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By R H DAVIES

Peak Gold Mine is a new gold and base metal mining project being developed by Enterprise Metals (a 100 per cent subsidiary of CRA) at Cobar in the centre of New South Wales. The Cobar district has a long history of copper and gold mining operations stretching back to the 1870s. Extensive gold and base metal mineralisation was discovered at the Peak in 1981 below a series of gold mines which had been active around the turn of the century. Evaluation of the deposit through the 1980s led to CRA's decision to develop the project for production at a capacity of 450 000 tonnes per annum in late 1992. The project has been developed with a green fields approach despite the long history of mining in the local area. This approach has lead to several innovative ideas being trialed at the site which are expected to result in the operation being a low cost producer of gold and base metals.

Jan 1, 1992

The primary object of this paper is to describe the present metallurgical practice of the Emperor Combined Mill, wherein ores from the adjoining and Associated Mining Companies, Emperor Gold Mining Company Ltd., Loloma (Fiji) Gold Mines, N.L., and Dolphin Mines, Ltd., are treated for the recovery of gold and silver.The mining field is located in the foothills, five miles from the sea, on the northern side of Viti Levu, the largest and most important island of the Fiji group.The orebodies occur in basalt and associated ash beds overlain by andesite, tuffs and sediments. The basalt is a dark greenish-black rock and in much of the ore mined is weathered with alteration of the olivine to serpentine and iron oxides, of the augite to chlorite and of the minute included crystals of iron ore to other iron oxides. Into the basalt intrudes a considerable number of andesite dykes, and the lodes occur as veins in these dykes, as "flatmakes" along fissures or, ash beds extending horizontally from the dykes and at the contact of the basalt and the andesite dices.The Emperor orebody is the largest and most important, and consists essentially of massive, shattered, well altered and mineralized basalt.Little or no free gold occurs in the ore at present being milled, the most important host minerals for gold being the tellurides sylvanite and hessite, next in importance being the sulphides, pyrite, marcasite and arsenopyrite. Chalcopyrite is present in quantities large enough to be troublesome in the subsequent concentrate treatment section, while sphalerite, tetrahedrite, bornite, galena and native tellurium are present in small quantities.Unimportant occurrences of native copper have been observed in both Dolphin and Emperor orebodies.

Jan 1, 1953

FOR some reason there is not any extensive literature in print on the electrolytic refining of copper, although the method is in general use in America and Europe. In Australia there are but three plants in existence one small one at Wallaroo, in SouthAustralia; one at Lithgow and one at Port Kembla the last two being in New South Wales. The largest of these is the Port Kembla plant. It is also the most modern, and embodies all the latest appliances and improvements of electrolytic practice.The plant and methods about to be described is that at Lithgow, with which the writer was associated for some years, and the experience gained there may be of interest. Electrolytic refining of copper is one of the simplest operations of metallurgy, but, like all metallurgical operations, it requires constant attention and a large amount of common sense. The man in charge should be endowed with an insatiable curiosity as to why certain things are occurring, and an instinct of cleanliness, whichmy first mentor in chemistry, Mr W A Dixon, once impressed on me was better than godliness.

Jan 1, 1911

The approach to this subject is a very general one, but an attempt has been made to cover briefly a very wide field in the nationally important job of manufacturing iron for the iron and steel industry.Some historical data concerning the development of the furnace itself from early days have been followed by the modern ideas on raw materials and their beneficiation. Recent furnace design and modern auxiliaries have been given attention with, finally, some developments in practical operation.HISTORICALWhen dealing with such large 'and costly operating units as blast furnaces, there is not the same opportunity for research in design as in most other metallurgical processes. Over past generations the development of furnace design, or "lines" as it is usually termed, as well as most radical operating changes, has been very gradual.However, there have been some periods of rapid progress due to revolutionary changes. One such was the adoption of the steam engine for blowing and charging operations, and also, during this same era, about 1750, coke was first used as fuel in place of charcoal. Another revolutionary change came some 100 years later, when heating the blast became usual practice.Since then there have been great improvements in mechanical equipment and in the preparation of raw .materials. These factors, together with a better understanding of what happens inside the furnace, have led to the development of those large mechanically operated structures which are the most modern in blast furnace design.For many, years America has led the world in pig iron production and in furnace development, so that American design and practice is now recognised almost as standard. This type of furnace replaced the older stacks in England, Russia, Germany, South Africa and India, as well as here in Australia.

Jan 1, 1947

By Kilgour I

The installation of a final cleaning column at Ok Tedi Mining Limited was carried out to increase final concentrate grade in order to reduce concentrate handling, shipping and treatment charges and to reduce penalty payments. To fast-track the project a decision was made to install a full-size column on one of the two parallel circuits, designed on information readily available and utilising the experience of mill staff and an engineering consultant, rather than delay installation while a pilot scale program was conducted. A 3.66 m diameter by 12.8 m high column was installed to produce 40 t/h of final concentrate from a combination of rougher concentrate and recleaner concentrate. The column design and sparger system were by Cominco Engineering Services Limited.

Jan 1, 1991

By Stitt P. H

This paper provides a brief historical review of the invention of the spiral separator and its adoption into Australian metallurgical practice. The purpose of the review is to demonstrate that spiral development to date appears to have been a largely empirical process, and that the cur- rent resurgence of interest in the spiral, especially in the coal industry, warrants an increased fundamental research effort. Current research work concentrating on empirical modelling is outlined, while some preliminary experimental results of a more fundamental nature are presented and some research of other disciplines interested in particle transport introduced in order to stimulate further work and discussion.

Jan 1, 1988

By Fraser CJ

Stability control plays a prominent part in the planning and execution of coal winning in the deep open cuts in the Latrobe Valley operated by the State Electricity Commission of Victoria (SECV). Different stability mechanisms affect the individual overburden and coal faces. These are the classical rotational slip in overburden and the three-dimensional tetra- hedral wedge or planar block slip in the coal faces. The stability of the overall batters is affected by the so-called "block sliding" mechanism, which is unique in Australian open cuts. The basal stability of the open cuts is affected by pressure from water in confined aquifers underlying the coal being excavated. This paper describes each of these mechanisms and the current monitoring and con- trol techniques practised by the SECV.

Jan 1, 1982

By S Gannon, J Abols, T Hughes

In the past year, two very innovative gold ore processing plants have been designed, built and commissioned by Gekko Systems Pty Ltd. The first plant in Vietnam utilises conventional crushing and ball milling followed by gravity concentration (Inline Pressure Jig (IPJ) and Falcon concentrator), flotation, intensive leaching (GFIL), the first industrial scale use of AuRIX«100å ion exchange resin and a cyanide destruction circuit. The second plant, in Australia, uses a three-stage crushing circuit to crush the gold ore to minus 1 mm, followed by gravity concentration utilising a rougher, scavenger, cleaner circuit of IPJs and a Falcon concentrator. A direct smeltable gold concentrate is produced as well as a lower grade concentrate for future intensive leaching or sale. Both plants were designed and built within very tight time frames and budgetary constraints. The experience gained during the plantsÆ design, commissioning and operation are discussed.

Jan 1, 2006

By Cortes JP

In a dynamic environment such as the Star Mountains of Papua New Guinea Geotechnical Engineering for the Ok Tedi Project must be described as both interesting and challenging. To be effective a reasonable sized team of dedicated people is required with occasional supplementation by specialist consultants and an annual review process. Ok Tedi Mining Limited's (OTML) Geotechnical Section has a vision to be recognised as the leading mine-based geotechnical engineering section in PNG and to be world class by any international standards. This paper deals with the organisational and operational duties of the Geotechnical Section at the Ok Tedi Mine. One of our major roles is in the area of safety, and in particular in the early warning of natural and mining induced geological hazards that may affect safety and/or productivity. The major activities in- clude geotechnical inspections (pit, waste dumps, tunnels, re- gional), data collection activities and database management, geotechnical design and control work.

Jan 1, 1997

By Ohga K, Isobe T

Basing upon many and long practical experiences of gas drainage from coal seam and results investigations on the gas flow through in si-tu coal seam using tracer gases,it became clear that solid coal itself is hardly gas permeable or has extremely low gas permeability. Almost all of gas flows from a coal seam into boreholes through fracture net- works intersecting with them.Primary and secondary fractures in coal seams differ in their size and continuity from place to place according to differences of the coal strength and the stress conditions. A lot of gas can be drained through boreholes which intersect with many and/or wide fractures. A mathematical model for gas flow from a coal seam to a borehole through a discoidal fracture is proposed. From the numerical analyses,the apparent radius of the discoidal fracture in this model is shown to be a good indication of the gas drainage ratio. In addition to this,an atempt to make fractures around a borehole using high velocity water jet(ca.lmm dia.,300-700atm., 100-200 1/min.) is introduced.

Jan 1, 1982

By Beattie MJV

Widely diverse mechanisms exist for the action of a range of selective sulphide flotation depressants. Collector desorp- tion, leaching, competitive adsorption, formation of hydrophilic reaction-product coatings, action as reducing agents, and action as lattice-oxidizing agents are discussed. Detailed attention is focused on the latter two mechanisms. Recent works on copper depressants particularly for copper-molybdenum separations, and oxidizing agents enabling arsenopyrite- pyrite separations, are presented and discussed.

Jan 1, 1984

By Sauer P

The features of Banana screens have been known for some considerable time and recently considerable interest has been generated in the performance of these units. This paper reviews screening principles on Banana and conventional units and demonstrates the capacity and effic- iency of these units. Furthermore, the behaviour of modern Banana screens and modem screens in general, are examined with respect to life, vibration isolation, noise emission and maintenance requirements.

Jan 1, 1978

By J J. Campbell, G J. Wilkie

The ores of the Golden Mile exhibit considerable complexity. As a consequence, the operating company, Kalgoorlie Consolidated Gold Mines (KCGM), considered it important to develop a coherent database of information describing the nature of the many ore lodes in terms of (1) rock properties and mineralogical content, including relative proportions, grain size, associations and deportment of key elements between minerals, (2) the relative behaviour of consituent minerals in various stages of processing and (3) the nature of the final products and key intermediate streams. The paper describes a sequence of metallurgical tests covering comminution, flotation, gravity concentration, leaching and calcining, carried out on three lodes of the Golden Mile. Key samples generated by the testing were subjected to comprehensive size-by-elemental assaying and QEM*SEM mineralogical determinations of sulphide and precious metal associations. Significant differences between lodes were identified, and the impact of these differences on processing is discussed.

Jan 1, 1998

By Toivanen R-M, Leinonen O, Pekkarinen H

This paper presents developments in designing an integrated mine control system at Kemi mine. The aim of this paper is to present the general structure of the system and to outline some features of the process control strategies. The results o

Jan 1, 1998

By Maidl B

A tunnel operations analyser is a new high technol- ogy instrument for use in underground work. By remotely sensing the acoustic emissions from operating machines and processes in a tunnel or shaft and by applying sophis- ticated computer processing to them individual process cycles and other detailed information about the operating processes can be collected. Detailed analyses and dissec- tions of the work in progress can be made and a variety of action oriented management reports produced. The pro- cess is fully automatic. Results of applying this device to two full scale tunnel projects are presented. The hardware and software that comprise the instrument are discussed in detail. Processes by which this device can be used to sub- stantially reduce tunnel costs are presented. It is concluded that this type of technology has great potential.

Jan 1, 1987

By Lawson F

Synthetic calaverite (Au Tez) has been prepared and its physical properties checked.Simple flotation tests indicate that the recovery of calaverite should be possible using n-butyl or sec-butyl xanthate collectors under approximately pi I neutral conditions with a copper sulphate activator.Roasting calaverite in air at moderate temperatures resulted in its decomposition with the formation of elemental gold and tellurium dioxide.In alkaline oxygenated cyanide solutions, both gold and tellurium tend to dissolve. At pHs less than 14, about 50 per cent of the tellurium remains as elemental tellurium; however in very strongly alkaline solutions, essentially all of the tellurium is converted to the soluble tellurite ion (TeOl-).However, even at high pHs, the solubility of gold in the cyanide solution is still low due almost certainly to passivation effects.

Jan 1, 1991

The Gympie Province is a unique tectono-stratigraphic unit which does not fit into the overall palaeogeographic pattern of the New England Fold Belt (NEFB), and part of it has been proposed as an exotic terrane more closely linked to New Zealand. From E to W the Gympie Province comprises 6 distinct units which can be evaluated as suspect or exotic terranes.

Jan 1, 1990

By Nilmani M, Fountain CR

Injection of gases into slag-melt mixtures produces various zones as a result of bubble formation and disintegration within the melt. The extent of these zones depends on the type of reactor used. When compared with ferrous processes, non ferrous processes are character- ised by large bubbles formed adjacent to the tuyeres, low flowrates and shallow tuyere sub- mergence. These features can result in a greater proportion of reaction occurring above the bath, more refractory wear and tuyere blockage with more splashing. The large bubble zone adjacent to the tuyeres has been investigated using the tech- niques of physical modelling, mathematical modelling and plant trials. Large bubble form- ation in physical models was recorded using a high speed camera and a rapid response pressure transducer coupled to an oscilloscope and data recorder. It was found that the bubble volume (Vb) could be correlated at low flowrates using the single bubble model Vb = 1.378 Q6/5 g-3/5 Deviations from this correlation occurred with increasing gas jet momentum. Plant trials were carried out on a copper converter at Mount Isa Mines during five different charges. Pressure measurements were made through the tuyeres during the slag blow and commencement of the copper blow. The power spectrum density showed that the dominant pulse amplitude occurred at a frequency of approximately 3 pulses/sec. Plant data from this and other converters were correlated using the same relationship as for physical modelling. De- viations occurred due to the state of the re- fractory, bath composition or bath circulation effects.

Jan 1, 1984

The Circum-Pacific area is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands skarn deposits of different types. According to the differences of major metallic elements, the skarn deposits may be classified into seven subtypes, i.e. Fe, Cu, Pb-Zn, W, Sn, Mo and Au skarn deposits. In this paper, the distribution. and geological characteristics of above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types: magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with Fe, Cu, Au,, Sn, B, Be mineralization, calcic skarns with Fe, Cu, W, Mo, An, Be, Pb, Zn, Sn minerailization, while the alkaline skarns occur in U(Th, Nb) deposits. The skarn deposits of both East and West Pacific rims have many general characters, but have some diferences in geotectonic settings, intensities of mineralization, distribution, and metallogenic epoches. In this paper, the minerogenetic series and the mineralizing specialities of related magmatic rocks of the skarn deposits are also discussed.

Jan 1, 1990

Effective pre-splitting is a key feature of wall control blasting. Most mining operations use historical designs or rules-of-thumb for designing pre-split blasts. If productivity and safety benefits are to be gained, these methods need to be improved in order to accurately predict pre-split performance. This will become more pertinent as overburden depths increase, placing more demands on the pre-split operation. A classical qualitative quasi-static description of pre-splitting (Kutter and Fairhurst, 1968) is presented and it is shown to give some useful insights into the pre-splitting process. In particular, it is clear that the time interval between the initiation of adjacent pre-split holes is a very important factor. In terms of this analysis, it is shown that current techniques which employ detonating cord as the surface initiation system are not optimal. A static quantitative model for pre-split design which has been widely reported is then discussed and its simplifying assumptions and their implications are examined. It is shown that several of the assumptions may be reasonably justified in the light of real pre-split results. It is concluded that the model should yield conservative designs. For this model, the key calculation of the blasthole pressure that is needed to determine the required explosive charge is highlighted. Popular methods employed in the literature for describing the expansion of real detonation products are shown to be inappropriate and an alternative method using the non-ideal detonation code, CPeX, is proposed.

Jan 1, 1995