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By L D. Redden, M G. Nelson

Mechanical flotation machine design is typically based on hydrodynamic analysis, with scale-up calculated by geometric proportionality. End users often specify and purchase machines on the basis of retention time, characterised by the æ$/m3Æ approach; they may also consider the manufacturerÆs installed base. In some applications, end users also consider specific energy and the impact of energy consumption on operational costs. In other cases, a decision may be based on machine type (forced-air versus self-aspirating) and perceived metallurgical or operational advantages of one machine type over the other. With regard to metallurgical performance efficient bubble-particle contact is very important and is primarily influenced by two factors:the concentration and size distribution of bubbles in the machineÆs contact zone (the volume enclosed by the disperser); and the number of times that slurry is pumped through the contact zone. The second factor is a function of the machineÆs pumping rate and its retention time. Field data show that pumping efficiency is independent of aeration rate. In this paper, a new dimensionless number for the characterisation of flotation efficiency is presented. The contact frequency number (CFN) is defined as the number of times a given volume of slurry passes through a machineÆs active contact region, and is given by: CFN Qp/Qf, where:Qpis the pumping rate through the contact regionQfis the volumetric feed rate to the machine

Jan 1, 2005

The first grant of land rights in Australia was pursuant to the Aboriginal Land Rights (Northern Territory) Act 1976. That Act has been at the core of the dispute between land rights and miners' rights. The mining industry believes that the Act, in giving a right of veto to Aborigines with respect to exploration and mining on Aboriginal land, has been responsible for a stagnation in exploration amd mining activity in the Northern Territory. In February 1985 the Commonwealth Government released for public comment its preferred model for national land rights legislation. The model has been opposed by the mining industry because it believes, first, that land rights is a matter which should be left to the States and, secondly, that the detailed mechanisms contained in the model constrain the industry in the manner of the Northern Territory legislation. Aboriginal leaders have opposed the model because it does not, in their view, measure up to undertakings given by the Commonwealth Government and, in addition, it provides for amendments to the Northern Territory legislation which are likely to result in the loss of the Aboriginal veto right. Are land rights and miner's rights compatible? The answer is yes provided all parties, including Governments, are prepared to talk and compromise and Governments recognise that the grant of land rights and any control by the Aboriginal people of exploration and mining on their land is not a substitute for raising the living standards of Aborigines as a significant group of disadvantaged Australians.

Jan 1, 1986

By S M. Denn

The Cawse nickel-cobalt operation is situated 50 km NW of Kalgoorlie in Western Australia, at latitude30o22'30'' south and longitude 121o08'30'' east on the Kalgoorlie 1:250 000 geological map sheet (SH 51-9) (see Figure 1). The project is owned and operated by Centaur Nickel Pty Ltd (CTR) and was the first in Australia to commercially produce nickel metal and cobalt sulphide through pressure acid leach (PAL) technology. Cawse has a total resource base (all categories of resources + reserves) of 213 million tonnes Mt at 0.7 per cent Ni and 0.04 per cent Co, comprising 127 Mt at Cawse Central which is 100 per cent owned by CTR and 86 Mt at Cawse Extended where CTR has a 80 per cent equity. Cawse Extended is located immediately to the northwest of the Cawse Central leases. All current reserves (proved and probable) of 30 Mt at 1.0 per cent nickel are contained within Cawse Central. In addition the Siberia project area 20 kilometres to the NW has a resource of 63 Mt at 0.7 per cent Ni. Cawse is a dry laterite deposit, with nickel and cobalt hosted by iron and manganese oxides. Cawse Central mineralisation extends over a ten kilometre strike length, with three pits currently being mined. The Bunyip pit has the premier nickel and cobalt grades within Cawse Central. There are seven dominant lithology types forming mappable units within current pit exposures. Four of these units are host to nickel and cobalt mineralisation. Ore types are defined as Upgrade, Grind and Non-upgrade, depending on their physical characteristics with respect to the treatment route. Mining commenced in February 1998. To the end of calender 1999 the operation has produced 2100 tonnes nickel plate and 470 tonnes of cobalt as a cobalt sulphide product. Future production will target 9000 tonnes per annum Ni metal and up to 2000 tonnes per annum Co, based on processing 500 000 tonnes of ore per annum.

Jan 1, 2000

An exploration and preliminary mine design contract was undertaken in Thailand to establish whether adequate lignite resources existed for the addition of future power generation plant through to the year 2000. The lignite ranges in heat value from 14 to 24 MJ/Kg (air dry basis) and occurs in 2 major seams consistituting measured reserves of 536 Mt (with an ash cut-off level of 45 % on an air dry basis) and a strip ratio of 4.1 bank cm/t. The paper describes the pre-planning, programming, equipment used, project management, logistics and exploration methods adopted to undertake the contract in a monsoonal area using Australian drilling and geophysical contractors.

Jan 1, 1983

By Corbett GJ

The Bulolo Graben represents an intra-arc rift formed by activa- tion of transfer structures in an extensional setting formed be- tween the eastern and western sectors of the New Guinea Origin. Crustal thinning has facilitated the emplacement of dacitic Edie porphyry intrusions, locally as flow dome complexes, phreatomagmatic (diatreme) breccias and the Bulolo ignimbrite/ agglomerate as an extrusive equivalent of the Edie Porphyry. Gold mineralization is localized along intra-graben structures, com- monly at the intersection with cross structures and occurs in sub- sidiary dilational fractures and not the localizing major structures. Gradations are apparent in the styles of mineralization according to the degree of erosion of the hydrothermal system. Hamata occurs as the deepest mineralization of the quartz-sul- phide style Wau, Hidden Valley, and Edie Creek are dominated by carbonate-base metal styles. Kerimenge grades from quartz sulphide through carbonate-base metal to epithermal mineraliza- tion, the latter style also being present in the periphery of Edie Creek. Here, pre-existing fractures of the Edie Creek Structural Corridor have been reactivated by movement on NS structures to form the ore-hosting dilatant lodes. Fluid flow may have been from the vicinity of the Nauti diatreme margin and along the vein System.

Jan 1, 1997

By R van Berkel, J Lay, D van Beers

The development of regional resource synergies in intensive areas with concentrations of minerals processing industries provides a significant avenue towards sustainable resource processing. Gladstone (Queensland) and Kwinana (Western Australia) are two of AustraliaÆs major heavy industrial areas. There are a number of successful regional synergies in both areas. In addition to the existing regional synergies in both areas, more potential synergy opportunities appear to exist which, upon implementation, could benefit industry, the environment and the community. To further enhance the development of such potential regional synergies, the Centre for Sustainable Resource Processing (http://www.csrp.com.au) commissioned research projects to facilitate the identification of potential synergies and assist with their implementation in both regions. This paper presents a selection of specific examples from both regions to illustrate the sustainability benefits from regional synergy developments. Although the composition of industries in the Gladstone and Kwinana regions is different both in terms of geography and industry diversity, similarities in synergy developments for both regions are apparent. Consequently, the examples discussed in this paper are organised around the key themes of water, energy and inorganic by-products. Comparison on a theme basis highlights success factors of successful synergies and demonstrates the range of benefits resulting from their implementation.

Jan 1, 2006

For the last 4 years political leaders have found a new subject on which they can safely generalize wihout creating opposition. That sub- ject is commodity prices. Since the four-fold increase in OPEC crude oil prices, public atten- tion has focussed as never before on the subject of commodity prices. To advocate stabilizing com- modity prices is akin to supporting motherhood or peace or better schooling. Everyone gives lip service to the concept that stable commodity prices are desirable. It is easier to state the principle than to achieve it. Prices that are stable in terms of one currency may be clearly unstable in terms of a different currency. This has become a troublesome matter since 1971, when the world's leading trading currencies were set free to float in relation to each other. To illustrate: consider copper prices in the interval between the end of 1974 and the end of 1977. During those 3 years, the copper price in pounds sterling on the London Metal Exchange rose by 25 per cent. During that period, however, in terms of the USA dollar equivalent, the price was unchanged. And during that period, in terms of the German mark equivalent the price shrank by 13 per cent while the Japanese yen equivalent f.11 1k

Jan 1, 1978

Background A recent development in many industries,' including the mining industry, has been ever increasing acceptance and adoption of extended (12-hour) shifts and compressed work cycles compensated by more time off work by employees between cycles. In the Western Australian mining industry development of `long-distance-commute' (LDC) coincided with adoption of 12-hour rotating shifts. Preludes to LDC were the `construction-style' rosters with two crews plus allowance for annual and sick leave relievers working the statutory 13 consecutive shifts followed by one shift off. Crews rotated day to night shift weekly or at fortnightly intervals. Average hours of 72 to 78 per week were common. The author had personal experience working these rosters in the East Pilbara of Western Australia from 1977 to 1982. Workers tolerated these rosters until a suitable combination of frustration, boredom, despair and the `Five Grand Fever' triggered them to `pull the pin' and head for relaxation in Bangkok, Manila, Nimbin, or Margaret River according to their personal tastes.

Jan 1, 1996

The sulphide ores of the Kalgoorlie goldfield have long been looked upon as' refractory, involving special metallurgical treatment. For many years two kinds of treatment have been practised-(l) wet treatment, including fine grinding, amalgamation or concentration of the free gold, concentration of the sulphide minerals with subsequent roasting and cyanidation, and cyanidation or bromo-cyanidation of the residue from the concentrating operation; (2) dry-crushing of the ore and roasting the whole of thecrushed ore, amalgamation of the gold in the calcine during fine grading, followed by cyanidation. The wet treatment was advanced a stage further when, in 1929, the Lake View and Star Ltd. adopted large scale flotation. As a consequence, however, further metallurgical problems were introduced. This paper covers the investigation, ,of one of the most prominent of these problems.Flotation preceded by strakes was satisfactory to a point.The flotation concentrate consisted largely of auriferous pyrite and tellurides, and the gangue minerals in the concentrate were practically barren.Several sources of loss of gold values were, however, found to be associated with this circuit, viz.-(a) There was the loss of gold in the flotation tailing.(b) Loss by dusting during roasting of the flotation concentrate.(c) Loss of gold in the cyanided residue.

Jan 1, 1937

Pongkor Gold Mines is one of seven units of production owned by PT Aneka Tambang (State owned mining company). The mine is located in the western part of Java Island, Indonesia. It is in the Bogor District and approximately 110 kilometres to the south of capital Jakarta. It is located in very steep hilly terrain intersected by many river valleys and the mine site is approximately 500 metres above mean sea level (see Figures 1 and 2 - Mine location map and picture)

Jan 1, 1997

By D Guibal, J Vann, M Harley

Many sample value distributions are highly skewed and present variograms with high relative nugget effects and/or short-range structures. In consequence, significant deskewing of the histogram and variance reduction occurs when transforming between sample and block support, where blocks are of significantly larger volume than samples. When making estimates in the mining industry we usually wish to estimate on the basis of block support rather than sample support. The selective mining unit (SMU) refers to the minimum support upon which ore/waste allocation decisions can realistically and practically be made. The SMU is usually significantly smaller than the sampling grid dimensions, in particular at exploration/feasibility stages. In a non-linear estimate, for each large block (by convention called a æpanelÆ) we estimate the proportion of SMU-sized parcels above a cut-off grade threshold. A series of proportions above cut-off defines the SMU distribution. Use of such non-linear estimates reduces distortion of grade-tonnage curves and provides a better basis for mine planning and economic decision-making. At present, Multiple Indicator Kriging (MIK) is the most widely used technique for performing estimation of recoverable resources. MIK is not the only approach available and it has some potentially serious limitations. The MIK technique is described and a number of theoretical and practical implementation issues are examined. In particular: MIKÆs assumptions about spatial distribution of grade; the behaviour of indicator variograms; application of change of support models; order relationship problems; and modelling the tail of the distribution. Some simple tests are described which allow us to determine the suitability of different estimators for a given deposit and criteria to identify a preferred estimator are also examined. Uniform Conditioning (UC), an alternative estimator which may be used instead of MIK, is described.

Jan 1, 2000

By Ward B

Central Colliery was developed to exploit large underground reserves in the German Creek lease. It was planned from the outset as a retreating longwall operation and is the first longwall mine in Queensland. Longwall mining is not new to Australia but all previous experience has been confined to the coalfields of New South Wales. There was no precedent for longwall extraction in the markedly different geological setting of the Bowen Basin in Central Queensland. Various investigations were thus carried out during the initial development of Central Colliery, prior to the installation of the longwall, to ascertain the geotechnical characteristics of the coal seam and the adjacent strata and to predict the performance of the heading and pillar design as mining proceeds to depth. Laboratory tests showed the coal to be weak with an unconfined compressive strength of 9.6 MN/m2. Site inspection and geophysical correlation revealed a shear zone and extensive intraformational shear planes in the seam. The latter were found to exert a controlling influence on rib reaction in the headings. This behaviour was predicted by finite element modelling of the development headings which indicated that mining induced stresses in the coal would be relieved by block movement of the ribs. A chain pillar width versus depth curve was established for yielding pillar design based on empirical and computational methods. This gave pillar widths from 25m to 48m over the proposed depth range of 150m to 300m. Finite element modelling of the 25m pillars chosen for the first gateroads confirmed the overall stability of the design but suggested that rib spall could be significant in the adjacent tailgate. (1) Chief Mining Engineer, Capricorn Coal Management Pty. Ltd., German Creek Mine, Queensland (2) Senior Engineering Geologist, Coal Division, The Shell Company of Australia Limited, Melbourne

Jan 1, 1986

By B Newcombe

From many years practical industrial experience the author has drawn together a list of the key points to consider when embarking on a large-scale geometallurgical project. Fundamental aspects which must be considered include (but are not limited to):understanding the variability of the orebody both laterally and with depth;comminution properties and variability;flotation properties, requirements and variability – differing ore zones may have substantially different requirements for optimal performance;the role of texture – the consequences of both grain size and distribution and how the circuit will handle these;realistic expectation in terms of the financial requirements and time frame results are required within; andintegration of, and communication between key personnel within the various departments of the site (mining, geology and processing) is a fundamental aspect of any geometallurgically based processing system. An example of a highly complex nickel sulfide ore will be used as the basis of discussion.

Sep 5, 2011

By Sakai S, Suga S, Bisque RE

Soil gases were collected on activated charcoal, analyzed by computerized mass spectrometry and treated with multivariate statistical pattern recognition to determine the diagnostic geochemical signature associated with the Okuaizu Geothermal Field in Japan. From this a geothermal model was developed and compare to 175 "unknown" samples in a 250 m spaced grid over 30 1Qn2 mapping the areas with a matching geochemical character. Faults and fractures were generally located by the presence of high molecular weight components. Following the initial survey, the faults in two specific areas were precisely located by a second survey with samples at 10-30m spacing. Where earlier geochemical surveys had placed anomalies 1-2 Km northeast of the geothermal center, the fingerprint survey accurately mapped the system and detected several faulted zones. It was not misled by hot springs located away from the geothermal System.

Jan 1, 1987

By T Roberts, D Faulkner, G Watt

Traditional mechanised resin rock bolting in hard rock underground mines requires the installation of resin capsules into a pre-drilled hole prior to the rock bolt being spun into a hole to mix the resin and set the bolt in place. In poor rockmass conditions, especially at depth or in highly altered faults and shears, the condition of the holes often deteriorates as the poor ground around it unravels and falls into the hole. This results in partially or fully blocked holes that either damages the resin capsule when they are being inserted into the holes or prevent it entirely until the hole is continuously cleaned of debris. This deterioration of the hole condition, and continuous need to clean and re-drill holes, also increases the diameter of the hole which in turn affects the continuously mechanically coupled anchorage mechanism of the rock bolt to the rockmass as there is simply not enough resin in the hole to fill the annulus between the bolt and the rock. This results in a large increase to critical heading cycle time and, more importantly, results in the rock reinforcement not performing as per design specification and increases the risk of instability. To overcome the quality control issues with resin bolt installation in poor ground, a single pass drill, install, inject and tension self-drilling resin bolt application was designed and implemented for use in such conditions. This system allows the operator to inject a two part polyester resin through a self-drilled hollow bolt to mix and fully encapsulate the rock reinforcement. The self-drilling bolt allows for post injection of the hole after the bolt has been installed into the rock and gives the operator manual or automated control on the amount of resin used in the hole to ensure complete encapsulation and continuously mechanically coupled anchorage to the rock. This allows the reinforcement to work as designed and provide the Geotechnical Engineer extra quality control confidence in these conditions. The implementation of this single pass resin bolting system resulted in significant decreases to the resin bolting cycle time and rock bolt quality control failures. In this paper the design, implementation and embedment into the development cycle will be discussed and the in situ quality control checks used to validate the increase in rock bolt installation quality will be shared. CITATION:Watt, G, Roberts, T and Faulkner, D, 2018. Single pass drill, install and inject self-drilling resin bolt application in poor ground, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 323–343 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Kurita K, Tanaka T

In order to clarify the gas flow and motion of coke and reaction in the raceway, the mathematical raceway model was developed. This model consists of the equations of momentum and continuity of gas and coke. The simulated results were compared with the results of the cold and hot experimental model. The relationship between the blast volume and the raceway size, the pressure distribution and the velocity distribution of coke are in good agreement with the experimental results. Moreover the equations of reaction and heat conservation were simultaneously calculated with the dynamic equations. Distributions of gas composi- itions and temperature were simulated and found to be in good agreement with the distributions of gas compositions of CO, CO2 on the tuyere level measur- ed in the hot experimental model.

Jan 1, 1981

The diverse nature of inadvertent mine fires does not lend them to general treatment. But evolving from the unfortunate fires over past years is a simple principle in dealing with all fires to bring combustion under control. Control, in brief, means that the products of combustion, themselves possibly still with fuel values, are not revitalised by addition of fresh air. There are problems with fire- fighting, especially with water, as this may lead to production of CO and H2. Panel ventilation upstream of the fire must be controlled to direct all air over the fire. Some advantages in fire fighting are found by the use of "sails". Early diagnosis of fires and early treatment are essential for safety of personnel and safeguarding and recovery of property. Preparedness extends to up to date documentation, but first hand knowledge also is invaluable to the diverse personnel gathered to fight a fire, and in the decision making Involved.

Jan 1, 1981

By P A. Grossman, J H. Rubinstein, M Brazil, D Whittle

Many ore reserves are harvested by a combination of open pit and underground mining methods. In these cases, there is often material that could be mined by either method, and a choice has to be made. The area containing this material is referred to as the transition zone. Deciding where to finish the open pit and start the underground mine is referred to as the transition problem and it has received some attention in the literature since the 1980s.In this paper, we provide a review of existing approaches to the transition problem encompassing: graph theory-based optimisation employing an opportunity cost approach, heuristics and integer programming. We also present a novel opportunity cost approach, that takes into account a crown pillar, and show how the new approach can be best applied through the unconventional application of an existing mine optimisation tool.CITATION:Whittle, D, Brazil, M, Grossman, P A, Rubinstein, J H and Thomas, D A, 2016. Determining the open pit to underground transition – a new method, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 731–742 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Hagan T. N

Quite apart from economic considerations, the following performance parameters must be considered when selecting an explosive for a particular blasting operation. 1. total energy yield/kg, and more particularly, strain energy/kg and bubble energy/kg of charge 2. charge weight/m of blasthole 3. sensitivity of the charge 4. water resistance of the charge The effective division of an explosive's total energy into strain energy (SE) and bubble energy (BE) is explained as is the influence of each energy component on blast results. Because some rocks require a high strain energy for effective breakage, while others are most satisfactorily fragmented by bubble energy, values of SE and BE are more meaningful than those of total energy. Unfortunately, our extensive knowledge of the effects of certain variables on total energy has not yet been completely supplanted by the influence of these variables on SE and BE values. Relative SE/kg and BE/kg values are presented for a range of explosives. The 'charge density of ammonium nitrate/ fuel oil (ANFO)-type explosives is essentially constant throughout the length of the charge; because of their compressibility, slurry

Jan 1, 1974

By Cotton R. E, Cox R

Digger Rocks is one of several nickel-bearing sulphide deposits localised within komaLiitic volcanics of the Forrestania Greenstone Bell within the Archaean YiIgam Block of Western Australia. Exploration and evaluation to April 1990 have delineated a resource, at a nominal cut-off grade of 0.5 per cent Ni, of 1.9 Mt at 1.1 per cent Ni within a lensoid sulphide body which strikes NW, dips 50°SW, and occurs at a depth of 30 - 110 m below surface. There has been no production from any of the Forrestania nickel deposits to-date. The deposit, comprising both disseminated and massive sulphides, has maximum dimensions of 400 m strike, 115 m vertically and 90 m true width. Generally the massive sulphides occur at the base of the disseminated sulphides, on or close to the base of the Digger Rocks dunite. The two main massive sulphide lenses have maximum dimensions of 120 m strike, 75 m vertically and 16 m true width (northern lens) and 60 m strike, 25 m vertically and 4 m true width (southern lens). The average grades of the massive and disseminated sulphides are 5.9 per cent i and 1.2 per cent i respectively. The massive sulphides generally have sharp hangingwall and fOOlwall contacts and display strong internal grade anisolropy.The massive sulphides are mainly within the supergene zone and consist of violarite, pyrite and marcasite. The disseminated sulphides are mainly within the primary zone and consist of pentlandite, pyrrholite, pyrite and minor chalcopyrite. Alteration zones, up to six in number, are complex in detail. The sulphides are capped by an average of 30 m of sub-economic, leached, siliceous, oxidised material.A genetic model for the deposit is described which places Digger Rocks in Category 2 (sulphides in large layered dunite bodies) of the latest classification of komatiitic nickel sulphide deposits in the Yilgam Block of Western Australia by Hill and Gole (1990).

Jan 1, 1992