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Rio Tinto has embarked on a journey to use automation to improve the performance of its surface mines. The driver for automation is to improve the accuracy and consistency of mining processes and less to do with cost savings through labour reduction. A key task in most surface mines is blasthole drilling. The degree to how well this is done cascades through the downstream mining process. It impacts scheduling, excavation, slope stability, material handling, beneficiation and final product blending. Improved blasthole drilling was identified as an objective that has a significant business case in most of Rio Tinto's surface mines. This paper describes Rio Tinto's drill enhancement project that has developed a robust system for automating most of the functions on a Terex SKSS16 drill rig. Automated drilling is currently being used in production at the West Angelas iron ore mine in the Pilbara region of Western Australia. A description of the essential elements of the drill automation system is given together with an overview of how automated drilling is performed remotely from the mine office. A review of some of the benefits of the enhanced drill system is given together with the future plans to extend the functionality of the automated drill and the expected benefits.

May 1, 2010

Mr. BRADFORD said :-On assuming this chair, which has been occupied by so many gentlemen of conspicuous ability; my first words must be an expression of the gratitude I feel for the honour you have done me in electing me to be your President for this year.When considering the subject matter of this address to you to-night, quite frankly may it be stated that for a long time I was on the horns of a very great dilemma, for while I could discourse on the modern political trend in relation to our industries at great length, it appeared to me that this was not the place for such a discussion. Next I turned to a consideration of whether a discourse on the theory and practice of iron and steel would be of interest.I, however, banished this idea also from my mind, because it appeared to me that you have already had a surfeit of this on your visits of inspection to our local industries and I did not want in any way to be held responsible for the iron entering into your souls! I therefore propose, with your kind consideration, to address you on other subjects of common and vital interest to all.My first words and thoughts turn on the absolute necessity of eliminating waste in our methods. If we are to succeed in our...

Jan 1, 1926

By G C. Sen

All mining and quarrying operations that employ blasting to fragment and move broken ground have a price to pay for æby-productsÆ such as vibration and noise. These æby-productsÆ cannot be eliminated but they can be controlled and modern blasting techniques have improved to the point that excessive environmental restrictions can be adhered to whilst maintaining acceptable production rates and quality. Accurate measurement is the key to control, and as the environmental limits are becoming tighter, the proper way to measure vibrations from blasting operations becomes an integral part of the mining or quarrying operations. The basic vibration monitoring system consists of a primary sensor connected to a data logger and computer software for the analysis of the signal received and recorded. Currently, as with all fields of measurement, much improvement has occurred over the past decade, and electronic devices are much more accurate and reliable. Data analysis has also improved considerably with the computing power that is available to field operatives today. Mounting the primary sensor has been often overlooked in supposed æstandardsÆ with procedures such as double sided tape, resting on a flat surface provided the vibration level is less than a given amount. But if it is worth going to the expense of the monitoring equipment and manpower, surely it is worth a little extra effort to ensure the primary sensor is coupled to the ground effectively. The primary sensor must move with the ground and measure this movement; so if the primary sensor is allowed to move without respect to the ground (ie poor coupling to the ground) then a false record of the physical event will be measured. This scenario can easily be a practical reality if the primary sensor coupling method to the ground is not effective. In this study a number of mounting methods were fabricated and connected to similar data monitors and a series of ænormalÆ production blasts were used as the vibration source. These mounting devices were measured against an in-house procedure (the æstandardÆ) and the relative merits compared. A laboratory investigation was also carried out to look at the physical parameters of the æsoil and their effect on vibration attenuation of the in-house standard method.

Jan 1, 1999

By T Hughes

Upward pressure on all mining operations is coming from the triple bottom line. To some extent this is being offset by the rise in mineral prices, but this may or may not continue. The other serious issue facing all companies is the replacement of economic reserves as exploration levels over the past decade continued to decline in line with falling mineral prices. In order to underpin the sustainability of the mining industry it is necessary to continue to reduce cost, reduce the mine environmental footprint, whilst increasing community benefit. At the same time it is imperative that we increase the economic reserves. The highest risk is in adding new mineral discoveries as the strike rate for economic discovery decreases. Gekko Systems Pty Ltd recognises that the most simple and risk averse route to increasing economic reserves is to reduce cut-off grade in the mine, thereby bringing formerly uneconomic reserves into the economic category. We have been developing a new process flow sheet which embodies the triple bottom line and the issue of economic replacement of reserves. This paper describes this flow sheet and presents four examples where this concept is/can be applied to bring about triple bottom line benefits. Sustainability can only be assured if we are the ones in control of our environment, costs and reserves.

Jan 1, 2007

The term geochemistry - chcmbtry' of the earth - is almost limitless in its implied subject, but of recent years a major trend of research in this field has been towards economic application in the search for mineral deposits, and in particular for those of some ofthe less common elements for which a demand now exists.Geochemistry is in a state of slow transition from a purely descriptive subject to a fundamental science concerned with the relationships that exist between the distribution of the elements in the earth's crust and the physical characteristics of the atoms of those elements. The progress achieved promises a set of basic principles which will relate the atomic characteristics of an element to the physico-chemical conditions that make for its dispersion or concentration. This means that, given a geological map of an areasufficiently detailed for the physico-chemical conditions existing in past geological eras to be deduced, there is the possibility that the relative distribution throughout that area of any element present, and its likely mode of occurrence, could be predicted from a consideration of its atomic characteristics.Since the atomic characteristics of the elements are becoming increasingly well defined by physical research, the attainment of this ideal of prediction depends upon:(a) the strengthening of geochemical theory; and(b) the development of petrological and mineralogical methods of assessing the conditions of temperature and pressure prevailing in geological formations at various stages in their history.The other prime requirement is a d.etailed geological map - a requirement that is all too often lacking.The fact that there has been very little "geochemical approach" to problems of economic geology in Australia should not be taken to mean that there is little point in trying to develop such an approach here in as active and as rigidly scientific a manner as possible. The degree of success that has attended the attempts so far made, to which reference is made below, suggests the reverse, particularly in view of the relatively slight cost involved if the investigations were properly organised on a centralised basis. There are three aspects of geochemistry that are directly applicable to the search for economic minerals.(a) The classic technique of the prospector can be made more sensitive and reliable by the use of modern equipment coupled with the application of geochemical theory to geological and structural data. The case of the rare alkali elements (see below) is givenhere as an illustration of the way in which the distribution of elements can be predicted from the first principles of geochemistry, thereby replacing the prospector's dependence on his "sixth sense" that enabled him to suggest that a certain area of formation was"favourable" for the occurrence of a certain type of mineral deposit.At its best, this sixth sense amounted to an almost subconscious correlation of all relevant associations and typical occurrences of the particular mineral experienced by the prospector during his...

Jan 1, 1950

By H Aral

A rotating magnetic field can be produced in a magnetic separator by using a magnet rotor fitted with alternate north-south magnetic poles, similar to the rotors currently used in modern eddy current separators. Rotation of the magnetic field causes ferromagnetic particles to rotate during magnetic separation. The particle rotation can then be used simply to remove entrapment during a conventional attraction magnetic separation (RMF lift separation), or it can be used to roll particles away from non-rotating particles, and to move them out of the separator under their own rotation (RMF rotation separation). RMF (rotating magnetic field) separation is a separation for ferromagnetic particles. These particles have a very ordered magnetism that is locked into directions of easy magnetisation in the crystal. As a result, if the external field rotates, the particles attempt to rotate with it. RMF separation uses this fact to rotate the ferromagnetic particles in a rotating field. In contrast, paramagnetic particles have a magnetism that can point in any direction with almost equal ease, and these will not rotate in a rotating field. By making use of this difference in magnetic properties, RMF rotation separation can separate ferromagnetic particles from paramagnetic, even when the particles have similar susceptibilities. Some particles such as both chrome spinel and ilmenite can contain ferromagnetic regions within a paramagnetic matrix. These ferromagnetic regions can vary from very small regions dispersed throughout the crystal, through thin lamellae, to larger more bulky regions. Although most natural ilmenite is ferromagnetic and generally has a higher magnetic susceptibility than paramagnetic chrome spinel, the susceptibility ranges for the two minerals overlap considerably (Allen, 2000a) due to the presence of these ferromagnetic elements, frequently making the conventional magnetic separation of these two minerals impractical. It is known that roasting a mixture of ilmenite and chrome spinel particles increases the magnetic susceptibility of the ilmenite while leaving the spinel susceptibility substantially unchanged. This makes the use of conventional (susceptibility attraction) magnetic separation more practical for the separation of these two minerals. However, very little is known about the effects of roasting on the response of ilmenite and spinel particles to a rotating magnetic field. For example, although the optimal ilmenite roasting conditions for conventional magnetic separation are quite well established such conditions may or may not be optimal for RMF rotation separation. Low intensity conventional magnetic separation on the basis of magnetic susceptibility can be made more accurate if it is carried out in a rotating field, because the rapid spinning of the separating particles prevents the formation of magnetic flocs, and reduces entrapment and entrainment. Medium intensity RMF rotation-only separation (no attraction component) has the ability to separate rotating (ferromagnetic) from non-rotating (paramagnetic) particles, irrespective of their relative magnetic susceptibilities. RMF rotation separation is of particular interest in this case because ilmenite particles generally rotate much better than the mainly paramagnetic chrome spinel particles, and roasting could enhance this difference further. Further information on the use of RMF to separate minerals can be found in Allen (2000a; b and c). The aim of this series of tests on a number of Australian ilmenites was to compare some different oxidising and reducing roast methods and to establish whether the use of RMF rotation separation improves the chrome spinel rejection.

Jan 1, 2001

By Stitt P. H

In Australia, the term "heavy mineral deposits" is used to denote sands which contain variable but economic quantities of the minerals rutile, ilmenite and zircon, often with minor amounts of monazite and xenotime as co-products. Australia has been a significant producer of rutile, ilmenite and zircon from such sands for fifty years and has long been the leading producer of rutile and zircon. The industry had its beginnings with the mining of present day beaches in northern NSW in 1934. Early work was small scale and in some cases involved hand winning of naturally concen- trated mineral for direct export. During World War II and immediately after the industry became increasingly mechanised and by the 1970s on the east coast operated between Newcastle, NSW north to Fraser Island in Queensland. Deposits worked included present day beaches, fossil strand lines up to 5 km or more inland from the present coast and aeolian concentrations. In the mid 1950s, operations commenced on the west coast of WA, south of Perth. Western Australian mineral sands tend to be rich in ilmenite as compared to the east coast. However the WA ilmenites are lower in chrome oxide and make a better syn- thetic rutile feedstock.

Jan 1, 1988

By D Craw, D Falconer

The Morning Star mine is one of numerous historically mined gold-quartz lodes in the Preservation Inlet goldfield of southwest Fiordland. The mine is hosted in Early Ordovician metasedimentary rocks that are composed predominantly of psammitic and pelitic lithologies. These rocks still contain their primary depositional features and are characterised by upper greenschist facies metamorphic grade.   The Morning Star mine lies on the eastern limb of a gently south plunging anticline. A bedding parallel fault-vein and an associated network of minor quartz veins hosts mineralisation. The main fault-vein structure strikes N-NW, dips steeply (~60¦) W, has a strike length of ~350 m, a vertical extent of ~170 m and is up to 2 m in thickness. The internal structure of the fault-vein consists of laminated quartz, massive and fibrous quartz, and silicified breccias/cataclasites. Gold is typically coarse grained (~1 - 2 mm) and associated with pyrite, arsenopyrite, chalcopyrite, tetrahedrite and galena. The geometry of the Morning Star mine is similar in form to that of a saddle reef. Gold-quartz lodes in the Preservation Inlet goldfield are comparable in geometry and host rock to their offset equivalents in the Golden Blocks field of NW Nelson.

Jan 1, 2005

Tougher physical mining and processing conditions as well as economic circumstances are causing many mining companies to re-evaluate the effectiveness of their mine planning. The recent wave of inexpensive computing power provides the engineer an opportunity to go beyond the simple one-off manual mine design and production schedule. The basis of a good mine plan is a good reserves model. Concepts of mine model development are explored. The only advanced computer methods that have found consistent success in optimising mine planning functions are economic pit limits determination and material scheduling. Three pit 'optimisation' methods are examined; the moving cone, the Lerchs-Grossman 3-D graph algorithm, and the new network flow algorithm. A comparison between the methods in terms of total profits generated and computer time involved are made. The results show that both algorithms produced a higher profitability than the simple moving cone, but at much higher execution times. However, the profit increase never exceeded much more than 1 % of the base moving cone case. Finally, a method for the development of long range material production schedules with forward waste planning is presented.

Jan 1, 1989

By Monger N. R

Factors leading to the decision to use Joy Continuous Miners for pillar extraction in the Burwood Colliery are outlined. A detailed description is given of the Joy 1-CM-2 Continuous Miner, including the power supply to the machine, and the method of cutting coalfrom a face. Modifications found necessary in practice are dealt with.The Joy 10 S.C. shuttle car used in conjunction with the Miner, and alterations made to this unit, are then described, together with Ancillary units for the whole installation such as transformers, motor generator set, air compressor,_ cables for power supply and water supply for dust suppression.Special arrangements were necessary to transport the Miner and Shuttle Cars through the tunnel to the Victoria Tunnel seam, and the method of overcoming the transport difficulties is discussed. Manning of the Continuous Miner unit, and final preparation andsubsequent working of the pillars is outlined. Special attention must be given to maintenance of the machines.It is concluded that the combination of Joy Continuous Miner and Shuttle Car is an excellent method for removing pillars in the Burwood Colliery.INTRODUCTIONThis paper deals with the Burwood Colliery in the RH.P. Group in which some units are engaged in the mechanical extraction of pillars with Joy Continuous Miners.In 1941, an amendment to the Coal Mines Regulation Act of N.S.W. forbade the extraction of pillars by mechanical means unless with the express permission of the Minister for Mines. As this permission was not forthcoming, no mechanical extraction of pillars took place in Australia until 1954 As it was doubtful during most of this period whether mechanical extraction would ever come about, coal generally was won with a view to maximum extraction in the first workings, thus giving rise to centre gannon bord panels and 45° angle cut throughs as shown in Fig. 1.

Jan 1, 1957

Some 800 analyses for Cu, Zn, Pb, Ag, Fe, S, CaO, MgO, C02, Si02 and Al203 were used to examine the elemental constitution of the Mount Isa ores, and, for comparison, those of the Northern Leases area.Lead: zinc relations show little order from sample to sample, but means of large zones (Le. individual orebodies) show a highly linear inverse relationship. Lead: silver ratios are fairly constant from sample to sample, and means show a highly linear direct relationship.Sulphide sulphur appears to be related to carbonate and alumina abundance, sulphur decreasing systematically with increase in the ratio CO2:AI203. In all graphs involving members of the group CO2-A203-S the lead-zinc and copper ores conform to the same simple trends, confirming that the two ore types and their host rocks are genetically closely related. The earlier deduction of a volcanic-sedimentary origin for the sulphides of the Black Star orebodies appears compatible with present findings.On the basis of such an origin, the pattern of sulphide occurrence and mineralogy in the Mount Isa district is possibly related to the configuration f the upper surface of the "Eastern Creek Volcanics", the facies patterns of the overlying sedimentary rocks, and to the oldest faults affecting the two.INTRODUCTIONStanton (1962) described and interpreted the chemical constitution of the Black Star No. 2 lead-zinc and the 650750 copper orebodies at Mount Isa. The investigation has now been extended to the other principal orebodies of the area.The earlier study showed that the host rocks of the two adjacent Black Star orebodies were constitutionally closely related, and suggested that this was probably due to their original formation in contiguous zones of sedimentation. On this basis the silica-dolomite of the copper ore appeared to represent the slightly more shoreward, "limey" member, probably a fairly massive algal calcareous sediment laid...

Jan 1, 1963

By D Garcés, M Meléndez, R Castro, E Viera

Enhancing the understanding of gravity flow in caving operations is a key factor in the design, operation and success of caving methods. Consequently, much research has been performed to increase knowledge about gravity flow. Many valuable theories have been gained from different research approaches, which include physical modelling, numerical modelling and a limited number of full-scale tests. Recent advances in technology have allowed Codelco Chile to carry out trials using Smart Markers technology. This technology was used in Esmeralda mine’s Block-2 at El Teniente mine from August 2012 to January 2015. This paper aims to determine the characteristics of the extraction zone and obtain the data that will allow greater understanding of gravity flow for design and draw control purposes.The collected data from recovered markers were analysed using a linear interpolation of both the initial position of the markers and drawbell accumulated drawn tonnage. For each drawpoint in the trial, the regularity or irregularity of flow was analysed based on the recovered markers and the drawn tonnage. Correspondingly, the relationship between flow characteristics and observed fragmentation in drawpoints was analysed. The gravity flow of the Smart Markers revealed that current drawpoint spacing provides the interaction conditions of adjacent flow zones. However, it is possible to increase the drawpoint spacing while allowing caved rock to be extracted from the major and minor apexes.The results of this research also verified that full-scale test data are the predominant factor in the production level design and production control at El Teniente mine.CITATION:Garcés, D, Viera, E, Castro, R and Meléndez, M, 2016. Gravity flow full-scale tests at Esmeralda Mine’s Block-2, El Teniente, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 349–358 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Paiam is a new township in the high mountains of Papua New Guinea built in association with the Porgera Joint Venture mine, one of the world's largest and most remote open cut gold mines. The Paiam town project is an interesting and genuine attempt at building sustainability into a community associated with a mine. A result of a tri-party agreement between a resource developer, government and land owners, this town is a good example of appropriate utilisation of benefits, obtained from resource development, directed at achieving a sustainable environment at local and regional levels.   Mining brought technology and income to the region, although as most mine staff fly directly in and out, local landowners considered there was a limited flow of benefits within the nearby townships. An agreement with government and mine was reached that more mine personnel and their families be housed locally. In 1998, we, a firm of Landscape Architects and Heritage Consultants based in Cairns, Queensland, were engaged to assist develop the fledgling town of Paiam into a livable and sustainable town and to produce material that would convey that information to stakeholders.   The design focused on establishing a sustainable town, with livability, urban form, aesthetics and opportunities for economic, social and cultural development. Aiming to be a livable town for locals and mine staff it included a market place designed as a focus for town life, essential for social cohesion and economic opportunities.   Located at 2200 m on steep rainforest clad topography, the town development has been laid out using an appropriate urban form based on organic village layouts. Clusters of houses allow for a common public area so children's play is monitored assisting with a sense of community similar to a traditional defensible village. Aesthetical consideration helps in developing community pride whilst maximising potential for development of a tourist industry.   Opportunities for ongoing economic development were incorporated in the design and construction process. These included developing skills and trades to service the region and to provide skills, development, income opportunities and infrastructure to last beyond mine closure. Administration procedures were set in place to form the basis of good governance.   The shift from traditional subsistence lifestyle to a sustainable community with traditional attributes was the project's goal and is being achieved.

Jun 1, 2010

By Pullen G, Rose M

Continuing Professional Development (CPD) is not just a catch-cry. It is an essential component of every-day life in many professions, including accountancy, law and public administration. Without realising it, many other professions are undertaking CPD activities in an un-structured way, including mining, metallurgy and geology. Examples include Annual and technical conferences of The Institute, Branch-level technical meetings and in-company training and development programmes and technical exchanges. Whilst approaches to date have undoubtedly helped keep the Australian mining industry at the forefront of mining technology, one cannot presume that technological development will stand still. To meet this challenge, human resource development must keep pace, not only to optimize utilization of technological developments, but more importantly to develop firm bases from which new products, processes and technologies can be developed within Australia.

Jan 1, 1989

Investigation of the Classification Operation in a Coal Pulverising Vertical Spindle Mill Coal pulverisation in power plants is a major electrical energy consumer. In 2006 more than 41 per cent of world electricity generation was from coal where pulverisers use 0.5 to 1 per cent of gross generation. Therefore, pulverisers are an important target for optimisation not only for reducing costs of power generation but also for reduction of greenhouse gas emissions. A better understanding of the operation of pulverisers is an essential requirement for their optimisation. However, little information is available, other than operating experience, on the performance of pulverisers and how these react to changes in operational variables. This study investigates the effect of changes in coal and airflow feed rates on the classification performance that occurs in an industrial scale ball-and-race vertical spindle mill in which the pulverisation and classification processes are linked together due to the separator classifier being an integral component within the pulveriser. In order to decouple the breakage and classification processes, samples were cut from upward flowing streams through sampling ports drilled on the pulveriser body at different locations. Specific sampling tools were developed. Samples collected from the pulveriser were size and density fractioned to distinguish the differences in behaviour of the components, namely coal and mineral matter. The coal flow rates on dry basis within the mill and around the separator classifier were calculated by mass balancing the multi-component data. The difference in classification behaviour of components during pneumatic transport was confirmed. The response of the circulating load in the mill (~600 to ~1100 per cent) as well as the dependency of fineness of the streams to the operating variables was demonstrated. The approach taken in this study has proved that development of a classification model for a vertical spindle mill pulverising non-homogeneous materials, eg coal, requires treating these materials as multi-component/composite substances.

Sep 13, 2010

Ore samples generally require preparation before analysis. Serious problems can occur with contamination degradation and particle size effects. Both grinding element contammation and sample cross contamination havebeen bound to be related to sample hardness and operator technique. For best results with minerals relevant to the steel industry, the use of Siebtechnik-type mills required a combination of careful planning, short grinding periods and intermediate sieving of the sample. The results may be extended to most mineral, rock, and refractory sample preparabons.

Jan 1, 1978

Blasts should be designed so as to maximise the percentage of charges which shoot to a free face (Le, to a pronounced rock/air interface).Free faces should be rough, parallel and reasonably near to blastholes and, very importantly, concavely·biplanar relative to the charges (see Fig. 6b). The presence of biplanar free faces requires that each charge fragments and detaches its quota of the burden rock before the detonation of:1. later-firing adjacent charges in single-row blasts, and2. dependent charges in multi-row blasts.In multi-row blasts, biplanar faces are best achieved:1. by drilling blastholes on equilateral triangular grids,2. by selecting a VI, V2 or V3 initiation sequence, and3. by using down-the-hole delays.Biplanar faces start to be created only when the conventional value of effective blasthole spacing/effective burden distance (Se/Be) increases beyond about 2.4. Values of Se/Be less than about 2.4 result in planar free faces. Where biplanar faces are created, conventional values of Se/Be are invalid and appreciably greater than real values of Se/Be.

Jan 1, 1986

By Hindmarsh J. W, McCoy A. E R

Instantaneous outbursts of coal and gas have occurred at various times in several working districts of Metropolitan Colliery, N.S.W.They have occurred in headings only, under both hand and mechanised conditions, and with seam gas ranging from mainly methane to nearly pure carbon dioxide. A modification of inducer shotfiring using a shear cut was introduced in 1955, and in 1961 full face firing both to a machine cut shear and off the solid was introduced. The current series of outbursts -1961 to 1963 - has been induced under these systems with full control of the time of outburst, but without prediction, and with some disappointing production features.Various aspects of current conditions and practices at Metropolitan are considered singular, such as the coarse granulometry of outburst coal, the prevalence of floor heave, the absence of strong structures at outburst sites, the possibility of outburst at any stage in pillar formation up to the last few yards, the effect of rate of advance on outburst occurrence, and the mildness of many outbursts experienced.It is concluded that inducer shotfiring is a reliable control but it suffers by comparison with outburst-free conditions, and that control by preyention would be preferable.INTRODUCTIONThe phenomenon of instantaneous outbursts of coal and gas has been described in detail previously (Hargraves, 1958). Briefly, it is a combined gas and stress hazard of deep coal mining, usually occurring in virgin work and during active face advance, when coal and seam gas burst from the face into the workings.Instantaneous outbursts have occurred sporadically at Metropolitan Colliery, N.S.W., since 1895. Early outbursts were recorded as firedamp and recent outbursts are of blackdamp.Mining methods used have been conventional hand work, with progressive and relatively complete mechanisation over the past 25 years to substantially conventional...

Jan 1, 1964

By B B. Beamish, J Theiler

Current spontaneous combustion index parameters such as SHT, CPT/RIT and R70 self-heating rate all have deficiencies that need clarifying from a risk management perspective. In some instances they can produce a false negative evaluation and in others they can produce a false positive evaluation. These tests all use a relative rating scheme that does not provide any indication of the time it takes for a spontaneous combustion event to develop, nor do they consider the moderating influence of moisture present in the coal on self-heating rate in the low temperature oxidation region. This is viewed as a major deficiency since the true self-heating behaviour of broken coal is primarily a function of time that is governed by the interaction of the initial boundary conditions (initial ambient temperature and moisture state) with the reactivity of the coal (both intrinsic coal reactivity and accelerated self-heating from reactive pyrite if present). The current index tests are also not appropriate for assessment of coalmine immediate roof and floor rocks.CITATION:Beamish, B B and Theiler, J, 2017. Recognising the deficiencies of current spontaneous combustion propensity index parameters, in Proceedings Australian Mine Vent Conference 2017, pp 113–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

The No. 2 Ore-shaft, at Mount Isa Mines Limited, involving the use of boreholes as ropeways for the upper portion thereof, constitutes, we believe, a unique feature in hoisting installations. The boreholes were sunk from the surface to a depth of 390 ft., thus eliminating the necessity of erecting the hoist at an underground location or construction of the shaft for this distance. Fig. 1, a diagrammatic cross-section through the shaft, shows the complete installation from the surface down to the first loading station below No. 7 haulage level.During the latter part of 1936, conditions encountered in sinking the Main Ore shaft made it impracticable and uneconomical to continue deepening it to serve haulage levels below the present No. 5-level. Plans were therefore made for an interior shaft, to serve new lower levels, that terminated above No. 5-level so that ore hoisted could be drawn off on this level and transported to the Main Ore shaft for final conveyance to the mill crude ore bin.Referring again to Fig. 1, it is apparent that the section above No. 4-level, if opened out to full shaft size, would be inoperative and would serve no useful purpose except, possibly, as a ventilation duct. Original plans therefore did not include continuation of the shaft above No. 4-level. Excavation of a hoist room upon No. 5-level; erection of sheave wheels just below No. 4-level, and a long inclined ropeway leading from the hoist to the sheaves, were incorporated in the general layout. Work on the lower sectionof the shaft had started when the idea of locating the hoist...

Jan 1, 1939