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By Brien RT, O&apos

The work reported in this paper extends,-bhsb on the "Heat Hardening of Artificial Magnetite ;Pellets"., which was described at the- International Symposium on Agglomeration ;-sponsored by the American Institute. of Mining, Metallurgical and Petroleum Engineers at Philadelphia; U.S.A. in April, 1961. Whereas- that work was of a.,more basic nature, -serving to illustrate the suitability of artificialòmagnetites with various.admixtures, to the application of heat hardened pellets, on: this occasion the aim-is to illustrate the procedures-which were used-to- establish the dimensions of commercialòrecuperativ strands for Australian raw materials,The nature of the pellet feed, i.e. relatively uniform :spheres of4 3/8 in. - 7/16. in. diameter, makes it possible to use small scale static pots for test work. By the use of a closed system and the measurement of suctions, gas f lows, and temperatures through beds, the speed and heat requirements of the various stages of heat hardening can be measured, so: that for a specified quality of product estimates can be made of the broad design characteristics of a moving grate system. In practice of course it is .usual to correlate the data from this type-of :experimental 'apparatus with . existing production units upon which good operating data, in the statistical sense, are available.

Jan 1, 1963

This paper discusses how the i-kon TM Digital Energy Control System may be deployed by miners of massive underground orebodies to deliver significant advantage in terms of safety, cost and environmental compliance. Digital Energy Control offers an exciting opportunity for mine operators to review their blasting and mining practice to gain the most advantage from this new technology.

Jan 1, 2000

By D Craw

Interactions between structure and lithology in the Hyde-Macraes Shear Zone controlled the style of gold mineralisation at the Macraes mine. Large volumes of rock in some mine pits have most gold disseminated in hydrothermally altered schist, rather than in quartz veins. Mineralisation was initiated in the latter stages of metamorphism. Pods of massive schist rich in quartz and feldspar are surrounded by more fissile schist consisting of interlayered micaceous and quartzofeldspathic schist. Later shears have been partly controlled by the micaceous schist, and anastomose around pods of more massive schist. Micaceous schist was replaced by pyrite and arsenopyrite, accompanied by recrystallisation of phengitic muscovite under lower greenschist facies conditions. Gold occurs in sulfides and with microcrystalline quartz formed during minor silicification. Massive schist is locally mineralised along sulfidic microshears which have phengitic muscovite largely illitised under sub-greenschist facies conditions. Mineralised massive and micaceous schists were overprinted by cataclastic shears, with addition of graphite and more sulfides. Mineralisation occurred during a transition from ductile to brittle deformation regimes as the schist was uplifted in the late Jurassic.

Jan 1, 2004

This paper will discuss the challenges and opportunities in the years 1998 to 2002 faced by the operation and personnel at Thalanga, and its continued survival through short life projects (three feasibilities in four years). It will describe the processing of the different ores, issues faced and operating and technical innovations that occurred during that period. This will include: commissioning on very high grade Cu ores, treatment of high Sulfur feed ores (~46 per cent S) and the effects of the installation of a Detritor Mill on the process.

Jan 1, 2003

By J-H Shin, Y-S Jung, D-J Youn, G-J Bae

This research is to grope for a method to reduce high pore pressure taking place on tunnel shotcrete lining, especially in underwater tunnels, effectively by utilising a new concept of patternised pin drain. Accordingly, the patternised pin drain system is investigated numerically in order to confirm to the effect of reduction of pore pressure by the pin drain and its effective application. Installation of pin drain shows considerable reduction in the figure of pore pressure. It is found through 2D numerical modelling that the change of pore pressure, according to the shape and the location of pin drain, is sensitive by the sequences of the change of location > the change of length > the change of angle degree. In the results of investigation in 3D modelling, the pore pressure is the largest in the centre of the interval among pin drains, and it is possible to obtain an ideal degree of longitudinal angle and an interval by investigating pore pressure taking place on the lining.

Jan 1, 2008

By A J. Moore

To control the airblast from blasting to regulatory limits at environmentally sensitive sites near the Collinsville Coal Mining Operations, it has been necessary for Thiess Mining to incorporate a wavefront reinforcement analysis model in the predictive environmental airblast design. Controlling airblast from cast blasting 70 m high faces with 2000-3000 kg of explosives per hole within 700 m of houses presents a considerable challenge to the blasting personnel. This paper describes the model used and summarises the results of an investigation designed to quantify the increase in airblast indicated by wavefront reinforcement diagrams to further calibrate the model for future prediction.

Jan 1, 2004

By West RF, Pooley RH

An underground mine, a treatment plant and supporting facilities have been constructed at Lebong Tandai in Sumatra, Indonesia by PT Lusang Mining. Throughput is initially 50,000 tonnes per annum of ore with an inbuilt capability to expand to 100,000 tonnes per annum. Construction proceeded in parallel with design work on a tightly controlled critical path schedule. The very remote location of the mine, the difficult access and the fact that equipment was imported from many parts of the world presented a challenging project management problem. The transport system, which involves road, river and rail and support facilities on site had to be brought into full operation prior to the arrival of major equipment. Mine development involved the reopening of the old access drives and workings, refurbishing two shafts and the haulage system together with redevelopment of old stoping areas and the opening of new stoping areas. Ore production is now from three main areas using shrink and underhand stoping methods. Ore breaking and drive development is with conventional airleg mounted rockdrills and ANFO explosives. Exploration to locate and develop new reserves to replace ore mined is an ongoing activity.

Jan 1, 1986

This paper describes the application of the Total Productive Management (TPM) technique as a performance improvement initiative for a coal mining operation. It discusses the objectives of TPM, with the driver for improved production performance being the Overall Equipment Effectiveness (OEE) of the equipment or process, and with the development of "ownership" as the behavioral approach to equipment management and continuous improvement through cross-functional and area-based teams. It illustrates the concept of equipment management as defects management.The scope for application of TPM to the coal mining industry is immense. The harshness of the operating environment can be a major generator of equipment defects, and a current paradigm in the industry accepts these defects as an unavoidable outcome defining maintenance costs in this environment. However recent benchmarking studies have highlighted that maintenance costs per operating hour in some mining operations are more than double the vendor's estimate of "best practice". The paper refers to these studies which also compare maintenance costs of fixed and mobile plant and equipment to "best practice" outcomes in comparable process industries.

Jan 1, 1998

By Mitchell I, Gelfi P, Dunne R, Pyper R

Dump leaching at Teller in its present form began in the fourth quarter of 1988 as an adjunct to milling operations. Initial plans called for a dedicated dump leach facility capable of processing ore at an annual rate of 2.0 million tonnes. Construction of a dump leach pad, collection and process ponds, carbon adsorption system, elution plant as well as reagent addition and ancillary facilities was initiated in mid-1988. During the course of construction, additional reserves were proven. As a result, design throughput was increased to 4.0 Mtpa. Leach pad capacity and solution supply systems were upgraded to handle the larger throughput. However, the carbon adsorption/elution facilities were not upgraded due to space limitations. During 1990 it was decided to expand the dump leach operation to 6.0 Mtpa. Construction of a second leach pad was required which was initiated in early-1991. Plans were again upgraded prior to completion to a target annual throughput of 10.0 million tonnes was. A further two leach pads have been constructed. The first of these being completed during the latter part of 1992. Construction of the latest and largest pad commenced early in 1994.

Jan 1, 1994

China has abundant bauxite resources, but these resources are mostly of a diaspore, which has a feature of low Al2O3 to SiO2 mass ratio, typically ranging from four to six. Compared to other materials, this kind of raw materials consumes more alkaline and energy in the process of metallurgy, and incurred a high alumina production cost. To solve this problem, researchers in China have done a lot of work on removing of the silicon from bauxite. Under the impetus of these works, in 2003, the first flotation plant of diasporic bauxite in the world was constructed in Zhongzhou, Henan, China. Seven years of operating experience shows that this technology can signifi cantly reduce the costs of following-metallurgy processing. These efforts are an important reference for the processing of similar resource. In general, for Western scholars it is diffi cult to fully understand these works because most of them are published in Chinese. In this paper, a detail introduction for the research progress on China bauxite de-silica flotation was presented, these works involved crystal chemistry, wettability of bauxite minerals, collector and modifi er in bauxite fl otation and flotation practice, etc.

Sep 13, 2010

There are two mechanisms in the flo- tation process by which particles are transported from the pulp to the con- centrate: bubble-mineral aggregation and entrainment. It is the chemical processes which occur in the pulp which are critical to the success of flotation since they control the floatability of different min- erals and the selectivity which can be obtained. However, these chemical pro- cesses are so complex that metallurgists are still limited in their ability to predict the floatability of particles in industrial circuits by consideration of the minerals present and the chemical environment. The alternative approach to understand- ing flotation is to examine the behaviour of minerals in industrial flotation pro- cesses, to recognise similarities and differences, and to define the "laws" which appear to apply. Using this ap- proach it has been found that minerals float at a rate which is proportional to their concentration in the pulp, and that the rate of flotation of different min- erals is influenced by variables which' affect the pulp or the froth phase. The ultimate application of this approach is the use of models for circuit simulation purposes. It is this alternative approach which is the theme of this paper. One of the most important problems in understanding the technology of flotation has been in defining the characteristics of the particles being floated. Particles entering flotation vary widely in size and mineral composition, and different par- ticle types float at different rates. These rates do not change uniformly as operating variables change. It has been conventional practice to assess flotation performance in terms of the metal contents of total streams because no better method has been available, and this procedure has obscured important effects which occur in

Jan 1, 1984

By Savidis G

The characteristics of 'Z' (Back-over run) and 'R' (Reverse) ventilation systems are dis- cussed in relation to their suitability for longwall mining. Experience in European mines has been described as a basis for comparison with Australian conditions. In assessing the merits of each ventilat- ion system, such factors as longwall layout (pillar design, number of headings and gateroad stability), the need for gas drainage and bleed- er systems, as well as the influence of seam dip have been considered relevant. The R system is generally applicable for single and two heading development in seams where gas emission is a less serious problem. In contrast, the lower extraction to development ratio of the Z system (which arises from using three or more heading layouts) is considered more favourable where high gas emission occurs. The Z system provides greater flexibility with respect to the provision of refreshing air at the tailgate end, access of men and materials, installation and retrieval of gas drainage systems and the ability to interchange main- gate and tailgate roadways in cases where roof strata loads are difficult to control, or where cpam in hac an influrnra

Jan 1, 1983

By Grouhel P

Blasting performance is directly related to the characteristics and efficiency of the explosives used. The selection of the correct explosive for particular blast conditions and objectives depends on the ability to characterise the performance of individual explosive products. Techniques have been developed by the JKMRC to measure explosive performance and assess the impact of explosive performance on blast results. Studies conducted at a number of mine sites have shown that different types of explosives perform quite differently and that the performance of any particular explosive can vary significantly. The principal causes of these variations have been identified and detailed blast monitoring techniques, including the analysis of muckpile fragmentation and shape, have been used to quantify the effects of explosive performance on blast Results.

Jan 1, 1990

By M R. Davidson, M P. Schwarz

A model for column bioleaching is investigated to identify and understand aspects of bacteria in bioleaching applications, which have implications in heap bioleaching operations. The model is used to simulate scenarios that would otherwise be time consuming to perform experimentally. This study uses a model of bacterial transport and attachment/detachment to ore particles, with a bioleaching model for the depletion of a copper-sulfide, also accounting for liquid and gas flow and gas/liquid oxygen mass transfer. The model includes aspects such as oxygen and ferrous ion consumption, coupled with leaching of a copper-sulfide via the shrinking core model. The model is used to investigate how the rate of leaching is affected by the bacterial concentration in the columns, by the bacterial regeneration of the leaching oxidant ferric ions. The model is also used to assess the impact of oxygen limitation and inoculation method on the copper leaching. Some comparison of the model with experimental data will be shown.

Jan 1, 2004

By Mules GJ

Geotechnical investigations have played a key role in influencing decisions for development of the Porgera Gold Project in the highlands of Papua New Guinea. Porgera is located 130 km west-northwest of Mt. Hagen in steep mountainous terrain with high rainfall. Much of the site is underlain by weak mudstone of the Chim Formation and creeping colluvial soils. Landsliding is common on the steeper slopes and in the valley floors. Structures have had to be sited to avoid areas susceptible to these movements. Early stage feasibility investigations included studies of tailings dam and waste rock dump sites, processing plant sites and hydroelectriic schemes. Further studies, leading into the design stage included the Enga Highway upgrading, water supply and power supply schemes. As construction for the project proceeds geotechnical input remains at a high level, with emphasis now on maintaining viable stable sites and refining data on which designs were based.

Jan 1, 1990

By Streichfuss M, KeBler H-W, Burgwinkel P

This paper describes the design of an expert system used as a part of a diagnostic system for diesel hydraulic drives. A PC-based diagnostic system ruDi (KeBler and Burgwinkel, 1993) was developed to minimise the time for diagnosis and repair work of vehicles with diesel hydraulic drives used in the mining industry. One part of ruDi is an expert system that helps to locate errors in any of a vehicle's subsystems, and supports technicians in removing the cause of a malfunction. Apart from the standard knowledge of diesel engines and hydraulic transmissions, the expert system supports the interpretation of the data obtained during sophisticated engine analysis tests such as high-resolution speed analysis or high-pressure analysis of the diesel injection system. The expert system is designed to diagnose various vehicles of the same type. Data for each vehicle is stored separately allowing checks to be carried out individually for each machine. An additional feature of this system is a database interface to a Maintenance Planning and Control System (MPCS) that allows an automatic generation of work orders for the defects found during the expert system sessions.

Jan 1, 1995

Sampling criteria and practical implementation of these criteria are discussed with a view of achieving and maintaining a high level of quality for minerals at their various stages of production through to their utilisation. From this it will be shown the advantages that can be gained by producers who undertake stringent quality control programmes for their ores, thus ensuring they have a competitive edge over other producers.

Jan 1, 1985

By Shonhardt JA, Bagster DF

This paper firstly examines the pollu- tion potential of burning colliery wastes. A comparison of two means of estimating the pro- pensity for coal to combust spontaneously is next presented. The use of microwaves, as a new procedure, is discussed in detail, while a comparison of the results is made with a modi- fied adiabatic technique. A number of coals that are known to combust spontaneously was tested, as were some coals that are not consi- dered to have self heating potential.

Jan 1, 1987

By Tsuchiya N, Takada Y, Okabe K

Alkalis in the blast furnace are removed mainly by the slag, Alkali removal by the slag was studied as a rate process of alkali vapor- ization from the slag flowing through the dropping zone in the blast furnace. The vapor-, ization rate of I:20 from CaO-Si02-A1203 IZ20 slag was- measured under various experimental conditions. An empirical formula for the vaporization rate was obtained as a function of slag basicity, temperature and surface area per unit mass of slag. A simulation model of IC20 vaporization in the dropping zone was evaluated using the rate equation when the true velocity and surface area of the slag was de- termined from a flow dynamic model of counter- current gas-liquid flow through packed beds. The influence of the dynamic conditions of flow, as well as the slag basicity and temperature, on alkali removal by the slag was estimated.

Jan 1, 1980

By Lauricella P. F, Hendri D

In the Mesel sediment-hosted disseminated gold deposit, the spatial distribution of hydrothermal alteration is controlled by steeply dipping faults and shallowly dipping lithologies. Hydrothermal alteration of carbonate rock is characterised by decalcification, dolomitisation and silicification. Intense argillic alteration occurs in a laccolithic andesite intrusion adjacent to decalcified and silicified carbonate units. Sulphide minerals (pyrite, realgar, orpiment, stibnite and cinnabar) accompany hydrothermal alteration and precious metal mineralisation. The trace elements Ag, As, Sb and Hg are zoned spatially throughout the deposit. Mesel contains a mineable gold reserve of 7.8 million tonnes at 7.3 g/t Au. Gold mineralisation is preferentially localised in carbonate rocks adjacent to and beneath the andesite intrusion. The ore body consists of a central, near-vertical, high grade "feeder" system flanked by tabular, inward dipping, moderate grade "ouflow" zones. Mineralisation is controlled predominantly by two steeply dipping faults with high grade (>10 g/t) gold zones centred about structural intersections and fault splays. Gold is submicron size and locked in very fine grained (

Jan 1, 1995