Search Documents

By G R. Hancock, M J. Saynor, J B. C Lowry, K G. Evans, M Narayan

Tools such as landform evolution models (LEMs) provide a means of predicting how a landform may evolve over extended periods of time. Here, we utilise the CAESAR-Lisflood LEM to assess a proposed rehabilitated landform of the Ranger Uranium Mine in the Northern Territory of Australia (Figure 1). The environmental requirements for the closure of the mine state that the final landform must be able to physically isolate tailings material from the environment for a period of at least 10,000 years (Australian Government, 1999). However, uncertainty exists as to the reliability of model predictions representing thousands of years.In this study, we use model predictions from an undisturbed pre-mine landform to calibrate the parameters used in model simulations of a post-mining rehabilitated landform over a simulated period of 1,000 years. Specifically, we vary environmental conditions such as rainfall, presence/absence of vegetation and surface particle size characteristics in a series of model simulations to determine their impact on the respective landforms, to revise model input parameters as required. A simulated period of 1,000 years was used as it represents a period in which long term landform evolution patterns and trends may be established and identified. CITATION:Lowry, J B C, Narayan, M, Evans, K G, Saynor, M J and Hancock, G R, 2018. Using an undisturbed landform to calibrate long-term predictions of the evolution of a rehabilitated landform, in Proceedings Life-of-Mine 2018, pp 133–137 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By C Balci, D Tumac, A Sheterpour-Mamaghani, E Dogan, A Kocbay, T Erdogan, A Gumus, H Copur, E Altintas

Excavation of vertical and/or inclined shafts in the underground structures requiring careful design and planning. Raise Boring Machines (RBMs) are commonly used for excavation of shafts for different purposes such as ventilation, orepass, and human-material transportation. Proper selection and accurate performance prediction of RBMs are two main parameters affecting the cost estimation and planning/scheduling. Indentation test is one of the most preferred methods that can be used to predict advance rate of RBMs. This study aims at suggestion of new prediction model for instantaneous penetration rate of RBMs based on indentation tests. Different rock (core) samples (with different geological origins) are obtained from the raise boring application projects in Turkey; then, the indentation tests are carried out on them by using a real-life insert (button), which is used in reamerhead cutters investigated in this study. Finally, the statistical relationships between the field performance and the indentation indices are investigated. The study indicates that the brittleness index (the ratio of maximum applied force to corresponding penetration) can be used to predict instantaneous penetration rate of RBMs used in the vertical raise bored shafts excavating rocks having uniaxial compressive strength lower than 100 MPa.

Nov 29, 2022

By J Butler, N Patel, S Narendranathan, S Rastogi

The Yallourn Mine (YM) commenced mining of brown coal in the 1920s under operation by the State Electricity Commission of Victoria (SECV), prior to it becoming privatised in 1996. The present owners of the YM, Energy Australia Yallourn (EAY), acquired the site in 2000 and intend to continue operations until scheduled closure in 2028. Brown coal extracted from the YM is fed into the Yallourn Power Station which supplies approximately 22 per cent of Victoria’s electricity. Water within the YM is collected and stored in the Township Field Fire Service Pond. Water levels within the Fire Service Pond (FSP) may fluctuate considerably depending on the requirement for storage at the site. With due consideration to the stability performance of mine batters adjoining the FSP, the authors performed slope stability assessments to evaluate the risk and consequence of batter instability during the potential pond filling as it approaches the ‘critical pool’. The critical pond is defined as the level at which the driving forces (destabilising forces) are at their greatest and the resisting forces (lake forces, friction) are at their lowest. This assessment was undertaken using the Mine Geotechnical Risk Index (MGRI) approach.

Aug 2, 2023

This work was instituted to investigate the microscopic structure of brown coals by means of microtome sections cut from them. It was found to be essential to impregnate the coal with some material prior to cutting, because of its powdery and crumbly nature. Of a number of impregnating materials tried, e.g., glycerine gum, gelatine, by far the most satisfactory was paraffin wax. Samples of brown coals for section cutting must be moist. When obtained, they should be put immediately into air-tight tins, and, if they are not to be used for some time, it is desirable to keep them under water containing a small amount of formalin. If the sample is allowed to dry in air, it becomes too hard to be cut. It cannot be softened again even by prolonged soaking in water.PREPARATION OF COALSmall rectangular, blocks were cut from the sample with a chisel and a strong scalpel. The largest block prepared was 3·2 x 2·5 x 0·6 cm. The faces of the block from which sections were to be cut were approximately levelled before treatment. The block was then painted carefully on all sides with two coats of warm aqueous agar, approximately 2 %. This prevented crumbling and breakage of the block during treatment. When the agar was set, the block was placed in water, and all the air removed with a vacuum pump. The water was replaced first by alcohol, then by chloroform, by the usual step transference of a series of liquids, in each of which the block was placed for 24 hours: Ethanol %, 10, 20, 30, 50, 70, 85, 95, 100 (three changes); Ethanol-chloroform, 3: 1, 1: 1, 1 : 3, chloroform pure (three changes) '. The blocks were then embedded in paraffin of melting point 56-58°C. Fresh...

Jan 1, 1947

Increasing use has been made of engineer ing geology and hydrogeology in the development of the infrastructure for mining projects. The Geological Survey of the Department of Mines, the Department of Main Roads, the Irrigation and Water Supply Commission and private consulting organisations and mining companies, employ spec- ialist staff to carry out engineering geological and/or hydrogeological investigations. Such in- vestigations have been of assistance in recent mining developments in northern Queensland, in- cluding those in the Cloncurry - Mount lsa, Weipa, Greenvale and northern Borten Basin areas.

Jan 1, 1974

Recovery of tin and copper from concen trates containing cassiterite, stannite and chalcopyrite was studied in laboratory-scale tests designed to simulate continuous operation of the matte fuming process in which tin is recovered as SnS fume while copper accumulates in the matte. Charges made up of 300g of mixtures of the concentrate and siliceous flux were added at a uniform rate in pelletized form to crucibles containing 300g of matte and 50g of slag (both of which were recovered from previous tests), while blowing through the matte with air or oxygen-nitrogen mixtures at a rate of 3 to 5 1/min. Accurate material balances enabled the effects of process operating conditions on tin recovery and sulfur utilization to be deter- mined. When operated correctly, the matte fuming process gave tin recoveries exceeding 90 percent in spite of wide variations in the copper content of the matte and in the operat- ing conditions. Deterioration of tin recovery was associated with undersaturation of the slag with respect to silica, and with high partial pressure of sulfur dioxide (greater than approx- imately 0.2) brought about by oxygen enrichment of the blowing air. The utilization of sulfur varied widely in low grade mattes. Copper in excess of approx- imately 10% promoted formation of SO2 by the commonly accepted reaction: FeS + 1-120 2= FeO + S02 while in copper-free and lower grade mattes a substantial fraction of the oxygen was consumed in the alternative reaction FeS + i 02 = FeO + z S2.

Jan 1, 1980

The problems of the as-built water supply system are discussed. Recent modifications to the collection dams and the water cleaning station using wedge wire screens to resolve these problems are outlined.

Jan 1, 1978

By C Grobler, M Recklies, G Jiang, I Taylor, M Morgan, G MacDonald, L Smith

The resource estimation of lateritic deposits, such as Aurukun, presents specific issues related to the lateral changes in thickness and elevation of the various horizontal layers (or zones) within the deposit where the x and y dimensions are orders of magnitude greater than the z dimension. The objective was to develop a three-dimensional (3D) block model that retained the vertical and lateral variation inherent in deposits of this type to allow full optimisation of the production plan without prior selection of an economic portion (enriched bauxite layers) of the profile at the resource estimation stage. The Aurukun bauxite deposit is held by Chalco Australia Pty Ltd (Chalco) and forms part of the world-class Weipa bauxite province, Cape York Peninsula, Queensland, Australia. The bauxite is predominantly pisolitic with an upper boehmite-rich zone and lower gibbsite-rich zone. The bauxite consists of both in situ and reworked domains, is overlain by a thin soil horizon and has kaolinite clay as a transitional base. A portable infrared mineral analyser (PIMA) was utilised on site, in addition to elemental assay, on each drill sample to determine the mineralogy, in particular levels of boehmite, gibbsite, kaolinite and reactive silica. As part of the scope of work, a field program was undertaken using large diameter Boart Longyear sonic drilling to acquire detailed density measurements across the deposit to allow compliance with Joint Ore Reserves Committee (JORC) reporting requirements. Interpretation of the stratigraphy was conducted on a hole by hole basis with definition of the zone layering based on stratigraphy, geochemistry and mineralogy. The zone boundaries were then modelled as 3D surfaces and used to constrain a block model. The block model estimation used the ordinary kriging method, with the estimation done in unfolded space and then refolded, therefore maintaining the zones irrespective of thickness or orientation. The unfolding process converts the real-world positions for both blocks and informing samples to a scaled position relative to the roof and floor of each zone. Analysis of the data and variography were also undertaken in unfolded space. The x and y dimensions are unchanged, but the z dimension is a relative position. The effect of the unfolding and limits on number of samples per hole is to æpushÆ the informing sample search sideways but within the stratification, rather than vertically. This honours the strong vertical zonation within the bauxite profile. The JORC Code requires that the stated resource must have æreasonable prospects for economic extractionÆ. This is a qualitative rather than quantitative definition. A number of selection criteria to define a resource roof and floor were developed in consultation with the project engineers and owners to meet these criteria. The vertical selection of material to include in the resource highlights the variation in the development (and destruction) of the bauxite profile from area to area within the deposit.

Jan 1, 2009

By Muir DM, Tsuchida N, Dalton R

The adsorption or loading of anions onto extruded based peat activated charcoal has been studied by potential measurements in a flow through cell. Loading rates are in the order F-

Jan 1, 1984

Australian continental crust has accreted and consolidated by thirds: 1/3 during Archean time, 1/3 during Early to mid- Proterozoic time, and 1/3 during latest Precambrian to mostly Paleozoic time. The progression of orogenic systems and the crustal consolidations they represent seem not fundamentally different in basic orogenic processes from better known Mesozoic-Cenozoic examples in that accretionary, continental margin, collisional, and intraplate intracratonic inverted and/or reactivated systems are all recognizable in the tectonic evolution of Australia.

Jan 1, 1995

By Beck RW, Booth GW

Differences in the gold contents of sub-sample duplicates, derived from a single bulk sample are a function of analytical and random error, inhomogeneity within the bulk and natural variations in the distribution of particluate gold. By minimising bulk sample inhomogeneity and determining analytical precision, the residual natural variation may be modelled statistically to give an estimate of Bold particle sizes.

Jan 1, 1989

By Taylor MN

The influx of an industrial environment into or adjacent to the indigenous society has in the past frequently caused the breakdown of traditional be- haviour and culture, and the generation of social and psychological impacts on the local population. Successful programmes developed by government agencies and private industry have been implemented in many areas to maintain the cultural environment and still afford the needs for industrial development. The ultimate goal of such programmes should be directed toward eventual operation and management of the established industry by the local population.

Jan 1, 1978

By Smith S. F, Terezopoulos N. G

This paper discusses experimental results of physical scale models employed to study the stability of a pillar between rectangular roadways. A programme of laboratory investigations utilising a bi-axial test rig has been undertaken to examine the influence of various stressfields on the stability of pillars between mine roadways. The effect of pillar height/width ratio on the overall stability is studied. Observations of failure characteristics in and around pillars are discussed especially in relation to the various stressfields applied to the models.

Jan 1, 1992

The Mine Safety and Inspection Act, 1994 of Western Australia recognises the importance of ground control in underground mining. The recent safety performance of underground mining is summarised in terms of the most common causes of injury and fatal accidents. A review of current ground control practices is presented and the concepts of local and large-scale ground control are introduced. The need for a more systematic approach to ground control is considered to be directly related to requirement to improve safety performance. The new regulations will require that certain geotechnical issues be addressed during the life of a mine. To comply with the regulations it is suggested that a ground control management plan be developed for each mine. The geotechnical issues associated with the ground control management plan are reviewed and hazard recognition aspects discussed.

Jan 1, 1995

By A Dunne, R Kruger, H Coleman, P G. Laurens

External and internal challenges in mining are increasing the difficulty and complexity of operating mines. The external mining environment has a big impact on mining operations and is driving the focus on safety, sustainable mining, green issues, profitability and productivity. There is a very high emphasis on ‘reducing cost to improve’, lower mining and beneficiation costs by eliminating waste/inefficiencies (reduce people, use less consumables, multiskilling, etc). The internal mining environment is getting tougher to operate in, with the deposits being more difficult to mine, more difficult to manage due to external pressure along with issues associated with maintaining quality, etc.Technological and environmental developments too numerous to mention, mean that cost control models, reduction in human resource numbers, as well as other drastic measures to curtail expenditure and increase profitability have become part of everyday business. The capability to manage the mining environment in a systemic manner has been lacking and this increases the pressure for performance on those individuals operating and managing mines.Working smarter has become crucial to ensure that businesses optimise the use of their resources, become more safety conscious, more productive and remain cost-effective, while recognising the importance of sustainable mining now and in the future. The logic of determining and managing to the capability of the mining value chain will be examined and the underlying assumptions or beliefs guiding behaviour and decision-making will be highlighted.In order to identify the obstacles in the mining value chain that hinder achievement of its full potential, the following questions have to be asked:What are the factors that influence the performance of a mining value chain?What is the design capacity of the mine?How can the inherent flow and value capacity of a mine be determined?What types of solutions will allow a mine to operate at its inherent flow and value capacity?This article will discuss the way we plan, measure, assess and manage the mine value chain, by addressing the following factors:balanced capacity versus flow and value capacity designthe use of averagingoptimising individual components in a value chain versus optimising the whole value chain.Optimising flow and value through the mining value chain is one of the three pillars of Mineral Resource Throughput Management (MR™). MR™ is an entrenched and academically supported philosophy that has been successfully applied in the past decade in various mines throughout the world by EXXPLEO, a mining and beneficiation consulting company. EXXPLEO has partnered with HCL (a global IT company) to embed the MR™ philosophy, methodology and toolsets into a formal software product called Synchronised Digital Mining (SDM). The SDM system will provide mining companies with a sustainable platform to effectively apply the MR™ principles and toolsets effectively across all operations targeting increased productivity, efficiency and profitability without having to train operations and management staff into expert MR™ practitioners to successfully achieve the desired results.CITATION:Dunne, A, Laurens, P G, Kruger, R and Coleman, H, 2015. Optimising flow in the mining value chain, in Proceedings Iron Ore 2015, pp 437–442 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Denby B, Hollands R. Schofield D

Surface mines are in operation worldwide, the vast majority employ large haul trucks for the transfer of material both to the outside world and around the site. The sheer size of these trucks and the operating conditions means there is a high

Jan 1, 1998

Environmental considerations were key factors in the design of the Ranger Uranium Mines treatment plant. The mine is located adjacent to the Kakadu National Park and has an average rainfall of 1.6m per annum. Initially, no contaminated water or liquid effluents are to be released from the project area and thus water management is a key design and operating fact. Particulate and gas emission criteria influenced design as did occupational hygiene factors (dust, radon, housekeeping, maintenance access). Equipment selection and engineering standards were conservative and resulted in the plant attaining design performance in less than three months from the date of commissioning. A number of mechanical and operational problems were experienced and are discussed in the paper, however none of these problems have had a significant effect on production.

Jan 1, 1984

Several new techniques. which may be applied with advantage to the search for uranium are described. Scintillation type gamma spectrometers are now available for airborne', ground and borehole use. These can distinguish in a broad way between anomalies due to uranium, thorium and potassium. Gamma spectrometers based on semiconductor detectors now under development should be capable of much greater resolution. These should also make possible rapid, accurate and cheap radiometric analyses of samples containing uranium and/or thorium, whether in radioactive equilibrium or not. Another valuable prospecting aid, particularly in areas of tropical leaching, is systematic sampling of soil for radon content. Equip- ment for this purpose is currently available and it will be possible to extend the method when development of an alpha probe suitable for use in deeper holes is completed. Variations in the concentration of certain trace elements'in soil (e.g. mercury) also offer promise in the search for mineralized zones which may contain economic eon¦- centrations of uranium.

Jan 1, 1968

By Eupene GS, Cheong GE

Operations at the Mount Bonnie gold/silver project are described. The project is based on the gossan of a stratiform and stratabound polymetallic sulphide deposit. The gossan contains approx- imately 100 000 tonne of ore grading 8g/tonne Au and 230g/tonne Ag. This is mined in an open cut, and transported to a stockpile area lkm away, from which it is fed to the treat- ment plant. The ore is crushed through two stages and fed to a fine ore storage shed, from which it is reclaimed, milled and cyanide leached in draft tube agitators. The pulp is filtered using a horizontal belt filter to recover a pregnant solution. Silver sulphide is precipitated using sodium sulphide solution, and collected as a mixed sulphide/precoat concentrate on a drum filter. The solution is then passed through carbon columns where the gold is adsorbed and is subsequently recovered by methanol desorption using a process developed by Micron Research, and electrowinning. Modifications to the treatment plant circuit based on operational experience are Described.

Jan 1, 1984

By Nilsson C

Man has always been and will always be part of his environment, in ,a good, bad or indifferent manner. Until quite recently, this environment has been the atmospheric boundary layer above the land masses, and to a limited extent the air-sea interface of the oceans. Since the days when he lived in caves, he has built up a wealth of observations on these two environments,-with ever-increasing scientific precision which unfortunately until quite recently was completely insufficient for modern capabilities of data analysis. Consequently, in a sense, he has left in his wake thousands of years of missed, opportunities for making exact observations and increasing his understanding. The data of the past are lost and he has to be satisfied with what he can assemble from now on when his environ- ment, largely as a result of his actions, is exhibiting more and more rapid variations in time; in other words, time series of observations of phenomena are required, the length of which is critical for most purposes of analysis.

Jan 1, 1970