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By R Ballantyne, M Adams

Time Usage Models, used as a basis for calculating performance indicators for mobile mining equipment, have developed from very simple to very sophisticated models. This development has paralleled the increased collection and analysis of production data that itself has been enabled by the evolution of underground voice and data communications along with the relevant information systems. A Time Usage Model divides the hours that equipment is (or is not) used into standard components, by a hierarchical breakdown, so that measures of productivity can be used to compare performance of both people and equipment. The calculation of equipment availability, and thus the underlying Time Usage Model, has always been an extremely emotive topic as different groups use time usage information for different purposes. The direct link between measuring performance Key Performance Indicators (KPI) calculated from these models and employee rewards impacts upon the workforce. This paper discusses the conflict in use by various stakeholders and proposes ways to address some of the more contentious issues each supported by case studies. The simple status code functionality used by early systems has proven inadequate, leading to the evolution of “work-arounds”. These workarounds have become the norm and unfortunately have become embedded in the next generation of models and the information systems that incorporate them. This paper contends that the industry should stop building Time Usage Models to accommodate shortcomings in proprietary systems, but rather collaborate with suppliers to develop innovative methods to deal with the fundamental requirements. There are many points of differentiation that are not clear-cut. Pitfalls are discussed as well as threats to success. A framework of rules is developed as guidelines for how a Time Usage Model should be developed and applied. This will hopefully stimulate the on-going discussion as to how Equipment Availability and other components of the model should be calculated.

Mar 15, 2021

By J E. Moffatt, N A. Spooner, T J. de Prinse, D J. Ottaway, E Klantsataya, L d. S Teixeira, B W. Smith, T B. Payten, G Tsiminis

Single wavelength fluorescence sensing has been used in the preconcentration of ores for many years in situations where it is typically specific to the mineral of interest. Examples of fluorescence sensing include the sorting of diamonds in diamond mines and the sorting of scheelite in tungsten ores. However, the number of minerals that show useful single wavelength fluorescence properties in the visible spectrum is relatively small, so the application of fluorescence sensing is currently limited to niche application in the minerals industry. Recent developments at the University of Adelaide have focussed upon extending fluorescence signal measurements into the infrared spectrum, as well as investigating multi-wavelength fluorescence known as up-conversion fluorescence. These techniques may not only significantly increase the number of minerals that exhibit fluorescence properties suitable for both identification and sensor-based sorting, but also provide mineral-specific signatures of higher quality than previously attainable. This paper details the research work carried out by the University of Adelaide and funded by CRC ORE to develop a mineral-specific fluorescence sensor. The sensor targets two fluorine bearing minerals, fluorite and fluorapatite, that are common in many base metal ores such as porphyry copper ores and silver/lead/zinc ores. Fluorine is a known penalty element in mineral products derived from these ores, so mining companies need to monitor and control the amount of fluorine in their final product to keep it below commercially agreed specifications. Currently there is no real time sensor capable of monitoring fluorine in the ore feed so monitoring and control is carried out using time-consuming standard sampling and off-line laboratory measurements. The development and application of a real time fluorine sensor will enable the mining companies to monitor and control fluorine levels in the plant, greatly reducing the time and cost associated with producing their mineral concentrates within the prescribed specifications.

Nov 10, 2020

By D Pearce

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By D Elmo, M Scoble, Y Liu, B Klein, J Scholar, S Nadolski

A cave-to-mill study being conducted at the New Afton block caving operation demonstrated the potential for sensor-based ore sorting equipment to reject waste and improve the grade of feed to the mill. The lack of selectivity and potential for dilution entry associated with the block cave mining method results in many caving operations having to mine and process material that is below cut-off grade at certain stages of production. Online monitoring and bulk sorting systems have the potential to alleviate this problem and improve the productivity of caving operations while reducing energy and water requirements for each tonne of concentrate produced.As part of the cave-to-mill study, the suitability of a range of sensors, such as X-ray fluorescence and induction-type sensors, to sort mine production at the New Afton mine was investigated. Results showed that the discrimination of ore and waste can potentially be carried out by implementing surficial sensors into the material handling system. The study also showed that a combination of sensor outputs could be used to identify a certain ore type so that pre-emptive changes can be made in the mill to improve beneficiation performance. Overall, the outcomes of the study on implementing sensor systems at block cave mines are considered to be of significant relevance to a number of existing and future caving operations.CITATION:Nadolski, S, Klein, B, Elmo, D, Scoble, M, Liu, Y and Scholar, J, 2016. Investigation into the implementation of sensor-based ore sorting systems at a block caving operation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By E Jak

A viscosity model has been developed for both completely liquid and heterogeneous, partly crystallised slags in the Al2O3-CaO-æFeOÆ-SiO2 system in equilibrium with metallic iron. The Urbain formalism has been modified to describe the viscosities of the liquid slag phase over the complete range of compositions and a wide range of temperatures. The Roscoe equation has been used to describe the effect of presence of solid suspension (slurry effect) on the viscosity. The parameters of the viscosity model were optimised to describe large experimental data set in the low-order subsystems, as well as in the multi-component system. The computer package FACT was used for prediction of the proportion of solids and the composition of the remaining liquid phase. The model provides a good description of the experimental data (over four thousand experimental points) in liquid phase, and liquid + solid mixtures, over the complete range of compositions and a wide range of temperatures. This model can now be used for viscosity predictions in industrial slag systems. An example of the application of the new model to slag cleaning and reduction smelting processes is given in this paper.

Jan 1, 2000

By Lewis W. H, Leigh M. C, Mayercheck W. D

The U. S. Department of Interior's Bureau of Mines, in conjunction with a cooperator in the U. S. A., are developing a new highwall mining system (HMS) for coal extraction in unreclaimed and active contour strip mines. This prototype system is comprised of a computer-based remote control (CBRC) system to monitor and remotely control a thin-seam continuous miner (TSCM) and a 76*m long multiple-unit continuous haulage (MUCH) conveying system, plus other manually- operated support equipment located on the highwall bench. The TSCM and MUCH coal haulage system are both controlled remotely by a single operator in a protective enclosure at an ergonomically- designed workstation located on the highwall bench. Two other personnel work on the bench to operate other support equipment. Full-scale mock-up fabrications were employed in the design of the unique remote control operator workstation. The HMS should allow the safe and economical exploitation of increased coal reserves where they outcrop in hilly regions of the United States. It should also be competitive with conventional auger mining and other coal extraction techniques, with a productivity goal at a highwall site of 20 tonne/man-h. Extensive simulated surface tests of the miner and haulage system should be completed in early 1988 at Bureau test facilities at Pittsburgh, Pennsylvania. These will be followed by actual coal production trials of the entire system in 1988 at a highwall site in West Virginia/USA.

Jan 1, 1988

By D von Horn

Mineral sand orebodies are typically mined for their TiO2 content. Increasingly over the past 30 years, the major mineral focus has shifted from natural rutile to ilmenite and an acceptance that the latter generally needs some form of upgrading for economic conversion into TiO2 pigment. This upgrading obviously has a cost, and in conjunction with diminishing mineable feed grades, results in higher cost TiO2 units for chloride route Pigment Plant feedstocks. The net cost of feedstock can be significantly influenced by the recovery and sale of accessory minerals and by-products from the processing chain to the extent that some producers have the potential to achieve a zero net cost. Whilst slagging plants typically reduce net cost from rutile, zircon and pig iron revenues, operations supporting Becher type synthetic rutile operations have been limited to revenues from rutile and zircon only. A range of alumino silicate minerals show industrial potential, as does activated carbon, iron oxide and gypsum, by-products of the synthetic rutile process. Tiwest is a good example of a company maximising revenue from the accessory minerals as well as from by-products of the synthetic rutile process.

Jan 1, 2001

Over the last thirty years production of heavy minerals from Australian deposits has dominated the world market. The main incentive has been to suoply the raw material for titanium dioxide based pigments. These ~ninerals include ilmenite, rutile, leticoxene and more recently, synthetic rutile. Inevitably the viabilit/ of developing placer type deposits has seen influenced by other heavy minerals present, such as zircon and monazite, but these have been of secondary importance. For most of the sixties and seventies, Australia supplied the 'najority of free world rutile and zircon, and a large proportion of the ilmenite. With the run-down of rutile- rich reserves in eastern Australia, the emphasis has s:iifted in several countries, including Australia, to fill }the gap with i l Wen i to and its derivatives, leucoxene, synthetic rutile and titanium rich slag. over the next 15 - 20 years, as high grade beach placers in Western Australia are mined out, less traditional sources for mineral sands products will be opened up. Low grade placers (particularly those dominated by ilmenite) will be reassessed in Australia, U.S.A., Africa and Asia, and exploration will shift from beach and dune environment, to heavy mineral concentrations in alluvials, lake deposits and continental shelf deposits. At the same time, production of anatase and bastnaesite will be expanded, as required, from the huge resources contained in carbonatites in 3razil, U.S.A. and China.

Jan 1, 1986

Carbonate replacement tin deposits in the areas studiedhere are genetically related to biotite granites. Biotite in the granites is distinguished by distinctive compositional features. High MgO content is found in biotite in the Renison Bell granite; high MnO and A1203 contents in the Gejiu granite; and high FeO content in the Xinlu granite. The compositional features of biotite in the granites are reflected in skarn minerals formed around the granites.Granites associated with these tin deposits are characterized by different accessory minerals. Magnetite-bearing granite in the Xinlu deposit is related to the andraditic garnet (andradite 40-45 mole%)-hedenbergite skarn, with tin mineralization occurring in the contact skarn only. The sphene-bearing granite in the Gejiu deposit is related to the grossular garnet (grossular 50-60 mole%, almandine 20-30 mole%) -salite skarn, with tin mineralization occurring in the contact skarn, as well as stratabound replacement orebodies in the distal skarn. The ilmenite-bearing granite in the Dachang deposit and the Renison Bell deposit is related to the grossular-diopside skam, with tin mineralization occurring 500-1500 metres vertically and 1.5-3 km horizontally away from the granite contact.

Jan 1, 1990

By G Reynolds, N A. Ware, L Lu

Queensland Pacific Metals (QPM) is progressing its Townsville Energy Chemicals Hub (TECH) project to produce nickel and cobalt sulfates for advanced battery materials. Apart from the nickel and cobalt sulfates, the process also generates a hematite by-product (~640 ktpa). The hematite byproduct precipitated from the process, hereafter ‘hematite precipitate’, is high in Fe and particularly low in impurities. However, it is a fine <20 μm crystalline, hydrometallurgical precipitate and is produced as a filter cake containing a high moisture content of about 15 per cent. This is considerably different from natural hematite ore and is expected to change its performance during sintering. In the present study, laboratory scale sintering tests were undertaken to evaluate the potential impacts of substitution of the hematite precipitate for traditional magnetite concentrates and further for Australian hematite-goethite ores in a simulated industry base blend. Substitution of hematite precipitate for magnetite concentrates was found to slightly increase the sintering temperature required to achieve the strength of laboratory sinters. However, further substitution of hematite precipitate for Australian hematite-goethite ores slightly reduced the sintering temperature required to achieve the laboratory sinter strength. These results reflect the reduction in Al2O3 contents of the blends and are consistent with the trend observed in industry and pilot scale facilities. The reduction in sintering temperature generally correlates to a reduction in fuel rate in the larger scale sintering process. The pore structure of selected laboratory sinters was further examined and discussed in conjunction with sinter strength. The pore structure images highlighted the relative difference between the blends with the most obvious difference being seen at 1290°C which correlates well with the laboratory tumble index (TI). The laboratory sinter samples showed an increase in porosity and irregularity of pore shape, as hematite substitution increased demonstrating the correlation between a more porous structure and a lower TI.

Sep 18, 2023

By S J. Henderson

Over much of Australia, rainfall is highly seasonal and storm-driven. Consequently, operational mines often need extensive earthworks – drains, dams and levees – for protection during the occasional large floods and for water storage against the dry times; however, it has not been appreciated that many of these earthworks will need to function after mining has finished, sometimes, beyond a normal design life for engineered structures.While a mine is operating, standards for design and maintenance are dictated by regulation and risk assessment. For dams and levees – regulated structures – the standards imposed mainly relate to life-of-mine. The levels of risk and maintenance accepted by the mine operator may not be acceptable to another landholder in perpetuity. However, the Environmental Authority cannot be surrendered unless the landholder has accepted responsibility for any unrehabilitated regulated structures (Department of Environment and Heritage Protection (DEHP), 2016).In order for a future landholder to be willing to take responsibility for a dam or levee, the structure should be of value to the business of the property. In addition, its management needs must be consistent with that business; for example, it should be maintainable using skills, equipment and materials normally available to the business.CITATION:Henderson, S J, 2016. Earthworks or landforms? Designing for lease surrender, in Proceedings Life-of-Mine 2016 Conference , pp 151–153 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Collins BJ

Basic principles of stack injection are outlined and supported by calculations of thermal, chemical and aerodynamic requirements of an ideal 4000 tpd furnace. Calculated results show that these requirements vary with conversion of FeO, and that best performance may be expected with XFeO = 1.0 for which calculated production is 6919 tpd and coke rate is only 211 kg/thm. Calculations are also presented for a cycled injection. Discussions show that stack injection is a good way of overcoming softening problems and meeting the demand for iron in a fluctuating demand situation when it exceeds the maximum capacity of a furnace.

Jan 1, 1975

By M Zhu, G Tranell, J You, K Tang, X Ma

The thermal conductivity of slag is critical for the efficiency of high temperature metallurgical processes such as the smelting reduction of ferroalloys, the ladle refining and the continuous casting mold flux in steelmaking. Experimental determination of slag’s thermal conductivity is fraught with challenges, as seen in yielding data for the SiO2-Al2O3-CaO system that are often inconsistent and widely dispersed. In molten slags of this system, thermal transport occurs via phonons within the network structure. To quantitatively describe thermal conductivity based on the microstructure, hightemperature Raman spectroscopy was employed to measure the silicate tetrahedra Qi (i = 0, 1, 2, 3), with Q4 species inferred from mass balance. This study also integrated molecular dynamics simulations to provide a fundamental understanding of the microstructure units distributions. Machine learning algorithms, especially deep neural networks, were applied to establish the relationship between slag composition and the configuration of tetrahedra. The thermal conductivities were then connected with silicate tetrahedra Qi using an Arrhenius-type formalism. This study sets the stage for extending our findings to more complex, multicomponent slags, enhancing their practical application in industrial processes.

Aug 21, 2024

By Cripps-Clark CJ, Deague TK

In order to study conditions under which SiO(g) may be formed in a blast furnace, equilibrium phase diagrams were constructed for the combustion of high and low ash cokes with oxygen-enriched blast and oil injection under conditions of high and low raceway pressures. Free energy minimisation techniques were used to calculate the composition of gaseous and condensed phases. Where coke ash is assumed, for simplicity, to comprise Si02 only, the coke can be comple- tely gasified, mainly to SiO and CO, under restricted conditions of coke to blast ratio and at temperatures greater than 1600 - 1650¦C, depending on system pressure. The formation of SiO(g) is partially suppressed by the introduction of alumina into the ash, because of the formation of solid and liquid alumino- silicate compounds. The minimum temperature for complete silicon gasification is raised to about 1700¦C. The results of the equilibrium calcula- tions are related-to actual raceway conditions. It is proposed that virtually all silicon in the coke ash is gasified such that, on condensation, it affects hot metal chemistry and slag properties and secondly, that the effects will be greater with higher ash cokes.

Jan 1, 1980

By K Nakashima, K Aya, T Sumita, N Saito

Electro slag remelting (ESR) is one of the methods used to produce high-cleanliness steel. In the ESR method, the product steel electrode is immersed in flux, and the electrode is melted by the Joule heat of the flux generated by high current. CaF2-based melts are mainly used as fluxes, but the electrical conductivity of CaF2-based melts varies widely among researchers and measurement methods. Therefore, this experiment aims to measure the electrical conductivity of CaF2-based melts based on the van der Pauw-Ohta method, which does not require the cell constant that is a fundamental error factor in electrical conductivity measurement at high temperatures. The measurement temperature was set at 1450–1600°C, and dehydrated Ar flowed through the furnace at 200 mL/min. Electrodes were fabricated by Pt-30mass per cent Rh alloy, and the electrodes were connected to an impedance analyser using a four-terminal probe. The electrodes were immersed in the melt, and the impedance and phase angle were measured by AC frequency sweep (50 Hz to 200 kHz). The electrical conductivity was then calculated by utilising the impedance’s real part values when the impedance’s imaginary component was zero. The electrical conductivity showed a positive temperature dependence. The electrical conductivity of 60(CaO⋅Al2O3)-40CaF2 melt increased with increasing temperature but was found to be roughly one-third of those of the previous studies. In the conductivity measurement of 60(CaO⋅Al2O3)-40CaF2 melt, the AC frequency with a phase angle of 0° was found to be different depending on the temperature and immersion depth. By sweeping the frequency, the impedance at the phase angle of 0° can be obtained, which enables us to measure the electrical conductivity more accurately.

Jun 19, 2024

By Rosentreter N

Difficulties with froth flotation recovery and vacuum de- watering equipment for the treatment of fine coal have been investigated. Mechanical alterations to cyclone desliming banks, and flotation cells are described. A large disc filter has been replaced by two drum filters for dewatering, and the improvement in plant. operation is discussed:

Jan 1, 1978

By E U. Petersen, D R. Cooke

Hydrogen and oxygen isotopic constraints on hydrothermal fluid composition from the Pliocene Boyongan and Bayugo porphyry copper-gold deposits (southern Philippines ) reveal mixing of magmatic and sea water reservoirs as the hydrothermal system evolved. Magmatic-equilibrated fluids (d18O: +8.3ë to +9.1ë; dD: -61ë to -51ë) are represented by hypersaline brines implicated in copper-gold transport and deposition. These dominate the fluid inclusion assemblage in early comb-quartz (unidirectional solidification textures), miarolitic quartz, and in K-silicate-stage quartz-K-feldspar ¦ biotite veins. Fluids responsible for post-K-silicate alteration assemblages of pyrite-clay (illite, pyrophyllite and kaolinite), alunite and smectite are represented by low-moderate salinity two-phase inclusions in co-existing quartz. These are interpreted as mixtures of evolved magmatic fluids (d18O dD: -42ë to -20ë) with evolved Pliocene sea water (d18O: + 4.0ë; dD: +4ë). The isotopic evidence for sea water involvement in the hydrothermal system suggests that porphyry emplacement and associated diatreme formation could have occurred in a submarine setting. An&nbsp;EXTENDED ABSTRACT&nbsp;is available for download. A full-length paper was not&nbsp;prepared for this presentation.

Jan 1, 2008

Pipe Jacking has been a recognised method of tunnelling in the U.K. since the early 1950&apos;s, although I understand that pipes were pushed blind by the soldiers in the first World War from trenches on the Allied side to, or adjacent to, trenches on the German side, thus allowing explosives to be used with a certain element of surprise! &apos;However, on its more conventional to the U.K. in the 1950&apos;s, Pipe Jacking made considerable inroads into the tunnelling market place as an alternative to timber supported headings. This success was, unfortunately, fairly short lived because, owing to its simple method of operation, contractors paid insufficient detail to the engineering (or surveying) aspects and as such the system soon had a bad reputation for unreliability and lack of accuracy. Due to these failings, the market was not exploited and, therefore, there was a lack of investment by contractors, pipe manufacturers and also by any client, or research organisation, which is client associated. The effect of this meant that the system stagnated for a number of years and was used generally only for short crossing work (i.e. railways, canals and motorways), and then only in good homogeneous ground. Albeit, a limited number of full scale sewage disposal contracts were carried out, but with the lack of knowledge and experience of the clients, contractors and suppliers, (particularly the pipe suppliers), no reasonable success, either physical or financial, was achieved on any such contract.

Jan 1, 1987

By H J. J Boshoff

Mine closure planning integrated into life-of-mine (LOM) planning during the operational phase consists of many subcategories. One of these subcategories that needs to be fully integrated into the LOM planning is that of water management planning. Issues arise when mine water management infrastructure, which is required post-mine closure, is only considered closer to the end of LOM. Once the mine is closed monitoring is focused on water quality as an indicator of closure performance, hence inadequate upfront post-mining water management planning or integration into operations will result in environmental harm. The lack of considering post-mining water management is not uncommon in LOM planning. Poor mine site water management and planning are a wide reaching problem for the mining industry. Numerous active mines have been issued with environmental notices and penalties for contaminated water discharge; including issues with abandoned mines now being cared for by governments all over the world.Mitigating sources of water contamination caused by existing and closed mine sites that are leaching pollutants might be impractical, due to inaccessibility to the contaminants or final landform topography. The opportunity to consider and introduce post-closure required mine water management infrastructure is lost once the waste facilities are constructed. Mitigating contamination is made more problematic with mines located in remote areas, serviced by dedicated roads, water supply, electrical supply, etc. It is expected that these services will be decommissioned or drastically reduced, once closure is reached making remedial work much harder. Inadequate planning, to ensure access and easily maintainable water management infrastructure, could lead to erosion and contamination going unnoticed. There are numerous examples of poor mine water management practices in Africa, Asia, Australia, South and North America. In the United States more than 23 000 km of streams are affected by pollution sourced from some 50 000 abandoned or mature mine sites (DeGraff, 2007).CITATION:Boshoff, H J J, ?2014. Inadequate water management planning resulting in long-term closure liabilities, in Proceedings Life-of-Mine 2014 , pp 233–246 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

Australia is presently the world&apos;s principal producer of rutile and zircon, and also provides a major share of the world&apos;s ilmenite. Since 1980, Australia&apos;s share of the world&apos;s output of these minerals has fallen. Exhaustion of known resources, together with the changing composition of new deposits, is expected to result in Australia&apos;s share of the rutile and zircon output continuing to decline. Its role as a major supplier of upgraded ilmenite, that is synthetic rutile, is expected to increase. In 1994, the Bureau of Resource Sciences assessed Australia&apos;s demonstrated resources of mineral sands as follows: rutile 14.4 Mt, ilmenite 132.5 Mt, and zircon 21.0 Mt. These resources are located along the coast of Queensland and New South Wales, in the Murray Basin of New South Wales and Victoria, in the southwest corner of Western Australia, and in the Eneabba region, north of Perth. However, some 45 per cent of rutile and zircon resources along the coast of Queensland and New South Wales are not available for mining because of environmental concerns. World demonstrated resources are estimated at 40 Mt (contained TiO2) for rutile, 50 Mt for zircon and approximately 312 Mt (contained T1O2) for ilmenite. Outside of Australia, the most important resources of rutile, ilmenite and zircon are in South Africa (rutile, zircon , and ilmenite in the form of titania slag), Sierra Leone (rutile), India (ilmenite, zircon and rutile), and Canada (hard rock ilmenite). Significant resources of ilmenite occur in Madagascar and Mozambique.

Jan 1, 1996