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By Recepoglu O, Tolun R, Yavasoglu N, Bulutcu AN

Scheelite was floated from a low-grade (0.28 per cent W03) calcitic (96.30 per cent CaCO3) scheelite ore using oleoyl sarcosine as collector and alkylated 8-hydroxyquinoline as modifier. Compared to oleoyl sarcosine alone, the grade and the recovery of scheelite concentrate were increased from 8.07 per cent to 33.54 per cent and from 55.1 per cent to 73.4 per cent, respectively. Infrared studies with pure calcite and scheelite minerals showed that while alkyl oxine is adsorbed on the scheelite surface, it is not adsorbed on the calcite.

Jan 1, 1993

By G W. Wilson

Net solar radiation is one of the key factors affecting evaporation from soil covers on waste rock dumps. While net solar radiation is normally taken as a uniform parameter over a site for modelling purposes, there can be significant variation in the radiation actually received on various portions of the dump. These variations are a function of the difference in the cover slope and direction of exposure. A predictive model has been developed to calculate the actual radiation received on the dump surfaces, based on the net radiation data measured at a weather station on a horizontal surface. The model has been designed for application at any mine site in the world, and can be used in conjunction with evaporative flux models to help estimate the effect of three-dimensional variations in the cover surface exposure. The waste rock dump at Equity Silver site (located in British Columbia, Canada) has a barrier-type soil cover system to limit oxygen entry and water infiltration. This cover has been monitored for the past nine years. The new net solar radiation model has been applied to this site and the predicted net radiation was compared to the values of actual net radiation measured on the site. The predicted variations in net radiation over the three-dimensional surface of the waste rock dump have been applied to calculate spatial variations in potential and actual evaporation (or evapotranspiration) from the site. Preliminary analyses indicate actual evaporation from a site at this latitude could vary by a factor of two for exposed versus shaded slopes. The implications of these variations for the site are considered.

Jan 1, 2003

In classical drill and blast underground mining methods, especially narrow vein operations economic quantities of broken ore can be left behind following normal mucking operations on the stope floors. The ore left behind can have significant economic value and if not collected can be lost forever. This paper reviews techniques for cleaning this material from stopes that have been used in the past and reviews possible modern techniques that can be applied to ensure this valuable material is removed from the stopes.

Aug 1, 2010

From the viewpoint of mechanical efficiency, charges should be fully coupled and, upon detonation, should just fail to break the rock in compression. But because mining thrives on its cost-effectiveness rather than its mechan- ical efficiency, the explosive which generates maximum energy per $ should generally be used, even though the mechanical efficiency of this explosive's detonation products may be sub- optimum. Wherever possible, each charge should have a length:diameter ratio of about 20 or more and should shoot to a concavely biplanar free face that is both parallel and reasonably close to the blasthole. Success in obtaining parallel effective faces often demands the drilling of angled blastholes and, hence, will require intensified research and development efforts by drilling manufacturers, especially where hard strong rocks are encountered. Blastholes should be drilled on equilateral triangular grids and fired in a Vl or shallower V-type sequence using inter-row delays which ensure that good pro- gressive relief of burden is achieved. The conventional method of calculating Se/Be values (on the basis of planar effective faces) is often invalid.

Jan 1, 1986

By Letz H

An investigation of earthquake hazard in Papua New Guinea (PNG) by a yearly extreme magnitude method using the magnitude 7 earthquake record since 1900 shows that the Bougain-ville Island seismic zone is by far the most active, followed by the New Britain and northern mainland PNG regions. Return period for magnitude 7.0 earthquakes occurring in normalized 10,000km2 areas of the Bougainville Island, New Britain, Huon, West Bismarck, North Sepik and Ramu seismic zones is 37, 60, 81, 88, 125 and 125 years respectively. These areas are much more active than the California Seismic Zone 4 region including the San Andreas Fault, which has a normalized magnitude 7.0 return period of 299 years, calcul-ated here by the same method.Only southern PNG, including the Papuan Fold Belt and most of the Bismarck Sea, are less active than California Zone 4. The Papuan Fold Belt is only marginally less active than California Zone 4, but more active than the State of California taken as a whole.

Jan 1, 1994

This is the time of year tor the presidential address, and with the present incumbent engaged in the coal mining industry, it will therefore come as no surprise to you that the theme of my address this evening is concerned with coal.There are other reasons for this apart from my contact with the coal industry. At present, coal is supplying considerable overseas revenue at a time when the remainder of the mining market is in a somewhat depressed state. That times will change goes without saying, if history is to be believed.However, so far so good for coal. My first reaction when The Institute indicated its wish that I be president for 1976 was to become deeply conscious of the honour bestowed on me.On consideration, I realized that very few past presidents have been intimately connected with the coal mining industry to the extent of indulging in it for lengthy periods as a full time occupation or, conversely, a part time interest for a long time. It also appears that not one had started their career in the industry. In my case, 'also, there were 8 very interesting years ,as a gold miner and metallurgist before commencing in coal.It therefore seemed appropriate to endeavour to discover ,why this should be so, as coal mining is now a very important part of a very important industry. What were the reasons why the industry took so long to emerge when there were ample reserves of easily accessible coal?Frankie and Johnnie in their bar room epic of the depression years concluded, and I paraphrase, that "their story held no moral, their story told no tale". If my story has such a message, it could perhapsbe construed as reinforcing the oft-repeated dictums, true or false, that "history repeats itself" or "man never learns".Coal mining is by far our oldest major Australian industry except for agriculture. Its history is almost as old as that of settlement:For various reasons, there has been a glamour associated with metal mining ventures which prob...

Jan 1, 1976

By B Poborowski, A Chen

"For some time, the Australian and Chinese underground coal mining industries have evolvedindependently with minimal infl uence on each other. Despite the fact that in recent years severaltechnologies and solutions have become common to both industries, this trend has seeminglycontinued to the point that there are still many important diff erences in legislation and hazardmanagement systems in both countries. Austar Coal Mine as an Australian based and Chineseowned enterprise has a unique opportunity to benefi t from the technology and knowledge ofboth nations. This paper compares the Australian and Chinese approach towards spontaneouscombustion hazard management in order to exchange experience, identify possible improvements and learn from each other."

Jun 1, 2012

By S Thomson, G Rigby, J Norgard, D Wilkinson

Bulk explosives provide the energy to move a rock mass and reduce it to an optimal size (fragmentation). The intensity of energy needed depends on several factors including a customer’s geology and end objectives. An energy mapping tool has been developed to help customers to determine their bulk explosive needs based on these objectives.At one end of the energy map dealing with high-energy products, a new range of bulk explosives products for surface mining have been developed. With these products, it is possible to provide blast designs with up to nearly triple the relative bulk strength (RBS) of ANFO, and address primary focus areas for mining operations, including the reduction of drill and blast costs, improvements in production rates, better face advance through improved broken stock management, better drill productivity, improved milling efficiency and lower energy costs in surface mines.In this paper, field trial results from the first level of new high-energy products are presented. These products have an RBS 2.25 times that of ANFO. Industry variations of a smaller diameter (89 mm) pumped product for civil quarrying applications, and for large diameter (311 mm) hard-rock metalliferous mines are presented. For both cases, the run-of-mine fragmentation levels obtained with the new bulk explosives are contrasted with the fragmentation profile generated with the currently accepted product range applied in similar geological conditions. The new products show increased fragmentation across the measured size distribution, with reduction in P50 values of 20 and 37 per cent over the currently used product for the 311 mm and 89 mm diameter blastholes respectively.CITATION:Wilkinson, D, Rigby, G, Norgard, J and Thomson, S, 2015. Higher energy bulk explosives – matching products to rock types using an energy map concept, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 579–584 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By L M. Zhang, X Y. Li

Surface displacements are routinely monitored at multiple points during slope excavation. The monitoring data reveals the safety status of the slope under current loading conditions. They can be used to enhance the prediction of the future performance of the slope by reducing the uncertainties of the prediction model and its model parameters. In a multistage excavation, the observed displacements in the current stage can be used to update the prediction of the displacements in subsequent stages. Besides, due to the spatial correlation of the slope parameters, the prediction of the displacement at one location can also be updated using the monitored displacements at adjacent locations. This study aims to develop a multistep updating method to enhance the prediction of the future performance of the slope using time-series monitoring data at multiple points. This method integrates the theoretical computational model with observational evidence. It considers the inherent uncertainty of the slope, model uncertainty and measurement uncertainty. With more monitoring information being incorporated, the prediction becomes closer to the actual performance of the slope. A case study of a multistage excavation of an extremely high rock slope in south-west China is presented for illustration.CITATION:Li, X Y and Zhang, L M, 2014. Better prediction of performance of a slope using time-series monitoring data at multiple points in a multistep excavation, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 183–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

For over 50 years R W Miller & Co Pty Ltd operated old coal properties abandoned by former owners as uneconomic, some of which dated back to the last century. The companyÆs ability to survive with what were relatively poor quality coal resources required a small efficient management organisation. In 1970 R W Miller was involved in negotiations with other coal companies through coal sales contracts to develop private coal areas under the provisions of the old Coal Mining Act (1906) and these efforts led to the development of Lemington colliery. At the same time development of the Ironbark colliery holding near Newcastle commenced. In 1971, R W Miller approached the New South Wales Government for a resource replacement area to prospect for coal in the Upper Hunter Valley. Authorisation No 33 was finally granted on 30 September 1975, but the company found the area was inaccessible as most of the surface was owned by the Australian Army. Later R W Miller was granted Authorisation 66 of 2167.5 hectares at Mount Thorley near Singleton on 1 November 1976. The development of this coal mining project coincided with the second OPEC oil crisis in 1978 and a short-term boom for coal resources and the unrealistic expectations generated by the boom. This paper gives a broad outline of the development of the Mount Thorley project between 1976 to 1986 including the feasibility study and the many governmental and industrial delays that resulted in a three-year time overrun in the project development period.

Jan 1, 1998

By M I. Pownceby, N A. S Webster, A J. Studer, I C. Madsen, J A. Kimpton, M J. Fisher-White, L Lu

In situ synchrotron X-ray and in situ neutron diffraction-based experimentation have been implemented to characterise the formation of the complex calcium ferrite iron ore sinter bonding phases silico-ferrite of calcium and aluminium (SFCA) and SFCA-I. Experiments were carried out using fine-grained (<20 ¦m) sinter mixtures containing ~77 wt per cent Fe2O3, 14 wt per cent CaO, 3.5 wt per cent SiO2 and 5 wt per cent Al2O3, with diffraction data collected during heating until 1300 - 1350¦C, which was enough to ensure complete melting of the SFCA phases. In the case of the in situ synchrotron experimentation, results showed that altering the nature of the starting sinter mixture (ie substitution of goethite for hematite; substitution of an amorphous Al2O3-based mineral for gibbsite) did not have a significant effect on the thermal stability range of the SFCA phases. It did, however, have a profound effect on the formation and rate of consumption of the calcium-rich ferrite phases C2F and CF, and on the formation mechanisms of SFCA and SFCA-I. The in situ neutron diffraction experimentation is the first described in the context of iron ore sintering, and the observation of both SFCA-I and SFCA formation in the in situ diffraction data represents the first step in achieving the goal of charactering iron ore sinter phase formation in large volumes of industrial sinter starting materials with a wide range of particle sizes (up to 6.3 mm).CITATION:Webster, N A S, Pownceby, M I, Madsen, I C, Studer, A J, Lu, L, Manuel, J R, Kimpton, J A and Fisher-White, M J, 2013. In situ x-ray and neutron diffraction studies of silico-ferrite of calcium and aluminium iron ore sinter phase formation, in Proceedings Iron Ore 2013 , pp 487-494 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By A Winchester, D Grant

The massive 1100 Orebody in Mount IsaÆs X41 Copper Mine has been extracted over the last 40 years form north to south utilising sublevel open stoping methods.De velopment has continually stepped ahead of production to provide access to new primary stoping blocks. The remaining secondary pillars contain stopes with one, two or three fill mass exposures and were constrained by access requirements and stope extraction turnaround time.The remaining southern mining areas consist of large 40 m wide by 300 to 400 m long east-west transverse pillars that have been left to provide access for ventilation and service requirements. Three large transverse cross-cuts or transverse pillars û 4180 x/c, 4010 x/c and the Panel pillar now remain. The 4180 x/c was the last major transverse pillar to be successfully broken.This transverse pillar is being extracted in a retreating sequence, creating 3SLOS stopes due to the surrounding backfilled stopes.In recent years the extraction of the first, and most critical, stopes in the transverse pillars have resulted in large changes to the induced stress field. This paper describes the extraction of the 1.1 million tonne stope P418 in the 4180 x/c pillar.T echnical challenges that were faced and how they were overcome to allow for the successful extraction of the stope are described.Critical to the success of the P418 stope extraction were the rehabilitation methodology used; extraction strategy modifications to address deteriorating ground; mass firings with multiple directional changes; managing the exposure of backfill of variable strengths; and geotechnical monitoring prior to, during and after extraction.

Jan 1, 2005

Alcoa of Australia's Del Park mining op eration is centred 9 km. east of the Pinjarra alumina refinery, and is centrally locatedwith- in the 10, 000 sq. km. lease which the Company holds for bauxite in the Darling Ranges. An- other mining operation is situated near the township of Jarrahdale, and supplies bauxite to the Kwinana refinery. Definition of the bauxite ore, development works and mining to the ore haulage stage, are identical for both mining operations. Exper- ience, and production cost figures, obtained from the Jarrahdale mine, where 100 tonne trucks are used to haul ore to a fixed crushing plant, led to the development of the Del Park mining concept with increased mobility of op- erations. The crushing-conveying-stockpiling arrangement at Del Park consists of a 1200 t. p. h. mobile crusher feeding bauxite to an overland conveyor system which transports the ore approximately 6. 66 km. to the stockpile area in the refinery. In the refinery raw mat- erials area the bauxite is distributed into 200, 000 tonne stockpiles by means of a travel- ling boom stacker.

Jan 1, 1973

By P J. Terbrugge

The concept of vertical pit mining has been developed as an alternative mining method for the exploitation from surface of small, vertical or near-vertical, massive orebodies down to depths of some 200 m, where ore extraction from conventional open pit excavations is rendered uneconomic due to high associated waste:ore mining ratio. Systematic lateral support maintains vertical pit sides, thereby minimising waste mining volumes. Stability analysis techniques have been developed for design of this lateral support, with the support quantum, primarily comprising long cable anchors, dependent upon country rock strength characteristics and pit configuration. Where the cost of support is less than the cost of the comparable conventional pit waste excavation, vertical pit mining becomes an economically viable alternative, additionally providing the benefit of reduced environmental impact and rehabilitation requirements for the mining area. The technique has been successfully applied for the mining of a chrome deposit in Zimbabwe to an 80 m depth, believed to be unique in the world, and a full feasibilty study for a 3000 m2 diamond pipe has been carried out for mining to 200 m depth.

Jan 1, 2000

This research is about human development and socio-economic progress of the main mining areas of Chile in the period 1990 - 2007, and especially about the positive effects that mining activity has on poverty reduction and indicators related to the Millennium Development Goals of the United Nations. The analysis is doubly interesting, if one considers that the economic and social developments in Chile, recognised and prominent among the Latin American economies and developing nations, are more evident in mining areas as Tarapacß and Antofagasta (northern Chile), which concentrated than more 70 per cent of investments and mining assets in the country. Additionally, the study concludes with methodological reflections for the evaluation of socio-economic impact in the mining industry in developing countries.

Jan 1, 2009

The theme i wish to develop in this talk is how we might make use of the scientific and technological knowledge we now have ofextraction metallurgy to meet the present-day needs of the production industry.Before doing so, I would like to say a few words in tribute to Dr. G.K. Williams since he was a past master at precisely what I wish to talk about. I knew G.K., as everybody called him, during the time he spent at Avonmouth in the late 40's and in the 50's. Later, when he was ostensibly retired, I had the pleasure several times of lunching with him when I was visiting Melbourne.When G.K. was at Avonmouth, the Imperial Smelting Process was in that capricious adolescent stage in between the pilot plant and the full-scale commercial unit. G.K. was a great collector of process plant data which hung in cascades from the walls of his office and-from his hand-operated desk calculator. What G.K. understood very well were the basic metallurgical and engineering principles of what was going on in the sinter machine, the shaft furnace and all their ancillaries.

Jan 1, 1985

By Grano S. R, Ralston J

It is the perennial problem most metallurgists face when examining data collected from laboratory float tests and plant surveys - there are more numbers than we know what to do with! The objective of this paper is to analyse and interpret a set

Jan 1, 1994

By C MacRae, N Wilson

CSIRO Minerals has recently developed an electron microprobe (EMP) based imaging (or mapping) method for characterising ilmenite concentrates. The method requires an electron microprobe analyser to collect elemental X-ray maps which are then processed via an in-house developed software module (CHIMAGE). The type of information readily available from EMP mapping includes; primary phase identification, modal analysis of phases, chemical analysis of individual phases, textural information (eg the alteration stages in the formation of leucoxene or pseudorutile from primary ilmenite and the development of macro-porosity), and the identification of coatings or pore-fill material. All of these parameters will impact on the choice of future downstream processing options considered for any particular ilmenite concentrate. The method has been demonstrated to be a sensitive analytical tool for assessing the distribution of aluminosilicate minor impurities in ilmenite feedstocks from the West Coast of Australia and also for characterising the complex chrome-spinel gangue phases common in East Coast ilmenite concentrates from the Murray Basin.

Jan 1, 2001

This paper explores options worthy of consideration in the management of S02 produced from the gold roasting operations at Kalgoorlie. Some of the options have relevance to other sources of SO2 in the region, eminating from nickel smelting operations. The paper considers the following options: 1. Capture of SO2 within the roaster where sulphur-containing reaction products are mixed with the calcine. 2. Processes in which the sulphur-containing products are bled separately from the stack for further treatment or for dumping as a waste. These include: Seawater-based scrubbing of SO2; Sulphuric acid manufacture as a feedstock for fertiliser production or for leaching of bauxite; its use as Caro's acid: and the production of value-added sulphur-containing reagents eg liquid S02 and sulphonic acid.

Jan 1, 1992

By N Winkelmann

Underground coal heating is a significant hazard in some coal mines. The broad principles of how underground coal heatings occur is reasonably known, however the technique for locating the heatings in often inaccessible goaf has been proved to be difficult. Since 2002, CSIRO, with the support of the Australian Coal Association Research Program (ACARP) has been undertaking investigations to apply and develop innovative surface-based radon technique for locating the underground heatings in Australia. This paper presents the progress of the investigation.

Jan 1, 2005