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By S Sims, A Stradl, G Hope, B Lacouture

Column flotation cells have been installed in numerous base metal operations around the world. The majority of these cells utilise conventional air-only spargers to introduce air into the bottom of the column. The recent development of instruments to measure the bubble characteristics in these columns has provided a renewed understanding of column behaviour. These new tools provided insight into why the columns at Red Dog Mine had never performed up to expectations. After efforts to optimise the spargers failed to substantially change the bubble size and air efficiency, alternate sparger systems were investigated. The Metso Minerals CISA Microcel sparger system appeared promising and was selected for a full-scale plant trial. The Microcel sparger system was originally developed for the coal industry at the Virginia Centre for Coal and Minerals Processing. In October 2003, a Microcel was retrofitted into one of two 3.66 m diameter flotation columns in the zinc retreat circuit at Red Dog Mine. The operation of the two different sparger systems in parallel allowed a detailed comparison. This paper discusses the performance of the Microcel based on the data collected during several detailed surveys. Bubble size measurements carried out in the pulp zone using the McGill University bubble viewer showed a significant difference in bubble size. The mean Sauter diameter of the bubbles decreased from 3.4 mm for the jetting-type sparger to 1.9 mm for the Microcel sparger. The overall recovery and the recovery by size fraction for both valuable and gangue minerals were compared. Paired t-tests demonstrated that the Microcel column produced a higher concentrate grade (0.6 per cent zinc absolute) and a higher unit recovery (2.8 per cent zinc absolute) than the existing Canadian Process Technologies Inc (CPT) SlamJet column. These improvements provided a payback period of 1.5 months for the $109 000 investment.

Jan 1, 2005

Electrochemical Behaviour of Massive Chaclopyrite Bioleached Electrodes in Presence of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus In this work, the monitoring of bacterial and chemical dissolution of massive chaclopyrite was evaluated using cyclic voltammetry (CV); the mineral surface was examined using scanning electron microscopy (SEM) and the elements were examined by Energy Dispersive X-ray Analysis (EDAX). The electrolyte employed for the electrochemical tests was the medium used to bioleaching the electrodes (3.0 g/L (NH4)2+SO4, 0.5 g/L K2HPO4, 0.5 g/L MgSO4+7H2O and 0.1 g/L Ca(NO3)2).The results showed differences in voltagramms carried out by Acidithiobacillus ferrooxidans and Acidithiobacillus caldus: In bioleached electrodes tested in the presence of Acidithiobacillus ferrooxidans, the anodic and cathodic current signals were larger than with Acidithiobacillus caldus. The analysis of CV results allowed attributing the different peaks observed in both the direct and reverse potential scanning to the oxidation of chaclopyrite to a secondary copper mineral (bornite, chalcocite and covellite) and its reduction via different non stoichiometric copper sulphides intermediaries. Surface evidences were observed by SEM, and chemical elements evidences were also investigated by EDAX.

Sep 13, 2010

By A M. Robertson, R Lefebvre

Air movement and associated oxygen transport through waste rock dumps has the potential to significantly enhance the rate of oxidation of pyrite-bearing material. While this is a desired outcome for most heap leach operations, airflow in waste rock storage facilities can result in significant increases in generation and acceleration of acid rock drainage. Hence, a good understanding of internal airflow through waste rock dumps is required to control ARD and minimise any associated liability. The principal mechanisms contributing to airflow and oxygen transport in a waste rock pile include: diffusion; advection due to a thermal gradient (chimney effect) and/or wind pressure gradients; and advection due to barometric pumping. While diffusion is typically limited to a near-surface zone of a few meters depth, advection and barometric pumping have the potential to move air (and oxygen) to much greater depths into the pile. In general, the more permeable the waste rock material, and the greater the height-to-width ratio of the waste rock pile, the greater is the potential for advective air movement. The reactivity of the waste rock material as well as the coarseness (hence air permeability), and the spatial variability of these properties within a pile, have a strong influence on the magnitude of thermally induced advection. In contrast, air movement due to barometric pumping is controlled by the waste rock porosity, changes in ambient air pressure and the heterogeneity of air permeability of the waste rock dump. Results of field monitoring and numerical modelling using TOUGH AMD are presented to illustrate the concepts on air movement in waste rock piles discussed in this paper. During the design and construction phase, airflow can be controlled by judicious placement of reactive waste rock and use of selective placement techniques to control the internal structure of the waste rock facility (eg introduction of horizontal layering, prevention of inclined, high-permeability, channels (æchimneysÆ)). Several closure measures are available to minimise airflow including: placement of a low-permeability cover to reduce air entry; and placement of a non-reactive cover material to isolate reactive material from the zone of active airflow and/or regrading of the waste rock pile to obtain a geometry and internal structure less susceptible to advective airflow.

Jan 1, 2003

By G J. Zhang

The shape and particle size distribution of caved ore mass in sublevel caving were investigated in this study. The paper first reviews the main factors affecting the shape and characteristic of caved ore mass in sublevel caving and then through the experimental blast testing with cement-sand concrete models, the shape and particle size distribution of caved ore mass were found out. The experimental results indicated that the shape and particle size distribution of caved ore mass was similar to that of the drawn loose body. This finding presented a new perspective for the future study on the ore drawing theory and on the optimisation of structural parameters of sublevel caving. The structural parameters must meet the principle that the shape of the drawn body is in consistency to the shape of caved ore mass.

Jul 11, 2011

The results of about 30 years of exploration and mining activities and research studies in the Kambalda mining district, Western Australia, have led to general agreement that the komatiite-associated Ni sulphide ores formed as a result of igneous processes (Ross, 1974; Ross and Hopkins, 1975; Gresham and Loftus-Hills, 1981; Cowden, 1988; Lesher, 1989 and many others). Despite this agreement, the controls on sulphide supersaturation and concentration of the resulting sulphide in a limited zone, remain uncertain and controversial. A major uncertainty is the source of sulphur in the ore deposits. Two principal sulphur sources have been proposed: 1. komatiite lava/magma (Hudson, 1972; Naldrett, 1973; Lesher et al, 1981; Cowden, 1988; Foster et at, 1995), and 2. sedimentary material (Groves, Barrett and McQueen, 1979; Lesher, Arndt and Groves, 1984; Lesher, 1989; Lesher and Campbell, 1993). Resolution of the uncertainty regarding the sulphur source is required for a complete understanding of the controls on ore formation, which in turn would significantly impact exploration strategies in the Kambalda mining district and elsewhere. This paper reviews the constraints on sulphur sources for the komatiite-associated Ni sulphide ores in the Kambalda mining district. The focus is on the general characteristics of the ores and surrounding rocks: individual ore deposits are not described, though specific examples are noted where appropriate. The stratigraphic and volcanic settings and geochemical (major and trace element and isotopic compositions) characteristics of the ore deposits and surrounding rocks are considered within the context of the competing sulphur source models, and future directions of research in the district are noted.

Jan 1, 1996

By D Craw

Middle and Late Cenozoic fluvial conglomerates and gravel in northeastern Southland record the transport of alluvial gold from Central Otago into Southland, and subsequent reworking and concentration of this gold into economic placer deposits. A corridor of geochemically distinctive, Hg-free gold derived ultimately from veins in Torlesse Terrane schist in Otago extends through the Caples Terrane and into Southland. The initial repository in Southland was fluvial sediment of the East Southland Group, specifically weakly auriferous, quartzose delta plain strata of the Gore Lignite Measures (GLM), a downstream equivalent of Dunstan Formation in Central Otago. Miocene uplift along the northwest trending Old Man Range beheaded the parent river system, isolating GLM from its Central Otago source area and establishing the proto-Waikaia River system. Rising topography between Otago and Southland increased fluvial gradients, and initiated erosion of cover strata and a sequence of tectonically induced gold recycling events. Auriferous GLM were recycled from the hinterland into broad braided fluvial channel and floodplain deposits of the Waikaia Group (new), specifically the highly auriferous Waikaka Quartz Gravels and equivalent Waimumu Quartz Gravels downstream (WQG), superimposing more proximal depositional environments over parts of the former GLM delta plain. WQG were deformed, and locally cannibalised during the later stages of their deposition by reverse movement on north-northeast trending faults of the Dunsdale System (NW side up). Increased tempo of uplift in the hinterland (Old Man, Garvie, Umbrella, and Blue Mountain Ranges) in the Pliocene and early Quaternary resulted in further reworking of GLM and WkQG from the hinterland as well as basement erosion. Progressively more basement-rich detritus was deposited as a locally auriferous piedmont (Gore Piedmont Gravels - GPG) over earlier channel and delta plain (GLM, WQG) strata, extending from the Blue Mountains to Waikaia, and southward through the Gore Gap to beyond Mataura. Southward propagation of the north-northeast trending ranges, local warping, and uplift of the Murihiku Terrane in Pliocene and Quaternary progressively deflected GPG fluvial systems and ultimately constrained them to the present valleys. Pre-existing auriferous strata (GLM, WQG, GPG) were reworked and deposited with or without basement detritus as these fluvial systems migrated toward their present positions. Auriferous remnants of these transitional deposits are preserved in local structural depressions on the uplifted blocks that deflected the systems (eg King Solomon Mine), and on locally abandoned floodplain segments on the lowlands (Pebbly Hills-Gore Gap). The present drainage has continued to incise and cannibalise its own and earlier deposits during late Pleistocene-Recent uplift to form confined channel placers within the present valleys.

Jan 1, 2002

By Oversby B, Wellman P, Wyborn D, McPhie J, MacKenzie D

The Bureau of Mineral Resources (BMR) and the Queensland Mines Department are engaged in integrated regional- and deposit-scale studies in the Burdekin Falls-"Conway" area, about 100km southeast of Charters Towers (Fig. 1). The regional work augments recent mapping in the Mount Coolon area farther south (Hutton et al., in prep.). These studies are aimed at improving understanding of gold mineralisation and its geological setting in the Drurunond Basin and associated rocks. Knowledge of the regional stratigraphic- structural framework and setting of mineralisation has until now been based on investigations dating from the early to mid 1960's (mainly Bowen 1:250 000 Sheet; e.g. Paine et al., 1974; Wyatt et al., 1971), and on regional syntheses (Olgers, 1972; Levingston, 1981). Some recently explored epithermal gold occurrences in the region have been interpreted on the basis of this early work as being hosted by the Late Carboniferous Bulgonunna Volcanics. The objective of our field research was to refine the regional geology, paying particular attention to the Bulgonunna Volcanics. The results summarised here indicate that unnamed Devonian-Carboniferous volcanics (DCv) of the northern Drummond Basin and mid to late Palaeozoic granitoids are much more extensive, and the Bulgonunna Volcanics much less so, than was previously recognised.

Jan 1, 1989

By L McCarthy, B W. Cuffley, O K. Thomas an

The Central Victorian Goldfield is a world-class field located in Victoria, Australia. It is currently undergoing a revival through activities in the Bendigo, Ballarat, Tarnagulla, Maldon, Castlemaine and other fields. Sediment-hosted auriferous gold-quartz reefs that are structurally and geometrically complex dominate the region. To date, no remote methods have been developed to assist in the targeting of the discrete high-grade oreshoots that characterise the mineralisation. An understanding of the structural setting and controls, and thus likely frequency of repetition of oreshoots remains the main exploration tool. Gold within the reefs is generally characterised by both its coarse nature (>100 up to 10 000 microns) and erratic distribution; as a result, most of the Victorian deposits are classed as high- to extreme-nugget effect systems. This characteristic ensures that mineralisation is very challenging to explore, evaluate and exploit. The key issues facing the explorer and miner are related to effective sampling, and definition of geological and grade continuity, and ultimately grade and tonnage. Tonnage can often be estimated to a reasonable level of confidence, whereas the grade estimate generally carries a medium- to high-level of uncertainty. In these deposits, surface diamond drilling alone is generally only able to define an Inferred Mineral Resource, with underground development, closely spaced in-fill drilling and bulk sampling/trial mining required to define Ore Reserves. The extraction of gold from ores is relatively simple, based on the coarse nature and hence amenability to gravity recovery. Ground conditions and the need for in-stope grade control (eg mapping, sampling etc), generally point toward mechanised cut-and-fill as the primary stoping method in the region. To potential investors this style of mineralisation has been viewed as high risk, because of the associated low confidence in the grade estimate, general paucity of Ore Reserves at mining start-up and need for underground development at the Feasibility Stage.

Jan 1, 2004

By B Ekberg, R Salmimies, T Kinnarinen, A HSkkinen

The regeneration of the ceramic filter medium used in iron ore dewatering is often done by combining backwashing, ultrasonic cleaning and chemical regeneration. Of these three, the first two are applied more frequently, whereas chemical regeneration is done only when needed, eg once a day. Chemical regeneration of the ceramic filter medium in iron ore processing can involve the use of oxalic acid to dissolve the iron oxide particles. Even while performing simple chemical regeneration, meaning no ultrasound to assist the cleaning, the changes in the performance and in the structure of the filter medium could not be explained solely based on the dissolution or the removal of particles from the surface. Good regeneration results were obtained at 35 and 50¦C, meaning that the final permeability of the filter medium corresponded to that of unused filter medium. Permeability of the medium after regeneration at 15¦C was also good after 12 h, but did fall short of those regenerated at higher temperatures. Changing the acid concentration did not seem to have a significant effect on the regeneration.CITATION:Salmimies, R, Kinnarinen, T, Ekberg, B and HSkkinen, A, 2013. Particle dissolution in the chemical regeneration of the ceramic filter medium used for magnetite dewatering, in Proceedings Iron Ore 2013 , pp 473-478 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By D R. Carr

The installation of the Flotation Capacity Project flow sheet in the copper concentrator at Mount Isa Mines Limited has recently been completed. The project involved increasing the flotation capacity with Wemco tank cells and Jameson cells as well as changing the copper cleaner circuit layout. The engineering design and construction for the brownfield expansion had significant involvement from operational, maintenance and technical personnel adopting the same approach as the highly successful George Fisher project in the Lead/Zinc Concentrator at MIM. The involvement of people familiar with the concentrator allowed for smooth integration of the changes into an operating concentrator with minimal downtime. Detailed circuit analysis over many years identified opportunities for improvements in the flotation circuit for both grade and recovery. This paper describes the program of work that led to the Copper Concentrator Flotation Capacity Project, and the implementation of the circuit expansion and flow sheet changes that resulted in an overall improvement in the circuit recovery.

Jan 1, 2003

By S Mitra, D O’Dea, N Barrett, S, T Honey, M M. Hoque

The steel industry is currently exploring hydrogen-enriched blast furnace operations as a means to reduce the greenhouse gas emissions. However, there is a need to investigate the gas permeability behaviour of mixed burdens comprising of lump and sinter as the current knowledge regarding their behaviour is limited, particularly with regards to hydrogen enrichment. In the present study, a series of interrupted softening and melting (S&M) under load tests were carried out in a hydrogen rich gas environment (~15 per cent) in the temperature range from 1000 to 1300°C by placing different types of ferrous ore layer including Newman Blend Lump (NBLL), sinter and sinter-NBLL mixed burden in between two coke layers. X-ray computed tomography (CT) was then used to scan the interrupted test samples. Scanned images were first analysed using an image processing workflow implemented in ImageJ and the material simulator GeoDict (v2022) to segment different phases such as coke, ferrous and void based on their grey scale values. A quantitative analysis was then performed on the segmented images to estimate the phase volume fraction as well as bed permeability. Bed void fraction thus obtained agreed well with the bed contraction data obtained from the S&M test. It was further noted that both ferrous layer void fraction and bed permeability decreased linearly with increasing temperature for all ore samples. The mixed burden voidage changed in a similar fashion to the sinter, demonstrating a high temperature interaction between the two materials

Sep 18, 2023

By Wilson A. F

The use of stable isotopic measurements as a technique for elucidating the origin and history of the water in hydrothermal fluids is relatively new. Recent studies have emphasized the importance of meteoric water in the formation of many hydrothermal ore deposits including many epithermal gold-base metal deposits which occur in faulted volcanic terrane. Other vein-type gold ores are be- lieved to have formed from fluids of magmatic or metamorphic origin and exhibit characteri stic 6180 values. These values also give information regarding temperatures and the degree of equilibrium. Preliminary oxygen data for some important gold deposits of eastern Australia are evaluated in the con- text of styles of mineralization.

Jan 1, 1980

By Mackenzie J. M W

The mechanism of clay slime flocculation in coal washing circuits is considered and it is concluded that polymer flocculants are most suitable. It was found that the addition of sea water with a polymer flocculant improved flocculation and settling, and it was also found that dilution of a flocculated pulp increased floc size and hence settling rate.In predicting plant consumption of reagent it was found that cylinder tests, or even pilot plant tests, could give erroneous results, particularly on flocculated pulps. Different flocculants may, however, be compared in cylinder tests.For filtration, flocculation with Separan plus sea water was much more beneficial than flocculation with Separan alone.INTRODUCTIONDuring the mining of coal, and its subsequent beneficiation by washing, large quantities of minus 10 mesh material are produced. This fine material, which consists of broken down shales and fine coal, causes difficulties in water clarification circuits, in refuse disposal, and in filtration of fine coal.These difficulties can be largely overcome by flocculation, and this paper discusses the mechanism of flocculation, the methods by which a selection of flocculant may be made from the large number available, and the limitation of the prediction of plant performance from laboratory tests. This work applies particularly to the washeries of The Broken Hill Proprietary Co. Ltd. (B.H.P.) and Australian Iron and Steel Ltd. (A.I. & S.) .

Jan 1, 1962

By S Youds

The backfilling operation at Olympic Dam mine supports a 9.8 Mtpa underground Long Hole Open Stoping (LHOS) operation. It involves a combination of Cemented Aggregate Fill (CAF), surface rockfill and underground rockfill. The fill material is introduced from the surface via boreholes into the top of the stopes. Due to the deleterious effects of the dust and the thickness of the atmosphere in the stope it is not possible to view the filling process either at optical or infrared (IR) wavelengths. The need for a means to measure the filling process is driven by the placement of both rock and CAF fill in the stopes. The large volumes and high relative cost of CAF makes the minimisation of CAF fill a business priority. Incorrect filling can lead to the sterilisation of ore reserve. The use of millimeter wave radar to view through the haze to give real-time data on the relative positions of the different fill masses is being developed as an in-stope fill monitoring device. This paper reviews the salient points of the technology and its potential use in the backfilling operation at Olympic Dam. The broader potential of this technology for use in the mining industry by æseeingÆ through water and dust laden environments such as that found in stopes and ore passes is also discussed.

Jan 1, 2002

By Hendon G. W, Carr F, Jiang Y

A vast majority of the operating longwall sections use shield-type face supports to provide ground control in the United States. As a co-operative research program between the University of Alabama (UA) and Jim Walter Resources, Inc.(JWR), a joint research program is underway to study interaction of shields with surrounding rock masses. A series of analyses on the response of shields are performed using monitored data at a longwall face in a deep coal mine. In this paper, various effects of parameters, such as leg pressure, setting load, developing load, maximum loading rate, pressure in capsule, and convergence between canopy and base, are discussed and recommended as stability indices. A microcomputer program is being developed for instantaneous interpretation of the shield monitored data, and for giving warnings of potential problems. The preliminary results define the effects of the setting load, developing load, and rate of developing load or leg closure rate. The objective of the study is to understand the shield characteristics and their interaction with surrounding strata in real time, then develop a reliable program for maintaining longwall stability.

Jan 1, 1992

In the 1890s, The Goldfields Water Supply Department in Western Australia commissioned the diamond drilling of two deep artesian exploratory water bores near Coolgardie (Blatchford, 1899). At the time, in spite of strongly-worded advice to the contrary from the Government geologists, there was a wide popular belief that you could obtain artesian groundwater virtually anywhere providing you drilled deep enough. The first Coolgardie hole was drilled to over 900 m, despite the fact that the bore penetrated granite from a depth of 5 m below the surface. Drilling proceeded for more than 16 months, between July 1896 and November 1897. A small quantity of salt water was struck at a depth of 36 m. The second bore was mercifully terminated at a depth of 50 m, also in granite, with again only a small inflow of salt water. Such were the desperate lengths that were pursued to obtain a reliable water supply for the influx of people in the Eastern Goldfields gold rush. The WA Goldfields continued to rely on huge condensers for water supply until that great engineering feat, the construction of a water pipeline from Mundaring Weir to Coolgardie, was completed in 1903. An enormous network of rail tracks penetrated outwards from Kalgoorlie and Coolgardie for the collection of timber, principally to feed the condensers. Remnants of the rail network are still visible today. The acute shortage of fresh water led to great deprivation, disease and death among the early miners. Today, the water problems faced by the mining industry are thankfully not as severe, but they are nevertheless no less challenging. The southern part of the WA Goldfields is a notoriously difficult area for finding potable quality groundwater. Even as recently as the 1990s, there were occasional serious efforts to find potable groundwater in that area, some very imaginative and innovative. One mining company, working south of Southern Cross, spent many months experimenting with recovery of potable quality water from a shallow freshwater lens overlying hypersaline water in a low permeability weathered granite aquifer. They used very low capacity pumps manufactured from car windscreen washer pumps powered by solar panels.

Jan 1, 2000

By Craw D

The Southern Alps in the South Island of New Zealand are currently rising rapidly as a consequence of continental collision along the Pacific-Australian plate boundary. Rapid uplift has resulted in a major thermal anomaly in the shallow crust beneath the alps. Alpine topography and associated intense precipitation, coupled with the thermal anomaly are responsible for vigorous combined topographic/convective circulation of water through the shallow crust.

Jan 1, 1995

By S F. Simmons

At Broadlands-Ohaaki geothermal system, TVZ, mineral distribution patterns in geothermal wells are analogous to those in epithermal veins. Fluid flow through geothermal wells is focused over vertical intervals >500 m with discharge at rates up to 90 l/s. Focused flow at similar rates also occurs in natural systems where hydrothermal eruption vents provide enhanced vertical permeability. These vents are commonly aligned with the tectonic fabric, indicating fault control at depth. We suggest that host rock strength and structural context exert significant control on the hydrological regime conducive to epithermal mineralisation.

Jan 1, 2005

The Beruang Copper-Gold Deposit is located very near the centre of Kalimantan in Indonesia. It is a dacitic tuff hosted deposit currently being explored by Kalimantan Gold Inc of Canada. Exploration activity to date at Beruang has been focused on the Main Zone, which is defined by a north-south elongate, 1 + 1.5 km zone of anomalous copper and gold, and intense phyllic alteration. The disseminated sulfides responsible for the anomalous copper values produce a moderate to high chargeability signature. Phyllic alteration is overlain at high levels, and on the western edge of the Main Zone, by advanced argillic alteration. The dacite tuffs hosting the mineralisation are cut by post-mineralisation dacite dykes that are delineated by ground magnetics and geological mapping. Base metals, principally zinc and lead, form broad halos around the Main Zone. These metals are incorporated in massive NE-trending, polymetallic mineralisation that outcrops to the north and south of the Main Zone. IP survey results highlight the highly pyritic NNE-trending shear zone, which hosts most of the copper mineralisation in the Main Zone. A high chargeability anomaly at depth in the central-east part of the Main Zone is interpreted to be the source for mineralising hydrothermal fluids. This is suggested by zonations in alteration and mineralisation. A deep chargeability anomaly can be correlated with the downward plunge of a pyritic breccia, encountered at shallow levels in drillholes, and is a potential breccia pipe target. Compilation and inversion modelling of the IP results has yielded some interesting drill targets.

Jan 1, 2004

By N C. Steenkamp

The Northern Cape Province of South Africa is host to the Kalahari Manganese Field (KMF). The northern portion of the KMF hosts high-grade manganese referred to as Wessels’ type ore and is mined mostly from underground operations. WorleyParsons TWP is currently involved with the development of a ventilation shaft for one of these mines. The main challenge is to develop through the unconsolidated Kalahari material and weathered portion of the Karoo formation. These formations are preserved very erratically over short distances. A lack of understanding of the unique challenges presented for developing shafts in this area has resulted in the failed development of a shaft on an adjacent property and over-expended budgets on others.The renowned red sand of the Kalahari forms the top several tens of metres and overlies a horizon of gravels and calcrete that pose seasonally variable water ingress problems. A very stiff red clay horizon is then intersected. The Red Clay is prone to swellling during excavation and has been the main stumbling block on previous constructions. The standard approach has been to develop non-stop through this layer. The red clay is underlain by another horizon of calcrete, gravel and conglomerate that marks the bottom of the formation. The top of the Dwyka Tillite (Karoo Formation) is usually highly weathered and has a distinctive yellow colour. The weathered tillite is highly susceptible to drying and becomes friable. At reef-intersection, the combination of subhorizontal bedding and joints with the dominant subvertical faulting results in potential wedge failures in the manganese and ironstone units.This paper describes the geotechnical issues identified during the planning of the ventilation shaft and the risks associated with development through the Kalahari and weathered Karoo Formations. A new approach to developing ventilation shafts in overcoming these challenges is recommended.CITATION:Steenkamp, N C, 2014. Challenges of developing a ventilation shaft in Kalahari and Karoo formations, Northern Cape, South Africa, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 81–88 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014