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By Mazandarani M, Chabot L, Vichion K

Pitch-steering models have been developed for discretely advanced mining machines (such as heading machines and coal shearers) using small-angle geometry and there are illustrative examples of simulator predicted performance. Although simple linear models result from the analysis of open-based machines, sledge mounted machines require execution of a Linear Programming energy minimisation to determine the attitude of the machine base at each advance over the previously cut floor steps. An analytical approach is based on elastic beam concepts developed for such applications as longwall face conveyors, caterpillar tracked machines such as continuous miners and longhole drills. Simulation results for longhole drills show the expected performance of an automatic guidance system and the destabilizing effects of sensing deviation too far behind the drill bit. Certain drill bit boundary conditions are expected to assist TBM. steering studies in three dimensions.There is a real role in mining machine steering for the mathematical models used in flight simulators.

Jan 1, 1991

As part of the response to the increased demand for products such as iron ore, coal and gold many resource companies have identified the need to develop strategies focused on attracting high demand professionals and retaining current employees in the business. Recent graduates are entering a time where they can expect high starting salaries, attractive benefits and lifestyle options. At the same time high work expectations and large demands on both personal and professional development will also be the norm. Some of the challenges faced may include high demands on performance, working with limited resources, long hours, and tackling unfamiliar areas of work with little guidance. However, managing your career and these challenges effectively can give you valuable experience in a short amount of time. By offering situations from my relatively short, yet active, career in the mining industry during these boom times I will raise some key points on how to best leverage your commodity and make the most of a bullish market.

Jan 1, 2006

By M Rauer

With a worldwide growing population the demand for higher living standards, food and the development of new technology is rapidly rising. To allow for a continuous growth, larger quantities of minerals and raw materials are needed at a faster pace. Different methods have been developed to access or tap ore more quickly, such as improved drill and blast operations, mechanical mining methods using equipment such as roadheaders (RH), longwall miners and other technical equipment. Another possibility to access and develop mines faster is the use of a tunnel boring machine (TBM).The historical usage of TBMs is surprisingly long, but the opportunity for technology adoption by the majority of worldwide mining companies remains largely untapped. Dozens of full face TBMs have been used by mines around the world, including two that will begin operation soon in Australia. TBMs have been used to safely and rapidly gain access to the orebody, or to expand access to the orebody to increase output by running a TBM along the edge of the orebody for several kilometres. These machines have also been used for ventilation and for conveyor tunnels for ore removal. They have been used to quickly excavate long and winding declines giving access to an orebody at several levels in a short period of time.Tunnel boring technology can be used for mine declines, mine access tunnels and all sorts of different mine designs and set-ups. TBM technology simply needs to be adapted to the mine conditions and, if manufacturers are involved early on in the planning process for mine development, the operation can be very successful. In some cases, historically typical mine designs may need to be re-thought.One mine, the Stillwater Platinum mine in Nye, Montana, is currently employing its fourth TBM in 25 years. Two were used to create tunnels running alongside the orebody, rapidly expanding access to the orebody in many locations for increased output. Two were used to create parallel access tunnels to a mine expansion at the East Boulder orebody; one tunnel is for conveyor haulage and the other for vehicular access. TBMs have been employed successfully many times to rapidly drive vehicular decline tunnels to multiple mine levels, such as at the San Manuel – Magma Copper mine in the USA. While TBM technology may not seem to be optimal for every mine, these success stories show that the method can provide vast benefits for the right projects.Early use of TBMs in extremely hard rock metal mines, in the 1960s and 1970s, had limited success since performance was low. However there have been great improvements made over the years in the strength of rock which can be excavated by TBMs with high performance. Other important improvements involve the provision of a safe work environment, safely and rapidly supporting the rock and predicting geology ahead of the TBM.This paper will briefly note the more than 20 TBM mining projects and highlight some notable successes. It will then go on to give a status report on the two active TBM mining projects in Australia and the difference between a TBM operation versus other excavation methods such as drill and blast (D&B) or RH excavation.CITATION:Rauer, M, 2014. Tunnel boring machines in mines – a?brief review of past use with a status report on use today in Australia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 663–670 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By A L. Bennett

It is well understood that designers and constructors must protect the existing surroundings of tunnel construction, particularly in the selection of excavation methods, ground support and waterproofing systems. However, while this can readily address the existing conditions, the tunnel owner and the designers need to consider the changes that are likely to occur during the life of the tunnel. It is typical for transport infrastructure to have a design life of at least a century. While the effects of constructing the tunnel on its surroundings are a short-term effect, the converse case, the protection of the tunnel, and the need to maintain its integrity, will affect developments over and adjacent to the tunnels beyond the foreseeable future. Decisions made during the design phase have the potential either to facilitate development or to hinder it for the long term.Examples principally from Australia, New Zealand, Singapore and Hong Kong show that the provision for future development is addressed in different ways. These have ranged from making no specific provision, putting the onus onto developers to ensure that the tunnels are not affected adversely, to including a loading allowance for future development in the performance specification or contract documents for a tunnel project.These two contrasting approaches have strong points and risks. A highly prescriptive definition of permissible loadings around the tunnel can provide unambiguous guidance for the approving authority and the developer, but runs the risk of being overly conservative to allow for all the envisaged works, while still missing a detrimental combination of effects that theoretically complies with the specified requirements. In contrast, a general requirement to not cause detriment is open to interpretation and potentially difficult negotiations to reach agreement between the tunnel owner/operator and developer and finally the appointed contractor (probably with no contractual relationship with the tunnel owner).In practice, a combination of prescriptive and performance requirements is likely to provide the optimum combination of clarity and flexibility. The author provides examples and recommendations on how such provisions could be structured.CITATION:Bennett, A L, 2014. Protection of ?tunnels in their future environment, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 495–500 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Upgrading of Indonesia's Bauxite by Washing Method There were eight bauxite samples used in this research, three samples from Kijang contain total SiO2 18.36 - 29.16 per cent, Al2O3 40.12 - 48.36 per cent, Fe2O3 4.27 - 5.13 per cent, one sample from Tayan, contains total SiO2 4.69 per cent, Al2O3 38.95 per cent, and Fe2O3 19.67 per cent, and four samples from Mempawah contain total SiO2 33.5 - 44.8 per cent, Al2O3 29.8 - 35.9 per cent, Fe2O3 7.29 - 9.88 per cent. All of those bauxite ores have not fulfilled the requirement for Bayer process yet; therefore simple up-grading using a rotary drum scrubber is needed. The scrubbing process was carried out with time variable up to 60 minutes with solid percentage applied was 50 per cent and rotary speed was set up 30 rev/min. The bauxite was washed by following steps: scrubbing, screening, drying, and finally it was analysed to show chemical content. The washed bauxite produced has size fraction that is retained on the 1.7 mm of screen opening. The result of the research shows that the higher alumina content of the raw bauxite, the longer washing time is needed moreover the higher quality of the washed bauxite is produced. The highest alumina content of the washed bauxite was 53.67 per cent with the alumina recovery was 89.66 per cent and the concentration ratio of 84.80 per cent was achieved within 20 minutes of washing time of the raw bauxite (Al2O3 48.36 per cent). The washed bauxite resulted from this research is suitable as a raw material for Bayer process.

Sep 13, 2010

By Faidel VV, Yushina TI, Yagodkina NG, Yatsimirsky AK, Chanturiya VA

Among the problems of the flotation of sulphides by the thiol collectors is the dependence and varieties of the flotation starting with the time and oxygen contents in the slurry. For sulphides, the flotation stage follows after the electrocatalytic oxidation of the collector with oxygen on the surface of the conductor minerals. The necessity of the oxygen for sulphide flotation (Plaksin and Bessonov, 1957) is in accordance with a corrosion model of a collector surface sorption (Salamy and Nixon, 1954). As Golikov and Nagimyak (1961) showed, the sulphides possess catalytic activity which provides the autoxidation of the xanthates in the sluny to the dixanthogen. This stage can be rather protracted, which limits the speed of the total process. Disulphides constitute important collectors for the sulphide flotation and the optimal degree of the xanthate oxidation is about 20 per cent for different ores (Abramov, 1978) or, following Chanturiya and Nazarova (1977) the surface compositions for various sulphide ores are different and an optimal oxidation degree is variable from five to 25 per cent according to the ore nature. The optimisation of the surface composition is possible by application of the dixanthogens, or by a partial chemical, electrochemical, or catalytic oxidation of xanthates (Desains, 1847; Schall, 1896; Vigdergauz, 1989). According to Rand (1977) and Vigdergauz (1991) sulphides possess different catalytic activities for oxygen electroreduction. In neutral solutions, for example, the following decrease in the order: FeS2 (Fe,Ni)9S8 CuFeS2 FeS; Cu5FeS4 Cu2S; PbS (Vigdergauz, 1991). For the cases of low catalytic activities of the sulphides, the preflotation oxidation of xanthate could be useful to optimise the process kinetics.

Jan 1, 1993

By B Besa, E K. Chanda

It has long been recognised that narrow vein mining needs innovative approaches to mine access and mining methods in order to improve the economics of this vital part of the mining industry. The mining equipment used currently requires large openings in narrow vein-type deposits making mining operations uneconomical. In view of this and other shortcomings of the current mining practices, a study was initiated to investigate the potential of using low profile electric loader with mounted conveyor in conjunction with the electric monorail haulage system (EMTS) to load and haul the blasted material, particularly in decline development and main haulages. Computer simulation based on the General Purpose Simulation System/Henrikson (GPSS/H) is used to model the system and evaluate its performance. The results are compared with those for conventional mining using trucks and loaders. The EMTS provides competitive haulage rates in substantially smaller excavations than is currently achievable. According to simulation results, the electric loader in conjunction with the EMTS had the same number of blasts as the conventional system and hence the same advance rate of 3.33 m per 12 hour shift. Furthermore, the total drill-blast-load-haul cycle time was less than the conventional system by one hour.CITATION:Besa, B and Chanda, E K, 2012. Evaluation of low profile electric loader in conjunction with electric monorail haulage system in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 221-228 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By J Hadjigeorgiou

Narrow vein mining, as most types of mining, faces important geotechnical challenges. The specificity of geotechnical challenges in narrow vein mines stems from the nature of the deposits, which are often inclined, discordant and found within fractured rock or faults or in shear zones within country rock. This complicates the construction of representative geomechanical models and limits the applicability of several engineering design tools. Furthermore, in certain cases, the severity of encountered geotechnical problems is considerably greater in narrow vein than in wider orebodies. This paper provides an overview of geotechnical and other challenges in narrow vein mines with a focus on how these are currently addressed. Of particular concern is the use of manual labour working close to the mining face where there is greater exposure to geomechanical hazards. This review concludes with a particular emphasis on understanding the limitations of commonly used engineering tools and techniques to address geotechnical problems in narrow vein mines.CITATION:Hadjigeorgiou, J, 2012. Geotechnical challenges in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By J M. Wallis

Heavy mineral sand exploration drilling prior to the 1970s generally utilised open hole auger and air-blast type drilling. However, mining reconciliations were poor and limitations on accuracy and precision of drilling results were severe.Working with the exploration companies, Wallis Drilling principals designed various systems, including what was termed the ‘Eneabba System’ and then the ‘Capel Twin-Tube System’. Eventually the company with its improvements developed and patented the Aircore Drilling System.Aircore drilling has subsequently become recognised as an excellent drilling system for exploration and mine-sample drilling that gives good precision and accuracy in sampling both above and below water. Its use has also been extended to many other commodities and is used in a number of overseas countries.This paper documents anecdotally the development of the system, identifying problems encountered during the times it was evolving and of the means to overcome the problems as being the documentation of the story by the inventors and developers in Wallis Drilling Company. Aircore drilling system is a Western Australian technological development owing its existence to the designing and incorporation of a number of discrete improvements along the way and recognises the tenacity and inventiveness of all who contributed to the system, in both Wallis and also in a number of companies that gave the impetus to succeed.

Oct 5, 2011

By Boyd GL

Backfill applied to highwall mining is foreseen as a means to increase recovery of mineable coal to levels comparable with underground longwall mining. This paper describes the progress of research to demonstrate the role required of backfill to achieve real increases in coal rCCOvCrCd h\ hi'eh ss-all mining methods.

Jan 1, 1998

By Larke R, Warnock J

Although Western Mining Corporation has been producing high grade nickel ore at Kambalda since 1967, it has only recently become a significant gold producer.The main source of Gold ore has been the Victory Gold Mine located 17 kilometres South of Kambalda.This mine produced small tonnages of high grade gold ore from a sediment horizon within a complex sequence of mafic flows, in the 1890's, early 1900's and 1930's.Today, mining is centred around 2 com-pletely different ore bodies named Victory and Defiance, and involves several different mining methods. This paper describes the Operation's history and gives an outline of the proposed stoping methods.

Jan 1, 1984

By Moxon N. T

The detonation pressure of ANFO can be significantly reduced by the addition of low density materials such as polystyrene, bagasse, swadust or perlite. Laboratory and field test results have shown that homogene- ous mixtures of these low density explosives can be produced in a bowl truck and loaded into a blasthole without segregation. The detonation pressure of the mixture can be altered to be more compatible with the material in which it is being used by varying the quantity of low density additive incorporated into the mixture. Field results have shown that these low density explosives can lead to significant cost savings without com- promising fragmentation or production.

Jan 1, 1989

An automatic control system of a longwall roof support is dis-cussed. Hydraulic automatic control systems for longwall roof support have not met all requirements for such systems. Utilization of standard hydraulic elements to form a system that would-comply with all demands leads to a very complicated structure with a large number of hydraulic hoses within and between adjacent supports. So, only simplified systems have been made. This paper describes the multifunctional valve that per-mits realization of any desired logic functions, while maintaining a com-pact form, and analyses its application as a fully hydraulic automatic control system of a roof support.

Jan 1, 1985

By A Black, A de Jo, J Cavanagh, J Harding

Acidic and metal-rich waters have been discharging from Sullivan Mine, West Coast, New Zealand since the closure of the mine during the early- 1990s. This has resulted in a decrease in pH from a background of 4.5 to 2.8 and an increase in metallic elements in nearby Rapid Stream. In addition to the chemical effects on Rapid Stream, a study of freshwater macro-invertebrates revealed the absence of most biota downstream from the discharge. An attempt is being made to use the Sullivan Mine as a case study of problem and remediation analysis.

Jan 1, 2003

By K Peters, C McKenzie

New Zealand has an established history of gold production beginning with the gold rushes of the 19th century in the Coromandel, Nelson/Marlborough, West Coast and Otago regions. Despite this, the number of significant modern hard rock gold operations has been limited in recent years due to a lack of sustained exploration capital and not limited geological prospectivity.The New Zealand Government is actively encouraging explorers to invest in New Zealand through a series of targeted promotional visits, more importantly through the acquisition of precompetitive regional geophysical data. Data collection has been completed over the prospective Northland epithermal district and a large portion of the South IslandÆs west coast that is prospective for both orogenic gold and intrusive related gold.Analysis of new data has been an important component in aiding the generation of exploration targets from prospectivity modelling. Determining the prospectivity of an area involves reviewing all the available data and analysing it with respect to the most up-to-date mineral system model for the mineralisation style of interest. Using the weights of evidence modelling approach, the most prospective areas for epithermal gold-silver, orogenic gold and intrusion-related gold have been identified. The key exploration parameters relevant to each mineral system are first represented spatially and then statistically combined into a single prospectivity map. New potentially economic deposits could be found by focusing exploration on targets identified from these models. The prospectivity modelling approach can greatly reduce the risk involved in mineral exploration.CITATION:Peters, K and McKenzie, C, 2013. New Zealand gold potential - using mineral prospectivity modelling to evaluate gold-bearing mineral systems in an underexplored country, in Proceedings World Gold 2013 , pp 479-486 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

The Division of Minerals and Geochemistry in collaboration with three mineral exploration companies, Mawson Pacific Ltd, Ramsgate Resources Ltd and Tectonic Systems Pty Ltd commenced a two year research project to investigate the application of remote sensing techniques to exploration for mineral deposits in access of the Yilgarn Block in Western Australia. The project utilizes satellite data such as day and night imagery from the NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) satellite. The recent research with the imagery in the Kalgoorlie, Southern Cross and Mt Magnet regions has highlighted the advantages of the mid infra-red and the two thermal response channels of NOAA-AVHRR for geological investigations. These three channels have the spectral resolution to distinguish stratigraphic units and younger intrusive bodies, and to delineate fracture zones and shear zones associated with Proterozoic dykes. But most important is the capacity to distinguish thermal signatures from geological structure, near-surface outcrop and palaeochannels which have been covered by unconsolidated sediments. The research project applies remote sensing methods including enhanced satellite imagery optimised to the Western Australian environment. It encompasses data from both space and airborne monitoring platforms that have obsreved a significant spectral response for the classification of alteration zone lithologies. It includes the collection of multiseasonal data from areas of interest which is essential both for the understanding of thermal characteristics of important lithologies and for the extrapolation from field work investigation to potential exploration areas. No comprehensive investigation of this type has been carried out within the Yilgarn goldfields.

Jan 1, 1987

Since gold was first discovered, mining development in the West Australian goldfields has been heavily dependent on the location of groundwater both for potable and mineral processing supplies . The location of adequate and economic sources of water has been a constant challenge to both explorers and developers throughout the history of the goldfields. The provision of a piped supply from Mundaring in 1903 greatly alleviated pressure on scarce resources, lowered mining costs and permitted the orderly development of infrastructure. However, increases in the demand for water resulting from new mineral discoveries over the past three decades has led to renewed pressures for more local supplies to be established. Wide-ranging groundwater exploration took place in the late 1960's and early 1970's, also, more recently, in support of intensified gold exploration. The collation and interpretation of the hydrogeological data from the whole goldfields region indicates that despite a low mean annual rainfall of between 180 and 350 mm, quite marked differences exist between the rates of groundwater recharge in different parts of the area, In general, these can be shown to diminish in a southerly direction contrary to a trend towards increases in annual rainfall. Recharge rates are related mainly to differences in rock weathering pattern, geological structure and physiography. The same differences have controlled the pattern of groundwater salinity and the magnitude of groundwater storages associated with the palaeodrainages. In the vicinity of the northern and western watersheds with the Gascoyne, the superficial sediments tend to be thin, may have calcrete in the section and contain moderate storages of brackish or even fresh water. This contrasts with the lower regions of the palaeodrainages where calcrete is absent and deeper erosion has permitted the accumulation of relatively large thicknesses of fine-grained sediments which are saturated with hypersaline water and constitute substantial storages. Account must be taken of these characteristics if water supply sources are to be optimised to meet the growing demands for groundwater in the region.

Jan 1, 1988

By I Jabouri

There are many physical factors that can affect the self-heating rate of coal. The presence of seam gas has often been referred to as inhibiting coal self-heating due to the limited access of oxidation sites created by the presence of the gas adsorbed on the coal pores. Similarly, the presence of bed moisture in the coal also acts as an inhibitor of oxidation by blocking access of air into the pores. Gas drainage of a coal seam prior to mining removes both gas and moisture from the seam. Bulk coal self-heating tests in a two-metre column on both gassy, as-mined and gas-drained, dried high volatile bituminous coal show that removal of gas and moisture from the coal accelerates the rate of self-heating to thermal runaway from 8.5 days to 4.25 days, from a start temperature of 30¦C, with an airflow of 0.25 L/min. The corresponding gas evolution pattern for each of these situations is different. Therefore, it is necessary to take this change in coal condition into consideration when developing a spontaneous combustion management plan.

Jan 1, 2005

By Morsky P, Kalapudas R, Natunen H, Virtanen M

The development of autogenous grinding modification in Outokumpu, known with the name 'Outogenius Comminution', was 'reversed'. At first the metallurgists studied and tested tens of years autogenous grinding in detail in full scale circuits at the concentrators of the company. After the final solution already had been found, also a pilot plant was built and now finally, research work is under way to develop a special laboratory method for testing the suitability of ores for 'Outogenius Comminution'.

Jan 1, 1993

By Savidis G

The characteristics of 'Z' (Back-over run) and 'R' (Reverse) ventilation systems are dis- cussed in relation to their suitability for longwall mining. Experience in European mines has been described as a basis for comparison with Australian conditions. In assessing the merits of each ventilat- ion system, such factors as longwall layout (pillar design, number of headings and gateroad stability), the need for gas drainage and bleed- er systems, as well as the influence of seam dip have been considered relevant. The R system is generally applicable for single and two heading development in seams where gas emission is a less serious problem. In contrast, the lower extraction to development ratio of the Z system (which arises from using three or more heading layouts) is considered more favourable where high gas emission occurs. The Z system provides greater flexibility with respect to the provision of refreshing air at the tailgate end, access of men and materials, installation and retrieval of gas drainage systems and the ability to interchange main- gate and tailgate roadways in cases where roof strata loads are difficult to control, or where cpam in hac an influrnra

Jan 1, 1983