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The evolution of mineral sand mine rehab ilitation techniques have been techniqually based. Research and investigations have been carried out by government authorities, mining companies and academic institutions. Protection of the physical and biological environments is a vital part of any mine oper- ation. The Mineral Sands Mining Industry in New South Wales is successfully working within the State's environmental framework and is meeting; community requirements and expectations concerned with the environment and mine rehab- ilitation. Keywords: Environment, mineral sands mining, mine rehabilitation, revegetation.

Jan 1, 1986

By Meakins R. L, Talaska A, Kenny D, Haycraft J. A, Dickson B. L

A vehicle-mounted radiation detector interfaced to a microprocessor called PRAM (programmable radioactive analyser mobile) has been developed to provide grade control for selective mining of a soft rock uranium ore. The grade of ore over which the vehicle passes is determined and indicated by several coloured lights to a pegman who walks behind the vehicle. Coloured pegs are then laid out to mark the uranium grade ranges on the floor of the mine pit. Comparison between grade ranges determined by the PRAM and by prior drilling and downhole logging at the Yeelirrie deposit, Western Australia indicate good agreement. Use of the PRAM decreases the cost, manpower and time required to grade extensive areas of a mine pit floor.

Jan 1, 1982

No paper was submitted for the proceedings, verbal presentation only (no material available).

Jan 1, 1998

A tectonic interpretation of the Coromandel Peninsula which suggests that the basement underwent tensional collapse at its northern and southern ends would permit more ready penetration of late stage magmatic fluids. This hypothesis is consistent with regional trends of the chloride content of low grade geothermal waters and of the yield of gold and silver per unit weight of quartz worked. The consequences of such a model are that mercury should not only be a good pathfinder for Coromandel gold, but that it should be correlative with ratios of base metals high in the zoning or paragenetic sequences to those lower in the sequences. This is demonstrated successfully in an area of mineralisation in the southern Coromandel.

Jan 1, 1987

This paper examines the reform of mining legislation over recent years, the establishment of new Crown land management agencies, and the role of the Crown and environmental groups in nature conservation inNew Zealand. It describes the relationship of the minerals industry to the Department of Conservation and environmental groups over recent years, and the prospects for mineral development on the Conservation Estate in future.

Jan 1, 1995

By Bratt G. C

When zinc is electrowon from concentrates or residues of high manganese content, the zinc sulphate electrolyte may contain high levels of manganese. The manganese level is usually controlled by removal of manganese at the anode as the dioxide during the zinc electrodeposition stage.By increasing the temperature of an electrolyte containing 8 gll manganese from 35°C to 90°C, decreasing the acidity from 100 gll to 30 gll, reducing the current density from 432.A.m-2 t6 286 A.m-2 and using new lead anodes containing over 0·75 per cent silver, the current efficiency for manganese dioxide removal was .increased from less than 1 per cent to over 20 per cent.At the same time the current efficiency for zinc deposition was maintained above 90 per cent by additions of high molecular weight cationic polyacrylamides to the cell. By utilization of these conditions in a small number of cells, the manganese level in the circuit could be economically concrolled to any desired level.With these conditions the formation of the dioxide changes from an indirect route, via Mn04-, to a direct oxidation of Mn2+ to Mn02.The incorporation of impurities such as Pb, K, NH4, Cu, Ni, or Fe makes the deposit unsatisfactory for direct use in Zn - Mn02 dry cells. The deposit structure changes from cryptomelane at low temperature to y3-Mn02 at high temperature.

Jan 1, 1975

The Wongawilli system of mining has been in use for over 30 years and has enabled high production rates and acceptable extraction ratios to be achieved in seams less than 4 m in thickness. A modification of the Wongawilli system has been developed to permit the use of a continuous miner and mobile equipment to extract a coal seam 6 m thick. Following physical and mathematical model studies the new mining method is now undergoing field trials at Collinsville, Queensland. Progress of the field trials to date has achieved 99 per cent extraction of the upper slice by remote control operation of the continuous miner and established the feasibility of installing resin grouted wooden dowels in the coal floor to reinforce the coal septum. The method is explained in the text. Monitoring of the goaf gases as an early indication of spontaneous combustion has been incorporated in the mining cycle by placement of tubes in the goaf as the face retreats and continuous analysis of the goaf gases made at the surface by the National Coal Board tube bundle monitoring system.

Jan 1, 1980

Gold mineralisation at the Macraes Gold Project is hosted in the Hyde-Macraes shear zone and can be traced for ~30 km along strike, although economic resources are confined to a seven kilometre section in the vicinity of the Macraes  township. The shear zone, which typically dips at a low angle (~20¦) 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, 'lode schists' and quartz-vein stockworks. Mine geology and grade control activities are designed to ensure accurate definition of ore and waste as well as the accurate prediction of ore grade. Grade control involves an integrated process of blast hole sampling, geological mapping and geostatistical modelling. Geological mapping is carried out post blasting by means of excavating trenches across are zones defined by assay data. Conditional Simulation is used to model raw assay data to define ore-waste contacts and estimate ore block grade, although, geologically defined contacts have precedence. Low angle ore zones impart a wedge shaped geometry to many ore blocks. These ore blocks are bounded by contacts that can be selectively mined to, thereby reducing misallocation of ore and minimising grade dilution.

Jan 1, 2001

Two Variable Real-Time Algorithm for Cone Crusher Control

Sep 13, 2010

By Hudson S. B

With a particular electrode configuration, and a particular combination of electrode voltage and roll speed, a relatively small increase in electrode voltage, or a relatively small decrease in roll speed, resultsin a marked improvement in the separation of zircon from ilmenite. In general, fine minerals can be separated using a higher roll speed, or a lower electrode voltage, than is required to separate coarse minerals. The ionizing electrode should be reasonably close to the point at which mineral is fed on to the roll, and nearer to the roll than the non-ionizing electrode. The optimum conditions for the separation of zircon from ilmenite may not apply for the separation of other non-conductors from other conductors.INTRODUCTIONAlthough the high tension separators used in the Australian beach sand industry are efficient, this efficiency has been gained very largely by a process of trial and error, and not by a systematic study of the effects of changes in the operating variables. The optimum roll speed for a particular electrode position and electrode voltage, and the optimum electrode voltage for a particular roll speed and electrode position, can both be determined quite readily. It is not so simple to determine the optimum electrode position for a particular electrode voltage and roll speed. The reason for this is that the electrode used in high tension separators consists of two parts-an ionizing and a non-ionizing electrode respectively. The angular and radial positions of these electrodes, relative to the feed roll and to each other, affect the behaviour of conductors and non-conductors to varying degrees.

Jan 1, 1962

The theme of this conference is æRediscover OtagoÆ and the conference occurs during a resurgence of economic activity in New Zealand, and in particular at a time when the Macraes Gold Project has had a significant effect on mining and business activity in Otago. The Macraes Gold Mine has implemented a Zero Accident Programme and this paper reviews some of the factors responsible for the implementation.

Jan 1, 1992

By Coin CDA

From a study of coke samples obtained from the tuyere level of four Australian Blast Furnaces, the nature of in-furnace coke degradation has been investigated. At the periphery of the raceway is a concentration of fines and the lump coke appears dull and rounded. However coke from the deadman is angular and relatively undegraded. Cokes made from higher rank coal appear to suffer preferential attack of the reactive maceral derived component (binder). The coke from lower rank coal appears to be attacked non-preferentially by the solution-loss reaction. Initial attempts to simulate these phenomena have given results consistent with these findings. From chemical analysis of the tuyere probe samples there appears to be a relative increase in carbon and decrease in-.sulphur and phosphorous between stockline and tuyere level. An overall decrease in coke mineral matter derived material was noted and associated with this was a significant gasification of silicon. Consequent formation of silicon carbide was noted.

Jan 1, 1981

By K L. Brown

Sampling and analyses of deep waters from Wairakei and Rotokawa geothermal systems indicate a wide range of precious metal concentrations (<0.1 to 23 ppb Au; 6 to 2400 ppb Ag), suggesting that eastern ôandesiticö TVZ geothermal systems (eg Rotokawa) have higher aqueous gold and silver than western ôbasalticö geothermal systems (eg Wairakei); this interpretation is consistent with known occurrences of high grade precipitates in wells from eastern systems. The fact that the deep waters are undersaturated in gold further suggests that the aqueous gold concentrations of deep waters are limited by metal availability. The flux of gold for the two systems ranges from ~1 to 50 kg Au/yr, and the flux of silver ranges from 65 to 6900 kg Ag/yr. At Rotokawa, it only takes ~600 years to flux one million oz of Au and >100 million oz of Ag. The supply of hydrothermal gold and silver is obviously important during genesis of an epithermal deposit, but ore formation also depends on the existence of a suitable ôtrapö that efficiently extracts metal from solution in a small volume of rock. Such traps seem to have been poorly developed until geothermal drilling in the TVZ.

Jan 1, 2006

By Ennis P. C

The Mt Keith ultramafic intrusive extends for about 200 kilometres from Agnew in the south to Wiluna in the north. It forms the host for a number of nickel sulphide orebodies including Mt Keith and Honeymoon Well. Long fibre minerals are associated with the orebodies. The presence of these minerals impacts on the issue of tailings disposal from several standpoints, particularly the slurry beaching properties and dust generation from dry beaches. Central thickened discharge (CTD) is an innovative method of tailings disposal that involves stacking tailings in a low conical hill instead of storing them in cells. In appropriate circumstances this leads to savings in capital costs and operating expenditure. The method was introduced to Australia in 1981, and is currently employed at four operating mines, Elura and Peak Gold, both at Cobar in NSW, McArthur River in the Northern Territory, and Union Reefs near Pine Creek, also in the Northern Territory. It is the proposed method for Century Zinc and Ernest Henry, both in Queensland. The paper describes laboratory test work and design parameters for the application of the method to tailings disposal at Honeymoon Well and compares them with comparable data for other CTD systems. Of particular relevance for design purposes are beach slope, density, and water recovery. Wind tunnel tests were conducted on the Honeymoon Well tailings samples to investigate dust generation from the dry beach surface and it was concluded that dust generation from an undisturbed beach would not occur because of crusting.

Jan 1, 1996

From August 1962 to June 1976 Peko Mines Ltd. produced Gold Bullion at the Peko Control Mill using 18x24 Denver Mineral Jigs and strake tables. Gold ores treated during this period were obtained from Orlando, Juno and Ivanhoe Mines and from the Warrego Mine after 1974, all in the Tennant Creek Area of the Northern Territory. With the downturn in copper prices Warrego Copper ore mining ceased and the copper Smelter closed down in February 1974, Warrego gold ore continued to be treated in the Peko Concentrator.

Jan 1, 1978

By H R. Watling, W van Bronswijk

Of the various copper sulfides in the EarthÆs crust, chalcopyrite is by far the most common. This mineral is also the most difficult to leach, with hydrometallurgical extraction processes characterised by prohibitively slow kinetics. While a number of processes, including leaching at atmospheric pressure and temperature, pressure leaching at higher temperature, and bioleaching of concentrates in stirred tanks and whole ores in heaps have been demonstrated to some extent, there is currently no full-scale unit process for the hydrometallurgical extraction of copper from chalcopyrite ores. Titan Resources NL operated a test bacterial heap leach at Radio Hill, Western Australia in 2001, to extract nickel and copper from a mixed sulfide ore that contained significant amounts of chalcopyrite, pentlandite and pyrrhotite. A proprietary mixed bacterial culture was used to inoculate the heap, and the nickel and copper were precipitated from the resultant solution as mixed hydroxides. Although 65 per cent of the copper from the Radio Hill heap was eventually recovered, the rate of extraction followed an unexpected trend, as the initial rates of copper recovery were much slower than column tests had suggested. It was postulated that this was due to dissolved copper precipitating as covellite or chalcocite in the most poorly aerated zones within the heap, ie furthest from the aeration pipes at the base. It was further hypothesised that the lack of oxidants (oxygen, ferric iron) and the likely inactivity of bacteria in these areas limited the re-dissolution of such secondary copper precipitates. In this study the above hypothesis was tested in column experiments using the same mixed sulfide ore and a synthetic leach solution. One set of columns was aerated and another set was operated without aeration. Results showed that precipitation of copper occurred regardless of whether the column was aerated or not. The results suggested that pH of the leach solution played a significant part in the precipitation of the copper. Further column tests revealed this to be the case. These results are described here in detail.

Jan 1, 2004

Study on Mineral Processing of Refractory Copper-Nickel Ore

Sep 13, 2010

By Nguyen V. V

The development of structural defects in the overburden material immediately behind a production blast was studied using surface and subsurface techniques. A significant increase in vertical and horizontal fracture intensity was recorded. The extent of fracturing into the highwall appeared to be dependent on the structural and petrologic characteristics of the various lithological units and the relative position of the explosive charges. A shallow zone of disruption to a depth of 10 m and extending to around 30 m from the newly formed highwall crest was recorded. Horizontal fractures in lower units of the overburden sequence were recorded at distances up to 50 m from the new highwall Face.

Jan 1, 1981

By Kavetsky A

In surface mining operations, the ease with which a muckpile may be dug is a dominant factor in mining efficiency. Within broad limits, this is largely dependent on muckpile shape and looseness within a muckpile. Moreover, prediction of grade boundary movement and subsequent dilu- tion is of interest to most open cut mines. Such a predictive tool would enable blast design changes to be made to reduce mixing of certain grade regions. At the very least, a good knowledge of post-blast region bound- aries can reduce layout of the grade boundaries and decrease grade dis- crepancies between pit and plant. The model presented in this paper is able to consider various options for a production blast and predict consequent muckpile shapes and grade boundary movements in a three dimensional manner. The overburden geometry, hole patterns, hole inclination and charge distribution are all explicit model inputs. The model divides the rock mass into blocks and calculates a velocity for each block. Three controlling parameters are used in the model, which are related to the explosive energy per unit length of blast hole, energy attenuation of the rock mass and inter-row delay, respectively. The output of the model is a 3 dimensional muckpile shape (contour or any cross section) and a contour map of grade distribution within the muckpile. The model parameters are site specific, since their values depend on the rock condition and explosive-rock interaction which varies from site to site. In order to "tune" the model to a particular site, parameter values must be found which reproduce an observed muckpile profile shape from a given blast design. This calibration of the model requires at least one surveyed muckpile profile shape from a production blast. The model parameters which best reproduce that shape are found by a pattern search technique, and may then be used to predict the effect of changes in blast design on muckpile profile shape and grade boundary movement.

Jan 1, 1989

The non-metallic minerals, excluding the construc- tions and fuel materials have for long been the "poor relations" of the Mining Industry of New South Wales. The State is self-sufficient in only a few of the industrial minerals and is almost completely lacking in any of the essential fertilizers. The deficiencies must be met by imports from overseas and interstate and in fact New South Wales imports some quantity of every one of the non-metallics. For the year 1967 the value of non-metallic mineral production amounted to only $9,390,000 or less than 3.5% of the States total of $275,900,000 for all classes of mining and quarrying. In roughly the same period, the 1967-68 financial year, New South Wales imported non- metallic materials, valued at well in excess of $22,000,000 from overseas and over $2,000,000 from interstate sources.

Jan 1, 1969