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By H. W. King

"Cryogenic engineering is concerned with components and machines which operate for long periods of time at temperatures within a few degrees of absolute zero. The absence of a ductile-brittle transition is thus the prime component of the specification for a suitable low-temperature alloy. The word "" cryo"" means ""frost-forming"" , and this leads to the second component of the alloy specification, which is resistance to corrosion in humid atmospheres. Further, although most early applications of low-temperature alloys were limited to the storage or transportation of liquified gases, an increasing proportion of alternative energy storage and conversion technologies are being based on the availability of high-field superconducting solenoids. The third basic component of the specification for a low-temperature alloy is thus the absence of a low-temperature ferromagnetic transition.Although the firs t two of these components of the specification can be met by using austenitic stainless steels, many of these supposedly "" non-magnetic"" alloys have been found to undergo martensitic transformations to ferromagnetic phases at very low temperatures. In addition, steels which remain structurally stable may still exhibit other magnetic transitions, e.g. to antiferromagnetic or superparamagnetic states. The successful application of these alloys in cryogenic engineering has thus required an initial basic study of the types of magnetic transition that can occur in such concentrated solid solutions, followed by a more applied study directed at an alloy formulation which will induce beneficial magnetic states at low temperatures."

Jan 1, 1981

By Neil J. Sullivan, Goode. George E.

"The Adams mine, operated by Jones & Laughlin Mining Company, Ltd. and located near Kirkland Lake, Ontario, produces one million tons of iron ore pellets per year. This paper briefly describes the mining and concentrating operation and deals mainly with the operation of the pellet plant. The orebody consists of fine-grained magnetite and some hematite, with alternating layers of chert, and is mined by conventional open-pit methods. After crushing and grinding, the ore is concentrated by magnetic separation and flotation. Agglomeration is accomplished by the grate-kiln pelletizing process. The plant layout and general operation will be discussed in detail."

Jan 1, 1968

By M. Duncan

Lightweight, high-pressure cylinders for compressed hydrogen storage are essential components for fuel cell vehicles. Storage volume and mass are two key considerations. Current on-board hydrogen storage systems are based on a maximum pressure of 350 bar. While 350 bar systems are excellent solutions for many applications, some situations require higher storage densities due to space restrictions. As a result, significant research and development work has been expended by cylinder manufacturers, systems providers, testing agencies and automotive manufacturers to develop 700 bar systems with reduced storage volumes. Dynetek Industries Ltd. has proactively developed several 700 bar storage cylinders based on a seamless aluminum liner over wrapped with a carbon fiber composite. This paper presents the challenges and processes involved in the design, testing and certification for Dynetek Industries Ltd. 700 bar cylinders. This paper also provides reasoning for further volume and mass optimization of compressed hydrogen cylinders through the establishment of realistic cylinder usage parameters in standards. In particular, the overly conservative fill life requirement for cylinders is examined.

Jan 1, 2005

By T. H. Adair

"IntroductionCONTINUOUS casting of ferrous and non-ferrous metals is not a new innovation. Patents describing machines for continuous casting are on file as far back as the year 1842. In the middle of the last century, Sir Henry Bessemer conceived and built a continuous casting• machine for the production of mild steel sheet.The production of billets and slabs of both non-ferrous and ferrous metals is being carried out by the continuous method on a fairly large scale on this continent and abroad. At present, the volume of production of •copper and aluminum and their alloys in billet and slab form is much greater than the continuous casting of steel products. The new installation of a continuous casting unit at Atlas Steels, Limited, is designed primarily for the casting of alloy steel billets and slabs.As an introduction to the art of continuous .casting of metals, it is interesting to examine a few of the many devices which have been developed. As previously mentioned, Sir Henry Bessemer constructed a machine for the direct casting of mild steel sheet. His discoveries and ideas of continuously casting steel formed the foundation for the work of other pioneers in this field, all of whom have contributed to the improvement of this art through the ensuing years. The machines which will be selected for examination are those of Bessemer, Poland-Lindner, Williams, Ennor, and Junghans. The last unit to be discussed will be a modification of the Junghans machine recently installed at Atlas Steels."

Jan 1, 1954

By John Lund

INTRODUCTION GOLD-BEARING placers of Alaska and the Yukon Territories are buried under a layer of permanently frozen alluvial overburden, or 'muck', which varies in depth from twenty to one hundred feet. The placers, and the decomposed bedrock layers upon which they are deposited, are also permanently frozen. During the summer, surface muck which is exposed to the sun will thaw, but only to a depth of a few feet. To reach a valuable deposit, the frozen overburden must be either penetrated with shafts, or stripped from the deposit entirely. In either case, before the placer can be mined, it must be thawed. At modern dredging operations, the frozen muck is stripped from the placer by powerful jets of water from hydraulic giants. The placer, and several feet of decomposed bed-rock, are then thawed by forcing water through narrow pipes which have been driven into the deposit. Other methods of thawing frozen placers were used extensively during the early years of the Klondike 'gold rush', but experimentation later proved that creek water at its natural summer temperature was a more effective and economical thawing medium than any other which had been used. EVOLUTION OF COLD WATER THAWING Early prospectors of the far north reached placers by digging shafts through the frozen muck. They then thawed the placer sand and gravel by building wood fires at the bottom of the shafts.

Jan 1, 1951

By P. J. Oakley, W. M. Thomas, S. W. Kallee, D. G. Staines

A Friction stir welding (FSW) is now extensively used in aluminium industries for joining and material processing applications. The (FSW) technology has gained increasing interest and importance since its invention at TWI almost 15 years ago. The basic principle, recent applications and the continuing development of the FSW technology are described. The paper will introduce some of the variants of FSW, such as Dual-rotation, Twin-stir(TM), and the Stir-lock(TM) technique.

Jan 1, 2006

By J-P. Rossetti, A. Guerin, M. Jaboyedoff, L. Baillet, A. Mariscal, J. D'Amato, D. Hantz

"The processes leading to the fall of rock compartments from rock walls are poorly known as well as their velocity. It ensues that quantitative prediction of the failure time for a rock compartment which is presently stable, is not possible by a purely geomechanical approach. However a quantitative probabilistic prediction of rockfalls at the scale of a rock wall is possible if the spatial-temporal rockfall frequency can be determined or estimated (Hantz, 2011). For a better knowledge of failure processes and frequency, rockfalls have been detected in several rock walls, using annual terrestrial laser scanning, allowing comparison of the frequencies in different geological conditions. For one of these rock walls, the spatial detection have been completed by a precise dating of the events, using a quasi-continuous photographic survey (one photo every 10 mn), allowing the study of the influence of meteorological factors.The precise dating of rockfalls has been carried out for the Saint-Eynard cliff which towers above a residential area of the town of Grenoble (French Alps). The South-East facing cliff consists in bedded limestone gently dipping North-West and located at an elevation between 850 m and 1100 m. The surveyed zone is about 750 m large and 250 m high. Between 01/02/2013 and 26/11/2013, 65 rockfalls ranging between 0.01 m3 and 20 m3, have been detected by diachronic comparison of laser scanner data and dated by comparison of photographic images. The temperature at the elevation of the cliff has been calculated from the temperature measured (every 5 mn) at a meteorological station located at an elevation of 245 m and 2.5 km away from the cliff, using a temperature gradient of 0.003°C/m (D’Amato et al., 2014). The precipitation were measured 900 m away from the cliff at an elevation of 469 m. Different meteorological conditions have been defined: (a) “freeze” qualifies days with negative mean temperature (but with a thaw period, except for two days); (b) “thaw” qualifies days with positive mean temperature, but following a freeze day; (c) “rain” qualifies days with precipitation.Table 1 shows the rockfall temporal frequency for the different meteorological conditions. It appears that the frequency is about 6 times higher the freeze days, 2.5 higher the thaw days and 3 times higher the rain days than days without freeze, thaw or rain."

Jan 1, 2015

By J. Pontt

Gearless mill drives (GMD) offer high performance for torque and speed control for grinding mills and have been applied successfully in modern concentrators for wet grinding with mill diameters from 34 to 40-feet. It is considered a mature technology. However, recently, some large GMD?s have presented unexpected failures in stator and rotor subsystems. The phenomena involved in such failures has shown a complex nature and surprised users and manufacturers. The manifestation of such failures has been observed as mechanical damages to certain components of ring motors. This paper presents a discussion on the electromagnetic forces that can generate stresses in the electrical ring motor that can produce failures and outages. Guidelines for further research and contributions to improved reliability of GMD?s are proposed.

Jan 1, 2012

By C. Turek, R. Henderson

Mine planning is the foundation of value for a mining company. Good mine planning requires solid understanding of the ore body, rigorous standards and processes, robust and useful information technology and skilled people. Life of mine planning is key to identifying strategic direction for any mine and short range mine planning is key to delivering forecast and budget expectations. Mine planning at Kinross has been identified as a critical success factor and initiatives are being prepared to improve the quality of our plans and to build bench strength in our teams. The Kinross Way for Mine Planning (KWMP) has been developed and implemented to establish the standards to ensure a strong business foundation. This paper briefly describes the process used to develop the KWMP and presents a selection of mine planning best practice initiatives at Kinross mines.

Jan 1, 2011

By Z. D. Hora

The major fluorite producer in British Columbia was the Rock Candy Mine, inactive since 1942. Other deposits of economic interest include the Rexspar deposit, in which fluorite is associated with uranium and rare earth mineralization, and the Eaglet and Liard River occurrences. THE former Rock Candy fluorite mine, located 26 km north of Grand Forks, is the only major past producer of fluorite in British Columbia. The deposit was in production from 1918 to 1929 and again in 1942; total output was about 36,000 tonnes with average grade between 22 and 32 per cent CaF2. The fluorite body occupies a steeply-dipping vein structure, approximately 175 m long and up to 12 m wide, in porphyritic syenite. The chief vein-filling minerals are quartz and fluorite with local small len ses of barite. Fluorite content decreases with depth and the deposit becomes silicified. The Rexspar (or Birch Island) fluorite deposit is located 130 km north of Kamloops. The deposit is complex with rare earth elements and high uranium values, but !1uorite mineralization forms an independent zone adjacent to the uranium orebodies. Fluorite is present as fine-grained impregnations and as breccia cement in strongly schistose or brecciated alkali feld spar porphyry. Reported reserves are 1,088,000 tonnes of 22 per cent CaF2 or 450,000 tonnes of 29 per cent CaF2. 268 Another potential deposit of fluorite is Eaglet, situated on the north side of Quesnel Lake. Fluorite occurs as a stock work with scattered veins and irregular lenses up to 20 centimetres wide and as impregnations in altered Proterozoic Kaza Group feld spathic gneiss over an area of 1,500 metres by 500 metres. To date (1983) approximately $2 million have been spent on the exploration of this property and reserves of 18.8 mimon tonnes grading 11.59 per cent CaF2 have been outlined . A group of significant occurrences is known from north of Liard River Hot Springs Park , where fluorite occurs in small zones up to 17 m thick along the interface between Middle Devonian Dunedin Formation limestone and Middle Devonian to Mississippian Besa River Formation argillite. Fluorite, associated with witherite, barytocalcite and barite, is present as replacement bodies, breccia fillings and minor veins.

Jan 1, 1984

By P. C. Thurston, T. Setterfield, D. H. Watkinson

"The Maybrun copper deposit IS In a succession of pillowed basaltic flows in the Wabigoon sub-province, northwestern Ontario. The rocks have primary flow morphologies and remarkably well-preserved crystallization textures, including quench-textured plagioclase, in spite of metamorphism to the amphibolite facies. The sulphide assemblage chalcopyrite-pyrrhotite-cubanite with minor sphalerite and pyrite is primarily in interpillow spaces and is stratabound. Basaltic rocks immediately enclosing the copper sulphide minerals have an enrichment in Fe, Mg and K and depletion in Ca and Na relative to surrounding flows. The Maybrun deposit is interpreted to have formed contemporaneously with volcanism and alteration, and was subsequently metamorphosed with the enclosing basalts.IntroductionThe association o f significant base metal accumulations with mafic submarine flows in the Archean is as yet poorly documented. Such deposits, where noted, have typically been small, and are therefore commonly over looked. The Maybrun Mine, a 2.6 x 106-tonne copper deposit in pillowed basalt, has many similarities with large, well-documented volcanogenic deposits. Given the interpretation of the Maybrun Mine to be volcanogenic in origin, there is n o reason why similar processes could not produce large deposit s. This is an important realization in an area where Archean submarine mafic rock s are very common, but frequently are examined only superficially. As gold commonly occurs in deposits such as Maybrun, even modest-sized deposits may be economic. The basalts at Maybrun are remarkable for amphibolite-facies rocks because of their extremely well-preserved delicate volcanic textures, including quench textures.The Maybrun Mine is one kilometre south of Atikwa Lake, in the Wabigoon sub-province of the Superior structural province, 75 km southeast of Kenora, northwestern Ontario, at longitude 93°35'W, latitude 49°25'N (Davies, 1973). Archean metavolcanic and metasedimentary rocks and intrusions underlie the area. Goodwin (1970) concluded that the mafic and minor felsic metavolcanic rocks, as well as the overlying metasedimentary rock s, were an eastward extension of the lower cycle of the Keewatin type section for the Lake of the Woods area. He estimated that the stratigraphic thickness of Keewatin rock s in this area is about 6900 m, of which 87% is basalt. The flows contain numerous interlayered sills, predominantly of basaltic composition; they have been extensively folded, faulted, metamorphosed to amphibolite facies and intruded by numerous felsic bodies, most importantly the Atikwa Batholith."

Jan 1, 1983

To determine the optimal circuit configuration for gravity gold recovery consideration should be given to a range of factors in addition to the efficiency of the gravity circuit, including capital costs, ease of operation and impact on comminution. The most common gravity gold circuits utilise a centrifugal concentrator treating a portion of the hydrocyclone underflow. This paper will examine this option and alternative circuit configurations to illustrate the effect of various gravity circuit feed and tailings configurations on the equipment sizing, capital costs, operating costs, water balance, comminution efficiency and gravity gold recovery. The optimum circuit configuration can provide reduced capital and operating costs, maximise gravity gold recovery and improve comminution efficiency.

Jan 1, 2011

By D. S. Hines

The purchase of mechanical equipment for mines is not unlike the purchase of other materials or supplies in general principle, but on account of the major part such equipment plays in the operations, and of the fact that life and valuable property are at stake, the matter demands the most careful attention on the part of the purchaser. The problems and difficulties encountered are dealt with below in their sequence in the purchasing procedure. Requisiting Although it is quite a common practice to submit a tentative specification of requirements to recognized manufacturers of equipment- soliciting alternative propositions or recommendations for study in the selection of certain equipment-as a rule the first step in purchasing procedure is the requisition. Primarily, it is the form that carries to the purchasing department the record of equipment wanted. A full and complete description or specification, and accuracy of record, are the important points to be insisted on in a requisition. Too much attention cannot be given to this detail, as this is one of 'the most important phases of purchasing work. Incomplete information, either in specification or detail, leads to delay in handling the requisition, and, if not detected in the purchasing department, may mean receipt of material which cannot be used for the purpose intended. In addition to description of material or equipment to be ordered, the requisition should also show where or what the equipment is for, whether for operating or new work. If for capital account, the number of the authority for expenditure should be given for record and distribution purposes.

Jan 1, 1930

By G. E. Agar

"The distribution of gold in the grinding-classification circuit of an operating gold plant was determined by assaying the size fractions of samples from each of the streams. This analysis identified the streams with the maximum potential for gravity recovery of gold and revealed that there was up 110 seventy-five times as much gold in the primary cyclone underflow as in the concentrator feed.Laboratory jigging and tabling tests were done on samples from two of the streams to determine what the recovery might be with a gravity circuit and to show that a high grade concentrate could be produced. A numerical simulation procedure was used to calculate a material balance for a circuit that included gravity separation on the primary cyclone underflow. The numerical simulation optimistically indicated that as much as 84% of the gold might be recovered in a reasonable grade of concentrate even though the recovery in batch bench scale tests was only 14%.Incorporation of a gravity separation device would reduce the inventory of gold in the grinding-classification circuit.INTRODUCTIONMany gold concentrating plants include a gravity concentration operation while others do not and the reasons that some do and some do not is not clear. Some of the advantages and disadvantages of gravity circuits are discussed by Penman (Penman 1987) without clear cut resolution. Penman's comments elicited an interesting response from Lloyd (1989) who produced a simple way to determine if the addition of a gravity concentration circuit would enhance the recovery of gold. Lloyd's method does not consider the cost of running the circuit so it only partially answers the question. There are reports in the literature (Wells and Patel 1991, Matwijenko 1988) that as much as 60% of the entire production comes from a gravity circuit when it is used, and that the grade of the concentrate produced often exceeds 65% gold, an assay that far exceeds most Merrill-Crowe precipitates that are sent to refining. In at least one instance (Hood 1984) a range of recovery from 40-50% was indicated from laboratory test work and the plant subsequently realized recoveries in the range of 26-40%. Despite these favorable numbers other plants use gravity separation when as little as 20% of the gold is recovered in the gravity concentrate (Carter 1992)."

Jan 1, 1993

By J. W. Merks

"Simulation is the process of designing a computerized model, of a system or procedure, for the purpose of understanding its behaviour and developing strategies to control its operation. Simulation models are rapidly becoming an effective tool for mineral processing plants. Powerful software and fast hardware are more readily available than a basic understanding of the theory of mathematical probability and applied statistics that process simulation models demand.Simple spreadsheet software can be used to develop simulation models that take into account any set of conditions at a mineral processing plant. In addition to an unbiased estimate for each variable in the set on which two-and three-product formulas are based, reliable variance estimates for all variables are required. How to estimate variances, effectively and at the lowest possible cost, and how to compute variances for simple functions such as the metal content of a quantity of ore or concentrate, or more complex functions such as the percentage recovery at a mineral processing plant, are the key to useful simulation models.IntroductionSimulation models for systems and procedures have become one of the most powerful and effective applications for computers( 2.6). Simulations are applied to a wide range of scientific and engineering disciplines. Generally, a model is designed to investigate the effects of changes in and interactions between a set of variables before a system is in operation or a procedure is implemented, by simulating weeks, months, and even years of operation, in a few minutes of computer time. Along with practical and useful applications always comeabuse and misuse. For a simulation process cannot be more reliable than the methodology that was applied to design the model, to estimate variables and variances, to check performance, and to verify validity. A mineral processing plant is a dynamic system that changes continuously as a function of time but within probabilistic constraints that can be estimated by applying statistical tools and techniques to the variables and variances that interact in the system.A model should be designed to simulate not only the set of variables but also the variance for each variable. Models in which constant variances are used to generate normally distributed random numbers, are less realistic than models in which the variances are simulated first, and then used to simulate the variables."

Jan 1, 1991

"INTRODUCTION Secondary mine ventilation has been hamstrung by the availability of fans that satisfy many competing operational factors. The sometimes legislated requirement of adequate volume to the working face, the minimisation of excavation required to fit the selected secondary fan and the power requirements of various operational phases has, in the past, not been satisfied with just one system. The new system being introduced overcomes all these competing requirements in one simple unit with an added bonus of being very durable without loss of performance when wear occurs on the impeller. Existing Operational Situation Several studies (e.g., CIPEC, 2005; LCG Energy Management Group, 2009) have found that between 42% and 49% of mining energy costs are associated with mine ventilation, depending on the type of mine and the equipment used. If we then look at the general breakdown of installed power of the secondary fan to primary vent fans, the ratio is around 2:1. Thus the total energy costs of the secondary ventilation represents about 25% of the overall mining energy costs. It is of interest to note that the cost of running a typical two stage axial vs the cost of purchasing and general maintenance cost of the same fan over a 10 year period, the breakdown will be conservatively in the order of 40:1.The currently available secondary ventilation axial fan have one duty curve at any given time. Generally this can be changed manually within the motor power parameters but requires a minor outage and removal of the fan to do the pitch adjustments. As the bag vent ducts grow longer, the supplied air reduces to a point where inadequate air is supplied to the working face. This is exacerbated by underground equipment putting additional resistance in the heading and further reducing the supplied air at the working face. This shortfall is normally corrected by the installation of an additional fan in the system to overcome losses in the bag system but comes at a cost of production as the heading needs to be shutdown to install the second fan. This also means that the heading is supplied with excessive air on the shorter runs with a wastage of fan power."

Jan 1, 2019

By F. Habashi

"While bioleaching of pyrite concentrates has been successfully used in industry to liberate gold from the sulphide matrix for subsequent cyanidation, the same technology cannot be recommended for leaching chalcopyrite concentrates for copper recovery. It will be shown to be uneconomical and cannot compete with pressure leaching technology. Data on the pilot plants that were constructed for this purpose and were shut down will be given.INTRODUCTIONBacterial leaching has been successfully applied for heap leaching of low-grade copper ores (Habashi, 1978, 1999). One of the major operations is that at Bingham in Utah (Figure 1). The leach solution collected at the bottom of the heap is extracted by organic solvents and the strip solution is electrolyzed to get high purity copper. The process was extended to treat auriferous pyrite concentrates to liberate gold and render it amenable to cyanidation by a process known as BIOX (Marsden & House, 2006; Lunt & Briggs, 2005).BIOX plants currently or recently in operation are the following:??Ashanti Goldfields Company, Ghana. Designed with an initial capacity of treating 720 tonnes of concentrate per day, the Sansu plant has since been expanded and currently has four modules processing 960 tonnes per day in all. It is by far the largest biooxidation plant in the world. The capital cost of the plant totalled US $25 million (1994 terms) and the operating cost is currently US $17/tonne milled.??Fairview, South Africa. The plant at the Fairview mine in Barberton, which was the initial pilot plant, has been fully operational since 1986. It was originally designed to treat 10 tonnes/day of concentrate but with the success of the project this has been increased to 55 tonnes per day. With the purchase of Fairview by Avgold’s Eastern Transvaal Consolidated, Avgold concluded a licensing agreement with Gold Fields, formerly known as Gencor, entitling it to use the BIOX technology to treat itsconcentrate.??Saõ Bento, Brazil. A BIOX plant was recently in operation in Brazil at the Saõ Bento Mine where a pressure oxidation circuit is used to treat the refractory flotation concentrate. This plant has confirmed the viability of combining bio-oxidation with pressure oxidation as a cost-effective method ofincreasing capacity at an existing oxidation plant.??Wiluna, Australia. The plant at Wiluna Gold Mine, Western Australia, was commissioned in 1993. Although originally designed to treat 115 tonnes per day of concentrate this has subsequently been increased to 158.??Other plants at Tamboraque in Peru, Harbour Lights and at Youanami in Australia have been commissioned recently."

Jan 1, 2012

By Lloyd H. Yeomans

"This paper will cover recent developments in conveyor applications with specific reference to capacities, bell speeds and distances. It will also discuss certain unique arrangements of horizontal, curved and loop belt systems. In addition, the recent changes in safety factors resulting from new conveyor construction methods will be reviewed.IntroductionConveyor belt systems are currently undergoing dramatic changes. Their use is being extended to providing a viable means for the transportation of bulk material over longer and longer distances.In this paper, a brief account of the historical development' of the belt is outlined, demonstrating how conveyor technology has adapted to changing market demands.Today, energy and environmental requirements are providing what may even be greater challenges. The ability of the belt conveyor to transport material and meet those requirements, places it in the position of replacing many conventional means of bulk material transportation.The paper also outlines some of the progress which has been recently made in this regard and includes a broad approach to the subject of belt design and application.Recent design developments have greatly extended the potential of conveyor belt systems to include applications thought impossible just a few years ago.Graphically illustrating the potential of this new technology IS a belting system currently operating in New Caledonia. Built in 1970, the system has an incredible centre distance of 43,000 ft, or about eight miles.Not to be outdone, the British Coal Board is currently constructing a belt system with a centre distance of 49,000 ft and a speed of 1,650 feet-per-minute. This system is expected to be completed in 1986.These innovative advances contrast dramatically to the conveyor belt's beginnings in the early industrial revolution. Oliver Evans, writing in the 1795 edition of 'Miller's Guide' defined the conveyor belt as a ""broad endless strap of thin pliant leather or canvas, revolving on two pulleys in a case or trough.""Obviously, the conveyor belt has come a long way since those early days."

Jan 1, 1983

By Eric L. Hoffman

Sample preparation technology changes Rock Soil Vegetation Analytical Innovation Assay or Geochem Choice of Digestions Choice of analytical method Whats new in analytical technology? Innovations in surface Geochemical Methods Hydrogeochemistry Biogeochemistry Soil Gas Hydrocarbons (SGH) Selective Extractions Glacial Environment Arid Environment

May 1, 2008

By J. Palarski

In the Polish coal mining industry, the use of mine waste in underground backfill has been the most common means of providing ground support to minimize surface subsidence, increasing extraction ratios, and reducing the quantity of waste for surface disposal. Over the last decade attention has been focused on the use of different waste as filling material of underground workings and grouting of roof fall rocks in caving area. In the paper, a brief history of the development of fill technology in Polish coal mining industry is presented. Next, the paper discusses various criteria that should be taken under consideration in the preparation process of a fill slurry and grout, fill distribution systems, mining geometry and placement methods. Moreover, in the paper evaluation of the potential of utilizing coarse and fine waste as a resource material in the production of a backfill slurry and grout for filling and injection in abandoned mines is presented.

May 1, 2007