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The overall systems approach to blast furnace aerodynamics is explored including the time and spatial inter-relationships that exist between the furnace lines, tuyeres, burden characteristics, distributor capabilities and furnace operating practice. Attention is called to the time dependent, three dimensional aspects of blast furnace aerodynamics and to the existence of several zones within a furnace where the flow characteristics are different. Changes in furnace operating practice to take further advantage of fully beneficiated burdens including formed coke are discussed from a practical viewpoint. Lessons learned in a variety of shaft furnaces used for other purposes are discussed insofar as they have a bearing on aerodynamics in an iron blast furnace. Questions are raised about the penetration of hot blast in large furnaces. Operating practices and.proposed solutions are evaluated where tuyeres over iron and slag notches are restricted or plugged. Opportunities are presented for using on-line hierarchical computer systems with adaptive tuning algorithms to provide non-linear control of changing process conditions in real time. This will make it possible for the blast furnace operator to optimise a variety of interrelated paramaters, each with different response times. Potential increases in productivity, fuel savings and improved quality control are believed to be within reach.

Jan 1, 1975

Over the last 20 years the mining industry has played a key role in the further development of many Central Queensland and New South Wales communities. The number of people who are employed by the coal mining industry, the number of transient residents, shift work and the town facilities have all contributed to how the community views the coal mining industry. As the coal mining boom continues and the mining communities continue to grow more emphasis is needed to address the community concerns, specifically the socio-economic and environmental impacts that the coal mining companies may have on these communities. Central Queensland coal mining operations are situated in the Bowen Basin. Many of the towns in the region have been developed specifically for the coal mining industry with 13 - 50 per cent (Australian Bureau of Statistics, 2006) of people living in the communities being directly employed by the mines. The introduction of shift work, differing rosters and the mining boom have resulted in considerable changes to these communities with more transient contractors and permanent employees taking up residence outside of these communities. This change, however, has not been as noticeable in the Hunter Valley region. The Hunter Valley, situated in the Sydney Basin has two main mining towns, Singleton and Muswellbrook. Of the 37 173 (Australian Bureau of Statistics, 2006) people that reside in the communities 13.8 to 16.5 per cent (Australian Bureau of Statistics, 2006) are employed directly by the mines. The Hunter Valley is a large tourist destination due to its many vineyards; this results in a diverse community where mining is not the sole means of employment. Similar to Central Queensland the mining boom has brought more people to the Hunter Valley region, although greater percentages have taken up residence in the communities. The views vary between the two regions on the coal mining industry, specifically on the socio-economic and environmental impacts that the industry may have on the surrounding communities.

Jan 1, 2008

Blast furnace slags which fall into the quaternary system SiO2 - A1203 - MgO - CaO have latent hydraulic properties which depend on the degree of vitrification. When the oxides com- bine to form Calcium Silicate Hydrates and other products of hydration the bonds between elements are at a lower energy level than those which exist in the glassy state. Transition from the glassy state to the crystalline state is thermo- dynamically favoured and, in the context of this paper, such slags possess internal energy. Manufacture of Portland cement is respon- sible for about 3.6 per cent of total industrial energy consumption in Canada. Pyroprocessing accounts for about 83 per cent of this figure or 3 per cent of the total. The processing of blast furnace slag to a condition in which it can be used as a partial substitute for Portland cement requires no pyroprocessing and, on average, only about 11 per cent of the energy needed for Portland cement. In North America the benefits of slag as a cementitious materials have been obscured by other considerations, the most important being commercial strategy. This situation has under- gone radical change as a result of the rising cost of energy, and government pressures to conserve energy.

Jan 1, 1979

By Hamilton LH, Campbell PB

Since fundamental research in applied coal petrography is carried out mostly on polished surfaces, backscattered electron microscopy is most applicable for studying coal in the SEM. By employing this technique coal macerals can be easily identified , and information on the relations between maceral groups, mineral matter and trace elements are highlighted by grey level contrasts. This type of information is valuable in coal technology and cannot by normally revealed by the light microscopy (e.g. the distribution of inherent mineral matter).

Jan 1, 1989

The paper discusses the use of animated dynamic numerical simulations to support design and operational decisions in the mining industry. The basis of the simulations discussed is a queuing theory engine with added features that enable continuous processes to be included in simulations. This approach is well suited to the needs of the mining industry which has a mixture of discrete events interfaced to a variety of continuous processes via various forms of surge capacity. Examples are given of the benefits of animation in communicating concepts to those with limited domain knowledge and simulation as a tool that facilitates the sharing of understanding between the stake holders of a system. The analytical content of the paper addresses conflict for resources within systems, the constraints imposed by human and other types of resources, and the impact of external events. Examples are presented showing the use loop diagrams and Gantt charts in the recognition conflict, and its causes. and the use of utilisation logs to identify opportunities for cost reduction.

Jan 1, 2009

By Hoffmann CF, White NC, Tedder IJ, Wood DG

Since the discovery of Pajingo in 1984, the northern Drummond Basin has emerged as a significant new gold province, and has become the focus of intense exploration for epithermal gold mineralisation. Prospects in the Conway area are hosted by felsic to intermediate lavas and volcaniclastic rocks near the base of the Drummond Basin sequence. These Drummond Basin rocks appear to represent favourable hosts to mineralisation because they are cut by structures which could have focussed and channelled fluids on a regional scale, and because they constitute a possible source of gold and, perhaps more significantly, sulphur for the transport of gold. Prospects in the Conway area are up to 15 km2 in area, and are of the adularia-sericite type. They illustrate many of the classic features (siliceous sinters, alteration mineralogy, and fluid characteristics) recognised in epithermal deposits. K-Ar dating of sericite alteration in three of the prospects has produced a range of ages from 283 to 334 Ma, suggesting that the systems are the product of multiple hydrothermal events.

Jan 1, 1990

By Kyle J. H, Misra V. N

The most recent development in gold processing is the increasing use of heap leaching for the extraction of gold from low grade ore, and old tailings dumps. The reason for this trend is mainly to do with economics. The advantage of heap leaching is the considerable saving in both capital and operating costs. However, not all ores are amenable to heap leaching. It is only applicable to well oxidized ores that have suitable permeability char- acteristics, and the gold recovery is poorer than by conventional process. In this study, an attempt has ben made to ascertain the heap leaching characteristics of Western Australian gold ores on the bench scale using multiple, appropriately sized leach columns. The influence of particle size, flow rate, column depth and leaching time on the rate of gold extraction was determined. The percolation rate of cyanide leaching solution was deter- mined with and without gypsum additions. Efforts were also made to minimise particle segregation, fines migration and solution channelling during leaching, so as to improve solution percolation, gold extraction rate and recovery.

Jan 1, 1991

By Dennis B

The Hilton Mine, 20 km north of Mount Isa was discovered in 1947. The underground mine has been a significant producer from 1989. The long development history is the result of complex orebody geometry, difficult metallurgy, dewatering problems and competition for development funds from the then expanding Isa Mine at Mount Isa. At present it produces 1.4 million tonnes annually. Its 21 million tonnes of reserves are necessary to supplement Isa Mine production.Hilton Mine is located in the Urquhart Shale formation of the Mount Isa Group, within the Mid Proterozoic Mount Isa Inlier. The seven developed orebodies have suffered strong structural deformation. Each orebody has a unique mixture of mineralogy and texture which effects ore value and metallurgical performance. These characteristics have proven useful for correlation purposes.The faulting and folding have caused difficulties with orebody interpretation, geomechanical complexities and has influenced the choice of mining methods: Initial cut and fill and open scope designs have given way to bench mining methods in response to better understanding of the eedloav and economic constraints.

Jan 1, 1993

For decades strip mining with discon tinuously operating 'draglines and shovels has been the most economical operation method in the shallow hard coal opencast mines of Aust- ralia, North-America and some other countries. Continuously operating equipment such as bucket chain excavators and bucket wheel excavators in combination with conveyor belt systems, conveyor bridges and stackers had been deve- loped in Germany; during the last 25 years this type of equipment has been further developed in order to allow a high degree of rationaliza= tion as to opencast mines in unconsolidated overburden in Germany, in many European couh- tries, in India and in Victoria. The differing compactness of the layers to be mined, the increasing mining depth, the adverse over- burden to coal ratio and geotechnical con- ditions account for the combined use of con- tinuously and discontinuously operating equip- ment and systems. This paper is to demonstrate some projects showing the combination of continuously and discontinuously operating equipment which aims at optimizing opencast mine operations. It will be reported on the following combinations: - combined use of bucket wheel excavator/

Jan 1, 1981

In reviewing recent developments in the process mineralogy of gold it is convenient to distinguish between visible (>0.1 pm) and invisible gold (1 - 2 pm in size in polished section; these can scan the surface of a polished section, identifying the gold minerals, recording co-ordinates of the grains for subsequent examination, and making measurements of areas and sizes of the grains. However, problems of sample reliresentivity in polished section mean that such data may not give good quantification of gold mineral proportions and liberation/locking characteristics and other methods are required for this (amalgamation, cyanidation, ultra-fine milling and cyanidation). Characterisation of invisible gold in bulk material (eg a sulphide concentrate) can be done by mineral separation, ultra-fine milling and cyanidation or by quantitative point analyses of a large number of mineral grains. Analytical methods include electron microprobe analysis (detection limit normally -200 ppm but -10 ppm by using special techniques), ion microprobe analysis (secondary ion mass spectrometry - SIMS; detection limit -0.2 ppm) or proton microprobe analysis (PIXE; detection limit

Jan 1, 1992

The paper will review the fundamental policy issues and options that have been considered in the determination of the proposed allocation and pricing (ie royalty) regime for minerals under the Crown Minerals Act 1991. It will consider such influences on the new disposal, allocation, pricing and management arrangements for the Crown's mineral estate as the existence of prior ownership claims, exclusivity in access, the requirement for cost recovery and the treatment of contingent liabilities.

Jan 1, 1993

Thirty mixed cultures of microorganisms from soil, water and mineral samples from the Groote Eylandt Mining Company mine site were approximately three times more effective in biodegrading manganese dioxide (34± 18 mg Mn++/1/day) than sixteen purified strains (11 ± 10 mg Mn++/1/day) isolated from the primary enrichment cultures. Two pure bacterial genera identified as a Pseudomonad and a Bacillus, with an excess MnOz and nutrient, were able to dissolve 106 mg Mn++/litre/day in mixed culture compared with 29 mg Mn++/litre/day when grown separately.

Jan 1, 1983

By M Fahey

Large volumes of tailings are produced annually by the goldmining industry of Western Australia. This material ishydraulically discharged into large storage facilities usingsub-aerial deposition methods. Much of the gold comes fromhighly weathered rock, resulting in tailings with significant claycontents. Consolidation of these materials can be very slow,particularly if occurring under the effects of self-weight alone.To optimise the consolidation behaviour of the tailings, disposalstrategies can take advantage of the effects of evaporation byallowing each tailings layer to dry before the next layer isdeposited. In the last 20 years, much of the gold processing inWestern Australia has utilised saline groundwater. As the salinetailings dry, the surface will develop a thin salt crust. Laboratorytests have shown that these crusts can drastically reduce thesurface evaporation, adversely affecting the behaviour of thestorage. This problem has been the focus of an extensive researchprogramme, with the objective of obtaining a fullerunderstanding of the mechanisms controlling the coupledconsolidation and evaporation behaviour of saline gold tailings.Part of this study involved site investigations of a wide range ofstorages to ascertain their current states. Methods of gainingaccess to the tailings following deposition were developed.In situ testing and high quality sampling were conducted on each storage and samples returned to the laboratory for analysis. These investigations have enabled full characterisation of the storages to be accomplished. Examples of data are shown herein and the implications of the results are discussed.

Jan 1, 2001

By Angove JE, Johnson GD

Sulphide concentrates are produced in a wide range of mineral processing operations. In the case of base metals they are further treated by smelting and/or hydrometallurgical techniques. In the case of refractory gold ores, sulphide concentrates containing gold are roasted or oxidised by various hydrometallurgical processes. This paper discusses the development of the Activox(R) Process which can provide an alternative method for treating sulphide concentrates. This process consists of fine or ultra-fine milling, followed by mild pressure oxidation to produce solutions of base metals or to liberate refractory gold. Base metal solutions (eg of nickel and cobalt) can be further processed by solvent extraction and electrowinning, while refractory gold can be recovered by cyanidation. The economics of the Activox(R) Process are often better than alternative oxidation techniques.

Jan 1, 1993

Removal of Arsenic in Fluorite Ore by Simultaneous Grinding-Leaching with NaHS Generally speaking, a high-grade fluorite ore is converted into hydrogen fluoride (HF), which is essential for the semiconductor manufacturing. With the continuous depletion of resources, novel technologies for processing low-grade fluorite ores are urgently needed, in order to lower the arsenic concentration to less than 100 mg/kg. In this study, a low-grade fluorite ore was upgraded by removing arsenic, which is difficult to remove by conventional method. The mechano-chemical leaching of fluorite ore (i.e. the sample was ground in presence of NaHS, using a beads mill) was carried out to investigate the removal of arsenic from the low-grade fluorite. Experimental results showed that the arsenic concentration was reduced to 73.2 mg/kg.

Sep 13, 2010

A zone rich in-fish debris in the Rolling Dow= Group in the sub-surface of the Great-Artesian Basin has been discovered a Further research has shoe i this zone to-be of very wide distribution in the Artesian Basin and to occur. at the base of the Ta?nbo .f ormati'on resting on the Roma forma-tion. The zone gives a very characteristic curve on the electric and' gamma ray logs and is thus an excellent correlation marker in the sub-surface over a very wide area. It is probably to be correlated sith.the Toolebuc member described from: outcrops east of Boulia. There .are apparent similarities between the Fishecale zone of the Great Artesian Basin in' Australia and the Fishscale sand of the Western Canada Sedimentary Basin.

Jan 1, 1962

Industries in the Kwinana area have embarked on a journey of improving the eco-efficiency of Western AustraliaÆs primary heavy industry area. The Kwinana Industrial Area has some unique characteristics that provide both opportunities and barriers. The Kwinana Industries Council and the Chamber of Commerce and Industry are working with the industries to identify a range of projects that can deliver improvements for both environmental and economic æbottom linesÆ, and to progress these projects using internal and external resources. The evolution of the process, its relationship to the ethos of operating companies, and the availability of resources to pursue projects, is an interesting study with lessons for others interested in taking the same course.

Jan 1, 2002

By J Webb

Anoxic limestone drains (ALDs) have been widely used in the passive treatment of acid mine drainage (AMD), but their effectiveness has often been less than anticipated. Iron hydroxide often precipitates around limestone particles and inhibits neutralisation. To determine the conditions under which iron hydroxide precipitates, a small-scale laboratory ALD system was built to enable a detailed examination of the chemistry of iron within the drain. For one experiment, a mixture of limestone and quartz was introduced to the drain to assist in the determination of the key mechanism governing iron precipitation. Synthetic anaerobic acid mine drainage containing Fe2+ (~130 ppm), SO4 2- and H+ was pumped at a rate of 30 mL/min up a 90 cm tall, 15 cm diameter vertical column filled with limestone gravel of 98 per cent purity. Three sampling ports were fitted at equal intervals along the column; water was periodically extracted for analysis at the sampling ports over an 11-hour period. Experiments were run at influent pH levels of 2 and 4. Results show that acid neutralisation to pH greater than 6 occurred at the inflow end of the drain. The greatest amount of iron precipitation (19.5 per cent) also occurred in this area. The lack of iron precipitation on the quartz surfaces in the quartz/limestone mixture indicates that neutralisation is the key mechanism for the precipitation of iron hydroxide on limestone particles. A pe-pH stability diagram derived for the laboratory ALD system indicates that ALDs will not be effective for AMD with pH 2. Influent waters with pH 2 require a pe of -2 (Eh: -118.4 mV) to avoid Fe precipitation upon neutralisation. Influent waters of pH 4 require a pe between -2 and -4.

Jan 1, 2003

By Tyler DB, Thin LGT

Coal mass strength properties must be estimated to obtain realistic estimates of coal pillar strength. The limitations of existing techniques for approximating these properties are discussed. The coal mass is anisotropic. The Hoek and Brown approach to rock mass property estimation is modified to allow for this. This approach requires the Rock Mass Rating (RMR) for the strata. In the normal case where bedding is sub-horizontal, these major planes of weakness have little effect on the strength of pillars. As a result of this the RMR must be measured parallel to bedding. This means that a significantly higher rating than that usually obtained for coal is observed. The use of mass strength property estimates in extant empirical relationships is outlined. At high width to height ratios, an acceleration in the rate of increase in pillar strength with increasing width to height ratio has been observed. The empirical relationship developed by Salamon (the so called squat pillar formula) takes account of this. This relationship was found to have significant limitations with respect to its universal application. Modifications are made to Bieniawski's empirical formula to extend its use to large width to height ratio (squat) pillars. This new squat pillar formula has none of the disadvantages associated with Salamon's relationship. Strain softening was incorporated into non-linear finite difference numerical modelling to estimate pillar strengths. The technique outlined above is used to obtain peak coal mass properties. Modelled pillar strength was found to be sensitive to both peak and post peak mass strength properties. Post peak properties were found to be difficult to obtain and required some back analysis. Modelling results were used to estimate both the strength of squat pillars and parameters for use in a new squat pillar empirical strength relationship.

Jan 1, 1992

A great range of contacting equipment is used in solvent extraction. However, a tower filled with a regular packing offers many advantages in the direct extraction from slurries. A study was made of the flow of a dense slurry through a packed tower in which the continuous phase was kerosene. The grid type packing, which was preferentially wetted by the slurry, had slats inclined at an angle of 30¦, to the horizontal. On the sur- face of the slats there were uniformly spaced longitudinal indentat- ions. These were of a height slightly less than the film thickness and divided the slurry discharging from the bottom of the slats into a number of uniform streams. When slurry entered the tower it was distributed by means of a troughs and weirs type of distributor. Because of the relatively high slurry velocities that occur at the entry region, it was necess- ary to have the distributor and the first two grids above the solvent level. The interface at the bottom of the tower was located at the mid-point of the bottom grid, so that the slurry entered the interface as a continuous film across the full width of the slats. Using the above system, stable flow with low entrainment was achieved at slurry flow rates of 3.4 mis/cm/sec. This would be equivalent to a flow rate of 177 gallons per minute through a tower of cross-section 4 ft 4 in. by 4 ft 10 in., or 1200 tons per day of solids of specific gravity 2.6 when the pulp density was 65 per cent. Previous tests indicated that a total tower height of about 30 ft would be required for a recovery of better than 99 per cent.

Jan 1, 1969