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By M J. Nugus, F Clark, E J. Hill, J T. Carswell, J S. Cleverley, N H. S Oliver

High-nugget gold orebodies are difficult to model in 3D because samples from diamond drill core are generally too small to provide reliable estimates of the gold content of the larger body of rock, and therefore interpolation of gold assay values between drill holes is also unreliable. As a result, gold resources are generally underestimated in areas of high nugget. In practice, proxies for gold mineralisation, such as presence of alteration, specific structures or high vein density, have been used by geologists to predict rocks which are favourable for mineralisation. However, there has been no automated method for combining the predictive capabilities of several proxies, except by human judgement.We have been developing a method to combine several different types of geological features or geochemical analyses into a single measure using conditional probability. Conditional probability provides a meaningful numerical measure for the favourability of rocks for containing high-grade gold mineralisation. This measure can be interpolated in the exploration space, providing a sound basis for a 3D model of the orebody. We have developed this technique using data from the Sunrise Dam Gold Mine, which is a high-nugget orebody hosted in a structurally complex Archaean greenstone belt and which has historically proved to be a very challenging orebody to model.CITATION:Hill, E J, Nugus, M J, Clark, F, Oliver, N H S, Cleverley, J S and Carswell, J T, 2013. Predictive three-dimensional modelling of nuggety gold orebodies, Sunrise Dam, Western Australia, in Proceedings World Gold 2013 , pp 463-468 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By E Nye and T Schroeter, B Muir, M Kitson, M Gonzalez, D Mares

The single track North Strathfield Rail Underpass (NSRU) consists of a dive structure either end of a 148 m long driven tunnel skewed under three live railway tracks. The tunnel is 8 m high, 9 m wide, with a horseshoe profile, excavated by full face using a road header. Ground cover varied between 2.5 m to 3.5 m. Settlements were 5 mm to 15 mm (the latter due to a dyke). A one pass synthetic fibre reinforced shotcrete lining was installed (no lattice girders or steel sets were used). A system of automated robotic total stations was used to provide real time monitoring of the rail track and associated ground formation. No disruption to train services occurred.CITATION:Gonzalez, M, Kitson, M, Mares, D, Muir, B, Nye, E and Schroeter, T, 2014. The North Strathfield Rail Underpass – driven tunnel design and construction, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 369–374 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Barden, G Lane, B Quilliam

NQ Minerals PLC, through Hellyer Gold Mines Pty Ltd, plans to reprocess the contents of the Hellyer tailings dam to produce lead/silver concentrate, zinc concentrate and pyrite concentrate (containing Au and Ag). This paper discusses the project development, mineralogy, metallurgy and chemistry of processing Hellyer tailings and the associated environmental benefits. The Hellyer and Fossey orebodies were volcanic hosted polymetallic massive sulphide deposits located within the Mount Read volcanic arc of western Tasmania. Mineralisation was hosted in massive sulphide (pyrite) and comprised predominantly of sphalerite, with lesser galena, chalcopyrite and arsenopyrite. The Hellyer orebody was mineralogically complex (fine grained) and was treated through differential flotation with initially modest recoveries. Fossey ore processing characteristics were similar to those of Que River ore and simpler than Hellyer but treatment still resulted in significant grades in flotation tailings. CITATION: Lane, G, Barden, M and Quilliam, B, 2018. Hellyer tailings – complex mineralogy but higher grade than many ore bodies, in Proceedings Complex Orebodies Conference 2018, pp 35–38 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

This paper describes a detailed geostatistical study of producing copper orebodies at Mount Isa Mines Limited in Queensland, Australia. As a result of this work, kriging has been adopted for grade estimation for final stope design at Isa Mine. Extensive variogram and back analysis studies indicate that one relative variogram model can be used to give optimal kriged grade estimates from production sampling throughout the 100 million tonne copper orebody complex. The kriging method replaces a computer technique used at [sa Mine based on inverse distance weighting using parameters chosen from experience.Comparative stope designs based on 10 million tonnes of ore indicate a 16% increase in minable ore tonnage at a grade well above the cut-off, as a result of the geostatistical work.Although this paper is written as a practical description with simple explanations of geostatistical concepts, the theory and use of relative variograms has been expanded. A possible link is suggested between relative variograms and first order kinetics of natural mineral concentration processes.

Jan 1, 1982

By S Zheng, Y Zhang, Z Wen, S Ma

Red mud (RM) is a solid waste product generated during alumina refinery process, and is usually stored in SFs (SFs) because it canÆt be disposed of easily. In this paper, environment degradation caused by RM-SFs was systematically assessed by the method of single factor pollution index based on the analysis data of water, soil and atmosphere sampled around one newly-built and one decommissioned RM-SFs, which are managed by an alumina production company in China. The results revealed that the ambient environment around RM-SFs is seriously polluted by alkali and mercury (Hg). The pH value of RM leachate, surrounding surface water and groundwater are all higher than the limit of water quality standards in China. And as a possible result of overflowing of high alkaline leachate, soil pH value for the decommissioned SF decreases with increasing distance between the sample collection points and the closest side of RM storage facility (RM-SF). Total Hg concentrations in RM leachate, surrounding surface water and groundwater all exceed Grade III limits of ChinaÆs Environment Quality Standards for Surface Water and Groundwater. However, the air quality was little affected as the daily average of TSP in the air is below grade II values of Chinese Ambient Air Quality Standard.CITATION :Wen, Z, Ma, S, Zheng, S and Zhang, Y, 2012. Assessment of environmental quality impacts caused by red mud storage facilities in China, in Proceedings Life-of-Mine 2012, pp 51-58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By A D. Price, W J. Germs, O Patterson, T R. Weaver

"Understanding controls on groundwater and surface water flow and quality at mine sites throughout all mine stages is critical to effectively manage environmental impacts over the entire mine life. Monitoring forms is an essential component of this proof of understanding. Typically, monitoring programs at mine sites have been developed in the framework of existing conditions. However; recognition of the challenges of climate change and the performance of mines during recent extreme events in Australia has highlighted the need to develop monitoring programs that are resilient and responsive to changing environmental conditions. Water monitoring programs need to be effective under a range of environmental conditions, potentially not historically experienced.This emerging challenge requires cross-disciplinary teams to work together to understand issues including: representativeness of background conditions to longer-term conditions at the mine site sensitivity of mine and closure designs to changing climate and hydrologic conditions methods of performance (eg water quality or quantity) failure during extreme climate events such as flood or extended drought.These understandings come together in a detailed conceptual and, in many cases, numerical hydrologic model that considers the mine-water environment under a range of conditions. The groundwater, surface water and water quality monitoring programs that are developed from the conceptual model need to be sufficiently responsive to be effective in the face of such changing conditions, with results in turn informing the conceptual model. Extended drought, major floods and changing weather patterns can alter recharge and discharge areas, oxidation profiles and ultimately, the contaminant flux estimates that would have contributed to mine design parameters and performance. Unless these effects are considered in the spatial and temporal design of the monitoring program and within the parameters monitored, the resultant program may fail to capture data that are critical to evaluating environmental impacts from mine sites.Developing and implementing a water monitoring program that considers these issues can build confidence in mine performance under a range of conditions, leading to increased confidence by all stakeholders in long-term mine performance during and after closure.CITATION:Weaver, T R, Price, A D, Patterson, O and Germs, W J, 2013. Developing resilient water monitoring programs in changing climate conditions, in Proceedings Water in Mining 2013, pp 109-114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

The green field discovery of a two million ounce high-grade refractory gold ore deposit in the Indonesian Province of Sulawesi Utara, led Newmont to utilise its proven technical expertise in dry grinding and whole ore roasting to develop a 2000 tonne per day, 160 000 ounce per year operation in this remote and picturesque location.Located at an elevation of 250 in above sea level and ten kilometres to a deep water natural harbour, the hard rock open pit mine, process plant and infrastructure facilities were built to budget at a capital cost of US$132 million. The plant was commissioned with oxide ore, with the first gold poured in March 1996 and with refractory ore in January 1997. The operation rapidly met its production targets because of extensive forward planning and training programs developed for the local workforce. The presence of steep topography, fertile coastal plains, high rainfall, high seismicity of this location led to the decision to dispose of neutralised tailings in deep water off the coast instead of impounding tailings in a dam. This paper describes the development of the project and the challenges in developing a gold operation in a remote location which lacked infrastructure, the steps taken to ensure a smooth commissioning, and the selection of the workforce to operate a technically sophisticated facility.

Jan 1, 1997

By S Gossmann, J Barlow, S Denner

"Unconventional gas resources, including coal seam gas (CSG) reservoirs, can be located above and below aquifers that provide groundwater for agricultural, industrial, urban and other uses. Development of these resources may, therefore, lead to potential impacts on groundwater supply.Management of reservoir/aquifer interconnections necessitates a program of focused data acquisition. For example, groundwater transfer from shallow aquifers to underlying CSG reservoirs may occur where CSG-containing units subcrop beneath shallow aquifers, possibly at significant distances from operating wells.Arrow Energy is undertaking studies of connectivity between aquifers including an investigation in collaboration with the Queensland Office of Groundwater Impact Assessment to evaluate connectivity between the Condamine Alluvium (CA) and CSG-containing Walloon Coal Measures (WCM).The Condamine Valley hosts highly productive agricultural land with groundwater resources heavily utilised for irrigation. Water demand outstrips available supply and groundwater has been subject to restrictions on further development since the early 1970s. Developments that could have an additional impact on groundwater resources in the CA are of major concern to local landholders. This paper describes: planned field investigations at two sites: 1. Stratheden, where pumping from the WCM will be undertaken 2. Daleglade, where pumping from the CA will occur how the data to be collected from field investigations will be used to refine predictions of flux between the CA and the WCM.CITATION:Denner, S, Gossmann, S and Barlow, J, 2013. Planned field investigation of connectivity between the Condamine Alluvium and Walloon Coal Measures, in Proceedings Water in Mining 2013, pp 91-98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By A Tang, K Ringwood

"Water is increasingly being recognised as a material business risk that many companies are still not well-equipped to deal with. Despite a raft of water-risk focused initiatives, methodologies and guidelines, the challenge of managing the strong link between the technical and operational water issues, along with the growing external challenges and interests in water, remain a significant risk to a companyÆs ability to deliver value.This paper provides an overview of the key lessons learnt from ERMÆs experience of working with companies across a range of water sensitive industry sectors, in particular, the mining and oil and gas sectors, to develop and implement practical approaches to manage business critical water risk. These examples highlight the importance of managing water risk by linking technical and operational aspects of water management - with the longer term strategic and social license aspects. Four key ingredients were identified that are central to providing companies with a leading edge in the successful mitigation of water risk: understanding and evaluating water risk including the technical and operational aspects of water management, plus the longer term strategic and social aspects articulating a strong business case that prioritises water risks and their financial exposure to the organisation constructing a clear roadmap that practically links the water strategy objectives with on-the-ground implementation and action building capacity in the organisation to manage, engage and coordinate on water to mitigate risk.CITATION:Ringwood, K and Tang, A, 2013. Practical approaches to managing business critical water risk, in Proceedings Water in Mining 2013, pp 293-300 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By G F. Brent, S Hawke, M Rothery, P Dare-Bryan

Mine-to-mill studies have previously demonstrated downstream productivity benefits from relatively modest increases in blast energy, or powder factor. These increases have up to now been limited by safety and environmental constraints, since excessive blast energy can result in flyrock, unacceptable vibration, airblast and wall damage.Here, a new blasting method that overcomes these constraints is presented. For the first time it is possible to employ powder factors that are several fold higher than conventional blasting. Independent modelling has shown that such powder factors can potentially increase mill throughput by 20 to 40 per cent. The economic implications are substantial, both in terms of increasing production in existing operations and in consideration of capital and plant requirements for greenfield sites. In addition, mill electricity and grinding media consumption and their associated costs and energy and emissions penalties can be reduced.This method represents a step-change in blasting practices. It involves a novel design utilising dual blast layers within a single blast event, all initiated with state-of-the art electronic blasting systems. The energies in the lower layer can be as high as five times the standard energies, providing for intense fragmentation of the ore. Results from blast models have been confirmed in field trials of the method.Open cut gold mining, in particular, stands to benefit from this method. As gold grades decline, milling costs and throughput increasingly become constraints on production that can be alleviated with this new method. Additionally, it opens possibilities for improved recovery. Blast modelling studies show that dilution of gold ore within the blast can be managed with the new method. Furthermore, it has been shown that vibration from the new method is actually lower than from conventional blasting, allowing the use of the technique in proximity to mine highwalls and other key infrastructure such as underground orepasses.It is concluded that this new method could substantially increase gold mine production and profitability while reducing overall energy consumption and associated emissions.CITATION:Brent, G F, Dare-Bryan, P, Hawke, S and Rothery, M, 2013. Ultra-high-intensity blasting - a new paradigm in mining, in Proceedings World Gold 2013 , pp 395-400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

The maintenance system for underground mobile equipment at Cobar Mines Pty. Ltd. has been modified from that originally planned as a result of experience gained in operating the equipment.Downtime due to breakdowns has been reduced by improvement of vehicle servicing and overhaul procedures.Frequency of breakdowns can be reduced by training operating and maintenance personnel to a high standard, ensuring adequate numbers of tradesmen and supervisors, good maintenance facilities and communications, a well designed mine layout, and a comprehensive stock of spare parts.A maintenance and downtime summary is compiled for each four-week operating period and this is useful in highlighting particular problems where corrective action must be taken.

Jan 1, 1969

By J Battista, J Grace, I Brunton

The need to better understand and develop strategies to improve instantaneous shovel productivity at the Cadia Hill Open Pit Mine (CHM) instigated the development of the æShot to ShovelÆ project. This project has involved the implementation of a drill and blast (D&B) information management system to capture current and future experience. Equally important has been the manual monitoring of shovel productivity and direct use and analysis of high precision GPS and productivity data logged by ModularÆs Dispatch System. The analysis of this type of data was facilitated with the application of GIS based software (ie MapInfo). This has shown to be a powerful medium to display, interpret and assess this type of spatial information on a blast-by-blast basis. Cadia HillÆs well-defined D&B processes supplemented with the application of the above systems are providing a unique capability to assess and better understand the impact of both muckpile conditions and operator proficiency on instantaneous loading productivity. This is facilitating the definition of appropriate optimisation strategies in both drilling and blasting and operator proficiency training. This paper gives a summary of the work conducted in the æShot to ShovelÆ project, describes the engineering tools being implemented and discusses preliminary findings and their practical implications.

Jan 1, 2004

By M I. Pownceby, J Manuel, S Suthers, A Poliakov, E Donskoi, N Ware

"The mining industry is constantly seeking methods for optimising the exploitation of mineral resources, such as iron ore, in a sustainable and eco-efficient manner for economic and social benefit. When faced with resources that have mineralogical or textural complexity, poorer grades or geological variability, it is particularly important to apply a comprehensive geometallurgical approach to the development of the mining operation, from resource definition through to processed product. Integral to this approach is the quantitative characterisation of representative samples across the whole orebody.A key factor that associates the geological characteristics of iron ores to their processing response is ore texture. While the classification of samples on the basis of chemical or physical properties alone is often not sufficient to predict their processing behaviour, classification and quantification of texture types can be effectively correlated to metallurgical performance in processes such as blending, beneficiation, pellet making, sintering and ironmaking. This paper describes some of the research conducted by CSIRO pertaining to the design and rationale of a texture-based classification system for Australian iron ores; some of the tools developed and used to apply such classification; and the application of the generated data to quantifying, modelling and predicting sintering behaviour and performance in the blast furnace.CITATION:Suthers, S, Pownceby, M I, Manuel, J, Ware, N, Donskoi, E and Poliakov, A, 2016. Geometallurgical Characterisation of Australian Iron Ores – from Ore to Processed Product, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 351–360 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By R Dunne, J Dodd, J Snyder, F Roberto

Energy costs are steadily increasing worldwide while the availability and quality of water are becoming contentious issues between the users (municipalities/households, agriculture, manufacturing and mining). Refractory gold ore treatment - pressure oxidation, biological oxidation and roasting (ultra-fine grinding, or UFG, will not be discussed here as this process only reduces the particle size of the feed prior to cyanidation) - requires substantially more energy and water quantity and quality are vastly different compared to the standard and simple flow sheets used for treating non-refractory ores This paper will provide an overview of the energy and water requirements for treating refractory gold ores, a topic which does not appear to have been considered previously in the literature.CITATION:Roberto, F, Snyder, J, Dodd, J and Dunne, R, 2013. Energy and water requirements in the treatment of refractory gold ores, in Proceedings World Gold 2013 , pp 527-532 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By J Y. C Lo

The construction of two drainage tunnels and the associated subvertical drain system at the Po Shan area in Hong Kong was completed in December 2009. This project is the first of its kind to utilise drainage tunnels and a network of subvertical drains to regulate the groundwater table to enhance the long-term stability of the hillside of Po Shan area.The groundwater levels, monitored by preinstalled piezometers, once exhibited dramatic drops during drilling of the subvertical drains; however, have recovered from natural replenishment after effectively plugging of the drains. The level of groundwater drawdown is in line with the design function of the subvertical drains. In order to understand the groundwater flow pattern in the Po Shan area during and after construction and to set out operation schemes for the subvertical drain system so as to control the groundwater table in the Po Shan area, a post-construction review has been carried out to examine the behaviour of the drainage system and its impact on the surrounding subsurface groundwater flow.This paper presents a review of the groundwater monitoring data during and after the construction of the drainage tunnel system covering a period of over 3.5 years. A simplified conceptual hydrological model is developed, which has been verified by the monitoring data, to capture the key elements with regard to groundwater variations in different stages of the construction. The performance of the tunnel and subvertical drain system as revealed from these field measurements is discussed.

Mar 8, 2011

By P Jackson, J Rea, M D. Goodz

The Morning Star Gold Mine has operated over a 101-year period, producing gold from narrow quartz veins and sulfide stockworks hosted mainly within a dioritic-gabbroic dyke. The deposit has been developed over a vertical depth of 980 m with drilling extending the vertical depth to greater than 1200 m. Currently there is a total Inferred Resource of 4.6 million tonnes at a grade of 6 g/t for 910 000 ounces of contained gold resources, which comprises an underground project and a surface project. Significant variation exists between the grade of drill core intersections and that observed in face sampling and subsequent production reconciliation (250 - 650 per cent). Studies were carried out on ten major production reefs, where the grades of drill intercepts were compared with face samples collected during development and mining. The implications of this study have been used as justification to assign production or stope/development grades where applicable to resources that are direct extensions of the historical development headings. Grade assignment and its impact on sensitivity for gold resources are detailed and show a 40 per cent variation in the gold resource, depending upon whether a production or calculated stope grade is used in grade assignment for the major reef deposits. Recent diamond drilling has intersected approximately 40 new gold bearing quartz reefs and sulfide zones that contain all the key mineralogical and structural indicators, and traditional large variations in gold grades similar to the historical major production zones. The implications of grade factoring and grade assignment are the greatest challenges confronting the resource estimation team in defining grade for these new zones. Grade assignment is seen as a method of balancing known historical production observations with the irregular grade distribution inferred from drill core assay results. Ongoing mine development and bulk sampling works are planned to validate the grade assignment process. The first stage of this process is the trial mining of the newly discovered Maxwell Reef (MR). The stope drawpoints were completed in August 2008 and the MRS1 stope is scheduled for completion in September. The stope reconciliation results will be presented at the October 2008 conference.

Jan 1, 2008

By M P. Sandy, J B. Albrecht

"Narrow vein mining can be loosely defined as mining operations involving orebodies with a true thickness of less than 4 m. Some authors have limited the term to steeper-dipping orebodies where the ore will rill under gravity. However, ænarrow veinÆ can also legitimately refer to some of the flatter orebodies, such as many of the platinum, chrome and gold deposits of Southern Africa, and several in Australasia including Bullen (at Norseman), Sunrise Dam, Telfer (Patterson, 1993) and the famous æflatmakesÆ at the Emperor Gold Mine in Fiji (Gordon and Harmse, 1993). Where the orebody dip is less than about 40¦ additional effort is usually required to remove the broken ore, including the use of scrapers, hydraulic monitors or remote-operated excavators (Tombs, Buckingham and Hancock, 2008).Working in such narrow orebodies presents particular operational and geomechanics challenges. A range of mining methods have been developed or adapted to exploit narrow orebodies including:cut-and-fill,narrow vein bench or longhole stoping,Alimak stoping,shrinkage stoping, and methods for shallow dipping orebodies (including Airleg and mechanised methods).The paper discusses some of the advantages and disadvantages of each method with a focus on geotechnical aspects including mining sequence options, stress management, ground support requirements, dilution and recovery.CITATION:Sandy, M P and Albrecht, J B, 2012. An overview of geotechnical issues in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 185-194 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By P Mikula, R Geranmayeh, R Carlton, M Ferguson, R Whiting

The concept of using specially designed slot blasts to mine through stress abutments that intersect faults, while controlling fault-slip seismicity, has come of age at Mt Charlotte Mine. Due to the high and adverse stress field and the presence of major faults, the mine is vulnerable to significant fault-slip seismicity. As mining proceeded, advancing stress abutments around various mined areas encroached on several major subvertical faults. If the sequence formed a diminishing pillar between stope and fault, the removal or failure of that pillar daylighted the fault, and often resulted in significant fault-slip seismicity. A new strategy called ‘Tight Slot Blasting’ (TSB) was developed to restrain or dampen this style of fault-slip movement. The TSB has geometric similarities to a conventional cut-off slot used to create stress shadows, but its function is different. Its objective is to trigger and control a sudden shift of the stress state on a fault from an initial stable state, through an unstable transition, to a second stable state. A TSB firing advances a long tall narrow slot through a stressed abutment between a stope void and a nearby fault, using a rapid blast with a low swell ratio, so that the slot substantially and rapidly fills with blasted rock fragments. During the blast process, the stressed rock is rapidly removed and transformed into the fragmented rock fill in the slot. The strategy deliberately allows a fault-slip episode to manifest at a chosen time and place. The tight-packed broken rock in the slot performs an essential shock-absorbing function by controlling the slip amount and rate on the fault, while at the same time the fill becomes compacted by the movement. This controls the dissipation of fault-slip energy, and greatly reduces the seismic response in time and space. A small closure across the slot occurs, with consequent relaxation and destressing of the adjacent rock mass. Stress monitoring data shows that slot creation lowers the abutment stress in the nearby rock mass, while the newly placed fragmented rock fill acts as a shock absorber, providing considerable resistance to substantial fault-slip movement that otherwise could deliver a significant seismic event. First used in 2007, the strategy has been refined to become a routine specialised practice for management of seismically hazardous situations at Mt Charlotte, with 12 successful TSBs conducted to date. Despite mining through multiple high stress abutments, seismic reactions have not exceeded ML 2.1 with any TSB firing, all remaining below the site tolerable maximum of ML 2.3. This paper presents an overview of the strategy, and five case examples of the strategy in critical stressed areas in July 2016, Sept 2017, Dec 2017 and two in Oct 2020. The strategy has successfully managed the seismicity and is expected to remain an essential part of the seismic management plan at Mt Charlotte Mine.

Nov 29, 2022

By Q Zhou, G Barrett, Y Choi, J Jiang

As part of a general review of processing double refractory ores through Barrick GoldÆs autoclaves /carbon-in-leach (CIL) facility at Goldstrike, a study was made to evaluate the use of surfactants for reducing the loss of gold during cyanide leaching of preg-robbing gold ores. Consistent improvement of gold recovery was observed with surfactants at various testing conditions. This paper will discuss the results obtained from laboratory and pilot-scale testing, as well as, review potential mechanisms for the observed improvement in gold recovery.CITATION:Zhou, Q, Barrett, G, Jiang, J and Choi, Y, 2013. Surfactants for gold recovery improvement with preg-robbing gold ores, in Proceedings World Gold 2013 , pp 367-372 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By P S. Jaitawat, M Sarim, M P. Roy, P K. Singh, A Joshi

Mining is being carried out using the sublevel open stoping method at the Kayad underground mine. The mine will ultimately reach a depth of 390 m. Kayad village is only 100 m (horizontally) from the underground mining areas. As a result, blast-induced ground vibration is one of the major issues for the residents of the village. This paper deals with the process involved in optimising blast design parameters at the development face blast, slot raise blast and ring hole blast to control blast-induced vibration within safe limits while ensuring improved production, productivity and safety. In total, 1041 development face blasts, 110 slot raise blasts and 52 ring hole blasts were conducted, and 2612 vibration data were monitored in the village at different locations. Initially, electronic delay detonators were used, with an emphasis on controlling vibration in the surface structures. Subsequently, shock tube (Nonel) initiations were used as the blasting faces reached lower depths. A comparative study was also performed for both the initiation systems. The orebody width generally varied from 3.1 to 7 m, and ring hole designs were optimised accordingly. The number of holes in a ring was up to seven and the depth was up to 23 m, depending on the size/width of the orebody. The ring blasts were performed with 64–340 kg of emulsion cartridge explosive and detonated with explosive weight per delay of 10.92–17.16 kg. Extensive experiments were performed and blast-induced vibrations were controlled in the village. Deck blasting (ie up to four explosives decks) was used in a blasthole and the explosive charges were separated by delay detonators, which helped to control the vibration in the village. The actual detonation time of each deck was recorded by monitoring the in-hole velocity of detonation of the explosives, and the charging patterns were optimised accordingly to get the desired blast results.CITATION:Roy, M P, Singh, P K, Sarim, M, Jaitawat, P S and Joshi, A, 2015. Blast design and vibration control at Kayad lead-zinc underground mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 533–544 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015