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By S. Ngidi

Palabora Mining Company operates a low grade underground copper mine situated in the Limpopo Province, South Africa. Full production was first reached in May 2005 after a successful transition from an open pit operation to an underground block cave operation. The operation faces a number of technical and operational challenges, not the least being fragmentation of a competent rock mass and external dilution. The cave is subdivided into three main sectors being the east, the west and the central sectors. Caving was initiated from the weaker central sector, which has the majority of its drawpoints located directly under the open pit bottom currently filled with about 130 million tons of waste material from the pit wall failure incurred in 2004. About 48% of the ore reserve has to be extracted from the western sector, which has a much courser fragmentation compared to the other two sectors and only 25% from the central sector with the finest fragmentation. The main constraint during the ramp-up stage has been secondary breaking of drawpoint blockages. Ground-breaking secondary breaking and cave management initiatives and practices have made it possible for Palabora to realize and sustain high production rates.

Jan 1, 2007

The Takasima Coal Mines comprise four islands near the entrance to Nagasaki Harbour, and are owned and worked by the Mitsu Bishi Company.There are several unusual features in the occurrence and working of these coal seams, the steep angle of "dip," the numerous seams of good coal separated by hundreds of feet of sedimentary rocks, the extensive faulting of the strata, and the way in which the coal is won, when so little surface is available for works, and where there is the ever present danger of subsidence of the roof and consequent flooding of the workings by the ocean. The author trusts that short notes on these few points will be of interest to members.The Islands are named respectively Hasima (Extreme Island), Nakanosima (Middle Island), Takasima (High Island), and Yokosima, and are situated about one mile from the main land.

Jan 1, 1901

By R L. Brathwaite

Previous paleodepth studies of low-sulphidation epithermal Au-Ag deposits in the Coromandel region indicated that economic gold mineralisation was generally limited to a depth zone of 100 to 400 m below the paleosurface. Notable exceptions are Waihi and Karangahake, where ore shoots extended to depths of about 750 and 900 m respectively. These studies have been extended to include Au-Ag, Hg and Sb epithermal deposits in Northland and the Taupo Volcanic Zone. The main paleodepth indicators used are sinters and hydrothermal eruption breccias, hydrostatic pressures estimated from homogenisation temperature measurements on fluid inclusions, and hydrothermal alteration mineralogy. Also the occurrence of lacustrine and fluvial sediments is an indicator of the paleosurface at their time of deposition. Selected paleodepth indicators have been compiled and mapped in a GIS environment. The distribution of the paleodepth indicators are used to define regional variations in erosion levels, and may be useful in predicting areas most likely to preserve the optimum depth window for gold deposition. In the Coromandel region, regional stream sediment geochemical data has also been used to broadly define erosion levels in terms of Zn, Pb and Cu representing deeper base metal zone mineralization and Hg and Sb representing shallower cinnabar and stibnite mineralisation. The interpretations of paleodepth and potential reconstruction of paleosurfaces are limited by the paucity of data, poor age control on the paleodepth indicators and the epithermal deposits, and marked relief and complex stratigraphy in the volcanic terranes.

Jan 1, 2003

By B. M. O'Harra

The residues resulting from the retort distillation of zinc ores have from 40 to 75 per cent of the weight of the original ore and contain from 5 to 15 per cent zinc . A rough estimate indicates that approximately 450,000 tons of residues are produced annually in the United States , containing about 36,000 tons of zinc . Besides the current production of residues there are at many smelter sites large accumulations from past operations which are available for treatment if this can be done profitably . In addition to their zinc content the residues contain much unconsumed coal , which has been carbonized during the distillation process , and those from most western ores also contain lead and silver . In this paper is summarized the information obtained in a survey , recently made by the Bureau of Mines , in cooperation with the Missouri School of Mines and Metallurgy , of processes which are in use or which have been suggested for the treatment of retort residues . The complete report of the survey is to be published as a Technical Paper of the Bureau of Mines .

Apr 1, 1923

By Greenwood J. N

This is the fourth paper in the series on Australian w,ar materials and the work was undertaken as part of the programme for producing hard carbides. It had been intended to determine the influence of tantalum and columbium' carbides in mixtures with tungsten carbide. Owing to other, urgent developments, it has not been possible to proceed with that programme.1. THE PROCESSING OF A TANTALITE ORE(a) The OreThe minerals in which tantalum and columbium most commonly occur are tantalite and columbite. These two minerals are the end members of an isomorphous series of tantalates and columbates of iron and manganese, but in nature the series grade into each other.Some of the best deposits of tantalum and columbium ores in the world occur in the north-west of Australia. Until recently tantalite low in columbium was the only mine~al in demand but discoveries of extended uses for columbium, e.g., addition of ferro-columbium to high chromium I steels inhibits intergranular corrosion (weld decay), have created a demand for columbite low in tantalum as weB. Both of these types of' ore occur in the Pilbara district in Western Australia and most of the ore mined is exported to America after a preliminary grinding and concentration by gravity.A sample from the Bynoe Harbour locality, west of Darwin, was used in this investigation. It consisted of coarse lumps of tantalite with quartz in minor amounts. Cassiterite w.as also present. A recent investigation!l) gave the analysis as:

Jan 1, 1943

By Douglas Bartley, Jay Elkin

The state of Pennsylvania was at one time one of the leading coal producing states in the east. However, legislation and industry trends over the last 10 years have adversely affected the amount of bituminous coal mined in Pennsylvania and the whole eastern United States. The application for and approval of a new mining permit is a very costly and arduous task. When a new mining operation is established it is crucial that nothing within the operator’s control causes the operation to stop producing. This paper discusses the action taken by a small mine in Pennsylvania when their blast induced vibrations rose to levels that typically would have resulted in a total mine shut down by the regulatory body governing such operations.

Jan 1, 2003

By R. T. DeWoody, J. W. Chester, W. C. Miller

The work was done to develop a relatively efficient muffler for quieting the exhaust of a rock drill . The exhaust of a pneumatic rock drill is the source of the major part of the noise generated by the drill . The exhaust noise can be reduced in a number of different ways , but this study involved only reactive mufflers . The reactive muffler can be simulated by an electrical circuit . Information obtained from analogous electrical circuits was used to design an efficient exhaust muffler for pneumatic rock drills . Electrical analogies proved to be a valuable tool in the design of mufflers .

Jan 1, 1964

By Kanau JL, Kilgour I

This paper describes the metallurgical processes at the 80 000tpd Ok Tedi Mining Limited concentrator, which treats copper- gold ore by single-stage crushing, SAG and ball milling and flotation to produce over 500 000tpa of concentrate. Plant and process developments, including installation of column cells, reduction of fluorine in concentrate, use of sulphidisation and process control improve- ments are also discussed.

Jan 1, 1991

By A. P. Squelch

The question of what stress condition exists in the hangingwall of tabular stopes remains topical and largely unanswered. Limited field data exist to quantify the situation and provide calibration for investigative computer modelling exercises. Work conducted in1989 and 1990 under a Chamber of Mines Research Organization (now the CSIR: Division of Mining Technology) programme of research into the behaviour and benefits of backfill may assist with this situation. The original work was motivated by the premise that the improved hangingwall stability in backfilled panels (identified by rockfall accident analyses) is due to a change in the hangingwall stress regime. Current, largely theoretical, studies into mechanisms of stope hangingwall behaviour and support interaction could benefit from considering these data. Keywords: Backfill, horizontal stress, stope hangingwall, hangingwall stability, support interaction.

Jan 1, 2002

By Huilan Yang, Feng He

This paper intends to introduce the development of copper smelting and converting technologies in China in recent years, with a particular emphasis on the introduction of various continuous converting technologies, and moreover, it analyzes the advantages and disadvantages of those technologies, including their impact on the downstream anode refining from different points of view. INTRODUCTION At present, many converting technologies are used in copper pyro-metallurgical plants in China, including Peirce-Smith (PS) converter, flash converting furnace, multi-lance based top blowing, bottom blowing and so on. These technologies have spanned a wide range of time. PS converter technology has been applied in copper smelters for many years and most of the blister copper have been produced by this technology; flash converting technology has been developed since 1990s and been maturely applied in several plants up until now; top blowing and bottom blowing technologies have been revived in China in the past decade and boast good environmental protection performance, energy efficiency, throughput capacity and short process flow. All of the said technologies have reference operations in treating high-grade matte. As more and more attention is paid to environmental protection globally and copper smelters continuously seek for cost reduction, it is necessary to share those converting technologies, especially those new converting technologies derived in China, with copper smelting practitioners in the world. This paper aims to analyze the advantages and disadvantages of various technologies from a macroscopic view and discuss their actual application effects, current developments and future improvements. BRIEF INTRODUCTION OF VARIOUS CONVERTING TECHNOLOGIES IN CHINA China has seen a rapid development in copper smelting industry in the past 30 years and has become the largest gathering place of copper smelters in the world, most of which are operating with PS converting furnace technology, however, with the increasingly strict environmental requirements of the Chinese government in recent years, the low-level pollution issue and the disadvantage of large gas exhaust amount per unit of copper of converting furnaces are particularly prominent.

Jan 1, 2019

By S Yuen, T Rana, S Khan

Many open pit mines require dewatering or need aquifer depressurisation systems to manage mine water inflow and/or mine floor stability. In many instances these mining operations impact on regional groundwater resources and therefore access to these resources by other users.As such potential exists for mine development to be hindered or even blocked by groundwater legislation that aims to prevent declining groundwater levels and demonstrate equitable use of a regional groundwater resource.There is a need to manage aquifer systems during and after the mining operations, and in some cases stresses on the aquifers and associated ecosystems may be elastic and can be managed with minimum impacts or reversed once the mine ceases to operate.This paper uses the Gippsland sedimentary basin, with a history of declining groundwater levels and mining and petroleum production, as a case study to pose the question: Should period of mining operation, aquiferÆs storage capacity and its ability to recharge be concurrently considered when granting groundwater abstraction and mining licenses for prospective mine development?It further examines that by utilising an aquiferÆs storage capacity and demonstrating an understanding of aquifer system hydrodynamics during and beyond the life of the mine (time), the approval process for groundwater abstraction and associated cost of statutory monitoring may be made less onerous.

Jan 1, 2009

By A. Monomakhoff

If a conductor traversed by an electric current is broken, a conduction forms in the air between the two broken ends of the wire. This conduction manifests itself in an initial phase by an electric spark and, in a second phase, by an arc if the the circuit continues to supply sufficient power. This arc goes out when the distance between the two ends of the conductor becomes sufficiently large. If the break occurs in an explosive atmosphere, the energy contributed by the arc can cause an explosion. To avoid such accidents, electric circuits that may be utilized in hazardous atmospheres can be made "intrinsically safe". The investigation which we conducted is part of a research project on the intrinsic safety of arcs of high intensity but short duration, in the case of resistive circuits. We developed an electronic system which makes it possible to limit the duration of an arc at the level of the break of a conductor traversed by a current with a possible maximum intensity of 80 amperes. This experimental device for monitoring and measuring the parameters of the arc has shown that arcs of high intensity but with a duration limited to a few microseconds do not ignite an explosive methane-air mixture.

Jan 1, 1975

By P González, E Córdova, E Faundez

An integrated mine system must be capable of displaying and reporting valuable information that can be used to easily understand, manage and take action on the key parameters being reported.One of the key aspects of integration is the standardisation of the mine information up to a level capable of adapting the main characteristics of past projects at the mine and enforcing the same or higher standards for newer projects being developed.At the El Teniente mine, photogrammetry is used to map the advance of horizontal developments, and the constructed 3D representation of each face is then used by the geologists to obtain structural information about the areas being photographed.The mine realised that valuable mining information could also be extracted from the photogrammetry being applied, with three possible areas of development envisioned.The first area was creating a link between the developments being planned on a yearly and monthly basis and matching them with plan sections of the 3D developments of the system to account for any deviations.The second area was to use vertical sections of the 3D developments to estimate the overbreak of the excavations in different areas of the mine.The third area was the provision of a more detailed analysis of the sections so that they could provide information on the thickness of the shotcrete being applied.This paper presents the different alternatives being used and examines how the project is currently being developed and managed at the mine. It also looks at the challenges associated with implementing the reporting platform and the results being obtained.CITATION:Córdova, E, Benado, D, González, P and Faundez, E, 2016. Mine planning information from photogrammetry sources at the El Teniente Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 653–658 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By R. Biss

"Niobium or columbium, as usually called in North America is becoming a more and more important metal in the industrial world because of its attractive properties.Eventhough discovered in the early nineteenth century, it was not until the 1930's that its use became more widespread. The discovery of large commercial deposits in the late 1950's and the demand of industry for steel with high strength and toughness further promoted its use. To assure its adequate supply new or-e processinr technologies had to be developed. So, beside the traditional gravity concentration, the flotation process was employed for the partial upgrading of pyrochlore concentrate at S8ve (Norway) plant in 1953. The flotation process was equally used at St-Lawrence Columbium plant in the province of Quebec, Canada. The new plants at Araxa and Catalao in Brazil and at St-Honore, Canada, which supply almost of all niobium used today in the non-Communist world, also adopted the flotation process. The processes using long chain aliphatic rnonoarnines, diamines or sulfonates as collectors proved to be difficult especially on weathered types of ores or on those having a substantial content of silicate gangue minerals. They almost completely failed in case of alkaline intrusive rocks as syenites, nepheline syenite, ijolites and pyroxenites, composed almost entirely of silicate minerals. A lot of effort was devoted all around the world on research of new, more efficient flotation processes. So in 1982, Les Services T.M.G. Inc. (Niobec), sole producer of pyrochlore concentrate in North America, developed the direct pyrochlore flotation process from carbonatites. In 1983, at about the same time, the Quebec Department of Natural Resources Laboratories and Les Services T.M.G. Inc. announced a successful recovery of niobium Minera1s from a low grade nenheline syenite ore."

Jan 1, 1984

By Yajie Wang

Traditionally, roof falls are usually attributed to bad roof strata and high vertical stress related to the overburden depth. However, roof falls under shallow overburden depth are oflen caused by a high horizontal stress field. Recent studies have proven that the high horizontal stress field, if existing, plays a major role in roof stability. Also the roof conditions are related to the entry diredions under a horizontal stress field. Questions are: How to orient the entry to a favorable direction to prevent the roof falls? If the entry cannot be oriented, how to support it? Through a case study in mine A, this paper analyzes the horizontal stress effect on roof stability. The guideline for the entry orientation is given based on the results of analysis. Additionally, suggestions are made for those entries that cannot be oriented to a favorable direction.

Jan 1, 1998

By A. B. Desai

The construction of 1144 nos. of piles, each 1.5 m diameter, bored-cast-in-situ type and varying in depths from 6.5 to 23m, has been completed as foundation for 26 piers of 548 m long aqueduct across Orsang river to carry 1128 m3 water of Narmada Main Canal of the Sardar Sarovar Project in Gujarat. These piles are socketed 1.5 m into foundation grade rockmass. The portal system of 44 nos. of piles and pile cap at the top for each pier is analyzed considering the portal fixed at bottom of piles. The borings for pile shaft were done deploying reverse mud circulation rigs and also by conventional chiseling and bailing operations. Besides vertical loading tests and lateral loading test on piles, dynamic tests such as low strain integrity testing on 290 piles and high strain pile testing on 17 piles were also conducted. The results indicated that (a) the settlement/ displacement are much less than the prescribed limits (b) good quality of concrete (c) piles are firmly socketed and (d) piles have adequate structural capacity to withstand the design load.

Jan 1, 1996

The MineSight Schedule Optimizer (MSSO) is a new production scheduling tool developed by Mintec, Inc. using mixed integer linear programming (MILP) techniques. This tool was developed to solve the short- and medium-term schedule problems for surface and underground mining operations that involve multiple mining areas, multiple processes, multiple destinations and blending requirements. MSSO finds the optimum schedule in each period that achieves the objective while satisfying comprehensive product quality and quantity requirements as well as physical and technical constraints. Using the MineSight Planning Database (MSPD) as a central data hub, MSSO seamlessly works with MineSight 3-D (MS3D) block models and third-party data, MineSight Interactive Planner (MSIP), MineSight Haulage (MSHaulage) and MineSight Activity Planner (MSAP) to prepare data, formulate MILP models, calculate, report, fine-tune, save and visualize schedules. This paper presents the features and capabilities of MSSO. A case study is also given to demonstrate the applications of this new tool.

Jan 1, 2009

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimina- tion of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To deter- mine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with refer- ence to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope. Although the hypothesis as to coking quality finds but partial support in the chemical analyses, its consideration has led to a method of predicting from an analysis with a fair degree of certainty whether any given coal will coke by the ordinary process. The unbroken transition between coals originally similar but now classed in widely different groups, whether of the same age or of different ages, as a result of dynamochemical action, appears demonstrated by the analyses as well as by field observation. This subject will not be

Jan 1, 1911

By A. P. Squelch

The high incidence of accidents and fatalities in the South African mining industry, in particular those associated with falls of ground, is often attributed to ineffective and/or inappropriate training methods and material. Recently introduced mine health and safety legislation in South Africa also requires that all mine workers receive appropriate and effective training to enable them to operate safely in their given mining environment. There can, therefore, be no doubt that methods to provide effective training, in particular safety related training, are urgently required in the South African mining industry. In the search for alternative and improved training approaches, attention has fallen on virtual reality (VR) technology as a possible solution. VR has found acceptance in a number of industries as an effective method of training for a variety of work place activities, including those of a safety related nature. VR has successfully been applied in a number of industries to improve the effectiveness of safety and hazard awareness training. The CSIR: Division of Mining Technology (CSIR Miningtek), in conjunction with the Safety in Mines Research Advisory Committee (SIMRAC), therefore evaluated the potential of VR to be used as a training medium in the South African gold and platinum mining industry. Aspects of the evaluation included an assessment of the technical capability of VR to represent a typical underground mining environment with sufficient realism and the relevance of the VR training concept for a largely illiterate workforce. For these purposes, a prototype PC-based VR hazard awareness training simulator has been developed by CSIR Miningtek, and a series of evaluation sessions conducted at a typical deep level gold mine. The conclusion from this evaluation work is that virtual reality technology has the potential to provide effective training systems that are relevant to the South African mining industry. Keywords: Virtual reality, mine training, safety training.

Jan 1, 2001

By Allan Sylvester

This paper will discuss the design, construction, and performance of the support of excavation on the San Diego State University LRT Station. The vertical elements of the system include drilled secant piles and drilled soldier piles. We will discuss the geo-technical characteristics, design and construction considerations, loading criteria, construction techniques, schedule constraints, and performance of the pile and support of excavation systems. In consideration of the conference theme, there will be a discussion of the successful accomplishment of meeting the interim milestone dates of the Contract. The project team cooperatively worked to design and install approximately 1,100 drilled secant and soldier piles as well as excavate and install the balance of the support of excavation elements in such a manner as to minimize the disruption to campus students and operations.

Jan 1, 2002