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By Pierre-Yves Morvan

One of the numerous challenge for underwater mining is the positioning. This paper describes an architecture for the integration of an Ultra Short BaseLine (USBL), an Acoustic Synthetic BaseLine (ASBL) operating in Sparse Array mode and a Doppler Velocity Log (DVL) closely coupled with an Inertial Navigation System (INS) for precise subsea positioning in severe environments. By using such architectures, the INS can help to reduce the noise on the measurements coming from acoustic sensors. Another advantage is the capability to reduce the number of required transponders on the seabed, and as a consequence, reduce the time for the deployment and calibration of each transponder. The paper further describes sea-trials performed to assess the ability of a complete positioning system to provide decimetric positioning precision even with a single beacon deployed in the navigation area.

Jan 1, 2017

By M N. Mian

The Cayeli volcanogenic massive sulphide deposit is located in Black Sea region of Turkey. Cayeli Bakir Isletmeleri (CBI) was formed as a joint venture between Inmet (Canada) and Eti Holding (Turkey). CBI is processing complex copper/zinc sulphide ores. The Cayeli concentrator was commissioned in 1994, with a design capacity of 600 000 tonnes/year. The grinding circuit was a classical rod mill/ball mill combination. The rod mill was converted to a primary ball mill in May 1997. The reasons for conversion were to use mill power more efficiently and eliminate feed interruptions during rod charging. The grinding circuit now has a primary ball mill in open circuit, and a secondary ball mill in closed circuit with hydrocyclones. Classification was originally done in two stages with hydrocyclones. Both mill discharges were combined and pumped to a primary cyclopack having two, 500 mm diameter cyclones. Primary cyclone overflow was pumped to a secondary cyclopack for further classification. The secondary cyclopack had ten, 200 mm cyclones. Both unit underflows were fed to a secondary ball mill by gravity. The secondary cyclone overflow, typically 62-64 per cent passing 36 ¦m, at around 42 per cent solids (w/w) was fed to flotation circuit. In order to increase circuit capacity to 1 000 000 tonnes/year and to improve control over the grinding circuit, it was decided to convert the classification circuit from two stage to one stage. For this purpose, six Warman Cavex cyclones having 400 mm diameter were installed. Now, the combined primary and secondary ball mill discharge was classified in single stage with the Warman cyclones in closed circuit with the secondary ball mill. The cyclone overflow goes directly to the copper rougher circuit as flotation feed. The grinding circuit is producing a flotation feed of 70 per cent passing 36 ¦m. The change over to single stage classification at Cayeli was successful. A mill throughput of 1 000 000 tonne/year is being achieved with better control over classification, and improved grind size. Results and comparison between the two classification circuits are presented in the paper.

Jan 1, 2003

By B. Ehgartner, M. Karmis, C. Haycocks

INTRODUCTION Interaction effects between mining operations developed on different levels of contiguously placed bedded deposits are a major problem in many parts of the United States. Efficient design criteria, derived from careful analysis of field studies as well as theoretical and model analysis, have shown that many problems that may result from seam interaction can be avoided, minimized, or on occasion used with beneficial results. Selection of seam mining sequence is rarely based only on ground control considerations, but rather on factors such as seam ownership, characteristics and accessibility. Therefore all possible mining sequences and methods must be considered in the development of multi-seam design criteria. Increased utilization of the longwall method of mining creates special problems in multi-seam mining due to the inevitability of caving and, therefore, subsidence. Considerable valuable experience has been gained in this direction from British mining operations where interaction problems are extremely common and the longwall method is the primary method used. However, limitations persist in the application of much of this information to U.S. conditions due to variation in layouts between advancing and retreating longwall systems and the inherent difference in the geologic environment. Considerable field data is available for U.S. room and pillar operations, and where successful pillaring operations have been carried out close parallels may be drawn with ground control mechanisms in longwall operations. VARIABLES AFFECTING INTERACTION Analysis of ground control multi-seam problems shows that factors contributing to interaction may be classified into variables that are fixed by the geo- logic environment and those that depend on engineering design. These may be described as follows (Haycocks et al, 1982): Fixed: (i) Depth*, (ii) Innerburden thickness*, (iii) Innerburden physical characteristics*, (iv) Stress field, (v) Seam thickness, (vi) Coal characteristics, (vii) Completed mining operations either above or below the seam to ve mined, and (viii) Age of workings. Mining: (i) Height, (ii) Dimensions and geometry*, (iii) Method*, and (iv) Spatial location of entries* *These variables are regarded as being critical effects. Few attempts have been made to quantify the variables controlling interaction. Dunham's (1978) linear regression analysis, combined with the National Coal Board's MRDE Roadway Monogram, is probably the most noteworthy. This study involved eighteen multi- seam longwall mines in the United Kingdom. The following variables were taken into account: seam depth, pillar width, opening shape, floor and roof conditions, rate of face advance, vertical seam interval, and age and geometry of overlying workings. A multi-linear regression analysis of these variables fitted by appropriate field values developed a prediction equation for lower seam stability. Although the study included many variables, it neglected the nature or geology of the innerburden. The prediction equation was found unreliable, but it did show the significance of geometry as a factor controlling lower seam stability. MINING SEQUENCES Irrespective of the type of mining method selected only four possible mining sequences are possible for two seams. Finlay and Winstanley wrote in 1934. .. "Experience has shown that whether the upper or lower seam was worked first, the subsequent working of the other seam in the same area seriously affected the roads in the seam first worked." Those effects depended upon the four basic mining sequences: 1) The upper seam is mined out prior to mining the underlying seam; i.e., the seams are mined sequentially downward and mining of the underlying seam is not commenced until operations above are completed and have ceased.

Jan 1, 1982

By R. D. Lindsay

"Pamour Porcupine Mines, Limited is involved in the mining, milling and primary refining of various gold, gold - copper and refractory gold ores. Pamour operates five mines in the Porcupine Mining District of Ontario, and two 2,550 t/d milling facilities.Both metallurgical facilities use conventional cyanidation technology including zinc cementation for precipitation of gold and silver from solution. The precipitation process, as applied to clarified leach solutions (less than 1 ppm suspended solids) at Pamour is called the Merrill - Crowe process. Precipitates from both milling operations are treated at Pamour's Area Refinery. Schumacher precipitates, unlike Pamour No. 1, require an ''Acid Treatment Stage"" prior to refining to remove the high contained copper. This is accomplished by leaching the precipitates initiallv with sulphuric acid to remove zinc and then with sulphuric acid and manganese dioxide to dissolve copper. Refining procedures after ''Acid Treatment"" are essentially the same for both precipitates.The following considerations highlight the basic principals applied to refining cyanidation precipitates at Pamour, including:"

Jan 1, 1986

By Roy EI. Durr, Glen R. Davidge

"This paper presents the results of structural analyses and full-scale destructive tests conducted on liner plate culverts. The purpose of this work was to establish a design method and evaluate the suitability of using these structures in potential roof-fall areas for a rehabilitation application in lower stress and relaxed mining environments. Field evaluation of the design is currently in progress.Theoretical ultimate resistance functions were established for two different culvert shapes and were found to be representative of their experimental behaviour. The ultimate resistance function was used to determine their plastic behaviour to a rapidly increasing deflection condition, to determine the energy absorption capacity of these structures, and to predict their response to impact loading.IntroductionThe Kidd Creek mine of Falconbridge Limited is located justnorth of Timmins, Ontario. The area under rehabilitation for which this program was developed is the 2600 level of the No. I mine. The problem of effectively securing selected drifts at the 2600 level in NO.1 mine, for access to a high-grade ore block, is key to the economics of the operation. Diamond drill test holes had indicated a loosened rock mass above the 2600 level of about 7.5 m thick in response to the extensive mining operation below this level. This level forms the arbitrary boundary between the No. I and No. 2 mines, and has extensive volumes of cemented rock fill below it and largely untouched ore above it to the 2000 level in the North orebody. The walls at that level were showing relaxed ground conditions typical of de-stress: sub-horizontal joints opening up, and peeling.Due to the ground conditions, the consequent safety risks, the high grade of the ore, the potential production delays, and the likelihood of several phases of rehabilitation, regularly used drift rehabilitation employing rock bolts, cable bolting, or shotcrete was not practical. Two options were deemed possible alternatives to suit these conditions, steel sets with blocking and lagging, and liner plate culverts with backfill. Culverts were chosen."

Jan 1, 1995

By Jiwei Duan

The energy transferred from a hammer to the pile top is considered as the effective energy in this paper. The effective energy is related to the pile dimensions, soil and pile-soil interface properties. This relation may be expressed as an equation based on the dimensionless theory. The relationship between pile capacity and effective energy was studied by performing a series of wave equation analyses using a commercial software called GRLWEAP (Wave Equation Analysis Program) by GRL Engineers, Inc. The results show that the pile capacity increases with the blow count when the effective energy is constant, however, it has a little change as the blow count is over 100 blows per foot. The pile capacity decreases as the ratio of pile penetration depth to pile diameter increases if the effective energy is constant. The pile capacity will increase as the pile diameter and wall thickness increases if the effective energy is constant. The pile stickout (pile length above the ground surface) does not have a significant effect on the effective energy and may be neglected. Curves for pile capacity versus effective energy are presented to be used for preliminary hammer selection according to effective energy and hammer efficiency. Finally, a case from PDA testing was studied. Measurements of the effective energy and pile capacity by CAPWAP were presented and compared with the results by GRLWEAP.

Jan 1, 2006

The difficulty of successfully imple menting a landscape policy is almost incom- prehensible. Landscape design is recognised as an essential component in the integration of engineering and architectural projects into the landscape, but the factors which prevent the achievement of a successful result are rarely recognised or assessed. In many cases these prohibiting factors are due to a lack of understanding of the effect of major planning decisions on the existing landscape, the importance of the landscape plan and the significance of appro- priate specified techniques to prevent un- necessary damage and to ensure retention of existing vegetation in a healthy condition. The role of the landscape architect in incorporating new land uses into the landscape provides the background against which factors which inhibit policy achievement can be con- sidered.

Jan 1, 1976

By C Gourdon

The present study concerns a new type of mixer-settler unit where coalescence is promoted by means of the phase inversion method (MSPI). Using two different systems (alkaline etching solution û LIX 54 in kerosene and acidic aqueous solution û LIX 984 in kerosene) the influence of the total flowrate, the A/O phase ratio and the hydrodynamic conditions in the nozzles of the scattering device on the extraction and separation efficiencies are studied. Two modes of operation are clearly outlined and a theoretical model predicting the separation efficiency is proposed and compared to experimental results. A comparison between mixer-settlers with classic decanters and the MSPI unit has demonstrated the advantages of the latter where throughputs in the range 20 -25 m3.m-2h-1 can be easily realised.

Jan 1, 2000

By G. Ranjan

The designers and the practicing engineers have started using latest and cost effective techniques of ground improvements which utilise the weak and poor sub-soil deposits efficiently for the civil engineering construction. In the present investigation, a new concept of 'skirted granular piles' has been advocated. An effective method of construction of granular piles as an economical alternative to vibroflot, and the skirt has been developed. The construction technique is based on indigeneous know how which effectively utilises the man-power technology avoiding import of costly equipment suiting to the developing countries. Full scale insitu tests have been carried out at four sites, having different soil conditions, on virgin weak sub-soil, and improved ground by casting plain and skirted granular piles. Effectiveness of different types of skirt has been demonstrated through insitu tests. A simple analytical approach has been proposed to predict the ultimate pile capacity. The predicted values of ultimate capacity have been found to demonstrate a good correspondance. Granular pile behaviour in terms of pile depth, diameter, spacing and stress deformation characteristics of the improved ground have been discussed. A significant improvement in ultimate capacity in improved ground has been noted. This is further augmented when granular pile group is skirted.

Jan 1, 2010

By Philip D. Wilson

SPEED is essentiaI in this war program and it is hard to keep up with developments. When the title of this paper was chosen, the contemplated magnesium production for which plants were then under construction was some 200,000 tons of metal per year or sixty times the 3350-ton production in prewar 1939. A few- days later an analysis of the President's 185,000-plane pro-gram, incendiary bomb schedules, and the additional requirements of the Army. Navy and Maritime Commission made it apparent that a much greater amount of magnesium must be provided in 1943. The new figures are huge but the censor will not per-mit their disclosure.

Jan 1, 1942

By Glenn Kosick, John Starkey, Glenn Dobby

"A practical new test has been developed for SAG hardness determination. Using two kilogram samples of minus one inch diamond drill core or crushed muck samples, the Starkey SAG Test has been shown to give accurate predictive information which directly relates to on-stream SAG mill performance. Typical results and test criteria are discussed in the paperAchievements to date include:• Identification of hardness profiles and the location of hard and soft zones in a large ore body.• Accurate prediction of the hardness of a bulk sample by using an adjacent diamond drill hole.• Derivation of a plotted curve relating pilot plant power to laboratory relative hardness.• Demonstration that for every test done to date, the Starkey SAG Test produced a product size distribution identical to that produced in a pilot plant or full scale plant SAG operation.This test can now be used for blast hardness monitoring and short term control of mine production in existing plants and for identifying the proper locations for bulk samples in new projects. In addition, new SAG mill design can now be rationalized in a low cost way to eliminate unforeseen production shortfalls.IntroductionThis paper is presented to introduce the Starkey SAG Test, a practical new laboratory tool for measuring the relative hardness of small ore samples in a semi-autogenous grinding (SAG) environment. The test was first designed for use on diamond drill core samples during the prefeasibility stage of new mining projects, to provide new information about the ore body at reasonable cost. It is a new tool and does not replace existing pilot plant test requirements.The test will also be useful for throughput prediction in existing SAG plants by assisting in short and long term mine planning, where forecasting of metal grades and milled tonnage is used to control mine profitability. Because in-plant hardness testing has previously been unavailable on small samples, this test offers exciting possibilities for SAG mill operations where hardness variation is or could be a problem.The Starkey SAG Test provides the following benefits to the mining industry"

Jan 1, 1994

By K. Osseo-Asare

Rate laws for the hydrogen reduction of metal ions are typically of the form: [r = -d[M(II)]/dt = k[M(II)]xPy2H] where k is an apparent rate constant, [M(II)] and PH2 represent dissolved metal concentration and hydrogen pressure respectively, while x = 0 - 1 and y = 0.5 - 2. Half-order dependences have been reported for some M(II)/H2 systems; however, no satisfactory explanations have been offered. In an effort to bridge this gap in our understanding, the published precipitation rate data (for M(II) = Cu(II), Ni(II), and Co(II)) are reviewed (with emphasis on the reported reaction orders) and compared with the corresponding but limited electrochemical polarization data. Based on the available literature on the electrochemical kinetics of the M/M(II) and H2/H+ systems it is demonstrated theoretically that, under certain conditions (e.g., in the presence of electron-conducting solids), the rate of the M(II)/H2 reaction can be expressed as: [-d[M2+]/dt = k[M2+]2/1P2/12H] It is concluded that electrochemical processes probably play an important role in the hydrogen reduction of metal ions, especially for systems that involve heterogeneous catalysis.

Jan 1, 2003

The Ertsberg (Gunung Bijih) Mining District is located in the core of the highlands of west New Guinea, an island long recognised as the product of a Cenozoic arccontinent collision. Geologic studies in the Central Ranges of the Papua Province of Indonesia (near Puncak Jaya, 4884 m) have revealed timing relationships, when combined with mechanical considerations, led to a refined model for the tectonomagmatic effects of collisional orogenesis and the formation of the spectacular Grasberg porphyry-type copper-gold (Cu-Au) deposit.   An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By R. L. Wiegel

There are approximately 40 million tons per year of phosphate rock produced in the United States, half of it by flotation. The bulk of this is used to produce diammonium phosphate, an essential ingredient in the commercial fertilizer mixes used by the thriving U.S. agricultural community. This paper describes the mineral beneficiation practices of the phosphate industry, with special emphasis on flotation. There is also an attempt to include those items that might be considered emerging technologies for the industry as it faces the problems of a diminishing high-grade reserve and the necessity for implementing dolomite/francolite separations.

Jan 1, 1999

By D. B. Gentzler, J. L. Kohler

A method of monitoring production information (raw tonnage and machine state) from each working section has been developed. The method is based on the sensing of electrical parameters in each section load center, and the reporting of this information through the existing mine-wide monitoring system. A decision-theoretic type of pattern classification technique has been used to define the machine states. The basis of the method is presented in this paper, along with a proposed hardware and software implementation scheme. Information issues central to the development and use of the proposed production monitoring system are also discussed.

Jan 1, 1990

By R. D. MacDonald

The papers presented in this chapter cover a wide range of hydrometallurgical topics and might be considered to be unrelated to each other. All of the authors, however, utilized the basic methods of process mineralogy to characterize the reactants in their experiments and the products produced. The wide range of research topics which can be pursued successfully by the use of the methods of process mineralogy is a matter of interest in itself. One might speculate that the methods could be even more widely applied if only their utility were better recognized. These methods for characterizing reactants and products include principally x-ray diffraction, optical micros-copy, wet chemical analyses, instrumental chemical analyses, high intensity magnetic separation, micro-scale gravity separation, differential thermal analysis, micro-hardness testing, and judicious use of the sledgehammer and cold chisel. It is perhaps not by coincidence that most of the papers in this chapter were prepared not by mineralogists, but by hydrometallurgists, who are recognizing the importance of thinking in terms of mineral phases, and not just assays! It appears that the gap between process mineralogy and the mineral industry is closing, and that future AIME sessions promise to become established forums where mutual discussion of such topics as metallurgical "troubleshooting" and process design may become commonplace between plant engineer and process mineralogist.

Jan 1, 1981

By Ooms M, Scott OJ

This paper is concerned with the design and operation of storage and discharge facilit- ies for bulk solids handling. It presents an overview of the basic design philisophy emphas- ising the influence of bulk solid flow propert- ies and bin geometry on the flow patterns developed and how these, in turn, affect the reclaim efficiency and the bin structural in- tegrity and wear characteristics of both bins and chutes. The salient aspects of feeder design and operation will be discussed and the need to consider feeders as integral parts of the bin discharge system will be stressed.

Jan 1, 1978

By Dimitrios C. Konstantakos

Cofferdam excavations have traditionally been designed with classical design methods that involve direct computations of active or apparent earth pressures. However in contrast to finite element methods, traditional analyses can not account for full soil-structure interaction. Because of their complexity, numerical analyses are performed almost exclusively by computers. Recent theoretical and computer advancements have made the use of the finite element method much more user-friendly and affordable. General information about the basics of the finite element method in geotechnical engineering and for cofferdam excavations is presented. While knowledge of all intricate theoretical and computational details is not needed, the designer should at a minimum be aware of the most important aspects of soil modeling. Most importantly, the designer must have sufficient experience to be able to judge the relative ?correctness? of vast numerical results produced by today?s software programs. Hence, the human factor is an irreplaceable component of finite element computations.

Jan 1, 2013

By Ira E. Sproat

The question "Why can not American kaolins be substituted for English china clay?" has been asked time and time again, and more often since the beginning of the present war in Europe, which has threatened to cut off the supply of European clays imported from abroad. The answer to this question has invariably been, that the domestic kaolins are not as pure and uniform in composition as the imported clays. This demand for white-burning American clays is of such economic importance that it was considered advisable to determine whether some of our vast deposits of impure white clays could not be refined sufficiently to permit their being substituted for the foreign materials. Up to the present time mechanical principles only have been applied in the refining of kaolins, but in order to keep pace with the increasing requirements for better quality and uniformity of product, the application of the principles of colloidal chemistry is necessary. The investigation described in this report was carried on to deter- mine the practicability of applying technical control of clay disperse systems to the refining of kaolins and the utilization of the prepared clay in the manufacture of vitreous china and wall tile. It is hoped that this report will prove a stimulus to the clay- washing industry; will point out a method of refining certain Amer- ican clays, and will lead to the substitution of domestic kaolins for imported china clays by manufacturers of high-grade ceramic wares.

Jan 1, 1916

By Waghorne E. P

The State Electricity Commission of Victoria is Australia's largest single coal producer. Approximately 19 Mt of coal will be produced in 1989 from the SEC V's newest mine, Loy Yang Open Cut (LYOC), which com- menced overburden stripping operation in October 1982. When the adja- cent Loy Yang Power Station is completed in the late 1990's, LYOC will supply between 35 to 45 Mt/a, depending on power station performance and demand of coal for non-power generation uses. LYOC has been a major challenge for the SECV. It is the biggest single open pit coal mining development undertaken in Australia, with a whole of life capital cost approaching A$1 billion. The mine has supplied a very rapidly growing demand for coal from the expanding power station while developing in breadth, length and depth. Coal demand has consistently been above the figures anticipated during the initial planning because of the substantially improved performance of the 500 MW units of the Loy Yang A Power Station. The superior performance of the LYOC and power station has generated additional electrical energy during the first 5 years of power station operation compared with the initial planning targets- at almost no additional capital cost. This has been a major benefit to the SECV. LYOC will continue to present major challenges for the SECV, particularly in achieving overburden removal and coal reserve targets as development of the open cut continues to full depth over the next 15 years.

Jan 1, 1989