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The scheme of rehabilitation of surface plant commenced in 1936, included the provision of improved and more hygienic changing and bathing facilities for the employees.At that time the Thompson's Shaft section of the British Mine was being prepared for a resumption of operations, and it was decided to repair and re-equip the existing building. Thus any new scheme adopted could be given a thorough trial, and the proved arrangement used as a basis for the contemplated new main changehouse on the North Section.Investigations were carried out to determine the most suitable arrangement for the Thompson's Shaft changehouse, to provide for a total of 120 men, with particular regard to the internal fittings and fixtures. Also, as the mining conditions were such that a large proportion of clothes worn underground by miners, etc., were wet by the end of the shift, the problem of drying these clothes in the availaole time from a man coming off shift to his commencing again some sixteen hours later was one of the most important to be dealt with.The changehouses in use on the North mine section of the lease were provided with racks around the walls for the men to hang their street clothes on, and a section was partitioned off to house the mine clothes and their drying facilities. The actual drying was carried out by means of hanging the wet clothes over racks between which ran pipe coils heated by means of hot water circulated from the hot water boiler supplying the showers.This method had proved to be far from satisfactory for several reasons, the main objections being:-

Jan 1, 1940

By Hoppe AJ

Drilling and shooting techniques at Moura open-cut have evolved over a period of 16 years and are the result of hard earned experience combined with established practices and consul- tation with professional services. The wide range of overburden types encoun- ted in the field requires varying methods to achieve the best results at all times. Safe working conditions for the employees and protection of mining equipment is of para- mount importance and close liaison is maintain- ed with the Department of Mines Queensland to keep abreast with changing legislation. Drill patterns, charging profiles, types of explosives and ultimate results are des- cribed in detail along with a resume of equip- ment. Costs of drilling, labour and explosives are also analysed with a total of approximately 20c per cubic metre of shot ground. Future developments and improvements to facilities are also outlined.

Jan 1, 1978

By Dimitrakopoulos R

Ore textures in base metal deposits are an important factor in the liberation of the economic components of the ore, metal recovery and reagent consumption during beneficiation. Optimising the mine profit requires knowing the relationship between ore texture and mineral processing behaviour, and the ability to predict the metal grade and the ore texture at a suitable scale. A new method that generates distributions of mesotextures for any mining block size or shape is proposed and includes: I . establishing a protocol for acquiring mesotexture data: 2. measuring the mesotexture spatial correlations using a multi-texture variogram; 3. generating multiple simulations of mesotextures; and 4. upscaling the simulations to generate the expected mining block/stope mesotexture distributions. Models of the ore textures built using the proposed methodology can be used to assess resources and reserves, enhance ore/waste discrimination and predict the metallurgical behaviour of parcels of ore.

Jan 1, 1997

The introduction of large diameter holes to underground mining has provided the first opportunity to apply near spherical charges in production scale blasts instead of the convent- ional long cylindrical charges generally used in stope and pillar mining. A modified version of the cratering prin- ciple was applied in the blast design in extrac- ting ore across a horizontal area of a stope or pillar. The new rock breaking technique has developed into the Vertical Crater Retreat (VCR) mining system and eliminated raise boring, slot cutting and dilution of the ore by back- fill material. Furthermore it has reduced labour and time requirements thus becoming not only a low cost method of mining but the safest method of underground mining known today. Exceptionally fine muck is provided with a minimum of damage by blasts to walls and re- treating backs of the stope or pillar. The VCR method can also be used for drop- raising, and for the excavation of underground cavities for almost any purpose . The proper explanation of the breakage mechanism of the near spherical charges opposite to the cylindrical charges yet to be found. The mining industry has quickly recognis- ed the value of the VCR mining method which is being adopted by an increasing number of mines

Jan 1, 1978

By Pietrobon M. C, Ralston J, Smart St C R

In an on-going study of the chemistry of base metal sulphide flotation, the effect of the inclusion of cyanide in the reagents suite has been studied, with special reference to ore from Pasminco Mining's Elura mine. Cyanide has been variously described as an iron sulphide depressant, a preventor of sphalerite activation and as an activator of galena. In the case described here, the cyanide appeared to act as an enhancer of the galena flotation performance, raising the lead recoveries by 25 per cent but leaving the sphalerite and pyrite responses unaffected. The lead rougher flotation performance with and without cyanide was investigated over a wide range of redox potentials (0 mV to 400 mV SHE). In all cases, the inclusion of the cyanide brought about an increase in the galena recovery and was responsible for a faster rate of galena flotation during the initial stages of the beneficiation. A surface characterisation study (XPS) of the lead flotation stage, with and without cyanide, indicated that the reagent interacted specifically with the galena and pyrite minerals. It was possible to correlate the surface absorption of the cyanide on the lead and iron sulphides with improvements to the flotation performance using the combination of surface spectroscopy and laboratory flotation Testwork.

Jan 1, 1991

The Northwest Territories (NWT) of Canada has emerged as a major new province for diamond mineralisation in less than three years. This is primarily the product of a diligent search in the form of a scientifically based exploration effort. However other factors, including positive aspects of the business and the legal environment have also been identified as assisting the exploration process. In my view these have increased the likelihood of diamond mining becoming a major new industry for Canada. The supportive role of various government agencies has been important. In addition, the character of many of the joint venture deals that have been done has provided an attractive setting for the capital intensive evaluation and development work that is now required to bring the diamond discoveries into production. Perhaps of equal importance is that with the recognition that is being given to the success of the NWT diamond ventures, Canadian explorers are continuing to attract new risk capital for further exploration. This paper attempts to model and quantify the probability of exploration success translating into successful mine development.

Jan 1, 1994

By Edwards R

Greater efficiency of capture of minus 6 mm to fine micron size particles of free gold is achieved with the Knelson Concentrator. The development, principles of operation and recent innovations relating to this enhanced gravity concentrating device are described by the inventor, followed by a description of application and consequent economic benefits in low grade alluvial gold deposits by a large scale user of Knelson Concentrators in the Northern Territory of Australia.

Jan 1, 1990

The risks faced by organisations are part of a risk continuum. They can be evaluated in terms of hazard, uncertainty and opportunity as well as by the degree of influence they have on conformance, operating performance and strategic objectives. This paper discusses the application of risk management techniques for mitigating blasting hazards, reducing blasting output variability, and implementing blast improvement opportunities. Effective risk management practices can identify and evaluate risks across all levels of the continuum and can deliver realistic assessments of the likelihood and impact of risks on the companyÆs safety and business objectives. This paper does not attempt to present technical details about blasting, rather it aims to provide enough blasting context and examples so that the practical benefits of applying the risk management process to blasting can be fully appreciated. The topics discussed include: explosive management plan; statistical process control; quality blasting, rock-on-ground; Blast Management; Mine to Mill optimisation; and blasting information systems. The concept of a blasting risk management system employing a continuous improvement loop is also introduced. On reflection the insights presented should be extremely useful for observing and understanding which risk face has management focus at a mine site or for a blast site.

Jan 1, 2001

By A Thornton, D Engelhardt, J Woodg

Grinding is a critical part of nearly all mineral processing operations. It is the largest consumer of energy on the mine site (and thus indirectly a producer of greenhouse gas through the generation of electrical energy at the power station). Since comminution is one of the main consumers of electrical energy worldwide, efficient control of grinding mills is of paramount importance. Mill Auto-Pilot is a control system developed for SAG mills to stabilise load and power and improve the efficiency of control and increase throughput. A dynamic, mechanistic model of the grinding circuit is used to determine circuit parameters which can not normally be measured using conventional instrumentation. The circuit model is built from models of the unit operations (such as conveyors, SAG mills, cyclones, sumps, etc), and so captures the dynamic complexities and interactions of real circuit operation. CSA Mines at Cobar NSW accepted an offer to be the reference site for Mill Auto-Pilot and the system was installed in March 2004. In this application the model is used to predict mill load mass, mill solids residence time and cyclone underflow density. These parameters are used to control mill load, power and mill discharge density. The outcomes of the introduction of Mill Auto-Pilot at the CSA Mine are discussed.

Jan 1, 2004

By L C. Thompson

Biomineralisation is the process by which microorganisms mediate and catalyse inorganic reactions so as to form new mineral assemblages. The goal of biomineralisation as a remediation tool is to control microbial processes and their environment so as to sequester and immobilise specific toxic metals within exceptionally strong bonds of neo-formed mineral assemblages. In this way, the bound metals are no longer mobile within a geological time-scale. Applied biomineralisation uses microorganisms, which are isolated from a metal waste environment and are selected for their ability to rapidly catalyse neo-mineral development from dissolved or leachable metals. A typical waste environment will contain microbes that contribute to the mobilisation of metal contaminants as well as microbes that possess the potential for remineralising available metals. Selection and augmenting the correct combination of bacteria and eliminating the competing mineral degrading reactions are the key to applying biomineralisation as an in situ remediation process. Applied biomineralisation harnesses the microbesÆ ability to stabilise toxic soluble metals into non-mobile mineralassemblages. This paper will discuss and demonstrate the biomineralisation process through several case studies including the Summitville mine site in Colorado, the McCoy-Cove mine in Nevada, the Argonaut mine in California, and an historic lead site in Crooksville, Ohio.

Jan 1, 2004

By K Hobbs

Mining is experiencing a difficult period of low profitability and declining productivity. To achieve sustainability, mining companies are challenged with improving output, quality and safety while decreasing costs. At the same time, organisations are having to manage a workforce in which individuals no longer accept a traditional style of management, employees prefer more flexible employment, and diversity within teams is becoming the expected norm.Increasing organisational diversity has been shown to have a positive impact on performance and therefore sustainability. Gender diversity and equality between working men and women is the area most studied in this regard. Executives are becoming more aware of the correlation between gender diversity and performance with some larger organisations having dedicated resources to increase the number and status of women in their organisations. Despite this, limited improvement in gender equality is apparent globally over the last decade with some industries, including mining, going backwards. So why is this the case and what other strategies are available?In 2015, the United Nations Women National Committee Australia (UN Women NCA) in conjunction with Autopia released a white paper discussing the lack of visible change in gender equality despite the widespread implementation of merit-based personnel management strategies. Using research from around the world and thoughts from influential government, education and business leaders, the paper ‘Rethinking Merit’ debunks the myth of the meritocracy. It provides a number of recommendations for organisations committed to improving their performance and sustainability through diversity, including a variety of real-life company examples, instead of relying solely on merit-based decision-making.This paper takes the recommendations of ‘Rethinking Merit’ and applies them to the mining industry. It shows the relevance that rethinking merit has for the industry and why applying the recommendations can result in an increase in diversity, therefore enabling greater performance and sustainability of mining companies. This paper provides case studies from Aurizon, Iluka Resources and BHP Billiton and, as a guide for managers, a generic diversity strategy designed to be implemented alongside traditional merit-based personnel management techniques.CITATION:Hobbs, K, 2016. Rethinking merit for a sustainable mining industry, in Proceedings International Mine Management Conference, pp 139-154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By Kilgour I

The installation of a final cleaning column at Ok Tedi Mining Limited was carried out to increase final concentrate grade in order to reduce concentrate handling, shipping and treatment charges and to reduce penalty payments. To fast-track the project a decision was made to install a full-size column on one of the two parallel circuits, designed on information readily available and utilising the experience of mill staff and an engineering consultant, rather than delay installation while a pilot scale program was conducted. A 3.66 m diameter by 12.8 m high column was installed to produce 40 t/h of final concentrate from a combination of rougher concentrate and recleaner concentrate. The column design and sparger system were by Cominco Engineering Services Limited.

Jan 1, 1991

The Ok Tedi Project has been planned as a selective mining operation since the Feasibility Study. The nature of the orebody, and the need to 'stage' the infrastructure buildup meant that initially the mill would process gol ore using a leach-CIP process, followed by parallel leaching of gold ore and flotation of copper ore, and finally all flotation of copper ore. Cutoff grades were applied to gold and copper ore of 1.0-1.3 g/t Au and 0.4-0.3% Tot. Cu. Since startup, unpredicted occurrences of sulphide copper and, to a Lesser extent, carbonaceous material, has necessitated significant additional short term drilling (other than at grade boundaries), and shift grade control in the pit to control contaminant levels. Remodelling of the orebody based on the most up to date variography and geological interpretation has had a significant impact on the reserves, and thus the whole project development strategy; necessitating the earlier processing of copper ores, and preflotation of the gold ore.This paper discusses some of these points in detail, and in particular highlights how unforseen geological occurrences coupled with processing restrictions can have significant impacts on ore reserves and the mine development schedule.

Jan 1, 1986

By P B. Hills, R J. Walton

Narrow vein tabular orebodies are prone to mining induced seismicity. The Tasmania Mine is a complex example of a seismically active tabular orebody, where the contrasting material properties of the host strata and of the orebody itself, serve to exacerbate the seismic response. Analysis of a continuous record of seismicity over a period of seven years has provided significant insight into the fundamental mechanics of the rock mass. Understanding seismicity to permit safe extraction of the orebody has been enhanced by instrumentation of rock mass behaviour in response to mining and mining induced seismicity. It is the purpose of this paper to explore that understanding in respect to the adoption of an alternative down-hole Avoca stoping method for use in particular circumstances.Intensive instrumentation of the Tasmania Mine over a period of four years has provided insight into the behaviour of the rock mass in response to extraction of the narrow vein orebody it encompasses. A range of instruments have been installed in clusters or single installations in order to measure changing stress conditions and the impact of those changes on the rock mass and the reinforcement system.Instruments are often installed in very close proximity to active production stoping. While it has been possible to observe the impact of the mining and mining induced seismicity at very close quarters, instruments installed in these locations are vulnerable to damage and consequently, the level of instrumentation is high. Instruments are continuously logged, typically on a six hourly basis coinciding with the end of regular blasting times. The response of the instrumentation to changed rock mass conditions is considered against the background of development and production blasting and against the seismic record to assess the viability of downhole Avoca stoping.CITATION:Hills, P B and Walton, R J, 2012. Continued observations of rock mass behaviour in response to stoping at the Tasmania mine, Beaconsfield, Tasmania, in Proceedings Narrow Vein Mining 2012 , pp 169-178 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

Hydraulic transport of coal has been used for many years on the West Coast of New Zealand to extract small blocks of steeply dipping coal. Recent development at Strongman 2 Mine has seen the use of high pressure monitors to cut coal and a corresponding increase in the scale of production.This paper provides a brief introduction to hydraulic mining, describes the present system used at Strongman 2 and discusses future potential development.

Jan 1, 1998

By de Lassar de Pressigny Y

IRSID has in its laboratories two experi mental counter-current reduction furnaces allo- wing the simulation of the physico-chemical conditions of reduction in any gas-solid coun- ter-current process, including the blast furnace and direct-reduction shaft-furnaces. The counter current is realized by an electric furnace mo- ving along a laboratory tube filled with the material to be tested. The reducing gas stream in the tube travels in the same direction as the furnace After reduction, twenty samples, with dif- ferent degrees of reduction and which can be related to different levels of an industrial furnace, are taken from the tube and subjected to various quality tests. Experiments were realized to determine the behaviour of various types of industrial pellets when reduced under either blast furnace or shaft furnace conditions. The results show the large influence of the reducing conditions on any pa- rameter characteristic of the quality of the pellets : reduction efficiency, swelling, cru- shing strength and disintegration.

Jan 1, 1974

Western Mining Corporation, managing partner of the Windarra Nickel Project are in- stalling a raise-bored haulage shaft and under- ground crushing system at the Mt. Windarra Nickel Mine. The system will be the second of its type installed by W.M.C., the first being in- stalled at the Otter-Juan mine in Kambalda in 1976/77. Both haulage systems became necessary as a result of the increasing production limi- tations, and escalating costs of a deep decline mine. The Windarra haulage system required a single 3m diameter vertical raise drill hole to a depth of 470 metres. Two five tonne skips in balance will hoist crushed ore and mullock to the surface, at a design rate of 200 tonnes per hour, effectively reducing truck haulage leads by up to 50%. It is expected the project will be in full operation by mid 1982 and will enable the mine to achieve an annual production rate of 600,000 t.p.a. by 1983.

Jan 1, 1982

In order to satisfy environmental and mine operational requirements it is becoming increasingly important to minimise ground blast vibrations at certain locations. These locations are often in soil or on large resonant structures such as grain silos, highway bridges or even the walls of an open pit. A soil monitoring exercise was carried out to evaluate the common practice of coupling vibration detectors to the ground using spikes. At a series of locations in an operating quarry the spiked array response to single blastholes was compared with that of an accelerometer array attached to a calibrated embedded mount. The results clearly showed that the spiked arrays over-estimated the true ground vibration by 46.5 per cent on average, with a maximum observed error of 99.2 per cent. These errors are considered too large for compliance monitoring where accurate vibration levels are required for comparison with prescribed limits. Although spike coupling is convenient, its use for compliance monitoring should be viewed with caution. Unfortunately, however, many manufacturers supply their detectors as spiked arrays. A structural monitoring exercise was also carried out to evaluate the vibration response of a grain silo, highway bridge and a pit wall to the initiation of single blastholes. In this case accelerometers and standard geophones were firmly attached to the bridge which resonated at low frequencies. The results clearly show that, due to their limited low-frequency response, the geophones typically measured only half the true vibration level as measured by the accelerometers.

Jan 1, 1995

The mineralogy of regolith material for which whole rock geochemistry has already been done can be used to better understand/rank the significance of geochemical anomalies. Case studies show that the secondary minerals of the regolith environment have quite different capacities to incorporate pathfinder and target elements, eg hematite appears to be a better host to Pb than goethite and Pb rich alunite-jarosite minerals are a better Ag host than mimetite. Thus correlations between elements in regolith material may be strongly affected by mineralogy. Understanding of the significance of a geochemical anomaly is frequently enhanced by knowledge of the weathering susceptibility of different minerals. For example, when a mineralogical sequence which does not correspond to the expected order is found (eg feldspar overlying weathered material without feldspars) it is possible that transported material is present in the profile. Such mineralogical information is particularly relevant as exploration continues into areas of thick regolith.

Jan 1, 1997

The construction of mine headframes of reinforced concrete is not a new departure as many structures have been built of this, material particularly in Canada and South Africa. This type of construction has been satisfactorily tested in service and is now accepted by the mining fraternity.The two headframes at New Broken Hill Consolidated Limited are the first structures of this type to be built in Australia, and provide an interesting application of reinforced concrete design and construction.Reasons for Adoption of ConcreteDuring 1947 the writer visited D.S.A. and Canada and inspected three headframes, of reinforced concrete construction.Leading details are as follows:(i) Hollinger Gold Mines. (Timmins, Ontario) : Height of sheaves 110 ft. Shaft has provision for 4 skips each of 12,000 lb. capacity. Structure incorporates surface crushing plant.(ii) International Nickel Corporation-Murray Shaft (Sudbury): Height to sheaves 153 ft. 6 in. Shaft provides for 2-12 ton skips and 2 cages. Surface crushing plant built integrally with frame.(iii) Asbestos-Johns Manviae (Quebec): Height of sheaves 116 ft. Shaft provides for 2 skips 200 cu. ft.

Jan 1, 1956