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Alternative processes for converting coal to liquid products and their stage of development are outlined. The merits of hydrogenationprocesses in general, and the solvent refined coal process in particular, are stressed. Bench scale experimental hydrogenation procedures used by the Australian Coal Industry Research Laboratories Ltd. (ACIRL) to study the liquefaction of Australian coals and correlations between properties of such coals and their conversion to liquid products are described. Factors involved in assessing investment and operating costs for modern hydrogenation based coal refineries of different capacities are described with reference to a recent study undertaken in N.S.W. The significance of coal properties such as yield and yield structure of total liquid products and how they and other factors can influence the economics of the coal refining operations are discussed.

Jan 1, 1977

By Little T. N

The Western Australian School of Mines is continuing to investigate the blasting techniques and mining strategies that are used for ore/waste separation (or high grade/low grade ore separation) or to prevent ore and waste mixing. The aim of all the mining strategies is to produce an optimum product. The optimum product is one which contains no diluent and undergoes no mixing of the various identified ore and waste blocks and is fully recovered at the minimum overall operating cost. The current study includes the use of computerised Knowledge Based Systems (KBS) technology to assist the user with the blast technique selection and blast design process. These aspects are highly dependent on the geology. (geometry, rock mass properties, grade distribution), explosive performance and the expectations of the mining company in terms of production rates and equipment utilisation. Most of these factors are not well defined and nor are they easy to quantify. However, a large amount of knowledge does exist and is available in the following forms: rules of thumb, empirical formulae, engineering judgement and past experience. KBS techniques are well adapted to handle such"forms of knowledge. The primary objective of this paper is to illustrate an approach for the use of Knowledge Based Systems during the analysis and interpretation stages of the blast design process. In particular, the components and methodology of the developed system are described for selective open pit gold mining. The Knowledge Based System developed was written using the declarative programming language PROLOG.

Jan 1, 1990

By Paine GG

The in-situ retorting of shallow oil shale deposits is an attractive alternative to the material handling problems of conventional open pit mining techniques, which involve removing overburden, fragmenting and transporting the shale to a fixed retort, and finally disposing of the hot spent shale.For in-situ retorting to be successful, the oil shale has to be fractured and the fragmented rock expanded into a void, to allow controlled propagation of a flame front through the in-situ retort. The principles of cratering with explosives have been used to develop a process for the in-situ fracturing of a thin oil shale deposit overlain by a formation of porous rock. The overlying porous rock formation is first compressed by explosive charges to create voids in the porous rock. The oil shale is then fragmented and pushed in to the voids with separate explosive charges. This paper discusses methods of creating voids in porous rocks with minimal surface disturbance, and then methods of obtaining the most uniform fragmentation of the shale. The whole process can be completed, in practice, in one blast. The results of an experimental blast are presented, and possible modifications are then discussed.

Jan 1, 1985

The use of teleoperation in mining is increasing due to requirements to improve safety and reduce the number of people required to work in remote and difficult environments. We recently completed a project to develop a teleoperated control system for a rock breaker at an iron ore mine in the Pilbara region of Western Australia, with the objective of demonstrating the feasibility of remote rock breaking over long distances. This required controlling both the rock breaker and an array of pan-tilt-zoom (PTZ) cameras using joysticks. Controlling the cameras distracted operators from the primary task of controlling the rock breaker to position and fire the hammer. This lengthened task times as both the operator's attention and their hands have to swap between different control interfaces. In this paper, we present a novel design using human eye gaze as an interactive input for the remote camera control. It follows a simple and natural design principle: Whatever you look at the screen, it goes to the centre. A prototype system has been implemented by integrating computer vision based eye tracking technology, with the advantage of being real-time, robust and marker-less. We conducted a user evaluation, where users undertook a control task while obscuring the direct view of the working area and using a remote camera to transfer the live video stream as the visual feedback. Subjects were required to participate in the experiment using eye tracking camera control and traditional joystick control respectively. The statistical analysis of objective measures indicated that our novel eye tracking control significantly outperformed the joystick control. The results of the post-experimental subjective measures also revealed much higher user preference for using eye tracking control, which provides clear evidence that this design is a better interface for remote camera control in mining teleoperation settings.

May 1, 2010

By T Baumgartl, B Richards

Covers on waste rock and tailings remain the primary choice for closure planning where the purpose is to create an environment where water ingress into reactive material can be controlled and/or prevented. In semi-arid and arid environments, dry cover systems are the preferred option with the design intention to absorb rainfall and to prevent deep drainage. Although the average amount of rain typical for semi-arid environments is relatively low and evaporative demand is high, the seasonal and annual distribution may vary greatly. Rocky substrates are often the only choice for the construction of covers due to economic constraints or availability of suitable materials. While the water holding capacity may be suitable for the application of a dry cover design in arid and semi-arid climates, some of these covers bear the risk of preferential water flow when rain events are intensive or occurring at high frequency. The objective of this presentation is to demonstrate the occurrence of preferential flow through rock containing dry cover systems. A regional classification for the applicability of dry covers is attempted to delineate those regions of Australia where the characteristic of the rainfall pattern increases the risk of failure for dry cover designs. CITATION:Baumgartl, T and Richards, B, 2016. Rainfall patterns rather than climate classification control cover design for closure, in Proceedings Life-of-Mine 2016 Conference, pp 89–92 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Slater R

The initial planning and detail design phase leading to the development of a 7.5 m internal shaft to service the deep 3000 and 3500 copper orebodies at Mount Isa, Queensland is well advanced. The choice of internal shaft access was made over alternative methods such as a decline from existing levels and borehole hoisting. The resulting access development requirements and shaft configuration for production have been determined. Several techniques are being studied for shaft development. These include the application of blind shaft drilling and large hole reaming methods as well as conventional sinking techniques. As the 3000/3500 Orebodies extend from 1000 metres to more than 1800 metres below the surface, high stress conditions and ground temperatures ranging from 45CC to 62CC are anticipated. The effect of these on the methods being investigated to create a favourable working environment will influence the final choice. Exploration diamond drilling is in progress to confirm the geology of the orebodies so that planning for their extraction including refrigerated ventilation concepts can proceed.

Jan 1, 1982

By T Laurencont, C Unger

The Mount Morgan minesite, located approximately 40 km SW of Rockhampton in Central Queensland, comprises 270 ha of unrehabilitated land which is the currently the major source of acid mine drainage run-off and seepage to the adjacent Dee River. Additionally, the minesite hosts an Open Cut Pit which contains 9000 ML of acidic and metal-rich water. In the absence of active management of water in the pit, there is a 50 per cent probability of an uncontrolled spill occurring in future years. The development of a contingency plan for management of overflow from the pit in the short term, has incorporated findings from numerous studies relevant to the Open Cut Pit including, but not limited to, water balance, contaminant source identification, toxicity testing, water quality profiling and limnological modelling, and estimates of probability of overflow. Extensive stakeholder consultation and peer review were also undertaken during the formulation of the contingency plan. The medium-term goal of lowering the water level in the pit to reduce the current high probability (50 per cent) of uncontrolled overflow to acceptable levels of risk is proposed to be achieved by a campaign of chemical water treatment. The treated water will be discharged to the Dee River, and sludge returned to the pit. The methodologies used for the selection and development of the water treatment process, that is proposed to involve treatment with lime, are described. Water treatment is the short- to medium-term component of a long range rehabilitation plan for achieving a negative pit water balance, and sustainable management of acidic water across the whole site. Achieving this ultimate goal will involve: reducing the inputs of water to the Open Cut Pit such that the annual water balance is zero or net negative, thus removing the need for water treatment in perpetuity; maximising, by surface rehabilitation works, the quality of run-off reporting to the Dee River; and minimising the volume of acidic seepage reporting to the seepage interception system. Possible strategies for achieving this long range goal consistent with overall site rehabilitation objectives are currently being developed and costed.

Jan 1, 2003

Silica and limestone fluxing levels in copper smelting slags were studied. Copper concentrates with flux additions were smelted to matte (55.5 per cent Cu) and slag in a pilot scale submerged combustion furnace.Results indicated that oxidic and sulphidic copper levels in slags were minimised with a slag Si02 level of 36 per cent and a SiO2/CaO ratio of 5.5. Total copper losses in slags were 0.6 per cent under these conditions.To produce the desired slag chemistry, additions of bulk silica and limestone to copper concentrates of fluctuating grades were predicted numerically. The method employed the solution of two simultaneous equations, each respectively for silica and limestone calculations.The predicted flux additions were applied in a further series of tests and the resultant stages were found to be satisfactory. The method is applicable to smelting 'operations which employ two flux bins, with weigh feeders, so that slag chemistry may be controlled with the flux/concentrate feed mix.

Jan 1, 1985

The results of about 30 years of exploration and mining activities and research studies in the Kambalda mining district, Western Australia, have led to general agreement that the komatiite-associated Ni sulphide ores formed as a result of igneous processes (Ross, 1974; Ross and Hopkins, 1975; Gresham and Loftus-Hills, 1981; Cowden, 1988; Lesher, 1989 and many others). Despite this agreement, the controls on sulphide supersaturation and concentration of the resulting sulphide in a limited zone, remain uncertain and controversial. A major uncertainty is the source of sulphur in the ore deposits. Two principal sulphur sources have been proposed: 1. komatiite lava/magma (Hudson, 1972; Naldrett, 1973; Lesher et al, 1981; Cowden, 1988; Foster et at, 1995), and 2. sedimentary material (Groves, Barrett and McQueen, 1979; Lesher, Arndt and Groves, 1984; Lesher, 1989; Lesher and Campbell, 1993). Resolution of the uncertainty regarding the sulphur source is required for a complete understanding of the controls on ore formation, which in turn would significantly impact exploration strategies in the Kambalda mining district and elsewhere. This paper reviews the constraints on sulphur sources for the komatiite-associated Ni sulphide ores in the Kambalda mining district. The focus is on the general characteristics of the ores and surrounding rocks: individual ore deposits are not described, though specific examples are noted where appropriate. The stratigraphic and volcanic settings and geochemical (major and trace element and isotopic compositions) characteristics of the ore deposits and surrounding rocks are considered within the context of the competing sulphur source models, and future directions of research in the district are noted.

Jan 1, 1996

By Van Heuzen JA

The extensive deposits of brown coal in the Latrobe Valley form the major solid fuel resource in Victoria and are the energy source for most of the State's power generation. This paper describes the coalfield resources allocated for electricity generation and a potential sequential develop- ment of these areas in future years to supply future power stations.

Jan 1, 1982

By Ho E

Analyses of several nickel mattes from around the world show a significant variation in their copper content. Typically, matte contains an alloy, heazlewoodite and a copper sulphide phase. The various commercial methods of processing these mattes are reviewed and some of the fundamental factors which determine the choice of leaching system are discussed. Electrochemical studies on pure heazlewoodite and millerite in sulphate and chloride media are compared which show that nickel sulphides react via a series of nickel deficient sulphides and exhibit passivation as nickel is removed. Differences in the electrochemical behaviour of nickel sulphides in chloride media are attributed to greater crystallinity of sulphur and less formation of'NiS2. The electrochemistry of mattes differs because of the presence of alloy and copper. Copper in the matte modifies the potential for alloy dissolution and the rate of anodic dissolution of nickel. At elevated temperatures, Cu(II) in solution exchanges with NiS and completes the leaching of nickel at relatively low potentials without significant oxidation of sulphur to sulphate. It is concluded that there are fundamental advantages to leaching nickel matte in chloride media using Cu(II)/Clz as the oxidant.

Jan 1, 1996

During the last 12 years the dominant theme at Mount Isa has been production expansion. Production rate of 3,200 tons per mine day in 1953 increased to 11,000 tons per mine day in 1960, completing the first stage of the programme. The second stage is still in progress. It is planned to increase production of lead and copper ores to 19,500 tons per mine day in 1968.Current mine workings comprise an area 2 miles long and 1/2 mile wide, the deepest production level being 2,000 ft below surface. During the next 10 years it is anticipated that mining will be carried out to a depthof 3,200 ft below the surface. The rapid extension of the mine has necessitated frequent re-appraisals and modifications to the primary ventilation system, and a system with considerable in-built flexibility has gradually evolved. Since 1953, volume circulation has increased eight-fold to approximately 2,400,000 c.f.m.To suit various mine operating requirements, a combined pressure-exhaust system of ventilation was adopted.The usefulness of this system is at a maximum when the fans installed permit ready changes in the location of the boundary between adjacent spheres of fan influence.Air flow through openings to the surface can be controlled or used as required. This feature is considered necessary for a mine where underground workings are comparatively shallow and caving to the surface willoccur.A major heat problem exists due to climate conditions, high geothermic gradient (one degree Fahrenheit in 95 ft), and oxidation in leached and brecciated areas.Because of this, quantities of air far in excess of the minimum requirements for dust removal are required to ensure satisfactory environmental conditions. In assessing fan pressure, consideration was given to 1. the mine resistance, and the requirement for pressure differential capability,2. the pressure requirement for deeper mining, with due allowance for booster fan use where appropriate,and3. the desire to avoid fan operation at pressure duties above the region of peak fan efficiency.The latter feature provides a safety margin between maximum operating pressure and the stall point of the fan.

Jan 1, 1967

By Ellery B. I

Field investigations recently undertaken by Utah Development Company (U.D.C.) have been developed to allow the assessment of ground conditions relevant to the use of large bucket wheel excavators for pre-stripping overburden. "Bucketwheel diggability" predictions were made on the basis of a wedge test which was perform- -ed in the field on nominal 150 mm diameter drill core samples. Specific separation force (calculated from the wedge test results) for different rock horizons were theoretically related to the excavation rates of various sized bucketwheels, i.e., "bucketwheel diggability". The specific separation force was shown to vary with lithology, structure, weathering and moisture changes. By correlating these features between boreholes, an overall assessment of bucketwheel diggability was then made. The approach adopted to assess bucket- wheel diggability incorporated various levels of investigation. Initially, a reconnaissance stage provided information from widely spaced 150 mm cored holes to compare and contrast areas with differing bucketwheel digging char- -acteristics. The following stages progressive -ly added to this information, until finally, between hole correlations, allowed calculations to be made of volumes of materials of similar

Jan 1, 1981

The design of a sand pump is similar in principle to that of a water pump but differs in several areas. Results of experiments on sand pump performance have been summarized and values of design parameters quoted for optimum results. Typical performance data are also Included.

Jan 1, 1973

By K Sanematsu

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore deposits of rare earth elements (REE) in South-East Asia are classified into four types: carbonatite, allanite, ion-adsorption and placer. Occurrences of the carbonatite deposits are confined almost exclusively to the Red River Fault Zone of northern Vietnam. Since the carbonatites contain dominantly REE fluorocarbonates (eg bastnasite) and lesser amounts of monazite, they are rich in light REE but poor in heavy REE. The ion-adsorption type deposits and prospects were found in Myanmar, Vietnam and Thailand. The ion-adsorption ores generally show lower REE grades than those of the carbonatite type and placer deposits; however, they could be enriched in HREE, which are more precious and scarce commodities than LREE. The ores consist of weathered granites with a significant amount of ion-exchangeable REE, which are extracted by using a dilute electrolyte solution. The ion-exchangeable REE are likely to be sourced from REE fluorocarbonates, allanite and titanite because these minerals are relatively susceptible to weathering and release REE3+ ions into soil water. In contrast, monazite and xenotime are resistant to chemical weathering and could form placer ores. Placer monazite and xenotime have been processed as by-products of placer Sn, Zr or Ti in Malaysia, Thailand and Indonesia, although the current production is small.CITATION:Sanematsu, K, 2015. Rare earth element deposits and prospective areas in South-East Asia, in Proceedings PACRIM 2015 Congress, pp 671–678 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Armstrong M, Kleingeld W. J

Current low prices for many metals mean that deposits have to be mined at high cut-offs (relative to their mean grade), which means that only a small percentage of mining blocks are above cut-off. Worse, at such high cut-offs, the blocks above cut-off are usually not grouped into convenient clumps for mining; they tend to be split into small isolated patches that are difficult to reach and hence expensive to extract. Companies wishing to acquire mineral properties have to be able to work out quickly what percentage of blocks are above cut-off and what can effectively be mined given the mining method envisaged. Moreover they need this information within a relatively short-time. The work presented here relates to typical South African gold mines (ie tabular orebodies) but the long-term objective is to develop tools for quantifying the impact of reserve breakup at high cut-offs for a wide range of underground mines including those that are not tabular. The mining method and the sampling procedure determine whether ore blocks can effectively be located and extracted economically. This project studied the impact of these two factors on the recoverable reserves for Witwatersrand gold mines. In order to be repeatable, the tests were done on numerical models of the deposit obtained by geostatistical simulations. To ensure realism, the orebody model and the mining scenarios were based on a specific mine. The recoverable reserves (ore tonnage above cut-off, the corresponding metal quantity and the average grade) were calculated for a wide range of cut-offs for four mining scenarios, as well as for the base case of free selection: ò Scenario 1: Blocks are taken if their true grade is above cut-off and if they are accessible from a raiseline (no information effect, no marginal blocks). ò Scenario 2: In addition to the accessible pay blocks, adjoining marginal blocks are taken (no information effect, + marginal blocks). ò Scenario 3: Blocks are taken if their estimated grade is above cut-off and if they are accessible from a raiseline. Here the estimator is the average of the face samples (information effect, no marginal blocks): ò Scenario 4: Accessible pay blocks are taken if their estimated grade is above cut-off. Adjoining marginal blocksare also taken (information effect, + marginal blocks). ò Free selection: All blocks whose true grade is above cut-off are taken irrespective of their accessibility. The results can be presented in different ways, for example by plotting ore tonnage above cut-off versus cut-off grade, or metal tonnage above cut-off versus cut-off grade etc. As expected, this shows the hierarchy between the five scenarios from the free selection base case to scenario No 2 (true accumulations, pay +

Jan 1, 1995

By N Nosaka

Sinter plants currently have to use many types of ores with different properties due to the great demand for iron ores, which was driven by the massive growth in Chinese iron and steel industry. On the other hand, the development of iron ore mines is limited and the quality of iron ores is in a tendency of deterioration. Therefore, the quick evaluation of iron ores has become more important for a stable sintering operation. In addition to such a background, the CO2 gas emission should be decreased from sinter plants according to the Kyoto Protocol on reduction in greenhouse gases. The present paper first describes the methods for testing the metallurgical properties of iron ores, which use a small volume of sample mainly focusing on magnetite ore that is effective for reducing CO2 and NOx emissions from sinter plants. The sintering properties of ores are evaluated separately according to each stage in sintering process, that is: heating stage before melt formation, primary melt formation in adhering fines layer of pseudo-particles, and assimilation of nucleus ore particle with calcium-ferrite system melts.Next, the application of the tests to the blending ores is introduced showing examples of the studies on the effective usage of the magnetite ores with Marra Mamba type ores.

Jan 1, 2005

By Mckenzie CK, Leach KR, Bateman KW

Modelling of industrial coal flotation based on data collected in several Central Queensland flotation plants and supplemented by laboratory data is discussed. The model is kinetic in form and provides the basis of an automatic control system. The important features of the model are, 1. a distribution of flotation rates for each species of particles corresponding to the range of particle sizes, 2. a physical restriction on the removal rate of solids in cells where froth 'overloading' occurs. In this condition the removal rate of solids is proportional to the removal rate of water, 3. enhanced particle floatability due to increasing collector addition where froth overloading does not occur, 4. a second mechanism of recovery of all particles by mechanical associ- ation with water. This mechanism is particularly important in the recovery of fine high-ash species.

Jan 1, 1978

Base metal skarns have provided most of South KoreaÆs Pb-Zn production since the end of the Korean War, with the bulk of production coming from the Yeonwha group of mines. Currently only the Kumho Zn-Pb mine remains in production, while magnetite skarns are mined as iron ore at the old Yomisan and Ulsan base metal deposits. Base metal skarns within Korea fall into two groups; those hosted in Cambro-Ordovician limestone sequences, situated mainly in sub-basins in the northeast of the peninsula and those hosted within carbonate volcaniclastics of the Cretaceous Gyeongsang Basin, in the southeast. Sulphide mineralisation is dominated by sphalerite, lesser galena, arsenopyrite and pyrrhotite, with subordinate chalcopyrite and molybdenite with Ag-Co credits. Skarns are composed of pyroxene-clinopyroxene-garnet-carbonate-quartz and magnetite, grading into silica-chlorite hornfels. Most of the significant deposits display both pipe-like and stratabound morphology. In the Hwanggang district, a zoned distribution of Ordovician carbonate hosted, polymetallic Mo-W and Zn-Pb-Cu-Ag base metal deposits is observed around the margin of a Cretaceous granite intrusion. Similar polymetallic zoning is recognised in the Sangdong district, where deposits include Sangdong (W), Abisan (Au-As) and Yomisan Northwest (Zn-Mo) and Yomisan Southeast (Zn-Cu-Co), hosted in Ordovician carbonates in proximity to Cretaceous quartz porphyry intrusives. The Taebaeksan district hosts the largest deposits at the Yeonwha group of mines. Although production ceased in 1993, significant resources remain, hosted in Ordovician limestone and dolomite that have been intruded by Cretaceous quartz porphyry dykes. Deposits in the Cretaceous Gyeongsang Basin consist of bedding concordant, vertically stacked base metal skarn mineralisation at several stratigraphic horizons, connected by carbonate-base metal veins with a pipe-like geometry. Evidence such as massive sulphide layers and restricted proximal carbonates suggest mineralisation was initially partly syn-depositional, with both base metals and carbonate venting onto a lake floor, being reconstituted to skarns by later magmatic activity. Skarn mineralisation is universally closely associated with the Cretaceous Bulgugsa Series acid intrusive activity. A common intrusive-structural relationship is recognised at some deposits, with bedding plane and imbricate thrust faulting, introducing felsic intrusives as sills. These intrusions probably introduced the base metals, carbonate, boron, heat and silica, which metasomatically reconstituted the carbonate lithologies to form skarn assemblages. The Korean base metal skarn deposits are regarded as Zn-Pb chimney-manto skarns and display similarities to the Mexican manto type deposits.

Jan 1, 1999

Since the announcement of early experimental work on rotating magnetic field (RMF) separation at the Sixth Mill OperatorsÆ Conference in 1997, the concept of RMF separation has been developed and tested further, and a range of separator designs is now being developed for the mineral processing industry. Shortened, but full diameter, prototypes of these designs are now available for test separations. The main advantage of RMF low and medium intensity attraction separation is the significant reduction in particle entrapment. This reduction is so significant that RMF separators are capable of operating very close to their theoretical limit for separator precision. This makes small laboratory RMF attraction separators ideal for low to medium intensity magnetic sample analysis, and larger separators ideal for applications requiring sharp magnetic susceptibility splits. Feedrates and separation rates are comparable to those of conventional attraction separators. Although RMF attraction separators are now well advanced in development, RMF rotation separation is still in the early experimental stage. The exception to this is the dry particle rotation eddy current separator that offers eddy current separation of small non-ferrous metallic particles from about 2 mm down to about 100 microns. Wet small particle eddy current separation is also possible, but has not yet been developed to a practical stage.

Jan 1, 2000