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By Turnbull A. G

Thermodynamic calculations based on the ideal system NiO - Fe203 - H2(g) - CO(g) - H2O(g) - CO2(g) show that it is not possible to selectively reduce nickel oxide in the presence of hematite because ferronickel is the zero-valent nickel-containing product. The calculations show that temperature, reducing atmosphere composition and oxide to reductant ratio have a marked effect on the nickel content of the ferronickel alloy and the amount of nickel reporting jn the alloy. The general trends based on the calculations correlltte well with experimental observations.

Jan 1, 1980

LAKE MARGARET is situate high up on the West Coast Range of Tasmania, and lies in a roughly triangular valley formed by the ridge of Mount Sedgwick on the south, the ridge formed by Mounts Geikie and Tyndal on the west, amid a ridge connecting Mounts Geikie and Sedgwick on the east. Any description of this hydroelectric installation, however brief, naturally divides itself into the following sections:1. STORAGE BASIN, &c. 2. DAM. 3. PIPE LINES. 4. POWER STATION. 5. TRANSMISSION LINES. 6. SUBSTATION 7. VARIOUS WORKS utilizing the power.The Storage Basin used is the natural lake itself, which has a maximum length of 110 chains, a maximum width of 40 chains, and a mean arelj. of 300 acres. The water-level of the lake, which has been maintained by a natural dam, is 2143 ft. above sea-level. The approximate catchment area at present appropriated is 7 sq. miles, and the rainfall, on the average, about 144 in. per annum. It is possible to increase this catchment area by suitable races, &c. Dam.-The dam constructed is of very small dimensions, and is not a storage dam in the usual sense of the term. The natural storage ot-the lake itself was used by means of a channel cut through the natural dam and thence to the mouth of the lake, the lake level being thus temporarily lowered while the outlet pipes, screens, &c., were placed in position, and the channel was then closed again with a concrete wall in which the pipes and screens are set. This channel was cut partly through rock and partly through sand and conglomerate boulders for a total...

Jan 1, 1915

By D Baas, Y Atasoy

With increased pressure for companies to cut costs during design of new mineral processing plants, overall plant design has changed over the last decade with less design for feed blending and less installed surge capacity. This has changed the operability of new mineral processing plants, where disturbances due to variable ore types have resulted in the evolution of new control techniques. These techniques are necessary to maintain stability and optimise the performance of these new plants. This paper describes the benefit of applying these new control techniques in a new mineral processing plant in Australia utilising RockwellÆs ControlLogix system architecture.

Jan 1, 2008

By Haeussler P, Christie A, Bradley D, Skinner D

Mesothermal gold deposits of southern Alaska and Westland, New Zealand have both formed at the seaward edge of major collisional zones in the Pacific basin. In Alaska, production of large fluid volumes correlates in time with the addition of heat into the lower parts of the accreted terranes in the late stages of collisional orogeny. This heat was critical for driving both the metamorphic reactions that released the large volumes of fluid that carried the gold, and the contemporaneous widespread anatexis and magmatism. In Alaska's Chugach terrane, this heat was produced by subduction of a spreading ridge beneath the North America continental margin in the Eocene. The resulting products were the S-type granites and gold-bearing veins. The similar widespread S-type plutonism and gold veining in Westland's Buller terrane suggest that a similar tectonic event could have triggered ore formation along the southeastern edge of Gondwanaland. Based on the Alaskan model, a Devonian or Early Carboniferous age is favoured for high volume metamorphogenic fluid generation and gold vein formation in Westland.

Jan 1, 1995

This paper considers three aspects of cemented fill practice and research in Mount Isa. Firstly, an account is given of the use of Portland cemented hydraulic fill, considering mainly the role and specifications of the fill used but including û brief description of fill preparation and placement. Data resulting from a Portland cemented hydraulic fill sampling, curing and testing campaign covering about 18 months of operating practice are presented, analysed and discussed. These yield information indicating the mode of operation of a fully-automated fill preparation station, as well as a means of comparing field and laboratory strength results. A technique with potential for use as a fill quality control without actual strength testing is also described. Results of a fill research program conducted by the author in Mount Isa since early 1968 are presented, involving both Portland cemented hydraulic fill and alternative, cheaper, additives for cementing hydraulic fill.

Jan 1, 1971

By Wu Y, Qu Q

The Central Coal Mining Research Institute has developed the MAE acoustic emission monitoring system, the BD4-1 portable acoustic emission monitor and the MRB rock burst monitoring system. In the MAE system there is an IBM-PLAT, a receiver and 16 channels and the investigating range is 100 m. The main functions are detecting acoustic events from the working faces, periodically making statistics, prints, displays and storing of the results, and performing the off-line process such as drawing the curves of acoustic activity. The BD4-1 instrument has four channels, it works for more than 24 hours continuously, and keeps the data for more than 30 days after power tum-off. The BD4-1 is suited to the monitoring for a long or a short time as a fixed point where the system is invalid, especially to the monitoring of the acoustic activity promoted by the blasting. There is an IBM-PC/AT, a receiver and 16 channels spread 10 km in the system MRB. The system could on-line collect microseismic events throughout the whole mine, calculate the source location and the energy, and off-line draw the seismic activity draft of time-based or distribution in space. In practice, the forecasting is successful by using the acoustic emission and microseismic monitoring system and the portable instrument.

Jan 1, 1991

By C M. Côte, P Bolz, R Chrystal

The design of final landforms is an integral part of mine closure plans in Queensland and aims to ensure the rehabilitated land is safe, stable and non-polluting. Landform stability in this context is commonly assessed using Landscape Evolutions Models (LEM) which are physical models simulating sediment erosion and deposition around individual landforms over long timespans (up to thousands of years). The most used LEM for assessment of rehabilitated landforms in Queensland is SIBERIA (Willgoose, Bras and Rodriguez-Iturbe, 1991; Tucker and Hancock, 2010). SIBERIA models are complex, require very detailed input data and simulate erosion and deposition over time frames that extend decades beyond closure. They are not suitable to assess erosion risks during the operational phase of a mine and to support the development of erosion and sediment control plans. Other types of erosion models, such as the Revised Universal Soil Loss Equation (RUSLE, Wischmeier and Smith, 1978) or Water Erosion Prediction Project (WEPP, Nearing et al, 1989) calculate soil loss on a monthly or yearly basis and are much better suited to erosion management during the operational phase. They are simpler to implement and can support the design of control measures. For instance, designing a sediment basin requires quantification of sediment loads, which can be produced by these models. In Queensland, the legislation around sediment and erosion control for open cut mines is currently tightening. Soil erosion remains a major concern due to potential impacts on the receiving environment. It requires management during operation and for closure consideration alike and it is critical that erosion and sediment control plans are developed with the most appropriate tools. Globally, RUSLE is the most widely used soil loss model (Borrelli et al, 2021). This is because it is an empirical model with relatively simple input requirements: biophysical data such as soil properties, vegetation cover, topography and rainfall variability, which can be directly measured or derived from regional or national databases and/or spatial data sets that are available in most parts of the world. The second most used model is WEPP (Borrelli et al, 2021) but compared to RUSLE, there is a large drop in the frequency of its use. This is because WEPP is physically-based and has more complex data requirements. WEPP integrates hydrology, hydraulics, erosion mechanics and land cover to predict soil erosion and sediment transport on hill slope profiles and small watersheds (Stolpe, 2005). It requires some biophysical parameters in formats different from those of RUSLE, as well as detailed hydrologic and catchment data. Nevertheless, it has been used in landform design for mines across Australia to determine final landform stability (eg Howard and Roddy, 2012; Costin, 2020). In this study, we assess which tool would be the most appropriate to support development of erosion and sediment control plans from operation to closure. We use RUSLE and WEPP to predict soil loss from a mine site, compare the results from both models and outline the advantages of each method.

Aug 2, 2023

By I M. Howard

With the bell-less top (BLT) charging system replacing the centuries old double bell charging method, the furnace efficiency has been greatly improved together with considerable reduction in the furnace down time and operational problems. But still there are many draw-backs which need further attention to achieve better efficiency and operational effectiveness. The performance and operational problems of the BLTs have been highlighted and possible solutions to overcome some of the major problems are discussed.

Jan 1, 1999

Plant based on the New Jersey refluxing process was installed at the Cockle Creek Works of Sulphide Corporation Pty. Ltd. to refine portion of the zinc output from the Imperial Smelting furnace.Refining of impure zinc is effected by distillation in two stages in vertical columns comprising a series of superimposed silicon carbide trays designed such that ascending zinc vapours and descending liquid metal are in intimate contact. In the first stage, portion of the zinc and its cadmium content are distilled from impure feed metal, condensed, and while still molten, fed to the second column in which zinc is boiled under controlled refluxing conditions to remove the cadmium content.The resultant zinc has a purity in excess of 99·995 per cent zinc.The availability of refined zinc has made possible the production of a number of zinc alloys for marketing in addition to the basic grades of zinc.

Jan 1, 1970

A numerical method for discriminating between replacement and sedimentary processes is applied to a folded stratiform sulphide occurrence. It is shown that numerical treatment of chemical analyses from a single diamond drill hole allowed a rapid assignment of the ore to the syngenetic sedimentary class and thereby enabled a revision of the evaluation program concerned with consequent reduction in costs.

Jan 1, 1973

By E Werner, J J. Donovan, A J. Morris

Coal mining in the Pittsburgh coal seam, in the eastern United States, began in the late-1700s. Since that time numerous mining technologies have been used throughout the basin. Environmental concerns, particularly mine discharge quality, have only been considered since the early-1970s. During the last 20 years, many of the larger underground mines have closed and are now either flooding or already flooded. In order to understand the consequences and potential future effects of this flooding, mine mapping of the basin has been compiled utilising a geographic information system (GIS) with an emphasis on locating barrier pillars between mines. Mine flooding has been monitored at numerous sites utilising pressure transducers and data loggers. These data have been combined with historical data from mining companies and structure contour maps to yield chronological flooding maps of the basin from 1980 to present. Utilising these maps and the indicated flooding rates, future discharge locations have been identified along with estimates of when these discharges are likely to occur. Related work has identified barrier pillar hydraulic conductivities and vertical infiltration rates as a function of overburden thickness. All of this information has been integrated into a groundwater flow model that simulates mine flooding. This model is useful in defining mine to mine interactions as the various mines fill with water, and the testing of various flooding scenarios. The model will be used in evaluating mine discharge rates and evaluating the options for regional mine drainage treatment.

Jan 1, 2003

By J D. St George

In this paper a laboratory investigation into the effect of confining stress, water content and gas desorption on coal permeability is presented. Of major significance is the effect of coal permeability on outburst occurrence and methane production, which is influenced by changes in stress. Test results indicated that the shrinkage of the coal matrix associated with desorption is greater than the coal matrix compressibility which will cause a reduction in the effective stress, hence increasing coal permeability.

Jan 1, 1998

By Hedley TP

Success for underground coal mine operators in the 1990's and beyond will be dependent upon better understanding of the dynamics of their operating environment, and extension of emerging technologies to reach new levels of output and productivity. The Collieries Division of B.H.P. Steel International Group clearly identifies with the concept of business/product life cycles - and the need to adopt strategies that can drive the business successfully into the future. Three main thrusts within BHP Collieries Division relate to: 1) Detailed assessment of current mines to determine: a) The real output potential of the current facilities. b) What factors now inhibit the full potential from being realised. c) Opportunities that exist to enhance overall mine performance. 2) Based upon the findings of these studies, putting into place cost effective strategies and systems for the ongoing "tuning" of the mine. 3) of new/improved technology primarily in areas of: a) Coal cutting and underground coal clearance. b) Controlling the overall mine gas Regime.

Jan 1, 1987

By N E. Whitehead

An application to mine an ilmenite-rich sand deposit in Westland led to public concern about potential radioactive hazards should the ore be further processed to recover zircon or monazite. A review recommended that any material involved in the heavy mineral sand industry containing more than 0.05% thorium, uranium or their mixture should be considered a radioactive substance and, for mining purposes, a notifiable product. Safeguards for those occupationally exposed would operate via the Radiation Protection Regulations. The major safety requirement would be the minimisation of dust in certain operations.

Jan 1, 1993

By K H. Esbensen

The Theory of Sampling (TOS) has made remarkable strides and has witnessed a suite of achievements over its ~65-year history; especially in the last 15 years, since organised work began for the erstwhile fragmented sampling community (2003). Theory and practice have been very well exposed and disseminated, as witnessed in the successful series of the World Conference on Sampling and Blending (WCSB) events and other dedicated sampling and mining conferences in Australia and South Africa. At this WCSB8 occasion we fittingly devote a section of our conference to celebrate the life and monumental achievement of Pierre Gy, the originator of the Theory of Sampling; a special issue of TOS Forum was recently published to the same purpose. But TOS is most emphatically not a finished work.Here I try to look into the future with a personal view: TOS – what’s next? Commensurate with this objective there is offered some out-of-the-box thinking. The purpose is to try to zoom in on probable additional future aspects of TOS and its application compared to the first 15 years of our common journey. There are bound to be lacunae here-and-there across the vast application horizon delineated, which is as it should be, as this lecture is meant to initiate a broad(er) debate – and readers may agree with all, parts, or none of the topics presented. All is well that furthers this debate.CITATION:Esbensen, K H, 2017. Theory of Sampling – what’s next?, in Proceedings Eighth World Conference on Sampling and Blending , pp 29–38 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The treatment of slimes has of late years been the chief difficulty in connection with cyanide work, in which much time and money has been spent in endeavouring to find a practical solution of this problem.The processes at present in use are:-1. Filter pressing, as practised in Western Australia.2. Decantation, as practised in South Africa.Filter pressing after apitation affords a ready and efficient means of separating the gold bearing solution from the slimes and admits a perfect washing thus ensuring a high extraction but the very high working costs forbids its application except on high grade material, the chief items being the necessary large amount of labour, compressed air, and general upkeep, none of which can be materially reduced. The decantation method has the ad vantage of low working cost but on the other hand the low extraction obtained, due to imperfect washing, the length of time occupied in' the treatment, and the enormous bulk of solutions to be handled, are serious disadvantages.In either process it is absolutely necessary to obtain a perfectly clean solution before starting the gold precipitation by zinc, which is a source of much trouble. Also the high first cost of installing either plant is such that they can only be adopted on mines with very large working capital.

Jan 1, 1903

Petroleum exploration in the Australian arid zone has been proceeding at an ever-increasing pace, subject to financial fluctuations, since the 1960's. The impacts of petroleum exploration in the arid zone are less than they would be for corresponding operations in. e.g. a forest area: in this context, Australia is fortunate in that its major petroleum producing (and prospective) , basins are offshore or in the arid zone. In addition. the other major sources of impact in the Austrlian arid zone, namely pastoralism, tourism, and rabbits, tend to be concentrated around areas of particular conservation significance, whereas petroleum exploration is not. Despite this, the cumulative impacts of exploration are sufficient to have caused concern to government regulatory authorities and some sectors of the general public. Exploration is now subject to a range of environmental constraints with various degrees of legal enforceability. To enable exploration to continue without public opposition, the industry, and government agencies charged with regulating or supervising it, must demonstrate that the net benefits of exploration exceed net costs, including environmental costs. One particularly simple and cost-effective technique for increasing the net benefit/cost ratio of exploration is to reduce the net environmental costs by minimising and mitigating the impacts, both primary and secondary, of seismic acqisition. This is best achieved by a combination of preventive and restorative techniques: careful line positioning and low-impact (or zero) line clearance, coupled with simple rehabilitation of bladed lines. Line clearance without bulldozer blading - e.g. by rolling or simply pegging and trafficking, perhaps with tracked rather than rubber-tyred vibroseis - is one promising approach currently coming into use. Rehabilitation by grading soil banks ("windrows") back on to bladed tracks, though not yet in widespread use, has proved very successful in the limited areas where it has been applied to date.

Jan 1, 1987

Mining regulatory authorities worldwide mandate frequent inspection of winder ropes used in shaft-equipped underground mines and ski lifts. Visual inspections are effective in identifying and assessing the type and severity of damage found in the exterior of the rope. In addition, electromagnetic or permanent magnet-based methods are used to identify broken wires, corrosion damage and other anomalies that occur anywhere within the core of wire ropes made of steel, which is a ferromagnetic material. The magnetic methods yield the loss of metallic area due to wire breaks and other damage in the ropeÆs section as well as local flaws that give rise to discontinuities in the magnetic field. The quantitative measurement of the loss of metallic area is indirectly related to the loss of breaking strength that is commonly used as a rope discard criterion. The ropes used in a mine winder in the Goldfields of Western Australia are inspected using Meraster 120B permanent magnet-based rope tester and their condition is assessed against published discard criteria.

Jan 1, 2003

The offshore Maui gas/condensate field was discovered by Shell BP and Todd on Services Limited in 1969. Subsequent appraisal drilling and negotiations with the Government led to a development agreement, æThe Maui White Paper' being concluded in 1973. Part of this agreement provided for the Government to take a 50 per cent shareholding in the field. The field is comprised of a double domed anticlinal structure containing two gas reservoirs at depths ranging from 2700 - 3000 m. Water depth is 110 m. The development plan called for two standalone steel platforms to be installed sequentially over a period of some years depending on gas demand. The first platform (MPA) was put in place in 1976 but difficulties were experienced with piling and drilling of the 12 (later increased to 14) wells did not start until 1978. First gas was piped ashore late in 1979.

Jan 1, 1994

Total mechanisation in the Western district of New South Wales is quite a recent addition to productive methods in that State, for it was only in 1940 that the first colliery was equipped for this method of winning coal. Now almost all mines either are totally mechanised or are planning to get their coal by these means.This marked change in recent years is explained by the salient features of the industry's history. Collieries in New South Wales had generally been subjected to low selling prices forced on them by over-production and severe competition. Little money was available out of profits to purchase machinery, and returns on capital were so poor that inducement to invest money in the industry was nonexistent.The second world war brought price fixing at the already low prices. It was not until the post-war period that there has been any inducement to mechanise.Much credit for mechanisation can be given to the Joint Coal Board, a government body formed in 1948. Pursuing a broad plan for the rejuvenation of the industry, this Board, purchased large quantities of machinery for use in, mines under hire-purchase agreement. These agreements encouraged machine mining, and this fact, together with the ensuing production economies, has improved the financial position of the industry.The Board has also been instrumental in the granting of increases in the fixed price of coal, so that the industry has been given an even greater boost in the direction of mechanisation.

Jan 1, 1954