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By M D. Griffith

Oct 12, 2022

By D E. Thorp

The mining and concentration operations of New Zealand Steel have been carried out initially from the Waikato North Head (WNH) deposit since 1969 and subsequently from the Taharoa deposit since 1972. Over the years the WNH operation has produced about 1.2 million tonnes of concentrate which has been converted into steel, while total exports to the Japanese Steel Industry from Taharoa reached five million tonnes in February of this year. Recent expansion plans both in domestic steel production and in the ironsand concentrate export market have made it necessary for the company to look closely at, among other areas, the mineral processing of the titaniferous ironsands in both deposits. This paper deals with the recent test work carried out at WNH and Taharoa on the use of the cone concentrator unit as a primary gravity concentrating unit ahead of the magnetic separation stages and as a cleaner concentrator following the primary magnetic separation.

Jan 1, 1977

By A R. Hollis, M Heddon

The safe life cycle of a Tailings Storage Facility (TSF) is founded on the fundamentals of proper design, construction, operation and closure. Leinster Nickel Operations (Leinster) utilises four active TSF cells that are cycled between filling (deposition), desiccation, and construction to meet a targeted rate of rise. This results in ongoing and consistent raising of the TSF walls. Critical to maintaining the safe life cycle through this consistent wall raising is precision construction and high frequency quality assurance to ensure compliance to design requirements and TSF walls free from defects. Leinster has recently deployed Intelligent Machine Control technology for TSF construction. Advances in Intelligent Machine Control have decreased variability in construction; ensuring variations are within the tolerances of design. The Intelligent Machine Controls are programed to ensure construction conforms to design tolerances of +/-30mm. This level of accuracy provides assurance of borrow area set out, compacted layers are as per design, compaction monitoring is within the zone placed, scarification between layers to prevent lamination is maintained, and batter angles are set to the correct grade. This level of control provides certainty that construction meets the design intent. In conjunction with Intelligent Machine Control, periodic drone surveys are conducted to verify construction against design. Advancement in survey equipment and techniques allow higher frequency, high accuracy survey to be completed on demand by site based personnel. This provides quality assurance through all stages of the construction phases, as well as the final constructed wall, ensuring compliance to design. Combining Intelligent Machine Control with higher frequency quality assurance provides an increased level of certainty that the TSF construction is defect free and within quality specifications. These recent technological advancements in Construction and Quality Assurance ensure cell raises are constructed to the design intent with greater levels of accuracy and precision than ever before.

Jul 1, 2021

By Andrew R. L

The Kintyre uranium deposit was discovered in 1985 in the course of following up radio- metric anomalies generated in an earlier air- borne survey. The latter survey was conducted primarily to acquire aeromagnetic data for diamond exploration and the uranium discovery was made during a subsequent campaign of base- metal exploration. CRAE commitment to the Rudall area for a range of commodities over a period of 13 years made a significant contrib- ution to the discovery of Kintyre. Other con- tributing factors included CRAE's multicommod- ity approach to exploration, management support and continuity in the geological team. The Kintyre uranium deposit (Fig. 1) is located on the northern margin of the Rudall Metamorphic Complex, 60 kilometres south of Telfer and 260 kilometres north northeast of Newman, in the Paterson Province of northern Western Australia. It is 700 metres inside the northern boundary of the Rudall River National Park (15695 sq. km) and lies between the Great Sandy Desert and the Little Sandy Desert (Beard, 1969). Intense weathering since the Permian has produced a subdued landscape around the deposit. Resistant rock types still retain an older plateau surface but it is incised by more recent streams. Other Proterozoic and Permian rocks form low, sometimes rocky, areas largely covered by aeolian sand.

Jan 1, 1988

By M Haest, S Sandler, R Botha, H Lang, K Hume

Benchmark practices in the mining industry include the establishment of Quality Programs — Quality Assurance and Quality Control (QAQC) — to monitor the correct execution of sampling protocols and control each stage of the ‘Sample Cycle’: Sample Collection, Preparation (comminution) and Analysis. QAQC reports commonly include statistical-numerical results that quantify performance of QAQC controls (field duplicates, preparation duplicates, blanks, standards etc). Graphics such as scatter plots, QQ plots, histograms and cumulative frequencies are used to represent the results. Statistical values including relative difference, absolute difference, relative variance, averages, T-test, and Zscores are used to quantitatively express the relationship between duplicate pairs ... but is an effective quality program just a statistical exercise? This paper aims to highlight the concept of ‘Quality Management’ (QM) as the precursor of continuous monitoring (ideally in real time) of QAQC results on Exploration, Production, Processing and Port samples, determined by trend analysis performed on a time and/or grades basis. Currently, there is a paradigm in the process of quality assurance that if individual data points fall within a predetermined acceptance limit then they are ‘acceptable’ and therefore suitable for informing operational and investment decisions. However, what is stated with respect to QM is that sometimes results found within the acceptance limits can indeed be internally biased, or show material deviations over a period of time, thereby impacting reconciliation results and/or potentially creating discrepancies with the final buyers. QM refers to the proactive detection of these ‘anomalous tendencies’, the approach and communication with the source of the information, the understanding of the reasons that cause the deficiencies, and the generation of agreed action plans to remediate the situation and ensure the consistency of results, in other words: continuous improvement on proactive manners.

Mar 22, 2022

With the burgeoning opportunities for new gold mines to be developed the opportunity now exists for a reassessment of the optimal processing path for these gold ores. Projects have traditionally followed the path of whole ore cyanidation with either Carbon In Pulp (CIP), Carbon In Leach (CIL) or Merrill Crowe. The challenge ahead is whether these traditional processing methods are the best option for stakeholders, or to go beyond CIP and use a combination of currently available technologies that can be used to provide gold recovery at a significantly reduced capital cost and minimal deleterious impact on the environment. Either stand alone or combinations of gravity concentration and flotation, can produce a gold bearing concentrate that can then be fed directly to a batch or continuous intensive cyanidation unit. Treatment of a gravity/flotation concentrate by intensive cyanidation may be processed by the InLine Leach Reactor (ILR) developed by Gekko Systems of Australia. The advantages of the technology combining gravity/flotation followed by intensive cyanidation are significantly reduced capital costs; improved safety due to reduced cyanide inventories; the majority of tailings un-contaminated by cyanide; less energy required due to an opportunity for an increase in grind size û reducing green house gas emissions; detoxification of concentrate tailings can minimise tailings disposal and containment requirements.

Jan 1, 2004

By P Corbett, P Sheffield

Centennial Coal operates the Springvale longwall mining operation which extracts coal beneath the Newnes Plateau in the Western Coalfields of New South Wales. Springvale, and the neighbouring Angus Place mine, have a history of difficult geotechnical conditions where combinations of a relatively high stress regime and weak, laminated roof and extensive geological faulting has led to numerous roof failures throughout the mine’s life. Following development, the mines underground roadways can experience high levels of roof movement which may lead to roof falls. Multipoint wire extensometers are extensively used throughout the mine for roadway condition monitoring, and to reactively drive remedial strata support through trigger action response plans (TARPs).As a result of the use of high-density extensometer monitoring over a long period, the mines have an extensive archive of legacy data. Data processing has evolved over time in order to accommodate the increasing data volume, including direct data entry from the recently introduced hard-wired real-time monitoring instruments. It is likely that telemetric real-time instruments will be introduced in the future, which will cause another step change in data management requirements. This paper discusses the transition to and evolution of relational database management systems for extensometer and associated data.This paper also presents case studies of the use of a new software tool for reprocessing legacy data to enable time-scaled visualisation of monitoring data in the context of longwall and development face positions and installed strata support. The software can be used proactively in the identification of geotechnical risk factors and their interaction with the mining process to allow a more robust geotechnical hazard process. It interfaces directly with the widely used ExtoChart database software and can be presented with scale drawings of geological and geotechnical data to allow correlation of monitoring data results with risk factors.CITATION:Corbett, P and Sheffield, P, 2015. The use of high-intensity monitoring data to better characterise geotechnical properties of a non-homogeneous rock mass, in Proceedings Third International Future Mining Conference, pp 145–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Sorokin M. L, Komkov A. A

Flash smelting of nickel sulphide concentrate has been practiced at WMC's Kalgoorlie Nickel Smelter for 20 years. The mineralogy of the concentrate from the original mines was particularly suited to this process. However, taking a strategic view, potential new processing routes should be fully evaluated as possible replacements for the current technology. The Vanyukov process has been under development in Russia for the past 40 years and has been successfully applied on a large scale to the smelting of copper concentrates, at two locations - Norilsk and Balkhash. The potential for the application of the Vanyukov process to the smelting of nickel concentrates offers a number of processing advantages, including smaller reactor and decreased dependence on fuel oil. This paper reports on preliminary investigations into the application of the Vanyukov process to the smelting of nickel concentrates. At this stage the investigations are limited to semi-quantitative comparisons and modelling studies.

Jan 1, 1992

By H Kurth

Oyu Tolgoi copper and gold mine in the southern Mongolia holds mineral resources that make it one of the largest known copper and gold deposits in the world. The project is operating an open pit mine on the near surface of Southern Oyu deposit and developing underground block-caving mine at the Hugo Dummet North where 80 per cent of total resources exists. Oyu Tolgoi (OT) commenced open pit mining in 2011 and implemented an industry standard blasthole sampling, and ordinary kriging grade control estimation with block-out process. Since 2017, grade control improvement projects have successfully completed that have led to the implementation of current, improved grade control system. Geological model is updated by blasthole logging on Leapfrog® and used for daily grade estimations. GC estimation is proceeded solely on Vulcan® by running Lava script and integrating with a relational database. Combination of block-out procedure produces GC model which is updated in Vulcan® and as well as in the database simultaneously. Switching to the integrated database eliminated many manual processes such as importing and exporting data and enabled access to the database anytime, anywhere and from any device. Thereby, these improvements allowed to increase an efficiency, create a comprehensive reconciliation system and reduce operational risks. We are looking forward to expanding applications of integrated grade control data stored in the database. This paper outlines how the grade control system was developed at OT’s open pit mine, and how it is integrated into the short range mine planning, mine reconciliation workflow and ultimately enabled development of various automated reporting systems.

Mar 22, 2022

The most appropriate technology needs to be applied to premining geological investigations to achieve reliable data for predictions of geological conditions ahead of mining. The paper describes the application of various investigatory techniques in BHP's Illawarra Collieries which are used to provide reliable assessments of structure, the nature of the coal and surrounding strata,, and the fluids contained in the strata. The techniques used include surface seismic, in-seam seismic, borehole drilling, electromagnetic and aeromagnetic surveys, hydrogeological investigations and in-mine mapping. The results of various case studies are presented as examples of the application of techniques.

Jan 1, 1988

By M Hawkes, Z Ji Gang, Z Ming, R Hassell

As underground mines become more geotechnically challenging with increasing depth and excavation size, the requirement for ground support to be installed as per design becomes more critical. The verification of installation quality for cable bolts and grouted rock bolts is difficult to assess. Current methods to control quality have limitations; pull testing is largely inconclusive with only extremely poor installation being identifiable. Audits during installation can only capture a small percentage of installed bolts. Following large rock mass displacement from either squeezing ground or seismic events, even previously well installed bolts may have yielded and require replacement. A method to provide an improved understanding of the reinforcement installation quality is Non- Destructive Testing (NDT) using acoustic reflection. To validate the accuracy of an NDT system, both plain and bulbed strand cable bolts were grouted in clear plastic tubes. The encapsulation grout quality was deliberately varied from full encapsulation through to partial encapsulation and a range of different size voids. The clear tubes allowed the ground encapsulation to be observed. Cable bolts strands were cut at varying lengths and different water cement grout ratios were used. Acoustic testing of the cable bolt specimens was completed blind; the technicians were not aware of what was being tested. The NDT results correlated well with the grout encapsulation, with differences between full encapsulation, minor voids and major voids being determined. The different water cement ratio and bolt lengths (including when partially cut) were also identifiable but with some discrepancies. Trials of the technology underground have also shown the data collection process to be relatively quick with each bolt taking 1-2 minutes to test, with interpretation of the results able to be completed soon after. The NDT results collected from the underground trial showed a wide variance in cable bolt grout encapsulation quality indicating that there were installation issues.

Mar 15, 2021

By Z Chang, S A. Mrozek, S Windle

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. It is important to understand skarn-porphyry transitions in order to use exposed skarns to look for associated and potentially larger porphyries. For such purposes, a good start is to understand the transition between porphyry and skarn in known deposits. In this contribution, we report the transition at Antamina, Peru, where skarns occur in and around a Miocene complex comprised of more than seven porphyritic intrusions. There are three types of skarn-porphyry relationships. The earliest intrusive phase, P1A, contains both endoskarn and porphyry-style quartz veins with secondary biotite halos. The porphyry quartz veins and endoskarns formed at the same time. Locally, the intrusion contains only endoskarn without porphyry quartz veins and is surrounded by exoskarns in carbonate wall rocks. In the third scenario, later porphyry (P2) intruding into P1A porphyry and skarns related to P1A contains abundant granular quartz veins and secondary biotite alteration but does not have significant endoskarn. The granular quartz veins also extend into earlier P1A skarns. The scarcity of endoskarn associated with P2 is related to the supply of Ca. The earliest P1A intrusion intruded into carbonates that supplied abundant Ca, therefore both endoskarns and exoskarns formed. In contrast, where the wall rocks of the later P2 intrusion are P1A or skarn related to P1A, there was little free Ca, therefore only porphyry-style quartz veins formed.CITATION:Chang, Z, Mrozek, S A, Meinert, L D and Windle, S, 2015. Skarn-porphyry transition – an example from the Antamina skarn, Peru, in Proceedings PACRIM 2015 Congress, pp 409–414 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Matsumura T, Takematsu T

The Brown Coal Liquefaction Process (BCL Process) has been developed by Nippon Brown Coal Liquefaction Co., Ltd. (NBCL), and a 50-ton-per -day Pilot Plant has been partially completed and put into operation by Brown Coal Liquefac- tion (Victoria) Pty., Ltd. (BCLV) at Morwell, Victoria, Australia. This Project has been sponsored by New Energy Development Organization (NEDO), an or- ganization associated with MITI, and has been promoted as a National Project with funding by the Japanese government. This project has also been conducted as a cooperative technology de- velopment project between the Japanese and Aus -tralian governments since 1980 and has been supported by the Victorian state government and

Jan 1, 1987

By M Haest, O Dominguez, D Mittrup

With the current focus in the mining industry on reducing costs, while simultaneously improving ore quality, infrared spectroscopy is a tool that can potentially assist companies to meet both challenges. Changes in the nature of infrared spectra are strongly influenced by changes in mineralogy, which is a key input variable for exploration (geology and orebody modelling and ore characterisation) and mining (pit design, mine scheduling and processing plant design/management).Infrared spectroscopic logging of drill holes has been embedded as a standard tool in BHP Billiton Iron Ore exploration, with a process set up to automatically deliver mineralogy and associated imagery to the end users (typically exploration geologists). The availability of consistent and automated mineralogy drill hole logs across a project is improving the output quality and reducing re-work.BHP Billiton Iron Ore is now looking into using the same infrared spectroscopic data for other applications, including improving predictions of geometallurgical and geotechnical parameters. Trials show that addition of infrared spectroscopic data to conventional data sets (element analysis and depth information) is significantly improving the accuracy of regression models to predict the lump-fine ratio.Further initiatives around infrared spectroscopic data in BHP Billiton Iron Ore include the installation of infrared spectroscopic sensors over conveyor belts, infrared spectroscopic mine face scanning and infrared spectroscopic blasthole logging. The ultimate vision is to have consistent, seamless mineralogical data from infrared spectroscopic sensing available throughout the mineral value chain (exploration/mining/processing). This seamless infrared spectroscopic data ‘bridge’ will allow the transfer of knowledge between the different sections of the value chain (exploration, mining and processing). For example, ore handle-ability could be predicted on exploration samples using regression models built from processing plant observations. In the opposite direction, information gathered about the buried stratigraphy by infrared spectroscopy utilised during exploration, could be used to predict the stratigraphy encountered during mining. This collaboration across BHP Billiton Iron Ore is expected to deliver significant savings, while improving the quality of the final product, thus helping to drive efficiency over the next decade.CITATION:Haest, M, Mittrup, D and Dominguez, O, 2015. Reaping the first fruits – infrared spectroscopy: the new standard tool in BHP Billiton Iron Ore Exploration, in Proceedings Iron Ore 2015, pp 277–284 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

This paper concerns a pragmatic approach to a problem that is common to many operations in the mining industry: how, over the short-term, to grasp the extent and distribution of long-term financial risk from environmental causes and reduce these risks strategically, in order to maintain stability and flexibility in the operations. Surprisingly, many companies operate without an environmental master plan or tools that can help managers measure and reduce financial risks. Such companies may be subject to unknown unacceptable financial risks from environmental causes. While many companies have some kind of internal system of environmental standards, it is often the case that such systems have uneven or limited effect, and offer no opportunities for visualising, measuring or managing aggregate financial risks from environmental causes. `Aggregate risks' are defined here as the calculated total expected financial costs to a company, or a subdivision of a company, from environmental causes at nominated operations over a defined time period. Aggregate risks take into account the type and magnitude of an environmental problem set, the likelihood of occurrence, and the time frame during which the problems will develop or solutions are required. For the large corporation, the 'amount of' aggregate environmental risk is a statistic that can be managed, along with other financial parameters, at the corporate level to improve the stability and predictability of operations, and protect the interests of shareholders. This paper concerns development of a management framework and a tool for the large corporation that responds to the need for managing aggregate environmental financial risks. The logical framework proposed to overcome the need for strategic vision is the Environmental Master Plan, and this is described in the next section. The analytical tool proposed to measure aggregate risks and provide relevant data and insights to managers, is called an Environmental Risk Management Information System, and its mechanics are described in a subsequent section.

Jan 1, 1994

By Johnson N. W, Manlapig E. V, Alexander D. J, Franzidis J. P

The importance of the froth region on flotation performance is often emphasised in the literature. It is well-known that decreasing froth depth or increasing air flowrate results in increasing cell recovery at the cost of lower concentrate gra

Jan 1, 1997

The Copper Concentrator at Mount Isa Mines Limited treats approximately 6 Mt of chalcopyrite ore annually. The ore is currently sourced from the 1100 and 3000 orebodies at Mount Isa. Chalcopyrite is the only significant copper bearing mineral, with pyrite, quartz and dolomite being major gangue minerals. Ore is typically 10% chalcopyrite, 11% iron sulphides and 79% non-sulphide gangue. Copper ore is treated through two autogenous mills, two ball mills and a flotation circuit. The autogenous mills replaced a crushing plant, two rod mills and two primary ball mills during 1991. For routine analysis of concentrator performance, composite samples of mill feed, final concentrate and tailings are generated every 4 week period. All samples are sized and size fractions are assayed. Recovery of mineral species to the concentrate are then calculated for each size fraction. Sometimes liberation analysis was also performed by QEM*SEM (Quantitative Evaluation of Material by Scanning Electron Microscope).

Jan 1, 1990

By R Goddard

An alternative stoping method has been adopted for narrow vein stoping at the Tasmania Mine in Northern Tasmania. Colloquially described as ‘Radial-in-Reef’ (RiR) stoping, the method employs the drilling of radial rings in the plane of the Reef from a drill stub located at the geographic centre of the proposed stope panel.Production from the Western Zone of the Tasmania Reef has been undertaken remotely from the Reef since 2007, after a detailed geotechnical engineering analysis indicated that the integrity of the sill drives could not guarantee an acceptable level of confidence should an anticipated seismic event occur within a radius of 10 m. The key tenet of the remote mining approach was the exclusion of personnel from sill drives once stoping had commenced. The remote mining method had to be ‘retrofitted’ to four existing stoping blocks totalling 11 sill drives which totalled 160 m vertically. The remote mining method proved to be complex, cumbersome and very expensive. However, the ore was extracted successfully.By early 2010, previously developed ore had largely been exhausted and the future development with an orebody open at depth presented the opportunity to review the current extraction method. However, the new extraction method needed to maintain the tenet of excluding personnel from sill drives of active stoping blocks, but seek opportunities to reduce the difficult and costly aspects of the previous method. The new ‘Radial-in-Reef’ stoping reduced the development requirement from six to two drives per ore block. Cost implications aside, the significant reduction in prestoping extraction ratio was expected to also reduce the likelihood of seismicity. Transverse production rings were designed to be drilled radially from a drill stub mined from a mid-stope footwall drive. Stopes totalling up to 7000 tonnes were planned be fired in a single electronic blast. Extraction was designed to take place from a basal sill drive under teleremote operation. At the time of writing, the method was under trial.

Mar 21, 2011

THE object of this paper is to offer some suggestions to assist metallurgists to supervise the operations of flotation plants. We do not yet thoroughly understand what "flotation" is or "why minerals float" and all attempts that have been made to explain the phenomena have been based on theory or imagination, and have not been capable of substantiation by practical demonstration, or even by laboratory tests; but it is wellknown that particular minerals will float in a liquid under certain specified conditions, and that some other minerals will not float under those conditions, and that, if a mixture of the two classes of minerals be subjected to those conditions, there will be separation of the minerals, of which one class will float and the other will remain unfloated as a residue. The duty of the flotation expert is to so control the operations and the conditions of the liquor as to obtain the best commercial result from the ore he is treating. The chief controlling factors in a flotation plant appear to fall under the following eight headings, all of which are important:1. Crushing.2. Rate and regularity of feed.3. Density of pulp.4. Temperature.5. Addition agents.6. Condition of circuit liquor.7. Agitation.8. Aeration.

Jan 1, 1920

By Windsor C. R, Thompson A, Bywater S

A new high tensile strength, steel cable, that may be grouted into boreholes has been developed for use as rode reinforcement. The manufacturing technique produces a birdcage pattern in which the cross section varies along the length of the cable. The load transfer from cement grouts to birdcage cables has been demonstrated in laboratory tests to be better than that of standard 15.2 mm diameter seven wire cables. The manufacturing process also allows for a wide range of capacities which may be specified by design engineers. The various birdcage cable configurations have been applied as rock reinforcement in a number of Australian underground and surface mines.

Jan 1, 1990