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By P M. Dight

Shotcrete usage in declines and developments has become pervasive as operators strive to achieve production improvements. Issues of mix control, fibreload, thickness control, temperature and curing conditions all play a part in the quality control. Often to overcome some of the quality control issues designers over specify the strength requirements in order to meet their operational constraints. Adherence to the standard civil testing requirements of 28 days moist cured at 21ºC without properly calibrating these results to the changing environment underground leads to contractual disputes. There are a number of standard tests specified including cylinder tests, cored tests, beam tests and round determinate panel (RDP) panel tests. The logistics of storing these samples and then transporting them to concrete testing laboratories without due regard to temperature changes with time can influence the results. All the samples can be readily handled by personnel except the RDP panel. The standard RDP panel is 800 mm diameter by 75 mm thick and requires an ITH machine at the mine and a fork lift at the laboratory to move it around. This paper will examine the possibility of a panel which provides scalable results to the standard RDP panel but can be easily handled by personnel and/or tested on site with suitable equipment. This allows for faster turn around and better quality control for the sample prior to testing. This enhances the identification of quality control issues at the mine and improves safety.

Mar 21, 2011

By A G McLean

This paper will first discuss the fundamental requirements for reliable discharge of backfill by gravity alone at high per cent solids. This discussion will include brief mention of the underlying principles of saturated solids flow contrasted to that of stirred tank or dilute discharge systems. Here the need to possess full knowledge of the flow properties of the stored material will be highlighted. In regard to attainment of reliable discharge it will he revealed flow from a backfill silo will only occur provided: ò the flowing material in the converging channel is yielding throughout; ò slip is occurring along the walls; ò an arched stress field is present in the vicinity of the outlet; ò the flowing backfill must be dilating to flow in response to the dilating stress field; ò sufficient dilation water is injected, in the hopper, to eliminate the formation of adverse interstitial pressure gradients; ò sufficient dilution water is injected, downstream from the hopper outlet, to generate a pumpable slurry of maximum per cent solids; ò the silo level must be sufficient to prevent the pump suction forming a rathole; ò the system must be configured and operated to generate stable discharge density; and ò the system must be configured and operated to minimise damage to the pump liners. In addition proper account must be made of the silo overflow weir and settling capacity to match plant throughput. Here opportunity will be taken to highlight the complexity of this multi-phase flow situation as well as the general yet paramount requirements for reliable solids flow. It will be shown that by proper attention to the multi-phase considerations gravity discharge of slurries as a consolidated bed with minimal water content is possible. Such high solids discharge results in greatly reduced demand for process water. In addition pumping costs are reduced as is the delay time associated with the mine drainage operation. Confirmation of successful applications will be highlighted by reference to several recent case studies. In the concluding phase mention will be made of the key yet very simple and effective operation techniques which enhance reliable Discharge.

Jan 1, 1998

By J F. Costa, A Grigorieff

Coal mining reclamation is a worldwide concern. This paper presents a Brazilian example where the economic aspects of reclamation are considered. The basic goal of the study is to transform the reclamation procedures into an economic process by integrating the use of land after reclamation and developing profitable post operations. Some of the activities considered in this case study include: using of the coal pit as a landfill, considering appropriate landfill design and construction; using the area for forest development; and developing grassland, forests of native species and the construction of ponds for fishery. This study will conclude that the mined area is: capable of storing large quantities of waste at a competitive cost and at a low environmental risk; commercial forest development is economically feasible; and the lakes and other reclaimed areas can be integrated into the landscape creating a fresh water supply and an area to raise cattle.

Jan 1, 2005

By Hayward N, Sutherland D, Wilkie G

A pilot plant study has been made of the liberation characteristics of a nickel ore under different milling conditions. A series of runs were made ranging from fully autogenous grinding to semi-autogenous grinding with a ball load of 8%. The mill products were sized and assayed then analysed by QEM4SEM. This enabled a full liberation analysis to be carried out to see whether the autogenous grinding leads to improved liberation by promoting selective breakage. Though it is frequently claimed that fully autogenous grinding yields superior liberation this could not be detected in the present study.

Jan 1, 1991

Early in 1950 a new laboratory was set up to deal with problems in mineragraphy, petrology and metallography. This paper describes the equipment, the organisation and association of the laboratory with the various departments of the company, the work that has been done and future plans.At Mount Isa it was soon realised that the microscope would play a most important role in mineral dressing problems and aiding geological research.As early as 1928, R. J. Colony submitted a petrographic report on Black Star ore for Consolidated Limited; much later, in 1934-5 Dr. Grondijs published for Mount Isa Mines Limited a preliminary study of the Mount Isa orebody, followed by a mineragraphicinvestigation of mill products, and in 1937 a Study of Mount Isa Ores by H. GrondIjs and C. Schouten appeared in Economic Geology, for June-July. Other papers dealing with the petrology and mineragraphy of Mount Isa ores are appended at the end of the paper.The mill research metallurgical staff has endeavoured to incorporate mineragraphy in solving milling problems and determining the effectiveness of laboratory as well as examining minerals sent in by the geological department.For many years the amount of equipment available was limited and much of it was locally made or improvised. An improvised briquetting machine, and grinding and polishing lap gave moderate results in conjunction with an old, but serviceable, Leitz microscope. However, for more detailed and accurate work not possible with improvised equipment, many mineragraphic problems were sent to specialist in.

Jan 1, 1953

By B Murphy

Seeking to reduce the likelihood of uncontrolled personnel entry into the operating footprint of a dragline, Coronado Global Resources initiated a review of proximity detection systems currently available and equipment interactions in and around dragline operational areas. At the time of the assessment, there were no established personnel proximity detection systems in compliance with functional safety standards for large machinery in Australia. Our primary objective was to guarantee a functionally safe outcome, particularly by implementing a performance-level-rated system in accordance with AS4024 (Safety of Machinery series of Australian Standards). Applying appropriate detection technologies, the goal was to reduce the residual operating risk for machine-to-machine and machine-to-personnel interactions. A comprehensive analysis of available or in-development technologies was conducted, and a layered approach (demonstrated in Figure 1) was adopted to achieve the desired risk reduction by segregating the sensing zones into distinct areas using diverse and disparate technologies consisting of radar (short); light detection and ranging (LiDAR) (medium); and optical (long). To address the potential limitations of each technology, overlapping layered sensing zones were designed. With LIDAR and optical using two distinct artificial intelligence (AI) systems to classify detections, these were specifically trained to handle the unique environments of a mining operation.

Sep 1, 2024

By J C. Koppe, L Vieira

One common problem for blasting in iron ore mines with significant weathering is the occurrence of large blocks of hard rock mixed with softer material. This situation causes a problem for blasting design and sometimes produces large boulders of rock that require a secondary blasting, as well as excavation difficulties. To minimise this situation, geophysical techniques were used to identify the hardest material amid the weathered material. To study the problem, seismic, ground penetrating radar (GPR), electrical resistivity and induced polarisation (IP) methods were used in an intensely weathered Brazilian iron ore deposit. The methods of GPR combined with IP, resistivity and seismic showed to be effective in modelling the contrast among hard, friable materials and soil. The results were used to improve the geological model and create more favourable conditions for the subsequent blast design. The blast design based on geophysical/geological models resulted in significant improvement in the fragmentation of the iron ore. This was achieved by the adoption of a specific drilling pattern for a given geological situation. With the new specialised blasting design the formation of boulders was eliminated.CITATION:Vieira, L and Koppe, J C, 2015. Geophysical techniques applied to blasting design, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 289–294 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M Robertson

3D photogrammetry is a powerful tool for data capture and interpretation, utilised at all Australian underground MMG sites. In personnel constrained mines, 3D photogrammetry can free up personnel time, improve data quality for resource modelling, as well as benefit other mining departments.At Rosebery one of the challenges faced by geologists was no longer data capture but, rather, avoiding paralysis by analysis from the sheer abundance of information currently available to the department. Although the data had been interpreted, the structural model was cluttered; the geological block model was not incorporating any geological domains captured by 3D photogrammetry, nor was it being utilised by other departments such as geotechnical engineering.The geology department is now focusing on utilising all the interpreted data gained from each photograph heading into an uncluttered, easily understandable model for geologists and other mining departments.Our solutions involve integrating the Leapfrog modelling suite into the process, streamlining the structural model, tailoring the data interpretations for future updates of the block model and training other departments to improve utilisation of the interpreted data. This process also uncovered other benefits for near-mine exploration, and improving our understanding of the deposit’s origin.CITATION:Robertson, M, 2017. The practical use of underground 3D photogrammetry data at MMG Rosebery polymetallic mine, Tasmania, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 409–412 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By K Ehrig

Two irrefutable facts in geology and metallurgy are: ore deposits are comprised of variable mixtures of minerals which are systematically distributed throughout the deposit, and mineralogy exerts the primary control on metallurgical performance. If the distribution of process critical minerals can be quantified and mapped, then a logical assumption is that metallurgical performance can be predicted across the deposit.Olympic Dam is a +9 billion tonne Fe-oxide Cu-U-Au-Ag deposit which is hosted entirely within a magmatic-hydrothermal breccia complex consisting of over seventy ore and gangue minerals. Each has a unique set of metallurgical performance properties. Fortunately, 15 of the 70 minerals accounts for >98 per cent of the total rock mass.The mineral mapping journey commenced in the early drilling days shortly after the discovery of Olympic Dam in 1975. Geologists quickly recognised that the copper-iron sulphides had a predictable zoned distribution. However, geological models reflected the presence or relative abundances, not quantitative concentrations, of the minerals. This type of mineral mapping remained relatively unchanged for ~20 years and was of limited use outside of geology.Several things changed during the mid-1990s: assaying costs decreased significantly, instruments capable of automatically measuring mineralogy became readily available, the recognition of two quantifiable relationships at OD (ie mineralogy is a function of chemical composition (ie assays), and metallurgical performance is a function of assays, mineralogy, texture and process conditions. The linkage of metallurgical performance to mineralogy and mineralogy back to assays allows for every assayed sample in the resource model to be assigned mineral concentrations and metallurgical performance predictors. At Olympic Dam, block models (ie 3D maps) are routinely produced for 27 elements, density, 15 process critical minerals and greater than 50 metallurgical performance variables. These geometallurgy-enabled resource models are used for mine planning, process plant design and process optimisation studies. *This is an abstract only. No paper was prepared for this abstract.*

Sep 5, 2011

The purpose of this study was to investigate the effectiveness of froth fl otation for the recovery of gold from the gravity tailing stream of the former Lihir Gold Limited (LGL) operation in Ballarat. The P80 of the tailings was determined by screen analysis as 1 mm, with test work conducted on as received material along with samples ground to P80 sizes of 47, 78 and 134 microns. Laboratory scale batch flotation tests were conducted at both natural and elevated pH to investigate the impact of pyrite depression on gold recovery. Results indicated that although an increase in grade from approximately 0.7 g/t to 3 g/t was achievable at a natural pH and a P80 of 134 micron, gold recovery was low at just 35 per cent. Finer grind sizes were found to have an adverse effect on both grade and recovery. Future efforts will be focused on the sub 310 micron size fraction of the tailings, which was revealed to contain approximately 85 per cent of the available gold and may be amenable to cyanidation or ultra-fine gravity treatment.

Aug 1, 2010

By P Aguilera, C Guerrero, M Tucker

With the advent of Electronic Detonator Systems in the global mining industry, as well as the development of high precision pyrotechnic delays, the measurement and analysis of delay performance (usually measured in terms of dispersion about a batch mean û precision, and the deviation of that mean from the nominal detonation time û accuracy), has become an important issue. Through the non-conventional use of existing Velocity of Detonation (VoD) measurement technology, it has been shown to be feasible to measure the precision and accuracy of delay detonator series connected in the same manner as a typical open pit bench hook up. This paper describes the work undertaken to compare and contrast performance results obtained using a range of instrumentation including High Speed Video (HSV) filming, digital counter timing using a Hewlett Packard Universal Counter and a digital VoD measurement device. The results obtained demonstrated the practical feasibility of using the latter technology in order to obtain relatively large amounts of data in a time-efficient manner, with a precision of better than 0.5 microseconds, if required. The results also confirmed the close statistical agreement obtained between the three forms of performance measurement, therefore permitting the substitution of the VoD measurement technique for the more capital cost intensive HSV technique and the slow, sample-by-sample HP Universal Counter method. This paper describes the methodology applied and the results obtained.

Jan 1, 2004

By H Wang, D Wang

Mine dust is the most serious occupation hazard in coalmines. And many coal workers suffer from pneumoconiosis because of long-term inhalation of respirable dust. Reducing the dust concentration of workplaces by effective technical means is an important way to prevent coal worker’s pneumoconiosis (CWP). In order to overcome deficiencies in existing dust control technology for underground mining, especially the disadvantage of water spray technology mounted on roadheaders or continuous miners, the authors developed an integrated dust suppression technology utilising foam for fully mechanised heading faces. This paper presents an overview of the principles, materials, equipment and application of this technology. Among these, a jet type foaming device and a green foaming agent were developed, which can realise the goal of efficient preparation of foam. In addition, an arc fan nozzle used for foam spraying was invented, which can effectively cover and enwrap the dust produced by the roadheader at the cutting point and achieve the goal of efficient utilisation of foam. This dust suppression application of the proposed foam technology was investigated on fully mechanised heading faces. The results show that the dust concentration was cut down significantly with a dust suppression efficiency of greater than 85 per cent, an increase of over 30 percentage points compared to the water spray system. This study demonstrates that this foam technology can play an important role in dust suppression on fully mechanised heading faces, which provides an important method to improve the working environment and protect coal workers’ health.CITATION:Wang, D and Wang, H, 2015. Technology of dust suppression by foam for fully mechanised heading face, in Proceedings The Australian Mine Ventilation Conference, pp 177–182 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

For an exploration area with a predetermined grid of data points, a construction is given for elementary blocks which subdivide the entire area without omission or overlap, and with the property that each data point is situated at the centre of its corresponding block. The construction has a useful optimal property, and more importantly avoids an error which has been made recently in more than one publication.

Jan 1, 1985

I've talked a number of times in the past year or so to audiences like today's about culture -about thinking of it, understanding it, respecting it. So, rather than talk just yet about your laws for mining on Aboriginal land and the successes some of us and some of you have been able to achieve, I'd like to first of all talk about cul- ture as I understand it. Anyone who proposes any kind of development on Aborigi- nal land needs to have some basic understanding of what we, the traditional owners of that land, are about. Without that under- standing, you will find difficulty in coming to terms with us. Many people have experienced this difficulty and, unless we can do something about it together, many more will continue to find it.

Jan 1, 1988

The paper focuses on how rock bolts are loaded in different rock masses, as well as in pullout tests. Three analytical models for rock bolts are presented in brief, one for bolts in continuously deformed rock masses, one for bolts in blocky rock masses, and one for bolts in pullout tests. The bolt models are used to interpret measurement data for rock bolts from three sources and to help specify the modes of axial load in the rock bolts. It is found that in continuously deformed rock formations fully coupled rock bolts have only one axial stress peak. The position of the axial stress peak moves towards the far end of the bolts with increasing rock deformation. In blocky rock masses several axial stress peaks may appear in the rock bolt. The position of this kind of axial stress peak does not change during the entire loading process. For rock bolts in pullout tests, decoupling of the interface always occurs first at the loading point. The decoupling front moves towards the far end of the bolt with an increase in the applied pull load.

Jan 1, 2000

By S Jayakumari, E Ringdalen, V Canaguier

Silicomanganese (SiMn), containing approximately 16–30 per cent Si, is produced in submerged arc furnaces using various Mn sources and quartz as the primary raw materials, along with fluxes and reductants. In the high-temperature zone known as the coke bed, a silica-rich slag is formed. SiMn is produced through the reduction of SiO2 from the slag. Dissolution of quartz into slags with different compositions, the primary slag formed from the Mn sources and flux before any MnO reduction occurred, representing conditions at the top of the coke bed, and dissolution of quartz into a partially reduced slag to simulate conditions inside the coke bed has been investigated. Experimental investigations were carried out to study the dissolution of quartz particles of varying sizes, 5 mm and 25 mm in synthetic slags with different compositions at temperatures between 1400°C and 1600°C, with varying holding times. Observed results are compared with liquidus compositions and equilibrium phases for original and formed slags. Particle size has been shown to be of little importance for the dissolution. Quartz dissolved more easily in slag at top of the coke bed than slag in the coke bed. Complete dissolution was observed after 30 mins at 1600°C in all cases, but not after 0 mins.

Jun 19, 2024

By J H. Kyle

Cyanide is a significant cost in gold processing, as well as an environmentally sensitive issue. It has been suggested that precipitation of cyanide from leach liquors as copper-iron-cyanide compounds such as Cu2Fe(CN)6 may account for part of the total cyanide consumption. This may be especially true for ores that are rich in both copper and iron minerals. Ammonia addition has been shown to decrease the cyanide consumption by copper. Cu2Fe(CN)6.xNH3 precipitates have also been postulated to form during conventional cyanide detoxification processes, using oxidants such as SO2/air, with ammonia arising as a breakdown product from the oxidation of free cyanide. The present work has examined the conditions under which such precipitates may form, particularly in gold plant process and detoxification liquors. Ammonia and pH were found to have a large effect on the extent of precipitation. The compounds that were formed were found to comprise mainly Cu2Fe(CN)6.7H2O, as well as a range of NH3-bearing variants. The stabilities of the various precipitates are important from an environmental perspective. The long-term stability of copper ferrocyanide precipitates in tailings dams may be a problem under alkaline conditions and when some free cyanide is present, elevating the measured total cyanide in solution significantly. Case studies including data from actual plants are also considered, and the importance of these effects is reaffirmed from these results.

Jan 1, 2000

By Bulters J, Sheppard I

Two blasthole density logging programmes have been conducted on the Mt Whaleback iron ore mine to evaluate the use of this type of logging as an aid to blast pattern design. The first programme also involved the setting up of a Density Test facility with which to calibrate the density probe. The programmes indicated that about 22-23 blastholes can be consistently logged per day at a cost of $1.30 per metre. Even though this is only half the rate required to log the average number of blastholes drilled daily on Mt Whaleback, testwork indicated that no significant loss of accuracy results if only half the holes in a pattern are logged. The major results of the programmes were: 1. The density range for black pyritic Shale is 2.2-2,9 g/cc. 2. The density range for soft to medium hard BIF is 2.1-3.0 g/cc. 3. The density range for hard BIF is 3.0-3.6 g/cc. 4. The front row blastholes show consistently lower densities than the main body holes due to blast damage. 5. A low density zone extending to a maximum depth of 6 m occurs at the top of most blastholes and results from blast damage from the bench above. These density results have been used to implement savings in drilling and blasting via pattern expansion and charge optimisation of blastholes. Eight ore

Jan 1, 1986

By J Berg, M Hahn, R Winkel

Imaging sensor systems designed for the mining and minerals industry incorporate different physical measurement technologies that can be used to detect the machine environment, such as laser, ultrasonic/sonar, video and RF-sensors. The underlying physical measurement principles cannot be employed in most applications near the face without regular maintenance due to the harsh environmental conditions like dust, dirt or moisture. However, that is the area, where imaging sensors are most valuable to the machine operator. In the domain of 2D radar sensors these have been either restricted by the angular coverage area or by limited adaptability of signal processing algorithms. The unique full digital solid state design will establish a generation step in mining applications.In order to fill this gap of terrain imaging sensors, the Institute for Mining and Metallurgy Machinery (IMR) of the RWTH Aachen University, in cooperation with the radar company indurad, developed an imaging sensor based on radar technology employing the digital beam forming (DBF) concept. Through multiple transmitting and receiving antennas the sensor delivers high accuracy range and angular information. Using adaptive digital signal processing with multiple imaging algorithms and target detection routines, data of the surrounding environment can be used to enable automation functions in mining.A comprehensive range of radar scans in different environments have been evaluated and benchmarked by using laser scanners. Accuracy measurements in range and angular direction have shown minimal differences. Experimental measurements have been performed at slopes, on conveyor belts and hot cement clinker silos. The experimental system uses a frequency modulated continuous wave (FMCW) front-end combined with a processing unit for signal analysis and target detection.

Sep 26, 2011

By Y Chung, B Choi, H Lee

Numerous studies have explored refractory corrosion in the presence of slag and/or metal, utilising the Finger Rotating Test (FRT). Recent experimental results revealed that corrosion initially increased with rising rotation velocity but was then suppressed above a critical rotating speed, under conditions involving a two-liquid solution of slag and molten steel. This phenomenon indicated that the liquid/liquid interface movement occurred during spindle rotor. However, understanding of the phenomenon, known as the rod climbing effect, remains inadequate in the case involving slag, molten steel and refractories. To gain deeper insights, a simulation experiment was conducted on the phenomenon using silicon oil/water and the phenomenon was analysed using computerised simulation software (Ansys Fluent). Experimental modelling demonstrated that interfacial movement occurs even at low rotation velocity, as low as 200 rev/min, when the viscosity of silicone oil is at 100 cP. Computational analysis utilising the Volume of Fluid (VOF) method and a realisable k-ε turbulence model elucidated that interface elevation during rotor rotation arises due to viscosity disparities between the two fluids. Furthermore, this movement is more pronounced when the viscosity difference is lower. Additionally, the study findings suggest that higher density differences between two liquids suppress the phenomenon of interface movement.

Jun 19, 2024