Search Documents

The purpose of this paper is to describe briefly the clean-up procedure adopted at the treatment plant of Paringa Mining & Exploration Co. Ltd. at Kalgoorlie, Western Australia.A clean-up is carried out at the end of each four-weekly period, and all figures subsequently quoted are taken from a summary of the results of the eight periods ending 8th April, 1941.STRAKING AND AMALGAMATIONOf the total gold won 22· 77 per cent. is recovered by straking and amalgamation.The discharges of both the primary and secondary ball mills are pumped over a common set of five ten feet long by three feet wide straking tables, set at an angle of 10 degrees, before passing to the 14 ft. diameter by 30 ft. by 8 ft. Dorr bowl classifier.This classifier is in closed circuit with both of the ball mills, hence the whole of the circulating load of the fine grinding circuit, which approximates to 800 per cent., is required to pass over the straking tables. For convenience in handling, corduroy cloths are used in lengths of 5 feet, and are picked up and replaced by clean cloths at four-hourly intervals. The avaHable straking area provided is, therefore, 900 square feet, or approximately 3·30 square feet per original ton per 24 hours. The density of the pulp passing over the tables is about 54 per cent. solids, the area provided per ton of pulp per 24 hours being approximately o· 2() square feet. Washing of the corduroy cloths is carried out on the day shift only, about 800 lb. of strake concentrate being obtained daily.This concentrate is sluiced from the washing trough on the elevated straking floor to the 4 ft. by 2 ft. diameter amalgamating barrel located in the gold room below.The barrel is of standard design and is rotated at 25 r.p.m. It is charged each day at 4 p.m., and grinding of the strake concentrate at approximately 70 per cent. solids is continued until 8 a.m. the following day. The barrel is then stopped, and the contents generously diluted with water, and after a few minutes rotation some of the slime is carefully poured off through the small discharge hole. This dilution and decantation is repeated until a good deal of the valueless slime has been removed.A further quantity of strake concentrate is then charged to the barrel, which is allowed a further 16 hours grinding period. After again diluting and decanting, approximately 25 lb. of mercury and 15 lb. of lime are added to the charge, which is then given an amalgamation period of 2 hours before cleaning up.By the process of grinding, diluting and removal of slime by decanting...

Jan 1, 1941

The C.S.I.R.O. acid alumina process employs the essential steps of digestion, hydrolysis and calcination to produce pure alumina from ores too high in silica or too low in grade for the Bayer process. The two latter stages have been described in some detail previously but the digestion stage requires separate discussion since ores vary widely in composition and reactivity. Kaolinitic clays require roasting to 800°C to render the alumina soluble in the 11 per cent sulphuric acid used in the process while some ferruginous laterites require roasting to reduce the reactivity of iron minerals.The iron content of pregnant solutions is kept at a low figure by digesting at temperatures where the solubilities of ferric oxide or basic ferric sulphates are small. A two-stage, counter-current digestion is necessary to extract a high percentage of alumina from the ores and to produce a basic pregnant liquor with an SO3 : AI 203 ratio of 1'\1 suitable for high temperature hydrolysis. The second stage of digestion, called the modification stage, treats slightly acid liquors with excess of ore in the temperature range 1200-1400C.The first stage operates at 170°-1900C to extract further alumina from modification residues, using recycled acid obtained from later steps of the process. Both temperature ranges are critical for economic operation and for proper control of the iron content of solutions. In batch experiments, 30 min is regarded as a suitable retention time for digestion and modification; ores which require much longer than this are less suitable for the process. Impurities such as silica, and titanium and vanadium oxides are discarded in the residue along with iron oxide, and do not contaminate the final product. Bivalent metallic sulphates such as MgSO4, can build up in the circuit to a very considerable degree without affecting product purity.Comparison with other processes shows that the C.S.I.R.O. process is superior for control of contamination by iron, which is the major problem in acid processes. The pure intermediate product (3Al203.4S03.9H20) is also more convenient for calcination to alumina than the hydrated aluminium sulphate usually recovered in other processes. Detailed cost comparisons must await pilot-plant evaluation of the C.S.LR.O process.

Jan 1, 1964

By J D. St George

Flyrock is the unexpected and undesirable projection of rock fragments during detonation of a blast and managing this risk is becoming an increasing challenge as urban development encroach toward mineral extraction sites. The basic factors associated with flyrock are discussed in relation to geology, blast design and management. Published data of historical flyrock events are investigated and compared with local information on incidents. Good agreement was found between the data sets. A computer program of flyrock was developed using projectile motion based on launch velocity and angle, rock size, shape and density. This deterministic model was coupled with a probability model to simulate blast events. The impulse time ?t of the explosive pressure was taken as the stochastic variable to replace launch velocity. The variables were calibrated to replicate field data. A simulation was executed to demonstrate the capability of the approach to defining flyrock danger zones. For a simplistic situation it was identified that an appropriate distance to be cordoned off for the blast danger zone is a radius of 120 m in front of the blast and 65 m behind.

Jan 1, 2001

By J L. Carpenter, S M. Iveson, K P. Galvin

Wet beneficiation of iron ore fines less than 1 mm typically involves a desliming stage ahead of the fine gravity separation such as spirals. The desliming is achieved using a bank of cyclones. The reject ultra-fines emerge in the overflow stream at relatively low pulp density, contain high proportions of low-value slimes, but also well-liberated iron ore ultra-fines below 0.045 mm in size; however, recovering the valuable iron ore ultra-fines from this overflow stream presents a significant challenge due to the need to remove such a large amount of water and slimes.The REFLUX™ Graviton consists of distinct 3D-printed modular units, based on REFLUX™ Classifiers, which are rotated at high speed in a large centrifuge. This system has previously been investigated under semi-batch conditions, demonstrating the potential for precision separations with significant capacity. It has been shown that the throughput advantage of the inclined channels and G forces multiply. This is the first paper presented showing the performance of this system under continuous steady-state conditions. Ultra-fine silica in the size range of 0 to 0.045 mm was fed to the Graviton at different volumetric rates, fluidisation rates and pulp densities ranging from 2 wt per cent to 30 wt per cent, in order to develop a fundamental understanding of the system’s performance. Experiments were then repeated using ultra-fine iron ore.CITATION:Carpenter, J L, Iveson, S M and Galvin, K P, 2017. Separation of ultra-fine particles using the REFLUX™ Graviton, in Proceedings Iron Ore 2017, pp 141–148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

The relationship between comminution testwork results and the milling circuit that is subsequently selected is not a direct one and frequently involves recourse to databases of past test results. This in itself reflects the lack of a systematic engineering approach in the design process. This paper reviews comminution tests for SAG mill design in an attempt to identify where the essential information comes from that will be used in mill selection. The conclusion is that results from traditional test methods, including obscure and little used procedures like the Mokken test, are more valuable from an engineering perspective than parameters for breakage rate based modelling. Suggestions are made on ways in which existing test procedures can be enhanced in order to generate parameters that can be directly related to characteristics of the milling circuit being designed.

Jan 1, 2002

By McKenzie A. M

The Corridor ore body is so named because it occurs in an east-west zone or corridor of schist bounded on the north by the siliceous conglomerates of Mount Lyell, and on the south by similar conglomerates of the Tharsis ridge (Fig. 1). It was discovered after the geophysical prospecting methods described below had defined a target zone for diamond drilling.Since the proving of copper mineralisation by drilling, the corridor orebody has served the vital function of a convenient known target body for the orientation of more recently developed geophysical methods. Traversing of the orebody by these new methods has provided experience for the evaluation of anomalies elsewhere.Some of the methods applied had not been used in Australia before, and were introduced to the west coast of Tasmania through the undertaking there of modern regional exploration programmes. The authors feel that the information gained could be of assistance to others engaged in geophysical prospecting.HISTORY OF DISCOVERYProspecting in the Mount Lyell district has been more or less continuous since 1881. The first geological report was published by Thureau (1886).In 1934, Blazey and Douglas (1934-38) commenced geophysical surveys at Mt. Lyell using the equipotential method.They obtained anomalous indications in several discrete zones and actually detected the south-east half of the corridor orebody but their work never became the basis for...

Jan 1, 1961

By M S. Powell

In this paper it is argued that we are entering a new mining era, based on considerably more challenging orebodies as we rapidly expand minerals production by exploiting previously uneconomic deposits. Rapidly increasing production costs cannot be sustained by continually increasing commodity prices, as illustrated by the recent downturn in the industry.Driven by reduction in grade, requiring the processing of 50 to 100 per cent more ore to recover the same amount of metal, often accompanied by finer grain structure - necessitating a finer product size and more challenging recovery - the productivity of the mining industry is dropping in real terms. The author suggests that tweaking current technologies and relying on economies of scale will not turn the industry around, but rather a switch to considerably more efficient processing is required.It is imperative to utilise the properties of the orebody, especially in terms of variability, in revolutionising our processing techniques. Our new mantra may be æselective mass mining with flexible processingÆ. This paper explores how this may be implemented using current technology and equipment in order to change the cost profile of the new mining industry. Orebody knowledge, based on the underlying process drivers, rather than proxies, is required. These properties and their variability will need to be propagated into the orebody through utilising the geological data rather than smoothing block averages, which destroys information on variability.Novel flexible circuit designs are presented that can respond to a wide variability in ore properties and throughput requirements in order to slash processing costs and energy utilisation, while enhancing overall recovery. The success of these circuits will be based on an ability to predict at both design stage and in everyday processing the variable ore properties, which is dependent upon reliable orebody knowledge that caries variability and underlying processing properties.CITATION:Powell, M S, 2013. Utilising orebody knowledge to improve comminution circuit design and energy utilisation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 27-36 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Waugh D. M

investigations have been undertaken into the flow characteristics of mineral slurries from a number of Australian metallurgical plants including Mount Isa Mines Ltd., North Broken Hill Ltd., and Broken Hill South Ltd. Experimental equipment installed for this work included facilities for continuous recording of flow rate and pressure drop and detection of sedimentation.Although the method has subsequently been described in published literature, it is believed that the investigations included the original application of a method for correlation of the flow rate and pressure drop data. This method depends on solving by graphical methods the values of the constants k, and c in the relationship EQUATION 1 where D is pipe diameter; ?P, pressure drop; L, length; and V, mean linear velocity. Discussion of this correlation also reveals why sedimentation velocity does not necessarily vary greatly with pipe diameter.INTRODUCTIONIn order to design pumps and pipeline installations for a Newtonian fluid, measurements of the fluid's density and viscosity in any of a number of instruments are sufficient. Substitution of these values in well known equations to calculate Reynolds numbers and subsequent correlation to determine friction factors are all that is required for engineering specification.As a result of work during the last decade, particularly that of Metzner and Reed (1955) and Dodge and Metzner (1959), it is now possible to design for homogeneous non-Newtonian fluids using relatively simple instrumental measurements.These methods can sometimes be applied to thick slurries which behave as if homogeneous. However, for the...

Jan 1, 1965

By S Smit, P J. J Strobo

ZINIFEX Century Mine is a zinc, lead and silver concentrate producer. Flotation is the primary method of minerals separation in this circuit. The flotation circuit is quite large with 79 flotation cells. The levels in each of these interconnected cells are controlled at more than 45 level control stations. Due to the multivariable interaction throughout the circuit, good level control was found to be difficult to achieve by just using normal Proportional-Integral-Derivative (PID) control. As a first step in advanced process control, the FloatStar Level Stabiliser, a multivariable controller developed specifically for flotation circuits, has been commissioned at Century mine to solve the level control problems. The first section of this paper therefore discusses and shows the results and improvements obtained by using the FloatStar level stabiliser. The results and benefits of the FloatStar Flow Optimiser are discussed in the second section of this paper.

Jan 1, 2004

By L A. Maslov

We have considered the following characteristics of the crust and upper mantle of the Pacific Belt: seismic wave velocity anomalies, mechanical stress and shear deformation rate fields, heat flow and the pattern of metallogenic provinces of the Belt. It has been noted that there exist certain .regularities in distribution of the above mentioned geophysical characteristics and metallogenic zones within the Belt, displayed by prevalence of the lithophile elements in the Asia-Australian part of the Belt, and of the chalcophile ones within the American part.

Jan 1, 1995

Population growth, social inequality, pollution, global warming, poverty, overexploitation of natural resources and biodiversity loss, are a few examples of the many challenges facing the world today. Sustainable development is about meeting these challenges and improving the standard of living for the benefit of the maximum number of people. These issues concern governments, communities, environmental and social action groups and individuals all over the world. Business too, has a fundamental role to play in delivering sustainable development. In particular, sustainable development is becoming increasingly recognised as a critical issue for the oil and gas industry to address and act upon. BP is committed to positively respond to the challenges posed by the objective of sustainable development.

Jan 1, 2002

Particles of a complex nickel sulphide concentrate (containing pyrite, pyrrhotite, pentIandite, and violarite as the major mineralogical constituents) were entrained in a stream of hot gas the temperature of which was varied from 500 to -1000°C. Chemical analysis of the particulates collected from the furnace was used to detect the rapid change in sulphur content which accompanied the ignition temperature jump. X-ray diffraction analysis was used to characterize the oxidized material.These techniques showed that ignition was dependent on the mineralogical composition and occurred over the temperature range 500-900°C. Pyrite ignited first in the range 500-600°C; pyrrhotite was the least reactivemineral and required temperatures in excess of 800°C for ignition. The nickel minerals <pentIandite and violarite decomposed before ignition and ignited at temperatures intermediate to those required for the pyrite and pyrrhotite. The ignition temperature for the pyrite was found to be independent of particle size and concentration of oxygen in the atmosphere.Ignition temperatures determined by the simulated flash smelting method were compared with the results of differential thermal analysis (DTA) measurements performed on the same concentrate. Temperaturesdetermined in the DTA test as corresponding to the start of exothermic activity were shown to be at least 100°C below those determined by the simulation test.

Jan 1, 1978

By I Sherrell, R Jain, P Jansson

With the depleting iron reserves and difficult market conditions, precision in separation efficiency is of utmost importance. Classical local control options are predominant in the industry, but their inability to adjust to resolve application problems of interest has furthered the need of developing and implementing continuous control methodologies.This paper highlights the recent development in control of Outotec SLon® vertically pulsating high gradient magnetic separator (VPHGMS) including programmable logic controllers (PLC) coupled with distributed control system (DCS), on-site human–machine interface (HMI) control panel, advanced process control, continuous online sampling using Courier® 8 and additional modernisation packages including level control and cooling monitoring. These modern control options result in improved efficiencies, promote safer operation and at the same time reduce operational manpower needs.CITATION:Jain, R, Sherrell, I and Jansson, P, 2017. Automation for efficient separation with the Outotec SLon® vertically pulsating high gradient magnetic separator, in Proceedings Iron Ore 2017, pp 211–214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Research and Tests on Improving the Technology of Enrichment of the Copper-Molybdenum Ore

Sep 13, 2010

A research project was commissioned by the Australian Coal Association Research Program (ACARP) to improve the understanding of tailgate strata mechanics and to provide a more rigorous engineering basis for tailgate support design. A deformation mechanism termed æskew roofÆ was defined which relates the regional influence of differential horizontal strata movement (shear) about longwall extraction to gateroads. Confirmation of the mechanism was achieved by field investigations which included measurement of the shear displacement along weak interfaces. Under geological and mining conditions where the skew roof mechanism operated, strata units were found to move progressively further towards the goaf with height into the roof. 3D numerical modelling was used to assess the major geotechnical factors controlling the mechanism and to determine appropriate support strategies within a æskew roofÆ environment including the role of cables versus standing supports. The skew mechanism is considered relevant to; all roadways in the vicinity of longwall extraction including the faceline itself, chain pillar design, and support design.

Jan 1, 2005

In 1976 the Pitjantjatjara Council was established under the Associations Incorporation Act 1985 (SA), for the initial purpose of organising and bringing together three similar Indigenous groups. These members of the Pitjantjatjara Council of Central Australia were demanding land rights and to legally protect their traditional lands. The Land Rights movement was more focused on the South Australian Government that became more receptive to the general notion that Aboriginal freehold land could be attainable.For almost five years, Pitjantjatjara CouncilÆs intense negotiations took place with the Dunstan and Tonkin Governments culminating in the final passage of legislation by 1981. A bi-partisan approach by Government and opposition applauded by all South Australians for its mature and socially responsible actions, in line with the Aboriginal Land Rights (Northern Territory) Act 1976 (Cth). Despite the similarities between South Australian and the Northern Territory Land Rights legislation, there still remains one obvious distinction. In the Northern Territory case, its legislation established æLand CouncilsÆ as statutory authorities that are responsible for the management and use of designated Aboriginal lands. On the other hand, South Australian legislation fails to include any reference to æLand CouncilsÆ as defined in the Northern Territory Act. The intention of establishing such æLand CouncilsÆ in the Northern Territory was, and is to provide legal, anthropological and other expect advisers that respond to the wishes and opinions of Traditional Aboriginal Owners. Negotiations between mining companies and Land Councils, will, after the granting of mining leases, monies are then transferred to those Councils being a percentage of royalty entitlements. While the Pitjantjatjara Land Rights Act 1981 (SA) (Act) does provide royalty arrangements to Anangu Pitjantjatjara (AP), a body corporate pursuant to the Act as a Landholding Body (and not as a æLand CouncilÆ), it does not provide any royalty payments for the legal and anthropological services by the Pitjantjatjara Council for providing essentially similar services as the Northern Territory Land Councils. The limited services by AP do provide complimentary services from other organisations û including the Pitjantjatjara Council. There are approximately 4000 Anangu members who reside on AP Lands and more than 1000 other Anangu members live near AP Lands in Western Australia and the Northern Territory. These people are defined as APÆs æTraditional OwnersÆ by virtue of their affiliation to portions of AP Lands. As a result, the depth and understanding of spiritual beliefs and customs are strongly present as it relates to the whole of the Lands. Most of these members reside at permanent communities that spread unevenly about the northern and south-western parts of AP Lands. In addition, there are numerous æHomelandsÆ where families and extended families have establish homes, with electricity and water supplies on those Traditional Lands (see Appendix 1 and 2 of this paper depicting the map showing AP Lands and also showing stunning photographs taken during late last year). All roads and airstrips are unsealed between communities and Homelands and the essential services to all communities are limited and costly to provide, and require continuous upgrading. Capital expenditure on infrastructure is sorely needed and alarming levels of unemployment is of serious concern. Tjilpi (older) Anangu members have continually discuss the urgency to provide employment and education for the future of their children and grandchildren while balancing the needs of maintaining cultural and spiritual considerations. It is thus a growing realisation by many Traditional Owners that long-term benefits occur as a result of exploration and production of oil or minerals. There are promising results from Primary Industry and Resources of South AustraliaÆs (PIRSA) Aero-magnetic Surveys on the Musgrave and Mann Ranges and soon to be completed surveys of the remaining southern half of AP Lands (see Appendix 3). PIRSA and mining companies û such as Rio Tinto Exploration Pty Ltd and Delta Gold NL û have been more conscious of the necessity for improving the dissemination of information to Traditional Owners and to AP members. With recent findings of large nickel deposits just over the border in Western Australia, there is a strong indication that discoveries may occur on AP Lands as similar geological information is present on the east Musgrave Block. Consequently there are concerted efforts by the legal and anthropological services of the Pitjantjatjara Council to arrange Workshops and Summit meeting to give extra information û particularly information concerning the true effect of large-scale mining operations û to members to properly consider these proposals. Pitjantjatjara Council will play a major role in any decisions effecting Traditional Owners and AP, and will ensure orderly and professional services when dealing with legal, cultural and sensitive matters. This paper addresses the historical and current relationship between Pitjantjatjara Council and AP, with an emphasis on mining operations on AP Lands. It argues that future economic and social development on AP Lands hinge predominantly on the legal recognition of the Pitjantjatjara Council for its ongoing role, responsibilities and protection afforded to AP and its Traditional Owners.

Jan 1, 2002

With the proving of a mineable orebody at Orlando in May 1961, Peko Mines N.L. was faced with the decision of whether to mill the ore on site or to haul it 25 miles to central facilities at Peko. Orlando was a relatively small orebody, so that it was decided to haul, although no reliable assessment of possible ore haulage costs was available.The necessity for a good haul road was recognised from the beginning and a 17 mile, 12 ft wide, single seal bitumen road was constructed, to link the mine to the Stuart Highway and Peko. The initial selection of 20 ton capacity diesel-powered end-tipping ore carts was made, with the best information available at the time.Since then some 130,000 tons of ore have been carted over a period of 3 years, and this paper presents the experiences of this haulage operation and the lessons learned.A second mine has just been brought into operation at Ivanhoe, 19 miles from Peko. For this haul it was decided to use an ore haulage vehicle of the side tipping road train type, which would cart some 70 tons, or more than three times the load of the vehicles initially selected.Only about 5,000 tons had been hauled at the date of this paper, but preliminary figures indicate a cost 01 1· 65d./ton-mile as against 2·47d. for the smaller vehicles.It would appear that the road haulage of ore from small outlying mines to a central plant can be highly economical, if certain basic rules concerning haul roads and vehicle selection are followed. This paper does not try to determine the maximum tonnages and haul distances which would finally make road hauling uneconomical...

Jan 1, 1966

By B Bamford

High speed diamond cutting has extensive applications in civil and mining engineering. A project involving the diamond sawing of black granite is investigating the nature of the diamond cutting process. A sawing machine was devised to adjust the cutting load and measure cutting speed. Cuttings were collected for size distribution analysis. The surface produced by interaction between diamond. grits and the rock was subjected to microscopic investigation. Increasing load prompts the proportional increase in the cutting rate. But the mean size of cuttings shows little change. The photomicrographs of the cutting tracks indicate neither patterns of crack formation nor signs of the ductile behaviour of the rock. A diamond cutting model for hard rock is formulated on these observations. Diamond cutting is a process of surface failure, which advances in four stages. The polycrystalline characteristics of a hard rock and the action of high-speed diamond grits guarantee the creation of crack nuclei which develop into cracks in various directions. This network crisscrossing cracks enable the stripping of this surface layer from the rock.

Jan 1, 1992

WITH the exception of the deposits of the Milburn Cement Co near Dunedin, Wilson's Portland Cement Co., on the Mahurangi River (a short distance north of Auckland), and those of the New Zealand Portland Cement Co., at Limestone Island, the cement. Tesources of New Zealand remain practically undeveloped. The Milburn Company utilizes a mixture of limestone and mud for the manufacture of cement, while Wilson's and the New Zealand Portland Cement companies both have the advantage of a natural cement stock which requires but small additions of highgrade limestone to give the mixture required. The plant and deposits of the New Zealand Portland Cement Co are located in Whangarei Harbour, some six miles from thetownship of Whangarei. The works and dwelling-houses are situated on Limestone Island, which, with an area of 92 acres, and rising to a height of 212 ft., supplies the bulk of the raw material required. In addition to the island, the company possesses a high-grade limestone area of, roughly, four acres, situated on the mainland, 11 miles to the south. A better location for a cement works could not well have been chosen. On the east side of the island there is a deep channel, which never shows less than 18 ft. of water alongside the company's...

Jan 1, 1912

Gold, silver and palladium may be separated from the other base metals and sulphur contained in copper sulphide precipitates derived from the Sherritt-Gordon nickel process using a process involving an oxidation roast, a reduction roast and a Cu(II)/acetonitrile leach. Sulphur is removed as SO, in an oxidation roast and the hot calcine is reduced with carbon, or with carbon plus cuprous chloride. The resulting product contains metallic copper which is readily dissolved with cupric ions in aqueous acetonitrile solution. Copper powder is recovered by thermal disproportionation. The residue contains the bulk of the iron and precious metals and may be treated by a number of methods, including direct cyanidation or melting with suitable fluxes. Melting the residue will produce a copper alloy containing the precious metals and remove the iron as a slag. The alloy can be recycled to the copper leaching stage or sent for toll refining depending on the precious metal content. Impurities from the leaching circuit are controlled by a bleed circuit which in one approach utilizes the SO, from the calciner to produce Chevreul's salt and separates copper from the soluble cobalt and nickel. Alternatively, the bleed may be directed back to the main refinery copper boil stage or oxydrolysis stage.

Jan 1, 1982