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Copper, zinc, lead, and silver in the discordant magmatic-hydrothermal orebody of the Conrad Mine, N.S.W., all have a relatively high mean abundance. Any single concordant sulphide orebody containing the same metals has a similar order of mean abundance of only one or two of these, particularly copper, copper and zinc, or zinc and lead.The relative abundances of the metals in the Conrad orebody vary more widely than in concordant orebodies, and the lead-zinc-silver and copper-zinc-lead relationships are significantly different.INTRODUCTIONIn previous investigations of metal abundances in sulphide ores, the basis of selection of the orebodies was their form, and to some extent their geological setting, rather than hypotheses concerning their origin. In all cases they were generally concordant with the bedding of the sedimentary or meta-sedimentary rocks enclosing them, and most occurred in volcanic-sedimentary sequences. Their mineralogies were simple, and they were copper, copper-zinc, zinc or lead-zinc rich in composition. Most were of the type ascribed by several authors to exhalative-sedimentary processes.In one of these investigations (Stanton, 1958), it was pointed out that since the metals in ores of this type showed similar abundance patterns and behaviour, it would clearly be of interest to examine, and to compare with them, orthomagmatic and vein types, unquestionably derived from their igneous rock associates.The present investigation is concerned with a single orebody, of clearly discordant type, and of indisputable hydrothermal origin. The abundance and behaviour of copper, zinc, lead, and silver have been determined and compared to similar data fOl!' the concordant type. Such a comparison tests the possibility that metal abundance patterns of base metal ores may be indicative of the mode of ore deposition.

Jan 1, 1963

Maori economic development still remains an enigma to many people some 157 years after the signing of the Treaty of Waitangi. It has only been in the last decade as a result of increasing pressures from Maori to recognize and settle grievances arising from the Treaty and the resulting compensation issues that "mainstream" has begun to sit up and take notice. While Treaty settlements such as the Tainui, Ngai Tahu and Fisheries settlements have gained prominence as a source of economic potential for Maori, there are significant existing assets owned by Maori worth an estimated $4.6 billion that add an exciting new dimension to Maori contribution to New Zealand's enterprise economy.   Despite the fact that many claims have yet to be resolved, Maori are clearly shifting from grievance to development mode as evidenced by their focus on capacity building through education, strategic alliances nationally and internationally and the significant growth of nett asset worth of Maori interests in a number of industry sectors.   In essence, Maori provide a large un-tapped economic potential in New Zealand. The years of relative economic obscurity appear to have wetted their appetite for positive growth and economic independence. Given current trends, it would not be unrealistic to expect the asset base of Maori to double in value over the next decade and to see the emergence of Maori owned Corporates not only within the New Zealand economy but also trading actively in the global market place.

Jan 1, 1997

THE Broken Hill mining field, approximately 31 miles in length, is at present being exploited by seven companies, viz. : North Broken Hill Limited, Junction North Broken Hill No Liability, Broken Hill Proprietary Block 14 Company, Broken Hill ProprietaryCompany Limited, Sulphide Corporation Limited, Broken Hill South Limited, and Zinc Corporation Limited.The variation in size and shape of the ore-bodies in the mines of these companies, together with the many alterations in pitch and dip, necessitates differences in methods of mining, each company working out its problem in its own particular way.In the matter of chute construction for the handling of the ore broken in the stopes, each mine belonging to the above companies has adopted a style particularly its own, though it may be said that one or two of the types approximate very closely to each other, slight minor differences only being noticed in the design. It is the purpose of this paper to give a brief description of the principal types of chutes now in use in th,e various mines on the field, and in doing so they may roughly be classified into three groups, viz:1. Bulk Chutes, 2. Circular Chutes, 3. Square-set Chutes.The Bulk type of chute is used in the North and British mines of the North Broken Hill Limited, the Central and Junction mines of the Sulphide Corporation, the South Blocks mine of the Zinc Corporation, and the Block 14 mine.The Circular type of chute is used by the Broken Hill South mine and the South Blocks mine.The Square-set chute is used in the Proprietary mine, the Junction North mine, and occasionally in other mines where the square set method of mining is a necessity, and more particularly as mullock passes.

Jan 1, 1925

By M P. Simpson, J L. Mauk

The Golden Cross, low-sulfidation, epithermal deposit shows a number of features that are directly or indirectly related to boiling hydrothermal fluids. Occurrences of lattice calcite and their quartz pseudomorph equivalents in veins, and occurrences of adularia in veins and in the surrounding altered rocks in the vicinity of ore, are both direct evidence of deposition in the presence of boiling hydrothermal fluids. Loss of carbon dioxide causes calcite deposition (platy variety) near the level of first boiling, while adularia deposits due to the attendant pH increase along the cooling flow path. Indirect evidence of boiling include crustiform-colloform quartz banding, late massive calcite veins, clay-carbonate alteration in the shallow and peripheral parts of the ore zone, and the restricted vertical interval of precious metal mineralisation. The colloform quartz banding strongly resembles the banding in amorphous silica deposits found in geothermal surface pipes. This implies that fluids ascending the Empire Vein structure were saturated in amorphous silica. If so, then they must have undergone phase separation, which initiated at considerable depth (e.g. =1000 m) and very hot temperatures (e.g. =300¦C). On the basis of stable isotope data, late massive calcite veins appear to have deposited from CO2-rich steam-heated waters. Calcite deposited along heating paths as these waters descended into the upflow zone during late stage collapse of the hydrothermal plume. In active systems, such steam heated waters form by deep boiling. The high CO2 contents of these waters promote hydrolytic alteration and the formation of clay-carbonate alteration. Reaction path modelling using CHILLER and a deep, Broadlands-Ohaaki water as an analogue, shows that minerals deposit along boiling flow paths over discrete spatial intervals. Calcite and adularia deposit near the site of first boiling, followed by gold and then by amorphous silica. For deep boiling starting at 300¦C, these minerals deposit over a path length that exceeds 1000 m. The distribution of banded quartz and gold at Golden Cross are consistent with such a boiling model. However, the elevation of first boiling must have fluctuated over 500 m to account for the coincidence of lattice quartz (pseudomorphs of platy calcite) and adularia, crustiform-colloform silica and gold over distances of a few centimeters in veins. We deduce that a downward propagating boiling front and expansion of two-phase flashing in a flowing water column occurred during episodes of high vertical permeability and fluid flux in the Empire vein structure.

Jan 1, 2000

By P J. Cullen, B P. Banerjee, S Raval

Continuous monitoring of mining impacts on the surrounding environment is a necessary sustainability criterion. Traditional monitoring approaches such as in situ sampling and airborne and satellite-based remote sensing have several limitations. Over the past few decades, unmanned aerial vehicles (UAVs) have evolved into popular platforms for remote sensing. UAV-based remote sensing has been successfully applied in different sectors, including agriculture, forestry, urban environments and disaster management. However, the potential of UAVs for mine environmental monitoring has not yet been fully established. This paper envisages the use of UAVs and sensor systems to monitor the environment of future mines.CITATION:Banerjee, B P, Raval, S and Cullen, P J, 2015. Unmanned aerial vehicles for mine environment monitoring, in Proceedings Third International Future Mining Conference, pp 137–144 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Brown H. R, Wright E. A

The authors identify the workable coal seams, their distribution in relation to quality and economic occurrence and relate their analytical characteristics to industrial use. The development of established collieries is also discussed with regard to increased production demand.The authors also indicate the potential of the coal resources of the Southern District and postulate their ultimate development.INTRODUCTIONThe Southern Coalfield yields 30 per cent of the total production of bituminous coal in New South Wales. The economic potential of the coalfield was examined last by Harper (1915). Since that time additional knowledge has been gained by prospectors, mining companies and public authorities. Expansion in the steel industry and the building of power stations on the coalfields together with improvements in fuel technology, mining methops and road transport have resulted in production of coal from seams mice thoughtto have no economic value.DESCRIPTION OF THE COALFIELDFor the purpose of this paper the term Southern Coalfield includes also the South-Western Coalfield which together comprise the following Coal Districts:IllawarraDouglas ParkWollondilly-NattaiMoss Vale-Berrima (Hanlon, 1953).Geographically the coalfield is contained by the Illawarra Range in the east, the Shoalhaven River to the south, the Wollondilly River to the west, and in the north by a line...

Jan 1, 1958

By D FitzGerald, S Jakica, R Paterson, J Silic

A new 2.5D airborne electromagnetic (AEM) algorithm has been developed by Intrepid Geophysics and Jovan Silic & Associates. The advantage of 2.5D (2D geology, 3D source) AEM inversion in 3D geological mapping applications and identification of conductive drilling targets, compared to the more commonly used conductivity-depth imaging (CDI) transforms or 1D inversions, are demonstrated using examples from banded iron formations (BIFs) and other geological settings. We show emerging AEM systems are capable of providing estimates of economic rock unit thicknesses, dips and fault definition at an accuracy that mitigates the need for pattern drilling.The 2.5D inversion application used in this work and described in Silic et al (2015) is a substantially changed version of ArjunAir (Wilson, Raiche and Sugeng, 2006), a product of CSIRO/AMIRA project P223F. The changes include a new forward model algorithm and a new inversion solver. The application enables the accurate simulation of 3D source excitation for full domain models inclusive of topography, non-conforming boundaries and very high resistivity contrasts. Solution is accurate for a geoelectrical cross-section, which is relatively constant along a strike length that exceeds the AEM system footprint.The major innovation includes a new inversion solver with adaptive regularisation, which allows the incorporation of a misfit to the reference model and the model smoothness function.Memory usage has been dramatically reduced and is estimated prior to execution. For speed the software has been parallelised using Intel message passing interface (MPI) and can be used on standard computing hardware or computing clusters. Data from survey lines with lengths exceeding 100 km can be inverted on high end laptop computers.We allow flexibility in the selection of components and in the estimation of noise.AEM inversion examples are shown for surveys from BIFs, base metals (volcanogenic massive sulfides) and geological mapping projects and the results are compared with known geology and drilling. We demonstrate the much improved mapping and target definition delivered by this inversion method when compared with the other more common transforms or inversion methods used on these projects.CITATION:Paterson, R, Silic, J, FitzGerald, D and Jakica, S, 2017. High accuracy .D airborne electromagnetic inversion method for banded iron formation and other geological settings, in Proceedings Iron Ore 2017, pp 319–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

A President, soon after he is appointed, sees looming ahead of him the Presidential Address; and in something approaching despair wonders what he can possibly talk about which might hold the interest of his audience. After various casts about, it occurred to me that perhaps prospecting, and more particularly prospecting in Australia, might provide a subject. This is because, 'in the first place, 'prospecting is passing from the stage of chance surface discovery to that of systematic search applying scientific methods to theproblems involved, and in the second, it is the section of the industry with which I have been concerned through much of my: working life. As it makes an address of this sort more interesting if it includes specific reference to actual experience, I hope you will bear with me in such references to actual prospecting as I may use to illustrate the argument. Prospecting has always carried the glamour of sudden wealth. The picture of the prospector engaged, perhaps for years, in fruitless search suddenly coming on riches beyondhis hopes is, deeply etched in the Australian imagination. In few other places has the fervour of prospecting run higher than it did in Victoria in the generation beginning little more than a century ago following the discovery of gold.People arrived from overseas in great numbers. Most of them proceeded to: the goldfields. They moved in thousands from new find to new find. In 'so doing' they determined much of the course of the State's development. The experience of prospectors led them to formulate all sorts of theories little impeded by awkward facts, to account for the apparently unpredictable occurrence of gold.The ideas which men followed, occasionally to success, and which they were prepared to back with all they had were strange and, various, many stories are told of them.

Jan 1, 1959

Willyamite from the type locality, Consols mine, Broken Hill, N.S.W., has been re-examined, and found to consist of zones with widely different Co:Ni ratios. The name willyamite is redefined to include the portion of the (Co, Ni)SbS series with cobalt in excess of nickel. Willyamite is pseudo-cubic, with the three axes equal to within 0·001 A.

Jan 1, 1970

Greymouth River Dredge û Birchfield Minerals Ltd Blackwater Gold Mine û Macraes Mining Company Ltd Globe Progress Gold Mine û Macraes Mining Company Ltd

Jan 1, 1996

The past decade has seen revolutionary advances in communications and information-handling techniques which have been stimulated by "cold war" military requirements and by current programmes for probing into outer space. The tools used in exploration for petroleum and minerals have been improved significantly as a result of this new space age technology and even greater improvements are on the way.Two areas of technical activity have been particularly fruitful in enhancing the effectiveness of exploration methods. These are1. the development of new approaches, based on information theory,for extracting signal from noise more efficiently than before, and2. the use of high-speed digital computers for storing and processing all kinds of exploration information, not only geophysical but geological as well.In seismic prospecting, use of information theory has led to new techniques such as time-domain filtering, wave-number filtering and correlation methods which have made it possible to obtain usable reflection data from areas which were previously considered non reflective. Complex playback and other data processing facilities have been developed to apply these approaches.Digitization of geophysical data for handling by high-speed electronic computers facilitates many of these techniques for signal-to-noise improvement. Direct digital recording of seismic data in the field is now being d'one on an experimental basis in the United States, and this should become a standard procedure, at least for problem areas.The increased dynamic range, flexibility of filtering and other data processing, and convenience of information storage and retrieval make digital recording attractive in spite of its high cost compared to conventional analogue methods. Digital computers are being programmed to carry out many operations in data reduction and interpretation with substantial savings in time and cost over conventional procedures.INTROPUCTIONIn the years that have passed since the end of the Second World War, the western world has witnessed a technological revolution which may be as far reaching in its ultimate impqct as the Industrial Revolution of the last century.

Jan 1, 1963

By Gartrell H. W

During investigations of the treatment methods for ore from the Bird-in-Hand gold mine carried out at Kalgoorlie and at these laboratories, it was found that excess alkali caused a lowering of extraction by cyanide, the cause of this being attrIbuted to the presence of a small amount of oxidised lead compounds in the ore. The subject has been discussed by various writers,3 but no satisfactory explanation of existing facts has been put forward. The experiments described in this report have been carried out with the object of obtaining some insight into the chemical reactions underlying the effect of lead salts and alkalis in cyanidation.The formation of cyanide-insoluble coatings on gold during roasting with lead compounds is well known, but the adverse effect of alkalis in cyanidation of ore is *This paper represents work done under a co-operative agreement between the Commonwealth Council for Scientific and Industrial Research and the South Australian School of Mines and Industries.Published by permission of the Mining Advisory Committee, Commonwealth Council for Scientific and Industrial Research.

Jan 1, 1935

Your Excellency, on behalf of the Council of the Australasian Institute of Mining and Metallurgy, and, indeed, on behalf of everyone present, I extend to you a welcome, and our thanks for your gracious acceptance of the invitation to be here to-day and, later on, to present Honorary Membership Certificates. I also welcome the several official representatives of our Allies, of Great Britain and our sister Dominions.To Messrs. E. C. Driffield and E. J. Rigby, two of the original Foundation Members, who are with us to-day, I extend greetings.The present occasion is opportune to express, on behalf of a representative body of professional men, deep appreciation of the sacrifice which His Majesty the King has made, and will continue to make, by appointing His Royal Highness the Duke of Gloucester as Governor General of Australia and, therefore, His Majesty's senior personal representative in this country.I suppose, that as the primary reason for our assembly to-day is to celebrate the Fiftieth Year of the Institute's existence, I should properly on this occasion, give an account of its history and development. However, as this subject was ably covered by Mr. L. V. Waterhouse, in his Presidential Address in 1938, I trust I may be excused for selecting some other subject. I shall, therefore, exercise my privilege as President and give you a short history of the Mining and Metallurgical Industry of this country with special reference to its effect on the development of the Commonwealth and on the national economy. I apologize in advance for any statistics which I inflict upon you; some of these will be three or four years out of date, because of censorship restrictions. I shall as far as possible refer firstly to the industry prior to and including 1893, the Institute's foundation year, and then to subsequent development.Australia, is pre-eminently a pastoral and agricultural country and it leads the world in the production of wool. Nevertheless, it has an international reputation as a producer of gold and various metals and of minetal products.The development of gold mining in the decade 1840-50 was an epoch-making event in Australia's history, because, to quote one writer's apt phrase, "it precipitated Australia into nationhood." It was certainly responsible for a rapid increase in population. Thus, during the period 1841-1861 the population of Australia increased fourfold, from 221,000 to 1,170,000.The effect of the discovery of gold in Western Australia was even more striking. In 1890 the population of that State was 49,000 and in 1900 it was 180,000.Statistics in respect of gold are reasonably complete, even for the years prior to Federation, and it is interesting to note that the gold declared as...

Jan 1, 1944

Project cost control procedures and computer systems have enjoyed a successful and simple relationship over the past decade, thanks primarily to the proliferation of portable computers or PC's. Prior to the introduction of this technology, project control was largely a manual and somewhat onerous task of historical data compilations, with little time available for dynamic forecasting, staged planning, or pre-emptive cost control. Automated systems developed during this era were resident on "Heavy Iron" or mainframe computers and were expensive to maintain and operate. Use of these early systems was limited to large engineering, construction, and industrial concerns with the economies of scale and funding required for their successful application. Systems were either designed for critical path analysis or task scheduling, but rarely integrated with the other, much less cost control.

Jan 1, 1990

By C Li, D O’Dea, R Moreno-Atanasio, T Honeyands

The behaviour of iron ore granules in the feeding process of sintering is significantly influenced by the material properties of the granulated mix. Therefore, the measurement of key material properties of the iron ore granulated mix is indispensable prior to the simulation of the sintering process based on the discrete element method (DEM). In this paper, three key property parameters of the iron ore granulated mix, apparent density, elastic modulus and rolling friction coefficient, were measured in laboratory-scale experiments. For different sintering processes, the moisture content of the granulated mix normally varies according to the specific requirements for granule size distribution and operating conditions. Therefore, understanding the effect of moisture content on the property parameters of iron ore granules is very helpful in accurately determining the property parameters for DEM simulation work. In this paper, six groups of iron ore granule samples with six levels of moisture contents were prepared through granulation and the trends in apparent density, elastic modulus and rolling friction coefficient with the increase of moisture content were plotted and analysed based on the measurement results. The results show that as moisture increases from 6.9 per cent to 9.1 per cent, the apparent density decreases from about 3000 to 2800 kg/m3. With moisture increasing within the same range, the elastic modulus first decreases from over 200 MPa to below 100 MPa and then reaches a relative constant value of about 40 MPa at higher moisture contents. Rolling friction coefficients are measured using two methods with both indicating a similar trend, with the rolling friction coefficient first decreasing and then rising as moisture increases from 6.9 per cent to 9.1 per cent. The relationship between µr and µ’r is assumed to be similar to that between static and dynamic friction coefficients.CITATION:Li, C, Moreno-Atanasio, R, O’Dea, D and Honeyands, T, 2017. Variation in property parameters of iron ore granulated mix with moisture content, in Proceedings Iron Ore 2017, pp 79–84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By A Brzovic, E Córdova

In an underground mine, different mining activities such as undercutting and cave progression generate redistribution in the present in situ stress field, and these changes are represented in the rock mass through induced seismicity.In order to study and analyse the induced seismicity generated in El Teniente, a block model was developed to account for the dissipated seismic energy through different areas of the mine from 1992 to 2015. More than 2.1 million seismic events were unified and classified in 3D in order to be used for the interpolations. The resultant model variables account for the accumulated energy releases in a monthly time resolution, and provide the ability to intersect different 3D entities with the stored information in the blocks, and estimate the energy evolution inside these entities.The generated model was used to analyse the geotechnical variables that determine the seismic response for the rock mass in the mine, such as geometry and direction of advance of the undercut fronts, lithological domains, and to study the ‘work’ the rock mass needed to go through in order to generate caving in areas with different stress settings.A specific area of the mine under high-stress conditions was analysed by studying the seismic energy associated with two subsidence caves interacting around the project, the modelled lithology. Using the same approach two adjacent projects are analysed to understand the released energy from the rock mass based on different stress and geotechnical settings for each project.CITATION:Córdova, E, Brzovic, A and González, R, 2016. Analysis of progressive seismicity and its correlation with geotechnical variables at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 835–844 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By T Higuchi, L Lu

The quality of iron ore fines have been deteriorating, which has affected sinter quality and productivity adversely. New pretreatment and sintering technologies are therefore required to tackle the gradual change in the quality of iron ore fines. In the sintering process, iron ore fines are first granulated with fluxes such as limestone and coke breeze, and are then loaded and fired in a sinter machine. Sinter productivity and quality are heavily influenced by the reactions occurring in the sintering bed. Hence fundamental understanding of these high temperature properties of ores is urgently needed.Formation of initial sinter melt, penetration and assimilation of nucleus particles by the initial melt, and consolidation and final solidification of final sinter melt are believed to be the key sintering reactions. The assimilation and penetration phenomena have been studied separately in the literature with model particles and diffusion couples and are therefore difficult to relate to sinter quality. In addition, the effect of ore mineralogy has not been studied in detail.In this study, tablets consisting of coarse particles from various iron ore fines as nucleus particles and chemical reagents as adhering fines were made and fired under various sintering conditions to investigate the penetration and assimilation behaviour simultaneously. The degree of assimilation, pore structure, compressive strength of the resultant analogue sinters were evaluated and the relationship between sinter strength and ore characteristics was further discussed. The nucleus particles from Ores A and B were found to be more porous and assimilated more readily with sinter melt, resulting in a viscous melt and a macro-porous sinter structure. The nucleus particles from Ores C and D on the other hand, assimilated less readily with sinter melt, resulting in a fluid melt and a denser sinter structure. This is consistent with the results reported in the literature, suggesting that the present evaluation method can be utilised for studying sintering reactions and predicting sinter quality.CITATION:Higuchi, T and Lu, L, 2017. Evaluation of sintering behaviour based on ore characteristics, in Proceedings Iron Ore 2017, pp 303–308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The mineral industry is an important element in the human environment and in varying degrees contributes to the general standard of living throughout most of the world, both by supplying the basic materials required for heavy industry, transportation, construction, scientific equipment, and many labour saving tools and also by its contribution to the international economy.When projecting population growth and per capita resource utilization against a finite amount of nonrenewable mineral resources, it is apparent that at some future time, if the established trend continues, the supply of industrial minerals will progressively become exhausted according to their relative scarcity and world demand.In one way or another all of nature's mineral resources are used in the sel'vice of man. Some of the products of their manufacture are essential to the survival and further development of our civilization, others are luxuries, desirable but not essential. Marine vessels are essential to maintain a flow of resollrces around the world, and as trade increases the size of the fleet will grow and the quantities of metals needed will be greater.The commodities they transport, may be used in an inefficient or extravagant manner causing unnecessary depletion which may adversely affect the activities of future generations. An example that comes readily to mind is fuel oil, the international transport of which uses a vast tanker fleet. When refined, large quantities of motor spirit are used in motor vehicles. The U.S.A. alone uses 70 billion gallons annually in the 90,000,000 automobiles in use.Much of this is used in private cars-of which there is one for every 2'3 people-for transport between home and city. Well organized community transport would serve the same purpose, conserve a scarce commodity, take some of the stress out of livingdriving in a major city can hardly be considered a relaxing experience-and minimize the problem of atmospheric pollution.Whilst man has demonstrated his great versatility...

Jan 1, 1973

By A L. Zawadski, B G. Putland

"This paper discusses a method to build a calibrated comminution circuit model, using historic operating data and blend information that is useful for forecasting and optimising plant performance, as well as evaluating expansion opportunities. A preferred method for building a calibrated power-based comminution model is discussed and justified based on two case studies, offering low-cost and effective strategies to utilise existing information for the maximum possible benefit.The first example is the Lefa Gold Mine located in Guinea, West Africa operating a semi-autogenous grinding (SAG) and ball milling circuit with recycle crushing (SABC). Daily blend information and operating data was utilised to build and calibrate a power-based model of the comminution circuit. The least squares regression method was used to solve the SAG mill specific energy requirement and the operating work index (Wio) for each individual ore type. The calibrated model was used to evaluate expansion strategies to sustain throughput at higher proportions of fresh ore based on the proposed life-of-mine schedule.The second example is the Ok Tedi Copper-Gold Mine in Papua New Guinea operating a SAG and ball milling circuit (SAB). The circuit limitation would often shift between the SAG mill and the ball mill due to variable ore characteristics and feed blend. Typical SAG mill relief strategies, such as recycle crushing or secondary crushing, required significant capital expenditure and the potential throughput benefit would vary depending on ore type, making economic justification difficult. Daily blend information and operating data was used to build and calibrate a power-based model of the comminution circuit to identify ore types that might benefit from higher blast intensities to increase fines content, thus relieving the SAG mill limitation and increasing overall throughput without a major capital investment.Citation:Zawadski, A L and Putland, B G, 2016. Calibrating Comminution Models Using Operating Data to Forecast and Optimise Plant Performance, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 17–26 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

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