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By I Gray

This paper examines the practical limitations that affect the measurement of stress in rock. As most rock stress measurement is conducted through the invasive process of drilling a hole in a rock mass, the nature of the rock and its response to being drilled form the basis of the stress measurement process. The prime techniques to measure stress down a borehole are to conduct hydraulic fracturing and its variant hydrojacking, overcoring, and the examination of the borehole wall for breakout or tensile fracture. It is also possible in some circumstances to use the sonic velocity within the rock mass as an indicator of the stress situation. Other structural indicators of stress such as joints, faulting and intrusions are useful but may not reflect the current stress situation within the rock mass. The variability of stress within the rock mass also needs to be considered as it is quite unusual to have a monotonic stress situation throughout any rock mass. The outdated concept of measuring the far field stress in a few measurement for use in a numerical model is quite dangerous. It is essential to make multiple measurements and to generate an understanding of its distribution in some form of model before stress can sensibly be incorporated into underground design. CITATION:Gray, I, 2018. The practicalities of effective stress measurement in rock, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 360–374 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By S Morgan, D J. Bradshaw, S Schwarz

The characterisation of the flotation kinetic response in future mining deposits is important because the flotation response is affected by changes in ore mineralogy. Current methods for characterising the flotation response of different ore types, such as the JK floatability index test (JKFIT) methodology, require at least 10 kg of feed material. In geometallurgical applications, this material is taken from core samples. Core samples are generally obtained using specialised drills and are limited in nature. Thus, it would be beneficial to develop a laboratory technique that required less sample material but still characterised the flotation response of different ore types. The JK mineral separation index (JKMSi) is a small-scale flotation test that requires significantly less feed material (10 g of sample/data point). This study aims to investigate the JKMSi system kinetics and to validate this technique using the JKFIT proven methodology. The JKMSi flotation kinetics were manipulated by varying selected system parameters. The relationship between these parameters and mineral recovery was used to obtain floatability characteristics of the ore. For an ore sample containing chalcopyrite and pyrite, it was found that the chalcopyrite floatability parameters determined from both the JKMSi and JKFIT tests were of the same order of magnitude and the mass fractions of the fast, slow and non-floating components were similar. For pyrite, the floatability parameters were not of the same order of magnitude, but modifications to the test procedure have been identified, which may correct this.CITATION:Morgan, S, Bradshaw, D J and Schwarz, S, 2012. Julius Kruttschnitt Mineral Separation Index - Small-scale test to characterise the flotation response of an ore type, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 159-162 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The main orebody of the Bodangora mine is a metalliferous quartz reef within a major fault plane in the strongly folded and faulted volcanic rocks of the Ordovician-Silurian Oakdale Formation. The similarity of the type of mineralization to that of other pyrometasomatic deposits in this area suggests that the mineralizing fluids originated in the nearby Wuuluman Granite.The associated Mitchell's Creek West or Dick's reef is discussed briefly.

Jan 1, 1970

By J Joughin, D Kyan, L Rollin

In line with the 2015 Paris Agreement and corresponding climate disclosure requirements, many mining companies have publicly disclosed that they are developing and/or implementing ambitious decarbonisation strategies. Sometimes these strategies can be linked to the development of community programs and/or the creation of a positive legacy post-closure. Renewable power is key to most decarbonisation strategies – some mines will get this from external sources and others will establish on-site power generation and storage facilities. A range of options are available to develop renewable power generation (eg solar panel, wind farm, hydropower) and energy storage (eg battery, hydrogen, pumped hydroelectricity). Land access, impact assessments, planning and environmental approvals are required to establish new facilities. Host communities are more likely to be in favour of, or at least will accommodate, new power supply developments if these are planned with a benefit to the communities. Transitioning to renewables raises new challenges. Among these are high upfront costs and access to capital, energy demand variability, supply intermittency and variability, storage limitations, grid stability and reliability, transmission and distribution infrastructure constraints. Compounding these challenges are issues such as infrastructure resilience to extreme weather events (eg heat, wind), land use and access, lengthy permitting processes, community perceptions, skilled labour requirements, and meeting mine closure objectives. Renewable energy sources provide a more decentralised source of energy that reduces reliance on imported fuels, thereby increasing energy security and lowering production costs. On the contrary, implementing renewable energy could lead to potential negative impacts such as visual perception from the community, competitive land usage, electricity price raises due to upgrading infrastructure and the use of electricity storage capacities. As part of the definition of an environmental and social management plan, participative stakeholder engagement is required to identify benefits to the communities. For example, among the recognised benefits of developing solar panels (increase job opportunities, reduce soil erosion), various technologies have been experimented globally for the last ten years and are emerging due to their proven community benefits. Key findings to enhance those benefits can range from the development of innovative practices such as ‘agri-/aqua-voltaic’, ‘solar grazing’ to optimise land usage and stimulate the local economy (Table 1), to the implementation of technologies providing services to communities such as mobile water desalination plants or ‘smart grid’ systems to minimise energy clipping during peak-load of oversized renewable energy facilities (Table 2). While developing those synergies, careful management is required to avoid creating superfluous energy service needs from community programs. Energy sufficiency should remain a key principle according to the sufficiency, efficiency and renewable framework of the Intergovernmental Panel on Climate Change. Darby and Fawcett (2018) define energy sufficiency has ‘a state in which people’s basic needs for energy services are met equitably and ecological limits are respected’. Sufficiency tackles the causes of the environmental impacts of human activities by avoiding the demand for energy and materials over the life cycle of buildings and goods. Efficiency tackles the symptoms of the environmental impacts of human activities by improving energy and material intensities. The third pillar, renewables, tackles the consequences of the environmental impacts of human activities by reducing the carbon intensity of energy supply (Cabeza et al, 2022). Life of Mine Conference 2023 | Brisbane, Australia | 2–4 August 2023 34 This paper provides project developers, decision-makers and regulatory authorities with ideas on synergies between renewable energy options and community development programs. These can be considered to enhance stakeholders’ support for implementation of decarbonisation strategies.

Aug 2, 2023

Single particle breakage tests have been used by a number of researchers to investigate some salient features of the complex comminution process. The characteristics of the common single particle breakage tests such as single impact, double impact and slow compression tests are examined and the results from these tests are compared. A comparison of the results from single particle breakage tests with grindability and ball mill tests is given. Application of the results from single particle breakage tests to modelling industrial comminution processes is described. The necessity for further research into single particle breakage tests to develop a simple but comprehensive technique for estimating the breakage characteristics of ores is discussed.

Jan 1, 1986

By Bhattacharyya A. K

A major constraint on sustaining high rates of production in the collieries of the Southern Coalfield of New South Wales is the inability to develop panels fast enough to match the rates of extraction. This inability is particularly crippling in the case of retreat longwall mining and is due to nearly half the time in roadway drivage being spent on strata control operations such as roof support.Increased rates of roadway drivage and significantly improved roadway stability can be achieved by the application of yield pillars between parallel roadways. These pillars are designed to yield immediately upon formation and transfer the damaging roof loads away from the immediate vicinity of the roadways. Since the width of the yield pillar is the key to their successful application, it was determined through the Yield Pillar Experiment conducted by Kembla Coal and Coke Pty Ltd at West Cliff Colliery.Three experimental headings, each nominally 5.5 m wide and 2.8 m high, were driven to form two tapering pillars. The width of these pillars progressively decreased from 24 m to 3 m over a length of 154 m. The convergence between the roof and floor of the headings measured at various cross-sections corresponding to predetermined widths of the pillars are analysed in this paper to evaluate the stability of the tapering pillars at the different widths.The width of the yield pillar in a three heading development layout at West Cliff Colliery was determined to be 7.5 m.

Jan 1, 1995

This evening I intend to explain the position of the gold mining industry in the light of post war trends and events.I propose initially to comment on gold production throughout the World and then proceed to the state of the industry in Australia, with an account of the efforts made within the industry to maintain levels of production. This will be followed hy a statement on assistance granted to the industry by Federal and State Governments.Annual World gold production is estimated at 51,000,060 fine ounces, made up as followsSouth Africa - 27,300,000 fine ouncesCanada 4,200,000 " "U.S.A. 1,500,000 " "Australia - 1,000,000 " " Others 5,000,000 " "----- 39,000,000 " "Estimated Russianproduction - 12,000,000 " "Total 51,000,000 " "The opening up of new highly payable mines during the post war years has contributed to the preponderence of production in South Africa.In 1962 some 24 new mines produced 73 per cent of South Africa's gold, and contributed almost 90 per cent to the industrial profits.At the same time, 20 old mines were struggling to main...

Jan 1, 1964

The problems of using comparatively simple x-ray diffraction equipment for quantitative analysis are examined. Internal standard and direct calibration procedures based upon the measurement of integrated diffraction energy (diffractometer peak area) have been developed for the determination of quartz in Broken Hill dusts. By these methods an accuracy of ± 10 per cent of the true value can be obtained and this can be improved to ±2 1/2 per cent by statistical methods if necessary.Rapid analysis for the components quartz, muscovite, rhodonite, galena, fluorite, sphalerite, calcite, and garnet has been developed by adaptation of direct calibration procedures and use of maximum diffraction energies (diffractometer peak height). Until more is know!) about the pathological effects of multi-component dusts of the Broken Hill type it seems undesirable to fix theIr allowable concentrations in terms of the quartz content.

Jan 1, 1968

By D W. Stevens

Mechanical sampling provides a definitive value for the product sampled but the results are not instantaneous, meaning that decisions on process control can only be made hours after the sample is taken. Chemicals are added, tailings are sent to waste, stockyards are laid and the data for the decision-making is historical. Online analysers provide instantaneous information, allowing operators to make immediate and cost-saving decisions on the process. However, pending the specific online analysis application, there is a need for reference sampling for dynamic calibration/bias updating of the analysers so that they can deliver the desired precision and accuracy. What would be the economic justification for combining mechanical sampling with online analysis to reduce laboratory costs and provide immediate process control with certainty of accuracy? Approved sampling according to the Theory of Sampling, with immediate process control information.CITATION:Stevens, D W, 2014. Justification for integrating mechanical sampling with online analysis, in Proceedings Sampling 2014 , pp 135–138 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By H Susanto, N Belluz, D Flint, A Edw

The Deep Ore Zone (DOZ) is a block cave mining operation exploiting a diluted reserve of 131 million tonnes grading 1.06 per cent copper and 0.81 g/t gold in the lower portion of the Ertsberg East Skarn System (EESS). The EESS is a calcium-magnesium silicate skarn containing in excess of 250 million tonnes of copper-gold ore, located in the Ertsberg Mining District on the crest of the Jawawijaya mountain range in the highlands of Irian Jaya, Indonesia. The EESS was discovered in 1968 where it cropped out at an elevation of 4050 metres above sea level. The Ertsberg Mining District is underlain by siliclastic carbonate and siltstone formations of Jurassic to Tertiary age. The sediments have been folded and are cut by major bedding subparallel and crosscutting structures. Intrusion of a series of igneous bodies post-dates folding and faulting. These I-type intrusions are the source for the copper-gold mineralisation found in the Ertsberg Mining District. The EESS is hosted by carbonates of the Tertiary Waripi and Faumai Formations that have been altered to calcium-magnesium silicate skarn and is situated on the southern limb of a northwest-trending syncline. The EESS is an essentially vertical tabular body with a vertical extent of at least 1200 metres and a lateral extent of up to 1000 metres. The width of the EESS averages 200 metres and locally is in excess of 300 metres. The northeast (hangingwall) contact of the EESS is a skarn reaction front in sudden contact with barren marbles. This contact coincides with a zone of localised faulting and brecciation. The EESS is bounded to the southwest (footwall) by the Ertsberg Diorite, a 3.25 Ma old intrusive. The DOZ block cave operation extends from 3040 metres above sea level to a maximum of 3388 metres above sea level, has a length of 860 metres and a maximum width of 350 metres. The DOZ is a high temperature skarn with a prograde forsterite/diopside mineralogy whose protolith is the dolomitic Tertiary Waripi Formation. The principal retrograde alteration minerals include tremolite, actinolite, serpentine, talc and chlorite. Grade is highest where bornite occurs in large dense complex intergrowths with magnetite and anhydrite. Grade has been locally enhanced in the DOZ by a late-stage pyrite-chalcopyrite hydrothermal alteration event with associated brecciation. Ertsberg Diorite along the footwall of the skarn is also included in the reserve where it is mineralised endoskarn or has been mineralised by porphyrytic or late stage hydrothermal alteration. Formation of the EESS was initiated by contact metamorphism during the intrusion of the Ertsberg Diorite with later metasomatic alteration during both prograde and retrograde phases. The bulk of sulphide mineralisation formed late in the retrograde phase. The EESS is open along strike to the northwest and down-dip with on-going exploration of these areas. Current exploration is targeting both endoskarn and porphyry style alteration and mineralisation of the Ertsberg Diorite.

Jan 1, 1999

By T de Wit, S Meyer

The location of seismic events in mines is traditionally calculated based on the arrival times of P- and S-waves for a given velocity model (homogeneous or heterogeneous). This technique is successful when the sources of seismic events are sudden and localised (eg episodes of fracturing in solid rock or dynamic slip along a plane of weakness) and thus the radiated seismic waves have clear arrivals. In massive mining operations such as block caves, strong seismic signals often originate from the movement of loose rocks on the perimeter of the fracture zone. These signals are easily recordable but do not contain easily identifiable direct P- and S-waves, making the estimation of location through traditional methods more complicated. This problem has been approached by using a ‘brightness’ location method that estimates the origin of seismic waves based on travel times of envelopes of seismic energy. This tool is extended to be applicable in a heterogeneous velocity environment that now accounts for the presence of a cave or other strong velocity perturbations. The suggested method is particularly important when caving occurs in low-stress environments (eg close to the surface).CITATION:Meyer, S and de Wit, T, 2016. Location of seismic events associated with caving using brightness method, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 225–236 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

The ores described in this paper are from the two principal orebodies at Wiseman's Creek, a small village about 22 miles south-east of Bathurst in central-western New South Wales.The first official reference to mining at Wiseman's Creek is in "Mineral Statistics of New South Wales" of 1875, which reported that the Wiseman's Creek Copper Mining Company had proved a lode-later known as "North Wiseman's"-to a depth of 120 ft., where it was found to be 20 ft. wide. By 1876 the erection of a mill and smelting works had commenced, and the sulphide ore found to contain copper lead, zinc, silver and gold. Some oxidised ore was also being worked. Operations were, however, generally unsuccessful, and sporadic work up until 1907 produced only about 5,000 tons of ore. The other more important orebody of the locality-the Phoenix-was not opened until about 1895. By 1908, as reported by J. E. Carne, the shaft had been sunk 340 ft., with the extraction of both oxidised and primary ore. At the time of the slump in copper, pric'es in 1907 approximately 3,000 tons of, ore had been produced.Several smaller orebodies were discovered and worked during the same period as the North Wiseman's and Phoenix, but their output was more or less insignficant. THE OREBODIES AND THEIR GEOLOGICAL SETTINGIt is now impossible to examine the orebodies underground, but they appear to have formed a series of flat lenses, whose major axes were parallel to ,the foliation of the enclosing quartz-chlorite-muscovite schists. The largest ,of these lenses was worked as the North Wiseman's orebody, which was reported by Carne to vary in width from 1 ft. to 20 ft., and which probably extended discontinuously over a strike length of about 1,000 ft. The Phoenix orebody is stated to have varied from 1 ft. 6 in. to 3 ft. in width...

Jan 1, 1955

By K Ehrig, J Griffith

An extensive suite of elements are routinely assayed on all resource drill core samples to assist in deposit scale resource definition, local mine scale delineation of ore zones, and ore characterisation for the planning and scheduling of mining and processing of ores at Olympic Dam. This paper discusses a deposit scale geochemical relation that can be used by mine geologists to find more high-grade ore at the local mine area scale at Olympic Dam.A 3D grade shell representing 0.8 per cent Cu was created for a mine area using drill hole assay data. This defined the geometry of the ore zone. The Cu-grade shell was then overlain onto the existing resource block model to evaluate the relationships between the Cu-grade shell, copper and other elements. The strongest correlation was between copper and manganese. The block model showed a dramatic decrease in the concentration of manganese just below the below the Cu-grade shell.Several drill holes that intersected the Cu-grade shell were selected to evaluate the copper manganese relation at the drill hole scale. As expected, the individual drill holes displayed a strong inverse relation between copper and manganese. A geochemical footwall was then modelled representing 0.1 wt per cent Mn. Using both the Cu– and Mn-grade shells, several drill holes were designed/drilled and all hit high-grade copper.For the vast majority of the deposit the inverse relation between copper and manganese is valid; however, in areas with intense chlorite alteration (related to amounts of mafic to ultramafic rocks) this relation is not as strong, due to increased manganese in the rock mass. Even though using the copper manganese relation as a drill targeting method was not always as reliable in a few small areas of the deposit, it demonstrates the value of using existing assay data integrated with the resource block model to discover local mine scale geochemical relationships which can be used to more effectively design drill holes to discover high-grade ore at Olympic Dam.CITATION:Griffith, J and Ehrig, K, 2017. Using existing data to improve the delineation of ore at the Olympic Dam Fe-oxide Cu-U-Au-Ag deposit, in Proceedings Tenth International Mining Geology Conference 2017, pp 321–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By G J JAMESON

The flotation cell has undergone a number of changes since the process was first introduced in Broken Hill in the early years of this century. The development of the mechanical flotation cell is reviewed, followed by a discussion of more recent developments such as the flotation column, the air-sparged hydrocyclone, the Wemco-Leeds cell, the Bahr and Deister columns and the Jameson cell.

Jan 1, 1992

The Ministry of Commerce has been carrying out an evaluation of the resources of the Northwest Nelson region. In part this was to revisit the issues covered in the earlier proposal to close part of Northwest Nelson to mining under section 24 of the Mining Act (1971) initiated in 1990. In addition, the option of using GIS to integrate a variety of spatial data sets to aid policy formulation could be tested. The Northwest Nelson assessment would be a useful trial. The subsequent national park proposal provided a major impetus to the project and resulted in the scope of the study being broadened to include all energy and minerals resources.

Jan 1, 1993

By Bohrn W, Milionis K, Tessmer G, Reidetschlager J

The share of electric arc furnace based steel production is increasing - New technologies for the production of virgin raw materials for EAF production are under development and on the market - VAI has a strong position in the field of scrap substitution technologies with their COREX«-, COREX«-DR and FINMET«-technology. In late-1998 the steel plant SALDANHA was started up successfully. This integrated compact mill is using the COREX«-technology as hot metal and a combined DR-plant as DRI production unit. Also in 1999 the BHB FINMET« plant Port Headland went on Stream.

Jan 1, 1999

By T Howard, J E. Everett

BHP Billiton Iron Ore has replaced the conventional product quality control batch system at Yandi with the Continuous Stockpile Management System (CSMS) centred on a fully integrated æcontinuousÆ stockpile flow from mine planning through to port reclaiming. With increasing tonnage rates, tight operational coupling associated with the original batch system caused production interference which achieved final product quality but in an increasingly inefficient manner. This innovative approach places a continuous emphasis on product grade control and takes full advantage of the most appropriate blending opportunities of the mine to port planning and production system in order to reduce the natural variability of the ore to an acceptable level. To implement continuous control, product variability throughout the process is classified as long-term and short-term. Long-term variability is best controlled through the monthly mine planning process which determines monthly grade targets while taking into account optimum mine development. In the past, attempts to control long-term variability were made at the port through selective stockpiling and reclaiming which reduced operational efficiency. Short-term variability is best controlled around the monthly mine grade target by daily mine production scheduling, train sequencing, stacking into port stockpiles of appropriate size and systematical stockpile reclaiming. The implementation of the new system has maintained customer accepted shipping grades and has provided significant improvements in resource utilisation, operational efficiencies and costs.

Jan 1, 2002

By C Doblin

Any value addition to the mineral sands in the Murray Basin (Australia) will generate waste that needs to be disposed of safely. For example, conversion of ilmenite and synthetic rutile to titania (TiO2) pigment would generate large amounts of environmentally undesirable elements. Processing of U+Th containing zircon sands to zirconia or to higher purity zircon would generate a low-level radioactive waste. In this study it is proposed that one way to circumvent the waste problem could be to contain such waste in magnesium-based (Sorel) cements. Containment of waste in magnesium cements is an attractive idea especially for the mineral sand processing companies that could operate in the Murray Basin in the future, because the required magnesium oxide and magnesium chloride may be made cheaply from the saline waters encountered during mining operations. The magnesium cement production process is also far less energy intensive than the Portland cement production process. The results of this study indicate that mixing a waste stream with a slurry of magnesium cement before being discharged to the disposal area would contain the waste in a æconcrete-likeÆ structure, resistant to dispersion by wind and moderate rain. However, some loss of strength and increased leaching of impurities, Mg and Cl could take place in wet climate areas. Ongoing research is being concentrated to develop a new process for making water-resistant magnesium cement.

Jan 1, 2002

Laboratory flotation tests on sized fractions of a certain number of selected minerals with homologous fatty acid derivatives (i.e. sodium salts and amine acetates) confirm that the higher homologues are more efficient collectors than the lower. Tests were carried out on sized material and finer size fractions floated at lower collector concentrations.It is suggested that selective flotation is best achieved with the reagent which most readily floats the most friable mineral in the ore, and that grade of product will be improved with the lowest usable homologue.INTRODUCTIONFlotation of non-sulphide minerals with fatty acids as collectors is usually less selective than the flotation of sulphide minerals with xanthate collectors. It is common to use the gradation in collecting power of homologous series of xanthates, as well as the more specific effects of activators and depressants, to achieve the separation of sulphides.The original aim of the work was to ascertain whether sodium salts of fatty acids (anionic) and fatty amine aceta:tes (cationic) could be selected from a homologous series to achieve better selectivity in separation of nonsulphide minerals by flotation. Subsequently the importance of friability of minerals in selective flotation was observed and the aim was expanded to develop a more practical approach to the testing of ore.MATERIALS USEDMineralsA series of massive mineral specimens, as pure as could be obtained, was procured. The specimens were cleaned by removing extraneous material, and then crushed and dry...

Jan 1, 1965

The Development of a Non-Roasting Technology for Polymetallic Gold and Silver-Bearing Sulfide Concentrates Treatment

Sep 13, 2010