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A number of mines in Australia have experienced premature detonations caused by bulk explosives reacting with the rock type being blasted. Premature detonations are extremely high risk events as they are unplanned, occurring at any place, at any time, potentially resulting in high loss (personnel and equipment). Many Australian mines have also experienced spontaneous combustion where spilt explosive reacts vigorously with the rock type. Premature detonation in these cases does not occur due to the lack of confinement and the volume of explosive present, but these reactions could impinge on the surface initiation system and provide an early warning of future premature detonations. The explosive ground reactivity phenomena is not restricted to Australia with similar incidents being reported in North and South America, South Africa, China and South East Asia. All reported incidents have two common denominators, being the presence of sulphide rock types and nitrate based explosives. Both premature detonation and spontaneous combustion result from the same series of reactions of partially weathered sulphides that ultimately result in the violent decomposition of the ammonium nitrate based explosive. A number of relatively easily observable indicators can be used to assess a particular minesiteÆs potential for explosive ground reactivity. The presence of two or more of these indicators means that minesite personnel should contact their explosives manufacturer for assistance in determining if a problem exists and if so then developing strategies to overcome the situation. The paper describes the indicators as well as discussing, via a case study, the holistic approach required to efficiently develop a relevant æSafe and Efficient Blasting ProcedureÆ to deal with explosive ground reactivity problems.

Jan 1, 1999

THE writer of this paper well realizes that the majority of engineering and metallurgieal works have from time to time evolved mechanical devices which are of great value as regards application in an operating plant.Many of these deviees would not be apparent to an individual making a brief inspection of works such as these, and it is for this reason that the writer proposes to outline a few of the devices which have been evolved by the engineering department of the Broken Hill Associated Smelters Pty. Ltd.NOVEL METHOD OF MACHINING A SPHERICAL JOINTFig. 1 represents one half of a casing for a ball-joint coupling. In the ordinary methods of boring an external spherical casing, that is with a radius bar attached to the tool rest of a lathe, there is always an error in the bore. It has two flat sides, and this error is inherent in the ordinary orthodox method and cannot be corrected. The engineers of the Broken Hill Associated Smelters Pty. Ltd. undertook a job that had to be extremely accurate, and the tool shown in Fig. 2 was evolved. The tool is not exactly fool proof, but in the hands of an average mechanic an absolutely perfect FIG. 1. sphere can be bored. The casing has to be held in the lathe in such a manner that one half can be removed without affecting the setting of the work. The business end of the tool is then placed inside the...

Jan 1, 1922

By Y Zhang

Being analysed systematically, the factors influencing the production of fully-mechanised coal face have been divided into geological, mining technical, and management groups. Artificial neural network-expert systems (ANN-ES) are established to decide the influencing factorsÆ membership grade; genetic algorithm-artificial neural network (GA-ANN) are used to decide the weights; fuzzy comprehensive evaluation method is used to calculate the integration indexes. Finally, the GA-ANN model is established to forecast the production of fullymechanised coal face. It is proved that the model is reliable with higher precision. The production of fully-mechanised coal face is influenced by many factors. However, some influencing factors are neglected by the traditional forecasting methods, the results of which are not precise and hardly be used as a guide for mine production and management. The relation between the production of fully-mechanised coal face and its effecting factors is analysed, and the meta-synthetic AI approaches are used to forecast the production of fully-mechanised coal face.

Jan 1, 2003

By Bell MG

At various decision points in the development of a project, a developer, joint venture partner or financial institution may require an independent review of the basic assumptions and technical aspects of the project. This type of review or technical audit is becoming a more common feature of the project development process. This feature has evolved because of the need of investors and lenders to be more confident of the viability of a project by the confirmation of its technical and cost aspects. Technical Audits offset some uncertainties introduced by the combination of longer development periods for, projects and the highly dynamic world economic scene. This paper reviews the place, nature and process of the technical audit by examining the circumstances when it might be needed, the typical scope of work or brief, the responsibilities of and relationship between the auditor and the client, and the auditing procedure. Detailed aspects of technical audits are discussed followed by a case study of the Hail Creek Coal Project Audit.

Jan 1, 1983

Having successfully applied computer techniques to open pit mining applications, many software developers are now using their skills to tackle the much harder areas of underground mine design, planning and production.Dramatic improvements in the performance to price ratio of hardware (including high resolution graphics screens), a better understanding of the techniques of surface and solids modelling (and their subsequent display), moves towards standard user interfaces and advanced concepts of representing grade distribution in the ore body have all contributed to the recent increase in underground mining software activity.This paper details the general requirements of a workable underground mining software system, providing a minimum checklist of desirable features and emphasises the importance of ease of use, flexibility and intuitive feel. Some relevant trends in hardware, software and application techniques are highlighted and comments made on areas which require further development or are only available in a small number of packages.Finally, a comment is made on the role of computer models to provide a unifying medium for tying together all aspects of underground design, planning and production.

Jan 1, 1992

The Beaconsfield gold mine processing plant is a complex operation and utilises crushing, grinding, gravity gold concentration, sulfide flotation, bacterial oxidation, cyanidation and zinc cementation to recover gold from the partially refractory ore. This paper discusses the challenges, developments and advancements throughout the processing plant since start up, which have culminated in a 25 per cent increase in the mill throughput over the nameplate design and a concomitant gold recovery increase from 75 to 92 per cent. The improvements have been attained via advancements in mechanical integrity, metallurgical review, process control and operator training, resulting in the current operation producing over 630 000 ounces of gold to date.

Jan 1, 2007

By Hemingway J, Read T. A, Anderson V. G

IN the determination of very small amounts of lead, the usual analytical methods are far from being satisfactory. Small amounts of lead may be present in the reagents empioyed, and it is customary to run a blank experiment to correct the error arising in this way. When the correction is of small magnitude compared with the amount of lead in the sample, this procedure may be adopted; but when very small amounts of lead are being determined it may happen that the lead found in the blank is as much, or even more, than the lead actually present in the sample, and the analysis has to be rejected. Moreover, the blank experiment cannot check errors which are not common to the blank and the analysis itself eg, the apparatus used in the parallel experiments, etc. It seemed to be desirable, tl;l.erefore, to make an investigation of the problem to ascertain, as far as possible, the nature of the errors arising from the introduction or loss of lead during the analysis, and how far these could be eliminated or corrected for; also, to determine the limits of accuracy of the improved method and the minimum amount of lead that could be reliably estimated.In the investigation, reliability and sensitiveness were regarded as essential features. Speed of operation, on the other hand, was considered of less importance. The amounts of lead dealt with being usually less than 1 mg, there is no alternative to the use of a colorimetric method. The latter, depending as it does upon the development of a brown coloration when ammonium sulphide is added to a very dilute -solution of a lead salt, is far from being a characteristic test for lead. Indeed, it is well known that the salts of most of the commonly occurring metals interfere with this test. Hence it is of vital importance that the lead should be isolated in the form of a pure compound possessing quite definite and characteristic properties before the colorimetric estimation is proceeded with...

Jan 1, 1921

By Harris R. W

Any defect activity resulting from an applied stimulus on a structure will generate a stress wave which travels in the medium under the laws of acoustics, thus the name of acoustic emission (AE). AE techniques can therefore provide information on the deformation of both surface and below ground structures. Two operating coal mines were monitored from the surface, and both mining activity and post mining microseismic activity were detected. The nature of the detected AE signals demonstrated that there were a range of deformation mechanisms in operation and that some predictive capabilities were possible with the Technique.

Jan 1, 1992

During the past eight years a vigorous drilling campaign resulted in large increases in the reserves of both copper and silver-lead-zinc ores.As a result the Company initiated an increased production programme.Some major capital works have been completed, others are in progress and more are needed to achieve the proposed daily throughput of 14,400 tons. The increased ore potential justified a copper refinery which has been constructed at Townsville. The increased production rate achieved to date, combined with improved techniques and greater mechanization, is assisting the Company to combat the general inflationary trends caused by increased costs for labour and materials.INTRODUCTION"Today we are armed with better weapons in our fight for lowered costs and greater efficiency, but we must not flag in our efforts to improve." Such was the resolution expressed by Mr. K. B. Gross, then General Manager of the Company, in his review lecture delivered to the First Ordinary Meeting of The Australasian Institute of Mining and Metallurgy at Mount Isa on 18th August, 1952. This present review of the period 1952 to 1960 records our efforts to fulfil this resolution. At the th:ne of Mr. Gross's statement,copper production was commencing in earnest. Although the importance of Mount Isa's copper orebodies was well recognized, the major discoveries which led to Mount Isa's emergence as Australia's premier copper mining and smelting operation were not known. These ore discoveries and their subsequent development are the major factors which warrant a further review of the Company's progress.The increased magnitude of the Company's operations is illustrated on graphs of Tons of Ore Treated (Fig. 1), Metals in Products (Fig. 2), Water Consumption (Fig. 3)...

Jan 1, 1961

By R Willis, D Cooke, G J. Davidson

Mine-groundwater interaction at the Pasminco Rosebery Mine (PRM), western Tasmania, deserves special attention due to the unique climate and mining environment present. High rainfall and low evapotranspiration result in an excess of water, an uncommon problem at Australian sulfide bearing mines. Research is being undertaken to delineate current subsurface fluid flows and predict future fluid flows in order to improve management after mine closure. Acid mine drainage generation is well developed in abandoned mines throughout the area. If acid mine drainage is not controlled after mine closure, significant environmental degradation could occur in the receiving waters of the Pieman River system. The study area encompasses the heavily forested Mount Black, and underlying PRM workings. Groundwater flows beneath Mount Black through a crystalline fractured rock aquifer with faults and underground mine workings observed to act as the major hydraulic conduits. Recharge is controlled by local precipitation, and the ultimate discharge is thought to be the Pieman River system, which forms the topographic low in the area. Slug tests have been used in conjunction with the mineÆs extensive geotechnical database to spatially evaluate variation in hydraulic conductivity. In fractured rock terrain associated with mining, rock quality designation data can be a useful tool in delineating areas of similar hydraulic conductivity when combined with conventional hydrogeological methods. A GIS, mine planning software, an environmental and a geological database are linked to form the input for groundwater modelling.

Jan 1, 2003

I start with some lines from "Pleasures of Hope" by the poet Campbell, published in 1798, which sets the flavour of what I am going to say. They blissful omens bid my spirit see The boundless fields of rapture yet to be; I watch the wheels of Nature's mazy plan, And learn the future by the past of man. I hope to echo the poet's optimistic view of what is yet to come. I am not sure I can find all the omens blissful but we all have some experience of what the wheels of Nature's mazy plan get up to. His advice to learn the future by the past of man seemed sensible to follow, so on the principle that the past of several men would be better than one alone I invited Alan Attwood, Maurice Cahalan, Gavin Moncrieff, Derek Temple, and Peter Wright to help me prepare this address; I am most grateful to them for their contributions. Of the technologies covered in this sequence of keynote addresses, metallurgy is the one which is closest to our consumers. On the age-old principle, which I do not expect to see changed in the 21st Century, that production is about providing the customer with what he wants, when he wants it, where he wants it, and at a price he can afford, I think we should start by trying to see how the market place is likely to develop, and to work back from there to review what technology we need to meet these demands.

Jan 1, 1986

By K Brown, J Webster-Brown

Coal mining activity first began on the West Coast in 1864 and has since led to the exposure of large areas of coal and host rock to chemical weathering. These exposed abandoned workings have led to the formation of acid mine drainage, which flows into selected rivers and streams impacting on the natural environment. A previous study conducted for the West Coast Regional Council identified four catchments receiving mine drainage which had elevated arsenic concentrations. The aim of this research is to expand on this initial study by determining the spatial distribution and attenuation of the arsenic within the sediment and water column in each stream of concern. Cannel Creek is influenced from drainage from the Bellevue coal mine adit and exhibits a low pH of ~3, elevated sulfate concentrations and high arsenic and iron concentrations in the sediments. This pattern is repeated in the Rapid Stream and Soldiers Creek catchments, which are also affected by adit inflows from the Sullivan and Blackball coal mines respectively. Soldiers Creek also has significantly high arsenic in the waters, with an accompanying pH of ~5.5. Snowy River exhibits a similar trait with a pH also of ~5.5, but with very low sulfate concentrations. Arsenic concentrations in the waters are consistently around 30 ppb, with sediment concentrations up to 900 ppm. These sediment values might be partially attributable to the operation of the Snowy battery gold ore production facility, but the consistently high As concentrations in the water column and in the sediment upstream of the battery have an as yet unconfirmed source.

Jan 1, 2002

THE auriferous sulphide ores of the eastern end of Gippsland, and notably of the Cassilis and lVIitta districts, are amongst the most complex and refractory in Victoria-perhaps in Australia. The minerals occurring in these ores are pyrite, arseno-pyrite, zincblende, galena, and (in smaller amounts) some of the copper, sulphides, as chalcopyrite and covellite; and some of the antimonial minerals, notably stibnite and jamiesonite. In the oxidized portions of the lodes, the oxidized lead and iron minerals, and small amounts of the hydrated arseriiate of iron, are found.In the Cassilis mine, near Omeo, copper is present usually in quantities of under 1 %. The magnetic sulphide of iron is of fairly common occurrence. In, the upper levels of the Cassilis mine tin was usually present, the amount going up to 3% in some samples of concentrates. These minerals occur sometimes banded, but usually as an intimate mixture-pyrite and arseno-pyrite predominating. The gangue is usually quartz (blackened by enclosed particles of sulphides). Calcite, magnesium silicate and felspar are also present in varying amounts.

Jan 1, 1911

Mill liners provide the wear-resistant surface within grinding mills, they also impart motion to the mill charge, ie the grinding process, by providing the key between the charge and mill shell, and, at the discharge end, they remove the ground contents of the mill. As semi-autogenous grinding (SAG) mills have grown in size the process aspects of liner design and their impact on mill performance have become particularly important. While feedback from practical experience is critical to good mill liner design, increasingly sophisticated computer-based tools are being developed to assist in mill liner design.

Jan 1, 2007

The truly scientific method in the study of such questions at the present day is the reverse of that which was followed in the early days of geology, when after the observation of a few isolated facts, some great geological mind was led to a general theory, and humbler followers were only too apt to do mild violence to nature in order to make her facts conform to it tt accumulates year after year a multitude of facts of patient observation, supported by studies with the microscope, and in the laboratory, avoiding general theories, and only making such deductions in regard to locftl conditions as are supported by the overwhelming evidence of facts. S. F. Emmons, on the geological distribution of minerals in the United States, at the "world's congress" of mining engineers, Chicago. Fig. l.-This exhibits the general stratigraphical characters of the southern lodes. The" Indicator" veins, the great barren lode masses, a later fissure than all of these (" B "), and the auriferous lodes of last series cleaving the wrinkled terraces and the older lodes also are" Indicator" veins. B is a later formed vein that leaves no " depositions" behind. ooe are fragments of the" most ancient'' lode wreckage. Db are the auriferous lodes and correspond with those lodes, also whose auriferous characters are not result of secondary impregnations.

By Burchell S, McGregor K

The process of design, measurement and review is essential if blasting is to continuously improve to meet the increasing productivity goals of most mining operations. To achieve continual improvements, many operators are turning to contractors to provide the necessary technology. Under this arrangement, the contractor becomes the supplier of a service rather than products and assumes some of the risks associated with blasting by guaranteeing the end result. If contractors are to obtain significant productivity improvements they must continuously improve every aspect of their business.

Jan 1, 1994

By Ghiani M, Satta F, Zucca A, Peretti R

After a brief introduction on the principles of contact electrification and a synthetic illustration of the Turbocharger separator, the successful results obtained with different raw materials are given and discussed, with particular reference to a North African run-of-mine with carbonate gangue, a crude ore from India containing pyrite and a mineral sample from Angola having quartzeous gangue. The pre-eminent effect of target surface temperature in the charging device of the separator is emphasised. On the basis of the results of both batch experiments and long-run tests the prospects of industrial application appear very interesting both from the technical and economic points of view, even when compared with froth flotation.

Jan 1, 1993

IntroductionOre BodiesRio GrandeBlack RockLeadCopperBlack StarLeadCopperStoping Methods and DesignFactors Affecting Ventilation PracticeTemperatures and Climatic ConditionsGeothermic GntdlentLegal RequirementsMine CasesMain Ventilation SystemMajor Fans and ShaftsVentilation CircuitsMan and Supply Shaft; No. 2 Ore Shaft; Urquhart ShaftMan and Supply Shaft; Davidson Shaft; No. 46ShaftLawlor Shaft; Urquhart ShaftControl of VentilationSummary of Upcasts and DowncastsAuxiliary VentilationType of Fans used, Vent Pipe, etcVentilation and Temperature SurveysDust SurveysInstruments Used

Jan 1, 1953

By D Manhire, G Hogan, M Ryan, S Whiteley

Site restoration at the L&M Mining Limited alluvial gold mining project at Waikaka near Gore, Southland is described. In 2000 mining operations started to recover alluvial gold beneath historical dredge tailings over 244 hectares in the flood plain of the Waikaka Stream. The project had an eight to nine year mine life but was prematurely closed in 2002 because of economic considerations. Restoration of the site back to pastoral farming, with shelter-belt and amenity tree, shrub, and wetland plantings is described. Dealings with the landowners and regulating authorities are addressed in the paper.

Jan 1, 2003

Australis Mining N.L. operates a continuous mode carbon-in-pulp (CIP) gold plant, processing sand and slime tailings from previous gold mining operations in the Norseman area. Plant design is that of conventional countercurrent contact between pregnant pulp and activated carbon. Gold desorption is achieved by the Zadra process using near boiling tempera- tures and atmospheric pressure. Process water is drawn from nearby Lake Cowan (saline). The plant operates at, or above, design specification of 400 dry tonnes per day. This paper describes the plant design and operating processes utilised in optimising throughput and gold recovery. TNTDnPTTnmTnM Favourable world gold prices and substantial reserves of sand and slime tailings prompted Australis Mining N.L. to construct a gold extraction plant during 1981. The projected plant throughput was set so as to complete treatment of available tailings over a three year period. Metal- lurgical tests indicated that, with a regrind facility satisfactory gold recovery could be achieved using a countercurrent CIP process. Reflecting the entry of Australis Mining N.L. into its first large scale treatment operation, the plant design emphasised simplicity but effectiveness of Operation.

Jan 1, 1982