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Recent data contributions to New Zealand Mesozoic terrane geology confirm the consensus interpretation that New Zealand grew by the progressive addition of material by plutonic and accretionary processes along the Gondwana margin. The data also (1) emphasise the discontinuous but inter-related nature of these processes of continental growth, (2) better establish a direct Gondwana correlation of the Western Province and probable Gondwana provenance of at least some of the Eastern Province, (3) suggest specific times and places when passive or strike-slip rather than subduction regimes are recorded along the south Gondwana margin, and (4) potentially lead to interpretations emphasising parautochthonous rather than far- travelled relationships between many New Zealand terranes.

Jan 1, 1995

By C Smith, D Lilly

The Lafarge Marblehead Plant in Marblehead, Ohio, USA produces 4.2 million tonnes of sized aggregate yearly. In 1997, a program was instituted to maximise primary crusher productivity through the optimisation of blasting variables and procedures. A proprietary blasting shot report database and the Lafarge production database was statistically analysed to provide guidance in the program. Blasting powder factor (kg/m3) was the main control variable utilised to increase crusher throughput. In 2005, the program was refined to increase the production of certain high margin aggregate sizes and the reduction of fines. The principal blasting component affecting the percentage of high margin size production appears to be pattern area (burden and spacing area). This can be coupled with powder factor to optimise the production rate of high margin aggregate sizes. The size optimisation program incorporates the blasting shot report database, Lafarge production database, statistical analysis and aggregate sampling. A preliminary indication is that the production of high margin sizes (12.7 mm X 4.8 mm, 24.4 mm X 12.7 mm, and 50 mm X 25.4 mm) has been increased seven to 12 per cent utilising these techniques. As an added benefit, blasting costs have been reduced linearly as burden û spacing pattern areas have increased and powder factors have decreased. The program is ongoing and will investigate other blasting procedures and variables including electronic blasting caps to further increase the production of high margin products. The statistical methods involved in the analysis are described in this article for use in other mines and situations. The methods described can be used to optimise crusher throughput, digging rates and product size.

Jan 1, 2007

By Hebblewhite B, Humphreys D

An experimental mining project has been carried out in the Collie Basin to demonstrate the safe operation of total extraction mining techniques in the underground mines of the basin. To achieve this, it was necessary to design and install a means of controlling or removing groundwater so that goafing of the overlying strata could be safely achieved as part of the mining operation. The site chosen for the experiment was a triangular panel adjacent to Western No 6 (WD6) underground mine, which includes the 3 to 4 m thick Wyvern Seam beneath 130 to 180 m of overburden. The test area abuts a major fault on the downdip side. The overburden and underburden sequences include several horizons of permeable sandstones which form major aquifers. Water problems have long been recognized in all underground mines in the Collie Basin, and have previously prevented the successful application of total extraction mining. Following extensive hydrological investigations, dewatering and depressurization systems were designed to dewater the immediate roof aquifers and to depressurize aquifers higher in the sequence and in the floor. This would enable stable roof conditions to develop and controlled goafing to be achieved. The roof dewatering/depressurization procedure involved a combination of in-mine vertical roof drainage holes and conventional dewatering bores constructed from the ground surface above the mining trial area. The dewatering system was installed and operated for 29 months before the commencement of mining. Mining was eventually successfully completed in two trial panels using a retreat Wongawilli extraction system using bridge conveyors and continuous miners. Water inflow into the mine workings was channelled to a constructed sump area at the lowermost corner of the panel and pumped to the surface via vertical sump bores. The dewatering and depressurization measures adopted were successful in permitting the first controlled and systematic total extraction recovery of coal from the Collie Basin. This trial mining exercise demonstrated the potential for increasing substantially the recovery of coal from the Collie Basin, where previously recovery rates of around 30 percent from underground mining were commonplace, using only bord and pillar methods.

Jan 1, 1988

By He F, Zhu D

How to monitor and control the support and surrounding strata system on a longwall face effectively is one of the major research problems in ground control. Based on observations on movements of the support and surrounding strata of face No. 2703 of Dongpang colliery, the relationship between the downtime related to support and surrounding strata and other influential factors is analysed systematically in this paper. Monitoring indices and control measures are then determined by taking corresponding downtime as an objective function. When the monitoring method, developed from the above findings, was used on face No. 2703, the downtime due to support and surrounding strata was remarkably reduced, and the face advanced Normally.

Jan 1, 1992

In the late 1970's Western Mining Corporation, Exploration Division considered the purchase of a major multi-element spectrometer as an adjunct to our existing atomic absorption spectrophotometers. The analytical work proposed for the unit included barium, uranium and rare earth elements from Olympic Dam, uranium, sulphur, vanadium and strontium on Yeelirrie type deposits, major element and whole rock analysis, multi-element analysis of samples from the laterite, chromium and manganese exploration programmes and tin and arsenic analysis. These were all analyses that were not readily or easily performed by flame atomic absorption or were where we expected that a simultaneous multi-element instrument would be an advantage. Also the turnaround times for the commercial laboratories was considered unacceptably long for some determinations. Other factors, important when considering the spectrometer were the ability to ensure confidentiality of results and the ability to assign our own priorities and not to have to rely on commercial laboratories. The two techniques considered were X-ray Fluorescence Spectrometry and Inductively Coupled Plasma Optical Emission Spectrometry. The decision was made in favour of the ICP unit for several reasons. The ICP fitted in with our existing methodology, ie samples digested for atomic absorption or colorimetric techniques would also be suitable for ICP analysis and vice versa. The technique was suitable for water samples and for major element analyses and for rare earth elements. X-ray fluorescence spectrometers were installed at the Kambalda and Belmont laboratories and would be available to us for routine checking and for elements not suitable for ICP analysis. The final consideration was price. ICP was considerably cheaper than XRF.

Jan 1, 1987

Polyacrylamide flocculating agent has been used in the Leaching Division of the Risdon Works of the Electrolytic Zinc Co. of Australasia Ltd since October, 1960. Since the introduction, the.: number of thickeners in use in the continu-ous thickening stage has been reduced from eight to three; there has been an increase of 25% in throughput and a reduc-tion of solids in.:thickener overflow from 3-4 gòpòl . solids to 0.5 g.p.l. solids. Reagent addition has been at the rate of 0.25. lb SEPARAN, NP10 per ton solids.Additionally there has been a gain of 3% in current efficiency as the direct result of the addition of SEPARAN NP10 to purified cadmium sulphate solution prior to electrolysis for cadmium metal. A smoother deposit has resulted and it has been possible to increase deposition time between strip-pings from 47 to 71 hours. However, there has been a slight increase the lead content of the cadmium-metal produced.

Jan 1, 1963

By Sarracino R. S

A number of ideal detonation codes are used internationally for estimating the strength of explosives compositions. Important and far reaching decisions by explosives users are ofen based on the predictions of these codes, but since different codes can deliver very different answers for the same composition, there is a strong possibility of decision makers being misled. In order to both provide a sensible basis for comparing the theoretical energy from explosives from different manufacturers and to prevent the entire rating system from slipping into disrepute, it is in the interests of all to reach agreement on fundamental criteria used by detonation codes for detemtining strength. The problem is illustrated by a case history and basic conventions are proposed, specifically the adoption of energy of reaction as a fundamental and code independent indicator of explosive energy, and agreement on disclosure by suppliers of key non-proprietary information. These measures would assist explosives customers in assessing the true strengths of explosives from the strengths calculated by the different ideal Codes.

Jan 1, 1990

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

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

Jan 1, 1993

By Manlapig EV, Mackinnon IDR, Laudr DW

Orebodies at Ok Tedi contain a number of different fluorine bearing minerals. Some of these minerals report to concentrate and are responsible for the presence of the penalty element, fluorine, within the concentrate. Previous analytical work has tended to examine geological samples for content, rather than determine the metallurgical behaviour of the different mineralogical species. This investigation utilised X-Ray Diffraction combined with Scanning Electron Microscope / Electron Microprobe to identify the fluorine bearing minerals in flotation test products. Seven fluorine bearing minerals were identified, viz., talc, phlogopite, amphibole (tremolite and actinolite), sphene, apatite, biotite and clay. Talc was found exclusively in the skam ore type. Phlogopite and amphiboles (tremolite and actinolite) were found to occur in both skarn and porphyry ores, while sphene, apatite, biotite and clay were found only in the porphyry ores. Of the fluorine bearing minerals observed, only talc exhibited natural hydrophobicity to any significant degree. Phlogopite and the amphibole minerals were found to be hydrophillic, whilst the remaining minerals occurred in insufficient quantities to determine the flotation behaviour. Ok Tedi copper concentrate fluorine content prior to skarn ore treatment in the mill (typically 350ppm) was previously identified as deriving from phlogopite, while talc was believed to be the source of intermittent high concentrate fluorine contents when skarn ores were treated. This paper provides supporting evidence for this belief, and reports the nature of fluorine bearing mineral flotation behaviour.

Jan 1, 1997

By Laffin N. W

Invariably when a new plant is cammissioned operations personnel on takeover look at ways and means of reducing certain restrictions and improving process conditions. These improvements are generally of a mechanical/engineering nature with minor metallurgical alterations to fine tune and maximise recovery. Most operations are continually reviewing and updating existing equipment and equipment spares to gain the maximum performance hereby reducing operating costs. Design of current carbon-in-pulp/carbon- in-leach (CIP/CIL) plants has evolved to such a high degree that many of the medium sized plants can have a "blue printed" design from one to the next if the same engineering designer is used.

Jan 1, 1989

By M Schmid

German hard coal mining operations have decreased for more than 40 years. Current political decisions are leading to a discontinuation of subsidised black coal mining by the year 2018. This decision will, however, be reviewed once again in the year 2012. The enormous increases in productivity, which were achieved in previous years, have so far not led to an achievement of market requirements. Coal mining at depth of more than 1200 m in multiple seam environments is not yet competitive in global comparison. In 2008 the 24 faces left in eight mines produced about 20 million tonnes of usable steam coal. Management and the workforce will be reduced in parallel; from today until 2012 by more than half. The average age of personnel is increasing dramatically and nearly no new personnel are recruited. With this background in mind, increasing continuously coal mining productivity becomes more and more difficult. Above all, this goal was reached by mechanisation, then by increasing the mining machine power and then by enhanced machine control systems. The first attempts to automatically operate full face equipment from above ground were in the early 1980s. After successful automation of the face equipment, the emphasis is now on mine logistics. Autonomous monorail transport was introduced and tested in 2007. Since the development rate of machine improvements has its limits, the focus is on the full interaction of the total production system. Here information technology (IT) becomes important; the driver for more productivity. Actual developments aim for the complete and general homogeneous IT infrastructure both above ground as well as underground. The explosive environment needs high level investments in safe technology, eg access points for WLAN and fibre optics for underground use (ATEX certification). New technology availability also drives the enhancements of management and process control systems. Innovations in the mining industry often comprise technology advances through the adoption of well-known technologies. With virtual reality (VR) teaching and training systems advanced computational instruments, both in software and hardware development, were applied in the German coal mining industry for ten years. Widening lists of applications as well as the encouraging achievements show the economical benefits of investing in virtual reality technology both for teaching and training and for knowledge management. The paper discusses the actual technical achievements as well as in IT infrastructure utilisation and also in employment of virtual reality based systems. Special focus and deeper insight will be given to the fibre optics and WLAN hardware integration as well as software developments. The pocket personal computer (PC) is used to enhance underground material transport and data acquisition. The knowledge-based maintenance system (KBMS) integrates real-time virtual reality knowledge elements, such as repair process descriptions. It gives access to expert documentation by intelligent search algorithms and 3D representations of major mining machinery.

Jan 1, 2008

The mechanisms of fragmentation in homogeneous materials and structured rock mass are reviewed. A method previously used to predict vibration damage to the remaining rock is extended and shown to be valid for the prediction of fragmentation in the rock mass removed by blasting. The effectiveness of different explosives in different types of rock blasting is discussed.

Jan 1, 1990

The influence of strongly chemisorbed solutes such as oxygen and sulphur on the rates of reactions at the gas-liquid iron interface is briefly reviewed. Deductions from recent studies of the rates of decarbur- ization of carbon-saturated liquid iron indicate ideal adsorption behaviour for sulphur over a wide temperature and composition range. This is in fair accord with available infor- mation on surface tensions in the Fe-C-S system. Previously unpublished results for the kinetics of the 14C02-CO exchange reaction are in accord with ideal absorption of oxygen on liquid iron. The derived value for the ideal adsorption coefficient of oxygen at 1550¦C is in quantitative agreement with measurements of the depression of surface tension in the Fe-0 system. Consideration is given to the applicability of such results to the violently agitated systems of steelmaking.

Jan 1, 1980

MERLIN, the Queensland Department of Minerals and Energy's corporate geographic information system, provides ready access to all georeferenced data held by the department. Its aim is to provide a consistent, current, statewide coverage of timely information to assist in tenures management, exploration targeting and competing land use decision-making. Initially developed in 1988 and under continual enhancement since then, its functionality is the result of on-going close consultation with a wide range of departmental clients and potential users. A true geographic information system, MERLIN maintains both graphical data with linked textual information on a wide range of features of interest. The proprietary software products Arclnfo and Oracle are used to hold the graphics and attribute information respectively. Access to information is provided by a specially designed graphical user interface programed in-house. Hardcopy output of graphics displays including related attribute data as well as detailed reports of textual information can be retrieved at any departmental office. MERLIN is a network of computer systems which link each of the Department's regional offices and head office in Brisbane. The current state of exploration and mining is maintained by departmental officers processing tenure applications, transactions and dealings directly into the system. Data entered at regional offices are transferred overnight to head office to up-date central records and maintain a currency of data statewide as at the close of business the previous day. Through MERLIN the Department of Minerals and Energy now offers a much streamlined tenures management service as well as access to information about past exploration and mining, Queensland's mineral and energy occurrences and resources, and up-to-date information on the state's geology including maps, boreholes, geophysical surveys and field observations. In the future, this Geographic Information system will be invaluable to the mining industry in the development of mining projects.

Jan 1, 1995

By Grant J

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

Jan 1, 1988

The paper describes the geology, structure, stress, gas and strata geomechanical properties for Leichhardt Colliery and their reactions to mining.

Jan 1, 1986

By L Abrahamsson

The aim with this paper is to discuss experiences from the ongoing research project ‘Attract: A roadmap to attractive, inclusive, and safe mining workplaces’. The project’s aim is to analyse possibilities, effects, and consequences of the green and digital transformation in the Swedish mining industry from workplace, socio-technical and gender equality perspectives. The research project (2022–2025) at Human Work Science at Luleå University of Technology is financed by the strategic innovation program Swedish Mining Innovation (a joint venture by the national research funds Vinnova, Formas and the Swedish Energy Agency). The project includes a multidisciplinary research group of five senior researchers and five PhDstudents and a broad repertoire of methods, eg literature reviews, qualitative interviews with both managers and workers, workplace observations, workshops, surveys, and project seminars where the researchers and the company representatives together analyse the results. One important part of the project is the applied approach where the researchers work together with two mining companies and one subcontractor company. The project has two parallel main subprojects.

Sep 1, 2024

By Gardner H. J, Wadsley m. W

Bauxite from the Weipa and Andoom (North Queensland) deposits was treated to provide a low-iron raw material for high- alumina refractories or aluminium chloride manufacture. The operation involved passing crushed, calcined bauxite continuously through a single laboratory shaft furnace. Consecutive sulfidation and chlorination of the iron minerals within the furnace resulted in a beneficiate containing less than 2% (wt.) Fe203 and by-product ferric chloride con- taining only traces of aluminium.

Jan 1, 1979

By Floyd JM, Bultitude-Paul J

The development of a process for the extraction of antimony from materials produced by Greenbushes Tin Limited has been carried out based on theoretical and laboratory studies. The materials treated have included concentrates of tantalite and cassiterite containing antimony at levels ranging from 0.3% to 2%. Roasting under controlled atmospheres is required to stabilise Sb203 rather than the low vapour pressure metal or higher oxide. Sulphidising additives such as pyrite, pyrrhotite or sulphur give enhanced antimony removal from tantalite and cassiterite at roasting temperatures of 900¦ to 1100¦C. Substantial elimination of antimony to levels of 0.1% or less was Achieved.

Jan 1, 1986

An effective production control system should maximise recovery of economic material from the resource. To do this, internal waste must be accurately delineated and efficiently removed. Achieving this is most difficult in low grade blocks just above and just below the cut off grade, where ore:waste separation follows assay or statistical, rather than geological boundaries. Difficulties arise from sampling errors, configuration of the economic mineralisation, and local variations in geology. Mine bench parameters and mining equipment size apply further constraints to the actual field separation of the ore from the waste. At BCL, management of the resource starts with an effective orebody model for planning, scheduling and ore:waste prediction. Ore production from each mining location is reconciled with concentrator tonnage and grade, and the reconciled grades are compared with the planning orebody model to highlight any Differences.

Jan 1, 1986