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By L M. Foster, J R. Kellett, G A. McMah

The Great Artesian Basin (GAB) contains one of the largest reserves of fresh water in the world. The volume in storage is enormous, being estimated at nearly 65 000 million megalitres (ML). Development of this resource, dominantly for the pastoral industry, began in the late-1800s and quickly accelerated. With exploitation of the resource, artesian pressures declined almost as rapidly. This loss of head is a result of the total discharge from the basin and much of this discharge is waste of water. The waste through uncontrolled bores and inefficient distribution systems still amounts to about 75 per cent of all discharge. However, the volume in storage has hardly been depleted. The major concern is the effect of withdrawal on artesian pressures. Due to the size of the Basin, the relatively flat gradients and low permeability, the movement of water through the aquifers is extremely slow and independent of recharge. Hence, the normal concepts of sustainable yield (ie discharge should equal recharge) cannot be applied to the Basin as a whole as travel times do not allow for the effect of recharge to be seen away from the outcrop areas within management timeframes. The large volume in storage, though, can provide an extensive buffer to the impacts of temporary water needs. This effect should be considered when assessing the acceptability of fixed life projects such as mines and the extracted volumes from their operations. Identifying a sustainable yield involves balancing the acceptability of the economic, environmental and social costs with the associated discharge and fall in head, to arrive at an acceptable balance.

Jan 1, 2003

By Quinlan M. J, Ratcliffe J. S

Chemical kinetics is a dependent process which usually correlates the rate at which a reaction proceeds with the mechanism descriptive of the manner by which reactive particles interact. Given the latter, the object gen- erally is to find the reaction rate dependency in terms of an intensive property of the system - number of reactive particles present, and of the energetics of the system - usually temperature. Chemical kinetics depend on a dem- onstration that reaction considerations alone control the phenomenological process under study. For these rea- sons, chemical kinetics are usually involved in homogeneous gaseous systems. Even in liquid homogeneous sys- tems earliness or lateness of reactant mixing rather than chemical kinetics may be controlling. Considerations of transport phenomena are involved in heterogeneous systems and often control the observable rate:an additional problem in such systems is to apportion the rate due to mass transfer - usually a linear process - and that due to reaction which may be linear or non-linear. Experimentally, conditions are often chosen so that only one consideration controls but this becomes more difficult where solid phases are involved. Kinetic modelling involves considerations of chemical kinetics, transport phenomena, and factors attributable to the physical environment in which the process takes place. The latter two considerations may be quite different as between experiment and plant. The kinetic model may be a mathematical representation of a conceptual mech- anistic model of the reaction. Alternatively, it may be an empirical relationship resulting from, for example, some curve fitting procedure applied to experimental data. The latter approach may be necessary where the system is particularly complicated.

Jan 1, 1975

Although forty-seven years have passed since the by-product coke oven made its successful commercial appearance, it is only during the past fifteen or twenty years that this system of coal carbonisation has advanced rapidly to its present position ofabsolute supremacy.Early designs of by-product ovens proved more or less faulty, and the coke produced was so inferior to coke made in beehive ovens that there was a natural hesitancy on the part of coke producers to invest large sums of money in installations of by-productovens of doubtful utility-more especially in view of the fact that beehive ovens could be erected cheaply and operated by non technical labour for the production of high-grade coke under the most variable conditions of trade.Surely and steadily designers brought forward by-product ovens of improved type, coupled with more efficient apparatus for the recovery of by-products, but still the industry lagged, due almost entirely to the insistence on the part of coke users that the qualityof ordinary beehive coke was vastly superior for metallurgical operations to the best coke produced from by-product ovens. So deep rooted was this prejudice that only the passage of time could eradicate it. That it has successfully done so is strikingly illustratedin the following statistics:

Jan 1, 1928

By Nichol R

- PART A The Hoppers Crossing Pumping Station is one of the principal components of the Western Trunk Sewer Project which replaces the 90 year old Main Outfall Sewer and will convey 60% of Melbourne's sewage flow from Brooklyn to the Board's Farm at

Jan 1, 1987

Laboratory high tension roll separation and the commercial machines available for this purpose are discussed. The shortcomings of these machines are indicated and a machine that overcomes some of these undesirable character- istics is described. A procedure for evaluating laboratory high tension roll separation is described. The use of this evaluation procedure in conjunction with the laboratory separation is described with examples taken from the Dunwich and Hexham processing plants of Associated Minerals Consolidated Limited. Evidence that laboratory testwork results may be directly transposed to operating plants is given. A discussion of the effects of variables in high tension roll separation of mineral sand concentrates concludes the paper, and uses in support results obtained in the metallurgical laboratories of Associated Minerals Consolidated Limited, Southport, Queensland.

Jan 1, 1972

By Palmer G, Dennis R, Clark A

The Ravenswood Mine in North Queensland is the first gold mine developed by Carpentaria Gold Pty Ltd, a wholly owned subsidiary of MIM Holdings Ltd. Carpentaria Exploration Pty Ltd began exploration at Ravenswood in 1978. However initial exploration of the main gold producing area (Buck Reef East) commenced in March 1987 when exploration rights to four key leases were secured. A rapid, co-ordinated exploration and development program produced gold from a heap leach operation nine months after the first costeans were dug at Buck Reef East. To treat higher grade ore found at depth in the Buck Reef East pit and the metallurgically more difficult Buck Reef West ore, a carbon in pulp plant was commissioned in May 1988. The mine is currently producing at a rate of approximately 40 000 ounces of gold per year. Ore at Ravenswood is hosted by hydrothermally altered diorites and tonalites of the Ravenswood Granodiorite complex. Alteration is controlled by planes of permeability formed by joints, shear zones and dilational breccias. The complex orebody geometry resulting from these controls required very detailed surface and drill exploration for adequate definition. Carpentaria's need for early cash flow meant that economic, mining and metallurgical considerations governed choices of exploration techniques, program timing, material and data collected. The initial reserve of 1.1 mt @ 2.87 g/t Au was defined by sectional polygonal methods. Grade control is based on geologic mapping and blast hole or channel sample assays. Ore is batched through the crusher and sampled to monitor grade control and mining performance. Minimal dilution has occurred. Gold content is greater than predicted by the reserve. Sprinkling of heaps commenced in November 1987. Changes have been made to the pad design and to the method of heap construction. Heap leach ore is treated at a rate of 400 000 tpa.

Jan 1, 1989

Copper grades of diamond drill hole and development samples are determined in the core shed logging area at Mount Isa Mine using a Bulk Mineral Analyser. All geological and grade data on the copper orebodies is collected and stored on computer file.The raw data can be manipulated interactively using a computer terminal or by input of forms to produce output as computer plots or printouts. Grade distribution of copper or cobalt is obtained by the geologist using a computer kriging package followed by grade contouring. Computer plotted cross-sections and plans of individual stopes or several stopes can be produced showing geological structures, kriged grades at points and as grade contours.

Jan 1, 1985

Jarrah Decline is currently the only underground operation at the Boddington Gold Mine, (BGM). The mine is located 120 km SE from Perth in WA, with mineralisation hosted within deeply weathered felsic and intermediate intrusions and volcanic rocks of the Saddleback Greenstone Belt (Morley and McBride,1995). Open cut operations commenced in April 1987 with a mill throughout of 3.OMtpa. A number of upgrades have since taken place, with the oxide material throughput currently milled at a rate of 7Mtpa. In 1992 a separate circuit, the supergene mill, was commissioned to treat copper material from the open cut and now ore from the Jarrah Decline. Current throughput in the supergene plant is 30,000 tonne per month, with a varied blend according to mill requirements. Total gold production from the Jarrah Decline in 1994 was 60,000 ounces from 90,000 tonne of ore.

Jan 1, 1990

By Aiming Z, Shenyi S, Xialei W

Zhangmatun Iron Mine is situated in the suburbs of Jinan city. Shandong, China. Because of surface environmental constraints, no suitable site can he selected to dispose of mill waste. The full mill tailings must be disposed of underground. This paper deals with the work conducted at Zhangmatun mine to develop a total tailings backfill system, taking advantage of a double- shaft blade mixer and an activating agitator to prepare backfill. Cement and ground slag are added to tailings for strength development. Two scopes have been filled and the pillars have been effectively mined out during the field trial. The application of innovative total tailings backfill technology is a new concept at the mine. Detailed planning has achieved a close integration of mining, milling and backfilling. Full mill tailings, with or without rock, are disposed of underground in a continuous process to fill, totally and systematically, the cavities formed by mining.

Jan 1, 1998

This is the time of year tor the presidential address, and with the present incumbent engaged in the coal mining industry, it will therefore come as no surprise to you that the theme of my address this evening is concerned with coal.There are other reasons for this apart from my contact with the coal industry. At present, coal is supplying considerable overseas revenue at a time when the remainder of the mining market is in a somewhat depressed state. That times will change goes without saying, if history is to be believed.However, so far so good for coal. My first reaction when The Institute indicated its wish that I be president for 1976 was to become deeply conscious of the honour bestowed on me.On consideration, I realized that very few past presidents have been intimately connected with the coal mining industry to the extent of indulging in it for lengthy periods as a full time occupation or, conversely, a part time interest for a long time. It also appears that not one had started their career in the industry. In my case, 'also, there were 8 very interesting years ,as a gold miner and metallurgist before commencing in coal.It therefore seemed appropriate to endeavour to discover ,why this should be so, as coal mining is now a very important part of a very important industry. What were the reasons why the industry took so long to emerge when there were ample reserves of easily accessible coal?Frankie and Johnnie in their bar room epic of the depression years concluded, and I paraphrase, that "their story held no moral, their story told no tale". If my story has such a message, it could perhapsbe construed as reinforcing the oft-repeated dictums, true or false, that "history repeats itself" or "man never learns".Coal mining is by far our oldest major Australian industry except for agriculture. Its history is almost as old as that of settlement:For various reasons, there has been a glamour associated with metal mining ventures which prob...

Jan 1, 1976

The development of the Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves is a significan step towards informing the financial community and the public about the future profitability and risks of investing in resource companies. The Code is also important from the accountants' point of view because it provides them with a well-defined bash for assigning costs or attributing value to the assets of resource companies and hence improving their financial reports. Although reporting to the public is ultimately the responsibility of management, accountants, like geologists, are frequently required to provide information for inclusion in these reports. Jr the last ten years, there has been a considerable refinement in the reporting of mineral resources which can be attributed mainly tc the progress made towards developing the Code. It seems tha the classification and terminology that the geologists have developed are widely used in the annual reports. However, little progress has been made by accountants in improving the financia information. The purpose of this paper is twofold: (a) to outline briefl) some of the major problems in accounting and reporting fo; mining companies and; (b) to examine the potential contribution of the Code in solving those problems.

Jan 1, 1990

By Grant J

In surface mining, significant improvements in efficiency can be obtained through greater control over the formation of the muckpile. By tailoring the muckpile shape and its looseness to the requirements of the excavating equipment savings can be rea- lised through increased production, machine life and reduced maintenance. For instance, one open cut coal mine has recently estimated that a 2001o improvement in its front row throw would realise $320,000/year savings in rehandle costs alone. Previously greater throw has been achieved by increasing the powder factor through increased quantity of explosive or by drill- ing a larger number of holes-both at a significant cost penalty. However a recent series of experimental blasts demonstrated that it was possible to achieve a twofold increase in the distance of throw of a single row blast by simply changing delay timing alone. The Nobel Electronic Delay Detonator was used to provide the timing flexibility and control required for a thorough study of the effect of blast timing on heave. Whilst it is well accepted that the front row of a blast dominates the extent of throw, it was also found that the profile of the blast could be significantly altered. To date, the general consensus has been that the muckpile for- mation from a blast is a function of the blast geometry, the rock type, the explosive and the initiation sequence. Typically the geometry, rock type and initiation system have a far greater impact than the explosive type. This has been demonstrated by many high speed film studies. However the extent of influence via initiation has rarely been fully evaluated, owing largely to the limited control offered by conventional detonators.

Jan 1, 1988

The equity market is now very much within a global village environ- ment, with various exchanges acting as agencies for the big casino. In this predicament, mining companies, who provide the most extensive, but relevant risk assessment information, will be best placed for favoured treatment by potential international investors: But what risk assessment information in summary form can be provided to support a resource/reserve statement? Even more importantly, does "objective" data exist, whose trends will support a resource/reserve state- ment? A prime need of the informed mining investor is to determine whether or not the resource/reserve statement is believable? But more importantly will it be realised? While the implications within the text of the majority of reports on resource/reserves suggests that the estimates are conservative, the record indicates that very few estimates are. In fact, to date, reports claiming to be conservative in respect of the overall grade estimate at a specfic cutoff have not reflected the realised grade at the stated cutoff; it has been more common for the realised grade to be lower than implied by the resource/reserve statement. Further, it is not uncommon for penalty elements to be understated and these components are rarely incorporated within resource/reserve statements.

Jan 1, 1988

A conventional Bucket Wheel Excavator (BWE) system with conveyor transport, mobile tripper and spreader was commissioned at the Goonyella Mine in 1982. The system was introduced to prestrip ahead of dragline excavations and was specified to remove 7.5 million cubic metres per annum in ground somewhat harder than that inwhich bucket wheel excavators are normally operated.This machine has, since 1982, moved more than 77 millionbank cubic metres of material and has been relocated twice. Extensive trials have been undertaken including digging blasted rock.

Jan 1, 1992

By Holliday R, Floyd JM

A laboratory investigation was carried out to determine the distribution of gold between the products of lead-zinc concentrate smelting in the Imperial Smelting Furnace (ISF). Bullion, speiss and slag from the ISF at Cockle Creek were used as the starting materials to evaluate the effect of gold and copper content of products on the distribution of gold between phases under conditions simulating those in the ISF hearth. The ratio of gold in bullion to gold in speiss has a mean value of approximately 1.6 and is independent of the gold content of the bullion. The distribution coefficient of gold between bullion and speiss is dependent on the copper level in speiss and is lowered by increasing copper content in speiss. The ratio of gold in bullion to gold in slag is in the range 25 to 5700 and dependent on the gold content of the bullion. For low gold concentrations in bullion of the order of 1 g/t and a bullion to slag ratio of 1:3 the gold loss to slag is expected to be approx- imately 23%. In all tests the gold in slag remained low, in the range 0.05 to 0.5 ppm provided metal prills were not suspended in Slag.

Jan 1, 1986

By Kavetsky A

In surface mining operations, the ease with which a muckpile may be dug is a dominant factor in mining efficiency. Within broad limits, this is largely dependent on muckpile shape and looseness within a muckpile. Moreover, prediction of grade boundary movement and subsequent dilu- tion is of interest to most open cut mines. Such a predictive tool would enable blast design changes to be made to reduce mixing of certain grade regions. At the very least, a good knowledge of post-blast region bound- aries can reduce layout of the grade boundaries and decrease grade dis- crepancies between pit and plant. The model presented in this paper is able to consider various options for a production blast and predict consequent muckpile shapes and grade boundary movements in a three dimensional manner. The overburden geometry, hole patterns, hole inclination and charge distribution are all explicit model inputs. The model divides the rock mass into blocks and calculates a velocity for each block. Three controlling parameters are used in the model, which are related to the explosive energy per unit length of blast hole, energy attenuation of the rock mass and inter-row delay, respectively. The output of the model is a 3 dimensional muckpile shape (contour or any cross section) and a contour map of grade distribution within the muckpile. The model parameters are site specific, since their values depend on the rock condition and explosive-rock interaction which varies from site to site. In order to "tune" the model to a particular site, parameter values must be found which reproduce an observed muckpile profile shape from a given blast design. This calibration of the model requires at least one surveyed muckpile profile shape from a production blast. The model parameters which best reproduce that shape are found by a pattern search technique, and may then be used to predict the effect of changes in blast design on muckpile profile shape and grade boundary movement.

Jan 1, 1989

By Higuchi K

Intorducing the hypothesis that the cause ,òi spontaneous combustion of coal is depending un the accumulation of heat produced by its oxidation, the authors derived the equation expressing the temperature change in a heap i fine coal. To solve the equation, thermal conductivity, specific heat and rate of heat ,eneration of fine coal (-48 mesh) were measured at various temperatures in the range _'0-65¦C. The equation was solved numerically and the volume of fine coal which would ignite spontaneously was estimated as the function of ambient temperature. Using 170 Kg of fine coal, everal experiments for confirmation were conducted. At the ambient temperatures of 60¦C nd 50¦C, coal began to fire spontaneously brut 00 and 110 hours later respectively. Iii addition to this, the measured t,,rp,i,itures in the coal heap agreed with the ,aLulated ones comparatively well, If more volume of fine coal were used, experi;:ontul ;,eneration of spontaneous combustion from ...,n-, , 1-1 I'd Sill al r..

Jan 1, 1981

By Neill A. O, Worth I, O&apos

The formation of Kalgoorlie Consolidated Gold \lincs 1't% Ltd hati pla,xd all the major the gold producing areas adjacent to the city of Kalgoorlie/Boulder under one management, enabling the development of the 'Super Pit'. This has facilitated the economic optimisation of the resource. Optimisation has been achieved by the timely collection and presentation of data and the use of these data to reduce costs and improve planning procedures.In particular the following issues have been addressed:ò the reduction of the impact of the mining activity on the adjacent urban population centre,ò implementation of safety procedures for mining through underground voids,ò the determination of the optimum bench height and mining method for ore production benches and blast design. This system is fundamentally based on maintaining a high degree of selectivity while achieving a balance of relatively low unit operating costs,ò assessment of the comparable benefits of contractor versus owner operated earth moving equipment, andò the development of effective ore body models, production reconciliation and the long term mine planning procedures to facilitate effective strategic planning.

Jan 1, 1993

By Johnson N. W, Ralston J, Lauder D. W, Smart St C R

The flotation behaviour of the Hilton ore of Mount Isa Mines has been examined in the presence of two collectors (sodium ethyl xanthate (Ex) and sodium diisobutyldithiophosphinate (3418A)) over a range of flotation Eh values and collector additions. Tests were also conducted in the absence of collector to determine the relative contributions of natural and self-induced floatability of the major minerals in the feed. In these tests the influence of metabisulphite on the self-induced floatability of the minerals was also determined. Attention focussed on optimising the selectivity of galena flotation. It is shown that the Hilton ore sample contained lower levels of naturally hydrophobic iron sulphide minerals than are generally contained in the Mount Isa lead-zinc ore. Furthermore, the self-induced floatability of galena was less than that exhibited by the galena in the Mount Isa lead-zinc ore. Sodium metabisulphite (MBS) reduced the self-induced flotation of galena but had no effect on the natural floatability of the iron sulphide minerals.

Jan 1, 1991

By Coombes J, Richards W. L

The objective of this paper is to illustrate, in a practical way, how both geologists and mining engineers can use conditional simulation to add value to their decisions. Inherent assumptions, requirements and essential components of condition

Jan 1, 1998