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By Guoqing Cao, Xinghong Wang, Fuqiang Liu, Rong Shen, Xiaoping Yuan

In this paper, an approach is proposed to monitor the rate of lump coal based on image processing. Using this method, we effectively improve rate of lump coal on comprehensive mechanised coal face.

Jan 1, 1998

By P W. Cleary, M D. Sinnott

Cross-belt cutters are commonly used for sampling coal. They are generally cheaper than falling-stream cutters, particularly when a cutter must be retrofitted. The major mechanisms thought most likely to lead to sample bias are being investigated by discrete element modelling (DEM) in a project funded through the Australian Coal Association Research Program. This paper describes a benchmark run and the current direction of research.

Jan 1, 2008

Engineering availability of the 120/200 tonne Wabco haulpak fleet at Mt. Whaleback was in the mid fifties and unstable. The project to achieve a reliable 66% during 1980 highlighted "plannable" maintenance, short cycle scheduling, condition monitoring, backlog control, and, above all, the importance of involving all affected people. It is not sufficient for consultants to design systems and make them work. The people who use the system must understand it, support it and "own" it. In this way, they will develop it and improve results after the outside help has been withdrawn INTRODUCTION In early 1979, PA proposed a programme to improve engineering availability of the Mt. Newman Mining fleet of 70 Wabco haulpak trucks of which 53 were 120 tonne and 17 were 200 tonne units. (Subsequently five 200 tonne trucks from Hamersley Iron were added to the fleet). The ore truck workshop was also responsible for 75 tonne trucks used as water trucks and general purpose vehicles. The need for action was clear. The fleet was achieving availability in the "mid fifties" with wide variations indicating that the fleet was becoming unreliable. Projected tonnages required a reliable 66% availability to be

Jan 1, 1982

Quality Assurance has become a buzzword amongst governments and industry. Notwithstanding the world class work done by its committees in developing codes of ethics and of practice in field geological handbooks, mining cost estimation handbooks, and reserve estimation, the AusIMM could better prepare its membership for QA. MICA could provide a simple set of guidelines to enable consultant members to develop their own QA procedures manual conforming to AusIMM Codes and to IS09003, and AS3903.

Jan 1, 1994

By A S. M A Haseeb

Zircon is the second in abundance among the heavy minerals occurring in the beach sand along the coastal belt of Bangladesh. In this study a detailed characterisation of Bangladesh zircon extracted at the pilot plant of the Bangladesh Atomic Energy Commission at CoxÆs Bazar has been attempted using chemical analysis, X-ray diffraction and optical microscopy. From the chemical analysis it is found that Bangladesh zircon has a purity of 95.88 per cent. The main impurity in Bangladesh zircon is titanium oxide (3.01 per cent). This is followed by iron oxide (0.42 per cent). A number of other oxides are also found. Microscopic study revealed that Bangladesh zircon has an elongated, prismatic shape with pyramidal termination in about half of the grains while the rest are more or less rounded. Some fractured and irregular grains are also found. Bulk sample of Bangladesh zircon in the as-received condition shows a yellowish brown color. However, individual zircon grains are seen to be almost colourless and transparent under polarised light. XRD study confirmed good crystallinity in the sample. Under the microscope it is found that zircon grains constitute 94 per cent while total impurities amount to six per cent in Bangladesh zircon. This result agrees fairly well with the chemical analysis results. Microscopic study identifies oxides of titanium (both rutile and ilmenite) to be the main impurity, in conformity with the findings of chemical analysis. Further, monazite was also identified as an impurity under the microscope. An iron bearing coating is also found on a few zircon grains. Most of the impurities found in Bangladesh zircon exist as discrete minerals.

Jan 1, 2000

By Howell IJ, Kirsopp R

In June/July 1981 Mount Isa Mines Limited was confronted with a crisis situation in the crushing operation of the Lead/Zinc and Copper Concentrators. Three crusher mainframes developed serious cracks in the upper rim area. The type of cracking indicated that major failure of these mainframes could be imminent. Operational crushers could not be sensibly inspected and it was therefore assumed that more than three mainframes were seriously cracked. The crisis was averted as described in the following text.

Jan 1, 1978

The treatment of steels with acid solutions for the removal of oxide products represents possibly the largest outlet for chemicals in steel processing. Organic pickling inhibitors are required to prevent base metal attack by these acids otherwis

Jan 1, 1980

Thank you for that introduction and especially thank you to the organisers for inviting me. I've had a considerable interest in this area and I've had the advantage of an education from Neil on the subject of offering documents as a result of our collaboration together on the Securities Information Review Committee.

Jan 1, 1989

In early-1989, subsidence due to voids at the top of previously filled stopes and stopes awaiting filling,began to threaten the 15 level fill conveyor horizon. This together with the need to maintain production targets meant that a method was required to significantly increase fill placement.Alternative methods of placing dry fill underground were investigated. One option was to drill 200 mm boreholes from surface directly into stopes 600 - 800 metres underground. A drilling program was successfully undertaken, and resulted in the placement of more than 800 000 tonnes of dry aggregate fill via four boreholes.This paper details the drilling program undertaken and discusses the difficulties encountered, the fill placement system and the project costs.

Jan 1, 1992

By M Thomas, S Lambert

The Tugun Bypass Tunnel in Gold Coast, Australia was constructed using diaphragm walls with the top-down cut-and-cover method to allow simultaneous construction of an airport runway extension above the tunnel, whilst excavation of the tunnel continued underneath. The tunnel was built in an environment of high groundwater table and deep deposits of alluvial and estuarine soils with the toes of the walls founded in soil deposits. There was a potential risk for differential settlements to occur between the diaphragm wall panels, caused by the runway fill placed over the tunnel roof during excavation. Dewatering within the diaphragm walls was required to facilitate the construction of the tunnel. The tunnel was also built in an area where environmental considerations were of great importance. Three-dimensional numerical modelling was undertaken to predict the differential settlements of the tunnel with considerations of varying subsurface profile, staged excavation and dewatering, non- uniform surface loading and complex soil-structure interaction. Field instrumentation and monitoring was implemented to confirm numerical predictions.  

Jan 1, 2008

By C Li

Removal of gangue minerals from ilmenite concentrates can beaccomplished by relatively low temperature roasting in controlled gasatmospheres to selectively enhance the magnetic separationcharacteristics of the ilmenite. At roasting temperatures below 800¦C the magnetising reactions are often not consistent with phase equilibria considerations. Metastable phases can nucleate and control the roasting products. In weathered ilmenites the phase assemblages and microstructures in the altered ilmenite grains can influence the roasting reactions. In this paper we give an overview of the phase chemistry of chemically weathered ilmenites and of metastable phases formed by low temperature roasting. We also report the results of roast experiments conducted in a neutral gas atmosphere. Major increases in magnetic properties after short roasting times at low temperatures were obtained for a range of ilmenite concentrates. For example heating a secondary ilmenite concentrate from Western Australia for 15 minutes in nitrogen at 600¦C gave an increase in the three kilogauss magnetic fraction from three to 92 wt per cent. The solid state phase changes accompanying the inert atmosphereroasts were characterised by combining elemental analyses withquantitative phase analyses of the ilmenite concentrates and their roast products. It was found that the phase reaction that is principally responsible for the increase in the magnetic properties of weathered ilmenites involves a transformation of disordered ferrous-containing pseudorutile to an ordered ilmenite-hematite solid solution containing typically ten to 35 mole per cent of the hematite component. Examples are given of the application of the inert atmosphere roast to effect separations of ilmenite from gangue minerals.

Jan 1, 2001

As an older member of The AusIMM, I received my 30 year æPearl AwardÆ in June and had my 50th birthday two weeks ago, I am honoured to be here today. I thank those responsible for their confidence in me and in my ability to hopefully hold captive a broad group of individuals who are here as equals, sharing an interest, no a passion in blasting technology and associated works à over the two days you will hear some excellent operational and technical presentations I am sure. But today I will digress; I want to talk about the importance of leadership and how it indeed can be the catalyst for success, improvement and change. There has been much written about leadership, its principals, the charismatic leaders, the doÆs and donÆts and so on à and I for one am not about to give you the Holy Grail; there are many experts with greater wisdom than I on this subject matter. What I do want to do is explore the application of this passion to examples within the world stage and some examples drawn from my experience in mining.

Jan 1, 2007

The basic principles of mineral valuation were recognised and propounded at the beginning of this century and have remained virtually unchanged since then. Valuation is seen as a two part process commencing with a technical examination of the mineral property followed by a manipulation of the results of the technical examination in order to determine the monetary value of the project. A thorough and competent technical examination was seen then and remains now as the essential but not sufficient foundation for reliable valuation. All authors stressed the need to maintain the integrity of the data base and to ensure adequate coverage of all relevant aspects. The monetary valuation process through most of the first half of this century was mainly based on the Hoskold two rate method, derived from the formulae for valuing annuities but modified to provide explicitly for recovery of capital. Though the basic principles of valuation have not changed significantly, the means of implementing the components of the technical examination, the styles of deposits being evaluated and the mechanisms of monetary valuation have changed dramatically. Despite all the technological improvements, however, mineral

Jan 1, 1995

By M Hitzman, E P. Nelson, J Skarmeta

The Coastal Cordillera of northern Chile hosts the youngest and possibly best preserved iron oxide copper gold (IOCG) belt yet discovered and includes important deposits such as Candelaria and Mantoverde. The spatial and temporal relationships of hydrothermal alteration and mineralisation (Fe and Cu-Au) related to structural and lithologic features were investigated through geologic mapping and petrographic and geochronological studies along two W-E-transects crossing the Coastal Cordillera to the north of Vallenar. The project aimed to determine vectors for district-scale and regional exploration. Along with magnetite-apatite deposits (Central Iron Belt) and manto-type copper deposits, the IOCG deposits are hosted in a N-trending volcano-sedimentary sequence formed in a Jurassic to Early Cretaceous arc/back-arc setting (Sillitoe, 2003; Ramos and Alemßn, 2000). Calc-alkaline plutonic rocks intrude and metamorphose the volcano-sedimentary sequence, and become progressively younger from west to east reflecting a shift of arc magmatism (to Paleocene in the far east). From west to east along the Agua Grande-Chehueque profile, four domains of different economic potential are recognised. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Almost all industrial products, such as buildings, cars, plastics, railways, radio and television sets, computers, and others are made from materials extracted from the Earth. Earth is main resource of energy and up to now; the energy has been derived mainly from natural resources. Mining industry has significant influence to the nature, sometimes evokes a devastation of nature. On the other hand we have got a lot of nice examples that good preparation, sensitive mining practice and consistent reclamation can minimise the negative effects. All the mentioned problems calls for effective tools for mine design, mine operation and mine reclamation. Third millennium brings next challenge given by advances in information and communication technology. The development of very sophisticated software tools provides to technical systems some features of autonomous æthinkingÆ and intelligent behaviour. We can find large effort and a lot of scientific papers reflecting last advancement in science and technology and providing inspiration for new mining technology of third millennium called Intelligent Mine. Some aspects related to creation and utilisation of æIntelligent ModelsÆ as a background of æIntelligent MineÆ are presented and discussed in this paper.

Jan 1, 2003

The BHP Steel Group embarked on a Total Quality Control (TQC) programme in 1984 in response to enquiries from a major customer regarding procedures for quality in materials supply.The TQC initiative has been adopted by all seven Divisions of the Steel Group and covers a broad and comprehensive range of management and workforce improvement initiatives.The development of the TQC initiative in the Collieries Division of BHP Steel over the past eighteen months has resulted in important experiences and leanings.

Jan 1, 1991

By W J. Bruckard

In Australia, ilmenite is produced from beach sand deposits. These deposits contain varying quantities of the valuable minerals zircon, rutile and ilmenite, along with a variety of other minerals. The valuable minerals are upgraded using combinations of gravity, magnetic and electrostatic processing techniques to yield high-grade products. One of the penalty elements present in ilmenite concentrates is chromium, present mostly as chrome spinels. This mineral is particularly difficult to separate from ilmenite, as the properties of the two minerals are very similar in relation to the traditional separation processes. While the deposits which have been treated in Australia in the past have had only low levels of chromium present, many of the newer deposits contain much higher levels of contamination and, thus, there is an increasing need to develop robust processes to separate chrome spinel from the ilmenite. Flotation, which is a unit process with the potential to solve this problem, has surprisingly received little attention for this application. The literature suggests the research effort to characterise the general flotation properties of chromite (chrome spinel with high chromium content) has been extensive and a substantial amount of data is available. However, the problem of separating a small amount of chrome spinel from a large amount of ilmenite requires a different approach to that from separating chromite from siliceous gangue, which has been the main commercial focus of chromite flotation in the past. Much of the work done has been fundamental in nature and the results obtained are fairly inconsistent, as is the testwork completed at batch and pilot plant scale. While these inconsistencies have been attributed to the variable composition of the mineral, there is little evidence supporting this premise. Just as chrome spinel and ilmenite have similar physical characteristics, the flotation response of both minerals is also similar. This paper reviews the literature relating to the flotation of chrome spinel and presents a considered approach to the development of a robust flotation method to separate chrome spinel from ilmenite.

Jan 1, 2001

In Finland fogging in mine ramps is a common problem. Fog forms when warm and humid exhaust air moves upwards the ramp, where the skin temperature of surrounding wallrock decreases to about 10¦C. Changes in fog thickness and lengths of fog-filled parts of the ramp depend at least on climatic conditions outside, diesel equipment usage in the mine, and the length of working sequence at a time. In this study fogging problems in three different mines, namely Orivesi mine, Louhi mine and PyhSsalmi mine, with different ore types, different layouts, and different depths are presented and compared. All these mines use diesel equipment and the ramp is used as an exhaust air route. In two of these mines the ramp is used as a haulage road and in the other for supply and repairing, checking, and surveying purposes. Measurements of humidity, temperature, air velocity, and dust content were performed in these mines. The measurement results, as well as field observations are presented, compared, and discussed. The results show that fog is observed in areas with high relative humidity values when air temperature and dew point temperature are less than 3¦C apart from each other. Air velocity values were high in many areas. In addition, measured particle concentration values were mainly high in areas, where fog was observed. A short literature review of recent fog formation studies is also presented. It demonstrates the complicacy of the fog formation process. Similarities and differences concerning fog problems in the ramps are found and presented. As already a lot of new information is gained, the continuation of research is considered plausible to find more economical ways of solving and preventing this problem in the future.

Jan 1, 2005

By Ruffles B. R

A computer simulation has been developed to model the flow of copper ore in Isa Mine. It simulates extraction of copper ore from the 1100 orebody by load-haul-dump (LHD) units to ore passes, haulage from chutes on 19 level by Rockflo trains to crusher bins, crushing and hoisting. It can assess in terms of the tonnage and head grade of ore hoisted, the effect of varying operating strategies, as well as measur- ing shortfalls in required capacities of any of the operations (extraction, hauling, crushing and hoisting). The simulation was designed as a modular, deterministic, steady-state model with parameter input allowing complete flexibility in its use. Queuing theory is used extensively to evaluate the effect of interference at potential bottlenecks. The model has been used to determine the effect on production of varying train sizes, maintenance policies on the haulage circuit, orepass capacities, and extraction operations.

Jan 1, 1974

By Bilodeau M. L

The paper describes a model which has been developed to assess the economic charac- teristics of base metal investment in Canada and the effects of past, present and possible future sharing systems, particularly mining taxation systems, thereon. The model is illustrated by applying the 1976 Canadian tax system to the economic characteristics of base metal discoveries made in Canada during the 1951-1974 period.

Jan 1, 1977