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By Sparrow G. J

In a recently completed AMIRA project, 20 samples were searched for gold mineralisation using the automated location facility (ALF) for rare phases on a scanning electron microscope in the CSIRO Division of Mineral Products, Melbourne. The samples were submitted by mining companies in Australia, and Papua New Guinea, and included crushed ore samples, cyclone overflow and underflow products, a flotation concentrate, and 12 tailing samples. Their gold contents ranged from 600 to 0.2 g/t An. Native gold and gold minerals including a gold telluride, gold-silver tellurides, and a gold bismuth mineral, were located in the samples as free grains and associated with other minerals such as pyrite, magnetite, hematite, ankerite, copper sulphides, silicate minerals, and quartz. In the highest grade samples, both micron sized and 200 ¦m grains of gold were found with ALF. It would be difficult to locate such d wide size range of gold in a manual search. Gold mineralisation was located in the tailing samples assaying 0.4 g/t An and higher. In several tailing samples coarse grains of native gold over 40 p.m in size were located. One grain was estimated to have contributed 40 per cent of the gold in the sample. As well as locating gold mineralisation, the ALF examination resulted in the identification of uranium, mercury, and bismuth minerals in the samples. Knowledge of the distribution of these minerals in processing streams could be important in the operation of a concentrator.

Jan 1, 1992

A description of:1. Air-lock at No. 14 Upcast shaft.2. Pit-top gates at Dudley winding shaft.3. Safety rider employed in sinking No. 18 shaft.1. AIR-LOCK AT No. 14 SHAFT.Some time ago it became desirable to raise and lower the McBride tunnel men to save them walking the inclined tunnel, about a mile in length, with a dip of nearly 600 ft., and a maximum gradient of 1 in 4. The main Upcast shaft, No. 14, was, therefore, equipped for winding the men. As this shaft was the main ventilating shaft for the McBride tunnel mine, it was necessary to take the greatest precautions against leakage of air. The writer therefore devised the concrete structure shown in Plate 1.The structure, as shown, surrounds the shaft inside the poppet legs. As the men are wound on double-decked cages (twelve men to each deck) provision is made at both top and bottom for the two decks to be loaded and emptied simultaneously. The doorsover the sky shaft, shown in the drawing, have been cut out and the sky shaft has been close-timbered with a double layer of T. and G. flooring boards, with building paper between, nearly up to the thimble frame, a small hole only being left for the winding rope topass through. The space between the ramps is glazed with plate glass to allow the winding-engine driver a good view of the pit top.The men are wound from two levels, 302 ft. and 611 ft.2. PIT-TOP GATES AT DUDLEY WINDING SHAFTTo minimise the shock to cage, couplings and rope when winding quickly, the writer devised the apparatus and arrangement shown in Plate n.

Jan 1, 1928

By A Sellgren, M R. Carstens, R Visintainer

There is a wide variety of industrial pastes or non-settling slurries pumped in mining, dredging and reclamation projects as products, refuse and tails. The types and/or names of some of the common ones are alumina red mud, phosphate clays, tar sands mature fine tails, tar sands (CT) consolidated clays and fly ash. The pipeline performance or friction of these varies dramatically with the type, its concentration and the particulars of the actual slurry making it difficult to select pumping equipment and to design associated pipelines. The GIW Hydraulic Laboratory in Grovetown Georgia has tested a number of these slurries over the last 30 years for various mining customers. Where available in the public domain and/or where permission has been obtained, the results of those tests are presented in this paper in a form usable for pipeline and pump system designers and users.

Jan 1, 2005

By P J. Colbert, P D. Munro

OZ Minerals' Prominent Hill copper-gold concentrator in South Australia was built in 2008 with commercial production commencing in early 2009. In addition to recovery of valuable minerals, the flow sheet for this iron oxide-hosted copper-gold deposit has to address the issue of producing a good quality saleable copper concentrate by high selectivity against non-sulfide gangue. Detailed mineralogical studies integrated with the metallurgical test work highlighted that liberation of fluorine-bearing minerals and subsequent very efficient rejection in cleaner flotation was necessary to produce a commercial quality copper-gold concentrate. Bench scale laboratory metallurgical tests and mineralogical studies identified the need to regrind rougher concentrate to a P80 of 20 -25 microns or finer for adequate liberation of the fluorine-bearing minerals. Satisfactory separation of the fluorine-rich gangue material from the valuable copper sulfides requires highly efficient cleaner flotation. This is done by a combination of washed froth cleaning and conventional dilution cleaning. Proven equipment developed to meet similar taxing liberation and separation duties for the treatment of the refractory zinc-lead-silver ores of the Carpentaria-Mount Isa Mineral Province have been selected. The combination of Xstrata Technology's IsaMillÖ and Jameson Cell technologies addressed both the liberation and separation issues in the Prominent Hill concentrator. The energy efficient IsaMillÖ technology both regrinds the rougher concentrate while its inert grinding environment prevents contamination of mineral surfaces with 'debris' ensuring subsequent optimum flotation performance. Heading up the cleaner circuit with a 'scalping' Jameson Cell followed by conventional flotation equipment allows this section to take advantage of the Jameson Cell's high intensity flotation environment and froth washing capability to achieve maximum concentrate grade (at minimum fluorine levels) while maximising recovery through the use of conventional flotation machines. This paper looks at the development of the Prominent Hill flow sheet from the initial mineralogical and laboratory test work to the design, scale-up and early operation of the Prominent Hill regrind and cleaner flotation circuits. The mineralogically-based approach of domaining metallurgical ore types combined with the axiom of size-by-size mineral particle behaviour by liberation class gave a clear understanding of the liberation and separation issues involved in the processing of Prominent Hill ore. Technologies developed to meet much more onerous liberation and separation duties for the treatment of the refractory zinc-lead-silver ores of the Carpentaria-Mount Isa Mineral Province were successfully used to improve concentrate quality by rejecting non-sulfide gangue containing impurities. An IsaMillÖ and a Jameson Cell are included in the circuit for fine grinding and for additional concentrate cleaning. Plant performance since commissioning has justified the approach for metallurgical test work and equipment choices for the flotation circuit.

Jan 1, 2009

By M Eichorn

Running a successful reagent plant trial is not an easy task, especially when trying to achieve an incremental improvement in a highly variable process, such as flotation. Cytec aims to achieve one per cent recovery improvement with 90 per cent statistical confidence. Most concentrators experience large fluctuations in recovery and so the æmagicalÆ one per cent is difficult to detect. With the aid of statistical software, including REFDISTR (proprietary) and ECHIPR, Cytec have developed a unique approach to differentiate between daily operational variation and actual process improvement. This paper describes how Cytec runs a plant trial based on extensive laboratory investigation and detailed analysis of historical plant data using statistical techniques.

Jan 1, 2000

Geochemical investigations carried out in the Woodcutters area, Rum Jungle district, NT., consisted of a programme of C-horizon soil geochemical sampling followed by rotary-percussion and diamond drilling.Comparison of detailed geochemical sampling with the original broadly-spaced sampling showed that the structures along which the orebodies occur are reflected very closely by the detailed sampling.A series of vertical rotary-percussion drill holes put down adjacent to a gossan revealed a broad layered dispersion of lead and zinc in the deep lateritic weathering profile, while primary dispersion haloes are only very narrow. The layering appears to be related to the weathering profile.

Jan 1, 1978

This paper details a proposal for integrating the use of the Pilbara Iron Ore Classification (PIOC) and stratigraphic data for fine tuning blast. pattern design on Mt Whaleback. The main thrust of the proposal is based on the assertion from Haqan and Harries (1979) that rock properties influence blasting results more than explosive properties. This premise is supported by a literature search, which indicated that blasthole burden, spacing, stemming and subdepth lengths are also determined by rock properties if the same explosive and blasthole diameters are used. A brief explanation of the PIOC is provided during which it is noted that the classification is based on physical hardness, mineralogical and genetic characteristics of the ore. The classification also extends to the two main waste rock types LBIF (banded iron-formation) and shale]. Ore type plans produced from face mapping indicate that many areas on Mt Whaleback can be divided into various PIOC zones and regions thus making it more useful in blast pattern design. Several recommendations for blast pattern design experimentation are made for hard, medium and soft ores as well as for the waste rocks, the most important being the use of expanded patterns to blast. soft BIF and medium hard to soft shales.

Jan 1, 1986

By P Cundall

Three-dimensional DEM (Distinct Element Method) simulations were conducted in order to examine the performance of screw conveyors, which are installed to transport bulk materials as parts of many industrial machines, including mining and construction machinery. To apply the DEM to the analysis of screw conveyors, we added a spiral object and cylinder objects, which correspond to the helical screw, the casing pipe, and the driving shaft of a screw conveyor. These objects are represented analytically to enhance the precision and efficiency when calculating the interaction between objects and particles. Simulations were conducted for some real applications: inclined and other types of screws, as well as the basic types (horizontal and vertical). Results were compared with previous work and empirical equations. It is concluded that this method is sufficiently well-developed and useful to analyse various kinds of screw conveyors.

Jan 1, 2000

A blast is designed to completely break competent rock such that it can be economically extracted, and efficiently handled or processed. Efficient breakage of the rock is critical to the success of an operation, and in many operations blast design is optimised to achieve fragmentation, muckpile profiles, and material that is easily excavated. There are inevitably other issues, such as damage to adjacent rock, that should be taken into account when designing a blast to achieve overall optimisation. Some of the key issues with respect to the integrity of the in situ materials adjacent to a blast are identified and briefly discussed in this paper. The potential for damage and the effects of a blast will be strongly influenced by the rock mass properties. This makes it important that site specific conditions and their response to blasting are known. Practical techniques that allow the disturbance adjacent to a blast to be measured with minimum disturbance to operations are described in the paper. Experience shows that, during the blasting process, there is considerable potential to disturb the in situ rock mass adjacent to the blast. In some circumstances a very important objective must be to minimise disturbance outside of the immediate blast area. Measured and observed disturbances caused by blasting to adjacent rock, for various common types of blasting, are discussed in this paper. Blast induced disturbances to the rock mass have been observed in both the near and far fields. These disturbances have the potential to impact on geotechnical design. The geotechnical significance of blast disturbance on a rock mass that is to remain in situ is explored and suggestions with respect to design are given.

Jan 1, 2004

In-pit crushing systems have been known in the mining industry for many decades. The question whether in-pit crushing is a viable option has often been asked. More than 200 mobile and semi mobile crushing systems have been installed worldwide at various locations and applications. Economic pressures have forced mine operators to reconsider the use of a conventional truck-shovel operation and have contributed enormously to the development of in-pit crushing and conveying systems. The in-pit crushing concepts have varying mobility capabilities. These range from fixed, stationary crushing plants to semi-mobile and fully mobile crushing plants. All these systems are operated in connection with a conveying system. In general in-pit crushing systems have technical and economical cost advantages over truck-shovel operation, particularly as mine capacities increase and mines become deeper. The integration of an in-pit crushing system represents a significant up-front capital investment and the mine is only able to depreciate the capital investment over a sufficient mine life including plant capacity to realise the benefit of the much lower operating cost.

Jan 1, 2003

By H Zahiri

Utilisation of the InSAR technique for monitoring of subsidence in mining areas, employing open pit and underground mining methods, has large potential due to sensitivity and safety issues associated with usage of the classical surveying techniques. InSAR can also be very competitive concerning the cost of provided results. However, there are a few issues that may significantly limit InSAR applicability for subsidence monitoring in mining areas. The altered terrain topography, involving steep slopes and deep pits, may lead to the layover of radar signal for specific satellite and pit geometry. Also, the highly dynamic character of subsidence induced by mining, especially using mass mining methods, may lead to issues such as apparent heave and ambiguous results. In this paper the authors analyse the above-mentioned issues and demonstrate how InSAR technology was applied, as a supporting system, to monitor large scale and highly dynamic subsidence for a real case study in Western Australia.

Jan 1, 2008

By S R. Grano, J Duan, T A, D Fornasiero

We have determined the experimental rate constants for chalcopyrite particles floated from a complex sulfide ore and compared them with those calculated using a recently developed flotation model. The model incorporates contributions from the efficiencies of collision, attachment and stability between particles and bubbles, as well as their frequency of collision. For these calculations, the contact angle of the chalcopyrite particles in the ore was obtained independently using a surface spectroscopic approach. The calculated flotation rate constants were in good agreement with the experimental data and able to reproduce the characteristic maximum in flotation rate constant for particles of intermediate size. The values of bubble velocity and turbulent dissipation energy derived from these calculations are relatively low and may well correspond to mean values of these parameters inside the flotation cell. We have extended this approach through the application of a property based model to an operating plant, with a satisfactory outcome.

Jan 1, 2005

By A B. Bell

The health and in some cases survival of mineral exploration and mining companies is, in today's markets, more dependant than ever on the effective use of information technology. The need for speedy collection, organisation, maintenance and distribution of corporate and project information is a phenomenon that will continue to strengthen with market thirst.Geographic Information Systems (GIS) provide a medium for storage, maintenance and retrieval of data, and Internet Mapping adds a technology for effective distribution of that data. Combining these technologies can return benefits both fiscally and technically by reducing costs of ownership in IT infrastructure and increasing the efficiency and effectiveness of both internal and external information delivery.GIS and Internet Mapping technologies have reached a practical stanza in their evolution and will continue to develop as a key business tool in the natural resources sector.

Jan 1, 2002

The efficient development and exploitation of an orebody relies on an understanding of the mineral characteristics of the deposit. This information is valuable throughout the mining cycle - during exploration, assessment, testing, design, operation and rehabilitation. Problems can arise at each stage if there is an inadequate appreciation of the mineralogy involved and its effects on the treatment process. Modern image analysis systems now permit a more quantitative understanding of the mineralogy of an ore to be gathered. Where previously the metallurgist had to rely on qualitative information to guide technical decisions, it is now possible to give numerical estimates to the compositional and textural properties which govern the mineral concentration processes. Ore samples can be characterised according to modal abundances, mineral grain size parameters and mineral associations, all of which affect the liberation and concentration of the values. The paper will discuss the application of quantitative process mineralogy by considering a number of case studies. These include: ore characterisation to assist in exploration, assessment and mine planning; modal analysis of complex mineral suites to assist in the evaluation of ores, the deportment of values between products and the recovery or loss of these values; liberation analysis for ore testing, plant optimisation and performance monitoring; and characterisation of tailing to guide estimates of leachability, stability and rehabilitation options.

Jan 1, 1998

By G Davies, D Dunn, C Mawdesley, O Bertoli

The coal industry in Australia has been actively working in recent years towards the (re)integration of geostatistical techniques to the process of coal resource estimation. The benefits of using geostatistical techniques, over the current interpolation algorithms in use in coal modelling packages used to generate the grid estimates, need to be illustrated for the methodology to gain a broader acceptance in the coal industry. This paper focuses on the benefits gained at BHP Billiton Mitsubishi AllianceÆs Saraji mine for the estimation of the total product yield value at a 9.7 per cent product ash cut-off of a particular seam of the Saraji deposit. In order to perform this comparison, the results of the alternative estimation methodologies need to be benchmarked, which in most situations is achieved through the reconciliation of the estimates against production and/or process plant reconciliation data. Unfortunately, this benchmarking was not possible as no reconciliation data for the area of interest in the chosen seam was available, as it has not been mined at the time of the study. Where no reconciliation data is available, an alternative method is to use conditional simulations as the benchmark for comparison. The simulated values can be regarded as ærealityÆ, and the alternative estimation methodologies, based on a sampling of the underlying ærealityÆ, can then be compared using the simulated ærealityÆ as the benchmark for comparison.

Jan 1, 2009

ICI Australia has been developing PC-based software to assist the blast engineer to design and monitor open pit blasts. The scope of this software differs significantly from commercially available mine design packages.The software is designed for routine use in a normal production environment. The system enables the engineer to produce practical documents which include: a drilling plan, a loading sheet, a hook-up diagram, an inventory of explosives and auxiliary items, and other data on the blast such as tonnages and powder factors.

Jan 1, 1992

There are two main areas of application of geology in quarrying: (i) In regional planning for industrial mineral requirements.(ii) In direct quarry management. The regional planning requirement has recently become more evident because of greatly increased land demand conflicts around cities. The direct quarry involvement is a reflection of both the economy and the greatly increased sophistication of the quarry industry. Here, professional planning and development expertise by a geologist is required, to ensure continued supply of raw materials at the best price to the consumer with sufficient profit to the producer. Today, geological insurance safeguards capital investment in plant and assures economical development plans.

Jan 1, 1978

The Filblast Cyanidation Process incorporating intense high shear mixing, high gas mass transfer efficiency and high oxygen concentrations under conditions of elevated pressure has now been been successfully applied in gold cyanidation mills since May 1993. The first commercial unit had a slurry capacity of 110 cubic metres per hour. Since then 230 and 450 cubic metre per hour units have been installed and a 1000 cubic metre per hour unit has been designed. Laboratory and pilot plant Filblasts have also been built.The reactor is a robust, compact in-line or end-of-line device and may be constructed out of a wide range of materials including wear and corrosion resistant alloys and ceramics. The Filblast Process may be applied to high temperature leaching of refractory gold ores and base metal concentrates.

Jan 1, 1997

An understanding of the importance of the different components that comprise a rock bolt unit is necessary to ensure the proper use of rock bolts as a means of roof support. The various anchors, bolts and plates in use in Australia have been designed and adapted for Australian con- ditions. As mining conditions change, so will the types of bolts in use. This is apparent in the development of chemical anchors and other recent innovations.

Jan 1, 1971

To grow a mining company today is seen to be challenged by the reduced interest in resources companies by the financial markets, the complexity of native title and a somewhat depressed commodity cycle. However, the opportunity to grow production and sales in a mining company are as numerous as they have ever been. It is the challenge of growing significant shareholder value that is difficult. The distinction between growth in æcompany sizeÆ and growth in æshareholder valueÆ is an important distinction upon which some resource companies are now firmly focussed. The equity market/commodity market cycle can provide windows of opportunity to consolidate and expand a company for the benefit of shareholders. These benefits may not be reflected until more buoyant equity markets return but, as the cycle turns, as it surely will, those with the foresight to position themselves may be richly rewarded.

Jan 1, 2000