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This paper reviews the role of fill in mining including consolidated fill both histor- ically and currently as determined by a recent survey of the Fill Subcommittee of the Canadian Advisory Committee on Rock Mechanics (CACRM). It covers the application of fill in modern min- ing methods including mechanized cut and fill, undercut and fill, post pillar cut and fill and longhole pillar recovery between stabilized fill. An automated fill preparation plant and recent developments in rotary drilling of hydraulic fill conducting holes are described briefly. The paper also summarizes the findings of some of the important laboratory and field work carried out on the behaviour of fill in Canada, the United States and Australia and again draws on current information obtained from the Fill Subcommittee of the CACRM. Space limitations and unavailability of suitable material prohi- bit the summary of similar information from other countries.

Jan 1, 1973

As partition curves are widely employed to characterize screening efficiency which, by definition, should include a time parameter, it is shown, perhaps for the first time, that time is already included in the partition curves and how. Laboratory and plant results are used to show how screening efficiency depends on feed composition, near-mesh and oversize material and screen motion, and how these factors may combine to give an erroneous result that two identically efficient screens are different and two screens of different efficiency are identical. Reasons are given which show why a renewed interest in screening would benefit not only screen engineers and operators but also those concerned in formulating standard specifications of screen analysis methods.

Jan 1, 1984

By Woodcock JT

This paper reviews the chemistry of flotation pulps with the aim of gaining a better understanding of the effect of chemical environment in flotation and ap- plying the knowledge to improving the con- trol of reagent additions. Theories of flotation are considered briefly, but they are only of limited help in specifying an appropriate chemical environment and in establishing control techniques. The chemical nature of flotation pulps is reviewed. Four distinct phases are present - solids, an aqueous liquor con- taining many dissolved reactive sub- stances, organic liquids, and gases. All of these vary in many ways and interact with each other. It has now been estab- lished that there are many previously- unsuspected materials present in plant pulps that can or might affect flotation. Concentration profiles of selected para- meters in operating plants are given to show some typical changes that occur. Recent advances in collector chemistry, especially that of xanthate and related species, are reviewed. Modes of decompo- sition and/or formation in pulps of xan- thate, dixanthogen, perxanthate, xanthyl thiosulphate, and monothiocarbonate are reviewed, and their W absorption spectra are compared. Some relevant information on dithiophosphates, mercaptobenzothia- zole, and thionocarbamate is summarized, and some speculative comments are made about reactions of these collectors.

Jan 1, 1984

Shear strength testing of rock discontinuity surfaces has been undertaken at a considerable number of open pit gold mining operations in Western Australia, as part of geotechnical studies of pit wall stability. These mining operations are located in geological settings that are typified by highly weathered and/or chemically altered rocks that contain significant structural fabric in which accurate and representative measurement of shear strength is essential.Little of the published rock discontinuity shear test work and back-analysis of failures has been conducted on weathered discontinuity surfaces, at low normal stress levels which are comparable to Western Australian conditions. Available shear strength data are reviewed and the following aspects of shear strength testing are considered:ò the need for shear strength test work and the amount of testing required;ò review of laboratory testing methods and the quality of the results; ò presentation of the test results;ò discussion of the shear strength failure criteria; ò interpretation of the test results;ò summary of test results for a variety of rock types, degree of weathering and discontinuity surface conditions;ò a review of laboratory and field shear strength data to illustrate the amount of variability that can occur; andò a monitoring strategy is proposed to manage the uncertainty associated with discontinuity shear strength.

Jan 1, 1992

Over the past 15 years, Artificial Intelligence (AI) techniques have shown promise of providing the ability to capture `human intelligence' into a computer program. The sub-fields of Expert Systems and Artificial Neural Networks are finding increased use in industry to perform tasks previously considered the domain of human thinking. But, are these methods just a new type of software much like that of the past or is real magic hidden within the lines of code? Will this field continue to enjoy high growth rates and if so, what developments will we see in the near future? Which algorithms and methodologies will continue to grow? This paper discusses a number of paradigms which can be used to create successful applications. There are certain barriers; some psychological - some linked with knowledge acquisition, that must be overcome or avoided to ensure system performance. Development time also requires careful consideration before embarking on an Al project. The paper focusses on constructing goal-driven systems that transfer high-technology solutions from the research laboratory to the plant floor. Respect for system users is of paramount importance - whether their involvement is to access contained information or to participate in program maintenance as new knowledge becomes available. Examples of successful and unsuccessful AI implementation in Canadian industry and academia provide evidence of the importance of this issue. The paper also examines some current constraints on applying AI in the real-world. Among these problems are automated knowledge acquisition, methods to acquire data during run-time, real-time systems (hardware versus software), explanation and justification features and adaptive/leaning systems.

Jan 1, 1995

Wetherstones gold deposit is located just east of the township of Lawrence, in the Otago District of the South Island, New Zealand. The paper will describe aspects of the mining and exploration history of the Wetherstones gold field, current knowledge of the geology of the deposit, and speculate on possible outcomes of exploration in the modern era.   As at the famed Gabriels Gully situated nearby, most of the Wetherstones gold is/was contained in, or recycled into modern drainages from, the Blue Spur Conglomerate (æBSCÆ). The BSC is the basal member of a wedge of auriferous non-marine sediments of latest Cretaceous age which are tilted against the Tuapeka Fault Zone, a structure of regional dimensions. In particular mineralisation of elevated grade (which cannot yet be reliably estimated) appears to be concentrated in an elongate basement depression (ægutterÆ) of width around 100 m, variable thickness to a few metres, and axial length in excess of 500 m. The gutter plunges from the base of alluvial mining (where it has been partly exploited by underground methods) to depths of more than 100 m, beyond which it remains open and untested.   The prospects for a revival of mining at Wetherstones depend upon confirmation of what is here inferred to exist, and the discovery of additional gold. The economic prospects of the project however are enhanced by what is known or indicated of the geographic location, and anticipated geologic, mining and metallurgical characteristics of the mineralisation, and consequent anticipated environmental management issues.   The recognition of gold contained in pyrite in the BSC represents an upside to project economics which has never previously been evaluated. The Wetherstones Basin covers more than five square kilometres in areal extent. There is no modern exploration record of the majority of this area, leaving open the prospect of the discovery of additional gutters, and primary mineralisation in the underlying schist.   Australasia Gold Ltd has embarked on a program to reassess the potential resources of the Wetherstones gold mineralisation, and to evaluate the feasibility of mining.

Jan 1, 2004

By H Rouhullahi, E B. Veshki an, R Kottnauer

The Galandrud coalfield is located approximately 20 km south from the coast of the Caspian Sea, Ruyan town, on the north slopes of the Alborz mountain range, in the elevation between 500 m (the Galand River valley) and 1350 m. For the time being, 32 coal seams (generally of small thickness û 0.8 m on average) have been recognised within the. On the other hand 72 coal banks of balanced properties have been included in reserve calculation, which means that some of the seams consist of several banks. The general dip of strata belonging to the south limb is about 30¦ to the South (with drags close to the south overthrust, where the dip reaches 85¦), while the dip of beds at the north limb is rather steep and usually between 45 to 75¦ to the North. The coal quality is in a rank of high volatile bituminous coal. The steep dip, unstable lithological development, complicated tectonics and comparatively lower coal seam thickness are the characteristic features of the Galandrud deposit. Environmental protection of this area makes exploration and exploitation more complicated. During mine exploration several adits were driven at three levels with 50 m vertical distances. About 4000 m of gates and crosscuts were up to now driven. During mining test the down-cut mining method (with one cut), the strike cut mining method and the down-cut mining method with two cuts were tested. The paper describes outlines for the selection of mining methods on the base of classification of the effective hangingwalls and footwalls, hazards of mining operations, and possibilities of the mechanised mining.

Jan 1, 2003

By P Grouhel

In the recent years several new blasting technologies have come into use in surface mines. Electronic initiation, low-density emulsion explosives and modelling software are in regular use throughout the world. In Australia, these new technologies have achieved significant application, largely in open cut coal mines where more than 20 per cent of blasting is now conducted with electronic initiation systems. These new techniques have contributed to the vast improvement in blasting outcomes evidenced by increased recovery of saleable product and faster excavation rates. In large surface mines, OricaÆs unique combination of electronic initiation systems, bulk emulsion explosives and modelling software can be harnessed to target critical value outcomes. This includes targeting better fragmentation, increased ore uncovery rates and better wall stability û all adding to improved mining operation profitability. Orica Mining Services have combined these technologies into a set of offerings called Blast Based Services (BBSÖ). The paper describes applications of these new technologies and possible benefits in large surface mines.

Jan 1, 2007

By Bearman R. A, Parkin R. M

Traditional quality control procedures for aggregates production within the quarry industry rely on off-line laboratory analysis, resulting in poor performance and inconsistent product quality. A high speed on-line aggregate classification system is described here. A product sampling system directs aggregate through an inspection chamber where a novel imaging system digitises the particle geometry. Data processing algorithms extract dimensional data and image features, while a neural network classifier assigns a qualitative shape descriptor to each rock particle. This system provides each sampled batch with a complete analysis of size and shape distributions, complementing a new generation of cone crusher technology to maximise product quality and plant efficiency.

Jan 1, 1995

By Brathwaite RL

The gold-scheelite-quartz lodes of the Wakamarina valley were the most productive of the mesothermal gold-bear in the Marlborough Schist. Most of the production came from the Empire City and Golden Bar mines which worked tug, Golden Bar lode. Only 134 m of its 1800 m strike length are accessible, in the No. 2 level of the Golden Bar Mine. A fau I has downthrown the Golden Bar Mine section by 2 47 m and displaced it left-laterally by 18 m. The lode is a typical ribbon-banded mesothermal vein, averaging c. 1.75 m wide, and enclosing narrow horses of schist country rock. It i composed of bands of milky "buck" quartz with thin laminae of schist. Scheelite occurs in short strings of grains withi quartz on the footwall side of the lode and also in small quartz-carbonate veinlets in the foot wall and hanging wall schist The lode quartz contains only localised traces of pyrite and arsenopyrite. They are more abundant in the wall-rock schist.

Jan 1, 1995

The kinetics of desorption of nitrogen from molten iron were investigated using the electromagnetic levitation technique. The respective influences of gas flow rate and surface active element (S) were examined. A second order behaviour with respect to the nitrogen concentration in the melt prevailed at all experimental conditions. Sulphur had a marked inhibiting effect on the desorption rate. The experimental results on the rates of nitrogen desorption have been interpreted with the aid of a reaction mechanism consisting of a sequence of elementary steps.

Jan 1, 1991

Diamond drilling was first carried out at Norseman in the Princess Royal Mine, early in this century. Little concentl'ated drilling was done from then until Western Mining Corporation commenced drilling in 1934. Since then Central Norseman Gold Corporation N.L. has continually employed diamond drilling in exploration of the field. After 1946 the advantage was seen of applying broad pattern surface drilling at Norseman in the reef exploration. In 1953, as a result of the steeply rising cost of drilling and the time taken to penetrate surface material by light equipment, heavier drills and new rigs were introduced. The surface drilling programmes called for a greater monthly or annual footage and to satisfy this new techniques were introduced. The Mitchell-21 machines were discarded and A-3000 machines were installed, firstly under a 48 ft. fixed tower, then mounted on a truck with a 20 ft. tower, and finally on a truck carrying a 40 ft. tower. With the mobile units a compressed air compressor is attached. By use of compressed air with either the Reed roller or Hawthorne bit, rate of penetration of overburden is greatly increased. The mobility of the truck mounted machines has greatly reduced the time required to move from one hole to another, and the use of heavier machines on a three shift per day basis has considerably increased the footage per shift. The general result is an increase to 1,500 ft. of drilling per month per machine, while costs have been greatly reduced in spite of increased wages and diamond prices.The underground drilling technique is described. Analysis of performance has not been made because the drillers performance is subject to shaft routine and service.INTRODUCTIONGold was first discovered at Dundas in 1894, and at Norseman, 14 miles north, in 1895. From that tirpe until 1935 mining activity fluctuated. Following the mining revival in 1935, production in the field has remained comparatively stable. This stability in part has been due to the broader scale of operations of Central Norseman Gold Corporation N.L., and in these operations diamond drilling has played an increasingly important role.

Jan 1, 1956

By M Grossi, G Baiden

This paper describes a new mine backfill method based on a newly invented binder with several years of test results from laboratory and onsite applications. The new binder has several advantages over traditional Portland and slag cement binders. One tonne of the new binder can replace two to three tonne of Portland cement when used to consolidate backfill and can result in the same compressive strength within seven days. When comparing backfill slurries of the same pulp density, the new binder attains more volume of in-place backfill mass than Portland cement because of the high crystallisation of water, resulting in tightly filled stopes. The crystallisation of the water provides for less or no dewatering in the backfill stope and easier transportation of the backfill slurry. Pastefill performance can be achieved by using pulp densities typical of a hydraulic backfill and the new binder, all the while transporting with the same ease of hydraulic fill.

Jan 1, 1998

By Potter DJ, Firkin GR

The Imperial Smelting Furnace operated by Sulphide Corporation Pty. Limited at its Cockle Creek zinc-lead smelter was recently equipped with tuyeres angled at 25 degrees instead of the usual 10 degrees. This change was prompted by the results of model studies undertaken by tha Research Department of Imperial Smelting Processes Limited, at Avonmouth in the United Kingdom, and by the favourable results of operating trials on the Cockle Creek furnace using bent-tip tuyeres to simulate 25 degree inclination. The use of 25 degree angle tuyeres has made it possible to operate with lower zinc values in discard slag and has improved hearth stability over a wider range of sinter quality and composition.

Jan 1, 1981

This paper outlines the advances made in vacuum filtration as developed by Outomec Process Filters and details the results obtained at a number of Australian installations. The first section of the paper details the technical advances made by the use of ceramic media in vacuum filtration and explains the reasons for the use of the technology. The second part of the paper discusses a number of Australian installations of the ceramic vacuum filter and where possible compares the actual experiences with those predicted from the test work which preceded the installations. The Ceramec Capillary Vacuum Filter is a vacuum disc filter which combines the proven mechanical attributes of a disc filter with exciting new ceramic vacuum technology from Outomec of Finland.

Jan 1, 1991

By Hewitt D

A study of two laterite profiles developed on a serpentinite near Rockhampton, shows that loss of Si02 and MgO results in the relative concentration of Fe203, A1203 and a number of minor elements. Serpentine is broken down to form montmorillonite, goethite, quartz and kaolinite. Enrichment of nickel occurs, and it is shown that the element is mainly associated with montmorillonite and serpentine. Highest nickel values are associated with a zone in the profile which occurs at a depth of 10.5-22 metres, and the bulk of the nickel in this zone (42-80%) is associated with the

Jan 1, 1974

By Curless JM, Power SG

Polymetallic hydrothermal veins of the Western Cascades are hosted in propylitically altered Tertiary volcanics of calc-alkaline affinity and (or) in nearby, altered, and compositionally similar plutons. Ores from shallow and now abandoned mines produced mostly gold and were considered to be of epithermal origin. However, recent discovery of breccia and porphyry types of Cu-Mo mineralisation and other data suggest that the deposits of this terrane vary systematically both regionally, south to north, and locally, high to low altitudes. The evidence includes changes in (1) size, composition, and complexity of plutons, (2) types of mineral deposits; (3) assemblages of alteration and ore minerals; (4) trace metal geochemistry of host rocks; and (5) fluid inclusion and sulphur isotope data. They collectively imply a consanguineous origin of vein, breccia, and disseminated-veinlet types of mineralisation by magmatic hydrothermal processes.

Jan 1, 1987

By L Reynolds

The portable infrared mineral analyser (PIMA) was trialled to determine the extent and intensity of any hydrothermal alteration halo associated with gold mineralisation in the Hyde-Macraes Shear Zone (HMSZ) of the Otago Schist.   Twelve diamond drillholes through the HMSZ were analysed with the PIMA at a sample spacing of 1 m. The drillholes were selected on two traverses along the line of strike and down-dip of the mineralisation in and around Panel 2 of the Frasers underground development.   The study showed that the Hangingwall shear of the HMSZ has a more distinctive infrared signature in intersections with high grades. The Hangingwall shear in these drill holes is defined by a shift in the wavelength of the Al-OH absorption feature from ~2220 nm to <2210 nm. This shift is attributed to a change in the mineralogy from phengite to muscovite. Overprinting this trend in some of the drillholes is the presence of the 2210 nm Al-OH absorption feature, ascribed to kaolinite. Kaolinite also tends to be present in numerous other regions of the schist above the Hangingwall shear associated with steeply dipping faults and foliation parallel joints. In drill holes with low grades the Hangingwall shear does not exhibit any obvious infrared signature.   At the scale of study, the PIMA does not provide evidence for an alteration halo associated with hydrothermal mineralisation above the Hangingwall shear. Possible tectonic movement may have displaced any alteration halo that once existed, away from the zone of mineralisation. For this reason, PIMA apparently cannot be used for predicting the location of the Hangingwall shear during exploration drilling. However, the study did show that the PIMA could define the Hangingwall shear when the rocks were sufficiently altered and mineralised.

Jan 1, 2007

Magnetic separation using particle rotation in a continuously rotating magnetic field offers very low to insignificant non-magnetic particle entrapment, and precise magnetic fractions. The precision of rotating magnetic field separations makes the method ideal for dry laboratory magnetic analysis work, where conventional laboratory magnetic separators can give misleading or uncertain data. The very low entrapment characteristics make the method ideal for entrapment-critical separations within the diamond exploration industry or in gold recovery. A single wet rotating magnetic field (RMF) unit is able to achieve a cleaner separation (at similar or better recovery rates) than a three-stage separation using conventional wet drum separators. The RMF separator is able to work effectively at particle sizes below 50 ¦m, and RMF separation could, at least in theory, be used down to single domain particle sizes. Rotating magnetic field (RMF) separation is carried out by magnetically spinning the particles at frequencies up to 300 Hz. The particle rotation itself may be used to roll the particles out of the separator. At angular velocities of 100 Hz, magnetic flocs are unable to form, and any entrapped particles are energetically expelled. In an RMF separator, the outer drum can be stationary while the inner magnet rotor rotates, allowing, for example, the injection of cleaning water underneath the separating magnetics to help remove small suspended non-magnetic particles.

Jan 1, 2000

By C Fearon

This paper discusses the implementation of an underground rail haulage system during a major expansion of the Olympic Dam mine in 1998. The factors affecting the selection of rail haulage are discussed and details are provided on the rail system, which is designed to transport more than 10.5 million tonnes per annum (Mtpa). The reliability of the system during commissioning is discussed, including the decision to manufacture a ædummyÆ locomotive in order to keep the system operational. Finally, reliability improvements made both during and after commissioning are discussed with comments provided on the effectiveness of the system as it operates today.

Jan 1, 2005