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By M T Roche

The Cannington deposit is one of the largest accumulations of silver-lead known. Located 135 km southeast of Cloncurry in North West Queensland (Figure 1), Australia, the deposit is currently in the feasibility stage of its development. The deposit is named after the nearby Cannington Pastoral Property which runs some 25 000 sheep on 'downs' country. The investigations of the Cannington deposit are carried out under the authority of Mineral Development Licences 139 and 144 and Exploration Permit for Minerals 6788, Answer Downs. Exploration for Broken Hill Type (BHT) silver-lead-zinc deposits in the Mt Isa region has been undertaken by The Broken Hill Proprietary Company Limited's Minerals Division (BHPM) since the early 1980s following in-house research which showed that the Eastern Succession of the Mt Isa Block exhibits characteristics which were favourable for hosting BHT

Jan 1, 1994

This paper describes techniques that have been used at RixÆs Creek Colliery to control blast vibration from throwblasts that face a residential area 4 km in front of the face. The paper describes blast design, face control including laser profiling, selective loading of blastholes after borehole camera surveys, and techniques used to assess the effect of burden variation, the cumulative effect of drilling and delay sequence, and the effects of meteorology.

Jan 1, 2001

By Z Lubosik, S Prusek, M Plonka, B Syrek

"The most commonly used method of thick coal seam extraction in Polish deep mines is multislice longwall (MSL). In MSL stability of goaf in the roof as a result of previous extraction in upper slice is a major geotechnical consideration that must be managed.This paper outlines the results of a wide range of investigations carried out in three longwalls that were in operation in a multislice system using caving with additional fly ash goaf stowing. The longwalls were operated by Katowicki Holding Weglowy SA (KHWSA) in the Upper Silesian Coal Basin of Poland.Examinations were completed on the properties of goaf at the roof of longwalls ie measurements of strength parameters of the goaf material by means of a borehole hydraulic penetrometer, determination of the goaf condition by means of a borehole endoscope and laboratory testing of the caved rock. The results of underground examinations of the loading on yielding arches in the gate roads associated with these longwalls and measurements of vertical and horizontal convergence are also presented.CITATION:Prusek, S, Lubosik, Z, Plonka, M and Syrek, B, 2014. Multislice longwalling for thick seam extraction – properties of goaf in the roof and gate roads behaviour, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 359–366 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

By Revy T

A testwork program aimed to improve the assaying of underground face samples established that for an Accelerated Cyanidation Extraction using the LeachWELLTM 60X catalyst, followed by an Aqua Regia finish (to quantify non-cyanide-extractable gold): ò Assay results (including the aqua regia finish) from a full set of samples from one underground face can be returned within four hours. ò The reagent dose to make the method simple and 'bullet-proof' is 8 gm LeachWELLTM 60X and 20 gm NaCN per 200 gm sample (30 per cent solids). Pulverising is to 90 per cent passing 75 micron (compared to the standard of 90 per cent passing 150 micron), and cyanidation is completed within one hour - however both might be further optimised. ò The LeachWELLTM/Aqua Regia results demonstrate that Fire Assays suffer from a significant nugget effect which makes the Fire Assay data relatively unreliable. ò Original costs, specific to Bannockburn (viz including an Aqua Regia finish), handling approximately 20 000 to 25 000 per annum is estimated to be $5.40, ie about one-third less than fire assaying. Optimising is further reducing these costs. It is estimated that the LeachWELLT"'/Aqua Regia assay procedure has reduced the probable error limits of any given assay of this ore from the range 0.74x to 1.36x for Fire Assay, to an appreciably smaller range of 0.90x to 1.11x. Thus for a cut-off grade of 1.60 g Au/t, samples with Fire Assays ranging up to 2.18 g Au/t have 25 per cent chance of being below cut-off, while samples with Fire Assays as low as 1.18 g Au/t have an equal chance of actually exceeding cut-off grade. This 1 g Au/t range in uncertainty is generally unacceptable for many practicalgrade/tonnage relationships. By contrast, using LeachWELLTM + Aqua Regia assays, the estimated corresponding limits are 1.44 g Au/t and 1.78 g Auk respectively - a far more tolerable 0.34 g Au/t range of uncertainty. Subsequent data has demonstrated that sufficient accuracy for grade control is achieved by Accelerated Cyanidation alone, further halving the cost of assays.

Jan 1, 1994

By P Willems, J B. Crow, R Dale

Open pit mining commenced at Lihir Island in 1997 and is undertaken using a conventional drill, blast, load, haul methodology. Unique challenges at the operation include an active geothermal system, a well-developed advanced argillic blanket in the upper portions of the orebody and high rainfall. Grade control is effective utilising routine blast cone sampling. While this provides ‘just in time’ grade information for mill blending, there are opportunities to improve scheduling of mill feed, based on material classification of clay types and sulfur grades. The nature of the clay can impact on the handling properties while the sulfur grade is an important guide for autoclave blending, required for refractory gold. Drilling below the pit floor introduces hazards from the identified geothermal field. A trial Reverse Circulation (RC) program was implemented with the aim of defining four benches below the active mining bench. A comprehensive risk analysis, including the geothermal environment, was undertaken to design a drill collaring procedure with pressure diversion equipment. Operator exposure was minimised through ‘nil on foot’ principles with the driller located in an onboard cab, utilising remote rod handling. Sampling personnel operate in an elevated platform with access to protective covering. Samples from blastholes and the RC holes are processed at two site laboratories. One provides conventional Au fire assays with additional Infrared Combustion (Leco style) S analysis. The second laboratory collects material classification details from portable XRF (pXRF), near infra-red spectrometry (ASD) and Hardness Indicator Testing (HIT). An existing workflow was updated by the site to deal with the additional samples and ensure production ‘turn around times’ were retained for short-term planning. This required some changes to drying temperatures, compositing and screen sizing for the material classification. All results from the two laboratories are loaded into a centralised acQuire database for estimation into a single block model that informs the 13 week medium term planning (MTP) schedule. This paper describes some of the logistical issues faced when drilling in a geothermal area. It also discusses the selection and commissioning Quality Assurance of the sampling equipment and drill rig. Integration of the resulting assay data with existing resource models is also explained.

Mar 22, 2022

The Newcrest Mining Limited Telfer Gold Mine consists of an underground sublevel cave (SLC) operation located 734 m directly below active open pit operations. Open pit and underground current production rates are 50 million and 5.7 million tonnes per anum (Mt/a) respectively. The SLC was initiated in late 2006 with breakthrough planned to occur on the 5484 bench of the west wall in late 2009. Risk to the south ramp was identified during this time, resulting in the construction of the north ramp. The SLC was continually tracked from initiation with a suite of monitoring systems and managed with a Major Hazard Management Plan (MHMP) and associated Trigger Action and Response Plans (TARP). At breakthrough the eastern limb of the cave was located within a 70 m horizontal distance from the south ramp. The south ramp was closed in October 2009 due to significant slope deformation, extensive cracking in the berms and batters between the ramp and breakthrough bench and a major failure 250 m to the north of the cave breakthrough. Wall response was first identified from slope deformation measurements taken by the wall monitoring radar in May 2009, at which point the SLC was 160 m from breakthrough. The impact of the SLC on the slope is a unique case with the monitoring systems in place able to provide data on the slope reaction to the SLC progression. This paper will discuss the management of the south ramp such as the early interpretation of risk associated with cave breakthrough, monitoring systems implemented to track the cave progression and wall deformation, data integration and interpretation and risk management. Following the closure of the south ramp further instrumentation programs and risk assessments were conducted to determine the risk of re-opening this haulage route. The outcomes of this program will also be presented.

Nov 25, 2010

By J J. Laas, A J. S Spearing

Considering the capital outlay, running costs and inherent difficulties of backfilling operations at depth the benefits need to be clearly established, quantified and then exploited. Expansion of Vaal Reefs Exploration and Mining Company towards even deeper, highly faulted ground, and the process of establishing codes of practice for the management of rockfalls and rockbursts, required that a sound support strategy be formulated. This paper describes the derivation of an overall backfilling strategy on Vaal Reefs. Use was made of experience gained over some 12 years with backfilling. Numerical modelling was used to estimate potential benefits of backfilling the deepest mining areas still to be extracted. In exploiting a probably unique opportunity, two contiguous mining areas bounded by the same major geological structures, were compared. One was extensively backfilled and the other not at all. Shaft sinking through a backfilled stope added another dimension to the database.

Jan 1, 1998

By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

The comparison of belt drives with other types of power transmission involves the consideration of many factors before a final choice is made. Where other forms of power transmission might also be suitable, the selection of the correct type of belt has first to be made, in order to obtain a true comparison. The paper first deals with the types of belting available, followed by a description of most other forms of transmission equipment. An example is then given of the selection of suitable belts, which are then compared with other types of transmission. Comparative costs are also given. Reference charts provided show drives found suitable in general practice...

Jan 1, 1964

By B Patterson, Y Lanwin

Over the last decade the adoption of autonomous technology has proven its potential to fundamentally alter the mining industry, offering significant improvements in safety and productivity. Automation levels are now increasing exponentially across all parts of the supply chain from drilling, haulage, processing, rail and shipping to the maintenance of the above. However, the management of human error risk is also becoming increasingly complex as the disconnect between the people who operate and interact with mining equipment and those that design the autonomous systems grows in terms of skill and expertise. Furthermore, as comfort levels with automation increases amongst operators, complacency is increasing as the initial functional safety benefits have been realised. This paper introduces an innovative concept that unites two distinct fields, functional safety and behavioural economics, to address the complex issue of human error risk in autonomous mining operations. Functional safety, a well-established field in engineering involves identifying potential hazards, assessing risks and designing systems in a way that minimises the chances of accidents and limits their consequences. Meanwhile, behavioural economics takes a data centric approach to analysing the psychological aspects of human decision-making, acknowledging and seeking to understand the errors that can originate from cognitive biases and heuristics. This paper seeks to bridge these domains by emphasising that human error in autonomous mining is not solely a technical issue but is deeply influenced by human behaviour and decision-making processes. By incorporating insights from behavioural economics, we can better predict, prevent and manage human errors in the mining sector. By applying principles from both disciplines to a recent incident example we will explore how cognitive biases can impact peoples’ interactions with autonomous mining equipment. This interdisciplinary approach will not only enhance the design and implementation of functional safety measures in mining but also lead to the development of people centric solutions that consider the inherent fallibility of people. We will explore how human centred design can help bridge the gap between these two domains and apply systems thinking for a universal approach. Through an indepth case study analysis and empirical data, our research aims to provide actionable insights and practical recommendations for mining industry professionals, regulators and stakeholders involved in the safe integration of autonomous systems.

Apr 16, 2024

By Coxhead B. A, Brandt B. A

The geological exploration and evaluation of coal reserves involves the appraisal of very large amounts of data. Computers afford an ideal means of handling and manipulating the data, thereby avoiding the laborious and expensive method of manually compiling the logs in full descriptive language. The Minad system of computer storage and retrieval of geological and analytical data is particularly suited to the description of cores and cuttings from exploration drill-holes. The encoded data is arranged in a 120-column computer output sheet format; descriptive geological information in a 54-column geolog and analytical information in a 64-column assaylog. The acquired data is quantitative, uniform and relatively complete and can be selectively retrieved for processing by a wide range of specialized computer programs developed for the coal mining industry. Visual retrieval of data for manual processing is facilitated by the use of simple codes and logical word abbreviations.

Jan 1, 1977

By J Jackson

The term geometallurgy (or geometallurgical) first appeared in the literature some 40 years ago and has a wide range of definitions and perspectives which increases the barriers of communication between practitioners and across functional groups and management levels within organisations. However the consistent theme running through the diversity of definitions and perspectives is the requirement for close collaboration between the relevant disciplines. This concept of geometallurgy arguably goes back to the earliest days of the exploitation of mineral deposits, through the mid-1500s to the beginning of the 20th century.This holistic and integrated view was diminished during the 20th century due to a number of factors which included the commencement and continuing upward trend of large-scale mining and the expansion in production, the rise of scientific and classical management theories and methodologies, increase in specialisation and the development of traditional project planning. The re-emergence of geometallurgy in the late 20th century required the relevant functional units and disciplines to collaborate as a team. This necessitates a common understanding that the geometallurgical program’s goals must be obtained, which requires clear and consistent communication, particularly with the modern trend of virtual teams.A multi-dimensional construct is proposed to assist in providing a consistent approach in the communication of the context and purpose of both general and specific geometallurgical programs, thus simplifying communication. This geometallurgical construct consists of the dimensions of process span, response knowledge, variability knowledge, spatial knowledge, application and project phase in relation to extraction process(es) applied to geological materials from a mineral deposit. These dimensions are then linked to the phase of mineral project development in which the geometallurgical program is being applied, which ranges from advanced exploration through to operational execution. This paper outlines the multi-dimensional construct with examples of how the context, purpose and scope of geometallurgical programs can be clearly delineated and communicated.

Sep 5, 2011

By S Maritsa, D Simbi, E K. Chiwandika, S M. Masuka

The steel industry is facing challenges on a global scale that include depletion of resources, huge energy consumption, and the emission of CO2. The demand for iron products is increasing due to the increased infrastructural development. Zimbabwe produced cast iron from scrap metals. However, there is currently a shortage of scrap, and yet Zimbabwe is rich in limonite ores that are currently being underutilised. The possibility of using limonite ore as a sustainable feed for pig iron production was investigated by preparing some limonite ore carbon composite pellets. The results showed that the addition of coal to the limonite ore and calcium carbonate mix to form the composite pellets resulted in a decrease in the drop number as well as the dry compressive strength of the composite pellets. This research aims to improve the physical properties of the green pellets by the careful addition of hydroxyethyl cellulose as a binder that was found to improve the physical properties of the green pellet. This is important for materials handling during the production process of the composite pellets. Results showed that the drop number was substantially improved by the addition of 0.4 wt per cent hydroxyethyl cellulose while the dry compression strength improved from 2.5 kg/pelIet to around 23 kg/pellet irrespective of the amount of binder added. The binder improved the physical strength of the iron-carbon composite pellets enough to allow for large-scale production of the pellets that can be an alternative and sustainable feed for cast iron production. However more results on the indurated compression strength and other properties such as the reduction degradation index, swelling index, and the reducibility test are required.

Jun 19, 2024

By Z W. Orndorff

Excavation through sulfidic geologic materials during construction activities has resulted in acid rock drainage (ARD) related problems at numerous (>40) locations across all five geologic regions of Virginia, USA. Potential acidities ranging from >100 to develop a statewide sulfidic materials risk map; document ARD impacts to soil and water quality and engineered structures; and develop methods to assess site-specific risk potentials within a given highway corridor. A statewide sulfidic materials GIS risk map was developed based upon the state digital geology map which assigned four levels of relative risk to all mapped strata based upon predicted lime requirements and probabilities of encountering highly reactive materials. Non-highway construction activities have also routinely disturbed sulfidic materials, and a recent airport project in northern Virginia resulted in over 150 ha of extremely acidic (pH 45 mg/L) run-off from this site heavily damaged a receiving stream, partially due to the fact that it dissolved the galvanised steel water control structures in stormwater detention basins, leading to direct discharge of run-off and sulfidic sediments. The airport area was treated and revegetated in 2002 with a combination of lime-stabilised biosolids, straw mulch, and acid-tolerant grasses. Water quality in a receiving second-order stream quickly responded to the treatment, but some release of N was also noted as a secondary effect. Collectively, these results point out the importance of accurately assessing the potential for excavation of sulfidic materials in construction environments, and the necessity of developing toxic materials handling strategies similar to those employed in mining environments.

Jan 1, 2003

By Bigdy D. N

The paper describes a system for providing mine management with a continuous indication of the effectivness of longwall coalface powered supports in controlling roof-to-floor convergence. The system comprises on-face instrumentation monitoring convergence and support leg circuit pressures, a means of transmitting the output of that instrumentation to the surface for collection, and software which presents both a condensed analysis for rapid review of the current state, and extended analyses from which remedial action can be recommended if a problem is identified. The results of a field trial are presented showing that meaningful results can be obtained.

Jan 1, 1988

By G V. R Goodman, G J. Chekan, J M. Listak

The extraction and transport of coal from underground coal mines can result in significant liberation of coal and/or silica dust into the mine atmosphere. Mine operators have long used ventilating air as a primary means of diluting generated dust, removing dust from the working faces and preventing dust from reaching the minersÆ working environment. As production levels have increased, mine operators continue to be challenged in maintaining dust concentrations below compliance levels. The need for maximising the effectiveness of available ventilating air in conjunction with other effective controls, such as water sprays and dust collectors, continues to be critical to the long-term health of mine workers. The National Institute for Occupational Safety and Health (NIOSH) has conducted full-scale laboratory and mine-site research to evaluate improved application of dust controls for both longwall and continuous mining methods. A summary of recent research results and recommended practices will be provided.

Jan 1, 2005

Low-grade, porphyry copper type mineralization at the Moonmera prospect is related to the intrusion of a granodiorite porphyry mass into the Upper Permian "Gracemere granodiorite". Significant copper mineraliza- tion appears to be associated with the alteration assemblage quartz-sericite- kaolinite. The ore shell is surrounded by a zone where montmorillonite and kaolinite are in greater abundance and this assemblage is over- lapped, mainly at depth, by potassium feldspar alteration. Secondary biotite is abundant throughout the mineralized zone. Preliminary sulphur isotope results on the sulphide mineralization are compatible with a magmatic origin for the sulphur.

Jan 1, 1974

By Jaques A. L, Heinrich C. A

Mt Todd lies towards the south end of the Pine Creek Geosyncline, sandwiched between the Cullen Batholith and the Edith Falls Basin, in an area of regionally metamorphosed sandstones, siltstones and shales. The Batman deposit, some 3 km west of Mt Todd is a sheeted quartz vein system hosted within greywackes of the Palaeoproterozoic Burrell Creek Formation (Finniss River Group). The gold-bearing quartz veins, trending 010¦-020¦ and dipping 60¦-70¦E, are commonly 0.5 to 5 cm wide and occur at intervals which are from 10 cm to 1 m apart. Gold tends to be restricted to the quartz veinlets and immediately adjacent country rock. Grade Control utilises two 4 m 'collar' samples which are collected from each 8 m production blasthole. The irregular distribution of the quartz veins and erratic gold mineralisation has resulted in a disseminated 'salt and pepper' type of gold occurrence, with only a poorly defined footwall. Delineation of ore and waste blocks for mining uses an approach which combines the smoothing effect of kriging with a pragmatic view of the raw data. Large ore blocks with simple geometry help to minimise mining dilution, reduce block variance and give good reconciliations to interpreted ore tonnes and grade. Daily mine face advance is reported against truck counts and provides continual comparison with budgeted production. All data processing uses Gemcom software, together with Lotus spreadsheets.

Jan 1, 1994

By Armstrong M

The Clermont Coal Mine will export steaming coal from the Wolfang Basin in Central Queensland, Australia. It is expected to be developed in the mid-1990s.The majority of the reserves lie in the 30 m thick Wolfang Seam. Overburden depth varies from 80 m at the subcrop line to 190 m in the centre of the basin.

Jan 1, 1992

By P Gleeson, J Coombes, P Suresh, T McLennan

The last 20 years have seen a dramatic rise in the use of 3D visualisation and modelling for geological data, but there has been relatively little effort to do the same for the variogram models that underpin the standard estimation algorithms used by the mining industry.For kriging, one of the most used geostatistical estimation methods, specifying a variogram model is a critical part of the modelling process. Experimental variography is the primary method for approximating the theoretical variogram function from the available sample data, and then determining an appropriate variogram model from the approximations.The traditional tools used for experimental variography are limited to looking at subsets of the data and are often presented without reference to geographic space and geology. It can be difficult to know what input data is being used for a particular experimental variogram, and whether there is enough support in the experimental variograms to propose an appropriate model.To overcome these limitations, an innovative approach called situational variography has been proposed that visualises variograms in 3D alongside contextual geological and geometric data. Presenting variograms in this manner aids understanding of how the spatial variance relates to the underlying data.A 3D extension of the 2D radial variogram maps will be investigated which allows for dynamic exploration of the full experimental variogram cloud. These 3D experimental variograms are much easier to visualise situationally.A workflow for situational variography will be outlined and the advantages of the situational approach will be illustrated using a porphyry copper deposit.CITATION:Gleeson, P, McLennan, T, Suresh, P and Coombes, J, 2017. Situational 3D variography – determining the variogram in the context of geology, in Proceedings Tenth International Mining Geology Conference 2017, pp 191–198 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017