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Many metallurgical beneficiation and primary concentrating processes rely upon discrimination of products from gangue based on particulate density of the different minerals and combinations of minerals in an ore. The basic definition of density is simple, but the apparent density that minerals exhibit when in the environment of commercial densimetric separation processes is more complex and is ill-defined. Measurement of the apparent density displayed by minerals in their separation situation is essential if modelling of plant performance is to be meaningful or when comparison of an existing operation with a æperfectÆ separation constitutes a part of an audit or of a plant control function. Seven methods of dividing ore samples into discreet density fractions are examined and criticised in this paper. The shortcomings, difficulties and potential errors arising from the use of each method are evaluated. Most of the techniques described have been used by the author and generally their faults are understood and the resultant first-hand experience has been used to overcome these faults. A simple new computer-assisted technique for developing meaningful densimetric data is described.

Jan 1, 2004

This paper investigates dry drilling as a feasible alternative to meet current requirements for improvements in mining productivity in an increasingly competitive world.A field test program was conducted in the surface facilities of a hard rock mine in Sudbury, Canada, to investigate the potential use of dry drilling in underground bulk mining as a conceivably faster and more economical method than wet drilling. The test work consisted of the monitoring of advance rates and bit life while a series of 165 mm diameter holes, wet and dry, were drilled with compressed air at both mine (0.69 MPa) and high (1.72 MPa) pressure levels. The results indicate that penetration rates can be increased by approximately 24 per cent by drilling dry with high air pressure and by approximately 27 per cent by drilling dry with mine air as compared with wet drilling under the same conditions. Dry drilling also has the effect of increasing bit life by up to 69 per cent. An economic analysis for typical hard rock mines indicated that drilling productivity and cost savings can be increased by approximately 23 per cent when dry drilling is utilised.The testing program indicates that dry drilling has the potential to become a feasible technique with regard to performance, productivity and costs.

Jan 1, 1991

By M J. Kelleher

CREAM is an acronym for coal recovery, evaluation, analysis and management and is a business improvement project at BMAÆs Goonyella Riverside mine that is focussed on maximising coal recovered. In August 2003, Goonyella Riverside was set a challenge to quantify coal loss and dilution and their relationship to cost, revenue and ultimately profit. While the mine was confident in its site forecasts of recovery (and loss), it was clear that the traditional measurement and analysis systems were inadequate to firstly, identify key loss areas and mechanisms and secondly, successfully quantify the benefit of various coal recovery initiatives. The path that BMA Goonyella Riverside has travelled to maximise coal recovered can be divided into four key steps: Mapping the process û This step involved the development of a coal flow process map for Goonyella Riverside that stepped through each component of the process from the coal reserve to the customer and identified key measurement points for the purposes of reconciliation. Understanding coal loss and identifying opportunities û This step involved conducting two detailed Reserve to Customer projects at the mine site to track a block of coal from the reserve to the customer and to gain a greater understanding of the relationship of dilution, coal loss mechanisms, revenue and costs associated with recovering additional coal. Coal data systems development û Two important coal data systems have been developed and implemented at Goonyella Riverside in the past twelve months, namely SnowdenÆs Coal Reconcilor and SeamFix. These systems enable coal losses and dilution to be quantified and reconciled back to the initial coal reserve. Implementation of loss reduction initiatives û This step involved the formation of a business improvement project referred to as æCREAMÆ in August 2004, for the purposes of improving pit coal recovery and maximising business value. To date a series of coal recovery trials have been run in a number of pits at Goonyella Riverside that have yielded significant improvements in business value. The key to the success of this project has been the discipline to follow a defined process map, management commitment through resourcing and shared key performance indicators, a successful acceptance strategy resulting in holistic ownership and the implementation of sustainable reconciliation systems. Coal loss and dilution are now quantifiable and their relationship to cost, revenue and ultimately profit is well understood. This paper discusses the process that Goonyella Riverside has adopted to maximise coal recovered.

Jan 1, 2005

By Waterhouse BJ

Occurrence data of Tastubian,Sterlitamakian, and Aktastinian (all of Sakmarian Stage of Early Permian) brachiopod genera are analysed by Q-mode cluster analysis, principal component analysis, and discriminant analysis based on presence or absence of genera. Five faunal provinces and their corresponding generic associations persisted throughout the Sakmarian Stage. The additional Sasian Province incorporating the Lhasa and Shan-Thai terranes became recognisable in Sterlitarakian and strengthened in òAktastinian, implying a Tastubian-Sterlitamakian rifting event, followed by subsequent northward drift and divergence from Gondwana, and convergence with Laurasia. The nature of Permian 'Tethys' is discussed on the basis of faunal migration and abrupt changes of faunal provinciality in Lhasa and Shan-Thai terranes.

Jan 1, 1990

A brief history of the significant haulage truck feature changes and the factors that influenced those changes during the 60's and 70's provide a basis for forecasting the changes that can be expected in the 1980's. A review of the impact factors and changing requirements that currently exist that will create changes. Define the critical requirements of a successful haulage truck design and discuss the availability of bigger engines and better electric drive componetry to provide deeper pit capability and improve reliability. The Unit Rig Trolley Assist System to provide improved productivity and diesel fuel savings and an economic analysis to evaluate the Trolley System is covered. The Unit Rig Automatic Truck System for a driverless truck is covered in concept and discussed from the point of view of the experience in a test in a New Mexico mine. INTRODUCTION A good basis for trying to forecast what is going to happen in the future is to go back a little bit in history, to see what the influencing elements were in different periods of time as a foundation for the forecast. INFLUENTIAL FACTORS IN THE 1960'S If you look at the truck development that occurred in the 1960's, there were some identifiable factors that give us insight. (See Fig. 1) Several things happened at the beginning of the 1960's. Mechanical drive haulage trucks were introduced that were

Jan 1, 1982

Platinum Group metals have been known in New Zealand since the 1880's but not produced on a large scale. They have been neglected because their value was not appreciated rela- tive to gold and their value was often very low, reflecting demand, and because recovery was difficult compared with recovery of gold. With the rising price of most Platinum Group metals and the perfection of gravity and flota- tion recovery methods, recovery of platinum along with gold from alluvial deposits is more attractive. Platinum Group metals are known in several different environments in New Zealand, ranging from alluvial placer deposits to layered basic to ultrabasic intrusions and quartz veins. None of the known occurrences have been ade- quately prospected and there is a real possibi- lity of future discovery of important deposits. Several New Zealand based and at least two offshore resource companies are currently involved in exploration, prospecting or mining for Platinum Group metals in New Zealand.

Jan 1, 1987

By M Gao

Six new IsaMills were installed for the George Fisher flowsheet in the Lead/Zinc Concentrator of Mount Isa Mines to produce a product P80 as fine as seven microns. The objective was better liberation of galena and sphalerite. The IsaMill commissioning was completed by the end of 1999. The six new IsaMills were running to the metallurgical specifications almost immediately after start-up. This paper reports the performance of the George Fisher IsaMills in the zinc circuits and some of the latest development in the IsaMill designs and maintenance during George Fisher commissioning.

Jan 1, 2000

By Mayer TE

The Granites Goldfield is located 550 km northwest of Alice Springs. Mineralisation was discovered in 1900 and intermittently worked along nine km of strike until the early 1950's, yielding a recorded production of 470 kg of gold. The geological environ- ment, pre-existing exploration drilling results, and an optimistic view on gold, prompted acquisition of the property by North Flinders Mines Limited in 1975. An agreement was signed with the Central Land Council in August 1983 and drilling commenced in the same month. In the past, gold was won from alluvial deposits, rich quartz veins and lower grade, disseminated stratabound mineralisation. The last is contained within a distinctive unit in the Mt. Charles Beds, of the Early Proterozoic Tanami Complex. This informally named "Host Unit" is a metamorphosed, chemical- pelitic sediment. The schist contains variable proportions of amphibole, quartz, garnet, clinopyroxene, carbonate and sulphide, inter- calated with recrystallised chert beds. Free gold occurs in several mineralised horizons within the Host Unit, generally conformably distributed within lithologic bands or at lithologic contacts. The Host Unit occurs within a sequence of metamorphosed pelitic sediments and intermediate volcanics. Although mostly confined to the Host Unit, stratabound gold mineralisation also exists in both Footwall and Hanging Wall Schists, usually within zones displaying certain Host Unit characteristics. The deposits may be loosely categorised as being of banded iron formation (bif) type, although some important differences are noted between them and classical bif type orebodies.

Jan 1, 1984

By P R. Lock

The Silver Swan nickel mine is located at the Black Swan Nickel Project, 53 km north east of Kalgoorlie, Western Australia. The Silver Swan orebody is a massive sulphide nickel deposit dipping 70¦ east with an average in situ grade of 14 per cent. Mining of the massive orebody is by Mechanised Ramp Cut and Fill (MRCF). A mining recovery of 98 per cent and minimising dilution are primary goals in extracting the high-grade ore. Placing a distinguishable marker bed (working platform) on rock fill was identified as a key method to achieving these goals. Gravel from a pit located onsite was considered the most suitable material for the marker beds. Research undertaken to design the marker beds using the gravel revealed conventional methods used in mining would not suffice, but that road stabilisation methods could be a viable alternative. Trials used a road recycler to mix cement and gravel in situ and several test beds were constructed on the surface to determine the final design. The trials attempted to replicate a marker bedÆs life cycle of construction and placement and mucking of ore from the marker bed. Testing the marker bed for strength for use as a working platform was completed using a Clegg Hammer; good correlation to a Clegg Impact Value and the compressive strength of the stabilised gravel was found. This paper describes the use of a road stabilisation machine, tests conducted, monitoring and marker bed design and discusses underground placement of the marker bed and its performance.

Jan 1, 1998

The mining industry worldwide relies upon the identification of resources that can be economically developed and operated. Access to land is paramount through all stages of the exploration, development, operation and rehabilitation stages. Clear rights to use of land for the purposes of mining must be available and protected throughout the life of the project. Stable and enduring criteria for mining of the resource, once identified, are required to attract exploration and development expenditure. The purpose of this paper is to investigate the varying approaches to granting access to land for use for exploration and mining development, including the processes by which a project is approved by community and government and the time scale for such approval. The paper concentrates on the legal issues arising throughout this process. The law is stated as at September 1997.

Jan 1, 1997

Seven papers included in Session 8 of the Third International Mine Water Congress under the heading "Achievements in Mine Water Management & Research" have been reviewed. Only one paper, a case study by Masters on biological treatment of inorganically polluted effluent, has any connection with research in the sense of seeking new, generally applicable knowledge which would advance the frontiers of mine water management. The remainder deal with various aspects of the management of mine water ranging from investigation of the geology of a specific aquifer system through operating dewatering systems to the management of specific effluent disposal problems.

Jan 1, 1988

By Bassett N

The Eneabba deposit, located 280 km north of Perth, Western Australia, and 30 km inland (Fig. 1) is one of the most recently developed deposits of mineral sands in the world. The area has been in production since 1974, while the Associated Minerals Consolidated Limited (AMA) operation commenced production in 1976. Total ore reserves of close to 400 million tonnes contain about 40 million tonnes of heavy minerals (proved and probable).

Jan 1, 1979

By Xueqiu H

Since the hypothesis of coal and methane outburst mechanisms based on elastic mechanics gives no consideration to time, it cannot give satisfactory explanation of the outburst occurrence and its development. A creep mathematical model of coal containing gas has been set up through creep tests and analysis under a condition of triaxial compression. Such a model can explain the phenomenon of coal and methane outbursts successfully. The tests proved that there is no essential difference between the rheological properties of prone outburst coal and non-prone outburst coal. Outburst can take place in any kind of coal if the rheological conditions of coal containing gas are met. The creep mathematical model provides a basis for establishing a comprehensive index of coal and methane outburst potential.

Jan 1, 1992

Incompetent ore and country rock have caused stability problems in longhole open stopes. Fully grouted pre-placed cablebolts have reduced these by preventing ground relax- ation and joint dilation to maintain a self supporting rock structure. Larger atope spans can now be opened with the same or smaller pillar. Mining methods are expected to become less dependent on original ground conditions. Effect of spacing, orientation and stress distribution along the cablebolt is not fully understood at this stage and requires more Observation.

Jan 1, 1977

By Boyd G

This paper describes the planning, analysis, design and operational experience of highwall mining based on auger drilling techniques applied to thick coal seams exposed in an opencut highwall. Being the first time such technology has been used in Australia, a large commitment to technical design and logistics planning was given by Callide Coalfields Pty Ltd. This commitment included technical and operations management and supervision, mine services, and the retention of consultants to undertake geotechnical analysis, instrument preparation and instrument installation.

Jan 1, 1991

By Crosby N. R

The design of mine openings and the assessment of their reserve are processes ihicl, require the routine manipulation of considerable amounts of data. A number of computer programs have been assembled to operate in a mini computer in order to provide some mechanical assistance for these processes. The system responds to plain language commands. which allows mining engineers to compute the reserves for a number of possible mining outlines, on an interactive basis. Methods of numerical analysis were used in preference to statistical or qeostatistical techniques.

Jan 1, 1977

By Wright S, Jorgensen F. R A

The reaction between lead sulphate and a number of base metal sulphides (galena, sphal- erite, chalcopyrite and synthetic pyrrhotite was studied as a means of desulphurizing lead sulphate containing fumes and residues to levels acceptable as ISF feed. The reactants were mixed with 50% zinc oxide to act as a "basket" to contain the molten products of the reaction and pressed into small briquettes 20 mm in diam. Factors such as temperature, time and the composition of the atmosphere were investigated. Using the PbS/PbS04 system as an example it was shown that the reaction became rapid above 800¦C and that both sulphur dioxide and oxygen in the atmosphere were detrimental to achieving low sulphur in the product. In an inert atmosphere all the sulphides when roasted for 1 h at 1000¦C gave results corresponding to the elimination of more than 95% of the sulphur in the reactants. Leach plant residues were considered for use as the "basket" material. It was shown that the residual sulphide and sulphate components of the residues underwent similar reactions to those experienced by the pure systems.

Jan 1, 1987

By J Wu

Swirl Flow Technology (SFT), a novel approach for agitation in large industrial slurry tanks, was jointly developed and patented by CSIRO and Queensland Alumina Ltd (QAL). Currently, SFT is used in 16 alumina precipitation tanks at QAL, with the first installation in January 1997. This paper provides insight to the underlying fluid dynamics, which were investigated through pilot-scale experiments. A key finding was that SFT produces tank wall velocities approximately four times that of conventional draft tube agitator systems for the same power input, whilst for solids suspension, much less power is needed. SFT is energy efficient and practical in scaling suppression as demonstrated by the full-scale experience at QAL.

Aug 8, 2011

In the past two decades the global metalliferous mineral industry has trended away from pyrometallurgical (pyromet) and towards hydrometallurgical (hydromet) technologies including biometallurgical (biomet) processes. Pyromet, biomet and hydromet technologies have all developed considerably over this period. New projects have been biased or directed by legislation towards supposedly cleaner and greener hydromet and biomet technologies. The environmental cost and energy cost of pyromet production processes for copper and cobalt are compared with comparable hydromet processes using Life Cycle Assessment (LCA). The æreal costÆ of the global warming obsession and negative public perception of pyrometallurgy include greater carbon dioxide emissions and energy consumption per unit, associated with current hydromet technologies. Specific examples for copper and cobalt produced via the different routes are provided. The poor science involved with the global warming hypothesis is discussed. The use of LCA with sensitivity analysis as a decision making tool for mineral processing projects and technology developers is discussed.

Jan 1, 2004

Establishing the link between the solid, cold rock of dikes, sills, plutons, and lavas and hot, active magma chambers is the quest of igneous petrology. Differentiation of Earth, the diversity of the igneous rocks, and the spectacle of volcanism are ample evidence that magmatic processes are fundamental to our understanding of planet formation and evolution. Single gabbroic plutons, on the other hand, often show intricate and abundant evidence of the effects of crystal growth and sorting. It has not proven simple, however, to establish the basic principles of magmatic behavior leading to this crucial evidence. Because of their abundance, exposure, simple geometry, large range in size, and often straight-forward petrology, sills are excellent examples of the magma chambers. Physical and chemical processes operating in sills can be recognized that also routinely operate in many other bodies. Understanding the dynamics of sill solidification is essential to understanding the genetic links between lavas and plutons.

Jan 1, 1990