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The maximum current density at which conventional copper electrowinning plants will result in satisfactory, adherent, and dendrite·free cathodes is determined by the thickness of the diffusion boundary layer. A decrease in the value of that thickness will permit an increase in the current density. This fact is utilized to develop a high current density cell in which the reduction of the boundary layer thickness is accomplished by means of a specially designed electrolyte circulation system. The high current density cell is used to determine the effect of current density on such process parameters as current efficiency, cell voltage, power consumption, and cathode purity. A number of empirical equations are developed for the purpose of estimating the magnitude of these effects.

Jan 1, 1972

THE Phillips River gold and 'copper field is situated on the south coast of Western Australia, about 200 miles east of Albany, 180 miles west of Esperance, and: 250 miles south of Southern Cross, forming the southern extremity of what Mr. H. P. Woodward classes as the fourth belt of Pre-Cambrian rocks, and the first auriferous belt, whicf extends northward through Southern Cross, Mount Magnet, and Cue. The field may be considered the premier copper producer of the State. The first mineral discoveries were made about 1892; when gold, copper, and iron pyrites were found; but, owing to the isolation of the district and the scarcity of water, both in the locality and on the route thereto, little work was done for some years. In1899, however, payable gold reefs were opened up, and the district began to attract attention.The southern portion of the district is composed of limestone and sandstone rocks, forming the coastal series, and is for the most part flat, broken only by a few low hills and ridges, except to the west, where Cape Barren and Eyre's Range stand out...

Jan 1, 1917

By H Park, D J. Holland, L Wang, Y Matviychuk, Y Lee

Reuse of process water in mineral and coal flotation plants is widespread to effectively reduce freshwater consumption. However, the accumulation of the frother in the recycled process water is a growing problem as high remnant frother concentration often leads to undesirable overfrothing issues throughout the plants. Various approaches have been proposed by others to measure frother concentration, but none of them is used in flotation practice owing to the requirement of timeconsuming sample preparation steps and/or specialist training to operate and maintain. There is a pressing need for the development of a simple and fast frother concentration measuring technique to avoid overfrothing issues and to optimise the flotation process. The present paper presents two promising approaches to measuring frother concentration online. The first approach measures the concentration of alcohol type frothers based on the host-guest interactions between frother molecules and a formulated liquid. This method is simple and fast as it only requires mixing the formulated liquid with the water sample for up to one minute. The potential of this approach was demonstrated by determination of the residual MIBC concentrations at different locations across a coal flotation plant. The second approach measures frother concentration using a solid-phase extraction (SPE) process and a cryogen-free benchtop NMR spectrometer. Using this approach, both alcohol type and polyglycol type frother solutions can be analysed for concentration determination within 30 minutes. It has also been demonstrated that the concentration of individual frothers in a frother blend (ie MIBC and PPG425 in water) can be accurately analysed even in the presence of background chemicals. This technique has otential for real-time measurement of frother concentration as the whole process can be fully automated.

Aug 24, 2022

The published liquidus data on the Pb-PbS system have been correlated on the basis of one-coefficient Margules equations. Thermodynamic properties of the components of this system have been obtained, and it has also been found that the calculated miscibility gap of this system exists over a very narrow range of temperature (1041 to 1058°C).

Jan 1, 1972

By D Roldpo, M Vidigal, J F. C L Costa

The local cumulative distribution function (lcdf) of a selective mine unit (SMU) can be estimated by conditional simulations using the statistics derived from the sample points, generating multiple equally probable scenarios. Conditional simulations permit the evaluation of the lcdf at any support, taking into account the spatial variability, ie the variogram, and the two statistical moments, mean and variance, of the conditioning samples. The SMU ore losses and dilution depend on the mining method and mining equipment selectiveness that, in its turn, depends on the predicted block size. A new approach to predict ore loss and dilution was developed in this study. Monte Carlo simulation is used to randomly generate a grade value derived from the lcdf at the mining stage (Zs_mc(t)) in order to make a decision about the SMU destination, ie processing plant (ORE) or waste dump (WASTE). If Zs_mc(t) is lower or equal to the cut-off (Z_cut-off) the block is ORE and, conversely, if Zs_mc(t) is higher than the cut-off (Z_cut-off) the block is WASTE. Considering these binary destinations ORE/WASTE, at the mining time t, and combining each realisation of the simulated random function Zcs_i (X), there are four possibilities for each SMU simulated value: 1. the block was simulated as ore and is actually ore (OO), 2. the block was simulated as ore and is actually waste (OW),3. the block was simulated as waste and is actually ore (WO), and 4. the block was simulated as waste and is actually waste (WW).The dilution factor is given by possibility 3 (WO), while the ore loss factor is represented by possibility 2 (OW). These results comprise the classical classification and reconciliation plots used in the mining industry. The new procedure proposed in this paper is based on the use of all the equally probable simulations to define the ore loss and dilution factors. An application of this methodology was carried out at Vale's iron mine in Brazil. The grade of silica was simulated and 50 multiple equally probable 3D models were generated. The mean and the standard deviation of the ore tonnage (OO + WO) for the 50 realisations, was 233 Mt and 0.5 Mt, respectively. The mean grade increased for the diluted ore (OO + WO) as well as their respective coefficient of variation (CV). The CV increases from 62 per cent in the undiluted ore (OO), to 101 per cent in the ore, considering the dilution factor (OO + WO). The mean ore loss (OW) was 10 Mt and the waste tonnage dilution (WO) was 9 Mt.

Jan 1, 2009

By K White, R Hardie, J Merritt, B Kirsch, R Lucas

Constructed stream diversions are a common element of mine sites across Australia. A review of constructed stream diversion performance in the Bowen Basin funded by the Australian Coal Association Research Program (ACARP) in 1999 found over 80 per cent of constructed stream diversions failed to meet regulator and operator expectations. Since that time, improvements have been made in the assessment, design, monitoring and management of constructed stream diversions. Fundamental to these improvements has been the development of a better understanding of the regional stream systems and efforts to replicate the natural stream processes in the function and operation of constructed stream diversions.This paper discusses the history of constructed stream diversions through the Bowen Basin in central Queensland recorded in the outcomes of a series of ACARP funded research projects. Further, the paper reports on the outcomes of a current ACARP funded project that has reviewed the success or otherwise of constructed stream diversions in the region. The assessment has compared the performance of diversions that have been designed to replicate and provide for ongoing stream geomorphic processes with those diversions that were designed and built prior to the development of these design improvements. Based on these investigations we have identified design and construction successes and issues requiring further research and management attention.CITATION:White, K, Lucas, R, Hardie, R, Merritt, J and Kirsch, B, 2013. Challenges and opportunities for constructed stream diversions in the Bowen Basin, Central Queensland, in Proceedings Water in Mining 2013 , pp 73-82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

THE nature of the ore deposit of the Broken Hill line of lode is such that it can be broadly divided into two the calcitic and siliceous ore bodies. The principal minerals occurring in these ores are: Galena, sphalerite, pyrite, arsenopyrite, chalcopyrite, pyrrhotite, calcite, rhodonite, garnets, feldspar, fluospar, quartz.Whilst these minerals persist in both classes of ore, the following typical analyses of Broken Hill South Limited ore bodies will give some indication of the disposition with regard to each:

Jan 1, 1928

By T Harrington, M Cox

There have been many changes in the Australian mining industry during the last 30 years. One of the most dramatic changes, from a geological perspective, is the reduction of in-house geological staffing and an ever increasing reliance on contract and consulting services. As a result, there has been a change in the way geological information is generated, managed and retained within the industry. This paper describes the changes that have taken place in the industry, provides two case studies of how companies manage their geological Intellectual Property and reviews some of the issues associated with management of in-house and outsourced geology services.

Jan 1, 2009

By Giannini L. M

The determination of the "optimum pit limit" of a mine has long been considered as a fundamental problem of mine planning. A number of mathematical techniques have been proposed to solve this problem some of the more elaborate ones posing considerable computational difficulties for their implementation. Barnes and Johnson recently introduced "bounding techniques" to ease the computational effort required for determining the optimum pit. The aim of this paper is to point out and correct some errors in their techniques. A presentation of a general bounding algorithm is given.

Jan 1, 1985

By McLean E. J

Background The resources of the Gippsland Basin include not only the coal and oil for which it is well known, but also the tourism resource and the quality of life which it offers its residents and visitors. To manage this group of resources requires an understanding and ability to predict the consequences of possible developments. The water of the streams and estuaries as a key component as it is both a resource and the means for transporting wastes from one area to another. To aid in the resource planning process there is a need for models of the estuarine hydraulic processes. This paper describes an appropriate modelling technique. Resource use conflicts may arise from developments in the catchment upstream of the estuarine reach. For example the diversion of water for domestic and industrial use will change the velocity and salinity structure of the downstream estuary. In turn these changes will affect sediment distribution and deposition patterns and may impose stress on the biological communities and ultimately on the fisheries resources and water quality. The manager of an estuarine system may have expertise in ecology, hydraulics or another of the specialist disciplines involved, but commonly will not. The manager will identify needs for resource and development and the broad options required to satisfy them. The manager will use these studies as the basis for his/her selection of the option for execution. Thus a model for'use by the manager of an estuarine system must have the following properties: (i) The model must be sufficiently accurate to throw up all the likely options. (ii) The model must be capable of being run by the manager, interactively, to answer `what if' questions. This requirement implies a simple code andhardware limited to a personal computer or possibly a desk top work station. (iii) The model must be robust so that unrealistic input oes not generate apparently useful output, and no output is generated for cases where the model is not designed to give results. (iv) The model must be capable of being used as part of a modelling system comprising models of all the geographic and demographic components

Jan 1, 1992

The history of the industry which recovers rutile and zircon from the heavy mineral beach sand deposits of Eastern Australia began with the initial discovery of zircon in 1895. Whereas a large number of small companies operated during the rutile boom of 1955-57, the industry is now controlled by a few large groups.Mining is mainly by suction dredging. Metallurgical practice is a two-stage process in which a bulk concentrate of heavy minerals, recovered by gravity methods, is separated into its constituent minerals by processes based mainly on surface, electrical, and magnetic properties.Various separating devices using these principles have been developed in the industry and combined in various ways in the operating plants.There is scope for future metallurgical developments.INTRODUCTIONThe existence of deposits of heavy minerals ("black sands") on the northern coast of New South Wales has been known for at least 90 years. The earliest metallurgical operations aimed at the recovery of gold, platinum, tin and monazite. Mainly because of the low grade of these deposits with respect to these minerals, but also due to metallurgical difficulties, such operations were abandoned by about 1895 (Whitworth, 1959). The presence of zircon was recorded quite early (Carne, 1895) but Raggatt (1925) appears to have been the first to report the presence of rutile.The economic exploitation of the deposits was initiated in 1928 when D. H. Newland, State Geologist of New York, made an examination on behalf of The Titanium Alloy Manufacturing Company of America. Developments were then delayed by the world-wide depression, and the first commercial separation of the heavy minerals was made at Byron Bay in 1934 by Zircon Rutile Ltd. using a froth...

Jan 1, 1963

By R Goddard

An alternative stoping method has been adopted for narrow vein stoping at the Tasmania Mine in Northern Tasmania. Colloquially described as ‘Radial-in-Reef’ (RiR) stoping, the method employs the drilling of radial rings in the plane of the Reef from a drill stub located at the geographic centre of the proposed stope panel.Production from the Western Zone of the Tasmania Reef has been undertaken remotely from the Reef since 2007, after a detailed geotechnical engineering analysis indicated that the integrity of the sill drives could not guarantee an acceptable level of confidence should an anticipated seismic event occur within a radius of 10 m. The key tenet of the remote mining approach was the exclusion of personnel from sill drives once stoping had commenced. The remote mining method had to be ‘retrofitted’ to four existing stoping blocks totalling 11 sill drives which totalled 160 m vertically. The remote mining method proved to be complex, cumbersome and very expensive. However, the ore was extracted successfully.By early 2010, previously developed ore had largely been exhausted and the future development with an orebody open at depth presented the opportunity to review the current extraction method. However, the new extraction method needed to maintain the tenet of excluding personnel from sill drives of active stoping blocks, but seek opportunities to reduce the difficult and costly aspects of the previous method. The new ‘Radial-in-Reef’ stoping reduced the development requirement from six to two drives per ore block. Cost implications aside, the significant reduction in prestoping extraction ratio was expected to also reduce the likelihood of seismicity. Transverse production rings were designed to be drilled radially from a drill stub mined from a mid-stope footwall drive. Stopes totalling up to 7000 tonnes were planned be fired in a single electronic blast. Extraction was designed to take place from a basal sill drive under teleremote operation. At the time of writing, the method was under trial.

Mar 21, 2011

By C J. Greet, S Jacques

In most instances, the application of high-chrome grinding media results in an increase in the recovery of the valuable mineral(s). The authors have published data from a number of plant-based case studies, which indicate that it is not unreasonable to expect a recovery increase in the vicinity of 1.5 to 2.0 per cent for a copper ore. It is of interest to understand where the increase in recovery is coming from. That is, is the additional copper recovery the result of improved fine particle flotation or is it due to an improvement across all size fractions?This paper aims to answer this question. Laboratory flotation tests were completed using forged steel and a high-chrome alloy on a volcanogenic massive sulfide copper ore. The unsized data indicated that the application of high-chrome grinding media to this ore resulted in an improvement in both copper recovery and copper concentrate grade. A detailed kinetic analysis of both the copper sulfide and gangue minerals was completed that clearly shows that the change to a more inert grinding media produced significant increases in the flotation rate constants (both fast and slow) across all size fractions. It is also possible to observe that the change in pulp chemistry has resulted in a decrease in the flotation kinetics of the -20 micron pyrite, while the coarse pyrite recoveries have increased, presumably because of an increase in the flotation of the chalcopyrite/pyrite composite particles.CITATION:Greet, C J, Jacques, S and Kinal, J, 2014. Recovery-by-size kinetic analysis to determine where metallurgical improvements occur when converting to high-chrome grinding media, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 217–224 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Miskelly N

In Australia and New Zealand, the 'Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves', which was released by industry in 1989, is operating successfully in a co-operative approach between industry and regulatory authorities. Similar codes or guidelines exist or are under development in the United States of America, Canada, the United Kingdom and South Africa, although the regulatory backing given to the Australasian Code is unique. International standard definitions for Mineral Resources and Reserves, and for categories of Resources and Reserves, have been under development by the Council of Mining and Metallurgical Institutions since 1994 and have already stimulated considerable convergence of definitions and reporting standards in participating countries. It is hoped that agreement on this international standard for public reporting by mining companies will be reached within the next two years, and it is expected that adoption of the standard will result in a higher and more uniform quality of reporting worldwide, with a consequently greater interest on the part of the general public and financiers in investing in the mining industry.

Jan 1, 1997

Taking the Presidential chair of the Australasian Institute of Mining Engineers, my first duty is to thank you for the high honour and position you have conferred on me. A position entailing the highest compliment the Institute could bestow on any of its members, and one which I feel my inability to properly fulfil, inasmuch, as you have men in your ranks of the highest scientific training residing on that great continent where the head quarters of the Institute is established, while my engagements here will not permit me leaving this colony but for a very limited period.About six years ago, during the time the mining boom was at its height, there came to this colony from England, Germany, and South Africa, several mining engineers, who in conjunction with the mining engineers here, formed an Institute which we soon found we were not able to maintain. The mining boom gradually died away, and many engineers have left the colony to find employment in other parts of the world. We made overtures to your Iqstitute to take us under your wing, which you were kind enough to do, and the outcome is that you have come over 1200 miles to hold a meeting in New Zealand. The paucity of members residing in this colony does not admit of a large attendance; but we heartily welcome you to our shores and hope you will enjoy a holiday visiting some of the principal mining centres and exchanging ideas, which not only improves our minds, and widens our field research, but also tends to lead to further economic improvements in the extraction of metals the earth contains...

Jan 1, 1903

By W M. Tekano, T S. Coulter, N M. Hutt

The Vancouver Island Highway Project (VIHP) was a $CAD 1.2 billion expenditure by the Province of British Columbia to improve travel safety and relieve traffic congestion between Victoria and Campbell River on Vancouver Island. In the section of highway between the Tsolum River and Oyster River, on the Inland Island Highway portion of the VIHP, over half of the rock to be cut and filled was found to be net acid generating. The Tsolum River has been impacted by metal leaching and acid rock drainage (ML/ARD) for decades from an upstream closed minesite. Geochemical testwork indicated: over half of the rock along this section of highway was potentially net acid generating based on a site-specific SNPR (=NP/SAP) criterion of 1.5; some core samples were already acidic; pyrite occurred in disseminated framboidal and gel forms; the rate of acid generation was not high; measured neutralisation potential (NP) provided some lag time for the onset of net acidity; and non-carbonate neutralising minerals prevented low pH (These predictions led to ML/ARD controls involving: realignment of the highway; elevation control to minimise the volume of disturbed rock; encapsulation of blasted-rock fills within the highway, surrounded by low-permeability till and covered with asphalt; and diversion of water away from cut faces. Internal pipes drained any water reaching the fills into external ditches and ponds, where the water could be monitored and, if necessary, treated. Water from the cuts was also captured in ditches and carried to monitored ponds. Elevated aqueous sulfate concentrations in several ponds confirmed that sulfide minerals were oxidising, but the lack of both acidic pH and increasing trends in concentrations demonstrated that ML/ARD was controlled. Contingency plans for any pond that may become acidic include water treatment, which predictive testwork has shown would not require substantial amounts of limestone or lime.

Jan 1, 2003

By Bucknell WR, Clarke DE

The paper provides a company's view of the relative merits of various valuation methods and outlines the basic approach it takes to the valuation of an exploration property. The negotiating process and methods of acquiring an interest in an exploration property is discussed The valuation methods discussed are: 1. Exploration Expenditure. 2. Real Estate. 3. Joint Venture Terms. 4. Rule of Thumb. 5. Net Present Value - Discounted Cash Flow. 6. Geoengineering.

Jan 1, 1994

By Miller J. D

The mechanism of adsorption of gold from alkaline cyanide solutions by carbon has been the subject of much research over the past decade. In this paper, the nature of the gold cyanide adsorption phenomenon is investigated, particularly with respect to carbon substrates and associated surface adsorp- tion sites.

Jan 1, 1991

By Mech B

This paper gives a general description of mining practice at The Zinc Corporation Ltd., Broken Hill, New South Wales.The basic mining methods are those which have been common in Broken Hill for many years and have been well described in previous Proceedings. The main object of this paper is to indicate developments which have occurred in recent years and to describe changes in layout, mining methods and equipment which are taking place at present.The following headings have been adopted: History Geology and general characteristics of the orebodies, Geology, The lead lode, The zinc lode, General characteristics, Ore reserves, General mining method, Exploration and diamond drilling, Shafts and shaft sinking, Main shaft, Old main shaft, Block 5 shaft, New upcast airway, Development, Level interval, Level layout, Driving and crosscutting, Winzing, Rising, and Stope preparation.

Jan 1, 1946

By P Moser, P Schimek, F Ouchterlony

This paper summarises the findings of 27 model-scale bench blasts in magnetic mortar, which were conducted from 2011 to 2014 at the blasting site of the Montanuniversitaet Leoben.The aim of the study was the investigation of the influence of blasthole delay times in small-scale bench blasts on the face characteristics and cracking damage created in the surrounding rock, which affects the fragmentation in subsequent rows.The test specimens or blocks, which were produced out of magnetite concrete, were roughly 1:100 in scale to normal bench blasts. The confinement of the testing blocks at the sides and back ensured the similarity to normal bench blasts with regard to the wave transmission into the surrounding rock. The specimen contained three or four rows with five blastholes each and were shot row by row, with virgin (undamaged) material in row 1 and increasingly damaged or preconditioned material in the following rows.The tested delay times varied between 0, 28, 73 and 140 µs, which corresponds to 0, 0.4, 1.0 and 2.0 ms/m of burden.The evaluation of the material properties showed that the use of magnetite concrete eliminated the inhomogeneous behaviour of rock, but some unexpected differences of the individual production cycles were still detected.The characteristics of the bench after each blast was evaluated along three horizontal lines out of a 3D model of the bench face. The tested delay time sequences of the virgin (first row) and single preconditioned blasts (second row) produced more overbreak for longer delays, while the third-row shots resulted in a smoothened surface independent of the chosen delay.The introduced damage after every blast was evaluated by an observation of irregularities on the newly blasted bench face. The visible cracks at the top of the testing blocks were documented and divided into several crack families according to their angle, length and origin. The remaining block was broken out of the blasting site after blasting, cut into several horizontal and vertical slices and dye penetrant spray was used to visualise the cracks created. Some of the detected crack families showed an influence of the delay time. The calculated mean crack density and mean crack intersection density showed that longer delays resulted in a higher degree of damage.The fragmentation results were well reproduced by the basic three-parameter Swebrec function. The observed improvement of fragmentation in the second- and third-row blasts was linked to the preconditioning of the burden for the following row while blasting the actual row. With the exception of the simultaneously initiated blastholes, the blasts showed coarser fragmentation for the shortest delays, while the longest delays generated the finest fragmentation.CITATION:Schimek, P, Ouchterlony, F and Moser, P, 2015. Influence of blasthole delay times on fragmentation as well as characteristics of and blast damage behind a remaining bench face through model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 257–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015