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The Australasian Institute of Mining and Metallurgy brings together, voluntarily, people with a professional interest in the disciplines and skills which are employed in the mineral indus- try, and in relation to that industry. We come together because we have a mutual interest in improv- ing what is done by the mineral industry, in all its aspects. It is this sense of continuing improvement, of doing better, of doing as well as we can, as our knowledge and skills improve, that unites us in creating and fostering a professional association of like- minded people. We know from our professional training and experience that enormous progress has been made, at an ever-increasing rate, in the mineral industry, particularly in this Century. We know that the mineral industry has played a very major role in providing the means by which so many more people survive to live longer, healthier and more interesting lives, than ever before. Indeed together with the oil and gas industry, which is an integral part of the mineral industry but has achieved its own commercial dis- tinction, it is fair to claim that the mineral industry has played the major role in providing the means for the advancement of the human quality of life.

Jan 1, 1988

Differences in the assay results of replicate samples engender doubts on the reliability of ore sampling and of assaying procedures. An analysis of variance is a technique to estimate the variability at each level of the procedures. In an example, the variability of one-metre core samples was far greater than that of the assaying technique.

Jan 1, 1976

Efficient performance of pulp lifters to discharge ground rock is critical to the effective performance of SAG and AG mills. The paper covers developments in the design of pulp lifters and associated grates, of both conventional straight-radial and curved types, and of the inner discharge cone. Issues covered include the discharge performance of both the slurry and rock components of the discharge, reverse flow back into the mill through open grates and backflow down the pulp lifters of material that fails to discharge from the mill. The design experience is interpreted in the light of developments in particle flow modelling of the flow of charge in pulp lifters.

Jan 1, 2004

By Ruffles B. R

A computer simulation has been developed to model the flow of copper ore in Isa Mine. It simulates extraction of copper ore from the 1100 orebody by load-haul-dump (LHD) units to ore passes, haulage from chutes on 19 level by Rockflo trains to crusher bins, crushing and hoisting. It can assess in terms of the tonnage and head grade of ore hoisted, the effect of varying operating strategies, as well as measur- ing shortfalls in required capacities of any of the operations (extraction, hauling, crushing and hoisting). The simulation was designed as a modular, deterministic, steady-state model with parameter input allowing complete flexibility in its use. Queuing theory is used extensively to evaluate the effect of interference at potential bottlenecks. The model has been used to determine the effect on production of varying train sizes, maintenance policies on the haulage circuit, orepass capacities, and extraction operations.

Jan 1, 1974

By Hosking JW, Muir DM, Ruane M, Smith I. Hinchliffe WD

Maintaining carbon activity is critical to the satisfactory recovery of gold in the Carbon-in-Pulp (C.I.P.) process. Reduced activity can lead to gold losses in tails and lower tonnage throughput.Carbons from a number of W.A. C.I.P. circuits have been examined for the extent of fouling by inorganics such as calcium, magnesium, copper, nickel and silicon. Many of these carbons have exceedingly low activity leadingto low gold loading and excessive contact times. The relative importance of these fouling agents and cyanide levels on carbon activity is discussed. Mathematical modelling shows that relatively small improvements in kineticactivity lead to much lower tank volume require-ments and carbon residence times.

Jan 1, 1984

Uniaxial compressive strength and Young's modulus values measured in the laboratory on NX diamond drill cores were examined statistically to bring out any significant differences between different locations in the mine which might require special treatment in subsequent photoelastic analyses of the mine layout. Correlations were sought between the strength and modulus and various other features of the rock. The estimated mineral content of the core correlated with the modulus of the core, but the range of modulus values was too limited to show any strong correlation with compressive strength.Strength in the vertical direction was found to be significantly higher than in the horizontal direction and the same pattern was followed by the moduli, but was less pronounced. It was concluded that, whilst the modulus variations were significant, they would not invalidate any photoelastic studies.

Jan 1, 1969

By Houghton BF

Ruapehu is an extremely active andesitic composite volcano, built in at least four cone- building episodes over the last 250 ka. The volcano was constructed by a variety of extrusive and subplinian, strombolian, phreatomagmatic and dome-related explosive eruptions from summit, flank, and satellite vents. The volcano may be subdivided into the cone itself, of volume 110 km3, and a surround- ing epiclastic ring plain of similar size. Four facies associations can be recognised at Ruapehu,-two each on the cone and on the ring plain. Neither cone nor ring plain provides a complete record of the history of the volcano. The cone is dominated by the products of extrusive eruption, as primary pyroclastic deposits are seldom preserved, being rapidly removed by erosion from the steep water- saturated and/or snow-covered flanks of the cone. The ring plain consists of the products of mostly explosive activity forming an alter- nation of primary pyroclastic fall deposits and material transported from the cone by lahars, floods and debris avalanches and then rapidly reworked in sediment-choked hyperconcentrated Streams.

Jan 1, 1987

Conceptually coal reserve assessment is simple but in practice it presents many problems. These arise from the origin and geological history of coal seams and from the diverse nature of the coal itself. The suitability of a coal for a particular use depends upon its type and so sheer quantity of reserves does not guarantee the adequacy of coal reserves for all requirements. Codes have been formulated to counteract the effects of subjectivity in reserve assessment. The code for calculating and reporting coal reserves published by the Standing Committee on Coalfield Geology of New South Wales has wide acceptance but the Committee itself recognises that it has shortcomings. Currently the Committee is engaged on the commendable but difficult endeavour of formulating a code that will meet the needs of scientific rigour and professional and commercial ethics and that will allow the specification of an assessment method without constraining it. It is generally agreed in the coal industry that the assessment of coal reserves can not conveniently be incorporated into codes formulated for other resources.

Jan 1, 1979

During the post war era, the requirements of the "Third" World for modern civil works, energy and industry, coupled with an insistence that these capital installations are understood and controlled by indigenous people, have crea- ted a demand and flow of technology from those countries with well developed skills. Thus has grown a real trade in technology - an activity in which consultants play an important role. An indication of the magnitude of this trade is given, together with an outline of some of the special problems. Australia is shown to be dis- advantaged and has been slow to offer the incen- tives to consultants which other countries offer.

Jan 1, 1975

Tonnes per Hour - Kilowatts per Tonne Tonnes of Mesh Size Produced Kilowatts per Tonne of Mesh Size Produced - Terms often heard in discussions of grinding mill and grinding circuit performance. All of them only tell a partial story as none of them relate to a fixed reference or overall standard measurement. Tonnes per Hour gives the production rate relating it to a specified or desired rate set as a goal or objective. As such it does not take into account changes in feed size, product size or grindability. Kilowatts per Tonne which accurately stated is kilowatt hours per tonne brings power consumed into the picture which is related to grindability but still does not take into account changes in feed size and product size without which power changes do not necessarily reflect the complete effect of changes in Grindability.

Jan 1, 1978

North Stradbroke Island is a large sand mass offshore from south east Queensland. Dredging for mineral sands commenced there in 1956 and the rehabilitation discussed in this paper was commenced in 1967. The frontal dunes have a long history of instability, with little vegetation prior to mining. Re-establishment of the naturally stable contours is essential, and their rehab- ilitation is described. Vegetated high dunes present different problems requiring attention to regeneration of the native species. Methods developed over the past eight years are proving successful.,

Jan 1, 1976

Biologically-mediated phenomena are involved in many of the natural processes by which mineral deposits are formed and ore bodies transformed and degraded. They may facilitate the environmentally-damaging effects of mining and mineral-processing operat- ions. Under contrived and controlled conditions, however, these phenomena can form the basis for economically- attractive processes for the recovery of metals from low-grade deposits by dump, heap or in situ leaching. They have application also in processes for the regeneration of leaching reagents and some potential for'-the recovery of metals from dilute solution. The micro- organisms concerned are potential sources for the production of novel flotation and solvent-extraction reag- ents. Perhaps the greatest opportunity for biotechnological processes in min- ing and metallurgy lies in the possib- ility of the evolving of novel proced- ures for the substantially complete recovery of metals from process tail- ings by the unlocking of recalcitrant and complex mineral assemblages, and for the beneficiation of some mineral materi,hls.

Jan 1, 1982

By Quast K. B, Newell R, Caterford J. H

The most common reason for gold-bearing deposits being refractory is the presence of sulphides; in many cases these interfering minerals contain arsenic, antimony, or other environmentally-sensitive elements. A number of processes have been proposed or developed for pre-oxidation of interfering minerals. In most cases developers have focussed on gold recovery and capital costs, with relatively little data on the deportment or form of these potentially harmful elements. This paper surveys recent work connected with pressure pre-oxidation processes. Data from pilot plant treatment of refractory gold materials, using the nitric acid Redox process, is discussed along with the attendant flowsheet and engineering implications. Four refractory gold-bearing materials have also been tested at the University of South Australia for arsenic and antimony deportments.

Jan 1, 1991

By Silitonga M

Generally, the acceptable parameter for predicting the intensity of ground vibration due to a blast is the amount of explo ive u ed and the distance from the explo ion. A eries of closely controlled tests were carried out and it was observed that the degree of confinement or burden of an explosive charge play an important role in the variation of the transmitted magnitude of the shock wave through the ground.The intensity of the shock wave increases with burial depth or with greater confinement of an explosion until a critical depth is reached.Beyond this critical depth, the magnitude of ground vibration remain constant. This is an important finding, which explains the anomalies between the expected level and the monitored ground vibration in a particular situation.

Jan 1, 1984

By D Jones

The development, piloting and engineering design of an innovative water treatment system for process water produced by a uranium mine mill are described. The process incorporates lime/carbonate softening (Stage 1), reverse osmosis (Stage 2) and biopolishing (Stage 3) to produce water of quality suitable for release to the receiving environment. Comprehensive performance data are presented for each stage. The unique features of the proposed process are: recycle of the lime/CO2 softening sludge to the uranium mill as a neutralant; potential use of power station off-gas for carbonation; and the potential recovery and recycle of ammonia from the RO reject stream.

Jan 1, 2003

The results of iron ore exploration in Western Australia between '1961 and 1964 are outlined, with particular.reference to the Hamersley Iron Province. Exploration during: these three years has increased the known resources of the-,Statle from 275 million tons to almost 9,000 million tons of high- grade hematite ore. In addition, reserves of lower-grade .pisolitic limonite ore are-estimated to amount to 6,000 million tons. The origin and characteristics of the different types of ore is discussed,

Jan 1, 1964

Water is important commodity in the mining industry. Water is used in the many stages of mining from the exploration stages and drilling, to mine development and operation and finally throughout mine rehabilitation and post mine activities. With the use of water throughout the life span of a mine, its management is an important component in the operation of any mine. Unfortunately the use of water within the operations can be one of the major sources of pollution generated from a mine. Such contamination can occur via numerous mechanisms including ground water flow, over land flow and accidents. Contamination may occur in any stage of mining operations, for example a leaking or failed tailings dam. With the above in mind, the paper presented will focus upon the use and management of water in the mining industry: ownership rights of water û common law as well as legislative rights; a review and analysis of the existing Queensland legislation and its mechanisms for the protection of water pollution from mining operations; and conclusions drawn from the paper relating to the Queensland legislation.

Jan 1, 2003

By D von Horn

Mineral sand orebodies are typically mined for their TiO2 content. Increasingly over the past 30 years, the major mineral focus has shifted from natural rutile to ilmenite and an acceptance that the latter generally needs some form of upgrading for economic conversion into TiO2 pigment. This upgrading obviously has a cost, and in conjunction with diminishing mineable feed grades, results in higher cost TiO2 units for chloride route Pigment Plant feedstocks. The net cost of feedstock can be significantly influenced by the recovery and sale of accessory minerals and by-products from the processing chain to the extent that some producers have the potential to achieve a zero net cost. Whilst slagging plants typically reduce net cost from rutile, zircon and pig iron revenues, operations supporting Becher type synthetic rutile operations have been limited to revenues from rutile and zircon only. A range of alumino silicate minerals show industrial potential, as does activated carbon, iron oxide and gypsum, by-products of the synthetic rutile process. Tiwest is a good example of a company maximising revenue from the accessory minerals as well as from by-products of the synthetic rutile process.

Jan 1, 2001

As Coal Mining Areas develop, problems relating to strata control increase. The "easy" coal has been extracted and the future development lies in the direction of greater depths of cover and more difficult strata conditions. To provide solutions to the problems encountered the techniques of constructing and testing physical models have been developed and refined. With a sound knowledge of model theory allied to practical experience, mining research engineers use physical cemented material models to examine, assess and solve mining problems relateu to strata behaviour and environment. For a model to provide the answer to a particular mining problem it is essential that as much information as possible be obtained from the mine or area of a mine which the model is to represent. Details relating to the strata, geological malformations, and the stress environment must be collected and collated to ensure reliable results.

Jan 1, 1976

By Conley R, Payne I

The Vickery Coal Mine commenced open cut mining operations in May 1991. All overburden and interburden is drilled and blasted for excavation by dragline or hydraulic excavator. The mode of operation adopted from the feasibility studies requires that throw blasting of the overburden be used to assist dragline productivity.This paper reviews the development of the drilling and blasting practices with particular emphasis on the throw blasting of the overburden and optimisation of costs. This review includes analysis of the pre-production drilling and blasting feasibility studies by comparison with actual results.

Jan 1, 1992