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By F Mwijage

"The benefits of measuring blast movement to reduce ore loss and dilution have been recognised by many people for many years and various methods have been used with limited success. Geita Gold Mine is running the pilot study on the blast movement monitoring (BMM) system which is a revolutionary method developed and patented by the University of Queensland and Blast Movement Technology (BMT). The system consists of directional transmitters placed within the shot prior to blasting, which are then located after the blast with a special detector and then the data is processed with purpose-designed software.As part of continuous improvement on grade control, Geita Gold Mine is running a research project in all operating pits with the objective of: quantifying the three-dimensional blast muck pile movement and finally utilise the movement data to define post-blast ore polygons and incorporate the movement dynamics during block modelling,quantify the potential savings for ore loss and dilution,improve mine geologists knowledge of blast dynamics, andstimulate greater co-operation between drill and blast engineers and geologists to achieve optimum blast designs.To any operation with selective mining, it is critical to the economics of an operation to control ore loss and dilution; getting it wrong will result in significant lost revenue. Implementation of ongoing pilot study on electronic balls as determinant on blast movement dynamics on ore would be of longer term solution and big investment pay back.CITATION:Mwijage, F, 2012. Pilot study on blast movement monitoring at Geita gold mine, in Proceedings Narrow Vein Mining 2012 , pp 49-58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

Many parameters are important when considering the performance of a concentrator. These include metallurgical performance, such as throughput, metal recovery and final concentrate grade and operating costs, such as power consumption, water usage, reagents and spare parts. In most operations the objective is to maximise metallurgical performance and minimise operating costs, ideally without a large investment in new capital items. A number of projects have been carried out at Newcrest MiningÆs Cadia Valley Operations (CVO) with the aim of improving metallurgical performance and minimising operating costs. This paper focuses on the installation of newly designed flotation mechanisms in various cells in the Cadia flotation circuit and describes the effect these changes had on performance and operating costs.

Jan 1, 2009

By B Indraratna, A Dey

The surface geometry of a rock bolt plays a very important role in the rock/resin/bolt load transfer mechanism. Very little work has so far been reported on the influence of the bolt surface geometry on the bolt/resin interface failure mechanism. This paper examines the behaviour of bolt surface roughness under constant normal stiffness condition in the laboratory. To study the shear behaviour of the bolt/resin interface a series of shear tests with an initial normal stress between 0.1 to 7.5 MPa has been conducted on the flattened bolt surface of two most popular bolt types currently being used in Australia. Bolts with deeper ribs offered better shear resistance at low initial normal stress conditions whereas bolts with shallow and closer ribs offered better shear resistance at high normal stress conditions. The maximum dilation occurred at a shear displacement of 60 per cent of the rib spacing irrespective of the bolt type and depth of the rib.

Jan 1, 2000

Felspar occurs in association with quartz in the Broken Hill lode pegmatites and is brilliant green, greenish white, and white in colour. The pegmatites occur mainly in the walls in sporadic patches, parallel to the general dip of the ore deposit. The occurrences are of no economic value.Deposits of marketable felspar occur in pegmatite in a number of localities around Broken Hill, New South Wales.The majority of these are in the form of an irregular outcrop, usually of tapering length and depth. The maximum depth of any deposit yet worked in the district is about 40 ft. The felspar is occasionally contaminated by "blows" of quartz, mica and beryl, but the two latter are profitably marketable when separated.Felspars vary in colour from pink, through grey to snow white, and the colour is not indicative of the mineral content. The largest deposit at present being worked is the Egebeck quarry, about 14 miles south of Cockburn. It is a prominent outcrop, roughly circular and about 150 ft. in diameter, covered by one to three feet of overburden.The felspar is mainly massive, but contains some cleavage planes at approximately 90°. Intrusions of quartz and mica occur in patches, but the deposit appears likely to improve in size, regularity and quality below the present working floor.COMMERCIAL USES.Commercial felspars are mainly used in the ceramic industry, for which a high-grade potash felspar is required.The dental industry requires limited amounts of soda felspar with a very low Fe20s content. The poorer grades...

Jan 1, 1946

After reviewing the many excellent papers being delivered here, it is apparent that we are all concerned with the same general subjects of commodity agreements, international cartels, and anti-trust problems as well as the impact of governments on resource management and minerals pricing. Accordingly, as a relative newcomer to the mining business, I feel that my most meaningful contribution can be made by taking a more philosophical look at the future of our system of democratic capitalism. Unfortunately, governments the world over seem intent on jeopardizing the high standards of living resulting from the Industrial Revolution and furthered by the emergence of its by-product, capitalism. This tendency is particularly germane to the basic natural resource field, since government regulations, controls, and intervention in mining far exceed even the constraints normally imposed on hard-pressed consumer-oriented businesses. Increasingly, many governments seem to feel that natural resources no longer belong to private individuals but rather are the property of the state to be developed in a regulated manner and usually in a way directly contrary to the functioning of the free market system.

Jan 1, 1978

By Wu Y, Qu Q

The Central Coal Mining Research Institute has developed the MAE acoustic emission monitoring system, the BD4-1 portable acoustic emission monitor and the MRB rock burst monitoring system. In the MAE system there is an IBM-PLAT, a receiver and 16 channels and the investigating range is 100 m. The main functions are detecting acoustic events from the working faces, periodically making statistics, prints, displays and storing of the results, and performing the off-line process such as drawing the curves of acoustic activity. The BD4-1 instrument has four channels, it works for more than 24 hours continuously, and keeps the data for more than 30 days after power tum-off. The BD4-1 is suited to the monitoring for a long or a short time as a fixed point where the system is invalid, especially to the monitoring of the acoustic activity promoted by the blasting. There is an IBM-PC/AT, a receiver and 16 channels spread 10 km in the system MRB. The system could on-line collect microseismic events throughout the whole mine, calculate the source location and the energy, and off-line draw the seismic activity draft of time-based or distribution in space. In practice, the forecasting is successful by using the acoustic emission and microseismic monitoring system and the portable instrument.

Jan 1, 1991

A number of cooperative studies have been carried out as preliminary work for drafting a standard for application of granulated slag sand for concrete, and the following conclusions were reached 1 The ten kinds of granulated slag sands pro- duced in Japan satisfy the national standard for fine aggregate in terms of physical and chemical properties. 2 Mortar and concrete tests conducted with granulated slag sand revealed that, although with slight differences in the extent, gran- ulated slag sands used in these tests were applicable'as fine aggregate for concrete, 3 The pumpability test by a concrete pump carried out on concrete with two kinds of now commercially available granulated slag sand demonstrated that the pump pressure feeding is applicable in the same manner as in the case of ordinary concrete. These tests permitted' preparation of a draft standard for application of granulated slag sand, and the results formed the first step toward utilizing this material as a sub- stitute for natural sand.

Jan 1, 1979

By Weir D. R, Doyle B. N

The Sherritt Zinc Pressure Leaching Process is based upon the direct pressure leaching of zinc sulphide or lead-zinc bulk sulphide concentrates to produce zinc sulphate in solution and elemental sulphur in the leach residues. The zinc sulphate solution is compatible with conventional purification and electrowinning technology. The pressure leach residues can be treated for the recovery of elemental sulphur, lead and silver. With the conversion of sulphur to the elemental form, zinc pressure leaching allows zinc winning to be independent of sulphuric acid production. Direct pressure leaching of zinc sulphide concentrates was started commercially in October 1980. Continuing research and development studies have defined various pressure leaching configurations for integration with existing roast-leach operations, for grass roots plants, or for plants which are to have the roast-leach section completely replaced. These studies have included the treatment of zinc concentrates from various Australian producers and the development of process flowsheets for potential applications in Australia.

Jan 1, 1989

In general, modern mining companies all over the world have to face the same economic circumstances as any other part of the industry: considering the tough competition, production and haulage costs must be reduced permanently whereas productivity has to increase substantially in order to remain price-competitive. However, the imposed pressure also offers the chance for consideration of alternative mining concepts, the application of which can result in substantial cost savings and improvements in the quality of the mined material. As one of these alternative mining concepts, surface mining technology offers substantial improvements in productivity. It also influences aspects of haulage, such as safety and speed, in a positive way. The capability of selective mining ties in nicely with the production of small-sized crushed material, the granulometry of which allows the elimination of the primary crusher. Mine operators profit from reduced costs for the maintenance of their haulage vehicles due to reduced wear, a decreased likelihood of accidents and higher average transport speeds. Surface Miners can also be used to cut haul roads into virgin rocks and leave a clean and level surface behind, improving the quality of these created roads. Thus, it is even possible to use ordinary road trucks for transport in mines. The current paper outlines in detail the effects of the surface mining technology on mining and haulage aspects and reports on applications where substantial cost savings could be achieved due to the application of what is also referred to as æsimple mining processÆ.

Jan 1, 2003

By Rowley M, Bradford P

Plutonic Resources Limited (formerly known as Pioneer Mineral Exploration Limited) delineated, developed and operates the Plutonic Gold Mine located 180 kms northeast of Meekatharra, Western Australia. Gold mineralisation was discovered in the Marymia greenstone belt by Great Central Mines NL (GCM) in 1988. There was no previous, recorded gold mining activity in the area. In May 1989, Plutonic Resources Limited (PRL) entered into an agreement to acquire a 51 per cent interest in the three Mining Leases containing the Plutonic deposit from GCM. Subsequently in December 1989, PRL acquired the remaining 49 per cent interest in the Mining Leases. PRL and GCM are also involved in a 51:49 regional joint venture on extensive Exploration Licences in the vicinity of the Mining Leases. Following due diligence validation, reserve delineation and testwork, a feasibility study was undertaken in conjunction with JR Engineering Services, which led to the financing and development of the project for operation in August 1990.

Jan 1, 1991

The Fraser Range is composed dominantly of basic pyroxene granulites derived from basalts, many of which appear to have been vesicular and*pillowed. Acidic and basic garnet-bearing granulites are important in the west, and acidic granulites and narrow anortho- site layers are dominant in some regions east of the Fraser Range. An extensive flat-lying olivine gabbro sheet cuts the granulites, and in places has been converted to spinel-bearing meta-gabbros and pyroxene granulites. The granulites of the Fraser Range (Proterozoic) are separated from the gneisses and schists of the Goldfields regions (Archaean) by the Fraser Fault, over which there is a large gravity anomaly (gradient 20 milligals per mile). Some of the problems associated with the concentration of Cu, Ni, etc. liberated from mineral lattices during metamorphism, and other principles of metal concentration in granulite terranes, are discussed. The recognition of vesicular and pillowed zones, even though highly metamorphosed, is of fundamental importance.

Jan 1, 1969

By Martin R. E

L44 Shaft is a major upcast ventilation shalt in the hanging wall of the 1100 Orebody. Various techniques for stripping a raisebored pilot hole were combined to produce L44 shaft. From the surface to 198 m depth, the shaft was concrete lined 7.3 m internal diameter. Below this the shaft was developed to 7.6 m diameter unlined. 11 level, 540 m below the surface, was the first readily accessible level connection. The section to 198 m depth was benched and concrete lined through weak oxidised ground. When more competent ground was encountered the operation was converted to horadiam stripping. This application of the raiseborer has led to a safer, more efficient method of shaft development.

Jan 1, 1977

A simulation model of the load and haul process where the loader cycle has been subdivided into its individual components is used to consider the benefits derived from improved drill and blast methods. Field data from a Hunter Valley mine is u

Jan 1, 1998

By Y-B Kang, J H. Park, J Park

In order to understand the effect of oxygen injection into the molten metal on the valuable metals (VM) recovery and interfacial phenomena, several high-temperature experiments were conducted using a high-frequency induction furnace with a quartz tube as the reaction chamber at 1673 K. Copper-based waste printed circuit board (PCB) that contains some impurities was selected as the end-of-life resource. CaO-SiO2 based pre-fused slag and oxygen gas were used in present works. The composition change and microstructure of the samples were analysed. As oxygen was injected into the system, impurities were rapidly removed. After the removal of impurities, continuously injected oxygen lowered interfacial tension between liquid slag and liquid metal. Lowered interfacial tension induced Cu loss into the slag.

Aug 21, 2024

Experience in evaluating grade control at operating mines has shown that a number of similar errors re-occur in diverse settings. These can be broadly classed as technical errors, and procedural or grade contra management errors. Examples of typical errors are presented a; generalised case studies. A brief explanation of why the recommender solution worked is also presented for each case.

Jan 1, 1993

IN the course of his employment the Broken Hill Co. the writer has had occasion to use and instruct others in the use of the Shamrock rescue apparatus. This paper deals with the various types of apparatus tested. The common object of the various types of breathing apparatus is to enable the wearer to remain and work for varying periods of time in an atmosphere which is either deficient in oxygen or is poisonous that is, contains carbon monoxide or irritating and irrespirable vapours, such as the smoke from underground fires, sulphur dioxide or ammonia fumes. For any apparatus to be efficient as required in the above paragraph it must fulfil the following conditions;1. Air-tight as regards the passage of the air from the outside to the inside. In atmosphere containing carbon dioxide a slight leak would not render the apparatus useless; but where irritating vapours, such as the smoke from burning oregon and sulphides, are met with, even the slightest leak must be avoided.2. The oxygen supply must be ample, and so supplied that it is not checked by expiration.3. Expiration and inspiration must not be retarded.

Jan 1, 1911

By Neto J. A N

Usually there are organisational interfaces between each stage - companies or departments. Each organisation will have different ideas about "optimum" operation. These ideas will be driven by how the performance of each is measured ' and rewarded. Therefore it is important to set up data acquisition processes with respect to maximisation of overall profitability and resource utilisation. In the simplest case - if the miners are paid on tonnes and the concentrator has severe grade penalties on concentrates, then there is the possibility of a conflict of interest over metal Balance.

Jan 1, 1991

By M Matheson

Increasingly, owners and operators of underground mines that have a long history are realising the economic and practical advantages of capturing historic mining records and converting hand drafted plans of underground mine workings into an electronic collection of attributed 3D wireframes that can be used for mine planning and exploration purposes. This case study looks at the conversion of historic data to 3D models, with examples from three historic mining operations where this task has been undertaken: West Wits gold projects in South Africa, Northern MiningÆs Radzimowice gold mine in Poland and Avalon ResourcesÆ Viscaria copper mine in Sweden. West Wits Mining Limited holds leases in the West Rand Goldfield of the Witwatersrand Basin, which has significant gold and uranium resources that have been mined since the 1890s. The Radzimowice Gold mine, Poland, hosts Au-Cu-As-Ag mineralisation that has been exploited since the 15th to 16th centuries. The Viscaria Copper mine is located in northern Sweden and was operational during a 15 year mining period to 1997. The process of data collection, management and modelling is inherently challenging for these mines; specifically, collation of historical information, organising this data into logical arrangements that could be validated and sequentially creating 3D models using geo-spatial computer software. Despite the challenges and costs involved in creating a digital 3D model, the conversion has added significant value to each project through identifying areas of potential new resources, aiding planning and presentation to stakeholders. This paper outlines the processes involved in conversion from paper records to a 3D model, the challenges encountered and how these can be overcome, and importantly, the practical and economic advantages of undertaking such a task for explorers, miners and investors.

Jan 1, 2009

By Gonzalez JM

The Pao gold prospect in N. Luzon, is an example of a high sulphidation epithermal gold system hosted in Mid-Tertiary alkaline volcanics, in the Philippine Arc. Styles of mineralization include: quartz-enargite veins, vuggy silica alteration bodies, and pervasive low grade (0.5ppm) gold mineralization, associated with kaolinite-pyrite-quartz alteration, and geochemically characterized by high As and Hg. Early magnetite-epidote-chlorite alteration linked to an unexposed granitoid is overprinted by an extensive zone of advanced argillic alteration (kaolinite-pyrite-quartz). No alunite is recorded. Important controls of mineralization include; a broad anticline intersected by axial faults, permeable pyroclastic units, and upward confinement of the alteration system by a highly impermeable, clay-rich volcanic unit. At this stratigraphic position the most important mineralization waz developed. The Pao high sulphidation system is not closely related to a stratovolcanic centre, and has formed subsequent to deformation of the volcanic field. It may, however, be related to an unexposed comagmatic intrusion.

Jan 1, 1990

It is difficult with inadvertent explosions to establish fundamental data, especially of original dust, of pressure, temperature etc. and of ventilation oscillations, as exposed personnel rarely survive. Retrospective data from explosions must be derived from damage, from fatalities, from ventilation analyses, from analyses of dusts and other indications of temp- erature and duration of temperature. The five disastrous explosions selected for analysis provide examples of what data can be established as to the cause and extent of explosions. Such information is required for legal etc., inquiries subsequent to explosions, but most importantly to give the best guidance for avoidance of possibility of further Disasters.

Jan 1, 1981