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By M Littlefair, D Gribble, R Rounsley, I Te

Low-density explosives (LDE) have applications where the explosive properties of ANFO are not well matched to the rock. In particular, rocks that are of low strength and/or well fragmented in situ. Dyno Nobel Asia Pacific (DNAP) has developed a new LDE, BlastLiteTM, which can be used as a cost-effective replacement for ANFO with excellent detonation characteristics. The product is based on ANFO with the addition of a bulking agent. The key to the product lies in the ability of the bulking agent to form a homogeneous blend with ANFO without the need for any emulsion matrix to bind the product together. This results in an LDE of low cost and high weight strength compared to existing commercial LDE products. The product has been trialled extensively and has proven to provide results that are equivalent to, and often better than, ANFO with reduced powder factors. This paper details the laboratory development and results of field trials for DNAPÆs LDE solution: BlastLite.

Jan 1, 2004

Financial theory often takes some time to penetrate industry and when it does it can result in a paradigm shift in valuations and mental models. The Black Scholes option valuation was first published in 1973, although the authors were only awarded a Nobel Prize in 1997. The valuation of real options has been applied to the oil and gas industry for some time, however it has only recently been more widely applied to the non-oil, mineral resource sector. The use of real option valuation (ROV) for the valuation of marginal and short mine life resource projects is a more useful valuation tool than the conventional DCF, NPV valuation tool. The application of ROV has major implications for corporate strategy. It generally favours equity over debt funding and non-hedging over hedging. A retrospective assessment of the successful development of the Lennard Shelf Operations demonstrates the concepts of implementing real options and the value destruction of limiting operational flexibility through debt and hedging activities.

Jan 1, 2003

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

By Bassett N

The Eneabba deposit, located 280 km north of Perth, Western Australia, and 30 km inland (Fig. 1) is one of the most recently developed deposits of mineral sands in the world. The area has been in production since 1974, while the Associated Minerals Consolidated Limited (AMA) operation commenced production in 1976. Total ore reserves of close to 400 million tonnes contain about 40 million tonnes of heavy minerals (proved and probable).

Jan 1, 1979

Following GyÆs earlier proposals for the use of StudentÆs t-test, a simplified, effective method and philosophy are proposed to test for maximum tolerable bias in data sets as well as in sampling devices. The philosophy of testing is particularly emphasised to derive important practical implications in terms of decision-making and risk control. Conclusions are offered which should equally matter to manufacturers and users of sampling equipment.

Jan 1, 2005

The Torington Lodes.This paper describes investigations into mineralogical, petrological and structural associations of cassiterite in occurrences of economic value. The work was carried out in three mines, during a number of years, in the hope that the, data collected might be helpfulin the search for occurrences of cassiterite in stanniferous zones and reduce unproductive exploratory work. Tin-bearing lodes at Torington, in the New England district, New South Wales, have been worked since 1880, and the locality is the most important centre of lode tin occurrence in the, State. The township of Torington is 18 miles westerly from Deepwater, a station on the Great Northern Railway, 446 miles from Sydney.The tinfield forms part of the Mole Tableland, which has an altitude between 3,000 ft. and 4,000 ft. above sea level. The country rock, in which the stanniferous lodes occur, is granite of Permian age, which has been intruded into Carboniferous claystone. An inlierof claystone is exposed to the west of the stanniferous area, 'and in it, close to' its contact with the enclosing granite, are occurrences of wolfram and bismuth. These minerals, together with chalcopyrite, pyrite, arsenopyrite, zinc blende, galena and molybdenite, in very small quantity, are associated with cassiterite in lodes traversing the granite, particularly near the claystone, but decrease in amount with distance from the contact. Their occurrence is sporadic and usually causes no trouble in dressing the cassiterite concentrate, the final product containing less than 1% of total penalisable impurity. In Curnow's mine, pyrite, galena and molybdenite have been observed at 700 ft. from surface.The granite is of the biotite type and its structure may be divided into four groups, or classifications, arising from segregation processes during cooling and consolidation. The four classes, in order of extent of distribution, are:1. Granite of normal type, in which the constituent quartz felspar and mica, have a particle size approximately 14, in.2. Porphyritic granite, in which the felspar particles are from % in. to lin. in size, that of the quartz and mica approximately % in.3. A fine-grained granite, in which the particles of all constituent minerals are % in. or less in size;4. A rock of highly siliceous ground mass containing very small particles of felspar and almost negligible biotite.Type 1 is the general type of granite in all mines of the field; types 2 and 3 may occur as large masses, or all three classes may merge rapidly one into the other, and all be disclosed in 20 ft. of driving. Usually, however, the segregations are massive, but are not associated with any special horizon. For instance, a mass of porphyiiticgranite extends from surface to a depth of 440 ft., for a distance of 350 ft. south from the New England main shaft. The upper levels of Curnow's mine, 14" mile south-east, are in normal granite, but a restricted mass 'of porphyritic granite occurred between Nos. 5 and 6 levels, or 400-500 ft. below the collar of the shaft...

Jan 1, 1950

By De Broglio R

The Mae Moh coal deposit was discovered some 60 years ago by villagers who noticed spontaneous combustion of coal outcrops. The first production began in the 1950's to fuel a fertilizer plant and a 12.5MW power station. During the period 1976 to 1979, three 75MW power station units were constructed on site. These have a total daily coal consumption of some 5000 tonnes and are served by a stockyard of approximately 60 000 tonnes total capacity. Stacked coal is reclaimed by means of a front end loader onto reclaim conveyors. During the years 1983 to 1986 four 150MW power station units were constructed east of the eastern seam subcrop, sons 2 km from the original power station complex. These have a daily coal consumption of nearly 12000 tonnes and are served by a stockyard of total capacity 270000 tonnes, equipped with two stackers and two bucket-wheel reclaimers for a totally mechanised system.

Jan 1, 1986

By Briggs D

Comparing the results of a plant trial by averaging performance measures collected during the trial with measures collected before and after the trial is often quite subjective because of the impact of natural variation on the process. This is

Jan 1, 1997

By D Joshi, J Rostami, M Karakus, A Eustes

The first target of mining activities on the surface of the moon is to find and extract water from the icy regolith on the moon. A test drilling unit was designed and fabricated under a NASA Early Stage Innovation (ESI) grant. A high-frequency data acquisition system was used to record drilling responses at 1000 Hz. Parameters like weight on bit (WOB), torque, rev/min, rate of penetration (ROP), mechanical specific energy (MSE), field penetration index (FPI), and the uniaxial compressive strength (UCS) were recorded for 40 boreholes in the analog samples made of regolith simulant and specialised cement. Development of the AI system and machine learning (ML) algorithms for analysis of data to evaluate strength and hence water content of icy regolith required a large data set. In this case, the data set comprising of more than one billion data points recorded while drilling into various analogue samples and cryogenic lunar formations to optimise power consumption and make bit wear adjustment during drilling operations. The tests were also repeated in the samples of icy regolith at various water content at -190C to verify the ability of the algorithms to analyse the data and to estimate the strength of the frozen formation and hence water content. The paper will discuss the objectives and methodologies used in the project and reviews the testing program and the machine learning (ML) algorithms ability to identify various formations along the exploration boreholes.

Sep 1, 2024

As an indication of the overall quality for the three periods the expected run of mine ashes are given. Operating Period R.O.M. Quality Years 1 - 4 22.0% Ash (db) Years 5 - 14 18.8% Ash (db) Years 15 - 20 17.3% Ash (db) The size distribution of the coal was found to be generally as predicted in the 1980 study. However the ash, particularly in the smaller fractions, was found to be higher due to the previously mentioned friable nature of contaminant material. Following evaluation of this additional information, the proposed washery design was reconsidered. Three basic process schemes were examined. 1. A jig with two-stage heavy medium cyclones and spirals for treatment of three different size ranges. 2. A heavy medium vessel, two-stage heavy medium cyclones and spirals for the different size fractions. 3. A jig for initial treatment of the total feed (that is all sizes) with single-stage heavy medium cyclones and spirals for rewashing of the intermediate and smaller size Fractions.

Jan 1, 1986

By Brockway DJ, Holmes RJ

A natural gamma-ray gauge has been devel- oped for discriminating overburden and inter- seam sediment from low ash coal located on a moving conveyor belt. It is based on the difference in natural radioactivity of the sediment and overburden compared with the low ash coal, which is detected with a highly ef- ficient "Polyscin" NaI(T1) gamma-ray detector located underneath the conveyor. Gauges have been successfully installed on the bucket wheel boom of the two coal dredgers at the Loy Yang Open Cut. They are used to warn dredger operators that they are digging overburden or sediment and that action is required to avoid the sediment or divert it to the waste dump rather than send it to the coal bunkers at the power station.

Jan 1, 1987

By Sneyd R. J, Walton M. C

In early 1987 Minproc acquired a license from the inventor to engineer and construct acid plants incorporating the Fattinger technology. The process offers a simple and reliable method of producing sulphuric acid from metallurgical off gases at significantly lower capital and operating costs than the more familiar contact process. The process also offers the simultaneous production of nitric acid, if the NOx content of the off gases is high enough. A development of this latter process has other applications within the minerals industry, particularly in conjunction with refractory gold ore preoxidation.

Jan 1, 1989

By S Lowjun, I Verster, C A. Thomas, E Forbes, K Runge, G V. Franks

Fine (<20 µm) valuable mineral particles are difficult to recover in conventional flotation circuits. (Trahar and Warren, 1976; Jameson, Nguyen and Ata, 2007; Kohmuench et al, 2018). This leads to a loss of valuable fine mineral particles to tailings. Recovering these particles would be of economic benefit. Novel reagents, including temperature responsive polymers, for example, are being developed to improve recovery of fine valuable mineral particles by froth flotation (Ng et al, 2018a, 2018b). The approach involves selectively aggregating the valuable fine particles and making these aggregates hydrophobic, resulting in hydrophobic aggregates of appropriate size (in order of 100 microns) being amenable to recovery by froth flotation. The polymers developed have been produced at laboratory scale but not a full scale yet. The exact cost of producing such novel polymers is currently unknown, but they are likely to be more expensive than conventional reagents.

Aug 24, 2022

The Lane Cove Tunnel (LCT) is an important infrastructure link in New South Wales (NSW) and runs from the end of the Gore Hill Freeway at Artarmon at its eastern extremity, to the end of the M2 at North Ryde at its western extremity.&nbsp; The LCT is 3.6 km long and generally consists of twin two/three lane unidirectional tunnels running largely under Epping Road from just east of Mowbray Road, west to the western end of the Gore Hill Freeway. The tunnel opened in early 2007. The presentation will provide a summary of the traffic and emission modelling performed for selected representative surface road sections in the vicinity of the Lane Cove Tunnel. An assessment of the predicted impact of vehicle emissions on ambient air quality in the corridor as a result of changed traffic conditions due to the tunnel opening will be presented. The traffic modelling and emission calculations were undertaken for the following two scenarios: Year 2006 û Lane Cove Tunnel no-build option, and Year 2006 û Lane Cove Tunnel build option. Vehicle emission calculations for the four main pollutants from vehicles: CO, VOC, NOx and PM10 on the surface roads in the vicinity of the Lane Cove Tunnel were performed using the predicted daily traffic for the two cases (no-build and build). The analyses indicated that the vehicle emissions for all pollutants are expected to significantly reduce in the corridor with the building of the Lane Cove Tunnel, including the areas in the vicinity of all tunnel portals, when compared to vehicle emissions for the no-build case.&nbsp; As a result of the decreased vehicle emissions on the surface roads, the study concluded that the actual ambient air quality is expected to improve in the corridor including the tunnel portal areas after the Lane Cove Tunnel opening.

Jan 1, 2008

The addition of cement to underground backfill at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited, Broken Hill commenced in 1967. A deterioration in metallurgical performance at each concentrator occurred as a result, with increased loss of lead and zinc to residues. Investigations to determine the reasons for this problem and methods to counteract it have been undertaken. This paper outlines the effects of cement on lead-zinc beneficiation at Broken Hill and presents an interim report on attempts to overcome the metallurgical deterioration.

Jan 1, 1971

The process of evaluating orebodies at the feasibility study stage is extremely important. In recent times many groups have indicated that they would like ore reserve estimation to be numeric and objective. Whilst sampling, geological, mining and mathematical principles may be used to analyse the data, all ore reserve methods require the use of experience factors and as such are value j ddgment statements.

Jan 1, 1990

By R Wei, Y Peng

With the depletion of high-quality ores, the efficiency of extracting difficult gold ores through flotation and leaching becomes very important in the mining industry. Iron contaminants, sulfide and carbonaceous coatings on the surface of gold and gold bearing minerals significantly hinder the recovery of gold during gold processing. As the surface of gold minerals is easily contaminated, coatings of iron oxides and iron hydroxides originated from the grinding process and oxidation of iron sulfides will cause a retarding effect on both gold flotation and leaching.To mitigate the processing issues caused by undesirable surface coatings on gold minerals, a new technology in treating surface coatings of iron contaminants has been developed. The pulp potential and pH of the slurry are altered to allow dissolution of surface coatings which are further excluded by the use of complexing reagents. The current work shows that iron contaminants can be removed from the surfaces of gold through Eh-pH adjustment and chelation which result in significantly improved gold flotation response. The addition of complexants aids the formation of iron chelates to prevent the iron species in the solution from forming iron oxide and iron hydroxide in the flotation conditions.CITATION:Wei, R and Peng, Y, 2014. Mitigating the effect of surface coatings on gold processing, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 187–192 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By W F. Bawden, J T. Paynter

This investigation involves laboratory testing and stability analysis of paste fill at the Golden Giant Mine. Site-cast samples are tested in unconfined, confined, and consolidated-undrained triaxial compression. Pore pressures during shear and consolidation characteristics are measured to determine both drained and undrained shear strength parameters and assess the potential for undrained loading. Liquefaction potential is also considered. A limit equilibrium solution is used to obtain factors of safety against failure of the fill during mining of adjacent stopes.

Jan 1, 1998

Developments in furnace construction and design have been very rapid in recent years. Larger furnaces operating at high top pressures with much improved burdens are giving extremely high production rates. Modern scientific techniques and the use of computer control are contributing to these Rates.

Jan 1, 1972

By K Steamy, D Lesmana, K Yulia

Effective selective mining relies heavily on high quality geological data and assay data. Such assay data is dependent on effective sampling protocols, sample preparation techniques, assaying practices and well founded quality assurance/quality control (QA/QC) procedures. This paper describes recent developments in grade control sampling at PT Nusa Halmahera Minerals high-grade Kencana gold mine at Gosowong Indonesia and presents a case study in identifying, minimising and monitoring random and systematic sampling error including the use of duplicate sampling and the Thompson Howarth technique for quantifying random sampling error.

Jan 1, 2009