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By N Ozawa, R Kaneko, M Arimit

The Mitsubishi Higashitani limestone mine is a ten million tonne per annum operation located near the city of Kitakyushu on JapanÆs western island of Kyushu. Higashitani is one of the largest limestone mines in Japan and accounts for about five per cent of national production. Blasting practices at the Higashitani mine involve the use of bagged ANFO, dynamite primers and non-electric detonators. Regulations in Japan prohibit the use of site mixed bulk explosives. Blast size is usually around 17 000 tonnes with 20 holes in a single row, two or three blasts are fired per day at a powder factor of between 0.25 and 0.32 kg/m3. As part of a program looking at oversize reduction Mitsubishi, Asahi and Orica agreed to conduct a joint project at the Higashitani mine to investigate the relationship between the powder factor and fragmentation. The first stage of the project was to benchmark the current blasting performance. Five blasts were monitored in each of the 210 (hard rock) and 220 (soft rock) areas of the mine. OricaÆs Powersieve« software was used to measure fragmentation and total rock breaker hours were also recorded for each blast. OricaÆs computer blasting simulation model Sabrex« was used to prepare revised blast designs with a higher powder factor and predict their performance. The performance of these blasts was monitored using the same methods.

Jan 1, 2004

By Perring CS, Barnes SJ

The nickel exploration boom of the late-1960s and early-1970s led to the discovery of numerous komatiite-hosted nickel sulphide deposits, associated with variably serpentinised bodies of olivine-rich cumulates. Subsequent research has shown the importance of volcanological processes to understanding the genesis of these deposits. Crucial developments have come through consideration of the fluid dynamics of magmas and magma-crystal mixtures, through observation of the dynamics and geometry of modern day basaltic lava flows, through application of theory and experimentation on the kinetics of crystal growth from magmas, and most importantly from extensive detailed field mapping of komatiitic sequences in the Yilgarn Block and elsewhere. From these studies has emerged a new integrated view of the volcanological setting of komatiite-hosted deposits, and a recognition that a complete continuum of deposit types exists. Nevertheless, komatiite associated magmatic nickel deposits generally fall into two overall types based on the nature of the sulphide ore. In the first type the bulk of the ore is either massive Fe-Ni-Cu sulphide or a variable mixture of massive sulphide and an ore characterised by olivine crystals in a continuous matrix of sulphide occupying between 30 and 75 per cent by volume of the rock (called Matrix Ore). Nickel grades of massive sulphide ore range from 2 - 20 wt% and those of the matrix ore generally fall in the range 1 - 5 wt% (average 2.5 wt%) Ni/Cu ratios of the sulphide fraction are generally >10.

Jan 1, 1996

A simulation program has been developed tc predict the airflow distribution and thermal environment in multi-level narrow lode Cornish =n mines. Because of the approximate equality between fan power and natural ventilation _rergy a true thermodynamic mesh balance using mass flow rather than volume flow rate was required. Compressibility is allowed for by calculating mesh corrections on a mass flow of dry air basis. In this context, and within the confines of any steady state model, both the steady flow energy and pressure equations are satisfied with equal validity. The mesh balance includes natural ventilation energy, frictional losses, moisture lift work, water droplet energy and fan energy.

Jan 1, 1988

By Fink ST

Management requires up-to-date information on the activities of an enterprise in order to maintain control and to assist in decision-making and planning. In today's environment it is essential that this information is immediately available and in an easily assimilated format. If this is not the case, management is forced to make decisions based on intuition and past experience. At Mt Newman Mining Co, a computer application has been developed and implemented with the objective of providing this type of information to management. The Key Parameter Reporting System (as the application is known) allows for daily (constant) on-line capture of selected production statistics, safety statistics and free format textual comments relating to topics such as industrial relations, major maintenance and other pertinent news. Information can be retrieved,'and displayed or printed in either a tabular or graphical format. All senior managers have colour visual display units in their offices for immediate access to the system. Access to selected sensitive information is controlled. All company staff are able to retrieve unsecured information from the system via visual display units installed in all company Locations.

Jan 1, 1983

By Propster M, Choudhry M

THIS note gives comments on the paper by Kitaev et al on p. 68 of this book and compares results with those obtained by ourselves. We wish to say that the authors are to be congratulated on their sophisticated approach to an important problem and that it complements our efforts on flow maldistribution.1-5 It is our view that Eqs. (1)-(5) on p. 69 are impressive, but unfortunately with present day computers and computational facilities, it would be quite impractical to contemplate the numerical solution of these. Eq. (8) in the authors' paper, on p. 70, does provide the logical starting point for tackling flow maldistribution problems and strictly speaking this equation is more accurate than Eq. (1) in our paper in this book. We note in passing that there is direct experimental evidence to support the contention that our Eq. (1) is at least a reasonable approximation and one may question in a practical sense whether the refinement afforded by Eq. (8) in the paper by Kitaev et a/ is justified. While one must readily accept the appropriateness of Eq. (8) of Kitaev et al as a starting point, the subsequent mathematical manipulation by the authors is open to serious criticism. In order to solve this complex, non-linear equation Kitaev et al postulated irrotational flow, which afforded considerable simplification. One can argue simply on physical grounds that the assumption of irrotational flow is inappropriate, a fact which should be readily apparent on inspection of the flow fields shown in Figs. 2 and 3 of Kitaev's paper. It follows that while the starting point through the use of Eq. (8) is correct the results derived from this starting point may be suspect because of the erroneous nature of the irrotational flow assumption.

Jan 1, 1975

A simple method of designing effective fill drainage systems for slurry backfill is presented. By using the proposed method, it is easy to calculate and predict the expected fill drainage rates or to provide additional drainage systems to accelerate the fill drainage. The fundamentals of hydraulic fill and an efficient method to determine its permeability is also explained. The safety in hydraulic filling and bulkhead stability depends totally on achieving effective drainage regime for the fill. This paper provides the basis for creating such efficient drainage regimes. The recent fatal fill bulkhead failures in Australia were the result of poor drainage from the respective fill masses, and therefore it is more important to provide suitable drainage arrangements to continue using hydraulic fill to the benefit of the mining industry. At present there is no procedure available to mine operators to estimate the expected bulkhead pressures to design a satisfactory bulkhead. Some mines are constructing bulkheads after their initial investigations carried out years ago. Other mines have simply borrowed the ideas from the pioneer mines and using in their areas. It is high time that we develop a rational approach to estimate the expected bulkhead pressures for the design of bulkheads. We need a simple model that could be understood and used by the mine operators on a day-to-day basis. This paper also presents a model to predict the bulkhead pressures for designing safe bulkheads.

Jan 1, 2002

By M Scoble, W S. Dunbar

This paper reviews methods for grade estimation in short-term mine planning for block caving. Two particular tools are used: Ordinary Kriging and Simple Kriging with moving averages. It is also considered the influence of draw characteristics on the grade estimation process. Reference is made to mine case study data and analysis. These demonstrate that operational grade estimation is not a trivial process. It must take into consideration: the grade variability (in terms of ore and dilution), sampling interval, geological and geotechnical characteristics, geometrical layout and draw characteristics. Significant improvements appear possible in short-term planning if variogram analysis, as well as kriging methodologies, are introduced into the operational grade estimation process.

Jan 1, 2000

By Hart A. T, Lanigan P. G

BHP is currently undertaking research into plasma are metallurgical processing at the Central Research Laboratories (CRL), Shortland. The use of high intensity plasma arcs for melting and smelting has a number of advantages, including; the ability to control atmosphere and furnace operating conditions, total enclosure, high temperatures, versatility, and low in-process inventory in a compact system. The intensive conditions, achievable in a plasma furnace system, make it particularly useful for the smelting and melting of difficult-to-treat materials, such as ore and metallic fines and refractory ores. Two transferred arc plasma smelting furnaces have been set up at CRL; a 100kg furnace is used for small scale melting and smelting studies and a 1 tonne furnace for pilot scale plasma processing studies and equipment development. Power is supplied by a 1MW GEC thyristor DC power supply. A 220kW DC power supply is available for "off site" pilot process trials and demonstrations, and a 150kW non-transfered are plasma torch is also available for other studies. The facility has been designed to allow maximum flexibility in researching and developing applications in metallurgical processing and transferring developed technology to company operations. The objectives behind the development of the facility, details of the facility and an outline of current research areas will be Discussed.

Jan 1, 1987

Alternatively are they a necessary evil'? Exploration geologists are a much higher profile group but then again the higher they are the bigger they Bill. At a mine site they are reluctantly being accepted as equals by mining engineers given the requirements of the `Code' in the reporting of Ore Reserves. How best can mining geologists service their customers? Are more revealing questions to be answered in who are their customers? In the past mining geologists lived isolated existences pouring over plans and sections, now with user-friendly software packages available and the use of LAN, mining geologists and mining engineers talk electronically - God forhid what the future might hying - they might even talk to accountants and metallurgists!

Jan 1, 1997

It should be noted that with the passage of time all aspects of the mineral extraction process are becoming more sophisticated and complex. In order to deal with this, the education system should be geared to this continual technological advance.A new scheme is designed to attract high quality school leaven to take up courses serving the mineral industry. After graduation these students will play an important role in the areas of research and development which is essential for the growth of the Australian mining industry.

Jan 1, 1991

By Howlett P. F, Courtley S

A problem with secondary breaking at one of the mines of Pasminco Mining led to a study of new rock breaking technologies. Many of the techniques being developed had emerged from the thrust in the USA for continuous drill=break excavation. Such approaches to rock breaking highlighted the applicability of what would normally be classified as tunnelling techniques, to the secondary breaking sector - and possibly the reverse. As a direct result of the investigations for suitable technologies, Pasminco Mining supported the development of two improved rock breaking methods specifically targeting secondary breaking, one of which could be applied to continuous excavation.

Jan 1, 1993

By I H. Jung, W O. Choe

Gallium (Ga)-containing compounds such as Gallium Arsenide (GaAs) and Gallium Nitride (GaN) are widely used in electronic devices due to their superior electro-optical properties and their usages increase rapidly. For the sustainable supply of Ga to electronic industry, therefore, the recycling of Gallium becomes essential. Pyrometallurgical Ga recycling process involves the complex chemical reactions between slag, matte, liquid metal, gas, refractories, etc. Therefore, the accurate thermodynamic information and phase diagram data for the oxide system containing Ga2O3 is important. In the present study, new phase diagram experiments for binary SiO2-Ga2O3 and ternary CaO-SiO2-Ga2O3 system are carried out using Differential Thermal Analysis (DTA) and quenching experiments followed by Electron Probe Micro-Analyser (EPMA) and X-Ray Diffraction (XRD) phase analysis. Based on new phase diagram data and available literature data, the thermodynamic modelling of the entire CaO-SiO2-Ga2O3 system is performed for the first time.

Jun 19, 2024

Design of underground extraction layouts to protect surface improvements is an important area of subsidence research in the Coal Mining Engineering Branch of the Department of Mineral Resources, New South Wales, Australia. Some conventional partial extraction layout are important with reference to coal recovery and surface subsidence. The analysis ofsubsidence data collected from field surveys over longwall panels in the Southern Coalfield of New South Wales allows assessment of the effect of pillars left unmined between the longwall panels in reducing surface subsidence. The availability ofa wide variety of layouts with ranging degrees of surface movements affords considerable flexibility in designing layouts to suit a particular situation.Total extraction of coal should be the aim as far as possible. Partial extraction layouts should only be considered when surface subsidence movements caused by total extraction are not acceptable to the surface improvements.

Jan 1, 1985

By B McFadyen, Y Potvin, K Woodward

The Australian Centre for Geomechanics (ACG) held two workshops in 2019—one in Australia and one in Canada—to discuss processes and methods currently used in the mining industry for stope design and reconciliation. In practice, this work strives to optimise stope performance and aims to maximise ore recovery (minimise underbreak), while minimising dilution (overbreak). One of the key findings from the workshops was that current stope design practices, almost exclusively, rely on some versions of the empirical Stability Graph methods developed in 1980s. Although robust and useful at the feasibility study stage, there are a number of inherent shortcomings with this approach. The Stability Graph’s limitations first lie in that it cannot assess underbreak, which is a very important measure of performance. Furthermore, the method doesn’t consider a number of factors which often have a critical influence on stope stability, for example, drilling and blasting or the presence of faults. Given the current industry standard practice, there is a great opportunity to reinvent the stope design process to optimise performance. A finding of the workshops was that every mine quantifies stope performance in terms of volume reconciliation with a focus on dilution and ore losses, and reconciling metal tonnes recovered from the mill. Many mines further investigate stope performance by looking at individual stope faces and the causes for the deviations between the planned stope shape and the measured cavity. Recent research at the ACG has shown that investigating overbreak and underbreak at a higher resolution is a powerful way to identify the root causes of overbreak and underbreak. Finer scale assessment is achieved using an octree analyses, which effectively divides the relevant stope volume into cubes on the scale of a metre and produces many tens of thousands of data points. The octree data structure and subsequent analysis underpins a data-driven stope design methodology. The ACG is currently developing a design approach based on multivariate modelling methods that can account for the many variables that influence stope performance and forecast stope overbreak and underbreak results. Back-analysing stopes based on octree reconciliation results provides a rich database for training the model. Once the model can achieve reliable forecasting of overbreak and underbreak, an interactive drill-and-blast design will allow for the assessment of different firing strategies to optimise stope performance.

Mar 15, 2021

By Moyes A. J

The Intec Copper Process uses a strong chloride electrolyte at atmospheric pressure and 80 - 85¦C to produce high purity, 99.99 per cent copper granules and elemental sulphur. A recent, exhaustive study by an independent, major Australian corporation has shown the capital cost of an Inter plant to be approximately half that of a copper smelter at the 200 000 tpa capacity level and approximately half the operating and capital cost at the 50 000 tpa level. The Inter process costs were also shown to be greatly superior to the best available leach/SX/electrowin technology. The process utilises a multi-stage counter current leach at 80 - 85¦C with the addition of air at atmospheric pressure to precipitate iron as a goethite type compound, followed by a two-stage purification process separating impurities in metallic- and other forms. Purified cuprous chloride/sodium chloride solution is fed to an electrolytic diaphragm cell where high purity copper granules are produced at current densities of 1000 - 1500 A/m2 withoutthe need for conventional electrode stripping. Power consumption is approximately half that of the cupric route. The product is suitable for the direct powder metallurgical conversion of the granules to products such as wire or strip. All the steps in the 'furnace free' conversion of copper mineral to product have been demonstrated The process can treat low grade and contaminated concentrates without penalty, thereby offering greater returns to the miner. Lead, zinc and silver may be recovered as metals, with the high oxidation potential of the electrolyte allowing extraction of gold at high efficiency. The gold is selectively precipitated on activated carbon with negligible copper and silver contamination.

Jan 1, 1992

By Y L. Ma, Y Yang, M Chen, W Bruckard

To improve the understanding of the reactions and mechanisms occurring during the leaching of sulfide ores at high temperatures a range of advanced characterisation and sensing tools have been combined to provide a sophisticated and powerful methodology to examine sulfide leaching systems. These include advanced electrochemical methods, surface chemistry and materials characterisation techniques such as synchrotron X-Ray Absorption Spectroscopy (XAS), X-Ray Photoelectron Spectroscopy (XPS), Scanning Electrochemical Microscopy (SECM), and in situ X-ray diffraction (XRD), together with new robust solid state chemical sensors for in situ real time monitoring of key aqueous chemical parameters. The methodology was employed to investigate various sulfide mineral leaching processes. For example, oxidation of arsenopyrite at elevated temperature involves complicated multiple reactions and the process is strongly influenced by the solution conditions, component speciation and mineralogy. The methodology was used to study this system both ex situ and in situ to gain a detailed understanding of the complex chemical reaction mechanisms operating. These mechanisms are discussed in terms of the observed leaching efficiency. The application of this methodology enables complex sulfide leaching systems to be understood more fully such that process efficiency can be improved.

Aug 24, 2022

Robe River Mining manages a large open pit iron ore mine in the Pilbara region of the North-West of Australia. The mine is managed for various joint venture participants.In July 1986, Robe River Mining made various changes to its management philosophy, which were heavily publicised in the media at the time.As a result of those changes to its management philosophy, Robe River Mining has been able to dramatically increase its production output, productivity, and safety performance without having to resort to major capital outlays and without the benefit of restructuring of applicable industrial awards.

Jan 1, 1992

With some notable exceptions, marine placers located just below, or just above, present sea level, are responsible for much of today's production of detrital ilmenite, rutile, zircon, and other minerals of value. The purpose of this paper is to discuss the paleogeographic and paleo-oceanographic factors which may have determined the location of presently submerged marine placers. These factors-include changes in sea level, burial by recent marine sediments, stream capture and other i changes in drainage patterns, and recent changes in climate. Selected geologic situations in the Yellow Sea off the coast of Korea, in the Atlantic Ocean off the coast of Portugal, in the Bering Sea off the coast of Alaska, and in the Arabian Sea off the coast of India, will be used to illustrate the author's point of view.

Jan 1, 1980

Reverse circulation (R.C.) drilling or the dual tube method as it is quite commonly known, has a unique place in conventional mineral drilling. It can be classified half-way between open hole drilling at the lower end of the scale and diamond drilling at the upper end. The system basically consists of two tubes, one inside the other, with compressed air flowing between the inner and outer tubes. Sample cuttings return up the inner tube through the head of the rig and via a hose to a cyclone where the sample is collected. This system means that the cuttings are free of contamination as they are at no time in contact with the outside formation of the hole.Reverse circulation drilling is divided into two areas: R.C. Roller and Blade for softer formations; and R.C. Percussion for harder formations.

Jan 1, 1986

Draglines have been a significant part of world open cut mining since the early part of the 20th century particularly for the removal of overburden in the strip mining of coal. Since the mid-1960s draglines have played a major part in the large strip mining coal developments of Queensland and New South Wales.There are now over 60 large draglines operating in Australia ranging in size from 23 to 103 cubic metres bucket capacity, with digging depths to 60 metres, dumping heights to 50 metres and dumping radii to 100 metres. The application of these draglines has progressed through the uncovering of coal in shallow, single seam operations to deep multi-seam operations requiring a greater dependence on pre-stripping activities ahead of the dragline to remove overburden not able to be efficiently handled by the dragline.

Jan 1, 1992