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By Grieveson P, Rajakumar V

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

Jan 1, 1991

By Rowe P, Rogers D, Warren M

Pressure cyanidation of the minus 10 micron slimes fraction of the Fimiston flotation concentrates for the recovery of gold values has been evaluated as an alternative processing route to the roasting and atmospheric cyanide leaching of the calcine. Laboratory and pilot trials have demonstrated that gold extractions of greater than 94 per cent can be achieved at cyanide consumptions of 12-24 kg/t and oxygen consumptions of 0.1-0.3 Nm3/t with total pressures of 1000-2000 kPa. Economic and operational assessment of several reactor configurations suggests autoclaves may be preferred over pipe reactors at treatment rates of 10 t concentrate/h.

Jan 1, 1996

Excavator output rates given in Makers' catalogues are sometimes based on favourable operating conditions. Mine operators and planners are more interested in the Effective Hourly Output in normal operation (Qe) a plant system can give hour by hour and year after year in a particular application. The number of hours mining plant will be available for normal operation will be less than the annual total of 8760 h. The number of the available hours which can be utilised at Qe will depend largely on the number and types of units in the plant system, the manners in which they are applied and the nature of the deposit in which they work. The emphasis herein is on continuous systems for deep stripping with BWE's as the primary excavator. Examples and suggestions are given for the annual hours at Qe for some BWE systems.

Jan 1, 1981

Green policies have gained momentum since the 1972 Stockholm Environment Conference. The environmental movement has influenced political initiatives both in New Zealand and abroad. Governments and international institutions have addressed local, regional and global environmental issues with varying degrees of success. New Zealand so far has not supported the United Nations' call for sustainable development in a,consistent manner.New institutions and new rules for resource management mean there are opportunities to look after the land in different and more ecologically sensitive ways than has happened in the past.The increasing influence of regional councils in resource management planning will have important implications for mining and mineral exploration. These trends are discussed and possible future events outlined.

Jan 1, 1990

By Hirose K, Itakura K

A new global stiffness matrix evaluates the performance of powered supports by estimating and comparing the global stiffness matrices of ten different types of powered supports with lemniscate linkages, each support having its own deformation characteristics. Expanding the global stiffness matrix allows the implementation of a finite element scheme to analyse the interaction between the powered support and the strata around the coal face.The evaluation of performance by the stiffness matrix method shows that 4-leg chock shields possess both the desirable convergence and shear deformation stiffness properties. The finite element analysis also confirms that 4-leg chock shields present well balanced performance for controlling strata around the coal face.

Jan 1, 1991

By C. P. BATES

In November 1969, New Zealand Steel Ltd pioneered the commercial use of the SL/RN solid fuel direct reduction process to make sponge iron as a feed material for electric arc furnaces. Serious process problems with the use of green balls and coal injection were progressively overcome. The process was developed by New Zealand Steel along a radical route, of feeding the fine grained raw ironsand concentrate and coal directly to the kiln. Contemporaneously with this development of direct reduction, steelmaking process innovations were made that enabled the arc furnaces to operate successfully with the high volumes of acid slag.

Jan 1, 1980

Rock bolting provides a supplement or alternative to conventional timber and steel supports. The tensile strength of the bolts lies within a range established by manufacturing quality control. Rock bolt testing determines the ability of the rock, anchor and individual bolt as an assembly to accept load. The.test is performed to the yield strength of the bolt or anchor and deflection is observed. The anchorage index, inches deflection per 1000 lb load increment, is a measure of anchorage quality. This allows comparison with anchorages under ideal conditions. It also permits comparative assessment of roof bolt anchors in a particular environment.

Jan 1, 1971

This paper discusses recent ore reserve methodology at the Woodlawn base metal Mine in New South Wales. The ownership of the Mine changed hands in 1987 and a number of revisions to ore reserve practice were instigated by the new operators. While the overall modeling and calculation procedure remained essentially unaltered, the modifications and revised assumptions significantly increased the ore reserve. While general ore reserve procedures are discussed in this paper, it is the impact of these changed assumptions on the reserves which is our main focus.

Jan 1, 1990

With the sinking of the No. 3 Shaft and the erection of a changehouse nearby, a sub-brace level structure was provided incorporating a time office, underground foremenÆs office and lamp room, in conjunction with a covered walkway, ambulance room, fire station and waiting brace.

Jan 1, 1957

There are three major human resource management activities which, depending on how well they are done, impact on the performance of people and therefore the bottom line. These are: ò recruitment; ò training and development; and ò performance appraisal. Most sizeable organisations would say they are involved in all three, but there are many more that would admit that their human resource management practices are limited to recruitment. If we concentrate on the organisations that currently undertake all three, we have to ask, `Are they using different systems/benchmarks for each activity, or is there congruence between the activities?'. Our experience is that most organisations use different systems/benchmarks. The end result is: ò one set of criteria to recruit staff; ò another to identify their training needs; ò and yet another set of criteria to measure their staff's Performance.

Jan 1, 1995

By Gillies A. D S, Supriyadi

The landed cost of coal to the international customer is a major parameter which determines market competitiveness. Rail, port and shipping charges represent 30 to 50 per cent of landed costs for Australian mines selling to Asia. This prop

Jan 1, 1994

By Riley TW

This paper describes a Process Simulation Package for modelling the steady-state operation of a mineral processing plant. There are two levels of input allowed into the package. The first allows simple manipulation of the process models within a defined modular format which enables a wide range of process systems to be simulated. "The second level of input is via a Command file which allows plant models to be defined and changed without reference to the code or the requirement of any recompiling of the programme sources. The Command file interface was designed for use by metallurgists and assumes a sound knowledge of the system being modelled. As such it is an effective tool for metallurgists rather than a user friendly generalised package for the layman.

Jan 1, 1985

This paper discusses basic practices of operation applied to raise drilling. It draws attention to critical areas that tend to be neglected. A brief history covers development of raise drills. The elements of the equipment, derrick assembly, drill string and reamers are ex- amined. Particular emphasis is on the drill string. It is concluded that manufacturer and operator can benefit each other by closer interchange of ideas.

Jan 1, 1977

By Williams RJ

This paper presents an overview of the design and development , application to date and potential of a real-time return gas monitoring system.Initially developed as an ACARP/Industry funded project, whose prime aim was to create a `turn-key', prototype, stand alone, real-time, Return Gas Monitoring System (RGMS) capable of providing quantitative assessments of gassiness levels on a shift by shift basis, enabling unusual gas emission patterns to be readily flagged.

Jan 1, 1998

By G D. Carman

White Rock is a reduced tungsten-tin skarn deposit near Rye Park, New South Wales. This abstract summarises the depositÆs mining and exploration history, and current exploration by Paradigm Metals Ltd targeting an economic resource at the deposit. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

The Mount Morgan massive sulphide body occurs in a volcanic sequence of Lower or Middle. Devonian age, which is subdivided in the mine into "Upper mine porphyries", "Banded mine sequence", and "Lower mine porphyries". This sequence is intruded by latite, Mount Morgan Tonalite (360 million years), and late Permian dykes. Distribution of macroscopic ore textures and minerals in the orebody are discussed and evidence is presented indicating the pre-Tonalite, Devonian age of the orebody.

Jan 1, 1974

No paper available.

Jan 1, 1996

Mixers are commonly used for the transfer of oxygen in gas-liquid-solid reactions in minerals processing. The process rate is usually controlled by two steps: gas-liquid mass transfer and reaction kinetics. Some examples are described along with the factors used for analysis of the mass transfer design problem. Typical oxygen rates and appropriate types of aeration systems or mixers are reviewed. The commonly used Rushton turbine has limitations in a number of mineral processes. The development and characteristics of the LIGHTNIN A315 axial flow gas dispersion impeller are described. Some practical examples which highlight its advantages are briefly described.

Jan 1, 1992

CONTENTSIntroduction.Ore Bodies.Variations in Ore Dressing Practices.Stage I .Gravity Concentration for the production of a Lead Concentrate. 1909-1918.Stage Il Gravity plus Flotation Treatment for the production of a Lead Concentrate and a Zinc Concentrate. 1918-1929.Stage III All Flotation Treatment for the production of a Lead C~mcentrate and a Zinc Concentrate. 1930-1939General Summary - Stages I, II, III.Stage IV Gravity plus Flotation Treatment for the Production of a Lead Concentrate and a Zinc Concentrate. 1939-1947.1. General.2. Notes on Ore Dressing Practice.A. Gravity Section - Re~oval of Free Galena.B. Secondary Ball Mill Grinding Section. .a. Mineral Association.b. Composite particle problem.c. Degree of grinding required.d. Free Gangue Minerals in Table Tailing.

Jan 1, 1948

Backfil ling of excavated Sub Level Open Stopes has been underway since March 1989 and as at December 1992 some 1 100 000 cubic metres of Cemented Aggregate Fill have been placed. During these three years significant developments in fill quantities, types and cost have taken place.Operational improvements have reduced the quantity of Cement Aggregate Fill by 40 per cent. These results have been achieved by:ò rescheduling stopes,ò designing smaller primary stope, and ò use of uncemented rockfill.Unit cost for Cement Aggregate Fill have fallen in the order of 50 per cent through:improving fill hole reli ability,simplified barricade construction procedures, reducing the cement content,ò substituting dune sand for deslimed mill tailings, ò improved maintenance at the Backfill plant, and ò renegotiated site freight agreement.This paper will review the historical developments of backfill use at Olympic Dam.

Jan 1, 1993