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By Finlayson E, Hilyard D, Francis G

Papua New Guinea's mainland is dominated by a foreland thrust belt, which can be divided into two zones. The "body" zone is floored by Palaeozoic granites and metamorphics of the Fly Platform (Tasman Orogen). Underlying the "tail" zone is Papuan Plateau, rifted from the Tasman Orogen during Coral Sea spreading, and believed to underlie the Papuan Peninsula and Papuan Islands region (D'Entrecasteaux, Woodlark, Misima, Sudest, and Rossel Islands). Thrusting began in the Miocene and continues today in the crust below the "body" zone. The youngest known thrusted rocks in the "tail" zone are Pliocene in age. Recognition of foreland thrusting has major implications for petroleum prospectivity of the Papuan and North New Guinea Basins, mineral exploration prospectivity, and geological terrane identification in PNG.

Jan 1, 1987

By Fiedler VA, Threadingham GM, Leckenby DF, Clarkson CJ

The Utah Development Company Research and Development Laboratory has embarked upon a programme of optimisation of the company's coal preparation plants. This goal is being accomplished in a three-fold manner - use of pilot plant equipment for optimisation and modelling of the various unit operations, evaluation or development of on-stream ash analysis for process control, and evaluation or development of alternative processes. In each of these areas, digital data acquisition- and at a later stage, process control feedback, is being extensively utilised, based largely upon the use of the HP85 and HP9915 desktop computers. A variety of input/output configurations such as HPIB, BCD, GPIO are used, and at times supplemented by microprocessors such as the Intel 80/05 to assist in data transfer. This paper will discuss a number of specific projects, especially in relation to the manner in which the variables are monitored, and the data later retrieved and analysed.

Jan 1, 1983

The microstructures exhibited by ilmenite in its association with other oxide minerals have been the subject of a number of papers, the most comprehensive of which is that by Ramdohr. The following observations in some degree extend his conclusions. They are based upon a study of about sixty specimens of "massive" ilmenite and titaniferous ores from a number of wIdely 'scattered Australian localities. Specimens of this character proved much rarer than was expected. The collection was gathered together through the generous aid of the University Geological Departments, Geological Surveys, and Natural History Museums of the several States of the Commonwealth, all of which contributed such specimens of local origin, as they possessed. Special thanks are due to Dr. E. S. Simpson, of Western Australia, who made available several highly interesting specimens, together with his...

Jan 1, 1938

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

This paper first describes the essentials of the slurry shield method and its achievements, then problems encountered during driving tunnels and their countermeasures, and finally shows problems to be solved in the future. The author works at Tekken Construction Co., Ltd. as a director. All the data cited are based on material gained from the slurry shield tunneling works undertaken by the said company. The mark, viz*, indicates that Tekken Construction Co., Ltd. has obtained or is applying for a patent in the U.S., Europe and Japan. 1. CONSTRUCTION RECORDS BY SLURRY SHIELD METHOD AND ITS PROBLEMS (1) Shield machines in the future should have the following characteristics; a. to be able to drive less cohesive soil b. to make no change to the ground water table level c. to make it possible to let people work in normal air pressure d. to cause less settlement at the surface To meet the above conditions various kinds of mechanical shields have been are tried, viz. limited air pressure type, rotary cutter with slit regulator, screw-discharge type, blind shield, etc. As far as the author knows, however, they are not 100% successful. Tunnels need their own accuracy in accordance to the usage. Both ease of driving

Jan 1, 1976

By Maiman R

One method of forecasting prices of metals is based on analysis of historic relationships between prices, inventories and consumption. The first, but generally overlooked step in this analysis should be to remove from the inventory and consumption figures the effects of seasonal variations. The next step is to construct diagrams which show prices plotted against ratios of inventories to consumption. These diagrams indicate that, when inventories are high, prices show little response to changes in inventories. Below a critical level of inventories, however, the psychology of the market changes and small changes in inventories lead to large moves in prices. The critical level of inventories is termed the "pinch-point"; the diagram which shows prices in relation to ratios of inventories and consumption may be called a "pinch-point diagram".

Jan 1, 1990

By R Rodriguez, S Gumo

The Lihir Gold Mine, in Papua New Guinea, is a large open pit operation within an active geothermal system inside a collapsed volcanic crater. This unique setting has a big impact on the mine operation because of the occurrence of geothermal hazards. The system for managing geothermal hazards that has been developed by Lihir Gold Mine is a pioneering effort that can be applied to future mine discoveries in a similar environment. The controls are integral to the mining operations and allow mining to proceed whereas without them mining could not be considered. Truck and shovel productivities in conventional open pit operations are constrained by diggability, equipment availabilities and utilisation. At Lihir, additional constraints are in the form of 100 m exclusion zones around working shovels and 50 m exclusion zones around working drills. Given that the mine has seven large digging units and six drills, this amounts to a lot of area that excludes the presence of people on the ground. So how are the necessary work like grade control, survey, blasthole loading, and in-pit maintenance performed safely to achieve production targets? The answer is in the highly specialised procedures that have been developed that utilise geological, geothermal and geotechnical knowledge to predict problem areas and also deal with the organisation of movement in the pit for people and mining equipment. This paper will detail how scheduled material movement can be maintained despite the challenging conditions faced at Lihir Gold Mine.

Jan 1, 2007

By Baafi EY, Chatterjee PK

The quality of mine planning decisions ultimately depends on reliable estimates of the characteristics of the orebody. The quant- ifiable factors such as grades or thickness can be estimated from field data gathered from outcrops or exploratory drillholes. Since outcrop data is necessarily limited to the periphery of a deposit, extensive drilling generally is required. This paper outlines a method for selecting the number and location of additional exploratory boreholes using an iterative procedure based on a mathematical optimization concept called fixed point theory. The method is illustrated through its application to an exploratory drilling program for a coal mine where optimized locations gave a lower estimate of regional and block variances than a manual Choice.

Jan 1, 1986

By Thornton D, Esterle J, La Rosa D

Control of blast fragmentation has a significant impact on coal mine profitability. Two approaches for the characterisation of coal blastability, particularly in terms of fines, are presented. Both approaches were implemented for the predictio

Jan 1, 1998

By Bailey S, Avraamides J

Laboratory-scale experiments were conducted in a mechanically stirred aeration vessel to determine the rusting abilities of aerated water in the presence of various catalysts compared to the industrially used ammonium chloride. The catalysts used were tartaric acid and citric acid, firstly by themselves, and then in later experiments mixed with ammonium chloride. From these experiments it was found that leaching of iron from reduced ilmenite in the presence of either tartaric acid or its sodium salt was much slower than in the presence of ammonium chloride. Citric acid or its sodium salt also give a slower rate of leaching than the ammonium chloride system, but citric acid and its sodium salt mixed in equal proportions produced a rate of leaching approximately twice as fast as the standard ammonium chloride system. When tartaric acid was mixed with ammonium chloride the leaching rate was found to be equivalent to the leaching rate of the same amount of ammonium chloride alone, thus indicating that tartaric acid made no contribution to the leaching in this svstem_

Jan 1, 1996

By Koh P. T L, Varnas S. R

Fluid flow, heat transfer and combustion in a nickel flash smelter have been investigated by numerical modelling and flow visualisation. The three-dimensional numerical model incorporates turbulent two-phase fluid dynamics, radiative heat transfer and combustion. The main features include the use of the k-E turbulence model, the Lagrangian tracking of particles, radiative heat transfer based on the spherical harmonics method, and chemical reactions. The predicted flow fields are in good agreement with data obtained from a series of flow visualisation experiments on a cold water model. The interaction mechanism between the fluid flow and the solid particles is examined for a range of particle sizes both with and without injected oil in a series of simulations. The heat transfer in the shaft is dominated by combustion and radiation, whereas the ignition of particles is influenced by the particle size and the added oil. Flow and temperature fields for both gas and solid particles are presented as well as the fraction of sulphur removed from the particles.

Jan 1, 1992

A nine-month investigation was conducted into the effect on coke quality and blast furnace operation of the addition of bentonite and southern coal to the northern coal fed to the coke ovens at the Newcastle steelworks.Additions of 0·3 per cent bentonite or 25 per cent southern coal to the northern coal increased the coke strength from 15-20 A.S.T.M. stability to 25-30 A.S.T.M. stability. It is likely that improved mixing and blending facilities would, in both cases, give a coke of over 30 A.S.T.M. stability.For the same coke strength, the use of 0 3 per cent imported Wyoming bentonite was considerably cheaper than the use of 25 per cent southern coal, but the use of Australian bentonite promises the same coke strength for still lower costs. Other additives such as coke breeze, charcoal, iron ore fines, and certain other finely divided materials, gave relatively minor improvements in coke quality.There appeared to be sufficient improvement in blast furnace operation and production to justify full scale addition of bentonite to improve coke quality, although other variables, particularly iron ore physical quality, overshadowed on many occasions the effect of coke quality. Further coke trials with southern or bentonite will be carried out when ore quality has been improved by the introduction of ore sintering at Newcastle.INTRODUCTIONDuring the period of operation of the Newcastle coke ovens and blast furnaces from April 1960 (when No. 3 blast furnace was blown in after rebuilding) to December 1960, a bentonite coke trial was carried out based on earlier research findings (Gregory, 1959a, 1959b; Felton and Gregory, 1960; Gregory, 1960) that as little as 0 3 per cent to 05 per cent bentonite clay added to northern N.S.W. high volatile coking coals gave a significant increase in coke strength. The bentonite coke trial was followed by trials...

Jan 1, 1962

Quite often the reserve assessor becomes enamored with the numbers gen- erated and forgets the basis for his assessment. The quality of the assess- ment can only be as good as the quality of the input data. The use of seismic data from the Gippsland Basin in assess- ing Esso/BHP's oil and gas reserves is an excellent example of this principle. By significantly improving the quality of seismic data, a much more reliable estimate of a field's reserve potential can be made. In addition, it provides the basis for further delineation drill- ing which, as recent experience in Gippsland has shown, often leads to increased reserves.

Jan 1, 1979

By Renwick MT

Two innovative ground reinforcement products have been developed for use in the mining industry. One of these products is a high strength polyethylene (HOPE) bar for use as a rib bolt in underground coal mining and as a corrosion proof tendon in open pit mines. The other product is a cable bolt (Ultrastrand) which demonstrates enhanced load transfer and is available in continuous lengths. Ultrastrand's exceptional in- situ performance and versatility makes it ideal for mechanised installation in both underground and surface mining operations. Details of these products are presented and results from labortaory and field trials are discussed.

Jan 1, 1992

The effect of accurate detonator delay timing on blast results can now be studied with the development of the ICI Electronic Detonator. This detonator has an accuracy and precision orders of magnitude greater than the current range of pyrotechnic delay detonators. A series of field trials have been conducted to quantify the effect of delay accuracy and timing on blast performance. These trials have demon- strated that delay timing can have a marked influence on blast fragmen- tation, muckpile displacement, blast vibration and airblast.

Jan 1, 1989

By Lyman GJ

Systems for the routine on-line determination of ash content of process streams in coal preparation plants and handling systems have been in use in Australia for over four years. More recently, monitors for on-line moisture measurement have been developed to complement the ash measurement function. The technology for these systems is reviewed briefly. The development of reliable ash and moisture monitors has made the implementation of automatic systems of coal quality control practical. The emerging philosophies of automatic control in Australian preparation plants are examined with particular emphasis on systems involving dense medium circuit regulation. Related developments in flotation control and coal sorting are noted to complete this overview.

Jan 1, 1987

By Takiuchi T, Kurita M, Owada S

This paper describes the possibility of the application of flotation to the separation of monazite from xenotime and of columbite from ferberite, which have been said to be difficult with generally used physical beneficiation methods. For Malaysian monazite and xenotime samples, a great difference is observed between the flotation recoveries at pH 7.5 using 1.0 x 10-4mol/1 dodecylammonium chloride (DAC). The grade and recovery of columbite in the binary flotation with both minerals result in 85 per cent and 67 per cent in the cleaning froth and 91 per cent and 51 per cent in the re-cleaning froth, without adding any scavenging stages. For monazite samples from various localities, the flotability is dominated by the electrostatic interaction between mineral surface and collector ion using DAC as collector, but the singular decrease of flotation is observed in the sample of which the crystallinity is low and the surface structure is rugged and complex. Otherwise, ferric ion in the flotation system probably dissolved from mineral is found to activate the flotation using sodium dodecylsulfate as collector. For columbite and ferberite, the separation is judged possible at pH 3.0 using 1.0 x 10'3mo1/l sodium oleate (NaOl) from the single flotation results of each mineral. In the binary flotation, however, columbite recovery in the froth is greatly diminished below that expected. This would be because NaOl is prevented from adsorbing on the columbite surface of which the charge is transformed more negative side by the specific adsorption of the tungstate ion dissolved from ferberite.

Jan 1, 1993

By Jorgensen FRA, Moyle FJ, Turner TM

Laminar flow furnace techniques and thermal analysis were used to study the combustion of Kambalda nickel concentrate and Collie coal. The study was made to ascertain the suitability of the latter as a replacement for the fuel oil currently burnt in a flash furnace at the Kal- goorlie Nickel Smelter. The coal was found to ignite at temperatures between 500-600¦C which was the same as that required for the most reac- tive component of the concentrate, namely py- rite. The rates of reaction of both the coal and concentrate were dependent on oxygen con- centration. Sulfur dioxide hindered the combus- tion of concentrate and of coal, the effect on the concentrate being the more pronounced. The effects of moisture content and the tendency for spontaneous combustion of the coal were also noted.

Jan 1, 1982

By Sengstock G. W, Spathis A. T

Benchmarks of mine equipment involved in the excavation process of coal mines would suggest that such equipment is not always operating at an optimum level. Dragline operations and truck/shovel operations rely on efficient use of their plant in order to maintain high mine throughput. The first process which affects the material to be excavated is the drilling and blasting process. Drilling and blasting delivers a fragmented material with a given disposition ready for excavation by mine equipment. As mine operators demand more productivity from their major excavating equipment, many sites are considering the use of productivity monitors to measure their outputs. Some of these productivity improvements will be directly related to the drilling and blasting process, so that as the monitoring systems improve, the opportunities to evaluate all drilling and blasting variables will also improve. This paper reviews current and newer methods for monitoring equipment productivity in mines. These include simple time and motion studies obtained by either manual timing of processes or by automated data collection equipment being adopted by the industry. Case studies for truck/shovel operations are discussed and the productivity improvements are compared with typical industry standards. These improvements relate specifically to parts of the load, haul and dump cycle and the potential for significant improvements are identified. Particular opportunities for drilling and blasting improvements are also presented.

Jan 1, 1995

Oxygen is required for the leaching of gold ores in cyanide solutions. The source of this oxygen demand and the effect of dissolved oxygen concentration on the rate of the process are briefly reviewed.A method of measuring the oxygen consumption rate is described and some experimental results reported.Fundamental aeration theory and rating of aerators is summarised to show how this type of experimental work provides the basis for full-scale design of aeration equipment.

Jan 1, 1984