Search Documents

By M E. Pierce

Recent advances in comminution and heap leach technology have resulted in the development of many large-scale, low-grade open pit mines that coincide with areas of historical underground workings. Twoand three-dimensional numerical modelling has been conducted to assess the interaction between open pit slope stability and remnant underground voids. Most design analyses for open pit slopes assume a two-dimensional problem geometry. This is not the condition encountered in practice ù particularly when remnant underground voids interact with a large-scale open pit slope. Three-dimensional numerical models have been shown to provide a more realistic representation of the interaction between overall open pit slope stability and remnant underground voids.

Jan 1, 2003

By Campbell D. L, Nutt C. J

The Delta two-degree quadrangle is located in west-central Utah, in the eastern Basin and Range physiographic province but near the intersection of the Basin and Range, Rocky Mountain, and Colorado Plateau provinces (Fig. 1). The quadrangle lies in the region of interior drainage that includes western Utah and most of Nevada, and, like the rest of that province, it has an arid climate. This work is part of the United States Geological Survey's ongoing CUSMAP (Conterminous United States Mineral Assessment Program) project in the Delta quadrangle. Trace-element geochemical data presented here includes information from approximately 600 heavy- mineral-concentrate and 2500 rock sample sites from throughout the Delta quadrangle.

Jan 1, 1988

By Corbett G, Iwai N

The Japanese gold mining industry has a long and productive history and is presently undergoing a period of revitalisation encouraged by the Hishikari discovery. Deposits exhibiting the characteristics of epithermal mineralisation are very widely distributed throughout the island chain and an encouraging number of these are large, seven containing gold in excess of one million ounces. All the important deposits are quartz vein type and contain extremely high grade, or "bonanza". Zones.

Jan 1, 1990

By Bin H

East Guangdong tin province overlaps the southmost part of the mesozoic magmatic arcof continental margin type in Southeast China and is dominated by mesozoic syntectic magmatism,which associated to tin mineralization. It is distinguished from Nanling tin province but quite close to NW Bolivian tin province in both tectonic and magmatic relations.Tin deposit's mostly of cassiterite-sulfide, cassiterite-silicate formations are localized along exsocontact zone of granitoid batholith or stock, boundary area of volcanic depression, or, within volcanic edifice. Petrochemistry studies show tin was concentrated as intermediate-acidic magma evolved by fractional crystallization. Xiling tin deposit of vein type related to extrusive... the lava dome was formed at T C 221-301 and at very shellow depth,seems to correspond to type A in classification for Bolivia tin deposits by J.N.Grant. Tashan tin deposit of dissemination type related to hypergene intrusive facies,with mineralization occured in endocontact zone of granite porphyry dykes is considered as porphyry type,which spported by H-0 isotope and gas-liquid inclusion evidences. It formed at T C 250-430, comparable to Bolivia porphyry tin deposits,but at a greater depth 1.3 3.0km.A model for known tin deposits in East Guangdong was worked out. A good prospecting perspective was revealed for the potential type of tin deposit in East Guangdong--subvolcanic porphyry tin deposit.

Jan 1, 1990

By A Boeing

Rock-breaker automation and remote operation improves the safety and efficiency of mining operations. This paper presents an overview of the Rocklogic rock-breaker automation system architecture that provides collision avoidance, automated parking and remote operation functionality. The system consists of a distributed computer control system that interfaces with sensors attached to the rock-breaker, the rock-breaker hydraulics and the site infrastructure. We present results of an automated Transmin rock-breaker installed in a production environment at an underground Australian mine site. The system has been in production use for over 900 days, during which there have been no reported collisions and 100 per cent adoption of the remote operation technology. As a result, Rocklogic has significantly improved the safety of rock-breaking operations and reduced the rock-breaking cycle time, thereby improving the site’s overall throughput.CITATION:Boeing, A and Douglas, E, 2014. A remotely operated robotic rock-breaker with collision avoidance for the mining industry, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 131–136 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

Lake Kopiago is located some 71km northwest of Tari in the Southern Highlands Province and lies on the northern edge of the Papuan Fold Belt. The area is underlain by middle Miocene carbonate and fine grained clastic sediments intruded by late Miocene hornblende gabbros.Two mineral deposits occur to the south of Lake Kopiago. These are the Bisamu gold prospect and the Wunaki zinc-lead gossan.The Bisamu deposit consists of a calcic skarn assemblage which is geochemically anomalous in gold, silver, copper, zinc, cobalt, bismuth and tellurium. The prograde mineral assemblage includes garnet, clino-pyroxene and epidote whereas the retrograde assemblage includes epidote, quartz, actinolite and chlorite. Pyrrhotite is the dominant sulphide with minor pyrite and marcasite and trace chalcopyrite and sphalerite. Minor magnetite is also present. The Bisamu skarn shows many of the features typical of gold-skarn type mineral-isation.

Jan 1, 1994

By Worotnicki G, Tillmann V. H

Past experience with fully bonded cable dowels placed as a means of reinforcement in highly stressed crop pillars at the New Broken Hill Consolidated Limited (NBHC) mine indicated such support was not fully effective. Typically overbreak of the crown occurred leaving long lengths of cables hanging from the back stripped of grout and rock with the potential load carrying capacity of the cables not having been fully utilised. This mode of behaviour had been observed in the cable dowelled crowns of three longhole open stopes (EROS) mined to the No. 12 level at NBHC. A system of support with improved mechanism of load transfer from rock to cable and capable of full utilisation of cable strength was proposed for the crown pillars of future Stopes.

Jan 1, 1983

By Griffiths J. B

From its mining lease at the northern end of Cohens Reef at Walhalla in the North Gippsland Mountains, the Long Tunnel Extended Gold Mining Company produced 13,695 kg of gold, which at 1980 prices represents a value significantly in excess of $200 million. In the period 1885 to 1908 the mine was one of Australia's principal reef gold producers, being top Victorian producer in six of these twenty-four years. Prior and subsequent occupants of the lease produced an additional 160 kg of gold. The Extended and the other mines on Cohens Reef whilst contributing importantly to the financial resource of Victoria, were the sole important support for the substantial town of Walhalla that had grown up around them. When the mines closed, Walhalla gradually reduced from a bustling developed town to the present attractive mountain village so favoured by tuurriSts. To allow the visitor to obtain a better ;ri.icrstanding of Walhalla's mining past, important parts of the Long Tunnel Extended Gold Mine workings and site are being

Jan 1, 1981

This paper examines the various stages of development and design work which were necessary to develop the cemented rock fill system for copper mining at Mount Isa. The reason for a cemented sand fill development program together with details of the test work undertaken are briefly outlined. The testwork associated with the selection of a suitable local rock to supple- ment the cemented hydraulic fill is discussed, as is the method for underground placement and mixing of the graded rock with the cemented hydraulic fill. The design features of the final system which incorporates a graded rock handling system and a cemented hydraulic fill reticula- tion system is outlined.

Jan 1, 1973

By Daziel M, Corke P

Unit cycles in mining have not changed for many years. Productivity increases over the past three decades have mainly been achieved by using larger and heavier machines. This investment in size has probably reached the point of diminishing returns and increased productivity in the future will have to be generated by other means. One way of achieving this is through automation of selected unit operations, eg dragline overburden removal, truck haulage, ground support installation and secondary breakage. Although, in the past few years, there has been significant progress in this direction, we are still a long way away from even partial automation - especially in hard rock mines. This paper addresses the technical obstacles facing mining automation; suggests ways by which these obstacles may be overcome and identifies the role of industry groups and research providers in this process.

Jan 1, 1997

By Hayward P. G

Complex ores, characterised by intimate intergrowths between minerals, have previously been treated by flotation with limited success. The most common problem has been that the liberation size is often finer than the lower size limit for selection flotation. A technique has been developed in which the problem is overcome by the use of a selective agglomeration procedure in which the values are coalesced with oil to a size suitable for flotation prior to introduction into the flotation machine. A complex lead ore was characterised by QEM*SEM mineralogy as having a mean galena liberation size of 15 ¦m. The best recovery of lead at 50 per cent Pb grade by standard flotation was 53 per cent. After application of the procedure, 86 per cent recovery was obtained after a single cleaner step. The oil functions as a bridging liquid in the presence of conventional collectors which render the mineral oleophillic.

Jan 1, 1991

By Jiang G

The Chinese Central Government attaches great importance to the development of its coal industry. Besides carrying out the policy of simultaneous development of large, medium and small coalmines,the main strategy is to gradually modernize coal mining areas and coalmines and to increase the output from individual coalfaces. There are particular implications, processes and main experiences of coalmine modernisation in China.Ensuring a coal output of over one M tonne/yr from one coalface is a very complicated system-engineering project which deals with a wide range of problems. The most important measure used for achieving an output of over one M tonne/yr from a single coalface is the analysis of affecting factors on coalface production by means of the theory c reliability. Thus, as far as possible , the production stoppages caused by mechanical equipment failures and other factors are avoided, the equipment recovery rate is increased and the working hours of shearers are extended so as to ensure a high output and high efficiency.

Jan 1, 1991

By M Ljunggren, M Lundh

Dissolved air flotation (DAF) in wastewater treatment as a separation process of submillimetre biological flocs is based on the generation of bubble/floc aggregates. DAF is a complex process but has got advantages, such as allowing a high hydraulic load, compared to sedimentation. A thorough knowledge of the physics of the DAF process is, however, still lacking. This paper will present results of experimental studies on three aspects of significance to the separation process û the flow structure in the flotation tank, rise velocities of aggregates, influence of floc size on the separation efficiency. Flow structure. Measurements were performed in a pilot plant mapping and visualising the velocity field. The dispersion water (bubbles) had a decisive influence on the flow structure due to the effect of the bubbles on the bulk water density. Stratified conditions with a less dense, bubble-containing upper layer and a clear water, denser bottom layer were important for a good separation. A simple model of the stratified flow structure was elaborated making it possible to interpret the function of the aggregate rise velocities. Bubble/floc aggregates. The dynamics of single flocs, bubbles, aggregates were visualised using a borescope + CCD video camera + digital recorder + image analysis. Sequences of video frames made it possible to determine the rise velocities of the single aggregates. These velocities were found to be in the range 1 - 9 mm/s with a tendency for large flocs to have higher rise velocities. Separation versus floc size. The floc size distribution was measured in the DAF process. Data from three different DAF cases showed, that large flocs (> about 100 ¦m) were entirely separated, whereas small flocs experienced a less good separation. It was, moreover, found, that a very significant separation of flocs took place in the very upstream end of the separation zone in a pilot plant case.

Jan 1, 2005

CONTENTSSummaryIntroductionGeographical and Geological Outline of the RegionGrowth of the Mining IndustryTable 1: Production StatisticsGeneral GeologyRecent Alluvium and River GravelsSambeto SeriesMudstone and Basalt ContactVatukoula SeriesIntrusivesStructureGeologic HistoryLodesTable 2: Principal Lodes and Their OrebodiesMineral Assemblage and ParagenesisOre Shoots and Their ControlEmperor MineLoloma MineDolphin MineExplorationConclusionAcknowledgmentReferencesSUMMARYThe Tavua Goldfield was found in 1932 within a basin, both topographical and structural, near the sea on the north side of Viti Levu, Fiji, and has produced over £13,000,000 (Fijian) worth of gold and silver from the three mines...

Jan 1, 1953

By J J. Cilliers, K Hadler, A W. Stra

This paper examines the use of the FrothSim flotation simulator to improve the performance of an industrial column flotation cell. The performance of an industrial retreat column cell is simulated, and, from the discrepancies between the simulated and experimental results, a problem with the wash water distribution is postulated. The scientific reason for the reduced performance with uneven wash water addition is described in detail. Further simulations indicated the potential for improvement with an even wash water distribution, resulting in both improved performance and reduced wash water usage. The simulated uneven wash water distribution was confirmed industrially, and the headers were redesigned and installed. A sampling campaign to compare the performance before and after the modifications showed that the flotation performance was improved dramatically, with a statistically significant decrease in gangue recovery, without a commensurate reduction in valuable mineral recovery.

Jan 1, 2005

By Fabjanczyk MW, Nemcik JA, Matthews SM

The major strata control considerations which affect the optimisation of roadway driveage in highly stressed strata is the performance of reinforcement placed and the extent of stress induced rock deformation. High development rates and opening stability requires efficient rock reinforcement and stress relief strategies which maximise the integrity of the rock about roadways created. Current studies demonstrate the capability to reduce lateral stress distributions across panels and research is aimed toward a higher capacity bolting system. It is the intention to provide industry with more efficient reinforcement and stress control alternatives which will allow high production development equipment to operate without the restriction of delays caused by poor ground Conditions.

Jan 1, 1988

By Rongqing Q, Tiancong Z, Yiyuan L

The influence of pulp density, ferric ion concentration and particle size on the tank bioleaching of two kinds of refractory gold concentrates are discussed. The chemistry and mechanism of the bioleaching process are also presented. The relationship between oxidation of sulphides, liberation of enclosed gold and gold cyanidation are discussed. The consumption of NaCN could be reduced by alkaline treatment of bioleached residues prior to Cyanidation.

Jan 1, 1992

Viking Holdings Ltd, a Todd Corporation company, is active in the mineral industry through operations, joint ventures and equity investments. Identification and management of risk is key to the success of the company. This paper discusses risk in general terms and in the context of Vikings activities. Reference is made to the current environment and the impact of risk and environment on profitability.

Jan 1, 1997

A short overview of the research program of SveBeFo, Swedish Rock Engineering Research, which was founded in 1993 is first given. Then four recent and ongoing projects in rock blasting and explosives engineering are presented in greater detail: 1. Burn Equations for Commercial Explosives. 2. Blast Damage in Contour Blasting. 3. The Role of Gas Pressure in Pit Wall Damage. 4. Fragmentation of Aggregate Rock. The goal of the bum equation project is to be able to control the energy release from explosive charges to the desired part of the expansion curve of the reaction products under various rock conditions. SveBeFo's work has reached the stage where a burn equation for a lab emulsion has been established which can model the influence of charge diameter on the VOD and detonation front curvature in a cylindrical charge quite well. This work now continues with other emulsion recipes. In the blast damage project the goal is to develop techniques and recommendations on how to minimise the blast damage in construction blasting. The project has gained extensive practical knowledge from the blasting of more than 200 holes in a granite quarry under controlled conditions. The cracks in the rock surrounding the contour holes have been cut open and measured. The influence of factors like charge concentration, decoupling ratio, hole and charge size, VOD and time delay in initiation have been investigated. A simultaneous initiation of a group of contour holes with EDD detonators is quite superior to single hole blasts, even when they are timed as closely as 1 ms.

Jan 1, 1995

By Nolan D. P, Balales M

Over the last two years work has been undertaken within the Pasminco Metals - BHAS Zinc Plant to improve the efficiency and maintain the production capacity of the operation. The work has centred upon the installation of suitable process instrumentation to improve process control and the development of new unit operations to maintain control of the circuit water and sulphate balance. A key aspect of the new process instrumentation has been the development of an on-line analyser to monitor the total antimony concentration during zinc dust purification. As a result of changes made to the Zinc Plant in order to contain all effluent within the circuit, a problem developed with control of both the water and sulphate balance of the circuit. A new neutralisation plant to treat all cell house waste water so that it can be contained within the circuit has been developed and installed. In addition changes have been made to the existing circuit to control deliberately the circuit sulphate concentration by precipitation of sodium and potassium jarosite.

Jan 1, 1993