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"The Australasian Joint Ore Reserves Committee (JORC), which is sponsored by the Australian mining industry and its professional organisations, developed the JORC Code to provide minimum standards for public reporting. JORC was first published in 1989 and later incorporated into the Listing Rules of the Australian and New Zealand Stock Exchanges making compliance mandatory for listing public companies in Australia and New Zealand."

Jan 1, 2003

By F. E. Lathe

The method of feeding blast-furnaces to be described below is simply the application of well-known principles, and an attempt to carry that application to its logical conclusion. It does not involve radical changes in equipment, nor does it require unusual skill on the part of the furnaceman. In fact, much of its value lies in its very simplicity. Before giving details of the method it will be well to consider briefly the conditions under which it was used at the Nickelton plant of the British America Nickel Corporation, in the Sudbury district, before that plant closed down. The Sudbury nickel ore consists chiefly of pentlandite, chalcopyrite and pyrrhotite in a gangue of norite or greenstone. The proportions of sulphide and gangue vary widely in different mines, the former constituting about 45 per cent of the total in the British America sorted ore. The gangue is fairly uniform in analysis, carrying about 55 per cent Si02, 18 per cent A120 3, 13 per cent FeO and smaller quantities of CaO, MgO, Na20 and K20. The ore has been frequently described as refractory, a word which seems suitable when one considers the many unsuccessful attempts to smelt it pyritically, as well as the high percentage of coke normally used at all the plants in the district.

Jan 1, 1925

By C. O. Swanson

THE purpose of this paper is to discuss the use of the dip needle in the field of mining geology. The subject matter is new only to the extent that it reflects the writer' s added experience in recent years. The treatment is brief, and those interested in a more extended analysis are referred to the articles listed at the end of the paper. In the discovery and tracing of mineral deposits, the clip needle, like most other geophysical instruments, can be used in two ways. One method may be termed direct; the other, indirect. The direct method is that of finding or following certain ore-bodies by virtue of their magnetic properties. Explicitly, or by inference, it is the method which many mining men and practising geophysicists have in mind when they consider whether or not a certain property should be studied by geophysical means. In the ideal case, this method demands little or no knowledge of geological conditions. The indirect method uses the clip needle as an aid to purely geological studies in working out the structure of a mineralized area. Although not as simple as the direct method, it enjoys a much wider field of usefulness. The writer's experience in the past fifteen years, which is believed to be typical, is that the indirect method finds application four or five times as often as the direct method. The indirect method is of particular value because it furnishes information concerning the relationship between geological structure and ore occurrence. Most mining engineers will agree that structural control is an important factor in the localization of ore deposits, and therefore that the subject under consideration is of some interest in mining geology. Specifically, then, the present purpose is to outline the principles and practice of using the clip needle in working? out geological structure.

Jan 1, 1941

By M. Nejati, A. Paluszny, R. W. Zimmerman

A numerical method is proposed to propagate multiple discrete fractures leading to primary fragmentation in a mine that is being worked using block caving. Deformation is computed using the finite element method, fractures are represented explicitly, and the mine domain is discretized by an unstructured mesh. Bedding planes are represented by systematically varying the elastic modulus of the rock and by defining horizontal weakness planes. Fractures and matrix are represented using parametric surfaces, and tips are defined by their boundary curves. Tip advance is controlled by a failure criterion, and a criterion for propagation direction and magnitude, based on the evaluation of the modal stress intensity factors. A novel domain integral approach is applied to accurately compute stress intensity factors (K) ahead of fracture tips in three dimensions. The method does not require a structured volumetric mesh structure around the crack tip, as integration is performed over a series of virtual surface domains along the crack front. The method is efficient, as it makes direct use of automatically generated, arbitrary tetrahedral meshes, and approximates stress intensity factors (KI, KII, KIII) along each crack front using Interaction-integrals. As opposed to the JIntegral, the method does not decompose K a-posteriori, but instead uses an auxiliary field to directly compute modal K. When using this method, numerical approximations of K do not exhibit dependence on the mesh layout, and require meshes that can generally be ten times coarser than are required by displacement- and stress-based methods. Volumetric meshing requires only, on average, 17% of each computation step. Thus, cracks do not follow any pre-existing mesh structure, and the method is well suited for high-density fracture datasets. The method is demonstrated for primary fragmentation of a mine area covering 110 initial draw points, immediately beneath a 2m high undercut. Displacement is constrained at all boundaries except the surface of the undercut. The growth of the fractures is investigated at the onset of the undercut. Ninety initial disc-shaped fractures are taken into account, each having an initial radius of 10 m. Fractures grow around the undercut, intersect the bedding plane boundaries, and the domain is fragmented as a result.

Jan 1, 2015

By L. Rosato

In the past decade, as a result of increasing iron loads, Canadian Electrolytic Zinc (CEZinc) has become a pioneer in understanding the critical factors that affect the roasting of concentrates with high pyrite contents as well as those factors governing the effects of high iron loads on the leaching circuit. De-bottlenecking efforts in the roaster and acid plant section of CEZinc have given rise to a better appreciation of the impact of iron on roaster productivity. High standards for impure solution quality, zinc recoveries and residue disposal have all led to an increased comprehension of the limits of the leaching circuit and the optimization potentials with respect to iron and ferrites. In this paper, the impact of iron on the roasting and leaching circuits of CEZinc will be reviewed and special emphasis will be given to some of the more recent process optimization and improvement activities.

Jan 1, 2006

By N. N. Rulyov

"Starting from fundamental principles of colloid-hydrodynamic theory of disperse systems we have shown that application of strongly non-uniform hydrodynamic fields allows to achieve not only faster rates of flocculation of suspension, but also supports significant improvements in the quality of clarified water and separation characteristics of solid phase. Specifically, it has been experimentally proven that the new treatment method based on these principles (then termed as ""ultra-flocculation"") allows:•,Increase the output of thickeners and pressure filters by 1,5-1,7 times;•,Decrease solids fall through into the filtrate in the process of vacuum filtration by 2¬3,5 times;•,Improve the rate of purification of water phase in the upright thickener by 1,5-1,9 times;•,Decrease flocculant consumption by 1,5-3 times;•,Increase the effective operational life time of cloth filters by 3-4 times;•,Ensure sustainable operation of separation equipment, i.e. decrease the sensitivity of process to variation in suspension concentration, as well as to variations of suspension composition and dispersion characteristics;•,Apply flocculant solutions of concentration 2-3 times higher, thus increasing the capacity of equipment used for solutions preparation."

Jan 1, 2004

By I. Demers

The abandoned Manitou mine site covers an area of approximately 190 ha near Val d?Or, Quebec. This old site has been generating acid mine drainage for several decades. In 2006, a partnership was established between the Quebec Ministry of Ressources Naturelles (MRN) and Agnico-Eagle Mines to reclaim the Manitou site using tailings from the nearby Goldex mine. These neutral tailings were to be deposited on top of the Manitou site. An extensive study was performed to evaluate specific reclamation scenarios to control acid mine drainage using Goldex tailings as cover material. The article first describes the global approach used for this evaluation, which includes in-situ hydrogeological monitoring, tailings characterization, laboratory column tests, and numerical modelling. Of the thirteen column tests, three were conducted to evaluate the parameters affecting the performance of covers made of Goldex tailings placed over the spillage area of the Manitou site. Geochemical and hydrogeological parameters were assessed during the leaching column tests for almost two years. The tests aimed at evaluating the effect of water table level and monolayer cover thickness on the overall performance. The testing procedure involved monthly leaching and measurement of geochemical parameters. Results indicate that water table position is the most important factor affecting the monolayer cover performance to control AMD. Based on these results, it was established that the water table must be located near the interface between the Goldex and Manitou tailings to effectively reduce AMD generation. Cover thickness also has an impact on cover performance, which is however less significant than the water table position. The testing scenario with a water table located at the interface with a one-meter Goldex tailings cover showed progressive improvement in effluent quality.

Aug 1, 2013

By J. M. Belland

This paper deals with the geology of the Smallwood mine in relation to its influence on mining and milling operations. Structure within the orebody, and variations in ore grade and material types, will be described and associated with the various drilling, blasting and milling operations. The orientation of planes of weakness, either bedding or jointing planes, and contacts between extremes in material types influence the size of the broken material. Generally speaking, variations in grinding rates and recovery can be associated with stratigraphic sequence and metamorphism.

Jan 1, 1966

By A. D. Walters

"IntroductionScreens are used in coal preparation plants for four basic functions, namely:I. Scalping off large size run-of-mine coal for initial size reduction;2. Sizing of coal treatment in different process streams;3. Removal of magnetite (dense medium) from clean coal and refuse;4. Dewatering.Canadian coal preparation plants use screens extensively in the above functions. Even plants where no beneficiation takes place, screening and crushing are carried out in the size reduction process.Description of Process UnitsThe type of screen used in coal preparation plants generally falls into the following categories:Fixed Screens and Grizzlies (for large coal)Often a simple rugged construction, either set horizontally above a bin or inclined with the coal flow.Fixed Sieves (for fine coal)They are used for dewatering and/ or size separation of slurried coal or discard. The sieve bend, the Vor-Siv, the Wilmot riffle and the cross flow screen fall into this category. The most commonly used in coal preparation plants is the sieve bend, Figure 1. Coal slurry is fed tangentially onto a fixed curve wedge wire screen deck. The solids are separated at a predetermined particle size, delivering a partially dewatered overproduct and a dilute underflow. The coal slurry is initially delivered to the sieve bend via a feed box. A series of baffles spreads the feed evenly across the width of the deck. The slurry drops from the last baffle, passes through the feed spout and is fed tangentially to the screen. It is important that the feed should contact the surface immediately at the front end of the sieve bend. It is possible to lose as much as 250Jo of screening area with a poorly fitted screen box.The full stream of coal slurry flowing over the sieve bend decreases in depth, in increments of approximately •;4 the slot width each time it passes a slot. Sieve bends make a size separation at 112 to 2h the slot width. This feature virtually eliminates blinding of the screen surface. Slot sizes are normally quoted in millimetres, available standard slot sizes are from 2 mm to 0.125 mm. The sieve bend is also widely used in coal preparation for preliminary dewatering."

Jan 1, 1989

By O. Espinoza Ortega, S. Song

A process scheme has been devised to improve the silver recovery and the grade of concentrates from the scavenger concentrate of a silver ore flotation circuit. Based on modal analysis studies it was found that silver sulfide minerals in the scavenger concentrate were associated as simple binary particles and finely disseminated in sulfide and non-sulfide gangues. Fine grinding of the concentrate improved the grade-recovery curve of silver to a very limited extent owing to heterocoagulation between liberated fine silver sulfides and coarse particles of gangue. This heterocoagulation phenomenon was prevented by grinding the concentrate in the presence of the dispersing reagent sodium hexametaphosphate. The silver grade-recovery curve was improved by practicing. before the conventional flotation step, a selective aggregation step for the fine silver sulfide particles using the non-polar oil kerosene, the sulthydryl collector Aerophine 3418 and conditioning the pulp under strong agitation conditions.

Jan 1, 2004

By H. Scott Swinden

"ForewordA symposium on base metal deposits was held in Bathurst, New Brunswick, from June 10-13, 1990, sponsored jointly by the Geological Surveys Branch of the New Brunswick Department of Natural Resources and Energy, the New Brunswick Prospectors and Developers Association, and the Geology Division of the Canadian Institute of Mining, Metallurgy and Petroleum . Papers prepared for the symposuim are being published as a series of articles in the CIM Bulletin. This second paper (the first was by Fyffe, et al., in Vol. 83, No. 938) in the series presents an overview of the paleotectonic settings of massive sulphide deposits in the Dunnage Zone of Newfoundland with emphasis on volcanic geochemistry.ABSTRACTCambrian and Ordovician volcanic sequences of central Newfoundland, which record the history of the Iapetus Ocean, are prolific hosts to volcanogenic massive sulphide (VMS) deposits. Geochemical, isotopic and geochronological studies show that the vestiges of Iapetus in Newfoundland probably record a complex series of island arcs and back-arc basins that were marginal to, rather than part of, the main ocean basin of Iapetus. The geochemical and isotopic data provide a means of characterizing the tectonic environment of individual volcanic sequences, and allow us to identify a number of distinct tectonic environments in which VMS depositiontook place.Four tectonic environments have been identified as being associated with VMS deposition: (I) back-arc environments hosting VMS deposits include both N-MORB-type ophiolites (e.g. Skidder?) and volcanic sequences with oceanic island (or within plate) tholeiite characteristics (e.g. Great Burnt Lake); (2) primitive arc environments include both supra-subduction zone (SSZ) ophiolites (e.g. Betts Cove, Rambler) and volcanic/epiclastic sequences (e.g. Point Leamington, Duck Pond) and are characterized by abundant arc tholeiites, with lesser refractory lavas and rhyolites; (3) mature arc environments comprise dominantly thick felsic and mafic volcanic piles in the Buchans - Robert's Arm Belt (including the Buchans camp) and are characterized by dominantly calc alkalic basalt and andesite; and (4) continental rift environments occur in the Hermitage Flexure area (e.g. Strickland deposit) and are characterized by dominantly felsic volcanic sequences.Island arc environments are by far the most prolific hosts to VMS deposits. Patterns of VMS distribution in central Newfoundland show that similar tectonic settings may be recorded by very different stratigraphic sequences (e.g. both ophiolites and thick volcanic/ epiclastic sequences may record primitive arc rifting) and emphasize the importance of the rifting in VMS generation, irrespective of the details of the tectonic or stratigraphic setting. The ability to judge the prospectiveness of a volcanic sequence by using whole rock geochemistry to evaluate its tectonic environment may prove useful in area selection at the grassroots exploration level."

Jan 1, 1991

By Magnus Evertsson, Johannes Quist

HPGRs have since introduced in the 1980s (Kellerwessel, 1993; Schönert, 1988), now become integral comminution units at several minerals processing plants around the world. Even though a lot of the initial issues concerning performance, availability and wear have been addressed and solved there are still phenomena and aspects which can be improved and understood further. Schönert and Sander (2002) presented experimental results and a mechanistic model including the internal force dynamics between the rollers and the compacted bed. They derived expressions for the pressure distribution involving most of the influencing terms and effects. However, in order to solve the differential equations several of the terms vanish by assumptions. The Schönert and Sander model reflects the experimental data in many aspects but the predicted shear force distinctly deviates from the experimental results at the angular position of the peak pressure level. This finding suggests that the particle to particle interaction and breakage process in the different zones seen in Figure 1 are complex and difficult to model using analytical models. A numerical modelling approach using DEM does not require the same amount of assumptions and simplifications of boundary conditions. Hence such modelling may provide further knowledge and vital understanding. In this paper the breakage process is simulated in order to investigate the shear slip behaviour and how it relates to different operating variables. A laboratory scale HPGR corresponding to the experimental setup used by Schönert (2002) have been modelled in EDEM (DEM-Solutions). The bonded particle model (BPM) is used for modelling quartz particles (Potyondy, 2004). The breakage model strength parameters are calibrated against interparticle breakage experiments in an Instron 400RD compression device. The contact model parameters are calibrated using calibration methods developed by Quist (2015). The floating roller dynamics are modelled using a spring-damper system. Results present insights regarding the interparticle slip behaviour as well as the frictional tangential force distribution on the rollers. The simulated roller pressure distribution shows good correspondence with previously reported findings in the literature.

Jan 1, 2016

By P. A. Bahri, D. G. Dixon, T. M. Woodward

A comprehensive mathematical model of the Sherritt-Gordon ammoniacal pressure leaching process at K winana Nickel Refinery has been constructed. The process is comprised of six autoclaves functioning as a three-stage leach circuit, operating over the temperature and pressure ranges of 85-95°C and 750-1000 kPa, respectively. The process chemistry forms a complex series-parallel reaction network, characterised by: (1) the gas-liquid mass transfer and reduction of oxygen, (2) the oxidation of eight distinct minerals, (3) the oxidation of sulphur, and successive reactions involving various intermediately oxidised sulphur species, and (4) the oxidation of Fe(II) to Fe(III), and subsequent precipitation as a hydrated ferric oxide. Material balances were developed for species in all three phases, and an energy balance to account for all reactions and phase conversions. The multiple convolution integral (MCI) statistical reactor model was employed for the scale-up of particle kinetics. The model has been validated against plant data, and simulation results are in agreement with plant performance.

Jan 1, 2005

By M. Moats, J. A. Gonzalez

A review of operating practices in zinc electrowinning plants is presented in this paper. Surveys were sent to several zinc electrowinning plants and data provided by some of these plants was compiled in a database. Information about anodes and cathodes, electrolyte composition, stripping methods, cells, electrical systems, and additives was compiled and analyzed. From the data analysis, correlations between operating variables are presented. Recent trends in operational practices are also highlighted.

Jan 1, 2008

By B. A. McKee, T. Adamcewicz

For a capital expenditure of only $46,000, Caland Ore Company has successfully converted its three dry grinding center peripheral discharge rod mills to dry grinding ball mills. The conversion has resulted in a significant capacity increase, operating cost reductions and in-plant environmental improvements. This paper describes why and how• the conversion was made.

Jan 1, 1972

By M. Kreuh

An investigation of the pressure pulse spectrum generated by the gas dispersion processes in a Peirce Smith copper converter was undertaken via the simultaneous measurement of four tuyeres using high frequency pressure transducers. The data was captured, stored, and analyzed using digital data processing techniques; including power spectral density plots, band-pass filtering, and a principal component analysis (PCA). The process was characterized throughout by a dominant 3 Hz pulse signature attributed to the formation of lateral gas envelopes. In particular, test tuyeres in the tuyere line tended to operate synchronously at the dominant frequency, regardless of operating conditions tested and despite being distributed along the converter. Synchronous behavior is thought to arise from the acoustic coupling and possible resonance behavior of the gas delivery system on the converter.

Jan 1, 2007

By Muhammad Zaka Emad

ABSTRACT: Sublevel stoping mining methods with delayed backfill employs cemented rockfill (CRF) as a backfill material. It is used in underground mines to achieve ground control and reduce wall slough. In addition CRF serves to reduce development waste and provides a working surface for mining the upper levels. Efforts to optimize CRF practices have been published. This paper presents a detailed review of CRF practices in open stoping mining systems with reference to case studies. A new methodology is suggested in a simple stepwise approach, which can be adopted for site specific conditions. The need of laboratory testing and quality control program is discussed based on the published literature.

May 1, 2013

By Tweedy. D. H.

"The paper describes the rapid development of, and operational experience in the utilization of, pneumatic low-pressure pipeline hoisting systems to vertically convey raw coal and rock through shafts, supplementing shaft capacity-the greatest lift to date being 535 m.A typical installation has raised over 250,000 tonnes in less than one year from a depth of 413 m through a 350/ 400-mm pipeline at a rate of 85 tonnes per hour. Operational experience on seven systems has provided valuable data on performance and operating costs.The main advantages of the systems lie in the flexibility of the pipeline to occupy existing free space in shafts and underground roadways, the relatively low first cost, the short delivery and installation time, and the economical running cost.Conclusions are therefore reached on future applications for example, the use of boreholes in older mines where new production technology has outstripped shaft or slope capacity, inter-level hoisting to implement concentration on transport roads and perhaps full mine output from relatively small mines.IntroductionIt is seven years since the basic art and practice of the pneumatic hoisting of minerals was described. The technique was developed in Western Canada by Radmark Engineering and found favour in the United Kingdom with the National Coal Board. Engineering and commercial feasibility trails were conducted in collaboration with the Mining Department and Mining Research and Development Establishment of the N.C.B. There was also considerable involvement with the British Health and Safety Executive.During the last five years, rapid progress has been made in the installation of new systems in the United Kingdom, Hungary and other countries. The operational experience gained makes it possible to report ""in depth"" on these installations, which cover a wide range of different physical mining applications."

Jan 1, 1982

By R. G. Rosehart, S. Y. Lee

"The current investigation concerns the removal of arsenic from waste waters using ion-exchange resin and activated carbon as sorption media. Use of certain weak and strong base anion exchange resins permits the removal of arsenic. Arsenic may be loaded on the weak base resin in the pH range of 2 to 3 and on the strong base resin above pH 5. The elution of arsenic is successfully achieved using 0.5 M NaCl or a mixture of NaCl and NaOH. The activated carbon investigated was less effective on loading arsenic, but the arsenic loaded was easily eluted by simple pH adjustments."

Jan 1, 1972

By Erik C. Westman

Knowledge of the orientation and relative magnitude of in-situ stresses at the mine scale is important for safe and efficient production from an underground mine. With this knowledge, stope location and scheduling can be optimized. Passive seismic tomography was used for imaging horizontal stress distribution at the mine scale. Microseismic measurements from the Creighton mine were used as input for the tomography calculations. The double-difference tomography algorithm was used, which provides the most precise results. The results clearly show a low velocity zone in the previously mined areas bounded by two high-velocity lobes located adjacent to the mined openings at locations consistent with those expected due to the horizontal stresses at the mine. The overarching goal of the research is to provide a tool that can augment both numerical modeling results and underground geotechnical measurements to allow the mine operator to produce in the safest and most efficient manner possible.

Jun 1, 2012