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By S Pontual

Compact and field portable infrared spectrometers have been increasingly used over the past few years by an exploration industry constantly searching for a technological edge and the ability to more accurately and rapidly assess project areas. In particular, this technology allows large amounts of data to be rapidly collected on-site and sample mineralogy, mineral crystallinity and mineral composition to be quickly assessed. In recent years, short wave infrared (SWIR) reflectance spectroscopy has proved useful in a wide range of geological environments and at various stages of exploration programs, from grass roots reconnaissance through drilling programs and resource evaluation. Unfortunately these data have frequently been analysed and interpreted in isolation using time consuming data analysis techniques removed from the realities of a fast moving exploration industry. This paper presents new analysis techniques which allow these data to be efficiently integrated in the exploration program. Although SWIR data contain a wealth of mineral information it is impractical to use this information in its raw form. A more effective approach involves the extraction of key characteristics of these data (ie mineralogy, mineral composition and crystallinity) as numerical values, and the integration of this ædigital mineralogyÆ with more conventional exploration datasets (eg geochemistry, coordinate data, etc). This paper demonstrates that the integrated analysis of sound geological observations, geochemical, spatial and spectral data can quickly lead to a greater understanding of the nature and distribution of target mineralisation. As a first step, software driven pattern matching routines enable the identification of the major clay mineral species in a series of samples (eg kaolinite, montmorillonite and sericite). This allows the major alteration facies and their spatial distribution to be identified. Quantification of diagnostic absorption feature characteristics then allows more accurate determinations of mineralogy to be made (eg mineral composition and crystallinity). Examples of the application of SWIR analysis for alteration mapping from selected porphyry and epithermal systems from around the Pacific Rim are discussed. The data presented are derived from a variety of locations and sample types including drill core, ridge and spur rock chip samples, soil samples and geochemical pulps. In these large alteration systems, the spectral data can be used to describe and map the distribution of various alteration facies as many of these are characterised by clay and phyllosilicate mineral assemblages and are detected by SWIR analysis (eg smectite, chlorite, biotite, illite, muscovite, kaolinite, dickite, pyrophyllite, alunite, etc). In addition, the ability to evaluate even subtle trends in mineral crystallinity and composition is often vital in these systems when looking for vectors towards higher temperature parts of the system. In addition to detailed evaluation of mineralogy, the integration of digital mineralogy data with geochemical data leads to the ability to describe not only geochemically anomalous intersections or regions but also to recognise associations between subtle changes in mineralogy and target mineralisation. This is often important because understanding these mineralogical associations can lead to more accurate targeting and rapid assessment of the project.

Jan 1, 1999

By Moxon N. T

The detonation pressure of ANFO can be significantly reduced by the addition of low density materials such as polystyrene, bagasse, swadust or perlite. Laboratory and field test results have shown that homogene- ous mixtures of these low density explosives can be produced in a bowl truck and loaded into a blasthole without segregation. The detonation pressure of the mixture can be altered to be more compatible with the material in which it is being used by varying the quantity of low density additive incorporated into the mixture. Field results have shown that these low density explosives can lead to significant cost savings without com- promising fragmentation or production.

Jan 1, 1989

The Porgera mine and treatment plant are located in the Enga Province of Papua New Guinea. Gold in the Porgera deposit is found free and in association with the primary sulphide mineral pyrite. The refractory nature of the gold in the pyrite r

Jan 1, 1997

By Boontanjai C, Boyapati ER

Reagents used for batch flotation tests were Aeroxanthate-343 & 350, Dow Z-6, & reagent-4037 (from Benambra) as copper collectors; Na2SiO3 & Na2S2O3as gangue depressants; lime & HCl as pH regulators; and pine oil & MIBC (methyl isobutyl carbinol) as flotation frothers. A Denver Sub A flotation cell of capacity 250 gms was used for the batch flotation experiments. Atomic absorption spectrophotometer was used for copper assays and microscopy for selectivity and liberation studies. Melbourne tap water was used throughout the experiments. Unless otherwise stated, the following parameters apply to the flotation experiments: flotation impeller speed - 1300 rpm, pulp density during flotation- 22%, reagents addition - in 4 stages, total conditioning time for collectors - 8 minutes, total flotation time- 9 minutes. A variable quantity of copper mineral collector according to the test in question was added, then conditioned the pulp for 2 minutes. The froth was removed by hand, scraping the full length of the cell at constant depth every 10 seconds. No frother is required for this copper tailing flotation. Four concentrates were collected after addition of collector and conditioning at 2,4,6 and 9 minutes. The pulp volume was maintained at a constant level to yield a constant froth depth.

Jan 1, 1990

By B N. Morrison

In all metallurgical plants metallurgists require analyses of the various intermediate products, eg flotation feeds, flotation concentrates, tailings, mattes, slags, etc to monitor the efficiency of the plant processes and for plant control purposes. Traditionally these samples have gone to off-site laboratories and there can be some considerable delay before analytical data are received. On-line monitors have to be used for plant control purposes and these are difficult to maintain and can give poor quality data. Recent technological advances in automation in analytical laboratories now allow a far quicker turn-around time for analytical data so they can be of more use to the metallurgist. Automation, which involves the use of robots and fewer people in laboratories, has the added benefit of providing higher quality data as the possibility of human error and bias is minimised. Differences between conventional manual laboratories and automated laboratories are described. Automated analytical laboratories are now becoming the laboratories of choice for mining companies which require large numbers of samples to be analysed on a 24/7 basis on similar sample types using the same sample preparation methods and analytical procedures. Automated laboratories have now been installed in platinum, iron ore, copper and aluminium producing mining companies. A further advantage to metallurgical plants is now the possibility of siting automated analytical laboratories in-plant and designing the plant around the laboratory. Concentrator streams, slags, etc can be sampled by automated samplers, the samples transferred by automation to the in-plant laboratories and all sample preparation and analyses carried out by automated processes. These laboratories require a minimum of staff. Such automated in-plant laboratories have been installed on a platinum mine flotation plant, a platinum mine smelter and steel plants. One is in process of being installed on an iron-ore mine with the sampling being carried out by an automated sampling tower. The procedures followed in planning an automated analytical laboratory for a metallurgical plant are described in detail in the paper. The platinum plant smelter automated system which includes rapid transport of samples by air-tube to the laboratory for the analysis of the samples by XRFS is also described in the paper. It is concluded that automated analytical laboratories can be retro-fitted to most metallurgical plants but they are best suited to greenfield sites.

Jan 1, 2008

By Liu H, Chen S

Natroalunite is one of colouring minerals in kaolin. In this investigation, natroalunite, on which Ca(II) was adsorbed, was flocculated by HPAM and kaolin was depressed in suspension. The adsorption of Ca(II) on the natroalunite surface was studied by zeta-potential measurement and Auger Electron Spectroscopy analysis. Ca(II) was adsorbed more on the natroalunite surface than on the kaolin surface. The mechanism of Ca(II) adsorption was considered to be chemical adsorption on natroalunite and to be physical adsorption on kaolin. It has been found that Na6P6O18 and Na2Si04 can strongly affect Ca(II) adsorption on the surface of kaolin, but weakly on the surface of natroalunite. The effects of degree of hydrolysis and the molecular weight of HPAM, the effect of pH and the effect of Ca(II) have been studied. The kaolin ore, containing SO3 1.05 per cent has been processed with this method. The products only containing S03 0.36 per cent and the weight ratio of concentrate 52.27 per cent were Obtained.

Jan 1, 1993

By Leggate J

In the past many coal mining projects commenced without any consideration being given to eventual site rehabilitation. Now that site rehabilitation is assuming greater importance with changing community expectations, and standards are becoming less negotiable, it cannot be ignored in either the development of mine working plans or economic models. The "unspecified" rehabilitation measures associated with many existing projects will be the subject of debate for some time to come yet. It would be wise to plan for the future. Once an agreeed standard of rehabilitation is accepted, good management involves considering practices which will facilitate eventual rehabilitation at least cost. Without planning for rehabilitation, many mines have adopted practices which are likely to result in very expensive rehabilitation measures and impact significantly on the overall profitability of the ventures. With adequate planning, procedures can be developed which achieve the same short term goals without significantly effecting cash flow but with very significant impacts on the final rehabilitation cost. This paper looks at the disposal of tailings and overburden in the coal mining process. The industry has in the past had an obvious preference for the "perceived" cheaper procedures for waste management such as wet disposal of tailings and high dumping of overburden. There are alternatives. The paper discusses the principles which should be incorporated into tailings and overburden disposal systems and identifies viable alternatives.

Jan 1, 1991

By Holliday RJ

The Imperial Smelting Furnace (ISF) was developed in Britain during the 1950's as a process which could produce zinc from a blast furnace. Since then it has evolved into an efficient means of producing zinc and lead from lower grade raw materials, both of primary and secondary origin. These changes have been in response to the need to improve the cost competitive position of the ISF in a climate of decreasing metal prices. The improvements at the Cockle Creek smelter of Sulphide Corporation Pty Limited have resulted from work undertaken in four main areas: 1. Changes in plant design and operating practice to give more stable furnace operation. 2. Improvements to the quality of sinter being charged to the furnace. 3. Improved monitoring of process variables and the formulation of control strategies based on the improved data. 4. Increased understanding of the processes occuring within the furnace shaft to allow predictive modelling to be undertaken. Work in these areas is still progressing but the work to date has resulted in a significant improvement in the production rate and efficiency of operation.

Jan 1, 1984

Mining of narrow vein mineralisation, invariably depending on the mining method selected, involves the extraction of both ore and waste rock. The level to which mining of waste rock can be minimised depends on numerous factors, but particularly the thickness and dip of the deposit. Resue mining is a method of mining that allows split face firing within stopes to allow waste and ore to be mined separately, allowing dilution to be minimised. This paper examines the technique of resue firing and its applicability to the mining of narrow vein deposits. Particular emphasis is placed on the conditions in which resue mining presents a suitable option for mining of narrow veins.

Jan 1, 2008

By Pyrih R, House A, Shangraw J, Silva AJ

Sunbeam Mining -Corporation has the inten mine with heap leach gold recovery, near spent ore indicated a relatively high ar topographical configuration, the spent across a small drainage and a lake. Du permit for spent ore disposal from th agencies, concerns about the potential contamination by the arsenic were expres conducted extensive studies to addre contamination. These studies consiste( geochemical and geotechnical parameters underlying the proposed disposal si geotechnical investigations were also hydrologic characteristics were include with the use of an IBM PC computer. :ion of opening an open pit gold Stanley, Idaho. Testing of the ?enic content. Due to the local ore was planned to be disposed :ing the process of obtaining a federal and state regulatory for surface and ground water .ed. Sunbeam Mining Corporation is the potential for arsenic of laboratory testing of both of the spent ore, and the soils te. Field hydrogeologic and -onducted. Local climatic and 1 in the analysis of these data Conclusions of studies indicated that although the seepage through the spent ore disposal would contain an elevated dissolved arsenic content, the hydrologic and geochemical characteristics of the site would prevent arsenic migration into the local ground water system. The attenuation of arsenic on soils with high clay content, and dilution after reaching the ground water table would lower the arsenic content to acceptable Concentrations.

Jan 1, 1988

The hoisting system at the Newcrest Telfer mine is designed for a final duty of 7.35 million tonnes per annum at a hoisting distance of 1450 m. In terms of hoisting capacity (t/h) times hoisting distance it is one of the largest friction hoist installations. Initially, the hoist will be equipped for hoisting 6.5 Mtpa from 1100 m depth. This new drive technology is now well proven by ABB for mine hoist applications with the first installation in commercial operation since July 2001. To date 17 systems for medium voltage drives and another five for low voltage drives have been purchased from ABB for mine hoists. This paper will also deal with skip design and powerful data loggers with diagnostics for local and remote monitoring that are installed in the Telfer mine hoist.

Jan 1, 2005

By I D. Hair

A numerical groundwater model was used to predict the nature of interactions between heavy mineral sands mining operations and the groundwater regime at North Stradbroke Island, Southeast Queensland. North Stradbroke Island is formed mainly of massive vegetated Cainozoic aged dune sands. Since the 1950s, a number of operations have mined rutile, zircon and ilmenite on North Stradbroke Island. In such mining operations, a dredge and an associated processing plant are floated in a pond either above or below the prime groundwater table The numerical model was based on the North Stradbroke Island Groundwater Management Model, developed in 2001 by the Department of Natural Resources and Mines (NR&M). This model was constructed using the modular, cell-centred, finite-difference groundwater flow model, MODFLOW, developed by the United States Geological Survey (USGS). The NR&M model was refined to improve model resolution and detail for simulating dredge mine paths. Of particular interest were: water table fluctuations induced by mining for the identification of slope stability risk; the optimisation of sand spear arrays supplying mine make-up water requirements; inflow and outflow rates to the dredge pond for overall mine water balance; and interactions with Eighteen Mile Swamp and water supply bores controlled by the Redland Shire Council (RSC). Depending on the water level in the dredge pond compared with the surrounding groundwater table, water either flows out of the dredge pond into the groundwater regime or from the groundwater system into the dredge pond. The MODFLOW river package (RIV) was utilised for the modelling study. Dredge pond movement was simulated using specialised software developed by Watermark Numerical Computing (WNC) to interpolate pond positions and map the dredge path to the model grid both spatially and temporally. As tailings placement affects the groundwater system through increased recharge, the MODFLOW recharge package (RCH) was utilised to simulate different recharge efficiencies. Long-term model predictions were made for the period from July 2002 to May 2021. Results of the modelling showed that exchanges of flow between mining operations and the groundwater regime could be effectively managed. The study provided valuable information which was used to develop an appropriate mine water management plan.

Jan 1, 2003

A non-contacting under-belt capacitance and gamma-ray backscatter technique has been developed for the on-line measurement of moisture in coal. In this technique, moisture was correlated with radio frequency susceptance and conductance determined using an under-belt capacitance sensor in which a fringing electric field Interrogates a layer of coal on the conveyor belt directly above the sensor. To compensate for variations in the density and thickness of the coal layer, an under-belt gamma-ray backscatter gauge was used to measure an equivalent volume of coal.A plant trial of the technique was conducted at Stockton Borehole Colliery, SW Australia, where the gauges were installed on the coking coal product conveyor. Product moistures, in the range 7 - 14%, were determined with r.m.s errors of 0.50 and 0.25 wt% using on-belt and static off-belt gauges, respectively. The difference in the on-belt and off-belt gauge measurement accuracy was attributed to sampling errors in the calibration of the onbelt gauge.

Jan 1, 1989

The design and operating characteristics of the hydraulic cyclone elutriator were described in detail by Kelsall and McAdam (1963), and the method of operation of the commercially available version, the Cyclosizer, is described in the manufacturer's pamphlet (Anon). Complete details of the operating procedure are given in the relevant operating manual (Anon, 1964).The cyclones which form the basis of the Cyclosizer (Fig. 1) under normal operating conditions produce typical cut sizes of 44, 33, 23, 15, and 10 µm for cyclones one to five respectively for material with a specific gravity of 2·7. At the end of the selected elutriation period each sized fraction is discharged and collected for subsequent assay or analysis but all material rejected by the fifth cyclone (e.g. minus 10 \lm quartz) normally passes to waste. When this material is needed for separate study, although its amount and average analyses can be calculated by difference, it may be necessary to collect more than 250 I. of very dilute suspension, flocculate the solids, allow to settle, and decant off the supernatant liquid.This procedure is cumbersome and inconvenient and the simple technique to be described may offer some advantages. The temperature of the water fed to the Cyclosizer is maintained at a constant value for added reproducibility.PROCEDUREThe present overall treatment of the subsieve material (minus 37 \lm) fed to the Cyclosizer incorporated several refinements compared with normal operation and these may be best illustrated by anactual example. Material to be cyclosized (25 to 100 g depending on size distributIOn and specific gravity) is completely dispersed in water at 23 QC by vigorous stirrmg, using suitable dispersants if necessary, in a...

Jan 1, 1974

By M Dorricott

This paper describes the design, construction and performance of sill pillars using cemented development mullock at the Crusader Gold Mine. The orebody is some 35 m - 60 m in length, 5 m - 8 m wide, dipping at 60¦ - 85¦ and plunging at about 40¦ to the north. It is accessed via a footwall decline. The ore occurs at the contact between basalt and ultramafic. This contact is characterised by shearing and alteration; and is prone to unraveling failure. The cut and fill mining method at Crusader extracts 25 m high ore blocks in four flat back lifts and one 8 m thick crown pillar. To enable full recovery of these high-grade crown pillars with minimal dilution, a 5 m thick sill pillar is constructed using cemented rock fill (CRF), after mining of the bottom two lifts in each block. Uncemented development mullock is used as rock fill (RF) for subsequent lifts. Development mullock and cement/water slurry is mixed underground to produce CRF. The fill is transported to the stope in LHDs and dumped on the floor. The sill pillar is advanced progressively, with compaction provided by the loader driving over the previously placed fill. Old jumbo rods are installed as shear pins along the flat dipping hangingwall to reduce the risk of rotational failure of the pillar. A fan of cable bolts is installed into the hangingwall to prevent unraveling failure in the sheared ground. Buffer blasting is used to minimise damage to the CRF sill pillar when the crown pillar below is extracted. At the time of writing, extraction of the crown pillar underneath the CRF has taken place at the 930 stope. The crown pillar was extracted successfully with dilution from the backfill and hangingwall minimised and 98 per cent of the gold recovered. This compares with pillars that were mined beneath uncemented backfill where only 70 per cent of the gold was recovered and where there was significant dilution from the backfill and from hangingwall failures. Where no CRF was placed, there were also numerous production delays caused by large rocks from the hangingwall blocking the stope brow.

Jan 1, 2002

Gold mineralisation at the Macraes Gold Project is hosted in the Hyde-Macraes shear zone and can be traced for ~30km along strike, although economic resources are confined to a 7 km section in the vicinity of the Macraes township. The shear zone, which typically dips at a low angle (~20 o ) to the NE, is bounded by an upper hanging wall shear and a lower footwall fault. Mineralisation occurs along the hangingwall of the shear zone as well as in low angle concordant shears and stockworks. Ore types include graphitic cataclasites with variable amounts of quartz veining, ælode schistsÆ and quartz-vein stockworks. Rehabilitation at the mine has focused on creating an environmentally benign site dominated by pasture to allow continuation of the traditional pre-mine farming economy. Changing regional economics, continued urbanisation and a reduction in traditional employment opportunities has seen a rethink in the long-term rehabilitation outcomes. The community has recognised that the rehabilitated site will provide the basis of a viable tourism venture and the creation of a Heritage and Art Park (working title æGolden Point ParkÆ) is the culmination of that process.

Jan 1, 2002

By M Scamardella

The CSA Mine is located at Cobar, New South Wales, where it was in continuous operation from 1966 to the time it went into receivership on 29 January 1998. When it closed it was under the ownership of Golden Shamrock. Glencore International, in conjunction with Mt Lyell Mining, undertook a due diligence study to determine the feasibility to re-open the mine. This envisaged operating CSA Mine as a low-cost, copper concentrate producer under the direction of Cobar Management Pty Ltd (CMPL). The new workforce would consist of contractor trades people in operating functions under the co-ordination of CMPL staff, both on the surface and underground. This was the key to establishing the new culture in the workforce. The orebodies at CSA Mine are steeply dipping with copper-lead-zinc mineralisation in zones of strong alterations in a fine-grained siltstone host sequence. The predominant economic minerals are chalcopyrite, sphalerite and galena. The major gauge minerals are pyrrhotite, pyrite, chlorite, sericite and quartz. Ore for the project is being developed and mined from two high grade copper lenses within the QTS North system. Chalcopyrite occurs in two forms. The first consists of coarse chalcopyrite grains in association with pyrrhotite or pyrite. The second form consists of chalcopyrite grains intergrown with pyrrhotite grains. This form of chalcopyrite is quite rare. It allows electrochemical interactions between grains, resulting in rapid oxidation of the chalcopyrite surface. Physically this ore looks like, and has been mistaken for æpeacock oreÆ, ie bornite, but is infact oxidised chalcopyrite.

Jan 1, 2000

Computerisation of mine planning activities, specifically in the areas of geology, design and surveying, has been in progress for a number of years in underground metalliferous mines. The combined capabilities of hardware and software have only recently reached the levels necessary to fully support integrated mine planning computer systems in a graphical three dimensional environment. Despite the apparent capabilities of systems now on the market, many sites retain significant parts of their older paper based systems, and employ a mix of two or more software packages. This paper examines what underground metalliferous sites are doing in this area in Australia, and discusses the factors which are inhibiting full implementation of fully integrated computerised systems. Future directions for further developments in the field are also briefly discussed.

Jan 1, 1995

The Newmont Waihi Operations are centred on the Martha mine at Waihi, New Zealand. The mine has produced over 6.6 million ounces of gold from both openpit and underground sources since operations began in 1878. The current open pit operations commenced in 1988 and in the year to 30 June 2002 produced 129,790 ounces of gold at a cash cost of USD122 per ounce. This paper provides an overview of current operations and future directions.

Jan 1, 2002

By L M. Zhang, T H. Xu, J Zhao

Blasting is one of the most commonly used strategies for excavation in civil and mining engineering. Yet blasting can also bring along such undesirable effects as ground vibrations and soil disturbance. Numerical analysis is a powerful tool for estimating the effects of blasting and improving blasting design. In this research, a constitutive model for sand is proposed for the numerical analysis of blast-induced ground motions and wave propagation in soil mass. In the model, three model surfaces, ie the critical surface, the dilatancy surface and the bounding surface, are defined following the bounding surface hypoplasticity framework. The strain rate is included explicitly into the model formulations so that the proposed model is valid under high strain rate loadings caused by blast-induced vibrations. The performance of the proposed model is validated by the simulation of drained triaxial compression tests conducted on a crushed coral sand under different strain rates.CITATION:Xu, T H, Zhang, L M and Zhao, J, 2014. A bounding surface model for sand subjected to blast-induced vibrations, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 201–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014