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By Davis A, Song J

A review of the literature indicated that several studies have been reported on the dissolution of gold using iodide/iodine, bromide/bromine leaching systems. Although the reagent costs are much cheaper for chloride/chlorine (or hypochlorite) this system has not been fully evaluated. This study was conducted to evaluate the fundamental chemistry of the chloride/hypochlorite leaching system. The CHEMIX program was used to model the stability of various gold species existing in the solution. The gold dissolution rate at different conditions was determined using gold strips immersed in various mixtures of chloride/hypochlorite. Leaching experiments were conducted to test the extraction of gold from various ores (oxidised and copper-gold ores), showing a promising prospect for this technique in various applications.

Jan 1, 1992

By Penney B. K, Baghdadi A. A

An electron probe micro-analyser, controlled by a dedicated mini-computer,has been operating at Imperial College since 1970. The data assessment capability of the computer was limited and, in order to make better use of the information produced by the analyser, extra computing facilities were needed. Following the initiation of a Laboratory Automation Project at Imperial College involving the use of a central computer linked to laboratory type computers and to further more powerful systems,it became possible to carry out much more detailed and extensive mineralogical analyses by connecting the mini -computer to the Laboratory Automation Network. The paper describes the techniques employed including hardware, software, inter- connection, analysis and operating methods.

Jan 1, 1977

The paper discusses the characteristics of Be-zymianny activity during the last 2500 years. Three periods of increased activity have been identified which are the eruptive cycles lasting for 100-400 yrs. The periods of high activity fall on the fol-lowing time intervals: 2400-1700 yrs ago, 1350-1000 yrs ago and from 1955 ixp to the present time. The 1955-1956 catastrophic eruption after a long period of repose (about 900-1000 yrs) opened a new cycle of activity of the volcano which is continuing to-day. Several decades are distinguished in activity which differ in character and intensity of eruptions.

Jan 1, 1990

By Tapp B. A

To date, few studies have been made regarding the energy requirements of the Australian mining and mineral processing industries. This paper indicates that these industries use a substantial proportion of the total Australian energy input (32.7% in 1971-72 and 36.10% in 1974-75). With the growth orientation of these industries, this input is likely to increase. Data shows that mining energy requirementE varied from 4.22% (of total Australian energy requirements) in 1971-72 to 4.16% in 1974-75. Energy requirements for the total mineral processing industries increased from 28.49% to 31.93% for the same period. The total estimated primary energy input varied from 22.56% to 25.2%, whilst indirect energy use, in the form of electricity increased from 10.16% to 10.66%; in the same period. Analysis of primary energy input data within the processing industries (1973/4) showed that the Iron and Steel Industry consumed 15.03% of the Australian total consumption, Non-Ferrous metals, 5.43%, Cement, 1.64%, and Refractories, 1.59%. In toto this represented 24.57% of the total

Jan 1, 1979

Gallium occurs at above background levels in most samples collected from 11 of the major geothermal areas in the Taupo Volcanic Zone. Concentrations of Ga in the 48 samples ranged from 8 to 144 mg kg-1 and varies widely from place to place within each geothermal area. Gallium is contained within the alumino-silicate structure of clay in the mud, having substituted mainly for Al. Suggested deposition mechanisms for Ga also involve co-precipitation with Sb, As, and SiO2 colloids. Digestion trials, carried out to determine extraction conditions for possible commercial exploitation, showed that heating the mud to 500 - 600¦C for 1 hour followed by acid/alkali treatment gave complete recoveries.

Jan 1, 1995

By McKee DJ

Future mineral processing developments will be of two types. There will be a continuation of the advances of the last 20 years including major increases in equipment capacities, the development of reliable on-line instrumenta- tion, the use of digital computers for automatic control, and the greatly expanded use of in-situ leaching techniques. However, there will also be a need for innovations as the industry faces a different set of problems to those involved in cost and extraction efficiency considerations. These new problems include those relating to energy usage, environmental pressures, and the further development of large low grade deposits and small, high grade metallurgic- ally complex deposits. Present technology does not appear adequate to solve many of these new demands. New treat- ment concepts will be required, and the immediate outlook in this regard is not encouraging. A major research and development task in mineral processing over the next 20 years will be to seek out new ideas and develop them, and this must be pursued with imagination and determination. Both the continuation of the present research pro- grammes and the development of new methods will require a steady supply of highly qualified technical personnel. These people are not being produced in the numbers required, and this situation must be urgently rectified.

Jan 1, 1981

By Seedsman RW, Duncan Fama ME

Mine design procedures will be revolu- tionised by technological developments in computers, software, database construction and management, and numerical modelling programs. Developments in geotechnical databases will be required which utilize geological and geomechanical tests to supply appropriate input for numerical models. Techniques utilizing sedimentological and structural modelling are described. The capacity of current numerical models in mine design is outlined and a program for developing a fully integrated mine design package proposed.

Jan 1, 1987

By Chen J, Zhu D

A detailed study on oil agglomeration of fine metal oxide particles is presented in this paper. The major content embraces several aspects which may possibly reflect the current trends in oil agglomeration such as the effect of chemical and physical parameters, the activation of target minerals and the deactivation of gangue particles, the mechanisim of bridging liquid and the kinetics of oil agglomeration process. Systems of ilmenite-feldspar, manganese dioxide - quartz were seperated successfully through oil agglomeration followed by decantation or flotation technique respectively. A triple mixture of vandium-bearing titanomagnetite ilmenite and feldspar was processed satisfactorily using a composite technology: oil agglomeration-decantation-magnetic concentration.

Jan 1, 1993

By Deverux M

Heavy mineral deposits accumulate on shorelines with interrupted sediment input. Beach deposits, which form on shallowly dipping coastal plains, are most favourable. However, shallow shelves seaward of cliffed coastlines are known to contain economic deposits. Significantgeologicalconditions are defined, from review of the stratigraphic and geomorphic controls on known deposits , for heavy mineral accumulation on the Swan Coastal Plain.

Jan 1, 1986

Boring of a 7.5Km long tunnel under the city of Stockholm commenced in January, 1987. The 3.5m diameter tunnel will pass under the buildings and as no ground settlement is allowed, the regulation for water leakage into the tunnel is very strict. Probe drilling will be carried out continuously ahead of the boring and when water is encountered the rock has to be grouted before passing with the TBM. The tunnelling system enables probe drilling to be carried out during boring with the TBM. This has earlier been a capacity reducing factor as the whole operation has been stopped during probe drilling. The project is using a new generation TBM especially developed for hard rock formations which require higher thrust per cutter to get a high penetration rate.

Jan 1, 1987

The process of resource estimation of large precious metal deposits is illustrated by reference to major deposits now being mined or developed by Placer.The estimation procedure commences with building an appropriate model of the mineralization and proceeds through steps of data validation and geostatistical studies. It is important that the geologists most familiar with a deposit be involved with all stages of the estimate, and also prepare a manual estimate used to validate the kriged resource.Resource estimates are major exercises taking many man-months of work. The most time consuming part of this is usually construction of an appropriate three dimensional geological model. The data base for the resource calculations must be complete and checked for accuracy. The most appropriate estimation method must be selected.

Jan 1, 1990

By McMahon DW

The major components of a mineral reserve estimate for project development purposes are described with respect to sampling, geology, estimation methods, mining factors, metallurgical factors, environmental factors, financial and other factors. Each of these components impact to varying degrees on the recoverable metal or product of a new mining project. The evaluation of a project is a complex process involving the best the profession can provide in terms of geological understanding, engineering ingenuity, metallurgical skills and financial evaluation.

Jan 1, 1983

Prefeasibility planning and cost estimation of conveyor systems has historically been undertaken by comparing fi xed plant transport requirements to that of similar systems in service. This paper describes the development of a prefeasibility conveyor technical design and cost estimation application using Microsoft Excel Visual Basic for Applications (VBA) platform. The application tool known as D-Convey (Dachshund Convey) was developed with the goal enabling the end user: to develop a technical model for conceptualised conveyor systems, to perform economic analysis on the developed technical model, and to conduct a comparative and risk analysis. An Excel VBA based platform was utilised to draw upon both the analytical and graphical capabilities of a spreadsheet. Some of the features of D-Convey system include a revolutionary dynamic graphical help system, known as the 'information pane' in lieu of traditional help fi les as well as the use of familiar graphical user interface elements such as the MS Offi ce 2007 task ribbon. The D-Convey system incorporates material database allowing for mass handling prefeasibility estimation in other industries; it has been validated at a local quarry.

Dec 6, 2010

By Giannini L. M

Optimisation techniques, based on the block model, for solving the optimum pit limit problem were discussed in an earlier paper. Of the available techniques the one based on graph theory proved to be the most attractive. In the graph theory model the vertices represent blocks and the arcs represent the mining restrictions. For large ore-bodies direct application of the graph theory method poses considerable computational and storage problems. Techniques for easing the computational effort by reducingthe problem size were introduced in an earlier paper. Further, significant computational savings can be made by exploiting the structure of the graph. This is done by building the graph up level by level and successively applying the graph theory algorithm to reduce the number of blocks. In building up the graph in this way one needs what is called a "search pattern" to indicate which arcs are to be added as new vertices are introduced. Moreover, as it is essential to keep the number of arcs to a minimum it is necessary to establish a "minimum search pattern".The problem of determining minimum search patterns for any block model and for any wall slope restrictions has not been considered in the literature.The objective of this paper is to present a complete solution to this problem and to discuss, through typical case studies, the application of the associated software developed.

Jan 1, 1988

As a basis for my address to you tonight I thought it might be opportune if we considered the great history of the mineral industry in Australia, and the contribution it has made to the development of the country. While it is perhaps interesting to review the achievements of the past there is also the opportunity to examine the developments of the future.The names generally given to the three periods of man's life on the earth-the Stone, the Bronze, and the Iron Ageand to which should perhaps now be added the Atomic Age, imply the vast importance of the progressive steps in 'man's discovery of minerals and the means of working them. They tell the story of his advance from the flint knife to the bronze celt, and then to the keen-edged iron weapon, and now to the possibilities of the peaceful application of atomic energy. Not only have the stories of gold, iron, copper and tin told a great deal of the history of the progress of mankind, but they have also traced the commercial and industrial growth of Australia over the last century.Gold in the 1850's was responsible for the most significant period of immigration Australia has ever had-when the population almost tripled in the ten years to 1860. Minerals were also responsible for opening up Australia and determining the pattern of settlement. As mineral finds were made, railways were constructed to these fields, then agricultural development followed.Then, as the industrial era started, minerals provided the raw material for Australia's rapid industrial expansion, and they have all contributed to the extent that they have made...

Jan 1, 1960

By N R. Johnson

The overland conveyor at the Los Pelambres mine in Chile is designed to move 8700 t/h of material over 12 km at a speed of 6 m/s while descending 1400 m. The conveyor, which is divided into three segments, is equipped with a braking system that must bring it to rest without producing excessive stresses in the conveyor belt. Retardation and gently stopping a mass of 250 t requires retardation times in the order of 60 seconds. Brakes that can provide this performance require sophisticated controls as well as very high heat absorption capacity. This paper describes the thermal analysis of the braking system, which required the use of novel materials to meet the arduous duties imposed on the callipers and discs.

Jan 1, 2005

By Sheng X. L

The Jurassic coals at Datong are characterised by their strong, massive sandstone and conglomerate roofs which fail suddenly over large areas, crushing pillars and creating destructive windblasts. collapsed areas have exceeded 180,000m2 and windblasts have extended over one km underground and 200m on the surface and have been accompanied by subsidence troughs on the surface. Scientific analysis has researched premonitory signs of caving and the nature of windblasts leading to considerations of alternative mining methods and ways of dissipating the energy of windblasts to reduce their damage and danger..

Jan 1, 1992

By Watson F. G

As an introductory paper of a series on the Melbourne (Australia) Underground Rail Loop extension to the extensive electrified suburban railway system the paper outlines the need for the Loop, legislative background, organizational establishment, engage- ment of consultants, design control, contracts, financial aspects, example of organizational flexibility and certification and transfer of the Loop to the Victorian Railways Board.

Jan 1, 1981

By Aziz NI, Bridgwood EW, Singh RN

One of the major impacts of using modern mechanised systems of mining is the production of large amounts of extraneous dirt intermixed with the Run of Mine output. The paper out- lines a proposed system of utilizing liquid tailings from coal mines to replace imported cementitious materials used in ground control and various other safety measures. A geotech- nical and cost assessment of the proposed system are also included. The paper concludes that it is possible to utilize processed tailings to cost effectively replace imported packing material for ground control.

Jan 1, 1986

By Shining Z

The strength and deformation of more than two hundred coal samples have been tested in the condition of triaxial compression. The regression equation showing the relationship between coal strength and pressure in the pores, as well as confining pressure, was obtained. The appropriate calculation for stress-strain curve was carried out. Further, an analysis shows the variation of coal strength and its modulus of elasticity in methane medium.

Jan 1, 1992