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By C E. Davies

At present the source of virgin iron for steel produced in New Zealand is titanomagnetite extracted from titaniferous beachsands. Some of these beachsand deposits contain extractable quantities of ilmenite as well as titanomagnetite and both minerals represent challenging sources of vanadium and titanium products in addition to iron. This study looks at some theoretical aspects of smelting these ores directly with coal rather than with electric power, and takes into consideration the properties of the raw materials, the thermodynamics of possible process routes and the background of the economics involved.

Jan 1, 1980

By Creelman C. A

With the technique and data obtained in using the blast hole diamond drill for "Removal of Horizontal Level Pillar by means of Blast Hole diamond drilling at New Occidental Gold Mines N.L.," as described in Proceedings No. 133 of 1944, and a series of experiments using the blast hole diamond drill for stoping at New Occidental and New Cobar Mines over the past two years, a benching method of stoping has been developed using 2 inch coring diamond drill bits, resulting in efficient and economical ore extraction in these large ore bodies.During the experimental stages the standard H-inch blast hole was used, but the deflection of the holes, when using this solid bit, either decreased or increased the burden of the hole when it became necessary to drill holes deeper than 45 feet.It was found that after blasting vertical holes deeper than 45 feet, the ore did not break satisfactorily over the full length of the hole; on one occasion as much as 30 feet of bench was left at the bottom of the face, which had to be subsequently re-bored andblasted.As this defect was also noticeable to some extent even when the holes did not deflect, it was then obvious that the explosive had become less sensitive in the lower section of the hole. This was probably brought about by pressure being built up ahead of the detonation wave in H-inch hole, resulting in desensitization of the explosive.Another series of experiments were carried out, using 2-inch solid bits, which enabled a much greater burden on the holes, and the use of primacord for the full length of the hole.This gave satisfactory results regarding breaking and fragmentation, but was uneconomic owing to the excessive consumption of diamonds, and the slow rate of drilling.Further experiments were then carried out using 2-inch coring bits, (Fig. 1) which allowed holes of 90-feet to be bored with little deflection, and proved to be entirely satisfactory as to cost and speed of drilling.

Jan 1, 1945

The use of scrapers in mining and earthmoving operations is not new, in fact they are one of the earliest methods of bulk earthmoving. A single machine which can load, haul, and dump material with a minimum of ancilliary support is a highly productive and cost-efficient method of earthmoving. In recent times scrapers have been unpopular due to perceived problems and operational limitations, but the last couple of years have seen a resurgence in the use of scrapers in the Bowen Basin as a primary prestripping tool. The main operational limitation of scrapers is the economic operating range. maximum productivity and lowest cost per bcm is achieved on short leads, as the lead distance increases the cost per bcm quickly reaches and then overtakes that of an truck-excavator fleet. The geometry of a ætraditionalÆ coal mine does not readily allow short leads for prestrip fleets due to the nature of dragline stripping operations. The strip arrangement means that material has to be taken around the end of the pit, meaning a longer haul distance than the actual point-to-point distance between load and dump. This can be alleviated by using pit bridges, however these can cause spoil problems for draglines if not properly planned and have been avoided by many mines. Due to the economic haul distance limitation of scrapers, truck-excavator fleets have become the normal method utilised. Currently more geologically complex mines are opening up, which do not allow traditional down-dip strip mining to occur. Cross-dip mining methods allow for short leads between prestrip loading and dumping areas, hence scrapers and bulk doze are realistic alternatives to a truck-excavator fleet in the prestrip environment. Keeping the lead distance to a minimum a fleet of 657Æs can move material at a very low cost. The other main operational limitation of scrapers is the type of material that can be economically excavated. Hard material can lead to damage to the bowl, free-flowing sand will not readily stay in the bowl leading to reduced load factors. Ripping the material with a dozer prior to excavating can lead to improved loading time, and greatly reduced GET consumption. When considering scrapers for prestrip operations a number of things must be considered: is the lead distance within the economic haul distance? should twin power (push-pull) or single power (dozer pushed) scrapers be used? do I need to rip, what should I rip with? what ancilliary support is required? is there another system already available on-site which is currently under utilised? This paper considers the parameters under which large twin power scrapers are the most effective way of undertaking prestrip operations.

Jan 1, 2003

At the Orieco mine quartz veins carrying sulphides were localized in parts of an extensive fault zone in the Mathinna Beds during late Middle Palaeozoic mineralization.These deposits were subsequently exposed, and oxidation of the sulphides by percolating groundwaters resulted in the formation of gossans at the surface, and replacement close to the permanent water table of the more soluble sulphides by copper sulphides (chalcocite, coveIlite). A restricted zone containing copper oxides (cuprite, tenorite), copper carbonates (malachite, azurite), iron arsenates (scorodite, pharmacosiderite) and possibly rare copper sulphates occurred above the water table.The renewed oxidation of these deposits following mine development has been facilitated by the ready circulation of air and water combined with the formation of large free surfaces ideal for evaporation of aqueous solutions. Under these new conditions of high initial sulphate concentration, low pH, and relatively high Eh, the previously formed mineral assemblage is unstable and numerous Cu (Fe,Zn)-sulphates and Fe (Cu,Pb)-arsenates are presently forming in fractures in the fault zone and on the adit and stope surfaces for some considerable distance from the Sulphide-rich ore shoots. The observed spatial sequence of the major sulphates with respect to the sulphide-rich zones (Le. chalcanthite-antleritebrochantite and langite) is consistent with decreasing sulphate concentration and increasing pH away from the oxidizing sulphides.

Jan 1, 1970

By A D. Campbell, G R. Power

The objective of the draw strategy in a caving mine is to maximise economic return by minimising waste dilution3 and maximising ore recovery4. The draw strategy must also include suitable controls for air blast and mud rush hazards and is highly constrained until continuous cave propagation has been achieved. This paper details a three-year project at the Ernest Henry Mine (EHM), which used cave flow simulation software to develop a draw strategy that increased the mine value by 32 per cent.Dilution and ore loss can be significant in sublevel cave (SLC) operations and result in poor recovery and considerable economic losses. To minimise dilution and ore loss, cellular automata software was used to simulate cave flow over the mine life. The optimisation project required mining footprints for various cut-off grades to be developed. Draw strategies for each mine footprint were then generated using a range of shut-off grades. Economic assessment of each scenario was then conducted to determine the mine footprint and corresponding draw strategy that generated the highest NPV (net present value). The iterative simulation process was improved by developing automated software functions in the flow modelling software to reduce time taken to generate and assess life-of-mine (LOM) draw strategy scenarios.In addition to improving the NPV of the mine, the optimisation project also enabled a decrease in the mine cut-off grade which increased the ore reserve and extended the mine life. Overall, an iterative process of mine planning, cave simulation, economic evaluation and geotechnical analysis was used to significantly increase the economic return of the SLC whilst ensuring caving risks were controlled to an acceptable level.CITATION:Campbell, A D and Power, G R, 2016. Increasing net present value by a third at an operating sublevel cave mine using draw strategy optimisation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 167–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Hannan J. C

In New South Wales, development applications for major coal mining proposals are determined by the Minister for Planning and Environment and applications for mining leases and other mineral titles are dealt with by the Minister for Mineral Resources. The environmental conditions placed on the development consent, the coal mining lease and the approvals and licences under the pollution control legislation, amount to a substantial component of any new project's planning and commissioning considerations.An outline is presented of the framework within which various approvals are granted and conditions for environmental management are imposed upon mining projects. The principles and concerns, as perceived by the regulatory authorities, on which the majority of approval conditions are based are also outlined.No attempt has been made to analyse the extent to which these principles or standards are achieved in practice, nor to discuss the degree to which some of the conditions are achievable with the current status of technology and economics in the coal industry.

Jan 1, 1987

Metana Minerals commenced life in 1970 and graduated to a mining company in 1981 with the opening of a small alluvial tin-tantalite mine at Wodgina (W.A.) The present board of directors assumed control of the company in 1978 and established the exploration and development philosophies that have guided the company's expansion to its present status as an emerging diversified miner. An ability and willingness to raise equity capital when required has been a feature of the company. Company activities include exploration for gold, diamonds, heavy mineral sands, polymetallic (base and precious metals) deposits, strategic minerals, rare earths, oil and gas in a geographical distribution covering the entire Australian mainland Metana owns and/or operates four gold mines (Reedy, Mt Magnet, Youanmi and Howley) and at the time of writing is developing a fifth gold mine - its first underground mine - at Rothsay. In contrast to many similar or larger sized companies, Metana undertakes most activities itself rather than through the use of consultants or contractors. In-house services include: analytical and metallurgical laboratories, plant engineering design and construction, drilling and mining (earthmoving) Metana Minerals has established an enviable reputation for technical excellence and this expertise has placed the company in a sound position to continue its growth pattern into the future. This growth will be achieved through a combination of low cost and successful exploration and acquisition of suitable mines either directly or through corporate activity.

Jan 1, 1989

Drilling and blasting are an essential part of most mining operations, and are commonly major operating cost centres. The effectiveness of blasting can have a significant influence on all subsequent activities, and hence overall operating costs. Drilling and blasting systems must be compatible with the overall mining method, to minimise total costs and ensure operational efficiency. Selection of suitable equipment and techniques requires an understanding of the total operation, plus current skills in specialised technologies. This paper examines the contribution of drilling and blasting to total costs, including the balance between capital and operating costs. The use of computer modelling is discussed, to demonstrate how blast performance and costs can be predicted and alternatives analysed. Case studies illustrate how cost savings can be made in operating mines, and alternative systems evaluated to optimise new projects.

Jan 1, 1990

By I Lamb

Past experience of ground settlement and groundwater monitoring for tunnelling projects in Melbourne has provided an appreciation of the value and importance to owners of establishing a broad baseline monitoring program of the ground surface movements and groundwater movements well in advance of the commencement of any excavation and tunnelling activities. For the Northern Sewerage Project (NSP) tunnels in the northern suburbs of Melbourne, a baseline monitoring network of ground settlement points and groundwater wells was established in early 2006, 18 months prior to the commencement of project construction, and has continued throughout the tunnelling and project construction activities. This baseline monitoring network provides insights into the superposition and interpretation of both tunnelling and non-tunnelling effects, such as seasonal effects, which result in ground settlement.In the case of the NSP the baseline monitoring and construction phase excavations coincided with several years of drought. The reduced rainfall developed overall downward settlement trends project wide that could easily be mistaken at the local site level to be construction effects if the baseline monitoring was not available to show otherwise. There are lessons to be learned from the NSP experience for tunnel projects where there are variable surface soil types and where project-specific settlement criteria are to be established for the protection of property prior to construction.This paper presents examples of the baseline monitoring, how the tunnelling-specific settlement was identified and determined, and what this means in terms of how settlement criteria should be established and set for project consenting and in the construction contract documents.

Mar 8, 2011

By M Hourn, D Turner, P Voigt, D Mallah

The GPM Gold Project is located in Armenia, and consists of an open cut mine at Zod, near the Azerbaijan border, and a CIL processing plant at Ararat near the Turkish border. Mining at Zod commenced in 1976, and focused on near surface oxide ores, which overlay deeper refractory sulphides. Historical mining has now almost depleted the oxide ores, and the sulphide content of ore delivered to the processing plant at Ararat is increasing. Gold and silver recoveries through the Ararat plant were declining steadily.GeoProMining, the owners of the project, have expanded the Ararat facility to deal with the increasing sulphide content in the ore. In 2014, GeoProMining refurbished an existing concentrator on site to recover a sulphide concentrate from the ore, and have constructed an Albion ProcessTM plant to oxidize the refractory concentrate. Glencore Technology (GT) provided the Albion ProcessTM plant as a technology package.In July 2014, the progress of the GPM Gold Project Albion ProcessTM Plant was reported (Hourn, Voigt and Turner, 2014). At the time of writing, the construction of the plant was nearly complete. This paper presents an update of project progress, covering commissioning and ramp up of the GPM Gold Project.The commissioning phase occurred over June to August 2014, which included an M3,000 IsaMillTM fine grinding plant, a 6 tph limestone milling plant, a 60 tpd vacuum pressure swing adsorption oxygen plant, a 10 m residue thickener and a 12 tph Albion ProcessTM oxidative leach plant. Since commissioning was completed, ramp up occurred over the following three months with downstream gold recoveries from cyanide leaching reaching over 98%.CITATION:Voigt, P, Hourn, M, Mallah, D and Turner, D, 2015. Commissioning and ramp-up of the Albion Process at the GPM Gold Project, in Proceedings MetPlant 2015, pp 207–219 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

Winzes are usually sunk 9 ft. 6 in. long by 6 ft. 0 in. wide and are divided into two compartments, 4 ft. 0 in. by 5 ft. 0 in. inside the timbers. The general practice is to sink the winze to a depth of from 9 to 12 ft., put in bearers and three or four rings of timber, and then erect a sinking headframe before continuing sinking operations.GENERALThe main feature governing the design of the headframe was that all parts could be transported on timber trolleys in No. 2 Shaft. Except for some minor details the structural members consist of steam pipe. Joints are sections of steam pipe welded to one member and into which the other member fits and is held in place by a 1-in. bolt. The headframe consists essentially of two bedpieces to carry the winch and to form a seat for the four legs. The legs support the sheave bearers, the tipping door and the brace.Except during tipping operations the door is in a nearly vertical position. For tipping it is lowered to an inclined position and a hook suspended from one of the bracing members of the headframe is attached to a "D" welded to the bottom of the kibble. This causes the kibble to tip when it is lowered on to the tipping door. The capacity of the kibble is 4 cubic feet.THE HEADFRAMEThe dimensions of the headframe are:Height to top of sheave .. .. 14 ft. 10 in.Distance centre to centre of legs 4 ft. 4 in.Length of bedpieces .. .. .. .. 8 ft. 9 in.The weight is approximately 2,000 lb., the tipping door and bedpieces being the heaviest members. They weigh 240 lb. and 170 lb. respectively.One compartment of the winze is decked over, and the bedpieces, which are 8 ft. 9 in. lengths of 6 in. pipe with three short lengths of plate welded to the underside, are placed over the sinking compartment, either transversely or parallel to the winze. Three 3 inch pipes act as spreaders between them.Welded to the top of each bedpiece is a 6-in. by iHn. plate 3 ft. 0 in. long with four 4-in. by 1.5-in. slots cut longitudinally at 10 in. centres. Two 10 in. by 4-in. timbers are bolted to these plates, the distance between them being adjusted to suit the holes in the winch bedplate, which is bolted to the 10-in. by 4-in. timbers.Two short lengths of 3 in. pipe are welded to each bedpiece at 4 ft. 4 in. centres. These form the seats for the legs of the headframe, which are...

Jan 1, 1941

In undertaking to write a few notes on practical mining in Bendigo, the great quartz mining centre of Victoria, which just now is celebrating its fiftieth anniversary of gold mining, satisfaction must be expressed which is, no doubt, shared by all mining men and inyestors, that Bendigo has not lagged behind other Australian mining districts in the evolution of mining from its crude state, subsequent to the discovery of gold in 185 to its present more perfect state; and though it may be said that it has not yet reached the high pinnacle of perfection towards which advanced science and change of conditions may yet lead it in the course of future progress, yet, what has already been done in this respect, the adoption of the most approved methods appliances and modern machinery, tending towards greater and still greater efficiency, facility, and economy in our mining industry, must be accepted as a guarantee that in tne future as well as in the past, progress in our means of developing our mining resources will ever remain our watchword, by means of which future difficulties will be overcome as well as they have been removed in the past.The adoption of this principal, combined with a study of rigid economy, has raised gold mining here, as well as in other places, from a state of speculation, and sometimes wild speculation, to the status of a solid, stable industry, the strong supportand backbone of the country in which it flourishes. Two of the principal factors which have been to a great extent instrumental in bringing about this satisfactory state, must be specially mentioned.

Jan 1, 1902

By K C. Runge, E Tabosa, A Jankovic

Flotation recovery in geometallurgical modelling is usually predicted based on relationships developed from batch flotation testing of different ore types. These batch flotation tests are usually performed at a constant set of operating conditions and at a fixed feed grind size P80. Usually the laboratory feed grind P80 is that which is expected to be produced in the full-scale flotation circuit for that particular ore type.Flotation recovery will be a strong function of the valuable mineral particle size distribution, with lower recovery of ultra-fines due to poor flotation kinetics, optimum recovery for the intermediate sized particles and lower recovery for the coarser particles due to poorer liberation of this fraction. This valuable mineral particle size distribution is not characterised by the solids P80 parameter alone. The proportion of material in each class will also be a function of the slope of the size distribution and the degree of preferential grinding of the valuable mineral in comparison to the total mass of the ore.This paper will demonstrate (through example) how these other size distribution parameters can change with a change in grinding technology, the size and operating conditions used in a grinding unit and the characteristics of the classification technology used in conjunction with the grinding unit. Case studies will be presented that demonstrate how this can result in these parameters being very different in laboratory testing to that produced in the full-scale comminution circuit. A rule of thumb that laboratory rod milling rather than ball milling produces a size distribution most similar to that of the full-scale grinding circuit will be challenged. These differences can result in a significant change in flotation recovery. It is therefore important to consider these parameters when developing a laboratory geometallurgical program, to enable more accurate prediction of the flotation recoveries that will be achieved in the full-scale process.CITATION:Runge, K C, Tabosa, E and Jankovic, A, 2013. Particle size distribution effects that should be considered when performing flotation geometallurgical testing, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 335-344 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

Production scheduling of open pit mining is a key area as it deals with the management of operating cash flows of mining companies. The efficiency of long-term schedules is usually assessed with economic criteria such as net present value (NPV), discounted cash flow rate of return (DCFROR) and payback period, which are not sufficient on their own for revealing the complex picture of the decision-making process.This paper offers a thorough analysis of the most important contemporary criteria of long-term production scheduling, as way to provide the mining practice with a new approach to the decision-making process. The list of criteria includes technological, economic and probabilistic ones. A detailed case study is provided aiming to illustrate the applicability of the criteria for comparing the scheduling approaches regarding the economic interests of a mineÆs owner and contractor. The results obtained can be used for revealing new trends in the current methodology of open-pit production scheduling optimisations.

Sep 26, 2011

By M P. Simpson

Forty one whole rock samples from the Gold Cross low-sulfidation epithermal Au-Ag deposit have d18O values that range from 4.4 to 9.3 per mil, with an average value of 7.0 per mil. Unaltered and weakly altered rocks have d18O values greater than eight per mil, and the orebody is surrounded by samples that are depleted in 18O. A strongly silicified sample adjacent to the Empire Vein System has a d18O value of 9.0 per mil, similar to previously reported analyses of vein quartz (7.0 to 11.7ë, average 9.4ë). This suggests that, in detail, Golden Cross may have a zone of 18O-enriched wall rocks in the core of the deposit, adjacent to the main underground veins. Although some workers have suggested that stable isotope geochemistry may provide useful information for epithermal mineral deposit exploration, at Golden Cross this is not the case. Alteration minerals, major elements and trace elements all define larger, less ambiguous halos than the zone of 18O-depleted wall rocks.

Jan 1, 2001

By T Hughes

Upward pressure on all mining operations is coming from the triple bottom line. To some extent this is being offset by the rise in mineral prices, but this may or may not continue. The other serious issue facing all companies is the replacement of economic reserves as exploration levels over the past decade continued to decline in line with falling mineral prices. In order to underpin the sustainability of the mining industry it is necessary to continue to reduce cost, reduce the mine environmental footprint, whilst increasing community benefit. At the same time it is imperative that we increase the economic reserves. The highest risk is in adding new mineral discoveries as the strike rate for economic discovery decreases. Gekko Systems Pty Ltd recognises that the most simple and risk averse route to increasing economic reserves is to reduce cut-off grade in the mine, thereby bringing formerly uneconomic reserves into the economic category. We have been developing a new process flow sheet which embodies the triple bottom line and the issue of economic replacement of reserves. This paper describes this flow sheet and presents four examples where this concept is/can be applied to bring about triple bottom line benefits. Sustainability can only be assured if we are the ones in control of our environment, costs and reserves.

Jan 1, 2007

The effect of conditioning energy input on the metallurgical results of an emulsion flotation process has beenattributed by previous authors to a detergency process.This paper shows that such a process does not explain the data and that an attrition mechanism is more appropriate.

Jan 1, 1970

By McKenzie P

The techniques of geological control developed by the Coal Geology Sections of the Broken Hill Proprietary Company Limited and Australian Iron and Steel Proprietary Limited in providing geological service in the coilieries operated by these associated companies cover the provision of geological control for both planning and production in each of which the significance of geology has in the past been only poorly appreciated by the coal mining industry.While the adoption of similar techniques is well within the capacity of major companies there is considerable scope for the development of government geological services providing specialized assistance of this nature for smaller scale producers.INTRODUCTIONThe coal mining industry in Australia can instance many notable mistakes caused by failure to obtain sufficient geological information or by incorrect interpretation of available geological evidence both before the commencement of mining and during the progress of operations. Substantial development undertaken in, areas with insufficient or inferior coal reserves, difficult mining conditions caused by failure to adjust operations to geological circumstances, and the irregular development of mine workings caused by unexpected geological features, all bear witness to the lack of geological foresight by the industry.Along with the more widespread general use of applied geology, an increasing acceptance has developed during the past ten years of the valuable contribution which can be made by this science to the exploitation of coalfields. In spite of the advances which have been made, there is still a wide scope for further detailed application of geology throughout the coal mining industry in Australia.

Jan 1, 1963

By J L. Mauk

Gladstone Hill, a volcanic-hosted low-sulfidation epithermal prospect in the Coromandel Peninsula, is less than 1 km from the world-class Martha Hill Au-Ag deposit. Gold-silver-bearing quartz veins occur in Late Miocene andesitic volcanic rocks of the Waipupu Formation that are extensively altered. The occurrence, spatial distribution and temporal relationships of hydrothermal minerals have been determined along two cross sections that transect the Amaranth, Gladstone, Cowshed and Moonlight veins. Quartz and pyrite are ubiquitous along these sections. Adularia and chlorite are widespread, but both are scarce in wall rocks adjacent to the Moonlight and Cowshed veins. By contrast, rare hydrothermal albite and epidote are restricted to wall rocks surrounding the Amaranth vein. Illite, which replaces adularia, is widespread and grades laterally eastwards into a zone of interstratified illite-smectite that envelops the Moonlight and Cowshed veins. During late-stage hydrothermal activity, rare calcite formed at depth and uncommon kaolinite and alunite formed at shallow levels. The overall clay mineral zonation with illite grading eastward into interstratified illite-smectite reflects paleothermal gradients of >220¦C to -170¦C towards the margin. The alteration assemblage of quartz, adularia, chlorite, albite, epidote, illite, interstratified illite-smectite and pyrite reflects formation from a near-neutral to weakly alkaline pH chloride water that contained low concentrations of CO2, Late calcite formed from very local descending steam-heated CO2rich water, whereas the rare assemblage of kaolinite and alunite formed from shallow steam-heated acid-sulfate water. Analysis of the available data indicates that the Martha Hill deposit and the Gladstone Hill area formed within a single large geothermal system. We infer that the Martha Hill deposit formed in the main upflow zone, whereas the Gladstone Hill area may have formed adjacent to this upflow zone.

Jan 1, 2001

By Madgwick J. C

The monosaccharides glucose, galactose and arabinose, and the polyols glycerol and mannitol (0.1 Ufo WIV) supported pure and mixed culture heterotrophic bacterial manganese leaching of solid pyrolusite (MnO2, 2% W/V) to yield 14-38 mg/litre manganous ion in 3 days from a simple mineral salts media at 30°C. Supplementation of pure bacterial isolates growing on glucose with soluble intracellular photosynthate from freshwater algae (0.07 g/l carbohydrate) and marine algae (0.11 g/l) led to an improvement in Mn++ yields of 24 and 100 per cent respectively. Extracellular products of the freshwater algae (0.3 g/l carbohydrate) boosted recoveries by 57 per cent.

Jan 1, 1982