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By M Chen, G H. Wang, J R. Zhou, P Yan, W B. Lu

Blast vibration analysis is one of the important topics in the control technology of blast vibration damage. Nowadays, blasting vibration safety standards are based on both the particle velocity and the frequency of vibration and they have been adopted widely and internationally. However, the analysis on vibration frequencies is less studied compared to investigations of peak particle velocity. For the vibration induced by a spherical charge in a viscoelasticly infinite rock mass, an expression of vibration spectrum taking into account the damping effect of rock mass is inferred. Then the attenuation laws of dominant frequencies and centroid frequencies are compared theoretically. For the case of cylindrical charge, dynamic finite element method (DFEM) software of LS-DYNA is employed to analyse the attenuation laws of characteristic frequencies. The research demonstrates that, no matter whether it is a spherical charge or a cylindrical charge, there is a local mutation or fluctuation at some distance when the blast proceeds, while the centroid frequencies conform to a smooth attenuation law. Both the multipeaks structures of vibration spectra and the decay rate difference between high- and low-frequency components contribute to the mutation or fluctuation investigated in this study. Additionally, an increase in longitudinally sonic velocity or the quality factor of rock mass produces an increase in the vibration frequencies, whereas an increase in blast source diameter or the rise time of blast load produces a decrease in vibration frequencies from a spherical charge. In borehole blasting, there is a positive correlation between the vibration frequencies and charge diameter, whereas there is a negative correlation with charge length. And altering the initiation plan will change vibration frequencies to various degrees. Finally, theoretical analysis results were validated by the empirical data from field experiments of Fengning pumped storage power station.CITATION:Zhou, J R, Lu, W B, Chen, M, Yan, P and Wang, G H, 2015. A further study on the attenuation laws of blasting vibration frequency, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 673–682 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Direct measurements of liquid contents in foams obtained from (x-terpineol a-T) n-pentanol (AmOH) and n-octanol (OctOH) solutions were carried out using a column of special construction. The column enables to determine the liquid contents by cutting-off foam layers of various thicknesses and measuring amounts of liquid contained in the cut-off foam layers. Liquid contents in the whole foam layers, in the top foam layers of thickness 14 ¦ 1 mm and distribution of water alongside foam height were determined. The average liquid contents were high and reached a level of 30, 35 and 40 per cent for foams formed from cc-T, AmOH and OctOH solutions, respectively. The liquid contents in the top foam layers were much smaller. They were of an order of five per cent for a-T and AmOH and 12 per cent for OctOH. On the basis of the liquid distribution alongside foam height some practical conclusions concerning possibilities of minimising amounts of liquid contained in the collected concentrate are presented.

Jan 1, 1993

As a minerals company, obtaining the appropriate consents under the Resource Management Act 1991 and getting permits granted for exploring, prospecting and mining under the Crown Minerals Act 1991, is necessary for actively exploring and mining in New Zealand. But the essential mix of ingredients for a viable and healthy Industry go way beyond this.   In the short term, an individual company seeking to operate on or within the Crown minerals estate of New Zealand must chart a course through the requirements raised by new cornerstone legislation, the Resource Management Act, the Crown Minerals Act and, the Conservation Act 1978 (where the minerals sought coincide with this estate).   However, this paper suggests that in the longer term for individual operators within the Industry and for the Industry at large to remain viable and sustainable and for New Zealanders to continue to enjoy its benefits, much more is required. Not least of which is a better balancing of competing uses and attitudes, which will require an opening of minds, a change in mindset, topped off with those two most essential of ingredients advocacy and leadership.   New Zealand has undergone massive restructuring in the last 15 years. Is it complete? Have each of its fronts evolved to the end point which was envisaged by the designers of the regime? What are the advantages? What is left to be done? What are the impediments from an incomplete transition which are left to either dog the Industry or remain as a challenge to be removed to ensure the Industry's smooth sailing into a prosperous and environmentally clean and friendly future? A future wherein an educated and understanding public welcome and are proud of the Minerals Industry to whom they owe the standard of living which they enjoy.   This presentation will examine the role of the New Zealand Minerals Industry Association (NZMIA) in paving the way for an optimum operating environment in which to couch a healthy industry into the future.

Jan 1, 1997

By P C. J Blackney, I M. Glacken

Spotted Quoll is a massive sulfide nickel deposit located in the Forrestania greenstone belt in the Archaean Yilgarn block in Western Australia. Discovered in October 2007, mining has progressed from open pit to underground and currently uses longhole open stoping with paste fill as the primary stoping method. Immediately prior to 2019, the Mineral Resource estimate (MRE) was defined by a single grade domain of nickel greater than or equal to 0.8 per cent, irrespective of the host lithology, a legacy of the original ore wireframe being built using explicit methods. While a number of obvious structural offsets were honoured in this nickel grade domain, only one modelled fault was used to undertake domaining of arsenic. From 2019 onwards, implicit modelling in Leapfrog Geo™ was used to construct a mine-scale geological model, which triggered the definition of a high-grade core of massive/matrix nickel sulfides surrounded by a low-grade halo of stringer/disseminated nickel sulfides in the surrounding rock. As part of the evolution of the geological model and with the aid of Seequent Central™ to allow collaboration between site-based mine geologists, Perth-based resource geologists and Melbourne-based consultants, a detailed review of the structural mapping was carried out as additional information from underground development became available. This allowed numerous faults and shears to be identified – particularly in the lower half of the mine. These were used to define further structural domains and to refine the understanding of the nickel and arsenic grade distributions in the mineralised envelope. The increased definition to the domains provided by the geological model resulted in a significant improvement in the accuracy of the Mineral Resource estimate, as measured by reconciliation using voids of the mined stopes determined from the cavity monitoring survey (CMS).

Mar 22, 2022

A viable flow sheet of the sorption-flotation technology for gold recovery from low-grade ores and concentrates using powdered activated carbon modified by organic compounds as the sorbent-bearer has been developed. The powdered activated carbon, with high kinetic ability and sufficient specific area, was selected as the all-purpose gold cyanide complex-bearing sorbent which is active during flotation. To improve carbon adsorption capacity and to provide the required floatability its porous structure was filled with a quaternary ammonium compound which can extract gold cyanide complexes and render additional flotation properties to the carbon. To optimise the process and to simplify the layout, adsorption and flotation processes were carried out simultaneously in a mechanical flotation cell. The proposed technology was used for extended and pilot-plant tests of sorption-flotation gold recovery from 0.6 g/t Au final tailings and 2.0 g/t Au gravity tailings. The extended tests were carried out on Taseevskaya (Chita Region) flotation tailings, whereas pilot-plant tests were conducted on Kommunarovskaya (Krasnoyarsk Region) gravity tailings passing to cyanidation, followed by processing with filtration technology. Additional gold recovery from Taseevskaya final flotation tailings was 50.8 per cent. Gold recovery from Kommunarovskaya final gravity tailings was 92.5 per cent. Compared to the complete sludge process conventionally used at the plant, gold recovery was increased by 7.5 per cent due to lower gold losses in the liquid phase and conversion of the refractory non-cyanided metal into a carbon concentrate. This paper presents the experimental results of gold adsorption onto powdered activated carbon modified with quaternary ammonium compounds (sorbent-bearer) as well as sorbent-bearer flotation with various collectors from cyanide solutions and pulps.

Jan 1, 2005

By F H. S dosSantos, R L. C Santos

The main objective of this work was to develop, at a laboratory scale, a process for treating residues from the settling stage of water treatment so as to remove and recover the aluminium as sulphate. The chemical analysis of residues from different water treatment plants indicated that the aluminium content varied from 15 to 20 per cent w/w. By using the appropriate experimental conditions, it was found to be possible to leach most of the aluminium content. The pH value of the recovered water was suitable for it to be recycled to the water treatment process and the residue appears to be suitable as raw material for bricks. The process developed contributes to the sustainability of the water treatment process.

Jan 1, 2002

By Motyka J, Adamczyk AF, Witczak S

A case study of migration of a paper factory fluid wastes, on the distance of 5 km from an underground disposal site to an ore mine is presented. The ore mine in question, situated in SW Poland is pumping 3.5 m3/s (ca 300 000 m3/day) of groundwater, producing a cone of depression about 150 m deep and several kilometers wide. The migration of wastes (pollutant) occurs within the carbonate karstic aquifer of Triassic age. The aquifer is about 100m thick and is characterized by the coefficient of hydraulic conductivity equal to 8 m/day on the average. The results of systematic measurements carried out for 13 years enabled to estimate the mean breakthrough curve of the pollutant. On this basis and taking into account the coefficient of hydraulic conductivity as well as the mean hydraulic gradient between the disposal site and the ore mine, the migration parameters of the polluting material, i.e. the real flow velocity, the effective porosity and the longitudinal disper- sivity have been calculated. As the measurements considered a long migration distance of the pollutant, the obtained hydrodynamic dispersion constant (dispersivity), in the authors opinion, is reliable enough to be applied for regional groundwater calculations, regardless of the "scale effect".

Jan 1, 1988

By Kennedy G. L, Evans D. G

The development of the carbonization of brown coal briquettes to produce a hard char suitable for use in place of imported hard coke has continued in Victoria, and an experimental carbonization plant has recently been commissioned at Morwell by the Gas and Fuel Corpora.tion to assess the prospects for the commercial production and marketing of hard char in Victoria. The char offers advantages in its very low ash content and its uniform lump size, while the indications are that it could be marketed at a price competitive with that of imported hard coke. The hard char is unique amongst metallurgical fuels in combining a high reactivity with high physical strength, and research by the University of Melbourne into its utilization in foundry cupolas for melting iron has shown how modifications could be made to take advantage of these properties. An 18 inch experimental cupola has been built to test in practice the predictions made from this fundamental research.INTRODUCTIONSteady development has continued in Victoria from the promising laboratory researches at the University of Melbourne which were reported to the 1955 Annual Conference of The Institute (Worner, 1956). This work had shown that a hard lump char could be produced by the high temperature carbonization of standard industrial briquettes by careful control of the heating conditions, and that the special briquetting techniques adopted in Germany were unnecessary with Yallourn brown coal. Continuation of this research has led to the refinement of carbonization techniques and has increased the strength of the char until it has equalled that of conventional metallurgical cokes.

Jan 1, 1960

It is self evident that in many cases mining disrupts communities, however, community reaction to mining varies enormously. This is due to a whole host of factors, some physical, some financial, some political and some a direct result of the projected mining company attitude towards the community at large. Physical and political factors are increasingly being dealt with realistically and financial aspects are to a significant extent determined by profit margins. If the acceptable profit margin canÆt accommodate all necessary costs (which now includes a variety of community considerations unheard of even a decade ago), then the project is just not viable. Despite major commitments now made by many mining companies to their affected communities, corporate attitudes, and their projection, remain as the most outstanding factor in mining project development where real gains can still be made in effectively reducing social risk. This paper addresses both international and domestic experience gained in managing this aspect of mining development risk, including initiatives implemented by multilateral institutions.

Jan 1, 2003

Knowledge of true block grades is obtained from a mathematical model of an orebody, simulated with sample grades normally distributed and spatially correlated according io a spherical semi-variogram model.The superiority of kriging to the polygonal method of estimation is demonstrated on this modelled deposit by comparing the true values with the kriged and polygonal estimates obtained from sampling the deposit. Finally, selection of blocks of the deposit on the basis of the estimated values, shows that if kriging is used, what is predicted is largely mined, whilst if the polygonal method is used large biases can occur depending on the position of the cut-off grade.

Jan 1, 1978

Real-Time Integration of Mining and Metallurgical Information for Efficient Use of Energy and Water

Sep 13, 2010

By M Camarda, A Pirson, F Vasconcelos, J Mesquita

ArcelorMittal Prijedor is a goethitic iron ore mine located in the north-west of Bosnia and Herzegovina, which mainly supplies ArcelorMittal’s European subsidiaries. Annual production of the asset stands at the level of 1.5–2.1 million tons of iron ore product which is sent to ArcelorMittal Zenica steelmaking plant. Two types of products with approximately 50 per cent Fe are generated in Prijedor through a process composed by crushing, screening, and magnetic separation stages. Within this process one of the tailings produced is called ‘ultrafines’. The ‘ultrafines’ product corresponds to the desliming hydrocyclones overflow in Prijedor plant, which is classified in a size fraction below 25 μm and corresponds to about 5 per cent of feed. This material is richer in iron than the coarser size fractions of the ore but do not present a good performance in concentration processes. In this way, several studies have been carried out during the last years to find solutions to use the ‘ultrafines’ material without success. In this context, the possibility of dehydroxylate the goethite contained in the material transforming the mineral into hematite and thus increasing the iron grade of the final product was investigated. During the research, several dehydroxylation tests with different temperatures and time of exposure were performed. Using dihydroxylation process at temperatures higher than 800°C it was possible to produce a material with 43 per cent Fe from the original 39 per cent Fe ‘ultrafines’ sample. In addition, the dehydroxylation tests confirmed that goethite becomes completely transformed into hematite at 400°C (with an exposure time of 60 mins) and material is completely sintered at 1200°C. A simulation study based on dehydroxylation tests results showed that it would be possible to use a ‘ultrafines’ product with Fe grade higher than 45 per cent to produce a material with 50 per cent Fe through a complete dehydroxylation process.

Sep 18, 2023

ALTHOUGH it has been a matter of about one hundred years since the idea of the internal-combustion engine entered the mind of the inventor, the practical application of its use was not attained till 1860, when Lenoir produced an engine similar to the ordinary highpressure steam engine, with the valves arranged to admit the explosive mixture and the discharge of the exhaust gases. In this case no attempt was made to compress the gas before ignition, as it was then considered that the explosion under these conditions had a detrimental effect, inasmuch as it would act as a sudden blow to the working parts. Indeed, he went so far as to inject steam and water sprays to reduce the explosion.Under these conditions the consumption of gas was exceedingly high-about 106 cub. ft. of coal gas per b.h.p. per hour but the mechanical effect showed that the engine ran in every respect as smoothly and quietly as in best steam-engine practice.The extravagant consumption of this engine was clearly pointed out at the time by Gustav Schmidt in a paper before the German Society of Engineers, wherein he states :-" The results would be far more favourable if compression pumps, worked from the engine, compressed the cold air and cold gas to three atmospheres before entrance into the cylinder. By this means a greater expansion and transformation of heat is possible."

Jan 1, 1912

By Y Zhou, Y Liu, J-P Yang, P Wang, K Hu

"Large-scale mine reclamation has taken place recently in response to the implementation of mining regulations in China. Effective monitoring of the progress of reclaimed land is a critical procedure to assess the quality of reclamation program and to ensure that mining enterprises fulfill their reclamation responsibilities. The present paper reports a preliminary study that examines the situation of mine land reclamation monitoring. Based on the monitoring, some general requirements for mined land reclamation have been proposed, including: the monitoring should be systematic and comprehensive the monitoring should be adapted to specific local conditions the monitoring should be reasonably optimised via scientific methods and technology the monitoring should stick to a variety of national technical criteria.The aim of land reclamation monitoring is to evaluate changes of critical indicators closely reflecting the development trend of the reclaimed mined land, to develop or improve the criteria and technical parameters specific to the site, and to prevent secondary environmental degradation. Based on these requirements and aim, the monitoring should cover the progress of reclamation, establishment of vegetation and plant community development; and recovery of land and water quality in the reclamation area. Regulatory measures are proposed which would improve the work of mine reclamation monitoring in terms of regulation, organisation and financial support.CITATION :Wang, P, Yang, J-P, Zhou, Y, Hu, K and Liu, Y, 2012. The primary framework for the mechanism of the mine reclamation monitoring in China, in Proceedings Life-of-Mine 2012, pp 47-50 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

Ventilation characteristics of a three h -nc longwall development panel in a 1/100th tale hydraulic model using dispersion mechanics are the first applications of its Find in ventilation. Dispersion mechanics gives additional and important ventilation parameters such as degree of mixing, bypassing, -ecirculation etc. These are not obtainable the traditional pressure-volume methods. Experimentally, the model work investigates entilation characteristics of different stopping layouts, including leaky stopping,, cut-throughs and return roadway, brattice tyre ventilation and the effects of flow rate reduction on air distribution in the headings. Additionally, a model of methane generation at the face provides results used to calculate the dispersion characteristics in the return airways. It is concluded that the model resui,s -trongly suggest that dispersion mechanics could be applied to mine ventilation surveys to provide quantitative flow pattern data and details of effective dispersion '?_C!,r riro ò `b' eritilat.ing air.

Jan 1, 1983

By P Benjamin, H Bohannan, C Farr

Geoffrey Blainey's historical account of the mining activity on the west coast of Tasmania, æThe Peaks of LyellÆ documents the changes over 130 years of activity in the region. Commissioned by the Mount Lyell Mining and Railway Company, emphasis is placed upon the development of the Mount Lyell Mine in Queenstown. Chapter 19 æWidening HorizonsÆ details the review the Mount Lyell Company undertook in 1904/05 to ensure the future of the operation, following the pessimistic outlook regarding diminishing reserves and poor grade ore. The analogies documented between the Mount Lyell Company at that time, and Gold Mines of Australia 90 years on are remarkable, with both companies demonstrating a commitment to the Mount Lyell area through active exploration, the proactive search for alternative technology and the recognition of the valuable human resource. As Blainey writes (Blainey, 1993), æwith its expanding chemical works, its huge Tasmanian mines, its railways and smelter, its coke works and its mine crusade, Mount Lyell was probably one of the nation's five great industrial companies in 1906 or 1907. This brief phase of industrial and mining expansion had its seed in the threat of extinction . . .Æ After a number of reprieves, the Mount Lyell mine did stop production in 1994, but that only provided an impetus for a review and rebirth.

Jan 1, 1998

By B P. Voutharoj, R A. Dutch, M Paknezhad, T Ostersen

With the proliferation of new sensor technologies, acquiring multiple data sets over the same ground is becoming cheaper and easier than ever. This new, higher resolution multivariate data provides a significant resource for exploration and resource geologists but comes with the added complexity of effectively integrating the various data sets in useful and meaningful ways to elucidate new geological understanding. Both geophysical data sets and hyperspectral data are extensively used for exploration targeting, providing different information at different resolutions and crustal scales. One of the biggest challenges comes from trying to effectively integrate data sets that record very different physical properties, across the different scales these data are captured at, in a way which can allow for a data-driven analysis of these combined data sets.

Sep 1, 2024

By J Lombardi

OZ Minerals' Prominent Hill copper-gold concentrator is located 130 kilometres south east of the town of Coober Pedy in the Gawler Craton of South Australia. The concentrator was built in 2008 and commenced commercial production in early 2009. The Prominent Hill concentrator is comprised of a conventional grinding and flotation processing plant with a 9.6Mtpa ore throughput capacity. The flotation circuit includes six rougher cells, an IsaMill for regrinding the rougher concentrate and a Jameson cell heading up the three stage conventional cell cleaner circuit. In total there are four level controllers in the rougher train and ten level controllers in the cleaning circuit for eighteen cells.Generic proportional – integral and derivative (PID) control used on the level controllers alone propagated any disturbances downstream in the circuit that were generated from the grinding circuit, hoppers, between cells and interconnected banks of cells, having a negative impact on plant performance. To better control such disturbances, FloatStar level stabiliser was selected for installation on the flotation circuit to account for the interaction between the cells. Multivariable control was also installed on the five concentrate hoppers to maintain consistent feed to the cells and to the IsaMill. An additional area identified for optimisation in the flotation circuit was the mass pull rate from the rougher cells. FloatStar flow optimiser was selected to be installed subsequent to the FloatStar level stabiliser. This allowed for a unified, consistent and optimal approach to running the rougher circuit. This paper describes the improvement in the stabilisation of the circuit achieved by the FloatStar level stabiliser by using the interaction matrix between cell level controllers and the results and benefits of implementing the FloatStar flow optimiser on the rougher train.

Aug 8, 2011

This paper briefly reviews the demise of professional mining education and training in NZ over the past ten years; compares it with the Australian experience; and discusses the immense success experienced by EXITO and the upsurge of competency based education and training we are currently experiencing in the mineral extraction and associated industries. It also looks to the development of a Bachelor in Mining Technology.

Jan 1, 2001

By K L. Silversides

Shales form distinctive peaks in natural gamma downhole logs, which are used to manually identify the location of ore boundaries. These shales form important lithology markers that can potentially be automatically identified using Gaussian processes. This approach is trialled using data from a typical iron ore mine in Western Australia which contains the Marra Mamba sequence of the Hamersley province.The method uses Gaussian processes (GPs) with a single length scale squared exponential covariance function. A library of 8 m sections, where natural gamma measurements were taken at 10 cm intervals down the hole, was used to train the GP model. This library was iteratively improved and was tested using natural gamma logs that were not included in the library. Areas that were misclassified or were not clearly classifi ed were added to the library. The new library was then used to train the model and improve the results. The trials used a double gamma peak from the NS3 and NS4 shales at the boundary between the Newman 1 and Newman 2 ore zonesin the Newman member and the AS1 and AS2 shales at the base of the West Angelas member. The results show that both boundaries can be identifi ed with an accuracy of over 99 per cent. The classification has the highest accuracy on undeformed shales. This method provides a fast, accurate and objective identifi cation of shale and ore boundaries and can potentially replace the current manual detection.

Jul 11, 2011