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By R Battison, R Duggan, S Esen, K Henley, P Dare-Bryan

Increased catch bench crest loss has been observed in recent years at Barrick’s Cowal Gold Mine situated in central New South Wales, Australia. A project was initiated to diagnose the cause of the crest loss, and evaluate ways to limit its effect on final walls.A range of different blast measurement techniques were utilised to evaluate the progressive damage caused to catch berms by presplit, production and trim blasts. Techniques employed included; single point vibration measurement, cross-hole seismic analysis, precision berm surveys, horizontal p-wave velocity measurements, crest loss volume calculation and water level changes between blasts.Blast measurements showed that the majority of damage to the catch berm was caused by the presplit blasts, which registered vibrations greater than 700 mm/s at 5 m behind the presplit line. As a result, considerable changes were made to the blast designs after a series of computer simulations via mechanistic blast modelling (MBM). The uncharged presplit collar was increased from 2 m to 4 m, and every second hole was left uncharged. Vibration modelling using a multiple seed wave (MSW) model was used to optimise trim blast delay timing. Burden relief was changed from 16 ms/m to 27 ms/m using one hole firing per 4 ms time window, and the initiation angle was changed from shallow to steep. These changes in the presplit loading and trim timing helped reduce catch bench crest loss by 1–2 m.Trim shots using a high strength bulk emulsion explosive were also identified as contributors to berm damage after analysis of blast monitoring and MBM modelling. The modelling study resulted in the generation of alternative blast designs to minimise the crest loss, including the use of low-density/low-velocity of detonation (VOD) bulk explosive product (Flexigel™ Advantage) in trim pattern designs. This was trialled on the Northern and Eastern pit walls to evaluate the damage to catch berms on final walls. The trials demonstrated that berm vibration was reduced significantly; fragmentation was similar (or slightly blockier) compared to the fragmentation using the old blast designs; displacement of the berm was reduced, so increased catch bench widths were attained. This paper summarises the trials, and presents a summary of the crest loss to date.CITATION:Battison, R, Esen, S, Duggan, R, Henley, K and Dare-Bryan, P, 2015. Reducing crest loss at Barrick Cowal Gold Mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 189–202 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By R Moller

Reconciliation at large iron ore operations is a complex and time- consuming process. Often the volume of data and the large range of different stakeholders makes the process almost impossible. Up until recently geologists and engineers at these operations would spend hours cutting and pasting data in and out of monster spreadsheets, diligently comparing how resource/reserve models, grade control and survey pick-ups compare to what was actually produced. In 2003 the Sishen Iron Ore Mine in South Africa broke this cycle by implementing SnowdenÆs Reconcilor software. The implementation of a dedicated reconciliation system required a number of existing practices to be changed, with the involvement of stakeholders right across the mine. Data sources had to be clarified and validated, terminology had to be standardised, processes needed to be documented and some methodologies needed to be updated. This was a task that required significant effort by Kumba personnel so that the system could be successfully implemented. This paper provides a case study of the reconciliation system implementation at Sishen. It is a story of an operation that evolved from using a number of fragmented reconciliation processes to using a unified automated system. This paper outlines the key estimates and measurements that are used for reconciliation, details the characteristics of an automated web-based information management system to facilitate the process and provides some insights about the benefits that have been gained though the use of a rigorous reconciliation process.

Jan 1, 2005

The Abra mineralized body is regarded as a significant new style of mineralization for its environment. It is a blind polymetallic deposit, located in the Bangemall Basin of Western Australia. It was discovered by Geopeko in 1981 by diamond drilling a coincident magnetic gravity target, which revealed a large low grade epithermal Fe-Ba-Pb-Ag-Cu-(AuW) deposit, hosted by chemogenic and clastic sedimentary rocks, overlain by 200-500 m of clastic sedimentary rocks, of Middle Proterozoic age. The mineralization occurs as an upper stratabound phase, and a lower vein "stringer" style phase within a pervasive chlorite alteration envelope.

Jan 1, 1987

By G M. Zhomin, A S. Arkhipin, A Kondratiev

Viscosity of multicomponent slags is one of the crucial physicochemical properties for many industrial processes and technologies. While the viscosity-temperature relationship of completely molten slags can well be described by an Arrhenian-type law, the compositional dependence of viscosity is still not fully understood, especially in compositional regions with the lack of experimental data (eg at the glass-former concentration of 90 molar per cent or higher). In the present work major compositional relationships of the activation energy of viscous flow have been revised for numerous binary and ternary slag systems on the basis of experimental data collected and stored in the viscosity database OxiVis. For example, it has been found that the activation energy relevant to the polymerisation effect in binary systems of the MO-GFO type, where MO is the modifier oxide (ie monovalent K2O, Na2O, Li2O and bivalent CaO, MgO, BaO, MnO, PbO etc) and GFO is the glass-forming oxide (SiO2 or B2O3) is not always proportional to the third power of XGFO (contrary to the Urbain formalism) and can vary significantly dependent on the slag system. Also, the activation energy of the charge compensation effect has been revised for ternary systems of the AO-MO-GFO and AO-MO type, where AO is the amphoteric oxide (Al2O3, Fe2O3 or other). A simple polynomial model has been proposed on the basis of the carried-out analysis for estimation of viscosities of multicomponent slag systems. The model has been optimised against the experimental viscosities in the selected binary, ternary, and higher-order oxide systems and has been shown reasonable agreement with the experimental data.

Aug 21, 2024

By B Vorster, T Medhurst, A Huey

Roof conditions at Oaky North Mine can be prone to stress related damage and/or time dependent degradation. The ability to identify these areas prior to mining has proved challenging using traditional methods. To help alleviate this situation, a study was initiated to investigate methods for roof characterisation using geophysical logs. This involved the use of neutron log data to provide an indirect measure of the proportion of carbonaceous/micaceous laminae present in the immediate roof strata. Detailed analysis of the shale–porosity inter-relationships arising from this analysis provided a means to estimate the proportion of laminations for a given roof interval. This paper outlines the process and how it was used to improve the current GSR modelling and hazard mapping process.

Nov 29, 2022

By A Jankovic, D David, P Payne

Although the majority of current steel production is supported by iron ore sourced from high-grade haematite deposits, the long-term growing demand for steel has led to higher raw material prices and opened the way for many new magnetite deposits to also be developed. There is a rich and long history of magnetite ore processing in Western countries, including large operations such as Cleveland Cliffs in the USA and LKAB in Sweden, as well as smaller operations like Savage River in Tasmania. The challenge for virtually all magnetite operations is to minimise operating costs, which is dominated by the cost of power required to fine grind the ore in order to achieve acceptable concentrate iron grade together with low impurity content. This remains the case today and will be even more important in the future when a carbon tax is expected to become a significant addition to the operating costs for magnetite deposits. Historically, the lowest operating cost was achieved by multistage fully autogenous grinding with integrated magnetic separation steps between the stages. The major benefit of fully autogenous grinding is the elimination of steel grinding media costs and the need to discriminate between steel and magnetite in coarse magnetic separation. The separation step between grinding stages progressively reduces the amount of material to be ground. Application of more efficient grinding technologies developed in the last 20 years, including high pressure grinding rolls (HPGR) for fine crushing and stirred milling for fine grinding, has provided opportunities to further reduce the operating costs associated with comminution. Both technologies are already implemented in some magnetite processing operations, although in limited capacity. The results of a theoretical option study for high capacity processing of a hard, fine-grained silica-rich magnetite ore is presented in this paper, with the emphasis on comminution circuit options. Several circuit options are ranked based on a net present value analysis incorporating an estimate of carbon tax added in the operating cost. The study demonstrates the significant advantages of applying more efficient autogenous grinding technologies.

Jan 1, 2009

Efficient project planning during the detailed feasibility to final engineering stages of a project requires not only the accurate prediction of the grade, tonnes and recovery, but their degree of variability as well. An understanding of the major parameters involved in the grade and tonnage estimates is essential, and the communication to those receiving the results is most important. The personnel involved in the project require more than just a global reserves classification. Quality parameters other than grade should be evaluated as carefully as the estimate itself. This paper does not present any novel ideas to overcome or enhance any of this. Rather, it takes a step back and tries to look at the global picture of requirements for proper project planning.

Jan 1, 1987

By X Dahe

SLon vertical ring and pulsating high gradient magnetic separators possess excellent mineral processing ability and have been widely applied to process oxidised iron ores. SLon centrifugal separators are applied to clean the SLon magnetic concentrate and remove quartz and other gangue minerals associated with a small portion of magnetite.This paper introduces the application of this technology in Hai Nan, Da Hong Shan and An Shan for processing oxidised iron ores.

Jul 11, 2011

By A R. McKinnon

The recently opened Hera Au-Pb-Zn-Ag mine in central New South Wales has provided an ideal opportunity to demonstrate the calculation of sulfide ore mineralogy using normative methods. Normative mineralogy applies a set of sequential rules based on the species likely to be present to assign the chemical components of a sample to their respective mineral components. The dominant sulfide mineral assemblage present at Hera is galena, iron-bearing sphalerite, chalcopyrite, pyrrhotite and pyrite. A normative technique for estimating the relative abundance of each of these species from drill hole, grade control and metallurgical assay data sets has been developed. This includes a process for deriving a gangue iron value and differentiating pyrrhotite from pyrite using sulfur/iron ratios. A calculated total sulfide volume value has been utilised at the mine to improve interpretation of lode boundaries. Normative drill hole values have also been used for domaining within the orebody, with large scale mineralogical trends evident. Dry bulk density (BD) values calculated using a normative species-weighted method show good correlation with measured BD values (R2 = 0.895) and are a significant improvement on the Pb+Zn+Cu regression method (R2 = 0.646) previously used. Application of these calculations to identify errors in assay databases is demonstrated, with specific reference to the data set for the nearby Nymagee copper deposit. Validation of block model grades is also explored and a method to improve resource estimates using direct normative mineral interpolation is proposed. The integration of the normative data into the production and metallurgical data sets at Hera is described and the relationship of the normative minerals to other economic elements such as gold and silver is discussed.CITATION:McKinnon, A R, 2017. Application of normative ore mineralogy to geological and metallurgical data sets at the Hera Au-Pb-Zn-Ag mine, New South Wales, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 63–74 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By C Parihar, R Garg, A Bhandari, S Bhandari

Blasting can impact the efficiency of entire downstream mining operation. Individual technology solutions for blasting have been available in the industry for many years but all of them only cater for certain aspects of blasting. Many of them are based on individual research and/or experiences. Some of the available software solutions are not suitable to be used in the field as that they need advanced skills or tools. Also, most do not take technology advancements like mobility, advanced data analytics, web solutions and integration into consideration. Hence, no technology platform is currently present in the industry that addresses all potential needs a blaster may need in an integrated manner.This paper presents an integrated solution that takes care of all aspects of blasting – design blasts according to mine plan; collect data after drilling has been carried out (as there is often difference in designed and actual drilled hole locations in the field); predict blast results in terms of fragmentation, flyrock, ground and air vibrations, wave front reinforcement and flyrock distance; and after assessment, allows changes in charging, delay timing and sequence. The technology solution is a secure, cloud-hosted, web-based software-as-a-service solution that can be accessed from anywhere. Also it has a mobile app, which is available for both Android and iPhone/iPad. The mobile app is also integrated with the web-based solution using application programming interface calls to the central data repository.Case studies for two limestone mines are presented where this solution is being used in its initial format. This software platform enabled analysis of the outcome from a previous blast pattern and then subsequently allowed optimisation of blasting operations based on historical data. Uses of this platform have resulted in improved key performance indicators in these two limestone mines. The mobile app as part of this platform enables extensive field blast data capture and analysis and also various predictions before a blast. Data collected include blast parameters, individual hole charging, initiation pattern, videos, photographs and vibration records for analysis/reporting. The key features of the solution are a blast designer, a detailed blast data collection/analysis and a series of environmental predictors. These predictors give blast results in terms of fragmentation, flyrock, ground and air vibrations and wave front reinforcement and take remedial steps before blasting to optimise and control adverse environmental impact. Many features, such as fragmentation predictor and mobility solution, are completely unique features that are not available elsewhere in such a field personnel-friendly manner.CITATION:Bhandari, S, Parihar, C, Garg, R and Bhandari, A, 2015. An integrated technology solution for optimised and environmentally-controlled blasts, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By E Jak, J Chen, B Hogg, S Nikolic, S Nicol

The quantity of post-consumer ‘waste’ materials generated each year is rapidly increasing. These materials can contain significant quantities of critical metals and present an environmental challenge if landfilled. The ISACYCLE™ technology is a proven solution for the processing of these materials. In the ISACYCLE™ furnace, the post-consumer materials are processed to recover energy along with any contained critical metals, in the form of a base metal alloy or matte. In addition, a clean aggregate (slag) is generated, which has the potential to be used for a range of applications in the construction industry. This slag is commonly based on a fayalite slag but is modified to manage the complex feed. This paper will review the fayalite slag system and the theoretical modifications required for treating urban wastes. Slags from an ISACYCLE™ furnace processing urban wastes have been sampled and characterised. The chemistry of these samples will be reviewed and compared to the expected theoretical modifications required.

Jun 19, 2024

By T J. Napier-Munn, T Perkins

The JK Drop Weight test was developed at the Julius Kruttschnitt Mineral Research Centre (JKMRC) in the early 1990s as a means of characterising ore for the purposes of AG/SAG mill and crusher modelling. It has since been used extensively worldwide in the minerals industry as a key ore characterisation test which produces parameters which are used in comminution circuit design and optimisation. The test generates three parameters which are used in the AG/SAG mill model of the JKSimMet software. The resistance of the ore to high energy (impact) breakage is quantified with the A and b parameters. The oreÆs resistance to low energy (abrasion) breakage is measured using the ta parameter. The accuracy and precision of the results of the JK drop weight test are of great importance given that the parameters are key inputs in the design of such capital intensive items as SAG mills. Plant optimisation exercises also rely on the accuracy of the parameters to assist with improving the performance of an existing circuit. A thorough analysis of the accuracy and precision of the parameters generated by the JK drop weight test has now been undertaken by JKTech Pty Ltd (JKTech). An experimental program was designed using statistical methods to plan a hierarchical set of 24 drop weight tests on homogeneous material. Each stage of the test was identified and incorporated into the experimental design so that the contribution to the overall error of each stage could be quantified, including the effect of operator. The data were analysed by nested analysis of variance. An overall analysis of the A, b and ta parameters generated from the test program has now quantified the variance of these parameters more thoroughly than ever before. Using the results for the impact parameters, an analysis has been carried out to investigate the effect of these variances on final SAG mill comminution circuit design. The results will also be used to refine the comparative testing procedures currently in use by licensees worldwide.

Jan 1, 2008

To finalise the arrangement and details of the headframe to be erected over the new No. 3 Shaft, the haulage and winding equipment requirements were first determined, then tentative designs were prepared to cover the needs of general shaft servicing work for men and materials, mullock and ore handling, and the probable requirements of a breaker station to be built adjacent to the headframe, which would provide for the crushing of the run-of-mine ore down to a size which would be suitable for feeding on to the concentrating mill.

Jan 1, 1957

By C Laming, S Staude, D Hammond, S Sheppard, J Griffith, S Stanfield, S Marriott

Long Operations is located on the eastern slope of the Kambalda Dome in Western Australia. Kambalda hosts nickel deposits that are modelled to have formed from an exsolving sulfide melt from a parental komatiite melt. The nickel deposit model predicts a stratigraphical relationship where massive Fe-Ni-Cu-sulfides are deposited in troughs at the base of komatiite channels. The basal contact of the sulfides is generally tholeiitic basalt. The Kambalda geological sequence form a dome structure with a granodioritic core and have undergone tectonic and metamorphic overprinting, resulting in the formation of upper greenschist to lower amphibolite-facies units.On the basalt-ultramafic contact, within the Long Operations, there are two separate channels hosting seven different orebodies. The Moran orebody is the most undisturbed orebody at Long Operations, with many primary magmatic textures preserved, making it ideal for studies to improve the existing nickel sulfide formation model. Detailed exploration and production infill drilling and systematic sampling indicates consistent nickel tenor variations over the entire Moran orebody. This was also observed in other deposits in Western Australia and was explained as metamorphic variations. Similar variations are observed with some trace elements that cannot be explained by metamorphic overprint but with gravitational segregation in the liquid sulfide. Other more complex trace element patterns (eg Cr) require additional explanations and are partly originated from incorporation of underlain basalt and sediment and partly from gravitational segregation.From a mining perspective, the Moran orebody can be used as an example of modern high-speed mining, but at the same time preserving samples for the future and allowing knowledge from the geological context and geochemical signatures to improve future exploration.CITATION:Staude, S, Marriott, S, Griffith, J, Laming, C, Hammond, D, Stanfield, S and Sheppard, S, 2014. Improvement of existing ore-forming models due to systematic sampling during mining – an example from Kambalda, Western Australia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 341–348 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By Reichman J. P

Extensive use is made of a small scale computer (IBM 1130), in the calculations of ore reserves for Western Mining Corporation's nickel mine at Kambalda, W.A. All surface drilling data such as assays, density and location information, are stored on disk files at the Company's Technical Computing Centre at Perth, W.A. The computer is used to search through the data, select significant ore intersections, calculate the area of influence of each intersection and perform the necessary calculations to arrive at an estimate of the ore reserve. Comparing the computer-assisted ore reserve calculation with an entirely manual operation, it is estimated that a saving of 40 percent in time is achieved together with

Jan 1, 1973

By I Ritchie, A Johnston, D Yataco

Marcobre SAC (Marcobre) is developing the Mina Justa copper mine project, located in the Ica region of Peru. The Mina Justa IOCG orebody comprises of a sulfide mass overlain by an oxide cap with a sharp transitional zone between the sulfide and oxide masses. The primary target metal is copper, but there are minor amounts of gold and silver. The oxide will be treated by HPGR, crushing and vat leaching, whereas the sulfide will be treated by HPGR, milling and froth flotation. The processing selections are due to some unusual ore characteristics which have required relatively unconventional solutions.Vat leaching was chosen over heap leaching and other processes after detailed trade-off studies found it to be the most attractive, primarily due to the high acid consumption of the ore. The sulfide flotation produces a wide range of concentrate grades due to the complex nature of the mineralogy. The selection of HPGR circuits for both the oxide and sulfide ore is due to the extremely hard and competent nature of the deposit. These factors and others have contributed to a unique process selection for this resource.The selection process for the oxide and sulfide ores, and an overview of the technology, equipment selection and geometallurgy, will be discussed.CITATION:Johnston, A, Ritchie, I and Yataco, D, 2017. Process development for the Mina Justa project, in Proceedings MetPlant 2017, pp 207–217 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By R M. Krek

The haulage system used to convey ore from an underground mine to a surface stockpile at the mine process plant is a vital component of the mine’s overall infrastructure and economic viability. The system selected has a significant impact on the set-up of the mine and the access to the underground mine. In turn, the set-up of the mine and the access to the underground mine have a significant impact on the system.A number of haulage technologies are available to transfer the ore from the underground workings to the surface stockpile, including hoists, conveyors, rail and trucks.This paper focuses on the shaft hoisting and inclined conveyor haulage technologies. These technologies have been used consistently to deliver ore from at depth and/or at high tonnage. Previous reviews of the appropriate vertical haulage systems have nominally been restricted to the respective systems only, with no consideration for any other scope or issues that may affect the selection. The selection of the appropriate vertical haulage system, whether shaft hoisting or inclined conveying, needs to consider numerous key factors.CITATION:Krek, R M and Northcote, A E A, 2014. A holistic viewpoint for selecting the vertical haulage system – shafts and conveyors, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By W N. Qin, B Zhang, W Z. Huang, X S Mo

Mengzi Mining and Metallurgy Co, Ltd (MMMC) polymetallic ore contains recoverable amounts of tin, lead, zinc, pyrite and other valuable minerals. With the change in orebody, the run-of-mine (ROM) ore changed from lead zinc rich ore to tin rich ore, where the current ROM ore contains 0.45–1.25 per cent tin, 20–25 per cent sulfur, and 0.20–0.35 per cent copper. The previous processing flow sheet was designed to recover lead zinc rich ore and it is clearly not suitable for recovery of the current tin rich ore, where the tin was already overground and tin recovery was only 50.19 per cent. The Mengzi Mining Company has recently modified the concentrator circuit by incorporating rod mill and high efficient Derrick fine screen. As a result of the improved classification efficiency, the overgrinding of the tin ore was minimised and the recovery of tin was improved by 20.71 per cent, ie from 50.19–70.90 per cent. An additional $10 M revenue per annum can be achieved as a result of the modification.CITATION:Qin, W N, Huang, W Z, Mo, X S, Zhang, B and Wheeler, J, 2014. Application of high efficient fine screen to improve the recovery of tin concentrate, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 487–492 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By J Li

Cannington Mine has been developing through paste backfilled stopes since the year 2000. These paste drives have been used as either production drill accesses or long-term bypasses. Prior to this study, the ground support requirements for each paste development cut were: an initial 50 mm layer of fibrecrete, weld mesh bolted with 2.4 m split sets, followed by a second coat of 50 mm fibrecrete. Both layers of fibrecrete and the layer of mesh were to be installed before the next cut could be bored and fired. This support regime proved successful at Cannington, however, the total cycle time for each cut was lengthy due to the installation and curing times associated with each layer of surface support. In an effort to reduce the cycle time a study was carried out, with the aid of RocScience’s Phase2 numerical modelling software. The modelling reviewed all of the parameters controlling the stability of a newly excavated development cut. The parameters studied included the early strength of fibrecrete, the ground support load capacity, and the strength of the paste fill masses which varies depending on the cement content. As a result of the study, the ground support standard was revised. The revision has significantly decreased the cycle time as well as fibrecrete consumption, all the while maintaining the safety of personnel and equipment.

Mar 21, 2011

By C Itotoh, K O’Halloran, L Karlson

Global methods used to explore for minerals have progressed relatively slowly since the development of the first diamond core drill in 1863. Since then, key developments such as wireline geophysics (1920s), the tricone drill bit (1930s) and aeromagnetic surveys (1940s) all occurred in response to global events. In this project, BHP’s WAIO Geoscience operations team hypothesise that a global movement towards a greener future as well as an increasing intolerance for safety events will drive another step change in exploration methods. We have leveraged our relationships with exploration contractor partners and industry leaders to develop a realistic vision for 2033 and beyond, where drill rigs, earthworks and geophysical units are operated and maintained remotely; emissions of dust and waste are eliminated; hazardous energy sources are controlled; procurement is based on sustainability rather than cost and carbon emissions are tracked with the same rigour as production metrics. We have combined these visions into a series of graphical illustrations with the aim of inspiring ourselves, our vendors and our peers to collaborate further on producing a step change in our industry.

Sep 18, 2023