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Contracts are widely used in mining to provide self motivation in an environ-ment of isolated work places. Which incentives to use and how to implement them has long been the subject of numerous discussions. The mines operated by Australian Mining and Smelting at Broken Hill have evolved several guidelines to follow when developing contracts.Identify the main purpose of the work and use this as the basis of measurement for the contract. Therefore stoping achievement would be measured by tonnes extracted, development by metres driven. Paying for other work activities such as standing timber in timber stoping must detract from the percentage of the total contract paid per tonne produced. Concentrating on the main activity and applying the majority of contract pay to that task reinforces at is beneficial to both the miners and the whole operation.

Jan 1, 1985

By D Wallace, H Guo, B Shen

Appropriate management of the ground subsidence induced by coal mining activities is essential. To assess the effectiveness of grout injection for mining subsidence control, time-lapse ground penetrating radar (GPR) imaging data were collected before and after grouting. The pregouting subsurface responses were interpreted to have changed after grout injection. The changes were caused by injecting the grout materials (flyash and water) into the delaminated strata and permeable fracture zones. The largest distance of the observed GPR event changes at the right end of the main profile is 132 m away from the injection borehole. Although the GPR images could not easily tell if the image changes were caused by the injected ashes or the water, it does suggest that the injection materials had been pushed at least 130 m away from the injection borehole. This is consistent with the borehole scan monitoring, which confirmed that the grout has travelled more than 90 m from the injection borehole.

Jan 1, 2006

By Liu H, Chen S

Natroalunite is one of colouring minerals in kaolin. In this investigation, natroalunite, on which Ca(II) was adsorbed, was flocculated by HPAM and kaolin was depressed in suspension. The adsorption of Ca(II) on the natroalunite surface was studied by zeta-potential measurement and Auger Electron Spectroscopy analysis. Ca(II) was adsorbed more on the natroalunite surface than on the kaolin surface. The mechanism of Ca(II) adsorption was considered to be chemical adsorption on natroalunite and to be physical adsorption on kaolin. It has been found that Na6P6O18 and Na2Si04 can strongly affect Ca(II) adsorption on the surface of kaolin, but weakly on the surface of natroalunite. The effects of degree of hydrolysis and the molecular weight of HPAM, the effect of pH and the effect of Ca(II) have been studied. The kaolin ore, containing SO3 1.05 per cent has been processed with this method. The products only containing S03 0.36 per cent and the weight ratio of concentrate 52.27 per cent were Obtained.

Jan 1, 1993

Various aspects of the history of mining at The Zinc Corporation, Limited (ZC) and New Broken Hill Consolidated Limited (NHHC) are examined. There are some discussions about the various methods used to mine the pillars left after the primary mining operations, with an enphasis being placed on the more modern pillar mining methods. Some new pillar mining proposals are presented. INTRODUCTION In the past, pillar reserves at ZC/NBHC have been scheduled for mining by labour intensive and high unit cost mining methods. These methods include both undercut and fill and overhand square set timber stoping. Recent technological advances in large diameter longhole drilling and high charge density explosives have culminated in the mechanised Vertical Crater Retreat (VCR) mining method and this method has been successfully used for the extraction of two pillars at NBHC and more stopes are planned. However the use of VCR methods for mining pillars at ZC/NBHC is restricted to approximately 50 per cent of the total pillar reserves and it appears that high cost methods will be needed to mine the remaining Pillars.

Jan 1, 1983

Computational models are very useful for studying many of the physical mechanisms which can cause sample bias. Within such models we can predict the trajectories of all individual particles and thereby make observations which are not possible for physical systems. Physical mechanisms highlighted include congestion at the cutter aperture, particles bouncing over the cutter aperture, air drag on fine particles, waves of material being bulldozed off the belt by the upstream side of the body of square cutters, and particles being thrown by the leading edges of cross-belt cutter blades. Having identified relevant physical mechanisms for an existing cutter, we can estimate the extent to which they are likely to result in unequal representation of portions of a stream of material and thereby estimate the maximum likely sample bias.

Mar 1, 2010

By J Li, J Regan, D Payne

The Caval Ridge Mine is an open cut coalmine and located within the Bowen Basin region in Central Queensland, and commenced mining and processing operations in 2014. A number of geotechnical challenges for managing dragline bench and lowwall stabilities have been encountered in both southern and northern pits over the years. Southern Pits contain steep seam dips of up to 15° (27 per cent) whilst the northern pits also have shears below pit floors. Geotechnical guidelines to manage the risk of dragline bench failure and lowwall instability have been developed and improved since these geotechnical challenges were identified. The dragline guidelines include dragline tub offset distances from the 60° Line (SDL) or buttressing thickness for different seam dips greater than or equal to 8°. The low wall stabilisation guideline established floor disruption widths and depths depending on seam dips and presence of floor shears to known depths of up to 3 m. As mining operations advance, lowwalls have remained stable until floor disruptions were fired, then returned to stable soon after the shot. The maximum distance of lowwall cracking with blasting has been as far back as the second spoil peak (the prestrip truck dumps construction limit). These failures need to be eliminated to allow the operational flexibility and haulage benefit of constructing the prestrip truck dumps behind the first spoil peak, while maintaining no risk to personnel or equipment. The floor shear depth was verified by collaborating with the exploration teams and taking advantage of the already planned 8-inch coal quality core holes, drilling them an extra 5–10 m past the coal seam floor and locating the shear presence. With this continuous improvement effort, no lowwall failures have occurred during floor disruption firing from the second strip after the new floor disruption depth guidance have been applied. This paper documents the processes for developing these geotechnical guidelines, operational implementation, and outcomes. Operational applications over the years confirmed that these guidelines have effectively managed the dragline bench and lowwall failure risks related with the steep seam dips and floor shears in this open cut coalmine.

Nov 29, 2022

By K Kuganathan

This paper describes a new methodology that can be applied to compare several bench extraction strategies requiring backfill. The method is applicable at the planning or operational stages and can be used to maintain dilution within design parameters and improve the overall economics of bench stoping operations. The parameters influencing bench performance have been empirically rated based on economical, geomechanical, operational and backfill properties. Four different extraction strategies have been considered and rated from most preferred to less preferred using an integrated approach to bench extraction.

Jan 1, 1998

The present-day arrangement of old ( ? ) Palaeozoic and Mesozoic metamorphic rocks in eastern New Guinea lends some support to the concept of tens:konal dilation in Upper Cretaceous to Lower Tertiary time, It appears that the metamorphic core of the Morobe Arc (Glaessner, 1950) could have been rifted from the eastern flank of Cape York Peninsula, and then been carried north-eastward by some unspecified sub-crustal. tangential force. In the early stages of the rift it is thought.that submarine basalts may have extruded up the .'tension .scar and spread across the floor of the opening rift. Thick clastic muddy sediments derived almost exclusively from the rifted block were then spread across the floor of the opening rift. Later ~ertiary lateral movements from east to west along the Markham-Ramu Fault appear to have bent the northern end of the Morobe Arc towards the.east,,causing the intense folding in the sediments of the Aure Trough.

Jan 1, 1962

The prospect of utilization of phosphate ores which contain high P205 values associated with Al and Fe has produced a great deal of interest over many years. Processing options have generally been based on the utilization of by-products which were required to offset the processing costs.This paper presents a range of processing options which have been investigated at laboratory or technical scale on phosphate ores which predominantly consist of crandallite, CaA13(PO4)2(OH)5.3H20 and millisite, Ca(NaK)Al6(PO4)4(OH)9.3H20. Christmas Island (Indian Ocean) and Mt. Weld (Western Australia) phosphate ores are good examples of such feedstocks. It is expected that these processes may also be applicable to such phosphate ores from other locations.

Jan 1, 1990

By M M. Collisson

The Synthetic Rutile (SR) plant operations, North Capel, produce electrostatic precipitator (ESP) fume and kiln scrubber residue. Typically ESP contains about 18 per cent Ti, 13 per cent Fe, 0.5 per cent Mn, eight per cent Si, six per cent Al, 16 per cent C, 0.9 per cent Zn, 0.6 per cent Pb, 300 ppm As, 300 ppm Cr and 5 ppm Cd. These wastes are held in a storage dam together with neutralised acid effluent (AE) liquor. A project was initiated to treat the fume and produce a benign residue that could be delivered to landfill, reducing dam space storage. Plant AE, containing free acid (9 - 14 g/L), Fe (6 - 7 g/L) and Mn (1 g/L), was used to leach ESP. The degree of extraction achieved for various elements include about 20 per cent Zn, almost 50 per cent As, five per cent Al, 0.4 per cent Pb and 15 per cent Cd. Extraction was most effective at pH The residue from AE leaching still contained Pb. TCLP tests of the leach residue produced Pb extraction significantly higher than the 0.1 ppm stipulated by Class 2 landfill guidelines. Other elements (eg As, Cd, Cr) successfully met the limits. Further leaching of the residue with EDTA extracted up to 65 per cent of Pb content. TCLP tests on treated residue showed Pb leaching potential of Lead was removed from the leach circuit as the sulphate by acidification of EDTA leach liquor, allowing EDTA to be recycled. The study showed that one waste stream can be used to treat another and help reduce plant waste.

Jan 1, 2001

By Milawarma E, Cusack C

The Sapan Dalam coal deposit of Indonesia consists of ten steeply dipping seams with thicknesses varying between 0.1 and 3.5 m and split by shale, clay, silt and sandstone. The area contains four faults dipping about 75¦ with four to 85 m vertical displacements. The complex nature of the deposit coupled with limited 27 exploration drillholes at an average spacing of 200 m made it difficult to create a realistic geological model. A three-dimensional gridded seam model gave a fair representation of the deposit. Attempt to create an optimum pit using the WHITTLE 3D pit optimiser proved unsuccessful since the pit optimiser is restricted to standard regular or fixed blocks. The gridded seam model was converted to a fixed block model prior to the optimum pit design. Smoothing and pit base controlling were also introduced to obtain a smoother pit. A mining scenario produced 3.6 million tonnes of coal, 28.4 million bcm of waste and US$18.1 million revenue.

Jan 1, 1995

By H Thanasekaran, M J. Mankosa, J N. Kohmuench, G H. Luttrell

"Fluidised-bed flotation has been demonstrated over the last 16 years as an effective method for improving the flotation recovery of coarse particles. This technology has been successfully deployed into the industrial mineral sector with multiple installations within phosphate beneficiation plants and potash mills. Due to the minimal mineral surface expression required when utilising this technology, more recent studies have centred on the applicability of using this HydroFloat™ technology for the recovery of coarse sulfides and base metals. Multiple approaches have been investigated to determine the best means for implementing this novel coarse particle flotation system into both existing and new plant circuitry. These include the treatment of tailings to recover values that have been lost using conventional technologies and also the direct treatment of a coarse feed, either within the grinding circuit or by use of a separate split-feed flotation approach. Recent applications of the technology will be presented along with data generated from several test campaigns and ongoing research investigations. The benefits of properly applying this technology, such as reduced power consumption and increased mill capacity will be discussed.Citation:Kohmuench, J N, Thanasekaran, H, Mankosa, M J and Luttrell, G H, 2016. The Impact of Fluidised-bed Flotation for Treating Coarse Sulfides, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 105–112 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By D J Maconochie

The use of rock bolts as permanent support has been prohibited by client specifications in several recent large tunnel projects in Australia. The justification for this appears to lie in concerns with proper and verifiable installation procedures rather than concerns with the intrinsic durability of the corrosion protection systems. However, in civil tunnels, preventing the use of permanent rock bolts for long-term support results in the use of cast in place concrete lining which in some instances would otherwise be unnecessary.

Mar 8, 2011

Much of the data required for the evaluation of mine design is obtained from bore cores. It is essential to collect data that is useful and not to overlook features which might have adverse effects upon the mining practices and which might not be readily discernible to the untrained eye when examining bore cores. Interpretation of the data has progressed from the use of single-value properties, such as ultimate compressive strength or Young's modulus, to the utilisation of most measurable quantities. The simulation techniques used employ physical and mathematical models for prediction of mining conditions or strata behaviour. The application and capabilities of these methods to mine design are discussed.

Jan 1, 1977

By J Seppelt, B Akerstrom, J Bubnich, D Seaman, T Waters

The Cadia Hill concentrator at Newcrest’s Cadia Operations has undergone several modifications and upgrades to treat an increased throughput rate of harder ore from the Cadia East block cave mine.Subsequent to the commissioning of the expanded circuit, the flotation cleaner block has undergone a systematic optimisation programme tackling all facets of circuit operation. This included debottlenecking circuit constraints and installation of Jameson cell technology to enhance copper and gold recovery while rejecting fluorine and gangue from the concentrate.This paper outlines the improvements over the course of the project and results obtained from the implemented actions.CITATION:Akerstrom, B, Seppelt, J, Waters, T, Bubnich, J and Seaman, D, 2018. Cleaner circuit optimisation at Cadia Operations, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 457–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Davies K. E

Several nuclear techniques have been assessed for application to online conveyor belt analysis of oil yield from Rundle oil shale. The most favourable technique is neutron inelastic scattering which determines the total carbon content of bulk shale samples. Correlations of chemical laboratory assays for 540 Rundle oil shale samples show that oil yield can be predicted from total carbon to within 11 litre/tonne.Laboratory experimental work on 17 bulk samples of Rundle oil shale indicated that carbon and oil yield can be determined to within 0.6 wt per cent and 9 litre/tonne, respectively, using the neutron inelastic scatter technique. A practical neutron inelastic scatter gauge for application on a 23 mm thick reinforced conveyor belt could consist of a 5 curie 241 Am-Be neutron source and a 150 mm diameter x 100 mm thick Nal(TI) detector. With this gauge, the analysis time to achieve a counting statistical error of 6 litre/tonne should be about five minutes.

Jan 1, 1985

By M Wortley, J McKay, D La Rosa, O Guyo

It has been a generally held concept that crushing operations were, by their nature, too simple to benefit from the implementation of advanced process control. The commissioning of an OCS¬ expert control system and image-based oversize detection system, VisioRock, at the Pilbara Iron Tom Price facility are dispelling these notions. A constraint-based OCS¬ expert control system has been designed and commissioned on the high-grade crushing and screening plant along with a vision-based oversize detection system functioning on six product conveyor belts. To date, the expert control has demonstrated the ability to increase production by maximising dynamic constraint utilisation. Dynamic constraint utilisation is a concept developed by Rio Tinto Technical Services for effectively evaluating constraint-based control logic performance. The VisioRock system has been installed and configured and has been operating for a period of several months. Currently, Tom Price and Metso personnel are working to define correct oversize detection thresholds. Details of the plant implementation are discussed.

Jan 1, 2005

By Weatherstone N

Ironstone outcrops on the Savage River were discovered by State Government Surveyor C. P. Sprent in 1877. The limonitic outcrops were initially regarded as the surface expressions of pos- sible tin-bearing lodes, the tin deposits at Mt. Bischoff to the east having been found in 1871. By the turn of the century, shafts, adits and trenches had been developed on the deposits in the unsuccessful quest for gold, silver and base metals. The deposits were first reported as a possible source of iron ore by Tasmania Department of Mines (TDM) geologists in 1919. Modern exploration began in 1956 with the area registering the best magnetic response during an aeromagnetic survey of North- western Tasmania by the Bureau of Mineral Resources (BMR). The area had previously been reserved by TDM in anticipation of the lifting of the iron ore embargo. Reconnaissance Geologi- cal mapping (TDM) and grid-based magnetometer surveys (BMR) indicated that resources of iron-bearing material could approach hundreds of millions of tons. This provided the incentive for two diamond drill holes funded by TDM which demonstrated iron mineralisation in substantial tonnages, suitable grades and, fol

Jan 1, 1988

By K Knorr, S Birch

The mineralogy of new certified-reference-materials (CRM) for X-ray fluorescence from Western Australia (ASCRM 030 to 035) was analysed by X-ray diffraction using the BRUKER energy dispersive one-dimensional detector LYNXEYE-XE. The samples were studied using standard-less quantitative phase analysis, based on the Rietveld method. This method delivers the relative amount of crystalline phases. All materials were found to be high-grade iron ore predominantly consisting of hematite and goethite and very low amounts of magnetite. In addition, the gangue mineralogy was characterised. It consists of low-per cent amounts of carbonate (siderite/calcite), quartz, kaolinite, chlorite and gibbsite.Furthermore, all samples were analysed with the external standard method. This is an elegant way to probe for amorphous content without adding an internal standard. All six samples were found to contain up to 16 per cent amorphous or nano-crystalline material.CITATION:Knorr, K and Birch, S, 2013. Mineralogy of new Australian x-ray fluorescence standards, in Proceedings Iron Ore 2013 , pp 269-274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

Mount Isa Mines has been mining base metals since 1924. Annual production is currently 185 000 tonnes of crude lead, 207 000 tonnes of anode copper and 361 000 tonnes of zinc concentrate. This is achieved by underground mining of 11.7 million tonnes of ore followed by traditional flotation concentration and smelting operations.

Jan 1, 1976