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Samples weighing 0·5 g are fused with sodium hydrogen sulphate, leached with 5 ml. of 4 M nitric acid and diluted to 10 ml. with water. An aliquot of the clear solution is boiled with concentrated nitric acid and then 2 ml. of a phosphotungstate solution are added. After dilution to 10 ml. with water, the solution is heated in a boiling water-bath for not less than 10 min. When cold, the solution is extracted with 2 ml. of iso-amyl alcohol and the yellow phosphotungstovanadate complex is compared with a standard series. Concentrations down to 4 p.p.m. may be analysed at a rate of 100 samples per man-day of 8 hr.

Jan 1, 1971

In line with the recommendations of The AusIMM/AMIC Joint Committee Report in 1981 Isa Mine ore reserves are quoted in proven and probable categories (recoverable ore reserves). Internal reporting considers geological mining and extraction reserves in terms of proven and probable categories. Proven reserves are subdivided into detailed and confirmed ore. External reporting includes a possible ore category (not a reserve). The basis for these divisions is the spatial distribution of sampling data. Proven ore is defined by data 80m apart or less and probable ore by data 80m to 150m apart. Within the proven ore category detailed ore is defined by data 40m apart or less and confirmed ore by data 40m to 80m apart. Kriging is used to provide tonnage and grade information for the currently producing 1100 and 1900 orebodies. Kriged cross sections are initially produced to coincide with existing geological sections and are used for stope design. Stope ore reserves calculations are ideally performed at three discrete design stages, which in order of increasing accuracy are: preliminary design (PD), final design (FD) and ring design (RD). At each of these stages Kriged meshes incorporating the most recent sampling information are produced for reserve calculations. Historically derived mining and extraction factors are applied both to global reserves and individual stope reserves to reflect changes in geological and mining conditions as well as the sequencing of extraction. These factorised reserves are then inserted into the computerised reserves inventory system (RIN). Monitoring of individual stope performance continues into the production stage with input from planning, research, survey and production personnel. This allows actual extraction factors to be derived for comparison with predicted factors, providing some measure of stope performance.

Jan 1, 1987

Mineral Sands - "An Industry for the Future"The mineral sands industry is matched only by the gold industry in relation to its current buoyancy. The strong demand for the various mineral sands products, creates a positive environment in which to review the technical and commercial factors affecting the future of this industry. This conference is clearly being held in the right place at the right time.My role today is to put forward a few ideas that may help Australia to assert its rightful role as a major downstream player in an industry which it has dominated for 25 years as a raw material supplier.

Jan 1, 1986

By M Pomery

BHP’s Western Australian Iron Ore Operations (WAIO) move approximately 250 million tons of ore per annum. The magnitude of the constant changes to the terrain models along with the diverse output and presentation requirements of numerous stakeholders presents significant challenges for the geospatial team. This paper describes how the WAIO Survey team use a combination of technology and optimised workflows to capture, ingest, publish and access large data sets for diverse stakeholder requirements. Machine learning for processing of data and the use of web based systems to track and prioritise task allocation of resources will be discussed in detail, in addition to the changes to the traditional roles of surveyors from the use of automation and mobile technology.

Sep 18, 2023

By Weller K. R, Trahar W. J

The Mount Lyell Company treats some 2.3 million tonnes of ore annually, mined from a number of orebodies on the field. Blended ore is essentially a quartz-sericite schist containing about eight per cent of pyrite and three per cent of chalcopyrite. Four-stage crushing and two-stage ball milling are followe by selective flotation for copper. Pyrite is recovered from the coarse fraction of dopper circuit tailings. A detailed survey involving examination. of 82 samples provided information on the size- by-size behaviour of the principal ore constituents throughout the grinding, copper flotation and pyrite flotation sections of the circuit. Results for the copper and pyrite flotation sections are presented in the paper, and it is shown that over half the copper reporting to the final tailing (5% of copper in the feed) is plus 100 microns and that the major pyrite loss is in the desliming cyclone overflow. These data proVide a basis for assessing potential methods of circuit optimisation.

Jan 1, 1977

By Floyd JM

Pilot plant trials showed the effective ness of the submerged lance SIROSMELT technology for altering the composition of iron blast furnace slags as a preliminary step to produc- tion of formed materials. Mixtures of oil and air were injected into a bath of liquid slag to provide the heat required for melting the additives and to provide very turbulent conditions which resulted in complete dissol- ution of added fluorspar within one minute and almost complete dissolution of silica in two minutes. Sulphur lost during injection was readily made up by addition of pyrite or pyrrhotite. A stable foam could be readily made and broken down and the foamed slag appeared suitable for extrusion or forming into shapes.

Jan 1, 1979

By Johnson M, Wooltorton B

A programme of hydraulic fracture stress measurements conducted in surface drill holes along the alignment of the King River Power Tunnel has provided information of importance to the assessment of the extent of steel lining requirements for the tunnel. A significant horizontal stress field has been detected at a location remote from the power station site, with a corresponding absolute minimum stress magnitude approximating the overburden pressure based on depth of cover. Measurements made closer to the power station site (located toward the bottom of a valley) have revealed an apparently relatively destressed region with minimum stress magnitude less than overburden pressure. The implications of these results are discussed.

Jan 1, 1987

Feasibility is a value improvement process for projects. At any stage in project development, a feasibility study can be undertaken, but although the scope generally remains unchanged the extent of detail and level of accuracy usually increases with time. The main scope elements are a business definition, project description and an execution plan. The studies are designed to assess the potential of the project and to secure funding for on-going examination. Invariably, the investigations loop back to earlier stages to establish more appropriate development criteria but a critical stage is reached when a project construction decision is requested. This feasibility study requires very detailed presentation and analysis to a higher accuracy for the owner(s) and their potential lender(s).

Jan 1, 1997

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

The South Mine, property of Broken Hill South Limited, is situated at Broken Hill, NSW, Australia, towards the southern end of the main lode. The leases (MLs 7 and 8) cover a length of 2400 feet along the lode outcrop and the workings extend, at this date, to a depth of 1940 feet below the collar of the original main shaft and to 825 feet below sea level. Mining operations have been continuous for about 58 years and during this period nearly 12.5 million tons of ore have been mined. The monthly tonnage extracted approximates 30 000 tons in normal times.The ore is a mixed sulphide containing galena and marmatite; the gangue minerals are principally calcite, rhodonite, quartz and garnet. A typical assay for a monthly period is 14.4 per cent Ph, 5.6 ozs Ag, and 11.6 per cent Zn. The whole of the ore is concentrated on the property by combined gravity and flotation methods. The lead and zinc concentrates produced are railed to other centres for the extraction of the contained metals.

Jan 1, 1994

By Adeloju S, McQuade CV, Riley SJ

Metal contamination of sediments can be an issue for minesites discharging water. Water sampling of receiving waters is frequently undertaken. Sampling and analysis of sediment is less common. The variability of receiving environments makes the formulation of a generic sediment sampling strategy virtually impossible. Each situation needs to be carefully assessed before sampling is undertaken. This paper outlines the approach taken for one such survey.The main factors that need to be considered in a survey of surficial sediments are sample representativeness and sample variability. A simple data set from one site within a regional survey is used to illustrate the importance of these factors. The metal content of sediment is shown to vary significantly over small spatial scales.The variability associated with the spatial distribution of samples within a site is shown to be the most significant source of variability in the study. This variability could bias the results of a study if not planned for in the sampling methodology. Taking multiple samples from within each site (sub-site samples) and combining the data gives a more representative indicator of overall conditions than a single sample. The optimum number of sub-site samples to be taken from each sampling site was found to be 15.It is shown that a composite of sub-site samples can give a good indication of the average site metal content, while considerably reducing the sample preparation and analysis effort.

Jan 1, 1998

By Russo S

Metals Refining Operations Pty Ltd (MRO) began refining gold in PNG in 1991 and has undergone continuing growth since then in servicing an everchanging and growing market. MRO's ownership combines PNG Government interests and Golden West Refining Corporation Limited as operator.Features include a very diverse range of suppliers, a full range of technical methods and challenges and the financing and marketing responses unique to a developing country. These areas are examined and documented with special emphasis upon the service needs for the gold industry and future trends and challenges are discussed.

Jan 1, 1997

The Curragh coal mining operation was designed and constructed to produce two coals initially at a rate of 4.3Mtpa. These are a high thermal energy steam coal primarily for domestic electricity generation and a low ash high quality coking product for the export market. Treatment of coals from four seams to achieve this requires a large and complex preparation plant and blending facilities incorporating state of the art technology. This facility was constructed during 1982/83. It has been designed for expansion to 6.8Mtpa capacity. The preparation and handling facilities were built at a cost of approximately A$80 million. Equipment includes 500 plus electric drives with a total capacity of 20 000kw. Commissioning was carried out in three phases : Staging - of the control system Coal Handling Facilities - conveyors, stackers and reclaimers for raw and product coals The Coal Preparation Plant - heavy media cyclones and froth flotation. A period of three months was devoted to the commissioning of the plant before requiring product coal to contract specification. This paper will describe the planning, implementation and results achieved.

Jan 1, 1986

By Kobayashi M

Particulate chalcopyrite samples (78 ~ 98 mole per cent chalcopyrite, screen size fraction from 710 to 250 µm) were prepared by crushing and sieving lump ore samples from 12 locations in the Mt Isa Mine. Measurements of thennoelectric power (which does not involve the passage of a current) were made using a packed bed that was compressed by loading with a weight and placed in a temperature gradienL Details of the apparatus are described.The effect of particle size was investigated by preparing 12 fractions, with mean particle sizes ranging from 605 to 2.2 µm, from one of the ore samples. Values of thennoelectric power decreased with both increasing particle size and loading pressure; however it remained fairly constant for particle sizes above 80 µm, when loading pressure exceeded 3.3 MPa.Measurements of the chalcopyrite samples gave an average value of -260 JlV/K (-248 ~ -268 µV/K) for nine samples and about -290 µV/K for three samples, showing that these samples were all n-type semi-eonductors.

Jan 1, 1990

A resume covering currently accepted views on blasting vibration measurement, human response, and criteria for damage is presented as background information for readers who are not conversant with blasting vibrations. This is followed by sections on vibration level estimation and blasting techniques to control vibration. Emphasis is placed on making use of the scatter in the delay intervals of half-second delay detonators, the use of smaller explosive charges for early delay numbers, and the non- use of zero-delay (instantaneous) detonators in cer`a. n cases.

Jan 1, 1976

By Hashimoto H, Arai Y, Sikong L

For utilization of solid carbonaceous materials produced in processes of cracking heavy oil, such as petroleum pitch, as powder fuel, it is necessary to develop a process for fine grinding of these materials. It is known that grinding' additives are effective for fine grinding of cohesive and heat-sensitive materials such as petroleum pitch, therefore in this study, effective methods for fine grinding of petroleum pitch with some grinding additives were investigated. Experiments were carried out by using comminution kinetics based on mass balance. From the results of the investigation by using a batch ball mill, it was found that sodium stearate, calcium stearate and carbon black were effective additives for the improvement of grinding efficiency. Optimum concentration of the grinding additives was also found to give a required particle size of products. Concerning to the action mechanism of these additives, it is considered that the additives which adhired to, or were absorbed on the surface of petroleum pitch particles not only prevented cohesion of the particles but improved dispersion of the particles as well. From the results of the investigation by using a laboratory screen mill which is a representative built-in classifiered impact crusher, carbon black was found to be an effective additive for the improvement of grinding efficiency and mill performance. It is also considered that the improvement of classification efficiency by carbon black affected the mill performance.

Jan 1, 1987

By Geisler P, Sutherland P

The technical limits for high-pressure transport of large particle solids by means of sludge pumps, piston pumps or the like lead to the development of the pipe-feeder system. The pipe-feeder is a type of pressure lock in which the high-pressure pump itself is not in contact with the solids. Simultaneous operation of the three chambers with corresponding control of the valves allows continuous flow in both the primary and secondary circuits. Initially the pipe-feeder was used only for the transport of solids. Today it also operates with great success in central mine cooling systems, serving as an alternative for high-pressure/low-pressure heat exchangers or Pelton systems. In addition to the technology applied up to now, the pipe-feeder is also capable of transporting ice slurry, thus increasing cooling output consider- Ably.

Jan 1, 1991

The paper describes the progress made in the last decade with the introduction of comprehensive monitoring of the mine atmosphere into U.K. collieries. Brief descriptions are given of the various portable and fixed point instruments which have been developed for this purpose and the methods available for transmission of information to the surface are also discussed. The paper also outlines some of the research work being carried out both in the laboratory and underground on the development of alternative methods of fire detection. Some of the results from this work are illustrated and discussed.

Jan 1, 1981

This paper describes the application of the Total Productive Management (TPM) technique as a performance improvement initiative for a coal mining operation. It discusses the objectives of TPM, with the driver for improved production performance being the Overall Equipment Effectiveness (OEE) of the equipment or process, and with the development of "ownership" as the behavioral approach to equipment management and continuous improvement through cross-functional and area-based teams. It illustrates the concept of equipment management as defects management.The scope for application of TPM to the coal mining industry is immense. The harshness of the operating environment can be a major generator of equipment defects, and a current paradigm in the industry accepts these defects as an unavoidable outcome defining maintenance costs in this environment. However recent benchmarking studies have highlighted that maintenance costs per operating hour in some mining operations are more than double the vendor's estimate of "best practice". The paper refers to these studies which also compare maintenance costs of fixed and mobile plant and equipment to "best practice" outcomes in comparable process industries.

Jan 1, 1998

By Meyer C. F

The increasing use of continuous miners in the extraction of high coal seams has amplified the need for enhanced ventilation systems in the headings. Owing to larger face dimensions and higher production rates, more ventilating air is required to effectively dilute liberated methane to acceptable concentrations. However, the increased air quantities raise and entrain greater amounts of dust, to which the operator is subjected. Various methods (eg sprayfans, on-board scrubbers and jet fans) are used in various configurations and combinations to ventilate the headings. These arrangements generally result in a complex air flow pattern, which complicates achieving an optimum balance between diluting methane and minimising dust capture. In order to cost effectively investigate and propose solutions to this problem for the South African coal mining industry, the Division of Mining Technology has embarked on an extensive work program to evaluate various ventilation methods presently in use. Four currently generic ventilation patterns in various heading scenarios have been simulated using the Computational Fluid Dynamics (CFD) computer program. Evaluating these outputs against a predetermined set of criteria allows the best system for a particular situation to be chosen. The program also facilitates fine-tuning of an adopted system without incurring the cost and inconvenience of doing such tests in situ. This process not only provides solutions at significantly reduced costs, but also yields deeper insights into the factors affecting heading ventilation than hitherto possible.

Jan 1, 1995