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This paper explores the use of a Process Safety Management (PSM) system to manage risk in the mineral processing and metallurgical refining industries. Important elements of a PSM system are described. International regulations and non-regulatory guidelines covering PSM for high hazard industries are reviewed. Case studies of incidents in the mineral processing and metallurgical refining industries are presented to understand the lessons learned from failure to manage risks using a PSM system. Conclusions are drawn to adopt PSM in the minerals and metals processing industry as a tool for loss prevention and risk management.

Jan 1, 2003

Esso-BHP have installed a Production Supervisory Control System that is presently controlling the offshore oil and gas facilities on the Barracouta and Marlin platforms from an onshore master station. This control is achieved with a computerized master station onshore which uses a UHF radio system for telemetry and control. The system is designed to control, monitor, and gather data from a large number of oil and gas production platforms and has flexability to handle future variations in operating conditions. Thn -etom ..ill kn nvt,,ndnd to thn I-lalihn+ rJ,+f, rr , Into +hie -- -A +n the lei...,fieh .,lo+fnrmc A.,;- 1071

Jan 1, 1970

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

By H J. Ross, R K. Beatson, T J, W R. Fright

Traditional method of explicitly defining three-dimensional (3D) ore-waste and geological boundaries relies heavily on a time-consuming process of manual digitisation. This method of modelling can be best described as surface modelling, as complex surface geometry is built up by digitising points that lie on the surface. With the advent of fast 3D interpolation methods, however, construction of geological surfaces using volume functions is now a practical alternative to explicit modelling of surfaces. Unlike explicit modelling, surfaces contained in volume functions are not explicitly defined or digitised. Instead the existence of surfaces in the volume function is implicit, thus the process of modelling surfaces from volume function is called æimplicit modellingÆ. Based on recent advances in fast scattered data interpolation methods, implicit modelling first defines a continuous three-dimensional function that describes the grade or rock distribution. This volumetric function is interrogated for a grade value, or a geological surface, thus allowing the extraction of the 3D object to be automated and eliminating the need to manually digitise surfaces. Since the function is continuous throughout space and does not depend on a mesh or grid for its definition, the extracted geological or grade wireframes can be constructed at any desired resolution in the specific volume of interest. The volume modelling method can work on scattered drillhole data of any data density, including processing combined information from dense grade control data as well as sparse resource drilling. It offers distinct advantages over surface modelling, including: being able to wireframe geological objects that may take days to digitise in tens of minutes; substantial improvement in modelling accuracy; and the ability to generate conditional models rapidly allowing mining risks inherent in geological modelling to be examined.

Jan 1, 2003

By K L. Olzard

At the WMC Resources Phosphate Hill operation, monitoring the quality of the ore delivered by the mine to the beneficiation plant is of prime importance to ensure the fertilizer is produced cost-effectively through the various stages of production and meets customer quality requirements. P2O5 and Fe2O3 are among the critical-to-quality elements. Fe2O3 is a key performance driver as it is an impurity that adversely impacts some of the chemical processes. The ore is supplied to the plant on a conveyor belt that is equipped with an automatic sampler. Increments are taken off the flowing ore stream at regular time intervals. A variographic experiment was conducted to investigate sampling strategies capable of estimating ore properties over a 12-hour shift to a nominated level of precision. The combination of individual increments into a shift composite was included among the strategies that were assessed. The experiment involved collecting data at regular time intervals and preparing variograms to characterise the feed-grade variability on the conveyor belt. Duplicates were also collected to assist in quantifying the precision of the subsampling stages of the sampling protocol and assay accuracy was monitored with matrix-matched standards. Various sampling schemes were evaluated by combining geostatistical techniques and the sampling theory of Pierre Gy. The following parameters were varied: the number of increments, the increment-size reduction leading to the composite, the masses of the subsequent sampling stages and the number of analytical determinations. This paper describes the planning of the variogram experiment, the various phases of data collection and the methodology used to process the data. It discusses the development of some of the sampling schemes that were considered.

Jan 1, 2005

By A R. Gerson

Pyrite, chalcopyrite and mixed sulfide samples, with and without quartz (5 wt per cent S), were subjected to column leaching to mimic natural weathering (cyclic wetting and drying). The pH and SO4 2- concentration of the column effluent was measured over a period of 78 weeks. The pH of the pyrite-only containing column rapidly decreased and remained under pH 4 after 12 weeks of leaching. The pH calculated assuming a 2:1 ratio of H + generation and SO4 2- release was slightly lower than that measured. However, a reduced H + to SO4 2- ratio of 1:1 is predicted if the release of aqueous Fe 2+ is assumed rather than the formation of Fe(OH)3. The pH of all columns containing only chalcopyrite or a 1:1 mole ratio of chalcopyrite and pyrite remained at or above pH 5 for the duration of the leach even though significant SO4 2- was released. One column containing the same initial surface area of pyrite and chalcopyrite but only approximately 0.10 the mole fraction of S as chalcopyrite maintained a pH of greater than five for the first 56 weeks of leaching and showed sporadic acid production thereafter. It is well established that oxidation of chalcopyrite results in a surface layer of polysulfide material. It is the formation of polysulfide that neutralises the acid produced on S oxidation through to SO4 2-. Hence where polysulfide formation occurs extensively on chalcopyrite the resulting solution pH decrease will be less than that based on SO4 2- production. The oxidation rate of sulfide minerals increases with decreasing pH and hence acid formation via sulfide oxidation to SO4 2- causes the subsequent oxidation rate to increase. The addition of calcite (CaCO3)to a pyrite column not only neutralises the acid formed but also decreases the rate of release of sulfate to solution by a factor of approximately 30. This is also the case where chalcopyrite is present mixed with pyrite. The rate of release of sulfate from the mixed sulfide mineral columns (after the initial release of the sulfate already present) was between one-fifth and one-tenth that in the absence of chalcopyrite.

Jan 1, 2003

Mine planning typically involves designing an operation to uncover coal with the minimum initial costs with reclamation planning and earthworks being done as an "add on" task. The landform is too steep to remain stable, has no drainage and frequently has areas of excessive acidity or alkalinity. Extensive earthworks are required to reduce grades to an acceptable level and create a drainage system. The flexibility available to the mining engineer to alter the post mining landscape clearly depends on the mining methods. Straight dragline stripping provides virtually no flexibility. However most mining operations over the term of current ten year plans have a substantial pre-strip component. It is this pre-strip material which has the potential to reduce the final reshaping earthworks. The reshaping operation itself is subject to some flexibility with various options being available to re-grade and provide drainage. The full utilisation of this flexibility to minimise earthworks cost should be the aim of reclamation design. ACIRL's current thrust in reclamation is aimed at the integration of mine planning and reclamation earthworks. This involves gathering all environment and agricultural criteria and designing the earth works necessary to produce an acceptable final landform. A key component of our work is the use of computer aided design (CADD) for the design of spoil piles, pre-strip dumps and spoil re-shaping. This approach has been applied to a number of mine sites with earthworks operations covering hundreds of hectares and hundreds of millions of cubic metres volume. We are continuing to provide that consultancy service and at the same time are involved in the development of more sophisticated software tools to apply to reclamation design.

Jan 1, 1991

By O Salisbury

Ingress of air into the longwall goaf environment needs to be managed appropriately to reduce the risk of creating a spontaneous combustion event. The maingate goaf edge is an area of particular concern in this respect, as air often penetrates for some distance into the goaf along this region inbye of the longwall face. Since the flow rate in this part of the goaf is also quite low, an opportunity exists to disrupt the air pathway by implementing a barrier to the airflow. Previous attempts using plugs made from an assortment of materials have resulted in varying degrees of success. More recently, Narrabri Coal Operations (NCO) has introduced the use of a chemical foam that is mixed with nitrogen to produce a standing barrier with the consistency of shaving cream. The implementation of this practice has consistently proven to be very effective for reducing the oxygen concentration along the maingate goaf edge by systematically retreating the foaming unit with the longwall. This paper presents how the foam is applied in the underground goaf environment to prevent oxygen ingress and uses results from gas monitoring to confirm the foam effectiveness.

Oct 12, 2022

By Taylor GP

Mt Kasi in Fiji is a high sulphidation style of gold deposit exposed at a high crustal level. Individual alteration centres are localised at the intersection of cross structures within a through-going structural corridor, the Mt Kasi Fault System. A two stage alteration/ mineralisation model suggests that much of the high sulphidation alteration is derived from the initial rapidly moving gas-rich portion of the hydrothermal fluid. The gradual cooling and neut-ralisation of hot acid fluids by mixing with oxygenated ground waters forms the characteristic zoned alteration assem-blages which grade from cores of residual silica through silica-alunite to peripheral clays. The liquid-dominated phase of the hydrothermal fluid brecciates the competent, altered rocks and deposits sulphide mineralise-ation within the breccia matrix. High gold grades occur in the matrix-rich breccias and decline from the hydro-thermal fluid upflow to outflow zones.CSAMT (controlled-source audio magneto-tellurics) geophysics has been used to define the geometry of the alteration centres while strike slip movement on the major structures accounts for the dilational structural environment in which the ore hosting breccias form.

Jan 1, 1994

By K Jupp, T J. Howard

Cliffs Natural Resources Pty Ltd (CNR) operates iron ore mines in the Koolyanobbing region of Western Australia. Ore is mined from three locations, separated by many kilometres. The ore is stockpiled at these locations, according to an in-house ore classification system (based on grade and source) and then trucked to the crushing and screening plant at Koolyanobbing. Lump and fines products are railed to Esperance for ship loading and export to Asian customers. CNR prides itself on the relatively low inter-shipment grade variability of the products. The Koolyanobbing crusher is fed using a daily blend plan, generated to maintain lump and fines product grades within acceptable tolerance ranges around targets. Achieving low variability requires predicting lump and fines grades as accurately as practical from the estimated head grades of the ROM ores potentially going into the blend. The grade prediction model may be either a direct prediction of crushed lump and fines grades and lump percentage, or be split into two stages: the bias between blasthole estimated head grade and crusher head grade and then the lump-fines algorithm for splitting the head grade between lump and fines products. The lump-fines algorithm comprises the percentage of lump and the difference between the lump and fines grades. We describe a weighted least squares (WLS) regression model for predicting crusher grades and lump proportion from the estimated head grade for Fe, P, SiO2, Al2O3, Mn and S. The method is applied to CNR production data, where the regression model explains approximately 60 per cent of the variance in the crushed ore grade, for both lump and fines. A further small but significant improvement in prediction can be achieved by including the ore classification data in the model. The regression errors exhibit strong positive serial correlation, indicating trends in grade error across multiple blend records. To compensate for the longer-term error, an exponentially smoothed model was developed and applied to the daily grade blend errors. This gave an increase in the longer-term variance explained and therefore an improvement in grade prediction.

Jan 1, 2009

By S-C Shim, H-R Lee, Y Kang, H Shin

Since iron oxide and silicon oxide are major gangue components in various types of ore, FeO-SiO2 base slag, ie fayalite slag, has been often encountered in pyrometallurgical processes of non-ferrous metals. During most matte production processes such as the smelting of Cu, Pb, and Ni, the FeOSiO2 based slag is inevitably formed and plays an important role in refining crude metal as well as engineering aspects. Recently, similar pyrometallurgical approaches have been attempted in the recovery of valuable metals (Ni, Co, Cr) from wasted secondary batteries. Thus, the viscosity of the FeO-SiO2 based slag has great significance in properly controlling smelting processes. However, when molten metal or matte does not coexist with the slag during the measurement, there has been a serious difficulty in maintaining Fe valance and consequently, the slag composition. In the present research, the viscosity of molten FeO-SiO2 slag was measured in 1573~1673 K using a rotational viscometer. In order to keep the state of iron oxides, the oxygen partial pressure was controlled using CO/CO2 gas mixture. The optimised ratio of CO/CO2 could be calculated using Fe/Fe2+ and Fe2+/Fe3+ equilibria at each temperature. The composition of the slag, particularly Fe valance, after the measurement was analysed with the aid of an inductively coupled plasma – optical emission spectroscopy (ICP-OES) and an automatic potentiometric titrator. The measurement showed that the FeO-SiO2 slag has considerably low viscosity values in the molten state, and it sharply increases as the temperature decreases. In spite of the careful oxygen partial pressure control, a part of Fe2+ was found to be oxidised to Fe3+, with a maximal case reaching about 20 per cent. The increase in viscosity of FeO-SiO2 at low temperatures can be attributed to the composition change due to an unavoidable Fe2+ oxidation. In addition, the relationship between the change in the viscosity and the liquidus temperature of FeO-SiO2 based slag was discussed to understand the composition dependence of viscosity.

Jun 19, 2024

By Garg R. K

Himalayan ranges on the northern border of India are source of many perennial rivers and suitable sites for large dams have been located therein. However, Himalayas are young mountains and comprise of comparatively weaker rocks having adverse geological features like shear seams, thrust zones, minor and major faults and intense jointing. Tehri dam project under construction, is located in lower Himalayas. It envisages construction of a 260.5 m high earth and rock fill dam and an underground power station of 2000 MW (Eight machines of 250 MW each, four of which will be reversible) installed capacity. This dam will be the highest and the underground complex will be the largest to be constructed in India in the Himalayas. The under- ground complex comprises of 25 km of tunnels varying in diameter from 6 m to 11 m and seven large cavities of various sizes, the biggest being 22 m in width, 194 m in length and 65 m in height. Rock formation in the power house complex belong to phyllites having various joint sets spaced from 0.5 m to 3 m. Due to the poor geological conditions and closely spaced net work of large cavities, the planning, analysis and design of the cavities is a challenging job. Many aspects have to be considered in determining the sizes, locations and orientations of the various cavities taking into account the properties and jointing pattern of rock mass, functional requirements and economics. Correct evaluation of loads and forces is necessary for economical design of supporting system for the various cavities. Rock loads on the roof of cavities and their supporting system will be assessed with the help of the latest methods. The stability of the rock mass around the cavity will be evaluated by elasto- plastic method using finite or boundary element techniques. A scheme of field investigations, laboratory tests and instrumentation for deter- mining rock properties in preconstruction stage and for monitoring behaviour of the underground cavities during and after construction is envisaged.

Jan 1, 1987

By E R. Ramanaidou, M Wells

The aim of this paper is to summarise all known Phanerozoic ooidal ironstone deposits worldwide, including Australian deposits such as the well-known channel iron deposits (CID). Nearly 400 occurrences have been catalogued based on stratigraphy, geographical coordinates, facies, grade, tonnage and iron bearing ore minerals. The description also includes details on the geochemistry, genetic models and main references. Brief statistical analysis provides an overview of the variation between these deposits. This compilation offers a basis for better understanding of the ooidal ironstone deposits and a global evaluation of this important resource worldwide.

Jan 1, 2009

The movements of the major continental cratons and the distribution of the principal tectonostratigraphic terranes are reviewed in the Circum-Pacific region during Phanerozoic time. It is concluded that major periods of orogeny and consolidation of accreted terranes in the Circum-Pacific region is best correlated with periods of advance of cratonic blocks over the Pacific Ocean basin combined with relative convergent to transpressive motions between the cratons and the Pacific Ocean plates. Continental collisions and collision of terranes with continental margins has not been a significant geodynamic process in Circum-Pacific tectonic evolution. The permanency of the Pacific Ocean basin throughout 500 MA is remarkable. It appears no continental block or large continental fragment has ever entered or crossed the Pacific Ocean basin since early Paleozoic time. This area where no continent has entered for 500 MA is almost coincident with the present Pacific Ocean basin and seems associated with the 25 to 100 meter geoid high which dominates the present-day figure of the Earth.

Jan 1, 1990

By B McFadzean, N P. Lima, D A. Deglon

The reverse flotation of Itabirite iron ore is typically performed after a desliming step in which most of the sub-10 µm particles are removed. This is done to limit processing problems such as poor flotation recovery of SiO2 due to slime coatings and increased slurry viscosities, unmanageable froths and increased losses of hematite particles due to entrainment. However, the rejection of ultrafine particles contributes to large losses in iron recovery and may contribute to the instability of tailings dams. The aim of this study is to decouple the effects of ultrafine particles in the pulp and froth phases to better understand the processing capabilities of the fines fraction. The flotation test work was performed in a special-purpose continuously operated laboratory flotation cell that has a deep froth section to simulate plant-scale froth conditions. Five conditions of fines addition were investigated at three different froth heights and a solids concentration of 50 per cent. The behaviour of the pulp and the froth were decoupled using froth stability and froth recovery tests. This showed that, even though there is an exponential increase in froth stability at increasing fines quantities, the performance of the pulp has the overriding effect on the overall SiO2 recovery. Pulp zone, froth zone and overall SiO2 recoveries showed that overall recoveries increased by about 3.6 per cent for every 1 per cent decrease in fines content. This meant a large increase of 20 per cent in SiO2 recovery when going from undeslimed to deslimed feed. This was driven largely by increases in the pulp zone recoveries, which were about 4 per cent for every 1 per cent decrease in fines content. The froth recoveries, on the other hand, decreased by between 0.75 per cent and 2.5 per cent for every 1 per cent decrease in fines content, depending on froth height. This paper explores further insights into iron ore flotation processing at different slimes concentrations.

Aug 24, 2022

By D Kent

"There has been a revolution occurring in underground mining over the last several years, where big headline items such as the Internet of Things (IoT), optimisation, managing data, data mining etc – the list of current catchphrases, goes on. In the end these are nothing new; but the ‘things’ (sensors) are becoming smaller, cheaper and easier to deploy, and the analysis much more powerful as computer processing speeds increase. However, to take advantage of the myriad of devices out there and gain the processing power to analyse and use the data, a reliable ‘conduit’ is needed for that information to be delivered where it can actually be used. That is, a high quality data network.Modern mining is like any other industry in the information age: the access to reliable data is the first, critical step in improving productivity (Stevens, 2015). The convergence of communications onto an IP (Internet Protocol) backbone has been the driving force in enabling the productivity gains in general industry over the last two decades.This paper overviews how this technology has developed as an enabler in accessing productivity and safety benefits, and how it has used access to large amounts of data to manage mining processes underground. Reams of data are useless, but with the reliable receipt, analysis, processing and feedback system in place to use that data, benefits can be realised.Automated mining systems are increasingly being seen as a key requirement for a productive mining operation, and the importance of an integrated communication network infrastructure to support such systems is growing. Another emerging driver is the much talked about IoT and data analytics, both dependant on reliable, accurate, high volume data.The author will outline how communication infrastructure is fundamental to the operation of such systems, and explain why the resultant communication networks require much more than just increased bandwidth (data capacity) to properly support the automation and other data hungry systems within the overall mine operation.Mining operations embarking down this road are discovering that the required network must be based on a true enterprise level architecture to, not only enable the mine’s current plans for remote or automated mining, but also to provide a scalable and integrated platform for future developments. The emerging issues for the communication network to truly support automation systems include: increased complexities of operating and maintaining multiple networks integration issues with disparate systems problems with reporting, particularly as demands for corporate reporting and compatibility with enterprise systems become the norm ongoing management challenges, which will only increase with the proliferation of new technologies.How certain mining operations lay the necessary foundations to meet their current requirements, while supporting their visions for a more automated and proactively managed mine, will be explored.CITATION:Kent, D, 2017. Modern mining – why bandwidth matters, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 123–128 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

This paper examines the latest advances in mine drive and motor systems. In the last decade, the drive technology employed for large mine winders has migrated from the traditional dc technology to ac motors with cyclo convertor drives. Recent advances in pulse width modulation (PWM) drives have resulted in these being applied to large winder drives. While having many advantages for the winder system, the PWM drive must be carefully designed to ensure long-term reliable operation. When combined with induction motor technology, the PWM drive presents the ideal solution for winder drives. This paper examines the factors in choosing a suitable PWM drive for a winder installation. Factors under consideration include: winder duty cycle, drive rating restrictions, choice of power semiconductor device, cooling, and low speed operation.The cage induction motor is the motor of choice for large winder drives and has a number of advantages over the synchronous motor. The induction motor is ideally suited to integrated winder applications where the motor is built inside the friction drum, as installed at WMCÆs Olympic Dam site. The challenges of integrating the induction motor into the friction drum will be detailed, including: assembly, ventilation, air gap adjustment, and position sensors.

Jan 1, 2005

By X Yang

White phosphorus (P4) is a critical element in industry, but its current production from phosphate rock using the carbothermal reduction method raises significant environmental and health concerns. This pressing issue necessitates the development of new technologies that facilitate the sustainable production of P4. In response, my team is actively developing an innovative, coke-free approach for white phosphorus production. This method involves the dissolution of phosphate rock in molten CaCl2, followed by the extraction of P4 through electrochemistry at relatively low temperatures. Moreover, this approach has the potential to utilise phosphate-bearing solid wastes as raw materials, further enhancing its environmental benefits. By employing this cutting-edge technique, we aim to revolutionise the phosphorus chemical industry towards greener and more sustainable practices. This paper provides evidence of the feasibility and effectiveness of our proposed approach.

Aug 21, 2024

By J Rowland

"This paper was primarily put together in order to demonstrate what are believed to be acceptablestandards, in relation to ventilation surveys and the subsequent model assembly process. Thiswas brought about by the fact that in many parts of the world it is regarded as acceptable to carryout ventilation surveys and then build and supply the client with a æstick fi gureÆ type ventilationmodel. Such stick models have arguably litt le use and a very short life span in the real world and isalmost impossible for site staff to maintain. Thankfully most underground coal mines in Australia strive to maintain a true replica model of their ventilation circuits and to keep them in a relatively good state. Given that these mines own and maintain the models, it is often seen as necessary to update or rebuild them. The level of survey detail required to do so is totally dependent on the end use of the data and the criticality of the accuracy of the data set, to the ongoing safety and viability of the business. Mine technical personnel should think clearly about the use and importance of the ventilation survey and subsequent report outputs required that will help them bett er understand their mines and bett er prepare them to manage their ventilation circuits, on an ongoing basis. This paper provides some guidance for Australian ventilation engineers so they may plan and execute this work æin houseÆ, should they rightly choose to do so. To this end, methods of data collection and circuit analysis required for surveys of a high order of accuracy are detailed. Also, some of the issues which are important when formulating a strategy to carry out the appropriate ventilation survey for the required purpose are summarised. As well, the major details that should be furnished within any survey and some survey/report outputs and/or omissions, which are clearly not acceptable, are highlighted."

Jun 1, 2012

By Misra A

After review of the status of research on optirnisation of retreat longwall faces it is argued that an acceptable optimisation model must be based upon realistic cost data that take into account not only the face costs, but the total panel costs. These include the cost of development, face cost, removal and installation cost. The determined optimum length of a retreat longwall face is based upon a realistic model and actual costs.Parameters that influence the optimum face length have been varied over wide limits to allow determination of the sensitivity of the model and the effect of the parameters on the optimum face length. It is concluded that for medium production rates and medium system availability, the optimum face length of a retreat longwall face under Australian conditions lies between 180 and 220 metres.

Jan 1, 1995