Search Documents

The subject of steel wire ropes covers such a wide range of points that it would be impossible to deal with it fully in one paper, and in view of the apparent scarcity of published information on the subject it is proposed in this paper to deal with those items which should give the mining engineer a better understanding of the basic factors which affect the design.selection, and use of ropes. The matter will be considered under the following headings:-1. Brief history of steel wire rope-making.2. Rope-making terms.3. Wire rope materials.4. Characteristics affecting economy, operating life, and serviceability of a rope.5. Properties of construction of rope, and stresses met with in wire ropes.6. Drum and sheave sizes and sheave bearing pressures.7. Storage, handling, and maintenance of ropes in service.8. Common factors affecting rope life, particularly winding and haulage ropes.9. Inspection of ropes.GENERALWire rope, which was invented for, and first applied to mine winding, has become an indispensable aUXiliary throughout the whole field of mining, be it for underground, open cut, or dredge work, as well as the requirements of transport and treatment of ores.Though wire ropes appear simple collections of wire and fibre, the demands made upon them are many, and the stresses and abuses to which they are exposed in service are varying, and often of serious dimensions.The exposition of these stresses and abuses, particularly dynamic stressing, corrosion, etc., all of which seriously affect the safety and economical life of the ropes, is often enough to frighten most practising mine staffs, who are aware that before the requirements of economic operation stands the still more important question of safety in mining.

Jan 1, 1947

By W Stange

Assessing the risks in a mining project is a key aspect of project evaluation. This is an exacting and demanding task because of the complexity due to the need to deal with uncertainty over long time periods. The way risks are assessed and managed is critical to the long-term success of the projects and the business. Discounted cash flow (DCF) analysis is commonly used for project and risk evaluation. A discount rate is selected that accounts for uncertainties in the cash flows. However, it is difficult to determine an appropriate discount rate due to the large number of factors that need to be considered and the complex relationships between risk sources. Using a proven framework, ævalue at riskÆ (VaR), this paper proposes to rigorously model and quantify ærisk at sourceÆ. The approach was first employed to assess financial market risks and is now widely used in the banking sector for risk assessment. In project evaluation, all risk sources are identified and estimated separately to ensure the overall project risk is quantified accurately. A bottom-up approach has been proposed. Estimates are first carried out for risk factors at the bottom of the project structure. The assessment is then applied at increasingly higher levels until the overall project risk is estimated. Value at risk is a versatile methodology and can be used in a local or integrated manner. The final value is objective and the calculation steps can be easily justified and followed. Four case studies have been included to illustrate how the proposed approach can assist management in decision-making.

Jan 1, 2009

The paper gives details of the reasons why attention was directed towards the modification of flotation cells. The cell volume and impeller speeds were reduced, and it is estimated that the power consumption for lead and zinc flotation will be reduced by about 2·8 kWh per ton of ore treated, and that substantial savings will be made in maintenance costs. The metallurgical efficien.cy of the operation has been maintained and attention is now being directed towards the improvement of grades of concentrates and recoveries of metals.INTRODUCTIONIt was on 1st August, 1934, that the first Denver No. 21 flotation cells were operated in the treatment plant of The Zinc Corporation Limited, in a pilot Nant which had been installed to determine the economics of all-flotation as against the then existing gravity and flotation practice.The ore being mined at that time came from the lead lode which consists of a granular mixture of galena, marmatite, chalcopyrite, tetrahedrite, pyrrhotite, pyrite and lollingite with a gangue association of calcite, quartz, bustamite, rhodonite, manganhedenbergite, garnet, fluorite, manganocalcite and apatite. The silver content of the ore occurs in three minerals-tetrahedrite, dyscrasite and pyrargyrite, the last two mentioned occurring in microscopic association only.A parallel lode, known as the zinc lode, was well developed at that time. The common lead lode gangue minerals-calcite, rhodonite, bustamite-were rare in the underground exposures of the zinc lode. No metallurgical work was done on this ore during the pilot plant operations although since then both lead and zinc lode ore have been treated.Early in 1936 plans were made for the complete re-organization of the mine operations, and in view of the metal-

Jan 1, 1956

A brief descri;tioki is given of nuclear power reactors and their fuels. These fuels are made from a variety of uranium compounds such as uranium dioxide, and uranium carbide as well as uranium metal and its alloys. The various processes used to produce some of these compounds from yellow cake are outlined. Using the natural uranium, heavy water reactor by way of illustration, fabrication of fuel elements is dis- cussed and the characteristics of U02 powder required for this partic- ular fabrication are indicated. The flowsheets and equipment presently in use overseas for production of this type of U02 powder are described. Possible areas where improvements might be made to this conventional process are enumerated and some details are then given of the programme of work which has commenced at the A.A.E.C. Research Establishment to gain experience in the general field of nuclear grade UO20

Jan 1, 1968

The South Comet mine is an underground silver-lead-zinc mine located on the West Coast of Tasmania with an annual production in the order of 35 000 tonne per year. All ore mined is shipped to the Rosebery mill by road, a distance of 17 km.

Jan 1, 1993

An image analysis system has been built which automatically digitizes camera input of rock fragments, analyses the digitised data to determine the sizes and shapes of the rock fragments, and outputs the analysed data to a printer in the form of a histogram or a scatter chart. The high speed of such a system allows for direct collection of data from material thrown into the air by blasting, material travelling on a conveyor belt, and material free-falling on to a stock-pile or into or out of a rock-crusher. Data on the blasted, un-crushed material provides information on changes in the lithology and structure of the rock face as it is quarried or mined: flatter fragments may represent approach to a brittle, unstable shear zone, or a change from sandstone to shale; so that the informa- tion reflects the effect on the sizes and shapes of the fragments by the blasting process and/or by the rock structure. The size and shape distributions of rock fragments produced during blasting and during processing may now be continuously monitored. Such detailed analysis of the results of fragmentation is labour-intensive and expensive when the size and shape distributions are obtained manually, but is cheap and efficient when using this image analysis system. Such a system will enable the results of blasting, quarrying, mining and crushing to be cheaply analysed and correlated with current and changing indus- trial practice so leading the way to increased productivity.

Jan 1, 1988

By S Smith

Several styles of copper (Cu) mineralisation are present at Sepon. Large tonnage, low grade skarn and carbonate replacement massive sulfide mineralisation occur within the metamorphic aureole of Permian-aged rhyodacite porphyry intrusions (RDPs). During exhumation and supergene weathering, this primary mineralisation has been upgraded to form high-grade chalcocite enriched zones up to 50 m thick, which comprises the bulk of Cu resources currently being mined at Sepon. Groundwaters remobilise Cu to form exotic accumulations of malachite that are locally hosted in irregular karsts in carbonate rocks, found up to 1000 m from source mineralisation. Khanong is the largest Cu deposit and recent discoveries have been made at Thengkham South, Thengkham North and Phabing. All deposits have formed by similar processes of mineralisation. However, all differ due to local variations in host rock lithology, structural setting, and hydrological conditions. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By J Mauk, R Ruddock

The Taharoa ironsand deposit is 1600 hectares in size and is located 144 km south of Auckland on the west coast of the North Island, New Zealand. The sand predominantly contains heavy mineral-rich sediments, quartz, and feldspars. One hundred and two samples were collected from all areas of the mine, from the stockpile, black sand areas, tailings and Te Akeake Sands. Samples were collected with the primary focus on the next predicted mining path and secondly on gaining a good geographic spread throughout the mine. All samples were analysed for the dry, wet and particle density, the porosity and the magnetic, non-magnetic and clay minerals content.Stockpile samples had an average magnetic mineral content of 92 percent. Dry, wet and particle density values for stockpile material exceed all values from untreated ironsand samples with average values of 2.8g/cm3, 2.9g/cm3 and 4.4g/cm3 respectively. Black sand samples from the mine came from various areas such as the central area, the forest, the southern area and the benches. All black sand samples are remarkably consistent, with dry and wet density values between 2.3 û 2.5g/cm3 and particle densities that range from 3.7 to 3.9g/cm3. The porosity values are comparable to all other areas of the mine (average 37 per cent). The tailings and Te Akeake Sands have different physical properties due to their different mineral contents. The dry, wet and particle densities are all lower than that of all other areas with averages of 2.1g/cm3, 2.2g/cm3 and 3.3g/cm3 respectively. These lower values reflect the lower magnetic mineral content (average 18 per cent) and the associated increase in non-magnetic mineral content (average 78 per cent).

Jan 1, 2002

The process of mine planning at AnacondaÆs nickel and cobalt laterite operation located at Murrin-Murrin in the Northern Goldfields of Western Australia is carried out in a number of stages in an endeavour to determine the optimum mining sequence in order to maintain supply to the 4 Mtpa plant subject to operational constraints. The 296 Mt @ 0.99 per cent Ni and 0.064 per cent Co ore reserve (based on a cut-off grade of 0.8 per cent Nickel) is spread geographically widely over three regions comprising Murrin North (15 km + 15 km), Murrin South (7 km + 16 km) and Murrin East (5 km + 13 km) (refer Figure 2). The nickel mineralisation has been broken up further within each region into 18 separate manageable block models representing the 32 different deposits. The models are based initially on the 50 m + 50 m resource drilling for long term planning and updated with 12.5 m + 12.5 m grade control drilling prior to mining. Each of the individual block models are optimised using Whittle 4X software to provide the shells used as the basis for each of the 126 pit designs. The pits are generally nested with starter pits targeting the higher value shells with subsequent pits incrementally cutting back ultimately to the life of mine shells. A series of steps including: the coding of the individual pits into the block model; data export; TCL scripting (to calculate additional economic and tracking information); importing; and re-blocking; completes the transfer of the data into a MineMax (mixed integer linear programming schedule optimising software) model. Using MineMax and the application of operational and production constraints allows the optimisation, assessment and economic evaluation of alternative scenarios in order to determine the optimum life of mine plan and schedule.

Jan 1, 2003

By S Juras

The terms measured resources and proven reserves denote the highest level of estimation confidence in all of the major classification schemes. But what do they really bring to today’s project or mine with respect to production planning and expectations? Initial reserve declaration does not need measured resources, just indicated resources. Economic viability of a project is assessed on total reserves with nary a bonus for the amount of proven reserves. Production plans are based on grade and tonnage goals that may only coincidently correspond to proven reserves. So are the measured and proven categories still relevant? Historically, and almost exclusively in underground mines, companies only allowed mining in areas of proven reserves. Some companies still follow that philosophy. But many others will mine a mixture of probable and proven reserves without hesitation. Also what of the undeveloped project in a new district – what is to be made of their declared measured resources and proven reserves? Measured resources are commonly set either by some type of proximity to data scheme or a matter of ‘feel’ based on the qualified person’s experience. The parameters for reserve conversion focus on the project as a whole and then a portion becomes classified as proven reserves almost solely based on whether the resource category is measured. So should the mining industry continue to use these categories of resource and reserve classification? This paper will present arguments about making these categories once again more relevant. A more disciplined usage of these categories may re-introduce their relevancy in public disclosures of resources and reserves. As well a more consistent usage in operations may lead to increased confidence in managing production targets and costs.

Aug 22, 2011

The progress of longhole open stoping (LHOS) at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited (ZC/NBHC) is described. The design of a novel sloped wall longhole stoping method at NBHC which should allow the cuplete extraction of the orebody without the formation of pillars and with minimal dilution of the ore with sandfill is reviewed.

Jan 1, 1983

By D Trembath

"One of the key risks to the success of a mining operation is the accuracy of the estimates of both the economic mineral and any accompanying contaminants contained within the ore reserve. Misrepresenting the mineralogical characteristics of the ore reserve can result in considerable financial investment in an operation that is in fact uneconomic and/or carries a significant environmental risk. This in turn can result in an unplanned closure of the operation with associated financial, environmental and social legacy. One way to minimise this risk is to undertake high density resource sampling to gain a better understanding of the resource characteristics. However, such an approach is expensive, time-consuming and often impractical. The risk of not having an accurate model is typically assessed during a feasibility study utilising a Monte Carlo simulation method or some form of sensitivity analysis. Importantly, the error margins used in these types of analyses are often based on subjective or very general criteria such as ‘professional judgement’ or an ‘industry standard’. This presentation introduces a conditional simulation method for developing a range of mineralogical distribution models. Based broadly on the method outlined in Journel and Kyriakidis (2004) the proposed approach develops this work further. It combines a geostatistical analysis of the available data with automated mine design software to provide a rigorous method for assessing the confidence in the mineralogical characterisation of the ore reserve. The process is based on simulating possible mine plans based on the statistical characteristics of the available resource sample data. These plans are then assessed against high resolution resource models generated using a Sequential Gaussian Simulation method. The outcome is confidence intervals for important characteristics of the ore reserve estimate relative to the actual resource. These confidence intervals are an objective and transparent measure important for assessing closure risks and represent an improvement over common practice.CITATION:Trembath, D, 2016. A simulation approach for improving the assessment of closure risks, in Proceedings Life-of-Mine 2016 Conference , pp 36–38 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By D Giles

We present plate tectonic reconstructions, showing that porphyry-type ore deposits are spatially and temporally linked to ridge subduction. A reconstruction of the Peruvian subduction system reveals an immediate metallogenic response to the arrival of the Nazca Ridge at the subduction trench, followed by southward migration of the zone of metallogenic activity due to the lateral migration of the zone of ridge subduction. A similar pattern is recognised in central Chile , where the spatio-temporal distribution of giant ore deposits coincides with the arrival of the Juan Fernandez hotspot chain at the subduction zone. We conclude that there is a spatial and temporal link between ridge subduction and ore deposit formation, with high metal fluxes concentrated in zones of ridge subduction. Thus, the recognition of tectonic patterns associated with ridge subduction can provide insights into predictive mineral discovery by enhancing our ability to predict the position of large mineral deposits in other modern and ancient orogens. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Harrison J

The correct selection of equipment to use in a mine is a problem which constantly faces the mining engineer. In some cases a wide choice of equipment with different operating characteristics is available. If this equipment is to be used to assist in moving the ore it may be possible to build a computer simulation model to predict how it will perform. Typical problems that lend themselves to this type of analysis are presented. The computer models are constructed using a recent form of the GPSS computer language, namely GPSS/PC for the personal computer. This language allows the programmer to construct models in a very short time and at a low cost. Of great importance is the easy way in which it is possible to change the models to answer any of the "what if?" questions the engineer may pose.

Jan 1, 1987

By R Hindstr÷m

The demand for iron ore has increased dramatically in the last years and is forecast to remain on a stable high production level for years to come. ItÆs expected that the world economy is facing a stable continuous growth of iron ore to two billion tonnes and more over the next decades (Beddows, 2007). Furthermore it is expected that the existing and known high-grade ore resources will decline, and the iron ore industry will be forced to implement more and more advanced beneficiation plants. As a consequence of the more complex beneficiation requirements, there will be a need for modern solutions for iron ore dewatering that are reliable mechanically as well as cost effective and with high capacity per unit at the same time. Conventional vacuum filtration methods have been the most prevalent in fine iron ore dewatering. Product quality needs, lower ore grades, complex mineralogy and energy costs have resulted in iron ore producers seeking better solutions for dewatering, in particular pelletising feed. New advanced filtration methods have been introduced to the market. This paper describes how these modern methods are answering the needs of the industry. Performance of advanced dewatering technologies (pressure filtration and ceramic capillary action filtration) for iron ore applications has been studied, and the findings are based on both industrial and pilot scale experiences on different materials. For example, the results show that the cake moisture content of iron ore pelletising feed can be optimised more effectively by using modern filtration technologies. By selecting the most suitable and adjustable equipment, the effects of variations of feed material on downstream processes can be minimised and the possibilities of processing more difficult raw materials to high-quality pellets are better. The Larox Corporation develops, designs and manufactures industrial filters and is a leading technology company in its field. Larox is a full service solution provider in filtration for separating solids from liquids. As such, this paper compares the new developments in this market area with the prevailing known vacuum filtration technology, but focuses on a comparison between capillary action filters and rotary vacuum disc filters (RVDF). The trade name CeramecG is used to differentiate the Larox filter from the generic term.

Jan 1, 2007

Conventionally, a combined system consist- ing of a dry or wet pulverizer and kneading mac- hine is applied to the pretreatment of fine mat- erials for agglomeration, especially for pellet- izing. However, treatment cannot be expected to be satisfactory owing to the complexities of the process. A new process was developed to over- come the defects inherent in the conventional process. This new process treats certain fine materials having a moisture content somewhat lower than that suitable for pelletizing in a ball or rod mill. The mill is of special de- sign in which grinding and strong kneading are performed to give an extremely homogeneous ball- ing material with appropriate size distribution and pelletizing characteristics. The most serious problem in this process is the choking of sticky materials in the mill. A specially designed rubber lining was installed in the mill to overcome this trouble. This paper presents actual results from our iron ore pelletizing plant relating to the pelletization of other fine materials.

Jan 1, 1974

This paper examines the complex interplay of deposit characteristics, mining plans, tailings disposal techniques and rehabilitation requirements on planning for mineral sands operations. All component parts of this mining cycle are interdependent and cannot be evaluated in isolation when optimising a mineral sands operation. This is most evident when projects are large-scale or involve resources that contain complexities such as high slimes content, consolidated hard band materials, acid forming materials and radioactive materials. Projects located in environmentally sensitive areas add further to the need for more stringent planning. This paper describes the analysis techniques adopted by Hatch to evaluate mining and tailings placement options for a dredging and floating concentrator system. The principles and methods used in the analysis are applicable to any mining system involving the complexities listed above. The focus of this paper is on the reconstitution of mined material as tailings and the impact of this process on mining schedules and tailings construction and placement options.

Jan 1, 2001

By Wheatley MR

Answers to the questions "which rocks contain diamonds?" and "which indicator minerals should diamond explorers look for?" are no longer so easily obtained, now that diamonds are known to occur in lamproites and various types of lamprophyres, as well as their traditional source of kimberlites. One way of isolating those factors (host-rock"geochemistry, geographical or tectonic location, xenolith minerals, etc.) which are most critical in determining the diamond potential of a given pipe, is a detailed and critical re-examination of the huge volumes of accumulated data on kimberlites, lamproites and related rocks. A large analytical database to this end has been set up on an Apple Macintosh II microcomputer using the quasi-relational database management system 4th Dimension. Currently, it contains data for up to 90 major and trace elements, isotopic ratios and contained mineral compositions for some 4,000 rock specimens from all over the world. Many experiences in setting up this database are probably relevant to other geologists setting up their own systems: they include determining the relationships between data items; the advantages of codes over free text in representing categorical variables such as rock types; the need for rigorous error trapping and data validation; and the problem of missing data values and ambiguities thereof. The working system is now being used in a rigorous statistical assessment of the criteria which distinguish diamondiferous from non-diamondiferous rocks.

Jan 1, 1989

By M Alston

Organisations’ incident classification processes are plagued by the overclassification of events, often leading to excessive workloads and suboptimal outcomes. This presentation addresses the pressing need to rethink how incidents are classified to maximise organisational learning and minimise systemic risk. A major issue in the current incident classification landscape is the tendency to classify events at high levels, overwhelming organisations with investigations they cannot efficiently handle. This results in inadequate risk reduction and learning opportunities. The link between injury classification and investigation methods further compounds these problems, creating unnecessary administrative clutter. Challenging the misconception that every event, no matter how minor, requires a comprehensive investigation, this presentation advocates for a shift in perspective. The key recommendation is to decouple injury classification and risk matrices from the decision-making process regarding what and how to investigate. Instead, the emphasis should be placed on identifying opportunities for organisational learning and risk reduction. Organisations can streamline their incident management processes by adopting a more pragmatic approach that aligns incident classification with the organisation’s investigation capacity. This transformation focuses on achieving meaningful outcomes, enhancing safety and improving performance. This presentation provides an innovative process for organisations to revamp their incident classification practices, enabling them to harness the full potential of incident data for learning and risk mitigation. It highlights the importance of aligning incident classification with the opportunity for organisational learning, ultimately leading to more effective incident management and enhanced safety outcomes.

Apr 16, 2024

By M Csar

The Nicolsons Find gold project is located 35 km southwest of Halls Creek in the east Kimberley. It was discovered in the late 1980s by John Nicolson and Stuart Skoglund, when high grade gold mineralisation within outcropping gossanous quartz reefs was found. The area has produced a modest 28 150 ounces of gold over two brief mining periods in 1996 and 2002 - 2003. Indicated and inferred resources as of September 2011 stand at 1 384 000 t at 5.58 g/t Au for 248 500 ounces of gold.The project is situated within the Halls Creek Orogen. Principal host units are metasediments and volcaniclastic sediments of the Koongie Park Formation. Minor mafic units are also recognised. Immediately east of these units, emplacement of the loadstone granite is believed to have provided the structural setting for the later gold mineralising event.Mineralisation is hosted within a broad, brittle-ductile arcuate shear zone about the western contact of the Loadstone granite. In the Nicolsons Find area, the shear zone strikes north-northeast and within the shear zone, gold is hosted in a series of narrow, quartz rich veins up to 200 m in strike length, plunging moderately to the north-northeast. To date, mineralisation has been drilled to a depth of 360 m below the surface. The veins are stepped or en-echelon in nature with low gold values towards the quartz vein limits where compression is inferred and higher grades present in the dilational body of the quartz veins. Gold is fine grained and can be present with or without associated sulfides. Sulfides are generally minor and consist mainly of arsenopyrite with traces of chalcopyrite, pyrite and sphalerite. Where present, sulfides are generally indicative of higher gold values.CITATION:Csar, M, 2012. NicolsonÆs Find gold project, East Kimberley, Western Australia, in Proceedings Narrow Vein Mining 2012 , pp 31-36 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012