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By D Preedy, J K. Claflin, S R. J La Brooy

This paper summarises the lessons learned during a recent carbon reactivation kiln upgrade project at the Sukari Gold Mine in Egypt. The kiln is being replaced to ensure that the plant achieves full value from the current throughput expansion from 5 to 10 Mt/a.The suitability of the original engineering design criteria for kiln selection and the adequacy of the original kiln are reviewed in the light of the carbon chemistry, operating experience and a site inspection of the kiln. Particular aspects of the reactivation facility are discussed including: predrying, preheating, feeding, gas seals, kiln heat transfer, steam injection, counter-current sweep gas flow, carbon cooling, fines minimisation and removal.Design criteria for a carbon predryer, reactivation kiln and cooler combination for carbon heavily fouled by high molecular weight frothers and collectors are discussed and the abridged Ausenco datasheet for the combination is presented.Responses to a request for a budget price sent to most of the worldÆs suppliers of carbon regeneration kilns are summarised.CITATION:Claflin, J K, La Brooy, S R J and Preedy, D, 2013. Ausenco carbon reactivation design criteria, in Proceedings World Gold 2013 , pp 401-410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

In recent years there have been many changes in mine ownership due to the on-going rationalisation towards larger mining companies. Larger companies inevitably find it hard to manage small mining operations and in many cases smaller mines do not fit corporate resource, production and profit criteria. Smaller companies are more suited to managing these medium or small scale mines and are tendering for the purchase or lease of mines that larger companies wish to dispose of. In addition to these factors there has also been a trend (especially in Western Australia) for mines to continue operating at ever increasing depths. This in turn has led to more mines operating in high stress environments and experiencing damaging seismicity. Assessing the viability of seismically active mines from a takeover or purchase point of view should involve analysing the risk profile of every aspect on mining that could be affected by adverse seismicity. This includes assessing current and alternative mining methods, mine designs, support systems, extraction sequencing, monitoring and blasting. This paper includes discussion on items that need to be assessed when considering the purchase of seismically active mines, with experience gained from some recent studies in Western Australia. In these cases it was apparent that quantification of previous seismic history on itÆs own was a totally inadequate method of assessing minewide seismic risk potential. A more holistic approach is required, taking into account all aspects of relevant data, all the minewide effects of seismic activity and all possible means of mitigating those effects.

Jan 1, 2002

By R Bose, M Bovell, G Cheong

Grinding media is a major consumable in mineral processing and therefore decreasing costs associated with its consumption is regularly considered a key goal for the minerals processing industry. Grinding media manufacturers have historically developed steels with improved wear life for their products as a way of delivering incremental media quality improvement. This has included increasing carbon levels from low-to-medium carbon steels up to the eutectoid carbon composition of 0.77% where the relationship between higher carbon and better wear performance is well understood. Producers today will regularly use grades in excess of 0.8% to further improve wear performance particularly for rolled grinding media.This paper first introduces the demonstrated relationship between this increased carbon content and improved wear resistance along with metallurgical rationale behind the high carbon production process and limitations. To test the performance improvement associated with the higher carbon steel grade, a series of Marked Ball Wear Tests (MBWT) were carried out. This paper also explores the relationship between ball properties, test methodology and wear performance and concludes by correlating increased carbon grade with a reduced consumption rate of between 3.1% and 6.1% in the tests conducted.CITATION:Bovell, M, Bose, R and Cheong, G, 2018. Improved forged grinding media performance with carbon content greater than 1.0%, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 559–570 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By S Talu, E Savage, S Howe

Major falls of ground, strainbursts, airblast and mudrush events are the major hazards in block caving environments, resulting in both safety and financial consequences and losses. Rio Tinto mines have developed strategies to reduce the likelihood of these events occurring. However, until recently, there have been no tools available to monitor and manage these hazards in real time.Mira Geoscience and Rio Tinto have collaborated to develop real-time geohazmaps to monitor and manage major cave hazards. These geohazmaps are used by mine planners to integrate multiple hazard parameters that contribute to form a combined hazard rating.The benefits of implementing geohazmaps include safety and cost improvements through the early identification of potential locations for major events. These cost savings are realised in the design phase, where development and critical infrastructure is located in areas of lower hazard rating. Additional improvements can be achieved by taking the hazard level into consideration when planning the production and development schedules and ground support design.CITATION:Talu, S, Savage, E and Howe, S, 2016. Geohazmap implementation in block cave mines, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 817–822 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By H Ishikawa, S Palaniandy

The gravity-induced stirred mill such as the TowerMill is an energy-efficient grinding solution used in secondary, tertiary, and regrinding duties in the mineral processing concentrator. The interest in this technology is emerging, with more than 300 mills installed globally in various grinding duties and commodities for the last 30 years. Although the technology is matured, there are still opportunities for improvement and the development of new knowledge to improve its circuit energy efficiency and reduce water consumption. Recent studies show that a combination of stress intensity, ore hardness, slurry density, and mill feed configuration can be used to evaluate the performance of the grinding circuit. A recent pilot-scale TowerMill test work at various stress intensities shows that a lower operating work index and size-specific energy were achieved at higher agitator tip speed and using medium size grinding media. These outcomes were confirmed through several site trials. A smaller 17 mm grinding media has reduced the operating work index and size-specific energy by 18 per cent and 11 per cent, respectively, compared to the 20 mm in a magnetite concentrator. Moreover, the conversion from top feed to bottom feed configuration has reduced the operating work index and size-specific energy by 13 per cent and 37 per cent, respectively. The circulating load was reduced by 34–38 per cent, leading to a reduction in the dilution water consumption in the hydrocyclone feed sump by 20 per cent. A variable frequency drive offers flexibility to change the stress intensities on the TowerMill, where a 35 per cent reduction in specific energy was achieved when the ore became soft. This paper explores the potential design and operating strategies that can be implemented to enhance the energy efficiency, reduce water consumption and reduce CO2 emissions in the circuit and finally evaluate its impact on the total cost of ownership.

Aug 24, 2022

By S Bhandari

This paper is a step in the direction of developing a computer model of the near source dispersal of suspended particulate matter (SPM) in planetary boundary layer (PBL). Since Surface Mine blasting is done during daytime, study of daytime dispersion in convective boundary layer (CBL) is relevant to the mining engineers. The scope of this paper covers dispersal after the blast in any type of PBL ie stable, convective and neutral but only under weak wind condition. Mathematical analysis of the dispersion of vertical dust column has been carried out during weak wind conditions in a tropical meteorological environment. It is noted that dust concentration reaches its maximum value some distance away from the point of blast, immediately after the blast (t*=1) and thereafter rapidly decreases. After a short interval from the time of blast at t*=11 the dust concentration shows linear decrease in concentration with distance. Dust concentration also rapidly drops during the interval t*=1 to t*=11, thereafter, rate of drop is nearly the same at any distance from the point of blast.

Jan 1, 2001

By E Coffison, M Gibbs, C Bennett

The sustainable management of surface water associated with coal mining and coal seam gas projects is a considerable factor affecting the global competitiveness of these resource companies operating in Australia. Management of surface water can be costly, but effective water management and hence environmental stewardship enhances corporate social responsibility and the social license to operate. The surface water issues for the two industries are comparable, yet there is currently a lack of alignment between how Queensland, where the majority of AustraliaÆs coal seam gas projects are located, manages and regulates water on coal mine projects and coal seam gas projects.This paper provides a high level comparison of Queensland legislation and highlights the lack of alignment of this legislation regarding surface water management in these two industries. Through a case study, it looks at the surface water management process at a coal mine site based on the current legislation and principals of surface water management. QueenslandÆs lack of alignment in legislation regarding surface water management in these industries is understandable given the different development paths and time scales of the two industries. The coal mining industry has developed over a long period of time and the legislation has progressed in parallel, whereas, the coal seam gas industry is relatively new in Australia and the legislation has had to advance quickly. The lack of alignment between management of surface water for the two industries creates confusion among stakeholders and this adds complexity and additional transaction costs during the exploration, permitting and operational phases of projects, including landowners who may be affected.CITATION:Bennett, C, Coffison, E and Gibbs, M, 2013. Lack of alignment between regulation of surface water management in coal mining and coal seam gas, in Proceedings Water in Mining 2013 , pp 157-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

The Resource Management Act has been in force now for approximately ten months. This Act, and the Crown Minerals Act which accompanied it, have substantially changed the manner by which mining operations and other resource uses obtain access to resources and are subject to controls of their environmental effects. This paper briefly summarises the key elements of the regulatory provisions of the Resource Management Act. It identifies the types of resource consents required, and discusses these and procedural matters in relation to mining in Otago. It addresses the transitional provisions and highlights inconsistencies and difficulties in the implementation of these provisions. This paper identifies potential future developments in the planning and regulatory environment relating to mining in Otago.

Jan 1, 1992

By R Ayothiraman

Tunnel excavation may induce adverse effects on nearby existing structures/foundations in urban areas. Accurate prediction of tunnelling effects on pile foundations of nearby structures in the urban environment poses a major challenge during design. Several studies have been undertaken to understand the mechanisms of the soil-tunnel-pile interaction, which focused only on influence of tunnelling on nearby existing building and foundations. However, effect of pile loading on existing tunnels did not receive enough research attention so far. So it is essential to measure the response of existing tunnel-lining due to loading on newly constructed pile to assess to the safety against the additional forces/moment caused by pile loading and to evaluate the critical distance for the proposed construction of any structures from the tunnel location. This paper presents result of three-dimensional (3D) finite element analysis carried out in ABAQUS to investigate the effects of pile loading on existing tunnels embedded in cohesive soil. It is found that the effects on tunnel lining depend on horizontal separation distance between pile and tunnel as well as location/elevation of pile tip with respect to tunnel location.

Mar 8, 2011

By S Mitra, B J. Monaghan, T Honeyands, G Evans, R Chowdhury, D Scimone

Due to the harsh operating conditions, wearing of the inner refractory lining in a Basic Oxygen Steelmaking (BOS) furnace reduces the useful life of the refractories and incurs a significant cost component for relining. In this study, firstly, a combined compressible and incompressible computational fluid dynamics (CFD) model was developed to identify the potential wear prone zones in an industrial scale BOS system during the supersonic oxygen blowing phase by quantifying the wall shear stress distributions. Next, the retained slag splashing process was simulated by introducing an inert gas to residual slag mass to achieve a protective coating on the refractory walls. Effect of both design and operational parameters such as lance head configuration, lance position and the initial slag volume on the slag wall coating performance were quantified and most favourable conditions were determined.

Jun 19, 2024

By B Wu, C Zhao, B Lei

At present, the friction factor is calculated by measuring pressure drop and airway configurations. However, the workload of on-site measurement is heavy, and the measurement results are easily disturbed by the external environment. In order to meet the need of intelligent ventilation to quickly and accurately obtain the friction resistance of roadway. Based on the important of roughness in Atkinson friction resistance formula, in this paper, fractal theory is used to characterise the 3D rough surface, and a method based on fractal dimension to describe the roughness of roadway surface and calculate the friction resistance was proposed. A computational model of friction resistance for fractal characterisation of roadway 3D rough surface was established. The parameters of the model were deduced and verified by using Nikuradse experimental data. The fractal dimension of roadway surface was calculated by 3D laser scanning data of Kailuan roadway, the established friction resistance calculation method was compared with the field resistance measurement results. It is considered that the calculation method of friction resistance based on fractal theory is reliable and can well represent the influence of 3D rough surface characteristics of roadway. The result show that the new established friction resistance formula compared with the traditional Atkinson formula in Nikuradse experimental, the average relative error is 6.874 per cent, and compared with the measured results of ventilation resistance in Kailuan experimental roadway, the relative error is 6.667 per cent. Comprehensive evaluation and analysis suggest that the new formula can well reflect the influence of 3D rough surface on friction resistance, combined with 3D laser scanning technology, the friction resistance of roadway can be calculated quickly and accurately. This research provided a reference for the key technology and theoretical development of intelligent ventilation parameter measurement.

Oct 12, 2022

The BHP Billiton Cannington Mine uses paste as the principal method of backfill. The paste consists of mine tailings and cement. The pastefill process at Cannington includes a surface plant where the thickened total tailings stream is filtered using two vacuum disc filters operating in parallel. The filter cake is mixed with Portland cement in a spiral mixer to produce a paste at a specified yield stress and cement content. The initial system design only required paste to be delivered under gravity. In July 2001, Cannington Mine expanded to 1.8 million tonnes per annum. In order to achieve this, production commenced on five new levels underground, 350 metres horizontally from the paste plant. Due to the high viscosity of paste, this distance was too far to transport by gravity. Traditionally, paste has been transported only short distances (50 m) using positive displacement pumps, with very limited success. At Cannington, a conveyor was installed which was designed to achieve zero spillage into the environment. This paper discusses the innovative design strategies used to attain zero harm on the environment whilst conveying a material, which is difficult to transport.

Jan 1, 2002

By D J Maconochie

The use of rock bolts as permanent support has been prohibited by client specifications in several recent large tunnel projects in Australia. The justification for this appears to lie in concerns with proper and verifiable installation procedures rather than concerns with the intrinsic durability of the corrosion protection systems. However, in civil tunnels, preventing the use of permanent rock bolts for long-term support results in the use of cast in place concrete lining which in some instances would otherwise be unnecessary.

Mar 8, 2011

By A Grace, C Sennersten, A Davie, R Lyu, C A. Lindley, O Goldstein, T Thomas, L De Macedo Camargo

Block modelling is a well-established method for modelling ore reserves as a basis for strategic mine planning and mine development. Off-Earth mining, particularly of asteroids, can benefit from block models; however, the significantly different characteristics of asteroids and their methods of mining require reconsideration of the geometry and annotations of block models. Terrestrial block models consist of rectangular prisms within Euclidean coordinate systems. Their labels and parameters typically include location within a mine-specific coordinate system, x, y and z dimensions, specific gravity, hardness, grades of metals of interest and so on.These data provide an input to mine design and strategic mine planning. Mining asteroids may require different coordinate systems (eg spherical, elliptical or cylindrical, rather that Euclidean) and attributes that vary from Earth-based block models. These include: variable gravitational vectors throughout the block modelrotational moment or accelerationrotation rates. Materials within asteroids may show different isotopic compositions. Asteroid mining has the unique characteristic of a mine being identical with an asteroid. The position of the asteroid/mine in space and its full orbital elements provide critical inputs to mission design and costing. Hence, the block model concept needs to be extended with this metadata. The orbital position and behaviour of the Earth must be included for active mine planning, and increasing automation of mine planning and operations needs to consider terrestrial weather and telecommunications infrastructure. Financial planning requires analysis of the net present value of extraterrestrial mining compared with terrestrial alternatives, so a fully automated mining enterprise should integrate terrestrial and extraterrestrial block models at different scales and resolutions. Blocks can be indexed via octrees, allowing for hierarchical scales that support analytics for deriving new knowledge and correlating features across different scales.CITATION:Lindley, C A, Sennersten, C, Davie, A, Goldstein, O, Lyu, R, Grace, A, Evans, B, Pentecost, D, Thomas, T, De Macedo Camargo, L, Craig, J, Salomao, G N, Hellicar, A, Biggins, D, Timms, G, Coombe, M, Shahriar, M S, Smith, G and Rahman, A, 2015. A multilayer 3D index tool for recursive block models supporting terrestrial and extraterrestrial mine planning, in Proceedings Third International Future Mining Conference, pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By A Scott, S Kanchibotla, J Segui

The æMine to MillÆ concept is not new. In fact, it is the underlying objective of every mine. Unfortunately, in many operations the management structure and reporting systems have created independent æbusinessesÆ within the overall mining enterprise. This has created incentives to optimise the performance of each component of the operation rather than the enterprise as a whole. The Mine to Mill Conference organised by The AusIMM in October 1998 documented a number of case studies where run of mine ore was not presented to the mill in the best possible form for subsequent stages of comminution and processing. A number of examples were quoted where modest expenditure in the mine had a very significant impact on downstream process efficiency and hence costs. Examples included:the minimisation of fines in the mining and handling of iron ore; the management of fines in blasting and crushing for a copper heap leach operation; the control of blast damage, mining recovery and dilution in open cut coal operations; and the optimisation of mine fragmentation to increase mill throughput in gold and copper operations. The latter topic has been trialed at a number of mines and is referred to as æMine to MillÆ fragmentation. A number of æMine to MillÆ type investigations have been reported in the literature including Pease et al, Simkus and Dance, Nielsen, Scott et al, Kojovic et al, Kanchibotla et al, Bulow et al and Hawkes from the 1998 Mine to Mill Conference. In addition, a number of studies are in progress or the results have yet to be published. These studies have demonstrated the feasibility of obtaining the data required to characterise the breakage behaviour of ores and to model the impact of changes to blasting practices on process efficiency. Characterising the breakage behaviour of ores is a vital step in the management of fragmentation and comminution in mines. The characteristics of importance to fragmentation fall outside the parameters conventionally required to describe the economic geology of a deposit. æMine to MillÆ optimisation of fragmentation means that the mining engineer needs information from the geologist in order to be able to help the metallurgist. Providing this information requires close interaction between these groups.

Jan 1, 2000

By Kentwell D. J, Cusak C. J, Harvey-Kelly F. E L, M D. Goodz

The Morning Star Gold Mine presents an example of a prolific operation with considerable historical records, mine workings, drill hole logs and countless plans from greater than 20 adjacent mines which have now been consolidated to form the current project. Implementation of 3D computer modelling in the planning stages has provided an additional tool to integrate and refine geological models as a guide to some exploration strategies. It has allowed for a re- interpretation of the host rock units, dimensional constraints, new exploration extensions and provisional resource modelling. The initial consideration of this project was to integrate 135 years of mining history into a single database. Each historic mining area had an unrelated mine grid, often established parallel to the long axis of their main stopes; some were based on magnetic or true north. Survey plans were in chain, imperial or metric units. Through the manipulation and rotation of old grids, previously unrelated mine workings began to form continuous mineralised zones, with unmined portions still remaining in between the existing development. Furthermore the current drillhole database of >433 holes showed numerous confirmatory intersections of new mineralisation. A series of tiered tables were created within a relational database to derive guidelines for assessing data to attribute a Mineral Prospectivity Value [MPV] based on key indicators of mineralisation. Indicator logging now forms the basis of geological descriptions.

Jan 1, 1997

By S J Riley

The cover (cap) over the tailings pit at Nabarlek uranium mine must be structurally stable as it will act as a barrier to radon gas emission and have to contain other long-lived radionuclides. Structural stability is primarily an issue of erosional stability in the context of a design life of thousands of years. The primary agent of erosion is fluvial, dominated by rainwash, overland flow, filling and gullying in the local area. Other agents of erosion are of less concern although biogenic agents of erosion (eg termites and windthrow) may enhance fluvial activity. Several methods may be used to assess erosional stability. They fall into two main categories, namely erosion modelling and geomorphic modelling. The former is illustrated by the Universal Soil Loss Equation in which parameters describing aspects of the geotechnical and hydrological properties of the rehabilitated surface are used as input for the modelling of erosion rates. The latter is illustrated by estimates of gully and valley erosion using empirical models. Estimates of the erosion rates and stability of the Nabarlek cover are presented. The two main techniques are complementary and it is argued that rehabilitation design must make use of both approaches when estimating erosion and geomorphic stability. More recent developments in geomorphic modelling using numerical techniques incorporate both approaches.

Jan 1, 1994

By S Lloyd, J Chow, S Fitzpatrick, D Greenup

The Tropicana deposit was discovered in 2005 after AngloGold Ashanti followed up an unexplained gold-in-soil anomaly. Discovered in a remote, barely-explored area of Western Australia not previously thought prospective for gold, Tropicana is the most significant gold find in Australia for more than a decade. The new, large scale open pit gold mining operation will produce an annual production of around 330 000 to 400 000 oz over a ten year mine life mining around 60 Mt/a.Process plant construction started in early 2012 and is due to finish in the December 2013 quarter. The mining contract was awarded to Macmahon Holdings (Macmahon) and mining commenced in July 2012 using conventional drill and blast, truck and excavator open cut methods.As a construction and start-up project in a greenfields location, the establishment of mining activities at Tropicana Gold Mine (TGM) involves the implementation of technical and operational systems, including the mining contract. Some of these systems and likely challenges were identified during earlier studies, while others were not foreseen until they were encountered. Alternatively, the time frames around implementation change depending on the changing knowledge of the project and industry environment. These systems include those common to the industry and those specific to the operation and location.This paper examines the implementation and development of a number of the systems specific to the establishment of mining operations, including the history, process and some outcomes. Although expected to be discrete systems to implement, they become interdependent. This linkage between systems further offers challenges and opportunities for the continuous progress of each system and for TGM as a whole.CITATION:Chow, J, Fitzpatrick, S, Greenup, D and Lloyd, S, 2013. Tropicana Gold Mine - mitigating the challenges of a mining start-up, in Proceedings World Gold 2013 , pp 51-60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By H Allday

The mining industry’s attention has shifted over the last decade with the recovery from the downturn resulting in greater development of innovation and new work methods in a bid to remain competitive and deliver higher productivity. The emphasis on cost reduction to improve profit margins has primarily been the focus of the “work smarter” campaigns embraced within the industry. But is this strategy holistically the best-for-business, or does it place a ceiling on revenue opportunities and inhibit mining companies from truly maximising value? Businesses need to maintain a balance between active cost management and revenue generation often resulting in cost reduction strategies at site level. These strategies have merit, assessing areas of cost wastage across operations and creating space for opportunity. However, this potentially can create distractions from the goal of enabling growth and lead to the sacrifice of quality and delivery. Focusing too heavily on cost reductions without addressing revenue generation is an unprofitable lens to look through, and the relationships between cost, revenue, quality and profit margin can often be overlooked resulting in missed opportunity to maximise value. How these relationships are effectively employed by mining companies to reap the rewards from an overarching corporate perspective down to site level remains a fluid concept depending on the nature, operating market and strategy of the business. A common directive from businesses to their operations is to strive for greater profitability and productivity. The quantification of these requirements, and the nature of the cascading message delivered, impacts the methods employed by the operational team to meet the expectations of the business. Cascaded strategies, if not delivered with appropriate participation and buy-in can often be perceived to be knee-jerk and create frustration for operations who are squeezed to deliver on expectations by slashing site costs. This squeezing is not only felt by the mining operation but at the individual level and can result in increased team stresses. In some cases, this may also steer behaviours towards activities that result in corner cutting and an elevation of operational risk, potentially increasing associated incidents and injury. Driving down costs by any means can create an unhealthy tunnel vision where value is no-longer assessed for best-forbusiness results. By flipping the viewpoint to a value-based approach revenue opportunity may be realised and potentially exceeded, however this opportunity may be missed if value is over shadowed by a cost heavy focus. By analysing a selection of real operational cases (ranging from mining contractors through to in-house mining giants), it becomes apparent that practical revenue maximisation strategies are not only key to an increase in value and cash flow but to a stronger understanding of business drivers for sites and operators alike. In the cases evaluated additional revenue opportunities are foregone in favour of cost reduction strategies resulting in negative impacts on the associated operations and wider businesses. Alignment towards value generation is king. If strategies are not implemented focusing towards value and revenue maximisation, the opportunity loss experienced by mining operations could continue be great and the question should be posed; when the next up-turn hits will operations be ready to reap the rewards or still have a glass ceiling above their heads?

Mar 15, 2021

By L Tatnell, R Mackay, A Tolooiyan

The multi-reversal direct shear test (MRDS) method is commonly used to measure the residual shear strength of soils. However, when the standard direct shear (DS) apparatus is used, the MRDS method is prone to two major sources of error: load cap tilting and specimen loss. These two sources of error can cause erratic behaviour in the residual shear strength curve, making it difficult or even impossible to determine the correct residual shear strength value of the specimen being tested. This paper presents the results of new modifications to the standard DS apparatus that prevent load cap tilting and specimen loss. Consolidated drained testing was performed on highly-over consolidated cohesive soil samples from a Latrobe Valley open pit mine, with results obtained from the modified DS apparatus showing a great improvement in the residual shear strength profile compared to those obtained using the standard apparatus. Large numbers of reversals (up to 14) conducted on a single specimen in the modified DS apparatus showed no notable load cap tilting and no specimen loss occurred. The modifications are easily applied to the standard DS apparatus, and analysis and correction of the data are simple.CITATION:Tatnell, L, Tolooiyan, A and Mackay, R, 2014. Measurement of residual shear strength using a modified direct shear apparatus, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 425–434 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014