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The Porgera gold mine has made significant progress with the successful installation of a JK FrothCam image analysis system. The system is used to measure and control froth velocity on the scavenger circuit which has brought significant economical and operational benefits. The froth velocity signal, determined by analysis of the camera, is transmitted to the PLC that manipulates flotation cell airflow rate and cell level controllers to maintain a target froth velocity of 130 mm per second. Following on from a three-week trial installation in June 2000, a permanent installation was commissioned on the scavenger Outokumpu (OK150) tank cells. Further work is in progress on the rougher Wemco cells. This paper describes the evaluation of FrothCam Technology and its subsequent installation.

Jan 1, 2003

By R Nicholson, N D. Cox, N W. A Lambert

"This paper reports on the long-term operation of a particle density meter (PDM) at the Bloomfield coal handling and preparation plant (CHPP). This unit has been operating continuously for over three years, providing real-time data to the operators to allow the monitoring of flotation circuit performance. PDM outputs include slurry density, solids concentration on both mass and volumetric basis, and particle density. Knowing the average particle density of a stream allows for the optimisation of the process in real-time.The calibration of the solids concentration measurement device proved very difficult as the factory calibration techniques and existing laboratory analysis did not give accurate or reliable results. The solids concentration device had to be re-engineered and a new calibration method developed that gave accurate and repeatable results. Independent verification of samples taken from the PDM was undertaken as part of the trial process.The operational reliability of the PDM was a major point of investigation. The initial installation of the unit revealed issues with large, misplaced material of up to 20 mm periodically entering the unit, leading to feed blockages. The presence of these misplaced, oversized particles in the flotation circuit was resolved by installing innovative automatic back flush systems on the PDM.From a plant perspective the PDM has been an invaluable instrument that has enabled irregularities in the flotation circuit performance to be identified, which sampling had not and could not readily identify. This was achieved by close monitoring of real-time tailings composition on a minute by minute basis over short and extended periods. Variations in the tailings stream with respect to particle density and solids concentration were traced back to other issues in the plant. In addition, the PDM has allowed cell optimisation with respect to reagent dose rate to be improved. The PDM with real-time feedback can negate the need for large sampling campaigns and analysis during plant optimisation programs.Citation:Lambert, N, Cox, N and Nicholson, R, 2016. Particle Density Meter, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 245–250 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By P Commander

Western Australia is a major exporter of minerals, which places significant economic and environmental responsibility on Government and the stateÆs mining industry. Moving into the 21st century, mineral production in Western Australia is $14 billion accounting for 50 per cent of the stateÆs export income. There are over 60 large-scale mining operations distributed throughout the arid regions of the state (less than 300 mm/year rainfall). There are four key mineral provinces in arid Western Australia including the Pilbara (iron ore), Murchison (gold), Northern and Southern Goldfields (gold and nickel). These provinces have significant differences, particularly in respect to groundwater demand from mining and mineral processing, aquifer systems that are utilised, and approaches to groundwater management. The arid nature of the stateÆs interior and subsequent lack of surface water resources has required substantial groundwater resource development by the mining industry. A variety of aquifers have been explored and utilised ranging from shallow alluvium and calcrete, discrete fractured zones in bedrock, concealed palaeochannels and inland sedimentary basins. Groundwater usage by the mining industry is about 150 GL/year with most abstraction related to mine dewatering, mineral processing and dust suppression. Groundwater abstraction in Western Australia is regulated by the Water and Rivers Commission. In the Goldfields, the depletion of brackish (>2000 mg/L) and saline groundwater from storage is permissible, as mining is considered the beneficial use for groundwater which may be as much as 200 000 mg/L. In contrast, the low salinity groundwater of the Murchison and Pilbara is allocated on a sustainable basis. The role of monitoring and ongoing aquifer reassessment is crucial in water management, in evaluating the condition and performance of stressed aquifer systems. Mining operations face a variety of water resource issues ranging from insufficient availability for processing to excessive mine dewatering. These issues also change as a mine operation proceeds through its development, commonly starting with a deficiency and moving into surplus as deeper pits require more dewatering. Operating mines have to contend with three main issues: water supply, wastewater disposal and contamination of local water resources. In contrast, post closure issues are related to aquifer recovery or re-establishment of groundwater equilibrium, development of pit lakes in mine voids and isolation of waste products and associated seepage or run-off.

Jan 1, 2003

By M Ziemski

The provision and management of energy in both fuel and electricity forms is an increasingly important consideration for mines. Pressures from communities, governments and markets are increasing towards more transparent and improved energy management. Combined with the energy-water nexus, where water and energy are closely related in the operation of a mine, this emerging business climate means a more thorough and responsible approach is required for the acquisition and use of energy, as well as the release of emissions. Many of the complexities in potential new ore bodies are borne in remote locations, high altitudes, low grades, arid climates and deep deposits. Each of these challenges affects the successful provision of energy. In combination, such challenges can leave an operation seemingly unviable from an energy perspective, especially when approached from a traditional mining energy feasibility lens. This paper discusses some of the energy alternatives currently available and emerging in the mining industry. Both energy supply and demand options are considered, which can provide a very different energy footprint with the flexibility to address, and potentially overcome, major energy challenges for a mine. CITATION: Ziemski, M, 2018. Energy complexities in complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 106–111 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

The selection and implementation of the right technology for a project is critical to the future development of the resource industry. It is essential for companies to ensure ongoing competitive viability that where practical new or alternative technology be adopted. Analysis of historical data relating to development of resource-based process plants provides an enlightening insight into the key factors which influence their success or failure. The adoption of new technology does not guarantee the success of a project. The outcomes of this analysis have been used to develop some general guidelines and principles the author believes are useful in the selection and implementation of new or alternative technology in resource projects. This paper is available as a PowerPoint presentation only.

Jan 1, 2006

By A Jewbali, L Allen

At Newmont Corporation drill hole spacing studies are done to support the business in understanding the cost of collecting additional information (with a specific focus on drill hole sampling density) versus the value of additional drilling in terms of resource risk reduction. For the last 20 years drill hole spacing studies have been executed in an effort to answer the following question: What spacing should the deposit be drilled at to achieve a certain level of resource confidence so that when mining occurs the resource model delivers as predicted ie what is the optimal sampling density? The optimal sampling density supports a resource model that provides a sound foundation for mine planning purposes and resource/reserve reporting. At Newmont Corporation drill hole spacing studies are now a requisite for understanding drill data density needs for new deposits and near mine expansions. This paper details the evolution of drill hole spacing studies at Newmont Corporation in terms of methodology and usage.

May 24, 2023

By S Szylkarski, D N. Graham

In mining, water management is an operational necessity, requiring planning and detailed engineering, as well as risk assessment. Yet, the hydrology of streams and aquifers typically extends well beyond the boundaries of mine operations and intersect with environmental and social values. Mine managers often plan, design and assess the impact of water management activities (such as dewatering, excess water disposal and flood management) with a mine site or process specific focus. The challenge is that the impacts are spatial, long-term and complex – and may be cumulative across multiple mine sites. Further, there is usually little consideration of the feedbacks and interactions between surface water, groundwater and catchment hydrology. Failure to understand these processes can lead to poor decisions and increased costs. This presentation outlines an approach to simulating integrated hydrology in mining catchments that addresses the shortcomings of traditional modelling techniques.CITATION:Graham, D N and Szylkarski, S, 2016. Simulating integrated hydrology in mining catchments from planning to closure, in Proceedings Life-of-Mine 2016 Conference, pp 101–105 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By J Masliyah, Z Xu

The largest oil sand deposit in the world is located in Alberta, Canada, with a total proven reserve of 2.5 trillion barrels of oil. The water based extraction process is currently being used in commercial operations to recover bitumen by flotation from oil sand ores. A recognised challenge in bitumen extraction is the reduced bitumen recovery when processing ores containing high fines content or æweatheredÆ oil sand ores, collectively known as poor processing ores. Inspired by demonstrated success of using kerosene as collectors in coal flotation, an innovative idea of using oily bubbles (air bubbles coated with a thin layer of oil or solvent) was tested to improve bitumen flotation recovery from poor processing ores. In this study, dynamic contact angle of air bubbles or oily bubbles on bitumen and induction time of bitumen-oily bubble attachment in water were measured to justify the use of oily bubbles in bitumen recovery from poor processing ores. The type of oil or solvents, including kerosene, toluene and naphtha, used in generating oily bubbles showed a marginal effect on the contact angle values, similar to the values measured with air bubbles. However, the spreading of an air bubble was found to be much slower than that of oily bubbles on a bitumen surface. The induction time for oily bubble-bitumen attachment was found to be much shorter than that for corresponding air bubble-bitumen attachment in the process water from poor processing ores. The reduced induction time for kerosene-coated air bubble-bitumen attachment correlates well with the improved bitumen recovery from poor processing ores using kerosene-coated oily bubble flotation technology.

Jan 1, 2005

By W Dodson

Major ions, d18O and d2H and Carbon-13 concentrations in groundwater from 30 bores near an open pit iron ore mine were used to better understand the chemical evolution of groundwater in the aquifer. The relatively depleted d18O and d2H isotopes of groundwater from various depths suggest that groundwater is recharged from intense rainfall events, with little evaporative effect. The 300 to 500 mg/L increase of major ions relative to that of rainfall is due to evapotranspiration of rainfall during recharge. Geochemical mass balance modelling suggests that the evapotranspiration of rainfall during infiltration through the unsaturated zone varies over six fold from 20 to 130. This coupled with the dissolution of CO2 from the unsaturated zone and partial dissolution of carbonates and gypsum from Tertiary sediments and carbonates from the Wittenoom Formation accounts for the current major ion, d18O and d2H distribution in groundwater. Despite the relatively dissected morphology and steep hydraulic gradient the results of this study highlight the dominance of vertical flow relative to horizontal flow. The study also shows the dominance of rapid recharge by significant rainfall events as an important component of the water budget for east Pilbara aquifers.

Jan 1, 2009

By N Anderson

With traditional grade control processes, geological models are created by geologists at the completion of the data collection stage and wireframe construction is closed off at a set date to allow for time to complete the estimation process. Any issues identified at earlier stages or the addition of new data requires the estimation process to be started again. Alternative interpretations are explored only if time allows and often in a limited fashion. An alternative workflow has been developed at the Waihi Underground Gold Mine utilising Leapfrog Edge and Seequent Central. Geological and grade control models are created, dynamically linked, and saved as separate branches. A project geologist is able to work on the grade control model and a mine geologist on the geological model simultaneously. This allows for a non-linear modelling workflow with continual review and feedback. The introduction of new data can occur right up to the model due date, with data collection, validation, alternate interpretation, and review happening incrementally. Models are categorised and stored in Seequent Central according to project status. An approved version of the geological model and grade control estimate are uploaded at the time of release and transparently capture all data used at a point in time, as well as the review process. Dynamically updating models for grade control has reduced turnaround time while increasing accuracy and quality. Estimates of individual domains are vastly improved from being able to rapidly evaluate the effects of model parameter changes in real time and 3D. Development and stope design directly benefit from these streamlined processes, with higher quality, timely production occurring as a result.

Mar 22, 2022

By P Oikkonen

Sprayed concrete has played an integral role in underground rock support for nearly a century. However, concrete is also considered to be one of the biggest environmental problems in construction and mining, largely because of the high carbon footprint of cement and aggregates production. This is driving the industry to find ways to cut concrete usage where possible. Improving sustainability by cutting concrete material consumption also reduces application time and costs. Improving concrete properties can make it possible to design thinner linings, but as awareness of safety and longer design lifetimes are driving developments in the opposite direction, it is not realistic to see this as a major factor in cutting concrete consumption. More accessible solutions are focusing on layer thickness control and minimising rebound and wastage. Digital technology and innovation offer excellent tools for improving sustainability while optimising other aspects of the spraying process at the same time. A digital layer thickness control system gives near-real-time information to the sprayer operator with full coverage of the sprayed surface. This enables the operator to achieve consistent layer thickness on the first pass, in comparison to the traditional methods of overspraying with the aim of achieving sufficient layer thickness, probe drilling after the concrete has set, and respraying at a later stage if needed. Operator competence is the single biggest variable in a successful sprayed concrete process, affecting rebound and wastage levels. Unfortunately, the learning curve to become a master sprayer is quite steep and training on a real sprayer and real concrete requires a significant amount of time and money. Training in a virtual reality (VR) environment enables operator training to be carried out in a low-risk environment and provides a way of measuring performance and assessing and certifying the operators. After the VR training period, a novice nozzle operator has the basic understanding to start working on a real sprayer, and an experienced nozzle operator can benefit from the possibility of assessing their performance.

Mar 29, 2023

By R Jacobs, J Yeates

"The Stockman base metals project is situated in State Forest in the alpine area of East Gippsland, Victoria, adjacent to a National Park and within the headwaters of a major Ramsar-listed wetland catchment and the Murray-Darling River system. Site topography is steep, and elevated (650 m – 1200 m above sea level), and subject to circa 1 m annual rainfall, with occasional winter snowfall. The project consists of two volcanogenic massive sulfide (VMS) deposits to be mined by underground methods and treated in a 1.0 Mt/a central concentrator to produce copper and zinc concentrates for export over a ten year operational life. New resource projects are rare in Victoria. Recognising the sensitive setting, planning for the Stockman Project, which is now in the advanced permitting stage, has focused on balancing economic, environmental and social outcomes to ensure social licence to operate is secured and can be maintained. This has involved close attention to triple bottom line (TBL) risks and outcomes. Stockman has successfully gained State and Federal approvals via the Environmental Effects Statement process. The process of obtaining these approvals has required close attention to effective stakeholder involvement, and management of a lengthy and difficult approvals process, which is still to be finally concluded. This paper is a case study of the process of that permitting and the issues encountered to date. Key learnings from the experience have included: successful approvals require close attention to much more than just the project and its technical aspects and physical setting – effective stakeholder involvement and endorsement is critical the differing consultation requirements for local, regional and government stakeholders, to design and plan implementation of a project to meet TBL objectives, and to gain social licence to operate within the Victorian approvals process, the need for an effective lead government agency with policy authority dealing with material policy change requiring post-closure financial sureties estimating realistic permitting time and cost during the project evaluation phase. CITATION: Jacobs, R and Yeates, J, 2016. Stockman base metals project – sustainability, social licence to operate and permitting lessons learnt, in Proceedings Project Evaluation 2016, pp 98–110 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By P Hatherly, A Melkumyan, D Wyman

Chemical species distributions in rock sequences can be modelled using Gaussian processes (GPs) to predict the weight percentage between known data points. This method can be improved by dividing the modelled area into regions of different mineralogy. In the context of many iron ore deposits, marker shales give the initial guidance of where these regions may lie. These shales give rise to distinctive peaks in the natural gamma downhole logs, which are conventionally identified by hand. A GP method has been developed to automate this task.Once the appropriate boundary has been located on the basis of shale occurrences, chemical assays from exploration drill holes are used to find the exact boundaries of interest. These boundaries divide the drill hole stratigraphy into regions of different mineralogy, each of which display their own distinct correlations between the main elements and oxides (Fe, SiO2 and Al2O3). Iron ore shows a negative correlation between Fe and Al2O3, but in banded iron formation (BIF) there is a positive correlation between these species. Similarly, SiO2 and Al2O3 have a positive correlation in the shales and ore but a negative correlation in the BIF. Correlations obtained within ore-, BIF- and shale-dominated regions are therefore better than those obtained using the entire log and can be used to improve the results obtained when modelling.

Sep 26, 2011

By L Neems

In conjunction with Orica Explosives, Worsley Alumina have managed a program of continuous improvement to their cap rock blasting over the last two years. Blasting conditions are challenging because of the hard and shallow nature of the material. Blasting costs must be controlled and the environmental consideration of noise and dust is critical. Worsley have sought to determine the optimum balance between drilling and blasting costs and fragmentation. As the cap rock has few inherent weaknesses, loader productivity is strongly controlled by the degree of fragmentation from blasting. The optimum blasting solution is also constrained by maintaining airblast levels at the surrounding residences below 115 dBL . The major blast design parameters optimised during the program were stemming type, stemming length, powder factor and blasthole diameter. A series of carefully managed trial blasts were fired during 1997 and 1998 to quantify the effect of these parameters. Fragmentation was digitally measured using OricaÆs Powerseive G technique. Shovel productivity, airblast levels and blasting costs were also quantified. As a result of the project, Worsley now have an increased knowledge of the key parameters driving blast performance, and their consequent impact on downstream processes, the environment and total mining cost.

Jan 1, 1999

By G Simpson, S Dressler, A E. Levett

Tailings storage facilities often represent a mining operation’s most significant liability, posing serious environmental, social and safety risks. Almost all mining operations dispose of wet tailings (Valenta et al, 2023), which represents a risk of failure due to the potential for a rapid strength reduction of the unconsolidated materials leading to static liquefaction and subsequent dam wall failure. As a waste stream, tailings disposal, decommissioning and relinquishment aim to be inexpensive processes, ruling out many highly engineered solutions. Advantageously, tailings consolidation does not need to be immediate, opening the door for relatively passive, inexpensive consolidation methods that aim to gradually increase the strength of tailings over extended periods (ie years). In this paper, we present the prospect of novel in situ tailings stabilisation, learning from studies that have investigated the most erosion-resistant landforms on Earth.

Aug 2, 2023

By M E. Karmis

Traditional coal mining planning seldom considers key æsustainability factorsÆ such as: societal impacts in the area; jobs (both created and lost); dislocation of towns and residences; impact on neighbouring communities and individuals; infrastructure concerns; post-mining land use (except when limited by law or other factors); habitat disruption and reconstruction; long-term economic impacts in the community; and net long-term community benefit. This paper presents a systems engineering approach based on the premise that systems can only be optimised if all factors are considered at one time. In theory, coal mine designs can be optimised for return on investment, environmental protection and sustainability. Using this approach, the permitting process may be quicker and less costly, relationships with neighbours, communities, environmental groups may be improved, the mining industry may be seen as a positive for the short-term and long-term and the mining industry may increase profits. This paper discusses geographic information system (GIS) tools that may be used to incorporate ecological and other sustainable development concerns into models of coal mine sustainability performance. Along with coal production cost and value information obtained from past and present coal mining operations, GIS data are used to develop mathematical cost and equation models. By analysis of on-the-ground data, the parameters to be included in these models are identified, the relationships between these parameters quantified and the models developed. The paper also discusses the next phases of the work to be completed once the data is obtained and the models are adjusted and validated. At that time, site-specific information will be input into the models and the approach to mining a particular property evaluated and optimised for financial rate-of-return and other desired outcomes, such as preservation or enhancement of sustainability values. Finally, the paper will examine how this approach can be combined with traditional mining engineering considerations in order to develop an optimised mine plan for a specific mining property.

Jan 1, 2009

By B Murphy

Safescape Laddertube provides an improved system for emergency egress in ventilation shafts. The addition of Laddertube in a rise has very little impact on ventilation flow, studies have indicated that the difference in flow velocities are difficult to measure due to the minimal impact. Due to the size and open-ended nature of Laddertube, the air velocity inside and out of the Laddertube is mostly linear. Laddertube can be used either permanently or during an emergency as a secondary ventilation duct. One project involved a 385 m ladder installed in a surface return air raise that could be made to bypass the primary circuit and supply fresh air to a sea container fresh air base at the bottom of the raise. Laddertube has been designed to be installed to any feasible length and can be fitted with a climb assist system ensuring enhanced speed and reduced fatigue during ascent. The climb assist used in association with Laddertube is a Tractelift system which applies a weight relief of up to 36 kg off the climber’s body weight when using the ladder. This system has successfully been tested for ladders up to 600 m in length and is currently in use for a ladder of 185 m length. The use of refuge chambers in underground coalmines has long been a contentious issue due to the concern that while it may provide temporary shelter, the risk of being exposed to high heat or the inability for rescuers to access them due to fire or explosive atmosphere means that they may be effectively trapped. The additional application for coal environments includes Laddertube installed alongside a refuge chamber concealed behind a blast proof door ensuring a secondary means of emergency egress. In certain operations designs may allow for this chamber to be provided withpositive pressure fresh air.

Oct 12, 2022

By Toussaint LF

A brief history of the mineral sands industry is given from a radiation protection standpoint, with gamma radiation and inhalation of radioactive dust being identified as the main sources of radiation exposure of persons working in the plants. The principal sources of gamma radiation exposure are identified and the history of early bagging methods is discussed. The concept of ALARA is introduced and the impact of the "bulka bags" (and more effective monazite storage facilities) are detailed as illustrative examples of dose minimization, together with the requirements for the transport of monazite. The dose from radiation received from inhaled dust is dependent on a number of parameters of the dust, some of which are not well known. ICRP 30 (1978) makes recommendations relating to the intake of radionuclides by workers. These recommendations are discussed with respect to the inhalation of dust containing thorium. The possible pathways of radioactive material throughout the body are also described. The effect of having parameters that differ from ICRP 30 is discussed and suggestions are made relating to measurements that can be carried out to more accurately determine these parameters. Since in some instances the exposures to dust yield personal doses which may exceed the annual ICRP 30 based limits, it is necessary to define more accurately parameters of the dust so as to determine more accurately personal Doses.

Jan 1, 1986

By S Tierney, D Cumming-Potvin, I Thin, Y Potvin, D Grant

The preliminary modifying factors for future stope design in the Southern Mine Area of Olympic Dam consisted of only a single, arbitrary value of Equivalent Linear Overbreak/Sloughing (ELOS). In order to improve this, a study was conducted which developed a more comprehensive methodology for assigning ELOS, Equivalent Linear Lost Ore (ELLO) and Equivalent Linear Fill Overbreak (ELFO) to individual stope faces based on geotechnical and mining parameters. The approach used was to look at the simple cases, which were classed as vertical stope walls in good ground (RQD 80-100%), divided into wall orientations (North, South, East, West). The stope walls were also split based on the blasting practice used (toeing, parallel or a combination of the two). The expected ELOS and ELLO from these ‘base cases’ are then modified by parameters which have historically been found to affect stope performance (Hydraulic Radius and Q’). The size of the effect found in the historical data determines the ELOS / ELLO applied. The methodology was summarised in an easy to use flow chart and was applied to all of the proposed stope shapes for the Southern Mine Area and summarised per mining block. This allowed each iteration of the mine plan to be assessed in terms of overbreak (both rock and vertical fill exposures) and underbreak.

Mar 15, 2021

By A G. L Pratt

Inclined troughed belt conveyors are more frequently being selected from a range of alternatives, which include shafts and trucks for ore haulage in underground mass mining projects. Belt conveyor haulage systems are being operated with lifts exceeding those normally associated with truck haulage systems and approaching the limits of shaft haulage systems. A belt conveyor haulage system, in this context, incorporates subsystems for: crushing,tramp detection and removal, andhaulage. This paper presents details of recent inclined troughed belt conveyor systems for underground mining operations, and explores the application of inclined troughed belt conveyors for the increasing demands of future underground mass mining projects.

Jan 1, 2008