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The crushing and concentration of ores, as Herbert Hoover commented in a footnote in De Re Metallica, stretches back at least 6000 years. During those years there have been continuing changes and improvements in mineral processing technology. It has expanded greatly in its ability to handle different types of minerals, and lower grade and more complex ores. Australia will be dependent on the mineral industry for the fore- seeable future and there will be continuing demands on the mill opera- tors to improve the technology with regard to efficiency, flexibility and costs. These demands will be met successfully in the future as they have been in the past. This Mill Operators' Conference is an important forum for assessing our present position and planning for the future.

Jan 1, 1988

Maximising margins in highly competitive international markets demands superior productivity. A key to superior productivity is using a process approach to enable rapid, ongoing improvement of production, commercial, administrative, marketing

Jan 1, 1998

By Fitzpatrick JM

The feed preparation section of the Whyalla iron ore pellet plant includes a screening and crushing plant followed by dry grinding mills. Improvements in the efficiency of the vibrating screen and cone crusher have enabled screening plant throughput to be increased and product size to be decreased. This, in turn, has enabled improvements in the grinding mills' operation.

Jan 1, 1978

Cut and fillstoping using hydraulically placed mill tailings has become an essential feature of stoping operations in Kalgoorlie. ' Approximately 30 per cent of the total production is currently mined by this method. Fill is prepared by thickening or cycloning and is gravitated or pumped underground. The average pulp density is 70 per cent solids by weight, Recent cost reducing innovations are the use of steel passes, corrugated iron manways, polythene film sealing, and the replacing of vertical cement lined pipes with boreholes. TTTTTI rvr T Trim r l1TT

Jan 1, 1964

A test model is presented for the simulation of dewatering by gas injection of a porous aquifer above longwall workings. A finite difference model used in the oil industry was modified to match the underground mining conditions. The model is suitable to cope with the problem of dewatering reservoirs of low transmissivity. After comparing more versions, it has been concluded, that the investigated dewatering method can be proposed under special hydrogeological conditions only.

Jan 1, 1988

Although a small quantity of lc,;v viscosity index ' (L.V.I.) oils are presently manufactured in. Australia, lubricating oil refining methods are assuming gxeater significance since in 1964 Australia will be locally refining the bulk of its requirements and some companies may be exporting a surplus. New plants are ' planned to refine mainly high and medium viscosity index oils from imported crudes and the paper describes typical techniques used òto: produce. thes& oils. .

Jan 1, 1962

By E Villaescusa

This paper describes a methodology for the design of mine pillars at the McArthur River Mine. The pillar strength is calculated using a method that accounts for confinement, pillar geometry and intact rock properties. The average pillar stress was calculated using in situ measurements of vertical stresses at shallow depth and the tributary area method in conjunction with numerical modelling. Observations of pillar behaviour indicate that an existing pillar stability graph may be slightly conservative and further adjustments for the local rockmass conditions are needed. The results to-date indicate that all mine pillars are stable for a range of mining geometries at McArthur River Mine.

Jan 1, 1998

By L R. B M Sß

This paper presents the results of a liberation study made on a sulfide copper ore from Carajßs, Brazil, in a mini pilot plant flotation test. The aim of the research was the methodological evaluation of a liberation study using a sample crushed at 1 mm and a sample ground for flotation testing to a target size of 80 per cent

Jan 1, 2005

By Toomey P. T

In many open cut coal mines, rivers and large creeks can cause planning and operating difficulties, both in the terms of the more obvious location of the current watercourse, but, and sometimes more importantly, past meandering of the watercourse. Prevent and past flow regimes may have deposited large alluvial sequences within the current mining areas. The presence of groundwater within the alluvium further complicates the planning and operating practices.A situation exists at Saraji Mine in which alluvial sediments overlie a massive sandstone sequence which in turn lies at about one metre above the coal seam. The problems encountered include high levels of groundwater ingress to the pit, highwall instability, and an unacceptably high rate of blast hole collapse (prior to charging with explosives). Other aspects of the dragline stripping operation were also affected.

Jan 1, 1992

By A J. MacDonald, M P. Raffield

The South Deep massive orebody consists of 20 to 30 m of payable conglomerates ranging in dip from 11¦ to 20¦ and at depths of between 2400 m and 3400 m. The mine design process selected a mining method with a proven record of application that could be adapted to overcome the inherent difficulties associated with the depth, thickness and structural influences of the South Deep orebody. A modified cut and fill mining method provides a concentrated and highly flexible method of extraction. An integrated destressing cut will enable the modification of the stress environment such that it is suitable for massive mining operations. The choice of backfill type and stoping width in the destressing cut ultimately determines the characteristics of the stress modification and, as such, is critical to the success of the cut and fill operation. This paper discusses the decision process undertaken to determine the optimum backfill type and stoping width combination in terms of, conditions in the destressing cut faces and in the massive mining environment. Numerical modelling has been extensively used to analyse various scenarios to aid in the decision process.

Jan 1, 1998

Reconnaissance geochemical exploration in the vicinity of low angle detachment faults which bound the core of the Paparoa metamorphic core complex yielded Au up to 14 ppm, with 35% of greywacke, granitoid and quartz vein samples in the northern range exceeding the 0.01 ppm detection limit. Au is associated with Ag, As, Sb and Cu anomalies consistent with epithermal-type mineralisation. The Ag and Cu anomalies also distinguish this mineralisation from older, mesothermal Au deposits widespread in the Ordovician 'slate belt' greywackes, which comprise much of the upper plate of the core complex. Baryte, molybdenite, fluorite and stratiform U mineralisation in the northern Paparoa Range may also be related to hydrothermal activity along the detachment fault zones.

Jan 1, 1995

The Coke Ovens Laboratory at Australian Iron & Steel, Port Kembla has been involved in the analysis of seam gases and mine airs for approximately twenty (20) years. This period has seen many developments and changes in the techniques used to the point when the current techniques are equal to other labora- tories involved in similar analyses. The laboratory has NATA registration for the analysis of mine airs and gases. Apart from routine testing of seam gases, ventilation airs and gases emmitted from coal bore cores a number of projects have been undertaken. These have served a twofold purpose, one to provide information to the customer, generally Collieries Research and Technology and secondly in developing the skills and capabilities of the Coke Ovens Laboratory. This paper discusses the development and services available at the Coke Ovens Laboratory for the analysis of gases and airs from collieries.

Jan 1, 1983

In epithennal deposits changes in the character of mineralization in depth and time are conspicuous and abrupt at the interface between supergene and hypogene zones. As the reaction zone migrates downward as a consequence of surface erosion, previously deposited minerals are placed in unstable chemical enviromments and dissolved. This reaction takes place at the base of the epithermal precious metal zone. Examples at Cerro de Pasco, and Casapalca, Peru; Carlin, Nevada; and porphyry copper-gold deposits are cited.

Jan 1, 1991

By Taylor RN

A simple apparatus for delivering pulverized coal as fuel to a SIROSMELT lance is described, and its performance in smelting tests is evaluated. Using the pulverized coal as fuel, the SIROSMELT furnace performed well in both oxidative copper smelting and reductive smelting (zinc fuming). In both cases the evidence suggests that part of the combustion occurred by indirect oxidation of coal particles entrained in the bath. Oxygen potential measurements made during the zinc fuming tests confirmed the general features of the the non-equilibrium mechanism for zinc fuming proposed by Richards and Brimacombe. The zinc level in the slag during continuous fuming was lower than was predicted using an equilibrium model.

Jan 1, 1987

By Johnson CR, Wilkie G

The aim of the study was to use quantitative mineralogical measurements to predict the processing characteristics of an ore. Samples were taken from a wide range of concentrators processing ores of lead, zinc, copper and nickel. QEM'SEM was used to measure the characteristics of the ore feeding the plant. Concentrate product samples, together with plant operating data were used to give concentrate grade, recovery and grind size information. It was found that the mineralogical measurements correlated well with the metallurgical parameters indicating that these techniques will be very useful for making predictions in feasibility studies and simple plant optimization.

Jan 1, 1989

By Phillips H. R

The action of free rolling disc cutters is well understood, relationships between disc geometry and performance having been established both in the laboratory and under field conditions. However, under severe operational conditions a malfunction of the disc bearing assembly is likely to produce a definite change of cutting action. Collapsed or siezed bearings can even prevent the disc from rolling and thereby create what is equivalent to a drag pick. This paper describes a programme of laboratory experiments using deliberately stalled discs. Their performance under such conditions is contrasted with that for a free rolling disc and also with a drag pick having a ridged front developing into a negative radiused back clearance angle. In conclusion an assessment is made of the influence stalled discs can have on the torque and thrust requirements for a tunnel boring machine.

Jan 1, 1981

The facilities used and techniques employed in the manufacture of steel and iron rolls at the Steel Foundry, B.H.P., Iron & Steel Works, Newcastle are described.

Jan 1, 1972

By Ross T. J

Renison Limited operates an underground tin mine employing both cut and fill and open stope methods, at Renison Bell on the west coast of Tasmania. Mining in the region commenced in the 1890's. Development of the current mining operation commenced in 1965. The ventilation system used at Renison in its present configuration is a function of current mining methods, orebody characteristics and prevailing Tasmanian Department of Mines Inspection Regulations.

Jan 1, 1988

By T Ueda an, T Sasaoka, A Yabuki, H Shimada

The basic concept of auger mining is to extract coal beyond the economic limits of surface mining technology by drilling holes of an appropriate diameter size into the exposed seam of the highwall as deep as is technically, economically and operationally feasible. This method of mining is used at the final highwall of typical surface mining operations. This paper describes the auger mining systems and discusses the methods to increase the coal recovery in auger mining from a field trial in Australia.

Jan 1, 2003

Two main aspects need to be considered when analysing a potential petroleum development project. Firstly, an estimate of the recoverable reserves must be made, and in many instances, these reserves must serve as collateral to finance development if outside capital is required. Secondly, the likely production profile and cash flow has to be established, and this cash flow then must meet debt service require- ments and in addition generate the required profits. In making these crucial deter- minations, the impact on the project of a wide variety of risks has to be analysed. A computer model, which represents the project in its entirety, is a great aid in determining project viability. Such a model requires imput from geologists, engineers and economists, and interpretation of the model must also be a joint effort. Communications, and inter react ion amongst individuals and disciplines is essential if the best answers are to be obtained

Jan 1, 1983