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By N B. McCaffrey, V Glenn, C Johns, P D. Erskine, A T. Fletcher

"Underground coal mining is the dominant method of extracting thermal and coking coal in the southern and western coalfields of New South Wales. Monitoring mining-related subsidence forms an important component of environmental impact assessments and subsidence management plans, particularly when there are conflicts between the interests and requirements of mining and environment and community groups. However, there are few specific guidelines for monitoring the impacts of subsidence on terrestrial and aquatic ecosystems, leading to inconsistent policy approaches and highly variable abilities of monitoring programs to accurately detect biological change.This paper highlights the use of a conceptual framework to guide the development of a long-term ecological monitoring program at an underground coalmine in the Western Blue Mountains, New South Wales. Two pilot studies are described: determining the level of observer agreement to assess the condition of a vulnerable tree species (Capertee Stringybark) comparing field sampling methods for detecting a rare heath shrub, Epacris muelleri, using a power analysis to determine sampling intensity requirements.These examples demonstrate that investment in initial pilot studies to test different monitoring approaches can have long-term benefits for stakeholders by more confidently being able to detect potential impacts.CITATION:McCaffrey, N?B,?Glenn, V, Erskine, P?D, Johns,?C?and Fletcher, A?T, 2014. Detecting long-term ecological impacts of subsidence from underground coal mining – a tale of two pilot tests, in Proceedings Life-of-Mine 2014, pp 139–152 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

The areas of impact when employing high productivity long wall systems are reviewed and the financial implications of the most significant areas highlighted. A distinction has been made between availability and utilization. The need for more efficient delay recording, together with increasing control and utilization of the systems has been identified and the measurability of the latter discussed. The increased use of electronic delay reporting direct from the operating unit as the basis for operational control and a pre-emptive maintenance philosophy is seen as an important area of achieving higher performances from existing long wall production systems and Configurations.

Jan 1, 1988

By Yokozawa K, Yamamoto T, Kameoka Y

Japan Construction Method and Machinery Research Institute has been conducting various field surveys of tunnel works and other excavation works, and the cost and efficiency of these two excavation methods have been studied. Based on these data, the costs of blasting excavation and mechanical excavation represented by roadheaders were calculated. The costs were calculated and compared for rocks of various hardness. When the total construction cost is considered, the degree of overbreak becomes one of the most influencial factors, because the overbreak area must be filled up with expensive shotcrete in NATM. So, in the next step, the relation between the excavation costs considering overbreak and the rock hardness was studied using the data on overbreak obtained by the field survey.

Jan 1, 1987

By Tran T, Young D

During the processing of gold, effluents that are discharged into the tailing dams contain free cyanide, metal cyanide complexes of zinc, copper, iron, etc and their oxidised products such as ammonia, cyanate and thiocyanate. A knowledge of how different cyanides behave in the solution is vital to metallurgists working in the area of cyanide waste treatment. Although the free cyanide ion is not stable in aqueous solutions and is expected to degrade in a natural environment by atmospheric oxidation, the metal cyanide complexes, especially of iron, are very stable. The CHEMIX program from the THERMODATA package, developed by the CSIRO Division of Mineral Products, was used to evaluate various copper-cyanide and iron-cyanide systems. The simulation of these systems show how the free cyanide and cyanide complexes behave at different conditions of solution composition and acidity (pH).

Jan 1, 1991

Rajasthan of western India blessed with rich base metal and phosphorite deposits. The biogeochemical and geobotanical methods of mineral exploration are greatly used in parts of Rajasthan Zawar, Khetri and Ambaj multi-metal project Gujarat and Jhamarkotra phosphorite deposit. These principles are exclusively based on certain assumptions about the anomalous chemical composition in plants and distribution and migration of indicator elements. Biogeochemical studies for lead zinc deposit of Zawar group of mines were carried out to locate the probable accumulators which could help in prospecting for these metals. The important roots of Impatiens balsamia plants contain 735 mg. of cadmium and crotolaria linifolia 603 mg., melhania futteyporensis 626 mg. lindenbergia muraria 443, celosiu argentia 360 mg. In the Khetri copper belt the vegetation is scanty and the species includes Acacia arabica, zyzypus jujuba and cactus euphorbia.

Jan 1, 1988

A number of cooperative studies have been carried out as preliminary work for drafting a standard for application of granulated slag sand for concrete, and the following conclusions were reached 1 The ten kinds of granulated slag sands pro- duced in Japan satisfy the national standard for fine aggregate in terms of physical and chemical properties. 2 Mortar and concrete tests conducted with granulated slag sand revealed that, although with slight differences in the extent, gran- ulated slag sands used in these tests were applicable'as fine aggregate for concrete, 3 The pumpability test by a concrete pump carried out on concrete with two kinds of now commercially available granulated slag sand demonstrated that the pump pressure feeding is applicable in the same manner as in the case of ordinary concrete. These tests permitted' preparation of a draft standard for application of granulated slag sand, and the results formed the first step toward utilizing this material as a sub- stitute for natural sand.

Jan 1, 1979

By Olson H, Kincaid R

The marine portion of the Pacific Basin and Rim constitutes a significant part of the world's surface in which the mineral resources are virtually undeveloped. Indications of substantial resources have resulted in speculation and uncertainty with regard to their potential in the near term. The main issues are centered on the markets for the resource materials, the technology needs for their recovery, and the possible impacts of their development on the environment. While the governments of Japan, France, the Soviet Union, India, China, and Korea are financing new programs in deep ocean mining, the US is consolidating its early leadership by the continuation of NOAA's authority under the Deep Seabed Hard Mineral Resources Act and the Sea Grant Act, Interior's authority under the outer Continental Shelf Lands Act, and by the development of a new Marine Minerals Technology Center within the Department of Interior's mineral institutes program, managed by the U.S. Bureau of Mines. The Center has a Continental Shelf Division (CSD) located in Mississippi, and an Oceans Basin Division (OBD) located in Hawaii. Research and training in the divisions is directed toward the practical aspects of mineral recovery from the nearshore and deep ocean environments with a strong bias for the OBD toward industrial and international cooperative programs in the Pacific Basin and Rim. In terms of resource development, the marine minerals in the Pacific Basin may be favored in some cases, in competition with land sources, by political and environmental considerations.

Jan 1, 1990

By P Krauss, S Harpalani

Methane emitted from underground coal mines, along with ventilation air and known as ventilation air methane (VAM), constitutes the largest component of coal mine methane (CMM) emissions. Atmospheric methane, on the other hand, is a potent greenhouse gas with a significant adverse impact on the atmosphere. This has led to the development of various technological alternatives for its use as an energy fuel. Techniques involving oxidation of VAM, usually consisting of very low concentrations of methane, have been validated in the past. Prominent among these technologies are the thermal and catalytic flow reversal reactors, ancillary fuel technologies, lean fuel gas turbines, and concentrators and gasifiers. However, the efficiency of any VAM utilisation technique depends on the amount and concentration of methane in the ventilation exhaust air. Therefore, quantification of VAM emission from a coal mine is the first step towards identifying the most suitable technology for its utilisation for energy production. This paper presents an evaluation of the efficacy of VAM as an energy source. It provides details of a case study aimed at developing a technique to accurately quantify VAM emission from a coal mine. It further discusses the various VAM utilisation techniques available, and presents an economic evaluation of the alternatives. Based on the findings of the study, the most feasible method for VAM utilisation is identified for the mine. The paper summarises the procedure for quantifying VAM emissions and selecting the most suitable utilisation technique.

Jan 1, 2005

By Pandey A. K, Srivastava A, Das A

Drilling and blasting constitute important activity in mining operations and account for around 20% of the total excavation cost. The utilization coefficient of energy for explosions of the fragmentation type is hardly 15 to 2035 and an enhancement in this is possible only through optimization of blast design. Designing a 'blast is a complex planning task, which for optimum results calls for matching the energy level of the explosive, rock properties and bench geometry. Optimum blast design needs a comprehensive study and an objective analysis of the intersecting elements. A cost optimised approach is often adopted with due consideration for all the cost sectors viz., drilling, blasting, loading, hauling dumping, and primary crushing, contributing to the overall miring cost. The present study deals with a performance prediction model which predicts the optimum burden for an explosive system in a given rock type to produce a certain desired fragment size. The model is framed on the inputs : shovel size, drill size, unit cost of drilling, bench dimensions, rock density, bond index, unit cost of explosive, maximum work potential. The model has been extended to compute the drilling and blasting costs for an assumed size of the bench to be blasted per round, so as to arrive at the overall cost optimization from a number of explosive systems. A comparative cost calculation with different explosive systems has been presented for a typical iron ore mine in India.

Jan 1, 1990

Underground mines in Australia and worldwide are extending to greater depths. The effect of depth brings a number of challenges to mining engineers including geotechnical, ventilation, haulage and selection of mining method. The main effects of depth from a ventilation perspective are increased heat and humidity leading to reductions in productivity, occupational safety and health issues and the potential for fatalities. Numerous approaches have been undertaken over the years to mitigate against these effects. In this paper a review of various approaches to improving climatic conditions at a number of mine sites worldwide is undertaken. From these case studies it is argued that for mines at depth with the potential for a climate problem perhaps an alternative design philosophy to the established design philosophy should be utilised. In conclusion, the paper proposes some simple rules of thumb for use in mines with climate problems or the potential for climate problems.

Jan 1, 2008

The treatment of nickel ores and concentrates and the subsequent processing to recover separate products of nickel and cobalt is one of the major interests at present in the mining industry. The increasing demand for nickel, and more recently also cobalt, has led to increased exploration for ore sources. Major discoveries have resulted in Canada and Australia. These deposits, as well as others already known, are presently being developed and the process technology tested and evaluated for applicability to the different mineralogical types - mainly sulphide, arsenide and oxide laterites. Concentrates may be treated by either hydro- or pyrometallurgical processes, while the nickel laterites are best suited to hydrometallurgical processing. However, if hydrometallurgy is used, once the ore or concentrate is leached the resultant solutions are then amenable to similar separation technologies for purification and recovery of high purity nickel and cobalt products. Solvent extraction, together with other separation processes such as precipitation, can produce high purity solutions of nickel and cobalt. The final products of these solutions may be nickel and cobalt cathodes, metal powders precipitates or salts, depending on the final process of electrowinning, hydrogen reduction, precipitation, or crystallisation Respectively.

Jan 1, 1996

By KeBler H-W, Seeliger A

Vibration analysis for diagnosis of machines is a powerful instrument for condition monitoring. Especially for diagnosis of antifriction bearings various equipment and techniques have been developed and are available. The envelope analysis is the most reliable method for bearing diagnosis. Different bearing failures lead to different patterns of the envelope spectrum. Checking the amplitudes of characteristic bearing frequencies is mostly not sufficient for a reliable diagnosis. Therefore human experts compare the pattern of the spectrum with typical patterns of bearing defects. In this paper a diagnosis system is presented which imitates this action of human experts. Using a neural net the system not only distinguishes typical bearing defects but also detects unbalance, beating of disengaged machine parts and other kinds of machine failures.

Jan 1, 1995

By Brien R. J, O&apos

Faster and more efficient methods of producing and refining iron and steel are imposing severe conditions on the refractory materials used to contain these metals in the molten state. In order to provide refractory linings which will give the desired service life and maintain unit availability at an economical level, it is necessary to appreciate the aggressive environment in which the refractories operate and determine the reaction mechanisms by which the refractories are destroyed. Only by such studies can the most suitable refractory or refractory combination for a particular unit be selected. Examples of refractories selection and reaction mechanisms are discussed for blast furnaces, BOS vessels, AOD vessels, steel ladles, vacuum degassing units and continuous casting.

Jan 1, 1976

By J L. Merritt

Effective minesite water management requires that this issue be treated as a risk management exercise. The management process is generally far from simple and by necessity must involve a range of personnel covering a siteÆs commercial, operational and environmental interests and responsibilities. The challenge to be collectively faced by these stakeholders is to strike the correct balance between risk and cost. On the other hand, the challenge to be faced by technical services support personnel is to provide stakeholders with information in a format that they can use with confidence. This paper presents the application of continuous operational simulation (OPSIM) modelling techniques to establish appropriate risk profiles for minesite operations. It is necessary that the format of these risk profiles be generic and equally applicable for defining the risk of occurrence for a relatively comprehensive range of activities û eg from of a non-compliant discharge, to the risk of failure to meet production targets. What is more, the profiles need to be quantitatively based and capable of reflecting change in system response to varied operational or management strategies. The techniques presented in this paper are based around a key assumption that long-term records of the climate contain within them sets of sequences that are representative of what can be expected in the future û that is, the droughts, floods, cyclones, good years and bad, long or short, and everything in between. Therefore, if these historical records are run through an OPSIM model for a particular site, then the simulated operational characteristics can be taken as being representative of what can be expected in the future, in the long-term. This lends itself to statistical analysis and translation into the required risk based format. Water Solutions Pty Ltd have been working with Capricorn Coal Management to develop a relatively comprehensive OPSIM model of their operations at German Creek Mine, Central Queensland. Outcomes from the modelling have been used in recent times to provide mine management with risk-based guidelines for both securing and containing mine water inventories. One of the more interesting tasks has been to establish risk based inventory levels that, if reached, would trigger the immediate implementation of a contract for the desalination and re-use of mine water, at predefined rates. Also, lead-time warning of the occurrence of a possible trigger is of importance to operational and commercial planning. To service this requirement the OPSIM model is regularly used to produce lead-time estimates to defined levels of confidence. Case studies of these, and other, applications of the OPSIM model at German Creek Mine are presented in this paper and serve to demonstrate an effective methodology for practical risked based water management.

Jan 1, 2003

By Seedsman RW, Duncan Fama ME

Mine design procedures will be revolu- tionised by technological developments in computers, software, database construction and management, and numerical modelling programs. Developments in geotechnical databases will be required which utilize geological and geomechanical tests to supply appropriate input for numerical models. Techniques utilizing sedimentological and structural modelling are described. The capacity of current numerical models in mine design is outlined and a program for developing a fully integrated mine design package proposed.

Jan 1, 1987

Various factors influence the exploration geologist or geochemist in his choice of.an analytical method for gold and other elements which may help him find the elusive gold deposit. One of the first decisions the geologist must make is the nature of sample media to collect for his survey. Needless to say there are many media available depending on the situation. These include rocks, soils, heavy mineral concentrates (from overburden drilling and panned concentrates), humus, vegetation, water, lake bottom sediments, stream sediments, etc. The choice of the sample media will depend to a large degree on the state of development of the particular project from grassroots to mine feasibility. The nature of the geological information required will affect which media and which analytical technique should be chosen for the analysis. Valid sampling from the initial sample collection, preparation and subsampling aspects may also help to determine which analytical procedure is best. Cost and turnaround time are of prime. importance to the explorationist, as it should be, however, these aspects should not be detached from receiving accurate and reliable results.

Jan 1, 1987

A comprehensive understanding of the rocks associated with coal seams, and also of the coal itself, is essential in assessing the likely behaviour of the materials before, during and after the mining process. The nature of the rock materials involved in coal mining can give rise to risks from adverse geomechanical properties, create problems in coal quality control and produce difficulties with environmental impacts, all of which may affect the profitability, impact and safety of the operation. Examples of issues associated with rock composition include slaking and degradation leading to roof, floor, pit wall or spoil pile instability, ignition of methane in mine atmospheres by frictional processes, liberation of quartz-rich dusts into ventilation systems, production of coal with unfavourable preparation or marketing characteristics, and escape of suspended solids or potentially toxic leachates from spoil piles and other types of emplacements. Methods for evaluating rock composition include microscopic examination, chemical analysis and X-ray diffraction, with the latter being especially useful for fine-grained rocks or for clay-bearing materials. Other techniques, such as geomechanical testing and down-hole geophysical logging, are also useful, but give less direct information about the actual composition of the materials involved. Indeed, understanding of rock composition, through microscope or quantitative X-ray diffraction studies, provides a basis for checking information from other sources, explaining different aspects of rock behaviour, and an essential link in relating geophysical or geotechnical data to broader-based geological models as part of the risk assessment process.

Jan 1, 2003

By A B. Bell

The health and in some cases survival of mineral exploration and mining companies is, in today's markets, more dependant than ever on the effective use of information technology. The need for speedy collection, organisation, maintenance and distribution of corporate and project information is a phenomenon that will continue to strengthen with market thirst.Geographic Information Systems (GIS) provide a medium for storage, maintenance and retrieval of data, and Internet Mapping adds a technology for effective distribution of that data. Combining these technologies can return benefits both fiscally and technically by reducing costs of ownership in IT infrastructure and increasing the efficiency and effectiveness of both internal and external information delivery.GIS and Internet Mapping technologies have reached a practical stanza in their evolution and will continue to develop as a key business tool in the natural resources sector.

Jan 1, 2002

By N Stockton

Some preliminary results on the secondary leaching of previously heap leached gold ore are presented. Alternative lixiviants for gold comprising chlorine, thiourea and thiosulphate were compared with cyanide using bottle roll tests. Chlorine was subsequently selected for column leaching tests. Column tests at 1.0, 0.1 and 0.01 gL-1 Cl2 at pH 2 were conducted. The results indicated that about 23 per cent of the gold was leached over 45 days using 1 gL-1 Cl2 at pH 2. The experiments conducted proved that the chlorine/chloride system has good potential for further extraction of gold and silver from the existing cyanide heap leach residues and a process for secondary leaching of gold has been proposed. Further testwork is recommended to extend conditions, sample types, and the duration of leaching period.

Jan 1, 2000

The prime requirement is market, which for NZ inevitably means overseas markets. In order to be internationally competitive, the economies of scale and mechanical handling are essential. Since significant markets have not been sought, the full extent of our industrial mineral potential is not known. In general the technology exists to impart the desired quality, but at a price. Price is the main constraint, which may confine truly competitive operations to coastal situations to avoid high internal freight charges. Some commercial deposits of construction materials are being sterilised by zoning, making the costs to the consumer and country unnecessarily high. Unless management is enlightened and marketing is forceful, it can restrict growth. There is a good case to mount a search for phosphate minerals. The main growth areas are likely to be direct shipping ores like limestone, silica sand, and olivine, but in particular pumice.

Jan 1, 1978