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Liebherr Mining Equipment Co., of Newport News, VA and Baxter Springs, KS, introduced the T282, a new two-axle, diesel-electric, AC drive haul truck with a payload capacity of 327-t (360-st). The T282 was unveiled at a press briefing in October 1998 at the company's Baxter Springs research and development1 manufacturing facility. In addition to an increase in pay- load capacity, the truck's AC drive system has been de- signed to allow for easy configuration to a trolley-assist system with minimal additional equipment. The T282 provides fuel savings, reduced maintenance requirements, and reduced downtime and maintenance costs, providing the mine operator with increases in productivity. Basic dimensions and weight of the T282 are: ? Overall length, 14.5 m (47.5 ft). ? Overall width, 8.7 m (28.7 ft). ? Loading height, 6.5 m (21.2 ft). ? Height - body up, 13.9 m (45.9 ft). ? Empty vehicle weight, 201 t (221 st). ? Operating weight - loaded, 528.6 t (582.6 st). ?Engine, Detroit Diesel 16V4000 at 2 MW (2,750 hp). ?Electric drive system, Siemens/Liebherr.

Jan 1, 1999

By J. E. Hoffman, T. J. Keefe, Michael E. Stout, O&apos

M.A. Industries, Inc. has developed and is now offering on a commercially available basis, complete systems to recover and recycle lead from spent SLI batteries. The system begins with the breaking and separation of the component parts of the batteries and subsequent treatment of the effluent water produced by this operation. The recyclable materials recovered from this process are metallic lead, lead paste and polypropylene. The lead paste is introduced into a process to convert it from a lead sulfate to a lead carbonate. The process also regenerates the salt solutions into reusable carbonate. The lead carbonate is then leached into an acid bath where it is later recovered by a proprietary electrolytic process. The metallic lead is recovered in a short rotary furnace producing metal for further refining and alloying. The polypropylene is further washed and then introduced to a reclaim extruder along with the proper modifiers and additives. The resulting resin can then be sold on the open market to injection molding processors. This complete system greatly reduces the amount of waste to be disposed of and completely complies with all applicable EPA guidelines.

Jan 1, 1993

By R. H. Seraphim

The name is derived from an Egyptian myth, "A beautiful lone bird which lived in the Arabian desert for 500 or 600 years and then consumed itself in fire, rising renewed from the ashes to start another long life." HISTORY This account of the first history is gleaned from old reports and documents which are listed in the Bibliography and from discussions with old-timers of the district. Prospectors were active in the vicinity of Greenwood in 189 1, and in that year staked the Mother Lode, Crown Silver, and Sunset. Henry White staked the Knob Hill claim in Phoenix on Jul. 15, 1891, and by the end of the year, other prospectors had staked most of the claims covering the valuable ore bodies in the camp. Much surface work done in the early years indicated that the values in copper, gold, and silver were low. Large capital investments were required to develop the ore bodies and build smelters. The discovery that the ore was practically self-fluxing greatly enhanced the value of the deposits. A map of the area showing the geology is given in Fig. 1. The bedded Brooklyn conglomerate is shown in Fig. 2.

Jan 1, 1991

By James J. Brady, James S. Lewis, Robert B. Gordon, Jimmy W. Honeycutt

INTRODUCTION Tunnel construction has always been an extremely high risk form of contracting primarily due to the inaccessability of information concerning the ground conditions to be encountered during excavation. We certainly make every effort to overcome this problem through borings, geological research, site visits, etc.; but at best owners, engineers and contractors alike are only able to interpolate a relatively small amount of factual data from isolated sections of the project into a forecast of ground conditions for the entire project. In essence this becomes an "educated guessing game" with risk to reward ratios (and subsequently the bid price) in direct relationship to the contractor's confidence in the quality of the guess. In many instances it is economically or physically infeasible to obtain information and of course the total picture is never known until the project is complete. This problem effects the contract format as well as price. The contractor's ability to handle unforseen problems on the project become extremely important as to the project's overall success. The following pages contain an actual case history of a project which affords an excellent example of the entire spectrum of situations resulting from tunnel construction in difficult ground conditions.

Jan 1, 1983

By Juan P. Camus

One of the most important decisions in mine development is the selection of the mining method. Open pit or underground methods are selected depending on the shape of the deposit, and its position with respect to the surface. When the decision is not clear or evident, then the common rule is to compare underground and open pit projects to choose the one which yields the maximum return. However, in some circumstances' the best alternative is to start-up the operation with an open pit until a point where mine operating costs make more convenient to employ an underground method. In this case, the final pit limit is not directly related with commodity prices and its position is a funtion of capital and operating costs associated with both methods. The goal of this paper is a mans of establishing the proper ultimate pit considering a potential underground mine. The methodology is quite simple and can be implemented to work with a variety of available routines for pit optimization, such as Lerchs-Grossmann, floating cone, network flow and the Lemieux moving cone optimizing algorithm, which is the tool used by the author.

Jan 1, 1992

By F. Chavan

1. Introduction The new Cleuson-Dixence development project in the Valais region of the Swiss Alps, involves the construction of a new link between the Grande-Dixence dam (still world recordholder with a height of 300 m) and a power house on the banks of the Rhone consisting of approximately 20 km tunnels and shafts, and involving a fall of about 1900 m. This 1200 MW project will replace an existing 900 MW structure built in the 1960s, no longer considered efficient. The new project comprises a head race drift about 15.8 km long, a surge tank, an inclined cascade shaft 4,2 km long, and an underground power station. The work for lots C and D (head race drift from Tortin to Tracouet, surge tank, six adits ans the complete inclined shaft) was awarded to our group (Prader, Locher, SELL, Losinger, Evéquoz, Dénériaz, Imboden and Bouygues). The geological conditions are: Lower part of the shaft (300 m) : sedimentary - sandstone and soft tertiary sandstone. Middle and upper part (2600 m) : metamorphic - upper and lower carboniferous, interrupted by triasic chipping. The horizontal section (7 km) consists of mica

Jan 1, 1995

By N. E. Green, W. E. Bennett, G. P. Harrison

INTRODUCTION The art of raise boring has seen rapid development and use in underground mines both for primary development and production during the past 10 years. The intensive full scale tests by a major mining company in the Precambrian rocks of the Sudbury district of Ontario, Canada, have lead the way to the general acceptance of the raise drills. The rock successfully raise bored in the Sudbury area has compressive strengths varying from 30,000 to 50,000 p.s.i. As a result of the intensive study, it became evident to many mining companies that raise boring could be adapted to many mining systems. Many companies have modified their planned mining methods to incorporate raise boring. The result has been a more rapid development of their mine and naturally, an economic advantage to them. In conjunction with the acceptance of the raise drills, the range of equipment has broadened in terms of size, capability and efficiency. The concept of raise drilling and the general arrangement of the equipment has seen little change. At some locations there have been reported successes of drilling pilot holes up

Jan 1, 1997

By L. W. Scott, T. H. Dubaniewicz, F. T. Duda, P. G. Kovalchik

Recent research conducted by NIOSH's Pittsburgh Re¬search Laboratory showed that electrical current levels permitted under present regulations may not limit cable temperatures to less than 90°C in reeled trailing cables. Reeled cables, which are tightly wrapped with many turns and which carry current in an enclosed space, can become overheated due to poor heat transfer. This overheating can cause the cable insulation to soften, making them prone to damage. The damaged insulation reduces the life of the cable and can lead to shock, electrocution and mine fires. This paper describes a method of measuring the conductor tem¬perature of mine trailing cables during normal operation. The temperature is measured using a 50/125-, µm graded index multimode optical fiber located in the center of the metallic conductors. Distributed temperature measurements are made using an optical time domain reflectometer (OTDR). This system is capable of measuring temperatures with an accuracy of ± I °C over a length of 4 km at I -mintervals. With this unique way of measuring temperature, tests can be conducted that simulate actual mine conditions. The tests provide important data that allows MSHA's Approval and Certification Center to develop approval criteria for cycli-

Jan 1, 2000

By W. E. (Bill) Stanley

Introduction This is an exciting day. It isn't often that you can find the best minds in a particular business gathered together in one place. But that is what we have here. You are the best and the brightest people there are in the business of gold mining. What we discuss at this conference confirms the major issues facing us and sets out the issues governing how our mines and mining companies will be run in the next few years. In looking over the list of papers to be given, I have noticed something. It is something that I have noticed at almost every mining convention I have ever attended. Almost every paper at this conference concerns itself with the technical side of mining. Most of us in this roan are professionals; we are either engineers, geologists, accountants or representatives of some other profession. In getting where we are today, we have had to work hard to acquire the technical skills needed for our individual professions. We are all proud of our knowledge and work hard to claim the right to be considered an expert in a particular technical field or subject area.

Jan 1, 1987

By A. Foscolos

Land reclamation and rehabilitation of depleted coal mines in the wider area of Ptolemais-Amynteon is practiced by the Division of Mines of the Public Power Corporation of Greece in order to conform to the concept of environmentally sustainable economic development of its operations. Detailed chemical and mineralogical studies were performed on reclaimed soils and their crops in order to evaluate the results of land reclamation and rehabilitation while similar studies were undertaken in adjacent, regularly cultivated, soils. Results indicate that trace element concentrations as well as concentrations of elements of environmental concern to be higher in regularly cultivated soils than the reclaimed ones. However, the concentration of the elements in wheat grains harvested from both, regular and reclaimed, group of soils is the same. The reason for this behavior is the very low water solubility, of the elements in the soils, due to their high pH values and the nature of their occurrence. As a result, wheat crops produced from reclaimed-rehabilitated soils developed on depleted lignite mines in the wider area of Ptolemais-Amynteon do not pose any health problem on either humans or animals when consumed.

Jan 1, 2003

By Stanislaw Nawrat, Waclaw Trutwin, Waclaw Dziurznski, Janusz Roszkowski

In recent years attempts have been made to fight open and intensive mine fires by the use of special extinguishers, which are able to produce great volumes of inert gases directed into the fire zone. These extinguishers are derived from turbo-jet engines used in aircrafts and adopted for operations in mine conditions. The purpose of this paper is to draw the attention to a computer simulation method, enabling studies of dynamical behaviour of mine ventilation processes disturbed by open fires, which are also influenced by measures taken during fire fighting actions i.a. the mentioned operating extinguishers. The first part of this paper gives an account of the principles on which the computer simulation program, concerning the non- steady mine ventilation process, the fire as a heat source and the extinguisher as a source of inert gas and moisture has been based. The next part of this paper deals with simplifying assumptions and the subsequent limitations of the derived simulation pro- gram. Finally, from an example of a computer simulation, the results will be presented and relations shown between parameters characterising the ventilation process during the fire fighting action.

Jan 1, 1997

By C. Ceccarini, I. Salvadori, G. Oggiano

GENERAL BACKGROUND The first mention of the presence of bauxite in the mesozoic series of north-west Sardinia (fig. 1) is owed to Oosterbaan, a Dutch geologist, who carried out a geological survey of the area in the ninetten thirties. A more detailed study of the mesozoic series was attempted in the fifties by Pecorini and other, who concentrated particularly upon the stratigraphy of the bauxitic horizons, through examination of the various outcrops. In the sixties a pining company, Monte Amiata S.p.A., turned its attention to a section of the deposit outcropping near Olmedo and, considering it to be of some promise, carried out prospecting works consisting essentially of various trenches, some bore holes, a few adit and a. layout plan for the preparation and execution of trial exploitation. The results, although positive, did not convince the company's shareholders to continue the exploration. This report, which is intended as a new contribution to knowledge of the Sardinian bauxite deposit, takes into account the information acquired not only from a drilling prospection begun in 1979 in connection with the SOMIT-PROGEMISA joint venture, but also the results of structural studies and numerous chemical, mineralogical and

Jan 1, 1984

By W. X. Wang, O. Stephansson

In the mining and quarry industries, rock fragments are often transported by conveyor belt. To estimate the qualities of the rock fragments (i.e., size distribution and shape), an operator must take samples from the conveyor and manually perform a sieve analysis, which is time-consuming and tedious. Alternatively, an image-analysis system can be used to monitor the fragment quality on a fast moving conveyor belt. However, images of fragments on a fast moving belt vary to such a degree that the quality of any two successive images are not the same, and some of the images are of such poor quality that they are unrecognizable by human eyes. If poor-quality images are directly analyzed by a segmentation algorithm, the analysis will not be satisfactory. To resolve this problem, it is necessary to use an image-classification program for the automatic selection of fragment images with good quality. Because of this need, an image-classification program was developed and tested both in the laboratory and in the field Testing of the system on different types of fragments showed that the system works reasonably well.

Jan 1, 1997

By D. J. Shields

This paper describes a dynamic short-nun mineral supply model that incorporates secondary processing, transportation, mineral market structure, and direct mining and milling costs. The method employed is network flow programming. Empirical tests utilizing domestic phosphate industry data have been conducted by the Bureau of Mines, U.S. Department of the Interior. In the model, nodes represent physical locations such as a mine or port. Arcs represent either a process, such as mining, or movement, such as rail or barge transport. Each arc is described by lower or minims allowable flow bounds, upper or maximum possible flow bands, and variable cost. Mines and previous period inventories represent potential supply. The model is optimized via a cost minimizing algorithm, which attempts to fulfill stated total demand at the minimum possible system cost given the arc constraints. An optimal solution of the model will predict production patterns by mineral property for each prespecified level of demand. A mineral property is defined as a separate accounting entity such as a mine. The results of serial optimizations are used to construct the short-run supply curve. Dynamic policy analysis can be conducted by altering the arc constraints.

Jan 1, 1986

By Hajime Miki, Michael J. Nicol

Relatively simple techniques have been developed which enable the electrochemistry of sulfide minerals to be studied with particles varying in size from above 100 pm to less than 1 pm. Both oxidative and reductive processes have been studied wing the minerals pyrite, arsenopyrite and chalcopyrite. It has been shown that it is possible to completely oxidise or reduce the minerals during a single voltammetic sweep. The resulting voltammogram produces peaks which are characteristic of each mineral and can be used to qualitatively identify the minerals. In the case of chalcopyrite, it has been demonstrated that the charge involved in the anodic oxidation can be quantitatively related to the amount of copper dissolved. Quantitative information can be obtained using peak fitting techniques. Interesting differences in the behaviour of the minerals in sulfuric and hydrochloric acids have been observed, particularly in the case of pyrite for which a second major peak is obtained which has been attributed to the oxidation of elemental sulfur in the presence of chloride ions. The technique offers the possibility of providing mineralogical information of individual particles based on an electrochemical voltammetic finger print.

Jan 1, 2005

By Bernardo Portillo, Alejandro Perez, Daniel Norrgran, Joseph Wernham

High gradient permanent magnetic separators (termed "Ferrous Wheel") are described as used to recover the iron bearing minerals from mill tailings at the Grupo Acerero del Norte's Hercules iron mines in Coahuila, Mexico. The pilot scale test work as well as the "in-plant" test work provided the basis for a 385 MTPH plant expansion to be commissioned late in 1995. Approximately 6 million metric tons of flotation tailings averaging 50 percent iron, mostly as hematite, are contained in two separate ponds. The tailings are relatively fine at 93 percent -200 mesh and 72 percent -500 mesh. After testing various recovery methods, a high gradient permanent magnetic separator was selected to produce a preconcentrate prior to flotation. The separator uses a flux converging matrix to generate high gradient magnetic fields and capture the hematite. The advantage of the Ferrous Wheel high gradient permanent magnetic separator is the use of permanent magnets as opposed to electro-magnets. Further the vertical rotating ring is much more conducive to matrix cleaning as opposed to the conventional horizontal ring separators. This feature also allows the use of a wide range of matrix materials to achieve the optimum metallurgical response

Jan 1, 1995

By Poltak Sinaga

PT Kaltim Prima Coal's 13.1 km overland conveyor was commissioned in 1991. It is of conventional 3 roller 350 troughed belt type. Cost and performance optimisation during initial design ended up with 5.4m/s belt speed, 1,000mm belt width to convey 1,350tph, and 7mtpa of coal. Despite high initial figure, the belt speed was lifted to 6.5 mps in 1996 to accommodate mine throughput increase. In 2002, new low loss ST2100 1,100mm wide belt replaced the old ST2250 due for change-out. An upgrade project was initiated at the end of 2003 to further increase the belt speed to 8.5 mps, hence to increase the OLC capacity to 30mtpa. Performance data, experience of site personnel, site observation and tests, benchmarking, and information from equipment manufacturers were major inputs to the design review. The project fast track was another challenge in addition to executing modifications on a production lifeline. The project was completed within fifteen months and the OLC was successfully commissioned at 8.5 mps belt speed in February 2005. The OLC has been to date conveying 4200tph satisfactorily.

Jan 1, 2008

By Kenneth F. Lane

In most industries it is normal commercial policy to try to gear production to the market. In times of scarcity output is pushed to its maximum and in times of glut output is reduced. Because of the effects of supply and demand, these times correspond to times of high and low prices respectively so the policy results in maximising long run total profits. Stockpiling is often an integral part of the policy. Stocks are accumulated during depressed market conditions and sold off when demand revives. This further increases the long run total profits. However, such policies cause violent fluctuations in short term profitability and impose severe financial strains. Indeed planning and implementing the policies are a central management concern which is often critical to the success of the industry. The mining industry is no exception and, for many raw materials, trying to balance supply with demand is an international problem. Stockpiling and restricted production agreements are common elements of policy. But very little attention has been paid to the one additional control which is unique to the mining industry, namely, the cut off grade. This neglect is apparent at all levels from individual mines to national economies.

Jan 1, 1979

By John D. Shaw

1. Introduction 2. The Hydraulic Mine _ (i ) Development (i i ) Extraction ( i i i ) Transport 3. The Water Circuit 4. Manpower and Results 5. Modifications 6. Conclusions 1. Introduction The Kaiser Resources Ltd. hydraulic coal mine is located in south eastern British Columbia, Canada, at the western end of the Crowsnest Pass, next to the Town of Sparwood. The seam presently being mined is the number 10, known locally as the Balmer seam, which is a high quality coking coal, 50 feet in thickness and of an average inclination of 35 degrees. The mine was designed in the late sixties as a small scale trial unit, and was to use a single monitor unit, working 3 shifts per day on a 5 day per week basis. Experience has proved the method to be so successful as to warrant the expansion of the ancilliary facilities to cater for the increased production. The annual raw coal production from this single monitor unit has risen from 108,988 short tons in 1970 to 942,334 short tons in 1975, with a total mine labour force of about 160 men including the surface de-watering plant, mine supervision and mine administration.

Jan 1, 1977

By Kenneth N. Han, Yuhong Chen

The removal of carbonaceous material from Carlin gold ore has been investigated via froth flotation. The effect of type and concentration of various oils as flotation collectors and of sodium silicate as the dispersion agent on the overall recovery of carbonaceous material has been studied. Other variables affecting froth flotation efficiency were also examined closely. These included particle size, pH of the solution, and temperature. The effect of reduction and oxidation of carbonaceous material on froth flotation efficiency has also been investigated. This investigation showed that aromatic type oil was the most effective collector. Also found in this investigation was that oxidized carbonaceous material was difficult to float unless the oxidized portion was subject to reduction before flotation. More than fifty percent of the carbonaceous material was able to be removed via froth flotation. It can be concluded from this study that the effect of pH and temperature during the rougher flotation state is of little significance to the overall recovery of carbonaceous material. Since pyrite is responsible for the high consumption of chlorine, removal of pyrite is very important in order to reduce the overall consumption of chlorine.

Jan 1, 1990