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By Wright G. A

The objective of refining in steelmaking is to reduce the concentration of impurity atoms, e.g. sulphur, phosphorus, from an initially high level to a specified low concentration. A two-film theory of refining is presented in which the rate of

Jan 1, 1980

This paper describes the technical development of the Newman beneficiation plant over its 23 years of operation and how this development relates to the mine ore reserves of high-grade and low-grade ore. It also discusses the importance of the beneficiation product grades in the overall blending of shippable products from a range of mines to optimise overall ore resource utilisation. Also discussed is the importance of the ore reserve reconciliations in resource utilisation. Data is provided on the capacity and quality improvement results of the plant upgrade, carried out in 1999. This shows how the original capacity upgrade targets have been exceeded and the additional quality benefits that have been obtained from this capacity.

Jan 1, 2002

The ores described in this paper are from the two principal orebodies at Wiseman's Creek, a small village about 22 miles south-east of Bathurst in central-western New South Wales.The first official reference to mining at Wiseman's Creek is in "Mineral Statistics of New South Wales" of 1875, which reported that the Wiseman's Creek Copper Mining Company had proved a lode-later known as "North Wiseman's"-to a depth of 120 ft., where it was found to be 20 ft. wide. By 1876 the erection of a mill and smelting works had commenced, and the sulphide ore found to contain copper lead, zinc, silver and gold. Some oxidised ore was also being worked. Operations were, however, generally unsuccessful, and sporadic work up until 1907 produced only about 5,000 tons of ore. The other more important orebody of the locality-the Phoenix-was not opened until about 1895. By 1908, as reported by J. E. Carne, the shaft had been sunk 340 ft., with the extraction of both oxidised and primary ore. At the time of the slump in copper, pric'es in 1907 approximately 3,000 tons of, ore had been produced.Several smaller orebodies were discovered and worked during the same period as the North Wiseman's and Phoenix, but their output was more or less insignficant. THE OREBODIES AND THEIR GEOLOGICAL SETTINGIt is now impossible to examine the orebodies underground, but they appear to have formed a series of flat lenses, whose major axes were parallel to ,the foliation of the enclosing quartz-chlorite-muscovite schists. The largest ,of these lenses was worked as the North Wiseman's orebody, which was reported by Carne to vary in width from 1 ft. to 20 ft., and which probably extended discontinuously over a strike length of about 1,000 ft. The Phoenix orebody is stated to have varied from 1 ft. 6 in. to 3 ft. in width...

Jan 1, 1955

By Wymer DG

The concept of hydro power in deep mines is based on the exploitation of the hydrostatic head that can be gained as refrigerated cooling water descends in shaft pipe columns from the surface, to provide hydraulic power for machines at the working face. This paper describes the work done on two important aspects of the controlled distribu-tion of the high pressure water within a mine, namely the control of pressure under normal operating conditions, and the control of flow in an emergency situation following a pipe breakage. Suitable methods of control have been determined using theoretical techniques to model the steady and unsteady flow behaviour of the water in the pipeline, and taking into consideration the environmental constraints on the types of control devices that can be used. The preferred approach is one in which the high pressure water itself is used as the control medium. The control valves themselves can be fairly conventional in design, but in the case of pipe break protection it is shown that a less conventional approach based on the use of a hydraulic fuse gives improved control performance.

Jan 1, 1985

By Fuller T

This paper introduces the technology used in laser surveying systems, and the development of a reflectorless one-man total station. These systems are being used for applications such as blast pattern surveys, face profiling, muckpile surveys and the general survey of inaccessible areas. Black Diamond Solutions is continuing to assess new technology and develop integrated systems for applications in the mining industry.

Jan 1, 1995

By H Mischo, G Barakos, J Gutzmer

The continuously growing demand for rare earth elements (REEs), in combination with the crisis of 2009 and the price spike of 2011, has initiated a treasure hunt for rare earth deposits all over the world in recent years. Since then, commodity prices have declined and are now quite stable, yet the world is still dependent on China’s dominance of the market and its export policies. Exploration is unremitting and numerous resources of potential interest have already been revealed in many countries; however, proceeding to mining operations is not that simple, especially when it comes to the exploitation of rare earth deposits. Evaluating the feasibility of a mining project is always a unique, sensitive and rather complex process that depends on multiple criteria.This paper focuses on clarifying the present and future global situation in the development of respective deposits and on identifying rare earth-specific criteria that influence the overall feasibility assessments of any potential (especially underground) mining projects. Environmental impacts, legislation issues and the presence of radioactive pollutants are some of the notable boundary conditions that govern rare earth mining operations and need to be taken into consideration. Furthermore, the balance problem between the supply and demand of the different REEs can determine decisively whether a deposit of specific REEs is economically exploitable. For this reason, evaluations are made regarding the future strategies to be enacted in order for the rest of the world to detach itself from this situation. The ultimate goal of these evaluations is for them to be incorporated in an overall assessment tool for rare earth underground mining procedures that will be implemented in real case studies to determine their sustainability.CITATION:Barakos, G, Mischo, H and Gutzmer, J, 2015. Status quo and future evaluations of global rare earth mining (with respect to special rare earth element-industry criteria), in Proceedings Third International Future Mining Conference, pp 21–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By A Sinuhaji, H Kalangi, T B. Setyoko

Ore fragmentation at the DOZ block cave mine is highly variable, both as a function of rock type and column height of draw. Initially, the mine was constructed and equipped with limited capability to handle drawpoint oversize material. Significant issues with drawpoint availability and achieving overall mine production targets resulted. A suite of secondary sizing tools was added to the mine equipment fleet over a one-year time frame. Although significant oversize continues to be experienced, use of the correct secondary breakage tool for each particular oversize or hang-up occurrence has resulted in increased drawpoint availability, production rate, draw compliance, and operator safety. Currently, a range of secondary breakage techniques is being utilised to size material for delivery to the primary crusher. Run-of-mine material (3) is directly mucked to ore passes fitted with grizzlys that have one-metre square openings. Ore containing small boulders (>1 m3, 3) is loader-trammed to ore passes fitted with rockbreakers. Medium-sized boulders (>2 m3) accessible from the drawpoint are drilled with Sandvik Tamrock Commando drills. Boulders hung-up within the drawbell are drilled and charged with a Sandvik Tamrock Secondary Breakage Unit. Compacted, fine-grained muck is blasted utilising 55 mm cartridge powder concussion bombs.

Jan 1, 2005

By Savage E. N

Two genetic types of base metal deposits occur in the Wainivesi area of central eastern Viti Levu. The Wainivesi deposit is now considered to be a stratiform volcanogenic type, and the Wailotu and Wainiviti deposits are described as contact metasomatic with some hydrothermal manifestations. The Wainivesi mineralization is correlated with the Tertiary "e" stage, i.e. uppermost Oligocene-Iowermost Miocene. Tertiary "e" stage rocks in Fiji are therefore potential ore producers of stratiform volcanogenic type. On the basis of plate tectonics with Fiji part of the New Hebrides Arc prior to rifting apart in the late Miocene, stratiform volcanogenic deposits of the Wainivesi type may also occur in rocks of comparable type and age in the New Hebrides.

Jan 1, 1976

By A Roseman, T Gruber

Traditional methods for installing gaskets for segmented bored tunnels have relied upon different bonding procedures with adhesives that carry a series of disadvantages to segment producers. Fixation of the gaskets into the concrete segment as part of the casting procedure has been developed over the last 20 years and has emerged as an economical solution to produce high-quality tunnel segments for various technical tunnel applications. This paper investigates the advantages of using anchored gaskets, the different tunnel systems that employ anchor gaskets and reviews the first anchor gasket project; the Lee Tunnel and analyses how segment production efficiencies are gained.CITATION:Gruber, T and Roseman, A, 2014. Use of anchored gaskets in segmented bored tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 253–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By E Kabwe, M Karakus

Deep hard rock underground mines tend to experience high stress as such drives exhibit dynamic responses attributed to a rock burst variant (strainburst). This dynamic behaviour is difficult to predict, and every effort is made to devise the appropriate dynamic support system for its associated failure restraint. This paper outlines the back analysis and the support scheme design for an underground decline that exhibited damage from a dynamic strainburst occurrence. It employs a decline section that experienced a dynamically loaded strainburst that initiated rock fragment ejections. The procedure involves a preliminary structural analysis, a seismic intensity measure, and a rock mass simulation to determine the static stress concentration and ground support system response. The numerical simulation is conducted in FLAC3D which employs the advanced strain-softening IMASS constitutive model governed by two Hoek–Brown (HB) bounding yield surfaces. To account for the post-peak brittleness response associated with strainburst the plastic strain multiplier () is adjusted to 0.0 < < 1.0. The back-analysis shows that the occurrence was initiated by a low-intensity seismic wave that superimposed an extra stress component to the initial static stress which triggered rock fragment ejections. Additionally, the appropriate support scheme comprised of Weldmesh, Fibrecrete, static (split set) and yieldable (Kinloc) reinforcements is recommended and implemented. Thereafter, the bolt’s efficiency is evaluated based on the axial force and elongation capacities and then compared with the published bolt performance data. The evaluation results show that the maximum bolt axial force (0.1 per cent) and elongation (0.006 per cent) are below the designed capacity and rupture strain.

Nov 29, 2022

With the sinking of the new No. 3 Shaft and the increasing depth and northward movement of the mining operations, improved ventilation of the mine workings became necessary and it was decided to sink a new upcast ventilation shaft midway between No. 2 Shaft and No. 3 Shaft.The shaft is finished to 16 ft. internal diameter and connects with the mine workings at the 2,600-ft. level. It is lined with unreinforced Concrete approximately 12 in. thick. The shaft sinking routine was drilling, blasting and mucking by hand using a 27-cub. ft. capacity bucket. The concrete lining was poured in conjunction with the sinking and was normally finished within 30 to 50 ft. of the shaft bottom.

Jan 1, 1957

By C Katonga

Mindola mine is currently the deepest mine in the Zambian copper belt. Stoping is currently active to 1330 m below surface with long range plans indicating future production from 1590 m level. The orebody is tabular and dips between 55o to vertical. The thickness varies from 8 to 14 m. The vertical crater retreat method of mining was first introduced at Mindola mine in the late-1980s following several trials that helped define the design criteria for its application. Over the last ten years the method has been continually modified to improve safety and maximise ore production. For example, due to the weakness of some rock units within the orebody formation and the instability of the hanging wall, the last VCR slices are usually between 8 - 10 m thick, and efforts are being made to strictly apply shrinkage method in order to reduce dilution. Recent advances in mining technology in the areas of equipment, blasting techniques, rock mechanics and materials handling have been employed to increase the overall productivity of the mine. Large down-the-hole machines capable of drilling 165 mm diameter blast holes, up to 80 m long are used in stoping. Each stope produces up to 20 000 tonnes of ore per month and can last for three months. Heavy systematic ground support of VCR development has significantly enhanced safety for mining crews and equipment. Crater mining has not only improved productivity and enhanced safety, but also overcome various problems associated with conventional sublevel open stoping previously employed at the mine. This paper discusses the technical and operational aspects of vertical crater retreat mining at Mindola mine during the last ten years. The changes in mining method are often accompanied by changes in mine design, blast design, mining equipment, ground support and operating practices.

Jan 1, 2000

The diverse nature of inadvertent mine fires does not lend them to general treatment. But evolving from the unfortunate fires over past years is a simple principle in dealing with all fires to bring combustion under control. Control, in brief, means that the products of combustion, themselves possibly still with fuel values, are not revitalised by addition of fresh air. There are problems with fire- fighting, especially with water, as this may lead to production of CO and H2. Panel ventilation upstream of the fire must be controlled to direct all air over the fire. Some advantages in fire fighting are found by the use of "sails". Early diagnosis of fires and early treatment are essential for safety of personnel and safeguarding and recovery of property. Preparedness extends to up to date documentation, but first hand knowledge also is invaluable to the diverse personnel gathered to fight a fire, and in the decision making Involved.

Jan 1, 1981

By Carter J. P

A two year study into the effects of coal mining induced subsidence on cliff lines was undertaken by the Department of Mineral Resources with the support of a grant under the National Energy Research, Development and Demonstration Program. A new monitoring technique, using an Electronic Distance Meter and acrylic reflectors attached to the cliffs, provided safety for the surveyors and extensive and accurate three dimensional displacement data on the movement of the cliffs as they were being undermined. The study report included many graphs showing the measured vertical and horizontal displacements, differential subsidence, tilts and strains and included analysis of these movements with various parameters, such as, seam thickness, depth of cover and distances between the reflectors, longwall face and the edge of the chain pillar. Some of these graphs are presented in this paper and could be used, with caution, to predict subsidence movements around other cliff lines, after allowing for differences in geology and mining layout. A mechanism is suggested as an explanation for the observed high horizontal movements around the cliff lines. Sixteen percent of the overall lengths of cliffs that were undermined during the monitoring study fell and the contributions of various factors that appeared to influence the cliff falls are discussed. It is concluded that no single factor dominated as the major cause of the cliff falls and, often, many factors combined to cause cliff face instability.

Jan 1, 1992

By E S. Weiss, S P. Harteis

The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) has conducted full-scale explosion experiments, to evaluate the strength characteristics of various seal designs, used for safely isolating worked-out areas in underground coal mines. Large-scale explosion tests conducted within the multiple entry section of PRLÆs Lake Lynn Experimental Mine (LLEM) is currently the only accepted test method used by the Mine Safety and Health Administration (MSHA), for deeming a seal design suitable for use in American mines. These explosion tests are labour intensive, expensive to conduct, and can interfere with other critical underground safety and health research programs conducted by NIOSH. The PRL has developed an alternative seal evaluation method, based on a hydrostatic pressure loading concept, that can facilitate the in situ testing of seals in an operating mine. Two chambers within LLEM and one within PRLÆs Safety Research Coal Mine (SRCM) were used for hydrostatic pressure loading various seal designs. The results from these chamber tests compare favourably with those from the large-scale explosion tests in the multiple entries. In addition to testing seal designs at the required 20 psi static pressure level, the chamber test approach also allows for the determination of the sealÆs ultimate design strength. Size-scaling relationships for predicting the strength of seal designs as a function of entry size are also presented.

Jan 1, 2005

By T Isaksson, J Anderson

The procurement process for underground construction contracts, in particular those contacts involving tunnel boring machines (TBMs), is subject to many complex and inter-related variables, including national and local politics, public policy, community involvement and media attention û as well as strict environmental and legal requirements. Other restrictions include the time available to adequately investigate geotechnical conditions and viable technical options to determine the best construction methodologies û including selection of tunnel boring machine characteristics and, those construction means and methods suitable for the specific geotechnical and environmental conditions. The latter are, most often, quite imperfectly understood. æGetting it rightÆ implies that an optimal configuration û of machine type, characteristics and associated methodologies û can be found and successfully implemented for a particular project. æFrom the beginningÆ implies that the lack of time issue can be successfully resolved. Within an international context this paper highlights a number of issues of concern which relate to tunnel procurement systems and the ways in which certain key processes are managed during planning, design and construction. The authors argue that there is considerable room for improvement in the way tunnelling projects are undertaken and an approach is discussed which has the potential for substantial gains in cost and schedule and reduction of risk. Savings, however, may only be fully realised if the new methods can be fully implemented by all parties involved. This, we believe, will require the rejection of ætraditionalÆ forms of management and procurement with associated changes in the roles and responsibilities of owner, engineer and contractor. Additionally, risk identification, assessment and mitigation are essential cost and schedule control process which have, to this point, been underutilised by the underground construction industry.

Jan 1, 1999

By Nidagal V

This paper discusses the dewatering strategy adopted and the considerations and procedures required to incorporate a dewaterinq scheme into the Mt Whaleback mining operation. It concludes that in pit pre-dewaterinq has successfully allowed mining to progress below the standing water level with the minimum of disruption or radical change to the mining method. It is recognised however, that dewatering is not a static activity and there is a requirement for ongoing investigations and development. Pre-dewatering commenced in October, 1984. Purpose designed pumping trailers have been employed to minimise the loss of pump availability resulting from the frequent. need to remove and reinstall pumps when close vicinity blasts occur. To July, 1986, some 0.5 Mm&apos; of groundwater had been pumped from the unconfined orebody aquifer. Mining has progressed to some 20 m below the standing water level without. any undue water associated problems. Ultimately, it is ,cheduled to extend some 300 in below the original water level in the West Pit. With the development of an increasing area of the mine below the standing water level, the influence of seasonal high intensity rainfall events, which had previously caused little concern, now need to be addressed. Pumping equipment has been designed to evacuate storm water at a rate consistent with mine production Considerations.

Jan 1, 1986

By G Baird, M Seto

A low-cost methodology that allows the determination of in situ stresses using oriented core specimens has been investigated. The technique can be used to determine the stresses during the early stages of a project, even in undeveloped areas of a mine. The research aim was to compare the experimental results estimated by the Acoustic Emission and Deformation Rate Analysis methods with those estimated by conventional Hollow Inclusion cell measurements. The studies have been focused on full stress tensor determination from a single oriented rock core. In all cases the rock core specimens recollected the in situ stresses reasonably well compared with the standard overcoring method.

Jan 1, 2000

By K Biegaj, S C. Dominy

A high-nugget effect and presence of coarse gold characterises many styles of gold mineralisation. The effective sampling of these deposits is often difficult because of the relatively low concentrations involved and erratic nature of the gold or other minerals. Geometric and/or metallurgical complexities often compound this effect. Underground development, in-fill drilling and bulk sampling/trial mining are generally required to delineate Ore Reserves. Similarly expensive definition strategies often apply to surface mining in complex orebodies of gold and other minerals, including precious stones. Development, particularly winzing is a historical technique that was used to gather geological, grade and metallurgical data during underground and near-surface exploration. It permits access to the mineralised structure below the surface datum to determine viability. Winzing has always been considered an arduous and dangerous task. Modern winzing technology has led to the development of the Mobile Supersucker – essentially a giant vacuum cleaner with underground and surface capabilities. By the elimination of shovel-loaded blasted winze material into a kibble and hoisting, this system permits safe and highly efficient winzing activities, and allows the collection of bulk samples for grade and metallurgical evaluation, as well as access to the mineralisation for geological and geotechnical mapping. Bulk samples from horizontal development have long been collected to help define mineable grade via pilot processing. However, when defining blocks below current development, there has been over-reliance on ineffective ‘small sample’ drill data. The Mobile Supersucker permits the development of winzes and off-winze sub-levels. These provide critical information to a mine technical team when trying to justify capital to go deeper or commence or deepen an existing open pit. CITATION: Biegaj, K and Dominy, S C, 2018. Lowering risk in complex mineralisation: application of mobile supersucker development, in Proceedings Complex Orebodies Conference 2018, pp 113–115 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By Erickson M. E, Smith C. K, Carswell J. T

Thirteen holes totalling 3200m were surveyed using a downhole time domain Geonics EM37 system at the 830 metre level within the CSA Mine, Cobar, New South Wales, in order to search for blind, electrically conductive sulphides at some distance from exploration drillholes. A significant off-hole conductor was detected in only one drillhole.Geophysical modelling and interpretation of the survey results indicated that this off-hole conductor was caused by a sulphide lens 30 metres from the drillhole at a hole depth of 220 metres.

Jan 1, 1990