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By B. Tanda

A process has been developed at Curtin University whereby glycine is used in an alkaline environment to leach gold, silver and copper from their ores, concentrates, process intermediates and wastes. Copper mineralisation investigated includes various oxides, sulfides and native copper. The leach process utilises an oxidising environment such as oxygen. Glycine is a non-toxic, non-volatile, edible, low cost reagent which is produced in large industrial quantities for use in several industries. Glycine and its copper and precious metals complexes are stable over wide pH, Eh and temperature ranges. Other than losses in leach residues, the glycine is recovered and recycled for leaching. Iron dissolution is insignificant in the pregnant leach solution. Iron in pyrite remains unaffected, whereas iron associated with base metal sulfides (e.g. chalcopyrite and bornite) is converted to a readily filterable iron hydroxide. Efficient separation of copper by solvent extraction and conventional electrowinning has been shown to be feasible for a number of organic extractants, whereas gold and silver glycinates adsorb very well onto carbon allowing CIP/CIL/CIC (carbon-in-column) based processes. The process is ideal for ores containing acid-consuming gangue, concentrates with high arsenic or halide contents and for copper-gold ores with significant sulfide mineralisation. The process eliminates many of the problems associated with the processing of copper-gold-silver ores, such as elemental sulfur formation, silica gels, unwanted metal co-dissolution, and jarosite precipitation. The reagents used and process residues are much safer and environmentally benign than conventional process options. The processing technology can be applied to in-situ, heap and vat, or agitated tank leaching at temperatures ranging from ambient to below 100?C at atmospheric pressure and is currently being commercialised. This paper will focus on copper leaching and recovery and iron rejection from a chalcopyrite flotation concentrate.

Jan 1, 2016

THE ore treated is almost pure copper pyrites (chalcopyrite) in a gangue of quartz and quartz-felsite. Very little free iron sulphide (pyrite) occurs, and at the time of the erection of the flotation plant the stopes in the oxidized zone had been almostentirely depleted. This zone only extends to a shallow depth, and, below the l00-ft. level, the sulphide for the most part is clean and bright but in the crushed and brecciated parts of the ore channel, where surface water has circulated freely, the gangue is decomposed and kaolinized, and the copper sulphide badly tarnished. This class of ore gave considerable trouble at the mill, but unfortunately, was very limited in quantity. A sample of rich ore assayed-Copper, 21.2 %; iron, 24:.3 %; silica, 28.9 %; sulphur, 25.1%.The concentration in the original mill was effected by handpicking, jigging, and tabling. A considerable portion of the copper mineral arrives at the surface in the form of large lumps of very pure quality, eminently suitable for sorting out by hand.The rich ore is tipped over a grizzly at the shaft bins; the oversize hand-picked, and the undersize bagged direct.

Jan 1, 1912

By Priyadharshini M. R., Premalatha K

"Abstract With the development in the construction of heavily loaded structures, the necessity of pile foundations has increased. For the transfer of heavy loads, it is mandatory that the piles need to be socketed in the underlying rock strata. The load transfer in bored rock socketed piles is by end resistance or the combination of shaft and end resistance which in turn depends on the length of the rock socket. The determination of socketing length of the pile at present is mostly based on a few factors which affect the pile load transfer mechanism. The effect of all the possible factors involved, need to be studied in proposing guidelines for the design of rock socketing length of the pile. Analyses are carried out using finite element analysis software (PLAXIS 3D Foundation) to understand the influence of the thickness of overlying strata for different socket lengths of piles in weak rock. From the load settlement curves, the influence of the overlying soil on the rock socket length isobserved and an effective rock socket length is proposed.IntroductionThe determination of socketing length of the pile at present is mostly based on a few factors affecting the pile load transfer mechanism, which sometimes give a better design and sometimes an uneconomical design. Too much socketing length results in more construction time and higher costs. Therefore, the effect of all possible factors involved need to be studied in proposing guidelinesfor the design of t h e r o c k socket length of the pile.The factors that affect the termination criteria of the rock socketed pile are the capacity requirement, thickness and properties of the overlying soil, characteristics of the founding strata, drilling tools used, roughness of the rock socket and nature of loading.A comprehensive study was performed to understand all the above mentioned factors in different types of rocks. In this paper discussion is made on the settlement results, specifically the influence of overlying sand of different densities above a weak rock. The influence of stress developed is not discussed, keeping in mind the size of the paper under study."

Jan 1, 2014

By C. B. Manula, R. L. Sanford, R. A. Rivell

Part I. DATA INPUT ALTERNATIVE 1

Jan 1, 1974

By C. J. Sullivan

It is of importance, in prospecting, to distinguish ores of magmatic origin from those derived by the meta-morphism and granitization of source rocks and from those accumulated in certain sedimentary facies. The magmatic ores, which are characterized by their occurrence along fault structures, may be associated with volcanic (including explosive) phenomena. Heat effects are local. The magmatic sequence is well de-fined: kimberlite, with diamond pipes; ijolite, with carbonatites; peridotite, with nickel deposits; norite, with nickel-copper deposits; and diabase-gabbro, with copper-zinc deposits. These deposits are characteristic of Precambrian shields, where a thick sialic crust may rest on basic to ultrabasic magma. The sequence is resumed in the Paleozoic terrains (in a broad sense), with monzonite porphyries and associated copper, copper-gold, and cop-per-lead-zinc deposits.

Jan 1, 1962

By R. V. Ramani, R. Bhaskar

The results of an experimental and theoretical research study into the spatial and temporal behavior of dust in mine airways is summarized. Experiments were performed in mine airways under both controlled and normal operating conditions. The controlled experiments included the documentation of the concentration and deposition patterns for two types of dust under three different velocities. Real-time dust concentration data were obtained using real-time aero- sol monitors (RAM-I) to determine the dispersion coefficient in a mine airway. On the theoretical font, a convection diffusion model of the dust flow phenomenon in mine airways was developed considering dominant mechanisms affecting dust transport and deposition in mine airways. Mechanisms modeled include turbulent and gravitational deposition, coagulation, and dispersion. In this paper, comparative analyses of results (8 the controlled experiments with the predictions of the mathematical model are presented. In addition to the overall validity, the adequacy of the individual components of the model, such as deposition in the total and respirable range, and dispersion are examined in light of the experimental observations. The experimental data from controlled experiments compared more favorably with model predicted results for similar conditions as opposed to the comparative analysis results for in-mine experiments. Specifically, the model predictions for an 800-m stretch of a mine airway reveal some significant differences from the behavior noticed in the mine. The deposition was lower than that predicted by the model. Consequently, concentrations were higher than those predicted by the model. The implications of these and other findings for further investigations are discussed in the paper.

Jan 1, 1987

By M. W. Grabinsky, M. S. Diederichs, E. Hoek

Provided that they are used correctly, numerical models can be of considerable assistance to mining engineers in designing underground excavations. Guidance is given to the engineer or geologist who is not a specialist in numerical analysis but who is interested in using numerical modelling tools or in employing someone to analyse the stresses, displacements and failure in the rock surrounding underground excavations. A description of the theoretical background to a number of these numerical models and discussion of the advantages and disadvantages of each are followed by guidelines on the selection of appropriate models for each stage in the development of a mine, from exploration to the completion of mining

Jan 1, 1991

By W. J. Kingwell

My comments and questions are addressed to Mr. Troughton. It seems to me that the tests were very well tailored to determine long term effects on performance of bearing piles as groundwater pressures rise in the London Basin. This rise is being simulated by means of a groundwater recharge system but it would be informative to have further details of the controls of conditions simulated. Ideally the porewater pressure in Standpipes 1, 2 and 3 should be the same throughout the test. Under test conditions are there not practical dif­ficulties? Recharge Well C2 is a lesser dis­tance from the pile than the other wells. Was the rate of recharge to C2 regulated to a lesser rate than the other three? In my experience the rate of acceptance usually varies from well to well. Under a common feed pressure were mea­sures taken to compensate for this? Since the problem does not only affect London, but also Liverpool, Nottingham, Birmingham and to a lesser extent, Manchester, I question whether an ideal procedure is being used. It is well known that rates of acceptance decrease with time and often recharge wells need to be flushed out at regular intervals. Other pro­cedures may need to be adopted to accurately simulate the effect of groundwater rise, if tests of longer duration are to be considered.

Jan 1, 1991

By Paul Kents

The Canadian Javelin Limited Cerro Colorado copper-porphyry deposit in Panama, possibly the largest known copper-porphyry, contains between 1350 and 450 meter elevations, drill proven and probable ore in excess of 3.0 billion tons averaging 0.65% of copper equivalent. The deposit is located in the Central Cordillera Range, straddling the Continental Divide at 1500 meter elevation. Local topography is very steep. Accessibility is difficult, all logistics made by helicopter, and only recently a 52 km. road from the Pan-American highway was completed into the area. The deposit was discovered in 1969, and since then 75 shallow exploratory holes and 98 deep holes, the deepest 1340 meters, totalling 45,000 meters have been drilled. Deep holes were drilled at the corners of a regular rectangular 150 meter grid.

Jan 1, 1975

By L. S. Beck

"IntroductionThe Beaverlodge District is an important mineralogenic province of pitchblende and occupies about 1300 square kilometres centred on Beaverlodge Lake near the north shore of Lake Athabasca in northwest Saskatchewan (Fig. 1). Uranium City is the main settlement of the area and is serviced by scheduled aircraft from Edmonton, some 700 km to the southwest, and from Prince Albert which lies a similar distance to the south.During the summer, boats and barges supply the area from the railhead to Fort McMurray via the Athabasca River and Lake Athabasca, a distance of about 550 km. For the past few years a winter road has been maintained across Lake Athabasca to Cluff Lake to connect with Highway 155.The topography of the area is typical of the Precambrian Shield with generally low relief and a disorganized drainage of numerous lakes separated by hummocky rock ridges, muskeg and drift-covered areas. Local topography in the area is, however, extremely rugged, particularly south and east of Beaverlodge Lake, where resistant rocks form prominent hills and ridges extending as much as 180 m above lake level. Rock exposures are abundant and form over 50 per cent of the land area.History of Exploration and DevelopmentEconomic interest was first aroused by Tyrrell (1896) who described an occurrence of iron formation at Fish Hook Bay; however, subsequent evaluation of the deposit indicated it to be uneconomic."

Jan 1, 1986

The Illawarra District, from 50 to 100 miles south of Sydney, is one of the State's important coalfields. It extends from Clifton on the north, to the Shoalhaven river on the south, and from the coast westward beyond the coastal scarp.For descriptive purposes, this area falls naturally into two zones:(a) the coastal belt backed-by the eastern edge of the plateau;(b) the plateau, westerly from the coastal scarp.(a) The Coastal Belt.A triangular shaped area extending from Clifton to the Shoalhaven river, composed for the most part of soft coal measures strata of Permian age, which, on weathering, undermines the massive overlying Mesozoic sandstones and causes the gradual recession of thecliffs.South of Wollongong, upper marine sediments and contemporaneous igneous rocks make their appearance beneath the coal measure beds and occupy the greater portion of the coastal belt.(b) Plateau Area.Extending westerly from the coastal escarpment is a plateau known as the Robertson Tableland, composed of Triassic sandstone and shales dipping gently in a northerly direction, and capped in places by Wianamatta. shales and r.rertiary basalts. This tableland is approximately 2400 feet above sea level in the vicinity of Robertson, and gradually falls to about 750 feet at Waterfall.The plateau area for the most part is highly dissected, rough, steep gorges alternate with sharp ridges.A large part of the northern watershed of the Robertson tableland is a reserve for Sydney water supply, and large dams have been constructed at Cataract, Avon, Burke, and Cordeaux.

Jan 1, 1938

By Johan F. W. Kock

"Hearing loss due to excessive noise exposure is the most prevalent industrial disease. It is ranked on the World Health Organization’s (WHO) priority list for major work related injuries. Uncontrolled noise not only has a physical effect, but is also a psychological hazard affecting the performance and well being of man. Noise induced hearing loss (NIHL) is irreversible, yet it is preventable. The first defence against noise (noise control engineering) is a high priority in the mining industry. Second defences should be a last resort when the engineering control of noise is inadequate. Hearing conservation programs and the use of conventional hearing protection devices seem to have failed in the prevention of noise induced hearing loss. If compensation payouts that quadrupled in the past ten years are used as a barometer for the success of existing hearing conservation programs, then new strategies and technologies need to be investigated. The best practice Hearing Protection Device (HPD) may be seen as the minimum standard for second defence noise control.Conventional hearing protection is widely applied, but also misused in the industry as well as in the mining sector. Empirical research results, ownership, general attitudes of workers as well as qualitative aspects will be explored. The paper provides reasons, evidence, case studies and strategies regarding the best practice hearing protection philosophy (the Noise Clipper Model) as implemented in the Implats Mining Group. Worldwide tendencies towards custom-made HPD’s, findings that indicate improvements in hearing conservation programs and finally the successful application of Custom-made Hearing Protection Devices, will be outlined."

Jan 1, 2003

The West Coast region of the South Island is situated astride the Pacific û Australian plate boundary zone. The most significant component of this zone is the Alpine Fault. A variety of reconstructions of the pre-Alpine Fault plate tectonic configuration of the New Zealand continental area have been attempted over the past 25 years or so. Most of these have not been closely constrained by a regional compilation of field data related to the age and horizontal displacement history of the Alpine Fault. A model in which the Alpine Fault was initiated no earlier than the interval 18 - 16.5 Ma (B.P.) is proposed, a significantly younger age of inception than has been widely accepted as the onset of dextral displacement along the plate boundary through the South Island. A subsequent history of displacement is presented consistent with the West Coast basin stratigraphy. The alluvial gold content of some parts of the Miocene to Pleistocene conglomerate sequences is also discussed.

Jan 1, 1996

By P. Jacquin

Many a deposit estimation has been carried out since geostatistical methods were first implemented. To date however few mining programs have totally been completed and even fewer comparisons can be drawn between estimated reserves and extracted ore tonnages. Aluminium Pechiney work a number of bauxite mines in Southern France. As from 1969 they modified their deposit estimation methods, giving up traditional approaches and opting for geostatistics. At that time, the authors of this paper were entrusted with the first geostatistical estimations and in particular, those concerning the deposits mentioned herein. Over the past decade a number of deposits have been worked out and we thought it interesting to report about comparative results. French bauxite deposits are of the karstic, as opposed to the lateritic, type. The bauxite, formed at some distance of the present-day deposit, was brought to and trapped in limestone karst pits. Subsequent physical and chemical alterations may have taken place : silica and carbonate drifts, recent karst slips. The morphology of these deposits is often rather complicated. The deposits are small from a few hundred thousand to a few million tons at the most. The overburden thickness usually precludes open mining. Mining investments and financial risks are often high, making it necessary to obtain optimal information on the deposit considered for mining. For the three cases brought up in this paper, deposit sizes, exploration methods and conclusions differ. They are brought up mainly to show the advantages inherent to a quality geostatistical study and the lessons drawn by Aluminium Pechiney.

Jan 1, 1982

By D. Olsen

The paper discusses the legislative and practical approach adopted to problems of management of environment in relation to coal mining in a very sensitive area of the south coast of New South Wales. The environmental problems are complicated in this area due to multiple and very often conflicting land usages. The environmental approach in relation to water quality maintenance, noise control and air quality is discussed and methods adopted meet stringent requirements. Requirements of New South Wales Regulations on Environmental Impact Statements (EIS) are described.

Jan 1, 1988

By Williams K. C

This paper presents a brief account of the plant which has been developed at Port Pirie to recover, by vacuum distillation, the greater part of the zinc content of desilverized lead. The present plant is an experimental unit, which is run in conjunction with the normal refinery practice, but can be cut out of the circuit. It will shortly be dismantled and duplicate units will be built on the sites chosen for the final plant installation.The unit described here has treated flows of 16 to 37 tons per hour of desilverized lead, to recover 90 to 95 per cent of the zinc contained in it. It is not intended here to detail all aspects of the vacuum dezincing operation, nor the developments which precededthe adoption of this design. The essential features of the present plant will be described and, where these are peculiar to the present experimental location, the intended alteration for the final plant will also be mentioned. OUTLINE OF PLANT AND PROCESSLead issues from the continuous desilverizing kettle at about 350° C. containing about 0·57 per cent Zn. It is conveyed by a tiled launder to the preheater, where it is heated to 580-620° C.Hot lead from the preheater enters the vacuum vessel via a barometric leg. From a reservoir holding about 19 tons of lead it falls by gravity in a thin film exposed to high vacuum (20-50 microns)3 and leaves the vessel via a barometric leg, entering the lead pot. The lead leaves this pot at 540-560° C., containing 0·03 to 0·06 per cent Zn, which is removed, together with residual antimony of 0.02 to 0·06 per cent, by a separate final refining process.

Jan 1, 1956

By Harold J. Miller

Loading and haulage of run-of-mine ore is frequently the highest cost in underground mining operations. These costs can be significantly reduced by use of belt conveyors, a common practice in coal and similar soft miner ii mines. This is particularly true if oversize ore and rock can he eliminated prior to conveying; thus producing a demand for crushers near the production areas. Portable feeder-breakers are extensively used in conveyorized mines, but no suitable, equivalent equipment, is available to provide these benefits to hard rock mines of low to medium headroom. A hard rock crusher capable of easy movement and readily disassembled would allow use to belt conveyors and could improve the general safety and productivity of any underground ore hauling system. This report summarizes proposals and findings made in conjunction with the newly designed M-44 Low Head Portable Crusher which is believed well capable of meeting the requirements of a "portable, underground, hard rock" machine as previously defined in earlier reports. Data gathered by use of the 1/4 Scale Model of the M-44 has substantiated and verified the concept sufficiently to justify construction of a full-size machine for further testing under actual mine conditions.

Jan 1, 1978

By R. Vogt, H. C. Mult, F. L. Wilke

INTRODUCTION At present, the capability of production planning software based on Linear Programming (LP) is still limited to the optimization of the single LP-run. This is due to the LP-model itself which cannot consider the interdependencies between individual LP- runs. With regard to planning of selective mining this limited way of optimization frequently leads to situations, where the remaining and accessible ore blocks do no longer allow to produce ROM-ore in the qualitative composition required by the ore processing plant. However, many of the aspects taken into consideration when setting up production plans built from mutually dependent LP-runs cannot be modelled in a system of linear equations. They are thus unsuited for treatment with LP and have to be taken care of by the planning engineer without any assistance by the system. The KBS currently under development is intended to assist the planning engineer in designing a production plan under special consideration of the combination of consecutive LP-runs and blending beds. It is not necessarily intended to find the optimum solution within a given planning situation which is, anyway, hard to determine due to the multitude of influences. The objective is rather to work out a good and - from the practical point of view - feasible production plan. The new aspect with respect to mine planning is the integration of expert knowledge and experiences via the KBS into the planning process in order to support the planning engineer. The planning system is being developed in close cooperation with an iron-ore open pit mine. COMPONENTS OF THE PLANNING SYSTEM The software is being developed on a workstation under UNIX and comprises the components LP, CAD-module and the KBS. The applied multi-goal LP-algorithm is an in-house development of the Department of Mining Engineering at Technical University Berlin. It was already successfully implemented within other mine planning programmes and was only slightly adapted to the specific needs of the present system. Within individual LP- runs it finds the optimum qualitative composition of ore production in the sense of the selected optimizing criterion and under the given restrictions: i.e. it determines tonnages to be mined from blocks in order to optimally meet the requirements of the ore pro- cessing plant. A CAD-module based on the commercial SURPAC package in combination with a simulation device is used to graphically depict the block model and progress of mining. Both LP-algorithm and CAD-package are integrated in the KBS. It has been decided to use the shell NEXPERT OBJECT as it is a hybrid system which supports both rule-based and object-oriented knowledge representation. MINE-MODEL AND LP-MODEL KBS have to be tailor-made for specific planning problems. Therefore, it had to be decided which specifications of the iron-ore mine should be represented in the model. As the limited possibilities of a university institute do not allow to develop a KBS for mine planning which is ready to use in industry, it was decided to concentrate on those characteristics that can be regarded as typical for iron-ore surface mines and that seemed to be suited for treatment with knowledge-based techniques. The following chapter summarizes the most important features of the mine model. The description of the requirements to the mine's sales products is followed by an outline of the applied LP-model. Mine model • The model of the mine as it is used for planning consists of • the block model of the deposit, • the mobile equipment, • stockpiles and blending bed and • the requirements to the sales products. The deposit is described by a block model which contains data on the chemical composition, LOI, grain size and tonnages. Grain size was included as it is important for the two sales products of the mine. Furthermore, it is known whichs blocks require and which don't require blasting; this is relevant to the assignment of loading equipment to individual blocks. The blocks are devided in three categories: • ore, which will directly be taken to the blending bed; • waste, which will be put on the waste dump; and • blocks which will be either transported to the blending bed, to stockpiles or to the waste dump depending on the specific planning situation. This decision is made during planning. Neighboring blocks are combined in mining areas to which the loading equipment is individually assigned. Mobile equipment comprises shovels and wheel-loaders as well as trucks. The characteristics of the loading equipment are important for their ability to load different blocks and for the permissible degree of their re-positioning etc. The mine disposes of a blending bed for homogenization of the production, of a waste dump, and of several stockpiles with different ore qualities. The requirement to make only limited use of the stockpiles for economic reasons is included in the KBS. According to long term planning two commercial products have to be produced, which differ both in grain size and qualitative composition (TABLE 1). Their mass-proportions in the blending bed have to be within a fixed range. Not considered in long term planning is the occasional need for lump ore, which occurs at very short notice and has to be produced in a "campaign-like" manner. This requires the total re-arrangement of all plans for on- coming blending beds and would therefore be ideally suited for

Jan 1, 1996

By J. Menuge, G. Barker

"Liberation (QEM-SCAN) and surface chemical (time of flight secondary ion mass spectrometry -ToF-SIMS) analyses have been undertaken on plant Pb circuit flotation samples with the aim of defining the factors resulting in sub-optimal recovery. Lead flotation circuit feed, cleaner concentrate and tails samples were examined on a size-by-size basis using QEM-SCAN. Sulfide minerals accounted for approximately one third of the flotation feed with pyrite making up 16 wt.%, followed by sphalerite (13 wt.%) and galena (3 wt.%). Non-sulfide gangue minerals comprised calcium carbonates calcite (26 wt.%), dolomite (14 wt.%) with quartz, feldspars and barite all contributing > 5 wt.%. QEM-SCAN analysis indicated that liberation was not the primary cause of the poor flotation response. Principal component analysis was applied to the ToF-SIMS data derived from five samples (as for QEM-SCAN plus rougher concentrate and tails) to enable identification of correlated surface chemical components. Although a significant range of correlations were observed we focus here on those that show a discernible pattern throughout the float circuit. It was found that for the flotation feed the surface of galena were largely obscured but where Pb was observed there was a strong correlation to surface Fe. For the rougher and cleaner concentrates the galena surfaces were relatively clean with no correlation to Fe for the rougher concentrate and minor correlation in the cleaner concentrate. However, in the rougher and cleaner tails the clear correlation of galena with Fe was again apparent. These results suggest, in combination with prior studies of pyrite morphology, that the principal factor effecting grade is the rapid oxidation of the framboidal pyrite resulting in the contamination of the galena surface with a high loading of hydrophilic oxidised Fe species, thus depressing flotation."

Jan 1, 2014

By Henry A. Gordon

Under the title " Hysteromorphous" it is proposed to include deposits which have been formed from original deposits by the influences of the surface-region. The term Hysteromorphous—later-formed—has been used by Prof. Posepny, of Vienna, to distinguish secondary from primary deposits and is more comprehensively applicable than the terms or designations hitherto used for the same thing.

Jan 1, 1896