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By F Ouchterlony

Soviet precursors to Cunningham’s Kuz-Ram model from 1983 are described. They are rooted in the mean fragment size and Rosin-Rammler (RR) fits to sieving data and rely on approximations. Three versions of the Kuz-Ram model are presented and all three are de facto based on the median fragment size x50, even if the term mean is used in the papers. This discrepancy caused Spathis in 2004 to suggest a correction procedure for the Kuz-Ram rock factor A, which was said to explain some of the missing fines in the model. This correction, while applicable to Cunningham’s 1983 paper, does not apply to his 1987 paper, in which he presents his own A factor.Common fixes of the Kuz-Ram model’s fines issue are fragmentation models where the fines are mainly generated in a crushed zone around a blasthole. This is contradicted by careful model blasting tests. The lack of a largest block size in the RR function may lead to spurious values of the uniformity coefficient n, eg in conjunction with image-based fragmentation measurements or crusher modelling. These issues may be solved by using the transformed RR function, which has a largest block size xmax or its replacement by the Swebrec function, such as in the KCO model.The mean to median issue is investigated in some detail and it is found that using x50 instead of the mean:has a sounder theoretical backgroundis less prone to errorsis not contradicted by the original Soviet data.It is finally suggested that future work on fragmentation prediction equations focus on the use of distribution independent quantities like percentiles, eg x50, x20 and x80. Some previous work in this direction is briefly analysed and one consequence is that the n-value of the Kuz-Ram model should depend on specific charge.CITATION:Ouchterlony, F, 2015. The median versus the mean fragment size and other issues with the Kuz-Ram model, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 109–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By W Russell, P Wighton, J Franke

Recent advances in ruggedised industrial control system technology and architecture in combination with latest technologies in the fast-evolving 3D LiDAR sensor sector becoming available have enabled the implementation of sophisticated automation algorithms for mining equipment such as bucket wheel reclaimers, as published by the authors in the peer reviewed AusIMM 2019 Iron Ore conference proceedings. This paper provides an overview of a second use case for such automation technology in bulk material ports integral to iron ore operations. The real-time 3D machine-vision based port automation system described in this paper was originally developed for the BHP-Mitsubishi Alliance’s (BMA) Hay Point port. The system has seen deployment at other major mining and general ports in Australia, such as at Dalrymple Bay Terminal (DBT) (shown in Figure 1) managed by Dalrymple Bay Infrastructure Management (DBIM), Hay Point, Queensland. It has the following use cases:

Nov 8, 2021

Consolidated Rutile Limited (CRL) was one of the best performing mining stocks of the turbulent 1980s, having a very high payout of franked dividends. In contrast to some other mining groups, it was not highly involved in the speculative lead-up to the 1987 sharemarket crash. Its base was firmly laid through a succession of decisions that were taken in the period 1982-1985. These decisions and the rationale behind them are outlined in this paper. CRL began the 1980s in a highly favourable position. It had successfully pioneered the transition to high-throughput mining of the high dunes on North Stradbroke Island (NSI), commissioning its 2100 tph cutter suction dredge at the Bayside reserves in 1978 at the time of rising prices, such that it was able to pay off its modest bank loan within 18 months. The June 1980 results showed a record after-tax profit of $5.6M, from total assets fo $26.5M and sales tonnages of rutile and zircon of around 50,000 tonnes each.

Jan 1, 1991

By R MacGillivray

The Golden Cross mine was an open-pit and underground gold and silver operation from December 1991 to April 1998. Closure of the mine has been based on an approach agreed among stakeholders. The initial phase was the release of a closure plan which was regarded as the blueprint for the following phases and the closure works required to implement the plan. The second phase involved lodgment of consent applications and their granting for the final water management configuration. The final phase is monitoring, confirmation that the site is performing as required by the closure plan and consents and settlement of final ownership, management and surety arrangements. Industry best practice modelling techniques have been used to finalise closure design and have been shown to be good predictors of site water management and discharge performance. Site discharges are in compliance with toxicology based water quality criteria for the protection of aquatic life and most discharges from the site, including those from the closed cyanide-tailings facility, can now be discharged without further active intervention or treatment.

Jan 1, 2002

By G Corbett

Epithermal Au-Ag deposits form in the upper 1 km of the crust and are therefore best preserved in the less eroded Pacific rim arcs, although also recognised elsewhere. Two profoundly different ore fluid types give rise to low and high-sulfidation styles apparent as variations in ore and gangue mineralogy as well as characteristic zoned wall rock alteration. Low sulfidation epithermal Au deposits are derived from near neutral composite magmatic-meteoric fluids and divided into a group with a stronger intrusion association within arcs grading in time and space from: quartz-sulfide Au + Cu, to carbonate-base metal Au, and the epithermal quartz Au + Ag, whereas in strongly extensional settings the influx of meteoric waters promotes the development of chalcedony-ginguro banded Au-Ag epithermal veins. In the presence of continental crust particularly in Latin America polymetallic Ag-Au veins represent a Ag-rich equivalent of carbonate-base metal Au and passes upwards to chalcedony-ginguro Au-Ag style. By contrast high-sulfidation epithermal deposits are deposited from an acidic magmatic fluid which provided characteristic hydrothermal alteration by reaction with wall rocks grading outwards as mineral assemblages dominated by: vughy silica, alunite, pyrophyllite-diaspore, dickite-kaolin and then illite-smectite neutral clays. Au mineralisation is commonly refractory with enargite deposited dominantly later within the silica zone.Exploration for epithermal Au deposits benefits from an understanding of the controls to mineralisation which commonly give rise to the development of ore shoots with widest and highest Au grade ore zones. In low-sulfidation systems a combination of competent host rocks, dilatant structures, higher grade styles of mineralisation and efficient mechanism of Au deposition, contribute towards ore shoot formation. High-sulfidation epithermal Au systems occur in permeable volcanic and breccia host rocks which are linked by major structures to the magmatic source.CITATION:Corbett, G, 2013. Pacific Rim epithermal Au-Ag, in Proceedings World Gold 2013 , pp 5-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

Information obtained from a reconciliation system provides fundamental indicators to an operations performance and is often neglected as a key performance indicator when developing a business plan or mining schedule. The cycle of exploration, ore definition, mining and processing within a company is constantly scrutinised both internally and externally as to the safety, environmental and financial performance of these activities with the operators judged on their performance on a periodic basis. However, it is not unusual for the reconciliation process to be given scant attention until a serious issue (usually a shortfall) occurs, at which point short-term solutions may be implemented which only serve to compound the original problem. A robust reconciliation system takes time to develop and implement initially and must continue to evolve with time. The best systems are those where all the stakeholders in the ultimate outcome are involved in the design and accept responsibility for the validity of their component inputs. Output from the reconciliation process can be utilised to fine-tune all aspects of an operation once the underlying issues leading to a particular result are understood.

Jan 1, 2002

I wish that in addition to being a Pro- fessional Engineer I was also a communications expert. My principal task this morning, and yours after this meeting, is to convince a wide variety of individuals that steel industry slags are a high quality material that can be used for many purposes; and that their use can significantly alleviate some of the problems facing engineers, public officials, and the general public in our countries. By actual in- place performance over a long period of time steel industry blast furnace slags have proven that they are as good as the best natural aggregates, and better than some, for any type of construction or purpose for which natural aggregates are used. Steel furnace slags have many unique favorable characteristics and prop- erties when compared to other types of aggre- gate even though they cannot be used for all types of construction. We have the facts, all we have to do is present them to the right people in the proper manner.

Jan 1, 1979

By Stubbs B

In conjunction with Charles Copeman, we have arranged the presentation of a paper by Charles with a support paper by myself presenting alternatives to currentaccepted legal concepts involving the ownership of minerals by the Crown and the absence of ownership in any minerals or entitlement to benefit therefrom by the owner of the land on or under which the minerals occur.2. The current situation has its historical route in the concept of gold and silver being royal metals and belonging wherever situated in the Kingdom to the King and it is submitted it can be'seen as being archaic in nature perhaps even feudal and perhaps worthy in this day and age of reconsideration.Our purpose in these papers is to present an alternative view supported by argument challenging the present system and hopefully, creating room for comment and interchange amongst those involved in the industry. My solutions are not Charles Copeman's solutions and vice-versa. However, we do share a common belief that the present system may not be the best system.

Jan 1, 1990

One distinctive feature of the global mining industry approaching the twenty-first century is the worldwide commitment of mining houses to large-scale projects in developing countries. One good example is BHP's development of the Escondida copper project in Chile. The Escondida orebody was discovered in 1981 and construction began in July 1988. Mining began in December 1990 at a design capacity of 320 000 tonnes of copper contained in concentrate. Out put has grown significantly and shortly Escondida will become the largest single copper mine in the world producing copper at the rate of 800 000 tonnes per annum, including 80 000 tonnes of copper metal. Escondida provides a case study of the development and growth of a large-scale mining operation in a developing country. Key elements have been innovative financing, the management of country risk, the recruitment of an excellent workforce, the use of advanced technologies and best practice in environmental management and community relations. Escondida is one of the global mining industry's success stories in the 1990s.

Jan 1, 1996

A good blending system is one that ensures that a plant can cope with the amount of grade variation that it will encounter. Prediction of amounts of variation that will be encountered on time or tonnage scales that are important should be regarded as an essential part of the planning of mines and plants. In some cases, the natural amount of grade variation when ore is mined and handled in the cheapest way will be acceptable. In other cases, it is necessary to understand the effects that various ore-handling processes have on amounts of grade variation at various scales and to design a blending system with considerable care. Blending tends to matter more when plants are sensitive to many aspects of grade. It can be very difficult to find the best compromise between capital cost and the amount of grade variation. In these cases it is important that ore blending options be considered carefully as part of the planning of mines and plants. Failure to make plans that consider likely amounts of variation can be very expensive.

Mar 1, 2010

By Bailey H. W

Power supply for remote mining developments is compared with supply to the general public with the conclusion that the private power plant operator has many opportunities to minimise his costs which are not open to public utilities. The main features of diesel, gas turbine and steam power plant and the limitation upon their application which may be imposed by the fuels available and the local conditions at remote sites are outlined. Reference is made to the value of joint examination by the mining engineer, metallurgist and power engineer to decide how to make best overall use of capital, labour and energy in co-ordinating the design of power and process plant and in setting no more than adequate standards of reliability and efficiency. Fluctuations in world markets make it difficult to plan mining operations to a firm time base. Suggestions are made to minimise the financial risk in forward expenditure upon power plant which in large sizes due to longer construction time may have to be ordered before a final decision is taken upon the mining development it is to serve.

Jan 1, 1973

The drilling and evaluation of bore cores provides the best available statistical basis for characterizing a coal prospect. Important, long-term decisions by management frequently must be based on the results. The majority of coal mined presently is used for steam raising or the production of metallurgical coke. Common bore core tests and analyses appropriate to this usage can be cate- gorized as non-destructive, chemical, physical, petrographic, caking/plastometric and propert- ies of non-coal material. The major tests within each category are described. Certain specific information from the bore cores is required by the coal geologist, mining engineer, coal preparation engineer and the user, either individually or as a group. The optimal bore core evaluation test pro- gramme is the one which satisfies the needs of all the professional disciplines with the grtatest speed and at minimal cost. The principal steps in such a programme are listed. There is an urgent need for a bold new Australian standard to provide the necessary guidelines to an industry which at present lacks uniformity in its approach to the task.

Jan 1, 1977

Territory Iron has seen fit to revive the old Frances Creek iron ore mine some 30 years after it ceased operations in AustraliaÆs Northern Territory. The key to this revival has been the changes that have happened since market forces, infrastructure limitations and a cyclone combined to force its closure. As it breathes life into this old mine, the Company is serious about its responsibilities to its shareholders, to its workers, to local and regional communities and to the environment. This paper addresses how Territory Iron has approached technical, operational and regulatory issues that apply in Australia. Some insight may be gained into the myriad of tasks that mining companies face to revitalise an old mine. These tasks vary from employing the latest exploration tools, best practice drilling, sampling and modelling of orebodies, optimisation of pit designs and schedules, maximising product value by blending, optimising infrastructure usage and minimising capital and operating costs. All of this has to take cognisance of commercial, environmental and other issues including Native Title.

Jan 1, 2007

Data collected from payload management systems at a number of surface mining operations show significant variance. Heavily loaded trucks travel slower up ramps than lightly loaded trucks. Faster trucks are slowed by the presence of slower trucks, resulting in 'bunching' and production losses. A stochastic model was constructed to simulate a truck haulage return cycle of 12.5 km at a large open pit gold mine in the USA. For a fleet of 35 trucks, the best estimate of the benefit achieved by a sustained reduction in payload variance of 25 per cent is a throughput increase of 1.6 per cent, within a possible error range of 0.6 to 3.2 per cent. This potential benefit is worthy of further investigation by Continuous Improvement teams at large open pit mines. The model also indicates that, under the right circumstances, provision of an overtaking lane can provide throughput benefits of up to ten per cent, The feasibility of providing unidirectional haulage circuits within large open pit mines should be examined.

May 1, 2010

Geologists often classify ore textures on the basis of the origin of the rock in which they form and the grade of one or more minerals within the ore (Sinclair and Blackwell, 2002, pp 32-36).  Metallurgists, on the other hand, need to know how best to process the ore in order to extract the valuable minerals from it (Petruk, 2000). Geological classification has the following disadvantages:it requires the services of skilled economic geologists, of whom the supply has been dwindling for many years;it is subjective, depending on the perceptions of the individual geologists who make the classification; andit may relate only weakly to processing requirements of the ore. We describe methodology for automatic classification of ore textures from images of drill core. The images analysed are æclassifiedÆ images, in which a particular mineral (or mineral group) is assigned to each pixel. The new methodology is intended to:provide a quantitative and reproducible alternative to traditional geological texture classification,relate to process mineralogy of the ore, andimprove the ore-texture-related input to orebody domaining and geostatistical block models.

Jan 1, 2008

Various factors influence the exploration geologist or geochemist in his choice of.an analytical method for gold and other elements which may help him find the elusive gold deposit. One of the first decisions the geologist must make is the nature of sample media to collect for his survey. Needless to say there are many media available depending on the situation. These include rocks, soils, heavy mineral concentrates (from overburden drilling and panned concentrates), humus, vegetation, water, lake bottom sediments, stream sediments, etc. The choice of the sample media will depend to a large degree on the state of development of the particular project from grassroots to mine feasibility. The nature of the geological information required will affect which media and which analytical technique should be chosen for the analysis. Valid sampling from the initial sample collection, preparation and subsampling aspects may also help to determine which analytical procedure is best. Cost and turnaround time are of prime. importance to the explorationist, as it should be, however, these aspects should not be detached from receiving accurate and reliable results.

Jan 1, 1987

Australia has been an important producer of zinc minerals and metal for many years.Late in the last century Edgar A. Ashcroft, a versatile and enterprising electrical engineer proposed the treatment of zinc rich ores by roasting, followed by leaching to extract zinc, purification of the solution and electrolysis of the purified solution to produce zinc. Residues from the leaching operation were to be smelted in a lead blast furnace to recover lead, silver and gold.Ashcroft (1897-98) and (1898) has.given us a most interesting record of the attempts made at the Sulphide Corporation's plant at Cockle Creek near Newcastle, NSW, to put his ideas into practice. In spite of the best efforts of all concerned, including the use of electrolysis of aqueous chlorides and sulphates, zinc could not be deposited consistently and the project failed although lead smelting continued until 1922 (Woodward, 1965, p. 158). Based on later experience with Broken Hill materials the presence of undetected cobalt in the solutions was the likely cause of the inability to deposit zinc (Kirk and Othmer, 1956).

Jan 1, 1985

By Davison GR

The cost of drilling consumables is always a large component of any mine budget. It is important that this cost be carefully examined with a view to reducing the overall cost per inetre or at least minimising its escalation.At Renison it is considered that the only way to ensure drilling costs do not rise unduly is through a total system of control from purchase to disposal.In 1979 extension of an existing drill supply service contract was carefully examined and abandoned in favour of a hybrid system. This system is providing a great deal of control over the use of drilling consumables and has maintained a relatively constant cost per drilled metre over the last five years.Current consignment stock contracts for drilling consumables are strictly specified by the Technical Services section of the Mine Department and consumables purchased under these contracts are distributed and refurbished/sharpened by a contractor.The total result of this package is individual drilling items that achieve the best cost per metre and careful distribution and maintenance to ensure maximum life.

Jan 1, 1985

Reconciliation of the ore reserve has been an integral part of mine planning since Bougainville Copper Ltd. commenced mining operations at Panguna in 1972. Confidence in the ore reserve is considered essential, both for long term planning of the deposit, and for fair and accurate reporting of the mining resource to shareholders. Recoverable, proven reserves are published annually. Although the ore reserve quoted is based only on diamond drill hole (DDH) information on a 122 metre by 122 metre grid, predictions are regularly reviewed against production. Concentrator results are taken to be the best estimate of grade and tonnage. Surveyed mined perimeters and average blasthole grades are reconciled at the end of each month against the concentrator figures. Predictions of the in-pit reserve are made using an orebody model. DDH and blasthole (BH) sample grades are used to make predictions for both long and short term planning. This paper describes how reconciliations are used to validate ore reserves at Panguna. Development of the orebody model is described, and some of the difficulties encountered in doing reconciliations are addressed.

Jan 1, 1987

A Feasibility Study to determine the future of ZC Mines was completed in mid 1987. Early in this study, which lasted two years, it was identified that significant reductions in treatment costs would result if the Zinc Corporation Concentrator was closed. All of the production from the existing two mines, The Zinc Corporation Limited (ZC) and New Broken Hill Consolidated Limited (NBHC), would then be treated in the concentrator at NBHC.After a partial upgrade of the NBHC concentrator, the ZC concentrator was finally closed and all of the equipment disposed of. This closure highlighted the need to concentrate all ore haulage in one shaft to further reduce operating costs and remove the cost of surface transport of ZC production to the improved NBHC concentrator. This paper outlines the changes that were made to improve the haulage system for ZC Mines. After a number of options were investigated, it was finally decided that the upgrade of the existing NBHC haulage shaft was the best option even though some production would be lost while the upgrade was in progress.

Jan 1, 1988