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Three separate and unconfined aquifers occur in the Hilton area, named relative to position in relation to ore horizons: Footwall Aquifer in the east; Ore-Zone Aquifer within the ore-bearing Urquhart Shales; and the Hangingwall Aquifer in the west.It is the on-going strategy it Hilton to drain the Ore-Zone Aquifer which occupies structurally- and sulphide-controlled leached zones in the steeply west dipping strata. The aquifer affects considerable ore reserves to 480 m below the surface. Dewatering began in 1976, and is essentially completed to 4 level (240 m below surface). Dewatering efforts are now based on 8 level (480 m below surface).

Jan 1, 1993

By Bartosiewicz H

A method for the determination of the gas content of coal seams is presented which improves upon existing methods. The method makes use of a gravitational technique for measurement of the gas desorbed. The amount of lost gas is estimated by determining an empirical relationship relating the desorption of gas with time for each sample separately. This is to replace the assumption that desorp- tion follows a square root law with time. Laboratory investigations have been conducted which indicate that the square root desorption law does not hold good for carbon dioxide. Results of investigations on various factors influencing the technique are presented. It is shown that co-efficients of the empirical equation are dependent upon the elapsed time and the period of observation. Data about gas pressure measurements is presented and it is concluded that gas pressure can be approxi- mated to 0.6 times the pressure below a column of water equal to the depth of cover. This estimate is good enough for adsorption tests to evaluate desorption co-efficients. The technique for repressurisation of the sample,

Jan 1, 1982

By Todd S, Lam K, Hewitt A

A series of field experiments investigated the perfonnance of fine mesh curtain screens which were used to suppress coal dust in a transport roadway of a New South Wales colliery. Four types of screens were tested under dry and wet conditions. The screen materials consisted of flyscreen and garden "shadecloth" with single and double membranes of both materials. Personal dust samplers coupled to dust cyclones and filtration cassettes were used to collect the respirable and total components of dusts respectively. The procedure used for locating the samplers upstream and downstream of the screen was based on the roadway air velocity profiles. The number and configuration of the water sprays impinging onto these screens had significant influence on the results. The study showed that wet double layered flyscreen is the most effective of the four configurations tested.

Jan 1, 1991

By Esaki M, Nishimura K

This paper describes the results of the field application tests at Miike Colliery on the integrated automatization of the longwall mining system for medium thick coal seam. The purpose of the research is to develop an automatic longwall mining system which can be controlled accurately from outside of the face, and the ultimate goal is an eliminate of men from the face. Presently, the field test is being conducted in Yotsuyama mine following to a success in the performance test on surface. Remote Batch Control System for shield supports has been adapted to operate all supports from the control panel located at the entrance of the face. Remote monitoring and control system of the drum shearer has also been tested. The system makes it possible to operate the shearer either at the main gate or full automatic. Productivity and safety will be substantially improved as those systems enable to eliminate all workers from the face under the severe working conditions with high ground pressure and hot and humid atmosphere due to increasing mining depth. So far, we have been satisfied with the results of the field test and those system will be an effective countermeasure to operate the face with a high risk of rock-burst.

Jan 1, 1987

By R Salmimies

Choosing a ceramic capillary action filter is often favoured in processes where low energy consumption is important, such as the dewatering of iron ore. In addition, the performance of the filter medium is essential, and the possibility to regenerate the medium is an advantage compared to other types of filter media. Although low, roughly 8 - 9 w-per cent for iron ore concentrate, and even cake moisture is the primary goal of dewatering, the introduction of better filtration processes can result in significant improvements of water economy and material efficiency.As industrial beneficiation processes are often complicated in their chemistry due to impurities originating from the ore itself, from the up-stream processing equipment and from the process water used, the characterisation of the filter media after usage might provide relevant information on what actually takes place during long operating periods. The aim of this study was to obtain new information on the fouling of fi lter media in an iron ore process to enhance and develop the regeneration process of the media in the future.X-ray diffraction and scanning electron microscopy were used to characterise ceramic filter media used in the dewatering of magnetite. Principal component analysis and discriminant analysis were introduced to identify trends in the data. Two types of media blockages were found to play an important role in an acidic iron ore dewatering process: fouling by slurry particles and by in situ crystallisation of a calcium compound, of which the latter originated from the combination of process water and process chemistry.

Jul 11, 2011

Autogenous and Semi-Autogenous grinding has become an accepted method of reducing primary crusher product to micron sizes in a single or a two-stage grinding circuit. The elimination of secondary and tertiary crusher circuits and sometimes rod mills helps to lower overall operating costs and, in many instances, can make uneconomical projects viable. Selecting AG/SAG Mills have been rather a "hit and miss" affair over the years, but now with the many different types of tests available, accurate mill size predictions can be made, provided the test data is evaluated correctly. This paper endeavours to simplify the process of evaluating test data and sets down some guidelines for designers to follow when selecting AG/SAG Mills.

Jan 1, 1991

By Guo-Zheng J

This paper describes the risk management strategies adopted to control unstable slopes in the east open pit of the Daye iron ore mine. Extensive experience has been developed over the last 35 years in the management of pit wall instability resulting in the successful excavation and reinforcement of pit slopes over 350 m in height.

Jan 1, 1994

The statistical nature of the variability in detonation times of pyrotechnic delays is discussed, and how to evaluate the probability of required detonation intervals is shown. Some methods (analytical and stochastic) are given for designing blasts to ensure that any adverse effects on the variability in the delays is taken into account and minimised. Using computer models of blasts, detonation simulations can be used to check the initiation sequence for the probability of sequence reversals, indicating areas of high blast damage potential. Charge consumption rates, which relate directly to the resulting vibration levels, can be examined for their susceptibility to variation from delay variability. Models that synthesize vibration waveforms for production blasts, when taking delay variability into account, indicate the difficulty in vibration level prediction.

Jan 1, 1992

By Christie GB, Mainwaring DE, Leong YK

High solids brown coal slurries have been prepared with concentrations approaching those achieved with bituminous black coals. The high inherent water content and macroporosity of Victorian brown coals have been reduced in a controlled manner by chemical and mechanical means. The hydrophobicity of the coal surface has been increased sufficiently to reduce the tendency for swelling and water uptake. This together with densification has allowed the solids content to be progressively improved from 25% solids with raw coal to 65% solids with modified coals. Both raw brown coal and modified brown coal suspensions show shear thinning behaviour resulting in lower viscosities at higher flow rates. All coal suspensions displayed a yield stress once sufficient solids concentration was achieved. This yield stress can be used in the prevention of solids settling. Under simple shear mixing the network structure that provides the yield stress quickly breaks down to a low viscosity fluid with reduced yield stress and a pumpable consistency. The time necessary for structural recovery is in the order of days permitting shut-down and start-up of fuel delivery systems.

Jan 1, 1987

Thermo Fisher Scientific is the worldÆs leading supplier of analysers for laboratories and process industries. The companyÆs X-ray fluorescence (XRF)-based slurry immersion probes were originally developed by the acquired Amdel Instrumentation. These analysers have found limited application within wet beneficiation plants for measurement of iron. The recent trend of renewed efforts to maximise recovery from existing resources and lower costs has increased industry interest in online analysis. In the mid-1990s the company developed online analysers (the light element slurry analyser û LESA) for slurry applications using the prompt gamma neutron activation analysis (PGNAA) method. The company has successfully installed LESA for the direct measurement of lighter impurity elements in Brazilian plants using flotation for rejection of silica. A case study is presented. The PGNAA technique has the unique ability to provide elemental analysis of bulk materials on a conveyor belt. The company released its eighth generation cross belt Omni analyser using PGNAA in 2007. Results from a recent project with sinter are presented. The Niton range of hand-held XRF analysers is also supplied by Thermo Fisher Scientific. These handy devices are finding widespread use in the mining industry to provide quick and easy analyses in exploration settings. In contrast to PGNAA this is a surface technique. A prototype for light element analysis is being tested for iron ore.

Jan 1, 2007

Polish coal mines are well equipped with methane monitoring systems,nevertheless the worsening conditions force a continuous impro- vement in the field of environmental monitoring. Application of modern electronic components make it possible to design the new modular telemonitoring system incorporating the best features of the older systems,widely employed in Polish collieries, eliminating their weak points. Several new sensors and portable instru- ments for methane monitoring and early fire detection have been developed and tested in mining conditions.

Jan 1, 1988

In seeking to improve the economic performance of mines, the management or human aspects are usually seen to be quite seperate from, and more significant than, the technical aspects. There are obvious aspects of industrial relations, man-management, skills training and supervision that are currently the focus of efforts to improve the productivity and quality of the mining process. However technology also has a lot to offer. Analysis of the costs involved suggests that innovations leading to improvement in the productivity of the excavation and transport of overburden and the recovery of coal (both in the mine and preperation plant) can lead to improvements in the economic performance of a mine that may outstrip the obvious non-technical or management opportunities for improvement. While there are some innovations currently being investigated within the industry that relate to the design of mining equipment, the type of machinery being used in open cut mines has not changed dramatically over the last twenty five years. It is also likely that mining equipment will remain essentially of the same form in the forseeable future. If significant improvements to mining performance are to be achieved other than by futher increases in the scale of machinery, then we need to seek ways to operate these same types of machines in a more productive and controlled manner. This paper discusses the identification of mining processes the improvement of which is likely to have a significant effect on mining costs and performance. Some areas of current research are discussed and potentially fruitful areas for future development are identified.

Jan 1, 1991

By Lawless JV

Recent exploration for gold on the Pacific Rim has utilised similarities between active hydrothermal systems and epithermal gold deposits. The major control over formation of such deposits is the hydrology of the ore-depositing hydrothermal system, which varies depending upon its geologic setting.

Jan 1, 1987

By M Badawi, Y Foucaud, C Veloso, J Laine, A C. Araujo

Iron is one of the most exchanged commodities worldwide. Its use for steelmaking explains the growing demand in the metal which remains mainly produced by the mining and the beneficiation of iron ores. Flotation is the most used mineral separation technique worldwide, processing several billion tonnes (Bt) of ore annually, including, in some cases, hematite and magnetite ores. Based on the physicalchemical properties of mineral surfaces, flotation aims to selectively adsorb molecules that render mineral surfaces either hydrophobic or hydrophilic, known as collectors and depressants, respectively. Hydrophobic particles are then recovered in the froth by the injection of gas bubbles travelling up in the cell and attaching the hydrophobic particles. However, despite the popularity and the good performances of flotation, mining industry faces new challenges of decreasing grades and increased mineralogical complexness in ores. Many flotation variables, especially when related to reagent adsorption, remain poorly understood and it becomes necessary to gain knowledge to enhance the existing processes. Molecular modelling techniques like the density functional theory or molecular dynamics simulations (ie Classical molecular dynamics or Ab initio Molecular Dynamics) currently represent powerful tools for different applications in material sciences, like catalysis or depollution purposes. They have recently been successfully applied in the flotation area, with an increasing number of publications dealing with this topic every year. These tools provide crucial information on bulk and surface properties as well as on the adsorption mechanisms of reagents on mineral surfaces, key step in the flotation process, and synergetic effect of collector mixtures. A better understanding of the adsorption mechanisms of flotation reagents, provided by molecular simulations, will help to finely choose flotation reagents, and even lead to the development of new reagents formulations. Overall, these tools enable the discovery of practical and industrial solutions to improve the flotation process, which will undoubtedly help the mining industry to face its future challenges.

Nov 8, 2021

In this paper is given a description of the flotation plant recently erected by Broken Hill South Limited at the South Mine, Broken Hill, N.S.W. It has been built on the site of the old flotation plant, which was described in a previous paper published by the author. The present paper is supplementary to the former paper in that it replaced the following sections thereof, namely, those from end of the second paragraph, page 269, to the end of the first paragraph page 282, and from the end of the second paragraph, page 284, to the end of the third paragraph, page 302.The roll crushing, fine grinding, gravity concentration, filtration, disposal of products and sampling in the new plant are the same as described in the above mentioned paper.The reconstruction of the flotation section, described herein, completes the reconstruction and modernisation of the treatment plant which was begun in 1928. A description of these earlier alterations has already been published in the Proceedings of this Institute.

Jan 1, 1935

The article, as written, represents a short account of the treatment of the base bullion from the Broken Hill ores, as carried on at Port Pirie, for the recovery of lead, silver, and gold, and for the treatment of by-products. Appended is a short description of the chief facilities of plant which have been adopted to overcome the main difficulties in the refining of lead the Howard press and stirrer. The article is within the limit prescribed by the regulation for the prize offered by the Australasian Institute of Mining Engineers, comprising 30 pages, containing an average of about 200 words per page, exclusive of analyses, photographs, and sketches.The writer desires to thank those to whom he is indebted for their- kindness in affording him every facility possible to obtain the information which he required for the success of such a paper-viz., Messrs. Robertson, Leavens, and Gronow, of the Broken Hill Propritary Co. Limited, at Port Pirie, and Mr. Crowther, of the Adelaide School of Mines, to whom he is indebted for photographs. The difficulty of obtaining fair samples of gold drosses, and the inability to obtain particulars of fuel consumptions, prevents the paper from being as complete as one would wish. The limited length precludes detail, except in more important parts.

Jan 1, 1907

By Jarvensivu M, Ylinen R, Jamsa-Jounela S-L

The paper presents a new integrated system for control of concentration processes. The system is based on cluster-based modelling taking the ore quality into account and a new on-line particle size analyser capable also for reliable measuring of particle size distribution of concentrate. A metallurgical precontrol audit was performed at the Hitura concentrator in order to design the control strategy of the integrated grinding and flotation control. A new analyser PSI-200, was used to the measurement and control of the distribution of nickel in the total particle size range. An expert control system using the cluster model together with a new control strategy for decision of necessary control actions is outlined. The method has been tested to real data from mineral processes. The results are in good correspondence with empirical process knowledge. KEYWORDS: Cluster analysis, expert control, flotation control, mineral processes, modelling, particle size.

Jan 1, 1993

By Hinde J. S

The Fitzpatrick Orebody is a three and a half million tonne fault bounded portion of the early-middle Proterozoic Broken Hill Orebody.The Fitzpatrick Orebody was discovered in 1975 by diamond drilling from the 36 Level Exploratory Drive. This followed persistent geologically oriented exploration and a courageous decision by mine management to deepen No. 3 Shaft to provide exploratory development across the Globe Vauxhall Shear and allow effective drilling of the target area.The stratiforrn oebody consists of three lenses, the lead rich No. 2 and 3 Lenses and smaller zinc lode. They represent a down plunge extension and boudinaged, fault-bounded portion of the main Broken Hill ore lenses. The surrounding host rocks are extensively faulted and jointed due to complex history of movement on the bounding shears. This results in extremely poor ground conditions during mining. The ore was delineated for mining development using three dimensional fan drilling from exploratory and hanging wall drive drill sites.

Jan 1, 1990

The title of this paper suggests rather a comprehensive survey of the industry, but since it is not possible to do justice to this in a short paper, and, as the bulk of the Australian trade consists of buttwelded tube, the author proposes to deal only with this type.The buttweld process has been praetised for many years and, as the methods of manufacture are not widely known, a brief history of its development may be of interest. Few good reference books in the English language are available, and this reticence may possibly have retarded advancement in manufacture.The earliest method of making ferrous tubes consisted of bending a thin plate or strip to form a "skelp." The "skelp" was then raised to a welding heat and hammerwelded on an internal mandrel on a smith's anvil. Necessity, however, soon produced mechanical methods of making tubes, and, in 1812, an Englishman named Osborn patented machinery for "welding and making barrels of fire-arms and other cylindrical articles." The apparatus was arranged as shown in Fig. 1.The skelp was raised to a welding heat and placed in the swage block "A." A mandrel was then inserted and the tube lapwelded by the action of the tilt hammer.Various modifications of this apparatus quickly followed, to keep pace with the rapidly growing demand and the exigencies of war. These tubes were essentially of short length and mainly used for gun barrels. The advent of coal gas for lighting (patented by Murdoch) created a demand for small tubes of longer length, and necessity, as usual, produced a solution. In 1824 Jas. Russell, from *Works Manager, Stewarts & Lloyds (Australia) Pty. Ltd.

Jan 1, 1935

By Sans H

The geostatistical Discrete Gaussian (DG) model is demonstrated to be capable of providing an effective means of implementing change of support for Enterprise-style mineralisation and thus providing reliable global recoverable resource estimates. At Enterprise, sample grade distribution proves to be highly positively skewed, therefore significant deskewing of the histogram and reduction of variance occurs when going from sample to block support. The DG model was experimentally tested in'the Southern Primary Zone (SPZ) at Enterprise, where high anisotropy ratios and pronounced short range structures are observed in variograms. The experimental test was run for a change of support for which the variance reduction was. approximately 60 per cent. This reduction is similar to that predicted by Krige's Relationship ('the volume-variance relationship') for the practical situation of a change of support from 5 m vertical blasthole samples to 3 m x 8 m x 5 m selective mining unit (SMU) blocks. The DG model was found to correctly predict the grade tonnage relationships for a wide range of cut off grades. The experimental test indicated that, given a representative histogram and variogram, the DG change of support provides a computationally efficient and practical means of reliably assessing global mineable resources at the early stages of a mining project. Further, it allows a range of selectivity strategies to be meaningfully and comparatively considered prior to mining.

Jan 1, 1995