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By Mur D. M

Metal ferrites are formed by the high temperature reaction of various metal oxides with hematite and are commonly found in the calcines derived from the sulfation roasting of zinc, copper and nickel sulfide concentrates. The Jarosite Process is designed to treat such zinc ferrites by hot acid dissolution but little information is available on the basic reactivity of various ferrites and the effect of Eh. As part of an overall study of the reactivity of calcine products from copper and nickel sulfide concentrates it has been found that Eh plays an important role in the rate of dissolution of magnetite, hematite and nickel oxide by HC1 and H2SO4. Further studies on the reactivity of pure synthetic copper,zinc,and nickel ferrites also show a dependence on Eh. This paper discusses the relative reactivity of iron oxides and metal ferrites in 1 M HC1 and the results of electrochemical studies using cyclic voltammetry. A mechanism for the dissolution reaction is proposed as well as factors which determine their leaching. It is shown that the rate of leaching of metal ferrites with HC1 is enhanced in the presence of reducing agents such as Cu(I) and Sn(II). By contrast the leaching of NiO is enhanced by oxidising agents such as Cu(II).

Jan 1, 1987

The City of KalgoorlieBoulder is situated approximately 600 kilometres to the east of Perth, and as the major regional centre of the Eastern Goldfields, supporting a population of approximately 25 000. The formation of Kalgoorlie Consolidated Gold Mines in 1989 brought the existing operating entities adjacent to the city under common ownership and management. The Joint Venturers forming the management company are Homestake Gold of Australia and Gold Mines of Kalgoorlie (a Normandy/Poseidon company).This traditional underground mining centre has been worked since 1893, yielding 40.5 million ounces of gold ore with an average head grade of TEN grams per tonne. Historically the heart of the operation has been the famous Golden We located on the Eastern perimeter of the city, in the area known as Fimiston. The other significant operations that form KCGM are the Mt Percy Open Pit and the Mt Charlotte Underground Operation.

Jan 1, 1992

By Katom M

Each of the two 32 feet diameter Semi Autogeneous Grinding (SAG) mills at Ok Tedi's copper and gold concentrator was treating at best 1500 tph at about 65 per cent mill availability in 1988. The process was effectively unmeasured and used manu

Jan 1, 1997

Reconciliation of the ore reserve has been an integral part of mine planning since Bougainville Copper Ltd. commenced mining operations at Panguna in 1972. Confidence in the ore reserve is considered essential, both for long term planning of the deposit, and for fair and accurate reporting of the mining resource to shareholders. Recoverable, proven reserves are published annually. Although the ore reserve quoted is based only on diamond drill hole (DDH) information on a 122 metre by 122 metre grid, predictions are regularly reviewed against production. Concentrator results are taken to be the best estimate of grade and tonnage. Surveyed mined perimeters and average blasthole grades are reconciled at the end of each month against the concentrator figures. Predictions of the in-pit reserve are made using an orebody model. DDH and blasthole (BH) sample grades are used to make predictions for both long and short term planning. This paper describes how reconciliations are used to validate ore reserves at Panguna. Development of the orebody model is described, and some of the difficulties encountered in doing reconciliations are addressed.

Jan 1, 1987

By Dionne S, Goodwin F. E

Zinc-aluminium alloy cast matrix composites have been made by squeeze casting, pressure infiltration, spraying forming and stir casting. The overview describes composites made . with these processes. Improvements in properties compared to the conventional alloys are most significant at elevated temperatures. Since stir casting is the most economical viable route of producing composites, progress made in this area is particularly emphasised.

Jan 1, 1993

The Mammoth Copper Deposit consists of three distinct orebodies adjacent to the Mammoth Fault. This fault is arcuate, changing from a normal tension fault to a shear strike fault just to the north of the mine. Movement on the fault was probably contemporaneous with deposit- ion of the adjacent sediments. In the upper levels the No. 1 orebody occurs within a brecciated zone in the footwall of the fault, but at depth the No. 2 and 3 orebodies are stratabound by two brecciated lithologic horiz- ons. The host rocks are impure sandstones, arkoces and quartzites, which in the mine area are near the top of the Lower Proterozoic Myally Beds. Overlying these beds is a conglom- erate siltstone sequence which has been assumed to be the base of the Gunpowder Creek Formation. North and south of the mine the conglomerate rests on an erosional unconformity representing a major time break, but in the mine the uncon- formity and conditions of deposition of the conglomerate are obscure. Some mineralization is contained within the conglomerates. The sulphides present are chalcocite, bornite, chalcopyrite and pyrite. Chalcocite is dominant in the upper levels but could be en- riched by supergene processes. At depth, bornite becomes the dominant copper sulphide with lesser amounts of chalcopyrite, pyrite and primary chalcocite. Throughout the orebody minor digenite and covellite occur and arsenic is a minor constituent bound up with the pyrite. The bulk of the sulphides occur in stringers, fractures and breccia interstices but finer grained primary bedded sulphides can be observed. The genesis is probably a complex process in- volving active tectonic movements extending from deposition to post lithification giving numerous phases of brecciation and redistribut- Ion.

Jan 1, 1974

By Grieveson P, Rajakumar V

The reduction of an ilmenite concentrate with coal at 1000, 1050 and 1100¦C was investigated using thermogravimetry and X-ray diffraction, optical microscopy and electron probe microanalysis of the product. The effects of temperature, coal particle size, addition of ferric chloride and preheating of the concentrate in argon on the reduction kinetics and mechanism were determined. The rate of reduction increased significantly with temperature and was enhanced by the addition of the catalyst. The morphology of the iron was primarily determined by the degree of weathering of the particle. Significant coarsening of iron was obtained in the dense particles by the addition of ferric chloride. The sequence of reduction and the enhancement in the rate of reduction by preheating the concentrate in an inert atmosphere are discussed.

Jan 1, 1991

An investigation was made into the mineralogical characteristics of the upper portions of the 650 and 750 copper lodes. The investigation was based on a comprehensive suite of geological specimens representing all types of mineralization encountered during mining until the end of 1954 and the chief aims of the investigation were to determine (a) the minerals present and their textures and associations, (b) the paragenetic sequence of deposition of minerals in the orebodies, (c) significant changes, if any, which could be found in the orebodies with depth, and (d) the nature and mode of occurrence of nickel in the ore. The general structure of the orebodies is outlined and their mineral composition given. 10 textures exhibited by the ore minerals are described and a paragenetic sequence of events in the formation of the copper orebodies is outlined. No decrease in the complexity of the sulphide mineral textures with depth could be seen and no evidence was found to suggest that the tenor of the ore would decrease with depth although some factors which may eventually limit the extent of the orebodies are noted. The mode of occurrence of minor elements in the orebodies is described. Notes on the occurrence of pyrite, aikinite and berthierite in the orebodies is given and the orebodies are considered to be identified with LiIidgren's mesothermal type of sulphide ore deposit in which considerable replacement of older by younger generations of sulphide minerals occurred.INTRODUCTIONA mineragraphic study was made by Stillwell and Edwards (1945) of a suite of specimens submitted by Mount Isa Mines Limited from the Mount Isa Black Star copper orebodies with a view to determining 1. the nature, extent and association of arsenic, antimonyand bismuth minerals, 2. the mode of occurrence of silver and 3. whether galena and sphalerite occurred in minute forms and below the sizes readily observed in hand specimens.

Jan 1, 1961

In recent years there have been a number of excellent towns built for mining communities in remote parts of Australia. Planning has been thorough, and very large capital expenditures have been made by companies to provide high standards of accommodation, services and amenities. But so often the phrase 'company town' comes to be applied, expressing the frustrations of the residents, working for a single employer who dominates their lives, and of the company, which would prefer not to have to build and operate a town. The much-vaunted early success of some iron ore, bauxite and coal projects has led to a belief that the success of all mining projects is assured. Those holding this belief ignore the vagaries of mineral deposits and of markets, and the need to amortise large high-risk capital expenditures, much of which is spent on social and industrial infrastruc- ture. This expenditure on infrastructure does not have to be

Jan 1, 1975

The South Ghorveh Batholith (SGB) and the Almoughlagh Batholith (AB) intruded the volcanosedimentary sequence of Songhor Series (Triassic-Jurassic), during the Oligo-Miocene orogenic phase. The granitoids of the AB belong chiefly to the quartz-syenite and syenogranite clans while those constituting the SGB can be generally characterised as quartz monzonite varying towards quartz monzodiorite, and diorite. Granitoids constituting both the batholiths are low in free quartz, and possess characteristics of the æmagnetite seriesÆ, mostly of I-type, metaluminous to marginally peraluminous and calk-alkaline type. Adjacent to them are located the magnetite skarn deposits of Baba Ali and Gelali. In the light of petrography, geochemistry, mineralogy and field geology investigations they could be classified as Fe-skarn and mainly bear characteristics of calcic skarn deposits.

Jan 1, 2005

The preferred alternatives in heap design and their motivation are identified as- -normal heap leaching, to be generally applied wherever possible, - flooded vat leaching, to be appliedwhere wetted ore lacks adequate cohesion or if limited space necessitates it,- thin layer leaching, to be applied where deleterious vat chemistry necessitates it.A number of the following features would probably be incorporated in the optimization of normal local heap leach operations- pre-cyanidation - pre-agglomeration - retaining walls- staged (counter-current) heap treatment- control of calcium levels- reduced pH and trickler irrigation

Jan 1, 1984

The Olympic Dam smelter utilises Outokumpu Oy, flash smelting technology to produce blister copper direct from high grade copper concentrate.This paper describes the unit processes involved, including filtering/drying, materials handling, smelting, gas/dust handling, waste heat recovery, sulphur fixing, anode refining and casting.

Jan 1, 1993

The Argyle Diamond Mine came on stream late in 1985 as the world's largest diamond producer in terms of carat output. The design of the process plant, including the heavy medium separation (HMS) facility which provides the initial stages for separation of diamonds from gangue, evolved over a lengthy period of feasibility study and site investigation into the final form described in this paper. The commissioning was carefully planned and co-ordinated, and culminated successfully with handover of the plant on schedule and within budget. Problems encountered during .within were minimal and since then the plant has achieved greater than design throughput during its first year of operation. Darvr_ontmn

Jan 1, 1987

By Tarrant GC

Cement and resin encapsulated tendons are widely used in the stabilisation of mine roadways. One of the main factors in controlling the efficiency of the reinforcement is the ability of the tendon to generate load in response to rock deformation. The analysis of field data from instrumented reinforcing tendons complimented with extensive laboratory investigations have more accurately defined the mechanisms by which load generation occurs. The role of reinforcing tendon profiles, hole geometry and encapsulation medium properties in controlling the reinforcement stiffness and capacity are discussed. The results of the investigation have implications in both the design of rock reinforcing systems and the optimisation of encapsulation mediums and tendons.

Jan 1, 1992

The quality of the rock mass in which an excavation is being driven has a strong influence on the level of dynamic forces to which the excavation can be subjected and sustain damage. Though each specific rock mass occurrence is unique yet there are common rock mass features which influence the outcome of controlled blasting in a similar way. A field study was conducted which involved assessment of blast damage at several operating mines and the blasting of small-scale models. The effects of block size and strength, joint parameters, ground water, weathering of rocks and rock mass rating on the results of controlled blasting have been investigated and discussed in this study.

Jan 1, 2003

Longhole stope overbreak has always been a source of unwanted cost within the underground mining industry, and efforts to control it using various rock reinforcement systems have long been a rock engineering challenge. At the Pasminco Mining Broken Hill Operations trials have been carried out using an innovative cable bolt reinforcement system known as Rib-Roc. The system, based loosely on the Swedish Rib-in-Roc concept, utilises zones or ribs of heavily reinforced rock in the troublesome hangingwall and back areas of longhole stoping. The trials were carried out under a strict qualitative and quantitative scientific stope measurement program utilising rock mechanics instrumentation. Not only did the trial demonstrate the success of the system but data obtained was useful in implementing the system virtually as standard practice throughout the operation.

Jan 1, 1995

By M Bannear, J-F Wilhelmy, R Jones

Mineralogical study of the interactions between fluxes and iron-oxides helps to understand how magnetite oxidises to haematite during pellet firing. Samples of OneSteel magnetite pellets tested at COREM pilot plant were collected after three firing steps and were studied mineralogically. Preheated pellets revealed no particular microstructures related to the composition of fluxes but were more affected by their bed position. After kiln firing, the impacts of lime and magnesia became more apparent. Magnetite oxidation is complete in the cooling stage. The position and the microstructure of the residual magnetite can bring useful information that could æcompleteÆ the view of the firing cycle.

Jan 1, 2007

The areas of impact when employing high productivity long wall systems are reviewed and the financial implications of the most significant areas highlighted. A distinction has been made between availability and utilization. The need for more efficient delay recording, together with increasing control and utilization of the systems has been identified and the measurability of the latter discussed. The increased use of electronic delay reporting direct from the operating unit as the basis for operational control and a pre-emptive maintenance philosophy is seen as an important area of achieving higher performances from existing long wall production systems and Configurations.

Jan 1, 1988

The uptake of nickel into the lattice of pyrrhotite,Fel_oS has been studied experimentally in the temperaturerange 200 DC to 760 DC. Nickel from both aqueous solutionsand salt melts diffuses rapidly into the sulphide latticewith ,an accompanying rel~ase of iron into the solution ormelt. The rate of uptake of nickel and its diffusion intothe sulphide lattice have been followed ,by opticalmicroscopy and by analysis with an electron probe microanalyser.Some geological consequences of this phenomenonaffecting the distribution of nickel in rocks associatedwith nickel-iron sulphide ores are discussed.

Jan 1, 1980

By Murphy MW, Klaric SD

The history, operation and design of the Secor continuous rod production process is described. The effective operation of the plant is influenced by accurate monitoring and control of molten metal properties, mould release application, coolant application and composition and correct setting of all operating parameters. The continuity of operations, which is an essential feature of this type of plant, is also greatly influenced by the service life of wear parts in the operation. This paper deals with three principal wear parts which come into direct contact with copper during operation, these are:

Jan 1, 1985