recreated block cave propagation in a geotechnical centrifuge. A brief description of the design of the test along with the sample material and monitoring equipment is given. The samples tested showed caving behaviour and fragmentation distributions that one would expect from caving mines, with one cave deviating due to pre-existing major discontinuities in the sample. A series of fractures formed ahead of and parallel to the cave, implying that an extensional failure mechanism may play a larger role in cave development than previously thought. The results of acoustic emission monitoring of the tests show a seismogenic zone advancing ahead of the cave; however, the quantity and quality of the data is too limited to draw any further conclusions.CITATION:Cumming-Potvin, D, Wesseloo, J, Jacobsz, S W and Kearsley, E, 2016. Results from physical models of block caving, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 329–340 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Zach Ahinga, Mike McRae, Dave Hopkins, Steve Klein

The San Vicente Pipeline project involves the construction of an 8-1/2 foot diameter water pipeline in an 11 mile long tunnel in San Diego, California. The tunnel will be excavated in extremely variable geologic conditions consisting of strong granitic and metamorphic rocks, weak sedimentary rocks, abrasive conglomerates, and mixed face conditions. This paper discusses the challenging geologic conditions and some of the key design evaluations for the project. Currently design work for the project has been completed and construction will be underway by mid-2005.

Jan 1, 2005

By K. J. Liles

The U.S. Bureau of Mines evaluated the physical properties of ceramic particulate composites made from titanium nitride (TiN), alumina (AI203), and aluminum nitride (AlN) as part of a program to meet the high-performance demands on structural materials for new and emerging technologies. Samples containing from 20 to 80 wt pct TiN were pressed and fired, and their composition, Vickers hardness, modulus of rupture (MOR), and fracture toughness were determined. X-ray diffraction and scanning electron microscope (SEM) analyses showed that, depending on the amount of TiN added, the microstructure of the samples consisted of either a titanium-aluminum-oxynitride (TiAlON) particulate in a spinel matrix or a spinel particulate in a TiAlON matrix. The best results of the physical tests were achieved on a mixture of 40 wt pct TiN, 30 wt pct A1203, and 30 wt pct AIN. Sintering aids were added in 1-and 3-mol-pct increments to the 40-30-30 mixture to determine their effect on microstructure and physical properties. Results of an analysis of variancf' on a 4 by 4 factorial analysis showed significant effects on density, MOR, and Vickers hardness.

Jan 1, 1989

Sulphide minerals, such as pyrite and sphalerite, are leached by ferric sulphate. This reaction produces ferrous sulphate and other dissolved products. The ferrous sulphate is re-oxidized to ferric sulphate by bacteria. These reactions can be written as: [ ] However, in 1964 Silverman and Ehrlich proposed that this is not the only role that is played by bacteria. These researchers proposed that T. ferrooxidans enhances the rate of oxidation of pyrite above that achieved by chemical reaction with ferric sulphate at the same solution conditions. This enhancement in the rate of dissolution was proposed to occur by direct microbiological action, possibly by the extra cellular secretion of an enzymatic oxidant. Since the Silverman and Ehrlich proposal, different authors have made opposing claims concerning the action of T. ferrooxidanson pyrite. This ?direct mechanism? of bacterial dissolution of pyrite can be given by the following reaction: [ ]

Jan 1, 2000

By M. Kwasniewski, M. Takahashi

Prismatic samples of a medium-grained sandstone from Slask Colliery (Upper Silesian Coal Basin, Poland) were tested under uniaxial compression, conventional triaxial compression and true triaxial compression conditions. The conventional triaxial compression tests were carried out at confining pressure (p) equal to 12.5, 25.0 and 37.5 MPa. In the true triaxial compression tests the minimum principal stress (s3) was equal to 25.0 MPa and the intermediate principal stress (s2) was 1.5, 2 and 2.5 times higher than s3. Results of the studies show that confining pressure strongly inhibited dilatant behavior of rock samples tested under conventional triaxial compression conditions; the increasing confinement resulted in the growing compaction of the rock material. The effect of dilatancy was also highly suppressed by the intermediate principal stress. While important dilatant, negative volumetric strain corresponded to the peak differential stress at low intermediate principal stress conditions, at high intermediate stresses the rock material was damaged to much lesser extent. As a result, faulting of rock samples in the post-peak region was much more violent and was accompanied by a strong acoustic effect. Les échantillons parallélépipédiques du grès à grains moyens de la mine ‘Slask’ (Bassin Houiller de Haute Silésie, Pologne) ont subi les essais de compression monoaxiale (compression simple), de compression triaxiale conventionnelle (compression triaxale de révolution) et de compression triaxiale vraie. Les essais de la compression triaxiale conventionnelle ont été effectués à la pression de confinement de 12,5, 25,0 et 37,5 MPa. Dans les essais de compression triaxiale vraie la contrainte principale minimale (s3) était de 25,0 MPa et la contrainte principale intermédiaire (s2) était 1,5, 2 et 2,5 fois supérieure de s3. Il résulte des essais que la pression de confinement inhibe fortement le processus de dilatance dans les échantillons testés dans les conditions de compression triaxiale conventionnelle; l’augmentation de la pression provoquait l’augmentation du compactage du matériau rocheux. Le phénomène de dilatance était également limité de façon significative par la contrainte principale intermédiaire. Alors que l’importante déformation volumique négative correspondait à la contrainte différentielle ultime avec les faibles contraintes principales intermédiaires, dans les conditions de fortes contraintes intermédiaires, le matériau rocheux subissait l'endommagement de façon beaucoup moins importante. En résultat, la rupture des échantillons rocheux au stade post-maximum était beaucoup plus violente et accompagnée d’un fort effet acoustique. Prismatische Probekörper des mittelkörnigen Sandsteines aus dem Bergwerk ‘Slask’ (das Oberschlesische Kohlengebiet, Polen) wurden unter der einaxialen Druckbeanspruchung, konventionellen dreiaxialen Druckbeanspruchung und der echten dreiaxialen Druckbeanspruchung geprüft. Konventionelle dreiaxiale Druckversuche wurden bei dem Manteldruck von 12,5 25,0 und 37,5 MPa durchgeführt. Bei den echten dreiaxialen Druckversuchen betrug die kleinste Hauptspannung (s3) 25,0 MPa und mittlere Hauptspannung (s2) war 1,5-, 2- und 2,5-mal höher als s3. Aus den durchgeführten Versuchen ergibt sich, dass der Manteldruck die Dilatanzentwicklung bei den Probekörpern unter der konventionellen dreiaxialen Druckbeanspruchung stark bremst; die Erhöhung des Druckes rief die ansteigende Kompaktion des Gesteinsmaterials hervor. Die Dilatanz wurde auch durch die mittlere Hauptspannung beschränkt. Während die wesentlichen volumetrischen, dilatanten Verformungen der Grenzdifferenzspannung bei den niedrigen mittleren Hauptspannungen entsprachen, bei den hohen mittleren Hauptspannungen wurde das Gesteinsmaterial viel weniger beschädigt. Im Ergebnis war der Scherbruch der Gesteinsproben im Post-Peak-Bereich viel heftiger und mit kräftigen akustischen Effekten verbunden.

Jan 1, 2003

By H. H. Schrenk, W. P. Yant, F. A. Patty

"INTRODUCTION In accordance with the outline of investigation described in a previous report 5 of the Bureau of Mines dealing with the use of acrolein for detecting leakage of methyl chloride from unit--type refrigerating systems, the work has been extended to include an investigation of its use in a multiple system, This report gives the results of analysis of samples of the gas from representative units of a multiple system charged with methyl chloride containing approximately 0.9 per cent acrolein by volume, The results furnish a basis for estimating the Warning that would be given in event of leakage. The properties and warning intensity of acrolein have been described in a previous report. 5 ACKNOWLEDGMENTSThis investigation was made at the combined request-of Several Inc., Manufacturers of refrigerating, appliances, and the Roeasler Hasslacher Chemical Co., manufacturers of methyl chloride. Acknowledgment is given to R. M. Major, ,chief chemist of the former firm for arranging the experimental site and equipment; to Arthur O. Haseeneall, owner of the apartment building where the investigation was conducted, for his courtesy in permitting the investigation; and to R. R. Sayers, chief surgeon, Bureau of Mines, and surgeon., U. S. Public Health Service, for suggestions and advice."

Sep 1, 1930

By Anderson Pereira

SORM 3plus (SORM = Superfast Optical Roughness Measurement) is a system enabling online measurement of roughness parameters during continuous strip processing. Increased requirements for new materials and more complex components call for ever increasing process safety. The roughness parameters are important quality features of uncoated and surface refined strips. The traditional method of measurement involves using a mechanical stylus based instrument. For this purpose the operator must stop the production line or samples are taken from the end of the coil and measurements are made offline in the lab. SORM 3plus, however, is a non-contact, online surface roughness measurement system that can be used for metallic and many non-metallic surfaces at strip speeds of up to 2400 m/min. The surface roughness data are stored in the system computer, displayed to the operator and if needed are fed into a higher-level network. The operator is alerted, if the limited values preset by him are exceeded or if any changes within the line will put at risk the production process. SORM 3plus calculates the roughness parameters as defined in the standards, such as the arithmetic average roughness (Ra) and the peak count (RPc).

Oct 8, 2019

By Wolfgang G. Brunner

The closing of the gap in the European waterway- net is one of the big and challenging traffic projects following the German reunification. The water canals in the North German plain connect the Rhine river, the border between Germany and France, with the Oder, the German border river to Poland. As early as in the 30's of the 19th century the planning and construction of a ship- lift and a canal bridge started, in order to close this last big gap in the system between the Mittelland Canal and the Elbe- Havel Canal near Magdeburg. This main waterway connects the West of Germany, known for its coal mines and steel mills, with the capital Berlin, and from there it goes on into Poland. The building activities started in 1934 but came to a complete stop in 1942 because of the war. The communist government in East Germany was not interested in continuing this huge project, including the ship lock Rothensee, the canal bridge crossing the river Elbe, the former border river between West and East Germany, and the lock Hohenwarthe due to lack of political backing along with low construction capacity. Now this important project is in progress and this report describes the special foundation techniques used on the great ship lock Hohenwarthe. Hohenwarthe is a double- bay ship lock of considerable scale, which is notable for recirculating water rather than letting it flow. It includes 44 800 m2 ( 481 720 sq. ft) of up to 55 m ( 180 ft) deep cut- off walls, ground water control, 1248 bored piles with a depth of 22 m ( 72 ft ) serving as foundation and 28 000 m ( 91 864 ft) of soil densification with vibroflotation equipment for ground improvement. In the year 2003 the project shall be completed and all ships can travel from the West to the East through Germany without expensive and time- consuming detours through other canals and locks.

Jan 1, 2000

By Walter L. Fisher

The public interest in the Alaskan situation is such that, with the consent of the President, I have concluded, at the request of the American Mining Congress, to make at this time a candid, if somewhat informal, expression of the views I have formed as Secretary of the Interior, under whose official supervision much of the administration of the Territory is now placed. Pressure of other matters imperatively requiring attention has prevented their presentation in as precise and comprehensive a form as I had hoped. The absence of the President from Washington has also prevented the submission to him of what I have prepared. I wish to say, however, that no one is more earnest than he in the desire to see a policy of prompt and wise development inaugurated in Alaska, and that the general policy contained in this address has been discussed with him, meets his approval, and will have his support. I have recently returned from an altogether too brief but nevertheless a most interesting and profitable visit to those portions of Alaska that are more immediately involved in the questions now under public consideration. Favored by extraordinary weather and the cooperation of steamship and railroad lines and the assistance of all of the governmental agencies, including the Revenue-Cutter Service, I visited every port in Alaska that seems likely in the near future to become an important entrance to the country. I examined all of the harbor and town sites which for this purpose have attracted any considerable public attention. I traversed the entire length of each of the three railroads that have been constructed in the Terri.tory and made a short trip from White Horse down the upper Yukon. Both before and during the journey I examined a mass of books, records,' and papers relating to the country and its resources. I had conferences with official committees representing the principal communities I visited and with numerous individuals, residents both of the coast and of the interi.or, and conferred with engineers, miners, prospectors, railroad officials, business and professional men.

Jan 1, 1911

By Dennis Ofiara

Several recent tunnel jobs have required special adaptations of hard rock TBMs. Some of the special job conditions are ?no blast? launch requirements, small shafts or launch pits, proximity to existing underground structures, and short tunnels where the TBM must be retrieved through the primary lining. This paper describes a few of these projects, and the machine adaptations that have made TBM excavation feasible.

Jan 1, 2008

By A J. Eggers

With gold first discovered at Carrick in 1864, exploration and mining on the Carrick Goldfield in Central Otago, New Zealand, has now been ongoing for more than 130 years. Recorded historical hard rock production from up to 52 different mining claims from 1864 to about 1921 is 24,047 ounces (oz) of gold.   Since 1980 Amoco Minerals New Zealand Limited, CRA Exploration Pty. Limited, Amax Gold Mines New Zealand Limited and Summit Gold (New Zealand) Limited have conducted modem systematic exploration campaigns targeted at locating shear controlled gold bearing quartz lodes and stockwork deposits. More than NZ $1million has been spent by these companies on aerial photography, geological mapping, stream sediment surveys, soil and rock chip geochemistry as well as reverse circulation (RC) percussion and diamond drilling.   RC drilling by Summit Resources in 1997 has identified a 1,500 m long zone of low-grade gold mineralisation at Lower Carrick, with an average grade of 1.00 g/t Au over a 14 m average thickness. This gold mineralisation, hosted within a low angle shear zone, has analogies with the Hyde-Macraes Shear Zone in eastern Otago. Recent exploration and drilling at Carrick has revealed the potential to discover large (>0.5 million ounce (Moz)) low-grade bulk shear controlled quartz vein and stockwork gold deposits similar to those now being mined at Macraes.

Jan 1, 1997

By P. Tolvanen, A. Jalili

"When hard times strike in the mining cycle, sites tighten their belts and focus on lowering their unit costs. Lower unit costs can be achieved by reducing expenditure, increasing production, or by a combination of both. Faced with these requirements, site personnel must turn to areas where they can focus their effort for maximum return. For many sites, both in Canada and overseas, focusing on improving flotation cell maintenance is one of the areas where gains can be made for minimum outlay. Due to resource limitations and/or lack of equipment understanding, maintenance on many sites is only conducted on a reactive basis, once equipment fails. This paper will promote the idea that mineral processors should become more familiar with their equipment so they can ensure that the plant’s ability to produce is not compromised. By better understanding the flotation equipment and ensuring the critical components are maintained, it should be possible to unlock value in an operation. Flotation equipment inspections will be discussed in detail, including key items to look for during these inspections. Potential approaches for predicting wear and change-out time for flotation equipment components will be also demonstrated. An example of one approach used at a South African nickel site will be given.INTRODUCTIONWith metal prices decreasing and operating costs rising, concentrator operators are looking for ways to improve their bottom line. Lower unit costs can be achieved by reducing expenditure, increasing production, or by a combination of both. To meet the expectation of shareholders, mineral processors must turn to areas where they can get the best return for their efforts. One area where there is a large opportunity for improvement is in the maintenance of flotation equipment.On many mine sites, both domestically and around the world, it is quite common to see the philosophy applied of repairing equipment only once it has failed. Though some sites have advanced enterprise management systems and monitoring programs, in the authors’ experience, the decision on flotation equipment maintenance is rarely made on a proactive basis. Two common trends that are evident in the mining industry are that operations are under pressure to keep the plant producing, and maintenance managers generally have very strict budget targets to meet. In addition to these factors, few sites have a good understanding of the financial implications of running with worn or broken flotation equipment. Knights, Jullian and Jofre (2006) summarize this situation well, stating that the lack of correlation between some commonly used maintenance performance measures and key business drivers can lead to maintenance being seen only as a cost center (that needs to be reduced) rather than a tool for productivity improvement."

Jan 1, 2015

By H W. Wu

The objective of this paper is to examine some modern forms of auxiliary ventilation fabric ducting with streamline design fittings and the efficiency of construction practices. The most dynamic form of auxiliary ventilation is a moveable fan and ducting, which is easy to install and uses light weight fabric. The porous nature of some ducting construction results in leakage and loss of efficiency. Flexible fabric ducting is primarily associated with metalliferous mining and industrial material quarrying. Some applications are found in coal in stone/rock development and with use of dust scrubbers.Forcing auxiliary ventilation systems employing circular fabric ducting have been examined. Leakage of air from ducting is affected by ducting material and construction methodology (such as welded or sewn), quality of installation, number of joints, total length, pressure differences between the inside and outside and diameter. The best ducting system with welded construction can have up to four times less leakage as compared with some systems with sewn construction. It is also evident that the sewn type ducting will deliver less air to working faces and require more fan power, hence higher operating costs to run when connected to the same fan.A case study has also been undertaken to compare predicted operating costs of auxiliary ventilation systems connecting various types of ventilation duct fittings. The study also assesses the technical importance of streamline design with low aerodynamic resistance to reduce the shock losses of the duct fittings. It was found that the system connected with streamline designed fittings is able to provide some power cost savings and deliver more air compared with the system fitted with conventional fitting pieces.Using a ventilation ducting system with a lower leakage and frictional characteristic represents a sound solution to new challenges faced by the industry for increasing demand for better quantities and quality of air delivered to working faces; this is due to higher production schedules and stricter mine health and safety regulations within the Australian mining industry.CITATION:Wu, H W and Gillies, A D S, 2017. A comparison of auxiliary ventilation systems and their predicted operational performances, in Proceedings Australian Mine Vent Conference 2017, pp 207–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Gábor Csicsovszki

We have developed a novel method - at the laboratory scale - comprising an ion-exchange separation and a membrane-electrolysis step for the purpose of zero-waste regeneration of spent HCl pickling liquors originating from hot-dip galvanizing of common steels. It is aimed at the parallel regeneration of HCl and iron. Experiments revealed that iron can be electrodeposited at high current efficiencies by maintaining the following conditions: 0.04-0.08 M HCl, 500-1000 A/m2, 20°C and stationary electrolyte in a conventional cell. Zinc in the solution did not disturb the deposition of iron, however it contaminated the product and it poisons the anion-exchange membrane required to tackle acidity during electrolysis. For a preliminary separation, anion-exchange tests were carried out to produce pure iron solutions. Beyond the equilibrium studies, column experiments were carried out showing that low flow rates of the loading solution and the ~1.5 M HCl eluent are essential for separation.

Jan 1, 2006

By I Thin, L Morizzi, C Seymour, G Mungur

Olympic Dam has been investigating mine design options for the South Mine Area (SMA), which will continue using the existing sublevel open stoping (SLOS) method. The SMA is an undeveloped mining area, located south of the existing underground mining areas currently in production at Olympic Dam. The SMA study reached the stage where geotechnical inputs were required for stope design, infrastructure location and ground support forecasts. A large database of geotechnical data was collected to inform open pit designs for the ODX (Olympic Dam expansion) project (resulting from 659 drill holes). This geotechnical data has since been reprocessed to align with design inputs required for the SLOS mining method. The result has been the construction of a preliminary three-dimensional mining rock mass model (MRMM) that has been incorporated into preliminary stope mine design and infrastructure layout assessments, which have taken into account the predicted prevailing ground conditions.As with any model, it is necessary to improve the confidence in its predictability; therefore the model must be calibrated. The preliminary SMA MRMM was no exception. First pass calibration was possible with results from underground geotechnical window mapping from exposed rock mass conditions in the lateral development and surface geotechnical holes for ventilation shafts.The SMA project continues to advance and has started a program of resource drilling. Selected holes have been identified that target data limited areas. This will ensure that the data gaps are infilled in order to maintain the required data density required to improve the model confidence. In addition, further underground window mapping in the SMA will provide ‘mine scale drill hole’ data that can be used to either update the MRMM or as part of planned future calibration. Stope performance data from stopes will provide further valuable data for calibration purposes.The proposed paper will present the process and findings that have been followed in order to establish a well calibrated geotechnical model that can be used with an acceptable level of confidence in the ongoing refinements of the mine design and planning process for the SMA.CITATION:Thin, I, Morizzi, L, Mungur, G and Seymour, C, 2016. Building and calibration of a geotechnical model for sublevel open stope design at Olympic Dam, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 523–532 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Robert G. Harris

During the last five years there have been significant improvements in face support monitoring techniques particularly in respect of face pressure. The measurement of support loading pressures was originally conceived as a maintenance aid for the hydraulic systems but recent work has also included geological loading displays of the complete face as well as individual supports. This paper briefly examines the means of obtaining this information, together with some examples of actual face data. Also included is a summary of the benefits of such monitoring and an outline of future development work.

Jan 1, 1993