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By D Giles, A C. Bailey

In the first 20 years of the 21st century, just over 20 per cent of Australian mineral exploration expenditure was dedicated to iron ore, totalling >A$8 billion and >30 million metres of drilling (Australian Bureau of Statistics, 2021). Improvements in the cost, efficiency, safety, reliability and data quality of drilling have the potential to deliver significant productivity improvements, increasing the probability of discovery and reducing the time from discovery to mining. Currently in its third year of research, Mineral Exploration Cooperative Research Centre (MinEx CRC) is focused on a new set of exploration tools and new ways to deploy those tools which recognise the fundamental importance of collecting quantity and quality data from the subsurface, to enable exploration success for all minerals, including iron ore. MinEx CRC is focused on developing more productive, safer and environmentally friendly drilling methods to discover and drill-out deposits. This includes pioneering work on Coil Tube (CT) drilling technology and innovations in Diamond and Reverse Circulation (RC) drilling techniques aimed at improved drilling optimisation and automation. In parallel, MinEx is developing new technologies for collecting data whilst drilling. This is being undertaken in four separate industry-led projects utilising geophysical, seismic, downhole analytical and 3-dimensional (3D) modelling improvements. A National Drilling Initiative (NDI) is also underway, with two drilling programs completed in 2020. The NDI is a world-first collaboration of Geological Surveys, researchers and industry, which undertakes drilling in under-explored areas of potential mineral wealth in Australia and provides a test-bed for new mineral exploration technologies.

Nov 8, 2021

By S Bright, M J. Masamvu, E K. Chiwandika, S Dandi, S M. Masuka

The depletion of high-grade hard and lumpy chrome ores has forced Zimbabwean ferrochrome producers to resort to low-grade friable ores that have an average of 28 per cent fines against a set limit of 12 per cent. Submerged open arc furnaces currently in use are associated with eruptions within the furnace because of the high amounts of fines, high energy consumption, as well as high SO2 and CO2 emissions. Traditionally employed agglomeration methods such as pelletising and the use of coke in the furnace have been discarded because of the pressure to lower operational costs and to achieve higher profit margins. This research aims to develop a method to incorporate lowgrade friable ore fines and unprocessed coal into production while lowering CO2 and SO2 emissions through a closed direct current (DC) arc furnace. The closed DC arc furnace could incorporate the friable ores and coal while maintaining above 90 per cent reduction rates. Preliminary findings also show that energy consumption could be reduced by up to 35 per cent by incorporating a pre-heating and pre-reduction system using the flue gases from the furnace. In the proposed circuit, the cost of production per ton of ferrochrome might be potentially lowered by an average of 30 per cent.

Jun 19, 2024

By D Ray, D Brett

A clay-capping trial was established in 1996 on Magazine Dump at the Mt Lyell Copper Mine. The trial was initially constructed under the Mount Lyell Remediation Research and Demonstration Program, a co-operative venture between the State and Federal governments. The detailed engineering design for the clay cover included the following features; reshaping and compaction of dump batters, 5 m vertical bench interval, overall side-slopes of 2.5:1, emplacement of clay in four 150 mm lifts, compaction by a 10 t vibrating roller or ætrack rollingÆ on batters with density testing for quality control. A small section at the base of the dump ( The trial also generated certain unexpected findings. Field permeability tests on the cover yielded uncertain results and oxygen remains available throughout the dump. The flow data indicate that, while total outflow has decreased as a result of storm shedding, inputs from groundwater and batter infiltration are still significant. Outflow during the driest weeks of the year may have risen following capping. Detailed assessment of the data is hampered by insufficient pre-capping information; however, there is a possibility that conductivity flux emitted when flows in the receiving environment are at their annual minimum is unchanged or worse post-capping.

Jan 1, 2003

By S Pontual

Compact and field portable infrared spectrometers have been increasingly used over the past few years by an exploration industry constantly searching for a technological edge and the ability to more accurately and rapidly assess project areas. In particular, this technology allows large amounts of data to be rapidly collected on-site and sample mineralogy, mineral crystallinity and mineral composition to be quickly assessed. In recent years, short wave infrared (SWIR) reflectance spectroscopy has proved useful in a wide range of geological environments and at various stages of exploration programs, from grass roots reconnaissance through drilling programs and resource evaluation. Unfortunately these data have frequently been analysed and interpreted in isolation using time consuming data analysis techniques removed from the realities of a fast moving exploration industry. This paper presents new analysis techniques which allow these data to be efficiently integrated in the exploration program. Although SWIR data contain a wealth of mineral information it is impractical to use this information in its raw form. A more effective approach involves the extraction of key characteristics of these data (ie mineralogy, mineral composition and crystallinity) as numerical values, and the integration of this ædigital mineralogyÆ with more conventional exploration datasets (eg geochemistry, coordinate data, etc). This paper demonstrates that the integrated analysis of sound geological observations, geochemical, spatial and spectral data can quickly lead to a greater understanding of the nature and distribution of target mineralisation. As a first step, software driven pattern matching routines enable the identification of the major clay mineral species in a series of samples (eg kaolinite, montmorillonite and sericite). This allows the major alteration facies and their spatial distribution to be identified. Quantification of diagnostic absorption feature characteristics then allows more accurate determinations of mineralogy to be made (eg mineral composition and crystallinity). Examples of the application of SWIR analysis for alteration mapping from selected porphyry and epithermal systems from around the Pacific Rim are discussed. The data presented are derived from a variety of locations and sample types including drill core, ridge and spur rock chip samples, soil samples and geochemical pulps. In these large alteration systems, the spectral data can be used to describe and map the distribution of various alteration facies as many of these are characterised by clay and phyllosilicate mineral assemblages and are detected by SWIR analysis (eg smectite, chlorite, biotite, illite, muscovite, kaolinite, dickite, pyrophyllite, alunite, etc). In addition, the ability to evaluate even subtle trends in mineral crystallinity and composition is often vital in these systems when looking for vectors towards higher temperature parts of the system. In addition to detailed evaluation of mineralogy, the integration of digital mineralogy data with geochemical data leads to the ability to describe not only geochemically anomalous intersections or regions but also to recognise associations between subtle changes in mineralogy and target mineralisation. This is often important because understanding these mineralogical associations can lead to more accurate targeting and rapid assessment of the project.

Jan 1, 1999

Aitik, a Boliden owned and operated open pit mine located in northern Sweden, will expand production from 18 Mt per year today to 36 Mt per year copper ore during 2010. The challenge for the mine operation is to double production with a planned increase of the shovel and truck fleet of only 50 per cent. This will be achieved through improved shovel and truck utilisation and productivity. In early 2005 Aitik started projects to enhance the utilisation of truck engine hours and to reduce fuel consumption. Both projects were successful, within a year efficient2 utilisation of engine hours increased from 60 per cent to 75 per cent and fuel consumption was reduced by six to eight per cent. The truck utilisation project focused on minimising idle truck hours by for example four operators on three trucks thus reducing idle engine hours to minimise lost time for breaks and shift changes. Other measures included focusing on improved dispatch usage, parking trucks when overtrucked, etc. Eco-driving was a project together with Swedish Road Administration with the objective to combine economical and environmental savings. To keep the focus on eco-driving a reward was set up for the shift team with the lowest fuel rate over rolling 15 weeks periods. Both activities included a comprehensive training program for mine foremen, dispatchers and truck operators focusing on efficient use of trucks from economic driving to optimised truck dispatching and minimising idle engine hours. Online monitoring of trucks activities and fuel consumption combined with continuous reporting gave shift foremen and management a tool to discuss and follow trends and individual shift team performance. The combination of close monitoring of mainly organisational practices and operator training resulted in significant productivity increase and lower operating costs without any capital investments.

Jan 1, 2007

By I Manege, S M. Bennett

The PT Kaltim Prima Coal (KPC) operation is a large scale coalmine operating on the east coast of Kalimantan (Borneo), Indonesia. Originally developed under a coal contract of work (CCOW) with the Indonesian Government, new legislation has led to uncertainty as to the actual life of the mine, the size of the operating lease or mining area, the rehabilitation compliance requirements and other areas of concern. The actual life-of-mine (LOM) plan is therefore in a constant state of flux and must be updated and modified with every new piece of information.Under the CCOW system, the mine life ran from the first year of production (1992) for 30 years (2021), with the potential to extend for a further two ten-year periods. KPC has always intended to run until at least 2041. Under the new legislation, the potential term of the CCOW (to be replaced by a mining license) is open to interpretation, resulting in KPC having to prepare plans allowing for a LOM that may end in 2021, 2031, 2041 or a range of other possible periods of time.Uncertainty about legislation (and hence the mine life) possible production rates and available work areas; variable coal prices and costs; varying management contexts; the substantial reserves available; difficulty sourcing dump space; potential rehabilitation costs and the dependence of a community of over 100 000 people on a single operation sees the LOM and mine closure teams preparing dynamic yet thoroughly robust plans that are updated on multiple occasions per year.This paper will describe the procedure followed by KPC and the potentially show stopping issues that must be dealt with.CITATION:Bennett, S M and Manege, I, ?2014. Life-of-mine planning in a dynamic environment, in Proceedings Life-of-Mine 2014 , pp 379–388 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By H Ishikawa, H Zhou, M Spagnolo, R Halomoan, S Palaniandy

The Karara Mine concentrator commenced operation in November 2012 to produce high-grade magnetite concentrate. The circuit consists of three stages of comminution plus magnetic separation at each stage for early gangue rejection. High-Pressure Grinding Rolls (HPGRs) are used for fine crushing, followed by ball mills and TowerMills in secondary and fine grinding duties respectively. In recent times, the plant throughput rate has had to exceed design by 18% to maintain the targeted concentrate productivity. Meanwhile, the ore hardness has increased by 25% to 15 kWh/t, leading to changes in the circuit operation and design. These changes led to coarser and harder feed to the TowerMill circuit that affects the subsequent separation processes. Nippon Eirich (the TowerMill manufacturer) has partnered with Karara Mining Limited (Karara) to optimise the TowerMill circuit operation to achieve a circuit product with an 80% passing (P80) of 35 µm. Several activities, including a TowerMill circuit audit and performance evaluation, multi-component analysis, modelling and simulation, were carried out as part of the optimisation exercise. The circuit audit results revealed that the TowerMill circuit feed size F80 had increased and ranged from 67–75 µm. The circuit product P80 ranged between 42–55 µm. The average circuit specific energy was 3.4 kWh/t. Moreover, the differences in density between magnetite and gangue minerals had affected the hydrocyclone performance where the efficiency curve exhibits coarse end deflection indicating that low-density coarse material was bypassing to the overflow stream. A multi-component analysis was carried out to further investigate the coarse end deflection of the hydrocyclone efficiency curve. The analysis showed that the magnetite and gangue minerals had different cut sizes of 32 and 64 µm respectively. Furthermore, 33% of the magnetite (below 35 µm) was being recycled back to the mill due to the density effect. Based on these findings, several recommendations for process improvement were identified and implemented including:• converting to a bottom feeding configuration to improve the grinding efficiency in the mill• additional grinding power in the fine grinding duty to compensate for the increase in plant throughput and ore hardness• improved classification efficiency by converting to smaller size hydrocyclones. Simulation studies carried out to evaluate the impact of these implementations had indicated that a P80 close to 35 µm with a steeper size distribution could be achieved by using the bottom feed configuration with additional grinding power. The TowerMill circuit was converted to bottom feed configuration and the performance was evaluated. The operating work index, size specific energy and circulating load were 30% lower than the top feed configuration, indicating that the bottom feed configuration had a higher grinding efficiency. This paper discusses the outcome of the circuit audit, multicomponent analysis, circuit simulations, improvement strategies and quantification of the improvements. CITATION:Palaniandy, S, Spagnolo, M, Halomoan, R, Zhou, H and Ishikawa, H, 2017. Fine grinding circuit process improvement at the Karara mine concentrator, in Proceedings MetPlant 2017, pp 101–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By P V. A van der Westhuyzen

Namakwa Sands is a heavy minerals mining and beneficiation business in the Exxaro Sands Division, and operates along the West Coast of South Africa (see Figure 1). The business encompasses mining, mineral concentration, separation, and smelting operations. Inflated commodity prices and increasing operating costs demands greater attention to the management of process performance and the company wide coordination of resources. Consequently, the task of deploying operational/technical skills and budgets into the most appropriate parts of the business assumes great importance in order to increase productivity from its capital assets. The mineral sands industry is under the same sort of economic scrutiny that all other industries find themselves, and as such, Exxaro – Namakwa Sands has taken the strategic initiative to improve overall resource utilisation within the processing steps and to measure the costs associated with obtaining this value.This paper provides details of the successful implementation of a Kelsey Centrifugal Jig (KCJ) at Namakwa Sands to recover primary and secondary zircon products from the wet gravity (quartz) rejects generated and stockpiled at the Mineral Separation plant (MSP).

Oct 5, 2011

By M Kuruppu

Large mining operations require a high percentage of the capital invested in mobile and fixed mining machinery. From an investment point of view this expenditure must be met by an equally high rate of return, thus the need for high plant and equipment reliability is of major importance. Equipment downtime is undesirable and very costly, resulting in lost production and revenue, which is of critical importance to successful mining operations. One of the solutions to this problem may be found in the form of competent computerised maintenance management software systems, which help to reduce the problem of breakdowns. These software assist the engineers for the management of service orders, resource allocation, progress monitoring as well as costing. They also facilitate the communication of targets and objectives among the service personnel. A computerised maintenance management software called MAINPAC was used to record and plan the activities of mobile equipment maintenance in a large mining operation in Western Australia. Among the details recorded were equipment data, service history, machine downtimes, previous maintenance, job planning and the resource required. This information further helped to analyse the maintenance efficiency, availability and the reliability of the equipment.

Jan 1, 2006

By A R. Penney

Safety management, both personal and that associated with catastrophic hazard, helps to define the success of mining companies. Personal safety management, often categorised by slips, trips and falls, has been widely addressed, with numerous approaches successfully adopted. Catastrophic hazard can lead to a single accident (eg ground collapse, underground fires etc) causing multiple fatalities. Catastrophic hazard management in mining is an emerging discipline, and as such there are various pitfalls to demonstrate its effectiveness and success; it is much more than simply meeting regulatory requirements. Various standards, guidelines, and leading practices are available for reporting key performance indicators. While measuring and reporting safety related key performance indicators (KPIs) such as Total Recordable Injury Frequency Rate (TRIFR), Lost Time Injury Frequency Rate (LTIFR), are important, they often lack detail, and give little insight into the effectiveness of catastrophic hazard management strategies and controls. Catastrophic hazards are low likelihood, high consequence events, and as such demand a different management approach. Companies cannot use the suite of personal safety metrics to help demonstrate management of catastrophic hazards. In-field verifications have revealed that senior management commitment to safety is often clear, well organised, and resourced. However, there are often some inconsistencies between what management promotes and plan, to what the operational teams understand and implement. Communication and clear understanding of expectations were the common themes identified to help empower supervisors to reinforce requirements of catastrophic hazard management. A lack of specific, measurable, and time-sensitive goals and objectives for the short- or medium-term, making it challenging to track progress was another key observation. Development of an integrated, multi-disciplinary auditing process executed by an experienced team of technical subject matter experts, provided an in-depth understanding of the requirements of catastrophic hazard management. Areas such as underground fire prevention, explosive storage, electrical safety, mobile vehicle interactions, ground control, inrush, and shafts and winders management have substantial overlap and intertwined processes, and similar strategies for emergency responses. Auditing of catastrophic hazards and safety management systems compliance is only the first step in safety assurance. Completing operational performance audits in technical areas and benchmarking the site verification of safety management documents and verifications forms a critical part to clearly demonstrate industry leading safety practices. No longer is it the external inspection or regular hazard management plan review requirements that dominate, but rather the culture of continual hazard identification, management, controls verification, underpinned by improvement and follow-up verifications of the corrective actions.

Mar 29, 2023

By I A. Lamb

The Melbourne City Link Project has two tunnels, the Domain and Burnley Tunnels, which have been constructed by Transfield Obayashi Joint Venture (TOJV) under a design and construct contract. The two tunnels are located essentially under the Kings Domain, the Yarra River and, in the case of the longer Burnley Tunnel, under the inner suburb of Richmond. The Burnley Tunnel is 3.5 km long and reaches a depth of 65 m at the central Swan Street Shaft, the invert being at RL -60 m. The Domain Tunnel is 1.6 km long, with the invert reaching RL -20. The tunnels were driven, for the most part, in the siltstone and sandstone of the Silurian Age Melbourne Formation. Construction aspects of the driven tunnels as related to the engineering geology have been described by Hutchison et al (1998). The Silurian bedrock is a fractured rock aquifer that is connected to overlying alluvial aquifers. Excavation of the tunnels allowed temporary groundwater inflows which substantially de-pressurised portions of the various aquifers. This de-pressurisation provided the potential to accelerate on-going secondary consolidation rates of the Holocene Aged Coode Island Silt (CIS) and the older Quaternary Fishermens Bend Silt (FBS) deposits, in areas where these materials directly overly the aquifers. As a large portion of the urban area of South Melbourne and the old river course of the Yarra River contain extensive CIS deposits, and were within the drawdown influence of the tunnels, the management of the hydrogeological regime was very important. The permanent design of the tunnels comprised drained and undrained sections (a partially tanked design) which, along with some permanent recharge, provide long-term protection against the possibility of accelerated settlement rates. During construction TOJV implemented a comprehensive groundwater management plan to deal with issues related to the temporary drawdown of the aquifers and the temporary acceleration of settlement. This paper describes the hydrogeological regime, the effects of the tunnelling, the monitoring programs, the extensive temporary recharge system, and the consultation program that TOJV utilised to manage the hydrogeological issues.

Jan 1, 1999

By N Petropoulos and M J Thurley, E Righetti, M Wimmer

Fragmentation in sublevel caving (SLC) is vitally important. Both gravity flow and any downstream processes are affected. Reasonably coarse fragmentation may lead to larger draw bodies (isolated extraction zones) and hence potentially higher primary ore recovery and depressed/delayed waste rock inflow from above. Fewer flow disturbances are expected by mitigating oversize. In addition, it requires less boulder handling and reduces wear and possible hang-up problems in orepasses. To assess the present-day functionality of large-scale SLC, a multiyear, comprehensive measurement program was initiated. It covers the main elements for SLC, namely blast function, fragmentation and gravity flow. The present paper focuses on fragmentation measurements. An image acquisition system was used to document the drawpoint and the load-haul-dump (LHD) bucket for each mucking cycle. At the beginning, four buckets (about 70 t total) were sieved to validate the results of both 2D and 3D image analysis techniques. The fundamental and specific problems are discussed herein. At the moment, fragmentation of the SLC rings is evaluated using a quick rating system and a 2D fragment delineation software. The results enable a description of fragmentation and its variation during mucking but also – combined with the gravity flow measurements – conclusions on the fragmentation for different parts of the SLC ring. Possible influences on flow disturbances and ore recovery/dilution are investigated. The recent findings allow a better understanding of breakage and flow and support future process improvements.CITATION:Wimmer, M, Nordqvist, A, Righetti, E, Petropoulos, N and Thurley, M J, 2015. Analysis of rock fragmentation and its effect on gravity flow at the Kiruna sublevel caving mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 775–792 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Late Cretaceous and early Tertiary coals in the Greymouth, Ohai and Kaitangata coalfields represent a major national energy resource comprising-up to 2500 x 106 tonnes of coal in ground. The three coalfields are closely related in terms of age and sedimentary and structural character. The most striking feature common to all is the complexity of the geology which has severely restricted exploration and mining of these coal resources. This complexity is manifest in the irregular lensoid nature of coal seams and by the incidence of unpredictable medium and small scale faulting and folding. There are many geological similarities between these coalfields which are considered to arise from a common origin which can be related to the plate tectonic evolution of the southwest Pacific region. In order to efficiently assess and exploit these coal resources it will be necessary to know their geology in great detail. This can he achieved by increasing the understanding of the sedimentary and structural evolution of the coal bearing basins. This knowledge may be gained by the application of traditional (ie drilling, field mapping) and innovative techniques (ie high resolution seismic, in seam seismic) with on going research-oriented studies (ie basin analysis, coal petrography).

Jan 1, 1987

By Fowke NC, Williams RJ, Hungerford F

In-seam, directional drilling has been implemented at Huntly West Mine, New Zealand as the most cost effective means of obtaining geological information at a level of detail and accuracy required for planning of longwall ("flexiwall") panels. No geological or geophysical technique tried at the mine prior to 1989 has been able to reduce geological risk to an acceptable level. Surface and in-seam seismic methods have not had adequate resolution. Obtaining the required knowledge via surface drilling would be prohibitively costly, and still not precisely locate or orient faults or the axes of seam "ridges and valleys".A total of 3543 m was drilled at an average of 67m/shift including setting up time. Unplanned delays totalled only 9.6 percent. Major re-interpretation of seam structure resulted from the drilling. Lateral and longitudinal panel grades have been defined. which should be negotiable with the Coalcorp longwall equipment.

Jan 1, 1991

Base metal skarns have provided most of South KoreaÆs Pb-Zn production since the end of the Korean War, with the bulk of production coming from the Yeonwha group of mines. Currently only the Kumho Zn-Pb mine remains in production, while magnetite skarns are mined as iron ore at the old Yomisan and Ulsan base metal deposits. Base metal skarns within Korea fall into two groups; those hosted in Cambro-Ordovician limestone sequences, situated mainly in sub-basins in the northeast of the peninsula and those hosted within carbonate volcaniclastics of the Cretaceous Gyeongsang Basin, in the southeast. Sulphide mineralisation is dominated by sphalerite, lesser galena, arsenopyrite and pyrrhotite, with subordinate chalcopyrite and molybdenite with Ag-Co credits. Skarns are composed of pyroxene-clinopyroxene-garnet-carbonate-quartz and magnetite, grading into silica-chlorite hornfels. Most of the significant deposits display both pipe-like and stratabound morphology. In the Hwanggang district, a zoned distribution of Ordovician carbonate hosted, polymetallic Mo-W and Zn-Pb-Cu-Ag base metal deposits is observed around the margin of a Cretaceous granite intrusion. Similar polymetallic zoning is recognised in the Sangdong district, where deposits include Sangdong (W), Abisan (Au-As) and Yomisan Northwest (Zn-Mo) and Yomisan Southeast (Zn-Cu-Co), hosted in Ordovician carbonates in proximity to Cretaceous quartz porphyry intrusives. The Taebaeksan district hosts the largest deposits at the Yeonwha group of mines. Although production ceased in 1993, significant resources remain, hosted in Ordovician limestone and dolomite that have been intruded by Cretaceous quartz porphyry dykes. Deposits in the Cretaceous Gyeongsang Basin consist of bedding concordant, vertically stacked base metal skarn mineralisation at several stratigraphic horizons, connected by carbonate-base metal veins with a pipe-like geometry. Evidence such as massive sulphide layers and restricted proximal carbonates suggest mineralisation was initially partly syn-depositional, with both base metals and carbonate venting onto a lake floor, being reconstituted to skarns by later magmatic activity. Skarn mineralisation is universally closely associated with the Cretaceous Bulgugsa Series acid intrusive activity. A common intrusive-structural relationship is recognised at some deposits, with bedding plane and imbricate thrust faulting, introducing felsic intrusives as sills. These intrusions probably introduced the base metals, carbonate, boron, heat and silica, which metasomatically reconstituted the carbonate lithologies to form skarn assemblages. The Korean base metal skarn deposits are regarded as Zn-Pb chimney-manto skarns and display similarities to the Mexican manto type deposits.

Jan 1, 1999

It is indeed a privilege and honour to deliver the keynote address at this 15th APCOM symposium. APCOM has played a significant role in my own career and I am sure in the careers of many of the thousands of other participants over the years since its inception as a short course on "Computers and Computer Applications in the Mineral Industry" at the University of Arizona in 1961. The technical papers and addresses presented at the 14 past symposia provide an imposing record of sustained pro- gress and achievement in the field of computer applications. I will not attempt to analyse this technical side of APCOM but rather endeavour to provide you with a broad popular perspective of the road travelled to date and that lying ahead of us. The name of the series of symposia has changed from time to time, with titles such as Mathematical and Statistical Techniques, Mining and Exploration, and Decision Making being used at various times until in 1972 the name APCOM was coined and the present loga designed by the South African organising committee for the 10th symposium. It can conveniently be accepted as standing for:

Jan 1, 1977

Most new engineers in the mining industry do not realise the importance of legal obligations. During investigations the first question you are asked is: Do you have any proof or evidence? The smallest detail in an underground notebook or a diary entry is able to be used as your proof and/or evidence. The importance of a paper trail is often undervalued and overlooked when you first enter the industry. As a new engineer, all too often your legal obligations, including your duty of care are not given enough consideration. Whose job is it to inform you of what your legal obligations are and when do they end? Everyone has legal obligations at every level of the industry, from graduate to mine manager. The level of these responsibilities varies depending on the position that you hold. When you first start in the industry you need to understand what your responsibilities are and how you are expected to discharge them, whether they are memos, databases or senior sign-offs, etc. In order to fulfil your obligations you must first discharge your own obligation, which in turn discharges those of your department and ultimately those of the mine. As a graduate engineer in the mining industry what I have learnt about my own legal obligations has come directly from my own experience, which will form the basis of this paper.

Jan 1, 2007

Miners and mineral explorers are concerned at the increasingly hostile environment being generated towards their industry and their profession. There is little official or public recognition that the mining industry is essential for the maintenance of the country's standard of living; a large part of this hostile feeling is caused by the assumption that mining destroys large tracts of our attractive countryside. This paper presents a historic review of the impact on the countryside of the major land using groups commencing with the Polynesian migration. European farming practices, subsequent expansion of the urban dweller and the land management practices of the two Government Departments, Lands and Survey and New Zealand Forest Service who between them control half of the total land area, are discussed. Estimates of total land area to date, directly and indirectly affected by mining have been calculated and a broad estimate of 18 000 ha or 1/1500 of total land area is indicated; current annual mineral production requires some 240 ha. These gross areas take no account of subsequent land rehabilitation, its improvement upon the original in some cases and the recreational, historic and aesthetic areas gained. Comparisons are then drawn with some current land practices in New Zealand.

Jan 1, 1977

By R Price, B H. Miller

"The rise of autonomous haul truck fleets may have been initially driven by the rapid escalation of the cost of equipment operators, but the actual improvements reported by the major iron ore miners far exceeds the simple reduction in workforce. Utilising cost models developed for feasibility studies and mining contract modelling, the limits of cost improvements due to simple labour reductions are compared to those achieved by the early autonomous fleet adopters and through traditional process improvement techniques such as fleet class upgrades or hot-seating of equipment. As autonomous fleet implementation matures, it is likely that the gains seen by current adopters will seem minor compared to the limits generally governed by the limit of equipment utilisation. This ultimate limit is explored through time utilisation models, which were also developed for use in feasibility studies and mining contract modelling.Citation:Miller, B H and Price, R, 2016. Autonomous Haul System Savings - It's Not about Less Truckies but Better Truckies!, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 2–10 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

The character of alluvial gold deposits presents severe difficulties, and sometimes limitations, on the extent to which metallurgical efficiency can be measured. Very little monitoring of metallurgical performance is practised. An indication of performance is often extracted from the comparison of production to the estimate. This is a dubious practice. The recovery efficiency of conventional practices, viz sluices, tables and jigs, falls off sharply below 0.2 mm. Field evaluation procedures tend to simulate these conventional practices. Thus the presence of fine gold may not be detected, particularly if obscured by clay. There is increasing evidence that fine gold could, in places, be present in sufficient concentrations to be economic. Most gold in paleoplacers is finer than 0.1 mm. There are established practices elsewhere in the mineral industry that may physically recover gold down to 5 microns in size and which could find application for fine alluvial gold.

Jan 1, 1984