Search Documents

By M. Ghoreychi, X. Daupley

ABSTRACT: The paper is devoted to two major aspects related to the abandonment of salt mines: 1)- Long-term risk associated with the mechanical instability of surface and its consequences for public security and properties. 2)- Long term dissolution and transport of salt resulting from its communication with groundwater. Basic characteristic features of salt deposits and mining methods are presented through the studies already undertaken on French mines. This analysis allows to identify major hazards encountered in different traditional salt mines and solution-mining cavities. In particular, the role of overburden (presence and thickness of salt layer in exploitation roof, presence of clayey rocks or hard rocks e.g. dolomite or anhydrite), presence of water-bearing strata and possibly natural brine levels, discontinuities, etc. are discussed. In the second part, the main features of mechanical behaviour of salt (creep, damage) as well as transfer processes of this material are presented. The influence of these aspects on the long term evolution of abandoned salt mines is then analysed. KEY WORDS: exploitation, abandonment, salt, mechanical, stability, transport, solution, brine. ZUSAMMENFASSUNG: Der Artikel bezieht sich auf zwei bedeutende Aspekte beim Salzabbau: 1)-Das langsfristige Risiko zur Bodenoberflächeunbeständigkeit und sein Einfluss über Mensch= und Gütersicherheit. 2)-Die langsfristige Auflösung und Beförderung des Salz beruhen sich auf Studien über französiche Bergbauen. Diese Analyse emöglicht es, die bedeutendesten Risiken in verschiedenen Salzgruben zu identifizieren, bzw. Traditionellen oder durch Auflösung abgebauten. Insbesondere wird die Rolle des Deckgebirges (Vorhandensein und Dicke von Salzschicht am Dach des Grube, Beisein von Tanlager oder hartem Gestein wie Bitterkalk oder Anhydrid), Beisein von wasserhaltigem Boden und/oder gesalzenen Wasserflächen, Trennflächen, usw… erötert. Im zweiten Teil werden die haupsächlichen Eigenschaften des Salzverhaltens (Kriechen und Beschädigung) beschrieben. Ihr Einfluss über das Verhalten von stillgelegten Bergwerken lässt sich analysieren. SCHLÜSSELWÖRTER: Bergwerksbetrieb, Stilllegung, Mechanik, Beständigkeit, Ausbreitung, Aussolung, Solewasser. RESUME: L’article est consacré à deux aspects majeurs liés à l’abandon d’exploitations de sel : 1)- Le risque d’une instabilité à long terme de la surface du sol et son incidence sur la sécurité des personnes et des biens. 2)- La dissolution à long terme et le transport de sel sous l’effet d’une communication avec des eaux souterraines. Les principales caractéristiques de gisements et d’exploitations de sel sont présentées en s’appuyant sur les études antérieures réalisées sur les exploitations en France. Cette analyse permet d’identifier les risques majeurs rencontrés dans différentes mines de sel traditionnelles ou exploitées par dissolution. En particulier, le rôle du recouvrement (présence et épaisseur d’un banc de sel au toit de l’exploitation, présence de terrains argileux ou de roches dures telles que la dolomie ou de l’anhydrite), présence de terrains aquifères ou de nappes salées éventuelles, discontinuités, etc. sont discutées. Dans la deuxième partie, les principaux traits du comportement mécanique du sel (fluage, endommagement) ainsi que les processus de transport de ce matériau sont présentés. L’influence de ces aspects sur le comportement à long terme d’exploitations abandonnées de sel est ensuite analysée. MOTS CLES: exploitation, abandon, mécanique, sel, stabilité, transport, dissolution, saumure.

Jan 1, 2003

By Delahant A. B, Dworski M

From the Saranac Laboratory for the Study of Tuberculosis of the Edward L., Trudeau Foundation, Saranac Lake, New York:We are assembled to honor the memory of our friend and colleague, Donald Cummings, one of the founders and a past president of the American Industrial Hygiene Association. I deem it an Unusual privilege to have been asked to give this first memorial lecture and hope that what shall have to say may be worthy of the occasion. It is fitting that we should discuss here the subject of Silicosis to which he devoted such a large part of his life and it is doubly fitting, I think, that I should report to you an extended series of investigations carried on by his associates at the Saranac Laboratory.The subject of silicosis may seem hackneyed to this audience which is so familiar with the tried and accepted methods of prevention and control.But in spite of our efforts, the condition is still with us and unfortunately is still being produced in many places. In industries that now maintain good control of dust, fresh cases are appearing on annual re-examination, whose major exposure date back to the days before the hazard was recognized.A few new employees, with apparently ineffective upper respiratory protection against inhaled dust, develop silicosis precociously in environments that are comparatively harmless to their fellows. In plants that have relaxed their vigilance under the urgency of war production schedules, conditions again prevail that will produce, disease in the future.Silicosis acquired new interest with the announcement by Denny, Robson and Irwin(1) in 1937 that it could be prevented by the inhalation of powdered metallic aluminium. It so happened that without knowledge of their work, we at the Saranac Laboratory had for some months been conducting similar experiments with one of the hydroxides of aluminium.Quite independently we discovered that hydrated alumina would also protect animals against quartz. Our approach to the problem had been empirical; we were trying to neutralize quartz particles by coating their surfaces with an insoluble material following the lead of Kettle who in 1932 had shown that this could be accomplished with iron. He neglected to describe his method and the chemist who prepared his coated...

Jan 1, 1945

By John R. Hoskins

The Bureau of Mines conducted an investigation to more exactly define the influence of some end conditions on the laboratory-determined uniaxial compressive strength of rock samples. Limestone, marble, sandstone, and granite were used to provide a range of specimen modulus of elasticity from 2.7 X 106 psi to 10 x 106 psi. Four variables were studied: Nonparallelism and surface texture of specimen ends were the specimen variables investigated; the end platen size and the adjustable or spherical head friction were the machine variables studied. It was concluded that the loading ends of small laboratory models and samples should be prepared with surface irregularities that do not vary from a plane surface by more than 0.001 inch. It was also concluded that nonparallelism of the specimen ends should not exceed 8 minutes for a rigid head load or 15 minutes for an adjusting head load. The measured compressive strength of specimens prepared with these tolerances will be statistically the same with any diameter or thickness of platen and any degree of head friction if initial alinement of the specimen is assured.

Jan 1, 1968

Delivered at the University of Sydney, on June 4th, 1954.THE TORCH WE HOLDLast year Our Institute celebrated its Diamond Jubilee, coincident with the holding of the Fifth Empire Mining and Metallurigcal Congress in Australia and New Zealand. We can be proud of our growth over the 61 years since the inaugural meeting in Adelaide in April, 1893, which followed suggestions from a provisional committee of mining men, formed in 1892 in Broken Hill.We can also be proud of our technical achievements in the fields of economic geology, mining and metallurgy.Should we be content with the growth of our mining and metallurgical industries over these years? My answer is in the negative. The discovery of new mineral deposits is essential for the continuance and development of the industries we represent.Let me review the background and trends of our industry in an attempt to emphasise the changing factors influencing the search for minerals and their exploitation.Australia was blessed with the discovery of coal in New South Wales in 1796; copper in South Australia at Kapunda, Burra, Wallaroo and Moonta in the eighteen-forties; gold in Victoria and Eastern Australia in the 'fifties; tin at Mount Bischoff, Tasmania, and gold at Charters Towers, Queensland, in the 'seventies; lead-silver at Broken Hill, New South Wales; gold and copper at Mount Morgan, Queensland, and copper at Mount Lyell, Tasmania, in the 'eighties; and gold at Kalgoorlie, Western Australia, and zinc-lead atRosebery, Tasmania, in the 'nineties. As well, the iron ore deposits of the Middleback Ranges, South Australia, and Yampi Sound, Western Australia, were known before...

Jan 1, 1954

By Fulvio Tonon

And Rabcewicz said ?tunnels should be driven full face whenever possible.? ADECO, which stands for ?Analysis of Controlled Deformations in tunnels,? now allows us to fulfll Rabcewicz?s dream in any stress-strain condition. In order to achieve that dream and its consequent control over cost and schedule, however, NATM must be abandoned for the ADECO. The paper presents the basic concepts in the ADECO approach to design, construction and monitoring of tunnels together with some case histories, including: full face excavation for Cassia tunnel (width of 22 m, height of 14 m) in sands and silts under 5 m cover below an archeological area in Rome, Italy; Tartaguille tunnel (face area > 100 m2) advanced full face in highly swelling and squeezing ground under 100 m cover where NATM led to catastrophic failure, France; and 80 km of tunnels (face area > 100 m2) advanced full face in highly squeezing/swelling ground under 500 m cover for the high-speed railway line between Bologne and Florence, Italy (turnkey contract).

By C. C. Harris, A. Jowett, S. K. Ghosh

An equation derived from first-order kinetics and accounting for return from froth to pulp has correlated continuous flotation data. The concentration of floatable material in the pulp can be altered either by changing the feed concentration or the feed rate. The latter does not affect the flotation rate constant, the froth to pulp return constant, and the concentration of non-floatable material in both the pulp and concentrate. Both the return constant and the concentration of non-floatable material in the pulp are directly proportional to the feed concentration, while the concentration of non-floatable material in the concentrate is related to the feed concentration. The investigation of the froth flotation process by continuous test methods, previously used by Brown and smith,1 Jowett and Safvi2 and Jowett and West,3 is being continued. Recent tests, primarily concerned with flotation cell design, have yielded kinetic data suitable for testing an equation proposed by Arbiter and Harris4 which postulates that a flotation process is defined by two rate constants: 1) the rate constant for mass transfer from pulp to froth. Previous workers have regarded this as the flotation rate constant. 2) the rate constant for mass transfer from froth to pulp, which has previously been ignored. THEORY Under continuous flow conditions at the steady state in Fig. 1 the equation developed4 is Symbols are defined in Table I. The air-liquid ratio terms4 have been omitted, since they are substantially constant for a given set of conditions. Also, for a system operating at the steady state Vf and V, remain constant and Eq. 1 can be written: Cp/Cc=b'/a,+Qc/a' [2]

Jan 1, 1963

By J. Searra, M. Aboagye

"For new mining projects or for medium- to long-term areas of existing mines, drilling data is invariably on a relatively large grid. Direct estimates for selective mining units (SMUs), and also for much larger block units, will then be smoothed due to the information effects and the high error variance.The difficulty is that ultimately, during mining, selection will be done on the basis of SMUs on the final close-spaced data grid (grade control), which will then be available, i.e. the actual selection will be more efficient, with fewer misclassifications. However, this ultimate mining position is unknown at the project feasibility stage and therefore has to be estimated. This estimation is required because any cash flow calculations made on the basis of the smoothed estimates will obviously misrepresent the overall economic value of the project, i.e. the average grade of blocks above cut-off will be underestimated and the tonnage overestimated for cut-off grades below the average grade of the orebody. Similarly, unsmoothed estimates will be conditionally biased and will give even worse results, particularly in local areas of short- and medium-term planning or mining.This paper presents a case study of indirect post-processing and proportional modelling of recoverable resources designed for mediumand long-term mine planning at the Gold Fields’ Tarkwa Mine in Ghana. The case study compares long-term indirect recoverable mineral resource estimates based on typical widely spaced feasibility data to the corresponding production grade control model as well as the mine production. The paper also proposes certain critical regression slope and kriging efficiency control limits to avoid inefficient medium- to longterm recoverable estimates, and highlights the danger of accepting block estimates that have a slope of regression less than 0.5."

Jan 1, 2015

By F. Ajersch, M. Rigaud, M. Jallouli

"Le gonflement des boulettes d'hématite à été étudié à l'aide d'une méthode de mesure standard ISO ainsi qu'à l'aide d 'une méthode de mesure dilatométrique.La première méthode a servi à l'étude des boulettes haute silice (5% SiO2) dont l'indice de basicité (IB = CaO + MgO -i- SiO2 + Al2O3) a été ajustée soit à l'aide d'une addition de dolomie, soit à l'aide d'une addition de pierre à chaux, soit à l'aide d'une addition de ces deux composes. L'indice de basicité variait de 0.05 à 0.12. Les résultats de gonfle ment obtenus à 1000?C dans une atmosphère de 40 CO - 60 N2 ont permis de montrer qu’indépendamment de l'indice de basicité c'est la dolomie qui contribue le plus à diminuer le gonflement par rapport à la pierre à chaux. L'utilisation de l'indice de basicité comme critère de sélection des boulettes est discutée.La méthode dilatométrique a servi à l'étude du gonfle ment de deux types de boulettes préparées à partir de deux concentrés de fer et dont la teneur en silice a été fixée à 2.5% et 0 5%. Ces deux types de boulettes ont reçues les mêmes additions de liant en quantité et en nature. La détermination en continue du gonflement, à 950?C dans 40 CO - 60 N2, a permis d'une part de mieux cerner le niveau de réduction auquel correspond le maximum de gonflement et d'autre part de montrer que l’allure des courbes de gonflement est étroitement liée à la nature du liant. Une augmentation de la teneur en silice des concentres contribue à diminuer le gonflement des boulettes.Des essais de réduction de gonflement non isothermes ont été réalisés à des montées de température à 10 et 20?C/min. Les résultats indiquent que le gonflement déterminé dans les conditions non iso thermes est inferieur à celui obtenu lors des essais isothermes. On discute alors de la validité des essais standards de gonflement qui sont utilisés pour prédire le comportement des boulettes lors de leur réduction dans un haut fourneau."

Jan 1, 1983

The U.S. Bureau of Mines, Department of Labor, and United States National Committee of the CIE hosted the TC4.10 Mine Lighting Committee Meeting and Second International CIE Mine Lighting conference at the MSHA Academy in Beckley, WV from October 12-16, 1981. This was the first time the meeting and conference had been held in the United States. The TC4.10 Mine Lighting Committee, chaired by Dr. Adam Peretiatkowicz of Poland, was attended by 15 committee members and six guests representing eight countries. Discussion during the meeting covered mine lighting instrumentation, open cast (surface mine) lighting, and lighting sources. The committee also reviewed a draft of proposed lighting terminology and suggested changes to make the definitions more acceptable to representatives of the nations present. The mine-lighting conference featured 20 papers presented by 18 speakers representing six countries. The papers covered all phases of mine lighting, including research, hardware development and application, personnel acceptance, and requirements for system maintenance. The conference attracted 126 attendees and also included displays by eight lighting hardware manufacturers and four mining machine manufacturers. Papers from the conference are being published by the Government Printing office, with copies presented to the conference attendees. Copies will be available to others interested through the NTIS. During the course of the TC4.10 meetings and conference, committee members toured three mining equipment assembly plants, and six of the foreign representatives visited a longwall installation in an underground mine. Planning and administrative services for the meeting and conference were handled by Bituminous Coal Research, Inc., under USBM Contract H0318038.

Jan 1, 1982

It is estimated that the tailings dam of the Mouteh Gold Mine, in Iran, contains more than 770 kg of gold. Microscopic analysis reveals that sulphide minerals and active carbon are the main sources of the gold in the tailings residue. Flotation and cyanidation tests on the samples of tailings were conducted. Flotation concentrates, containing around 87.79% of the gold, which were associated with sulphide minerals, were recovered. By regrinding, roasting, and cyanidation of the flotation concentrate, the gold dissolution recovery was in the range of 87.8 to 98.4%. The carbon-in-column method was used to recover 98% of the gold from the solution. Keywords: gold ore, pyrite, flotation, roasting, cyanidation

Jan 1, 2009

By J. M. McKinley

Mineral exploration programmes around the world use data from remote sensing, geophysics, and direct sampling. On a regional scale, the combination of airborne geophysics and ground-based geochemical sampling can aid geological mapping and mineral exploration. Since airborne geophysical and traditional soil-sampling data are generated at different spatial resolutions, they are not immediately comparable due to their different sampling density. Several geostatistical techniques, including indicator cokriging and collocated cokriging, can be used to integrate different types of data into a geostatistical model. However, with increasing numbers of variables the inference of the crosscovariance model required for cokriging can be demanding in terms of effort and computational time. In this paper a Gaussian-based Bayesian updating approach is applied to integrate airborne radiometric data and ground-sampled geochemical soil data to maximize information generated from the soil survey, enabling more accurate geological interpretation for the exploration and development of natural resources. The Bayesian updating technique decomposes the collocated estimate into two models: prior and likelihood models. The prior model is built from primary information and the likelihood model is built from secondary information. The prior model is then updated with the likelihood model to build the final model. The approach allows multiple secondary variables to be simultaneously integrated into the mapping of the primary variable. The Bayesian updating approach is demonstrated using a case study from Northern Ireland. The geostatistical technique was used to improve the resolution of soil geochemistry, at a density of one sample per 2 km2, by integrating more closely measured airborne geophysical data from the GSNI Tellus Survey, measured over a footprint of 65 x 200 m. The directly measured geochemistry data were considered as primary data and the airborne radiometric data were used as secondary data. The approach produced more detailed updated maps and in particular enhanced information on the mapped distributions of zinc, copper, and lead. The enhanced delineation of an elongated northwest/southeast trending zone in the updated maps strengthened the potential for discovering stratabound base metal deposits..

Jan 1, 2014

By M. Bwalya, L. Mabokela, L. C. Woollacott

This paper presents a study on the ability of the King stratification modelto describe density stratification patterns that are achieved under idealizedconditions. Tests were conducted in a batch jig using artificial particles inseven density classes. All particles in a density class had essentially thesame density, size, and shape. Tests were conducted for particle systemsinvolving from two to seven components. Good agreement was obtainedbetween measured and modelled data to an extent that gave strongendorsement of the mathematical appropriateness of the core equation inthe King model. Somewhat ambiguous results were found with regard toclaims about the independencies of the single experimentally-determinedparameter required by the model.

Jan 1, 2015

By Frank van der Meer, Jorge Portocarrero, Alexandra Gruendken

"The number of High Pressure Grinding Rolls (“HPGRs”, also called Roller Press) installations instead of tertiary crushers is rapidly increasing. The technology has been largely accepted in the minerals industry and benefits, such as superior energy efficiency and a lower overall operating cost compared to alternative technologies, have been demonstrated at a number of operations throughout the world.This paper focuses on coarse hard ore operations and reviews the successful installation of the first Roller Press installed instead of a tertiary crusher at the Los Colorados Plant of CMH (Chile) in 1998. It details the experience obtained over the past ten years of operation from commissioning to the present day. It highlights examples of further developments made in the design to improve machine maintainability and availability as well as wear life of the grinding surfaces.A second focus lies on procedures to derive from small scale testing material properties such as wear life, flake formation and strength and their application to industrial size machines to optimize circuit design, especially when Roller Presses are used in closed circuit with screening.INTRODUCTIONRoller Presses (also known as HPGR, High Pressure Grinding Rolls) are considered today state of the art for the preparation of pellet feed. They are also gaining wide acceptance in coarse ore operations. One of the first successful operations in which a roller press was used to replace a conventional tertiary and quaternary crusher is the Los Colorados plant of CMH in Chile.When the Roller Press at Los Colorados was commissioned in 1988, there were 169 Humboldt Wedag roller presses in operation throughout the world. Of these, 14 were installed in the minerals industry. However, these were installed mainly for grinding pellet feed to increase the Blaine value. Up to that time, only three KHD roller presses had been applied for crushing coarse ore in specialized circuits. Moreover, the installation at Los Colorados was the first Roller Press ever to replace a conventional tertiary and quaternary crusher in a hard ore application."

Jan 1, 2009

Results obtained from small scale tests using Australian tin concentrates indicate that metallic tin containing less than 0·1 per cent iron can be recovered by a two-stage process using hydrogen and make-up chlorine. In the first stage the concentrate is ground,. pelletized, roasted, and reacted at 650°C with HCI and H2 to volatilize the tin as SnOI2. The volatilization reaction is conducted with cocurrent gas and solids flow because it was found that the use of cocurrent flow yielded a solids residue substantially free from FeCI2. The second stage uses a technique termed "reflux reduction" during which the SnOl2 produced by volatilization is reduced by hydrogen to form tin and a gas containing HCI and H2 of sufficiently high HCI tenor for recycle to the volatilization stage. The elimination of tin ranged from 98+ to 99·7+ per cent of the tin from concentrates containing 5 to 50 per cent tin, respectively. The process should be capable of continuous operation, and a tentative calculation has shown ,that a treatment rate of 12,000 tonnes of tin concentrate per year could be obtained in a volatilization reactor 1·1 m in diameter and 6·1 m high. The process may have particular application to finely divided concentrates containing less than 20 per cent tin.

Jan 1, 1974

By H. B. Pulsifer

ONE of the most common basic open-hearth furnace products is a simple carbon steel with a carbon range from 0.05 to 0.15 per cent. The material is widely used for sheets, tubes, bars, wire and the innumerable special objects of secondary fabrication. The properties of the material vary over wide ranges, depending on the more exact composition and details of manufacture or treatment that affect its structure. The present paper is a review of those properties and structures that have been found by studying this steel as used in the cap screw industry. At first glance this might be thought a narrow application of the steel, but, since the industry uses the material in the cold-worked, annealed and heat-treated conditions, the title of the paper may be excused for its comprehensiveness. Yet, in studying the wide ranges of properties and structures that preclude a more specific title, there can be no suggestion of completeness or finality. Even a summary of a few years' work is no more than a preliminary survey of a field that will be fertile in scientific data and industrial products for many years to come. An outline of the structures will be given first, then a list of the previous contributions that are at hand and finally some details of the work and related problems, especially concerning this low-carbon steel in the surface-hardened condition.

Jan 1, 1931

By G. X. Wang, R. E. Siemens, M. C. Fuerstenau, D. Chandra

Soda roasting of concentrates from Mouat, Montana, was performed in a temperature range of 450 to 650 degrees C and chromium was solubilised by water leaching at room temperature. It was found that high extraction yields of chromium were primarily dependent on the conversion of Cr3+ to Cr6+ during the roasting step, and this was enhanced significantly by simple attrition of chromite particles during this step. Gangue impurities (mainly Si) were more detrimental to Cr extraction than lattice impurities such as Al or Mg. It appears that oxidation proceeds into grains along a preferred crystallographic plane in the cubic lattice of the chromite. The effects of roasting time, temperature, soda to chromite ratio and particle size on the extraction of chromium are presented

Jun 18, 1905

One of the chief drawbacks to Bendigo mining always has been the difficulty of draining the mines in an equitable manner, so that each company or mine owner bears the properly share. The trouble seems to have been apparent on this field since the diggings were discovered. One mine would push on more expeditiously than its neighbour in looking for the precious metal and sink its shaft, whilst those in the vicinity would simply potter about, and discontinue sinking until gold was struck in the deeper ground, and: then they would go ahead, start sinking, while the pioneer would have to pump all or most of their water. This sort of thing continued here for years until the leases were worked down to the very deep ground and the water became such a b.urden on those companies that had deep shafts, that first one stopped hauiing and then others; with the result that over 1000 feet of water was allowed to accumulate on the New Chum line. lt appeared that if something were not done the whole of the main line of reef in the Bendigo district would be at a standstill, when a scheme was formulated and handed to Mr. Lansell, who, with other gentlemen, took the matter up, and at the present time all the mines on that particular portion of reef are in full work and the water all bailed out.lt is this scheme that I am requested to place before you and also to give you the details of the work done since its adoption.

Jan 1, 1902

By Slavoljub D. Maksimovic

The Bureau of Mines, through a memorandum of agreement with the State of Ohio, tested a method of constructing seals in abandoned mine openings in Ohio by means of pneumatic stowing of crushed limestone and gravel with sand. A total of five openings and one shaft were back-filled. Pneumatic stowing uses compressed air to convey material through a pipeline and into the mine opening. The stowing equipment consists of a power supply, a blower, a feeder to inject the material into the pipeline through an airlock, and a nozzle for directing the placement. Material is ejected from the nozzle at high velocity, creating a high-compaction fill upon impact. Well-graded aggregate up to 2 inches in diameter and having sufficient fines is used as fill. The stowing method is safer and faster than conventional methods, is cost competitive, prevents trespass into abandoned mine openings, and eliminates or reduces the exposure of workers to possible hazards since the discharge nozzle can be kept at the mouth of the opening. The equipment is mobile, and, with some modification, the technique could be widely used for sealing abandoned and active mine openings, even in remote locations and during severe weather conditions.

Jan 1, 1982

By Braam Blom

PK2 Ventilation shaft is part of Paardekraal No 2 twin shaft system that is being developed to replace depleting Merensky reef production at Paardekraal shaft complex. The sinking team at this shaft faced considerable challenge of improving the total sinking cycle in order to be able to deliver the fully equipped shaft on time and on schedule. The cladding support cycle was identified as the tedious and time consuming activity in the overall shaft sinking operation. Reduction in the time required for handling and setting up the support installation equipment, and the time required for subsequent installation of the necessary support has a direct impact on the overall cycle time, and consequently the overall productivity and efficiency of the sinking operation. This reduction in support cycle was achieved by making use of machine carousel. The objective of this paper is to describe the support methodology that was used during the ventilation shaft sinking and the use of the machine carousel to reduce the cladding support cycle. The machine carousel replaces the traditional use of machine kibble in conventional vertical shaft sinking and has been designed specifically for installation of sidewall support at the shaft bottom during the sinking process.

Jan 1, 2009

By V. Koump, T. F. Perzak, R. G. Olsson

Jan 1, 1965