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By S Larbi-Bram, F Shi, E Manlapig

Mining companies have recognised that characterisation of particle breakage plays an essential role in the design and optimisation of comminution circuits. Recently the JKMRC comminution research team has developed a new breakage model incorporating the effect of particle size, and a new breakage characterisation testing device, called the JK Rotary Breakage Tester (JKRBT), which allows rapid testing of particle breakage under high energy single impact and low energy repetitive impact conditions. The latter is believed to be the dominant breakage mechanism in AG/SAG mills. Existing devices, such as the JKMRC Drop Weight Tester, are not suitable for performing repetitive impacts since they are too time consuming. Positive feedback received from mining company sponsors to the new technology has prompted the JKMRC to further validate the device and the model through a formalised experimental test program on professionally designed and manufactured JKRBT machines. The first JKRBT was installed at the Anglo Research laboratory in Johannesburg in March 2007 and four more major mining companies will participate in the project in 2008, with commercial release expected in early 2009. The JKRBT has the potential to revolutionise ore testing, with applications in laboratory impact breakage characterisation of rock samples, drill cores, coal and other materials. It also stands poised to significantly advance the process control of comminution circuits since it is readily adaptable to on-line ore hardness measurement. Can any mine afford to miss out on this technology?

Jan 1, 2008

The seminar had its origins in an Inquiry into the Box Flat Disaster and one of the conclusions from this Inquiry was that there should be a better dissemination of technical knowledge and the results of research work. As a result of this Mr. W. Roach, Chief Inspector of Coal Mines in Queensland and Mr. R. Menzies, Chief Inspector of Coal Mines in N.S.W. had a meeting to see how this could be done. They concluded that it would be difficult to have the sort of regular meetings that would be possible where distance was not significant, but a seminar would be a major step toward satisfying this particular conclusion of this Inquiry. As a consequence, Mr. Roach, who is on the Committee of the Southern Queensland Branch of the Institute, suggested when the Branch programme was being planned this year that a meeting of this type should be held, and the Mine Fires Seminar which was held today is the result. We have received a great deal of support in arranging the Seminar. First and foremost I wish to acknowledge support from the National Coal Board in United Kingdom. Not only have they released Dr. Willett for a period of six to seven weeks to visit Australia, conduct the Seminar and give a series of lectures in various areas through the country, they have also borne the brunt of the financial support that has been necessary to make this possible. In addition we have received considerable support from many organisations in Australia. I 'mentioned this

Jan 1, 1973

By N Winkelmann

Underground coal heating is a significant hazard in some coal mines. The broad principles of how underground coal heatings occur is reasonably known, however the technique for locating the heatings in often inaccessible goaf has been proved to be difficult. Since 2002, CSIRO, with the support of the Australian Coal Association Research Program (ACARP) has been undertaking investigations to apply and develop innovative surface-based radon technique for locating the underground heatings in Australia. This paper presents the progress of the investigation.

Jan 1, 2005

Hoisting ropes are constructed of wires and strands positioned helically around the axis. This helical positioning causes that, in the rope loaded at the end with the weight Q, the longitudinal displacement u, axial force P, torsional displacement v and constant torsional moment M are generated. More over, the proper weight of the rope q gives the force acting along the axis of the rope. This force changes its value from 0 at the bottom to qL at the top. This force gives, along its length, a variable torsional moment making the rope rotate. During the movement of the conveyance downwards the falling part of the rope rotates, which makes it untwist on the section up to the half-depth of the shaft and twist on the other half-depth. As the result, the twisting lay of the rope changes increasing in the upward direction and decreasing downwards. The angle of twist of the strands changes in an apposite way. When moving upwards, the uplifted rope does not twist and retains its state of deformation up to the moment when it passes over the pulley. Next, the cycle of untwisting and twisting repeats during the movement of the other conveyance downwards. This phenomenon is known from mining practice. It was also analysed, in the works of Glushko (1966) and Popowicz (1963).

Jan 1, 1995

By Kewu W

Kaolin used as an industrial mineral, especially that in the paper-manufacturing industry, must be of fine size, with high brightness, a low impurity content, and good crystal shape. However, in most kaolin deposits there are various impurities which have a very bad effect on the quality of the kaolin. Therefore, it is necessary to remove these impurities from kaolin ore. Owing to their similar surface properties, the separation of kaolin and iron oxide minerals, especially microkaolin and iron oxide minerals, has been regarded as difficult. The iron oxide minerals often intergrow with kaolin in fine and complicated forms, such as thin films, which make separation difficult. In order to overcome this difficulty, many workers have suggested various treatment methods and obtained great success. Based on research work by Fuerstenau (1980), Huang, Li and Hu (1984), Hui and Wei (1991), Shergold (1978), and Zambrana et al (1974), we have investigated a two-liquid flotation technique for iron removal from kaolin and obtained some success.

Jan 1, 1993

By C Beal

Proper understanding and management of production drilling in sublevel cave (SLC) mines is essential for meeting production targets and for avoiding inefficiencies that could lead to costly bottlenecks. In many SLC mine management models drilling is considered a derivative activity of firing and bogging. Its scheduling is considered to be implied in a firing schedule and given an arbitrary target completion, ‘several weeks’ or ‘a month’, ahead of production firing. Like development, drilling activities are most efficient when conducted separately from other production activities. Unlike development, however, it is not apparent during planning and feasibility how far in advance of firing drilling activities ought to be conducted. This paper presents a method of defining a minimum threshold of drilled stocks above which drilling, firing and bogging operations occur most efficiently. As an example, the drilling activities, procedures, and maintenance at Glencore Xstrata’s Ernest Henry Mine are presented, and the larger scale consequences of improvements to these areas are presented to illustrate their importance in the operation of an SLC mine.CITATION:Beal, C, 2014. Understanding the role of production drilling and drilled stocks in efficient operation of a sublevel cave mine, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 235–242 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By G Chitombo, A Perryman, A D. Campbell, J White, B Hollis

This paper describes the development and implementation of an optimisation tool developed as part of the Mass Mining Technology (MMT) Project. The tool, known as the SLC Schedule Optimiser, is capable of optimising the schedule of development and production activity for a sublevel cave, given a fixed draw strategy, for the life of the mine.This paper starts by describing the development and production scheduling problem for a sublevel cave, the geotechnical constraint that a schedule of activities must adhere to, and outlines the pre-existing manual planning procedures used to produce schedules.Following this, the paper then outlines the optimisation tool developed, describes the changes to the planning process it has enabled and finally quantifies the improvement to operations this tool has brought using Glencore’s Ernest Henry Mining Operations as a case study.CITATION:White, J, Perryman, A, Campbell, A D, Hollis, B and Chitombo, G, 2016. Life-of-mine development and production scheduling optimisation for sublevel cave operations, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 133–138 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By T Huynh, V Matanitobua, J Zheng, B N. Noller, J C. Ng, H H. Harris

A risk assessment was undertaken of the aquatic ecosystem and bioaccumulation of metals and metalloids in fish at the Leichhardt River, Mount Isa, Queensland. Residual contamination of metals and metalloids in Leichhardt River sediment was assessed and arose from mine practices using river discharge in the 1940s. The ecological risk assessment of sediments involved comparison of the concentrations of heavy metals and arsenic with those of the ANZECC/ARMCANZ (2000) Interim Sediment Quality Guidelines (ISQG). Results indicated that all sites including the background site exceeded one or both the ISQG-high and ISQG-low trigger values based on total concentrations. A lesser number of sites exceeded the ISQG-low trigger values following the 1 M hydrochloric acid extract step, which was used as an indication of bioavailability. An additional risk from particulate matter in river sediment is that acute human toxicity from the consumption of fish contaminated with metals and metalloids is unlikely. The potential risk was assessed by comparing with the maximum levels set by FSANZ (2010) for fish consumption by children and adults. In general, the liver of the fish have higher heavy metal and metalloid concentrations compared to the muscle. Frequent or regular consumption of fish from the Leichhardt River that exceed maximum levels (ML) of heavy metals and metalloids is not recommended. Risk analysis showed that an adult can consume up to 5 kg of fish fillets every day from fish caught at the man-made Lake Moondarra downstream on Leichhardt River and still be within safe consumption levels whilst a child can eat up to 1 kg daily.CITATION:Noller, B N, Ng, J C, Matanitobua, V, Harris, H H, Zheng, J and Huynh, T, ?2014. Assessment of ecotoxicology and health risk from bioaccumulation in fish of heavy metals and metalloids from historical mine practices in the Leichhardt River, Queensland, Australia, in Proceedings Life-of-Mine 2014 , pp 337–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By R J. Higgins, M Edraki

What is the meaning of the Life of a Mine (LOM) if that mine results in a requirement for water treatment in perpetuity? ‘In perpetuity’ is of course a duration with no relationship to a Life-of-Mine or what might rightly be regarded by external stakeholders as a fair and reasonable post-mine recovery period. It exceeds the life span of investors, mine managers and governments, indeed even of capital markets as we know them, and of corporate and individual memories.In mine and mine closure planning, decisions are usually based at least to a significant extent on traditional economic analysis underlain by discounted cash flows (DCF). For investments in income-producing facilities, such as mining development and equipment, and ore-processing plant and equipment, this analysis reflects commercial reality and allows for comparison of competing investments. However, for environmental and social infrastructure, the same analysis using the same input parameters, especially the discount rate applied to cash flows, can lead to a bias against the adoption of best practices for non-investor stakeholders. CITATION:Higgins, R J and Edraki, M, 2018. Water treatment in perpetuity – or not?, in Proceedings Life-of-Mine 2018, pp 131–132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By H Askari-Nasab, E Torkamani, M M. Badiozamani, S P. Upadhyay, M Tabesh

"Decision-making in mining is a challenging task. Optimal decisions regarding shovel and truck allocations, aligned with the optimal short-term production schedules, are crucial in keeping the operations in line with the company’s long-term objectives. In this paper, we present two main modelling components as the means to achieve near-optimal operational plans: a mixed integer linear goal programming model to allocate trucks and shovels to mining faces over a shift-by-shift basis so that operating costs are minimised and resource utilisations are maximised through the planning horizon a discrete-event simulation model to investigate the behaviour of a truck-and-shovel haulage system in the presence of uncertainty within mining operations. The goals integrated into the mathematical model are to: maximise production minimise deviations from the target head grade minimise deviations in tonnage feed to the processing plants from the desired feed minimise operating cost.The mathematical model provides shovel assignments and the target productions as an input to the discrete event simulation model while meeting the desired goals and constraints of the mining operation. We illustrate the applications of the discrete event simulation model by presenting a large-scale oil sands case study. The main contribution of this work thus far is the development, implementation and verification of a simulation model with a link to optimal short-term mine schedule and extraction sequence of mining faces, which assists in achieving a high level of mine plan compliance across short-term planning and operational planning time horizons.CITATION:Askari-Nasab, H, Upadhyay, S P, Torkamani, E, Tabesh, M and Badiozamani, M M, 2014. Simulation optimisation of mine operational plans, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 299–312 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By H S. Mitri, A Sainoki

Destress blasting techniques have been widely employed in underground mines for the purpose of preconditioning highly stressed rock mass. Appropriate applications of the technique successfully contribute to increasing mine safety (eg mitigating the risks for rock bursts). This paper presents a simulation technique to estimate the extent of damage zones induced by destress blasting. A 3D numerical model with a single blasthole is constructed with FLAC3D code, whereby static analysis is carried out in which horizontal and vertical stresses are applied to the model in order to simulate stress conditions in a deep underground mine. Afterwards, dynamic analysis is performed whilst applying time-varying blast pressure along the blasthole. The blast pressure profile takes into consideration an instantaneous increase and gradual decrease in blast pressure as well as the propagation of detonation along the blasthole. In this paper, constitutive models allowing for shear and tensile strengths of rock mass that are dependent upon strain rate are newly implemented into FLAC3D code with C++ programming language, whereby blast-induced damage is assessed by the extent of tensile and shear failure zones. The results obtained from the dynamic analysis show significant decrease in the extent of yielding zones induced by destress blasting with increasing the magnitude of in situ stress. They indicate that considering in situ stress state is indispensable in order to propose proper blast design for each level in underground mines. Based on these results, the relationship between the extent of the damage zone and depth at which destress blasting is performed is established. Furthermore, stress dissipation induced by destress blasting is examined with static analyses, in which the modulus of elasticity is decreased according to a rock fragmentation factor, a, only for the area where tensile and shear failures takes place during the dynamic analyses. A model parametrical study with respect to a is undertaken. The relationship between the rock fragmentation factor and the stress dissipation in the yielding zones is developed from the parametrical study. The developed relationship can be useful when destress blasting is designed for massive rock masses.CITATION:Sainoki, A and Mitri, H S, 2015. Simulation of damage zones induced by destress blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 245–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By H Parra, D Zenteno

Fragmentation modelling has been in use in the mining industry for a long time; however, there are still some aspects to tackle with regard to its use for strategic/planning and day-to-day purposes.On one hand, an important amount of resources are allocated to the task of calibrating and validating a good fragmentation model. Nonetheless, errors during the implementation stage introduce uncertainty into the prediction.On the other hand, it is common practice in the mining industry to use only discrete values to represent the fragmentation from blasting (k20, k50, k80), which provides a biased interpretation of the situation as, for instance, the best and worst possible cases are not taken into account. This is particularly critical when a continuous improvement philosophy has been adopted and modelling is used to either modify the drilling and blasting designs or plan ahead.It is well known that every site has particular conditions (rock mass, equipment, drilling and loading practices, among others) that often define unique trends in implementation. These trends can be captured using statistic and probabilistic techniques and then used as proxies for further analysis.This paper explores the potential of including implementation data in the form of probabilistic distributions into the Swebrec model to improve the performance of this engineering tool during the decision-making process.The fragmentation results of four designs were modelled using three different degrees of accuracy in the implementation for the burden, spacing and explosive column length.The data analysis showed that the probabilistic approach helps to achieve a broader perspective regarding the fragmentation that it is possible to obtain and the implications for the subsequent processes. The analysis also showed that the likelihood of producing similar fragmentation with different designs (involving different powder factors and costs associated) increases with the variability of the implementation.CITATION:Parra, H and Zenteno, D, 2015. Evaluating the inclusion of the implementation variability into fragmentation modelling, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 121–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J Palarski

Over the last 100 years in the Polish mining industry considerable work has been done to assess optimum slurry, develop flexible delivery systems and adjust the fill technology to a wide variety of mining and geological conditions. Sand or industrial mineral waste materials for the backfilling of underground voids are used to control ground movement and surface deformation. This paper discusses various criteria to he considered in the preparation of a fill, including slurry properties, mine infrastructure, mining geometry, placement methods and the purpose of the backfill. This paper presents laboratory and in situ test data on the influence of materials parameters on the slurry flow in a pipeline system, stiffness, permeability, binding time and strength of a backfill, on the distribution of mixture in underground voids or the penetration between roof fall Materials.

Jan 1, 1998

Mining is a necessary part of our modern lifestyle. However, mining can cause damage and pollution of the environment and therefore we must manage our resources wisely accounting for the physical, biological and social environments. Contrary to the view of some people not conversant with the facts mining has in many cases improved the environment. This paper described how two sand dune systems that were unstable prior to mining have been stabilised by revegetation after mining.

Jan 1, 1987

By Ovchinnikov YN, Novikov VS, Spirin NA, Babushkin NM, Mysik AF, Shcherbatskii VB, Kukarkin AS

Laboratory investigations were carried out to determine the resistance coefficient of the flow through beds irrigated with wetting and non-wetting liquids. A formula was obtained which may be used to evaluate the resistance of the irrigated packing. Quantitative investigations were also carried out on operating furnaces at Magnitogorsk. Continuous measurements of the lower pressure drops were made under different furnace conditions. Pressures were measured in the tuyere space and the bosh region. A significant transient behaviour of the pressure drop was observed in the irrigated zone as a function of the accumulation of the liquid phase in the bosh region as smelting progressed. Additionally, transient processes were also investigated in the upper furnace zones. The basic cause of the transient behaviour was shown to be the irregularity of burden descent caused by the casting cycle. It was shown that the rate of burden descent between consecutive casts reflects fairly accurately the accumulation and drainage of the liquid products as a result of which heat transfer, reduction and aerodynamic processes assume transient character. In practically all cases of casting a decrease in blast pressure and that over the furnace height of 0.2 kg/cm2 was observed. The analyses of radial gas composition at the stock line showed that compositional variations connected with the casting cycle are most pronounced in the central and peripheral regions, whilst in the intermediate regions the conditions are relatively stable. Calculations show that as casting progresses there is a decrease in the gas flow rate at the periphery and an increase in the centre of the furnace. The transient nature of the aerodynamic processes in packings revealed the existence of an appreciable reserve capacity. Elimination of transience was tested on the furnace at Magnitogorsk and improved operating and economical furnace parameters obtained.

Jan 1, 1975

By C Preston, T Williams, D Roy

The easiest way to mine valuable orebodies is through the use of explosives and well-planned blasting layouts that produce fragmentation profiles designed specifically for conveyance equipment in underground mines. The design of blasting patterns is specific to not only the explosives being used but also the rock or ore type being fragmented. Many blasting designs are based solely on the experience of those developed for similar orebodies in terms of properties and orientation or individuals that have some blasting experience.The primary technical objective of this paper is to outline a unique methodology for determining underground blasting methodologies (developing specific blasting parameters) commensurate with explosive energies and rock/ore equations of state for a narrow-vein gold property located in Northern Quebec and for underground mines in general.The procedures developed are to define the desired fragmentation specification so that a specific thermodynamic break is generated, taking into account powder factor, energy factor, tonnages, explosive energies and distribution along with blasthole diameter and orebody orientation for a specific set of explosive and dynamic rock/ore properties. Determining dynamic modulus values for the ore using seismic sensors to measure P- and S-wave velocities, the aforementioned parameters will be utilised to set the design constraints to maximise recovery and minimise overbreak and dilution.New underground blasting software (AEGIS) will use thermodynamic break in conjunction with defined fragmentation profiles to create an array of blasting parameters used to design and plan ring layouts. This software will also allow mining planners, prior to drilling and loading a production blast, to appraise future intended blasting patterns to minimise the potential of diluting ore with host rock and the likelihood of damaging mine support structures.CITATION:Roy, D, Williams, T and Preston, C, 2015. Underground stope drill and blast designs optimisation program, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 137–148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By N A. S Webster

The reaction sequences involved in the formation of iron ore sinter phases were determined using in situ synchrotron-based X-ray diffraction. Experiments were carried out using a synthetic sinter mixture containing 77.36 per cent Fe2O314.08 per cent CaO, 3.56 per cent Si.O2 and 5.00 per cent Al2O3 corresponding to a basicity of ~4. The alumina content represents the upper level of alumina concentrations measured in phases formed in industrially produced plant sinter. Data were collected during heating of the sample to 1350°C under an atmosphere of 0.5 per cent O2 in N2, equivalent to an oxygen partial pressure of 5 × 10-3 atm. This temperature was sufficientto ensure melting. Data were also collected on cooling of the sample back to room temperature to examine recrystallisation of phases from the melt.Results showed the sequence of reactions initially involved the formation of calcium ferrite phases C2F and CF. These subsequently reacted with the silica and haematite leading to the solid state formation of SFCA and SFCA-1. SFCA and SFCA-1 were the last phases to form in the system and were both stable up to ~1260°C. Above ~1260°C, melting of the SFCA phases and reduction of the remaining haematite occurred producing the assemblage magnetite + melt.During cooling, both SFCA phase types recrystallised from the melt initially coexisting with magnetite until secondary haematite formed. This is the fi rst study to demonstrate that both SFCA and SFCA-1 are precipitated from the melt during cooling of iron ore sinter. Future work will extend the range of compositions studied to examine the effect of basicity and alumina concentration on the phase assemblages as a function of temperature and oxygen partial pressure.

Jul 11, 2011

By CorrOa de Araujo A, Salum MJG

The treatment of mining and metallurgical liquid effluents is becoming, everyday, a necessity felt by these industries. Physical-chemical and chemical methods for treating such effluents are generally necessary whenever heavy-metals and other toxic compounds such as cyanide are present. The present paper discusses the use of precipitate flotation as an alternative physical- chemical method that can be applied for the treatment of effluents containing heavy-metals (mainly zinc and cadmium) and cyanide. Examples of laboratorial scale applications on real effluents are given. In both cases precipitate flotation was able to reduce the concentration of toxic components of the effluents at a very high removal rate, generating a solid waste that can either be disposed, re-used or recycled. A cationic collector - dodecylamine hydrochloride - demonstrated to be the best choice of surfactant for the two systems investigated. Sodium sulphide and dithizone were selected for the precipitation of the zinc bearing effluent whereas a copper salt was preferentially used for precipitating cyanide in a form adequate for its recycling envisaging the use of an AVR (acidification - volatilisation - regeneration) technique.

Jan 1, 1993

By D Duan

In this study, aimed at two kinds of ore (lump ore and iron ore fines) and four types of Australian iron ore resources (haematite iron ore, Mara Mamba iron ore, limonite iron ore, and mixed iron ore, such as Newman, MAC, Yandi and Pilbara iron ore), the physical and chemical properties and high-temperature properties were investigated in detail, to master their behaviour and effects in sintering, blast furnace, and non-blast furnace processes. Then, according to the individual properties of Australian iron ores, Chinese domestic iron ores and Brazilian iron ores, etc, the optimisation of ore-proportioning for sintering, blast furnace, and non-blast furnace processes was studied based on the interaction of the individual iron ores and their complementary properties, and the corresponding tests were carried out. The test work results indicated that this method not only improved the technical and economic indexes of sintering, blast furnace, and non-blast furnace processes, but also increased the addition of Australian iron ore. All of these provide the theoretical basis and technical support for highly effective use of Australian iron ore resources in iron and steel enterprises in China.

Jul 11, 2011

The knowledge in the field has been reviewed by literature studies, and using experience from personal research in sublevel caving. There is a lot of material regarding gravity flow of fine grained materials in bins, but the theory of flow for these materials are normally not applicable for coarse blasted rock. This study was therefore concentrated towards coarse rock fragments created after blasting in orebodies. The goal for this study was to make a report of known knowledge, and identify what we have to learn more about. The Bergmark-Roos theory, which was a paradigm shift in the science of gravity flow, is today the best mathematical theory for calculation of the drawbody for a homogenous material or when we wish to simulate the mean drawbody for a large number of draws. The Bergmark-Roos theory must however be improved, so it can take into account the flow pipe effect. When this is done it will be possible to construct a 3D computer model for calculation of ore extraction versus amount of loaded ore and waste. It is also necessary to find the 3D shape of the flow cone to be able to calculate the 3D ore rest that normally develops on footwalls. Calculations should be done for the draw on several sublevels including determination of the ore losses and temporary ore rests. First when this computer model is developed optimisation of ore recovery and waste rock dilution can start for a given orebody. The author points out the importance for international co-operation and standardisation of methods for determination of material properties. More field tests and model blasting tests should also be done. When enough knowledge is gathered, a handbook of the optimisation of sublevel and block caving should be written.

Jan 1, 2000