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By Madgwick J. C

A novel, microaerobic, heterotrophic microbial leaching system for manganese dioxide is described. Mixed natural microflora were enriched by addition of sugars and crude plant nutrItIOnal supplements. Between 84 and 104 mg MnH was solubilized per gram sugar at I per cent (w/v) concentrations for fructose and galactose in the presence of 0.03 per cent w/v dried microalgae (a Chlamydomonas species). Some 42 per cent soluble manganese was dissolved by microbial action on MnO, (3 per cent (w/v) pulp density) using a 10 per cent (w/v) molasses growth substrate.

Jan 1, 1983

Coal cleat and faulting influence failure, gas release, and choice of preferred mining directions, locations, and sequences. Unfortunately soil and younger rock cover restrict direct mapping of these structures ahead of mining operations. Aerial photographs of cover contain indirect indications of concealed structures in arrays of linear photostructures. These arrays are commonly too complex for interpretation by simple visual inspection.Analytical techniques applicable to complex arrays are illustrated for a covered part of the Galilee Coal Basin, Queensland. These techniques are: optical determination of sets in arrays of photostructures; correlation of these sets with sub-surface structures; filtering of m-rays for particular sets; detection of anomalies associated with concealed structures in the density distributions of particular sets; fitting filtered arrays to trajectories; correlation of trajectories with the regional directional variations of concealed structures; contouring of ratios of sets to discriminate anomalies associated with concealed fractures and variations in the total and bed thicknesses of cover; kinematic and dynamic inference on the basis of fracture-trace angular and spatial relationships.

Jan 1, 1979

By Y. van der Grijp

The applicability of a stochastic approach to the simulation of gold distribution to assess the uncertainty of the associated mineralization is examined. A practical workflow for similar problems is proposed. Two different techniques are explored in this research: a Direct Sampling multi-point simulation algorithm is used for generating realizations of lithologies hosting the gold mineralization, and sequential Gaussian simulation is applied to generate multiple realizations of gold distributions within the host lithologies. A range of parameters in the Direct Sampling algorithm is investigated to arrive at good reproducibility of the patterns found in the training image. These findings are aimed at assisting in the choice of appropriate parameters when undertaking the simulation step. The resulting realizations are analysed in order to assess the combined uncertainty associated with the lithology and gold mineralization.

Jan 1, 2015

By Creasey J. W, Huntington J. F

Faults cutting the Lithgow and Katoomba seams in some collieries of the Western Coalfield can be classified, on the basis of spatial pattern, into three principal groups: meridional swarms of closely spaced minor faults and associated joints, with throws of less than 0.5 m and with exceptional faults of up to 5 m; isolated interswarm strike-slip faults in the Lithgow seam and widely spaced strike-slip faults in swarms in the Katoomba seam; and low-angle normal faults associated with the Lidsdale-Lithgow seam split.Orientations of faults and coal cleats in the coalfield are presented on stereoplots and histograms, as a basis for an analysis of fault dynamics. The low-angle normal faults were found to have been formed only along the Lidsdale-Lithgow seam split, and before the high-angle faults. The origin of the high-angle normal faults in the meridional swarms is discussed and it is suggested that basementcover interactions must have occurred. This suggestion is supported by geophysical evidence. Low-amplitude monoclines in the coal seam, and the spacing of swarms 0.9 to 4.5 km apart, may be due to the underlying basement structure.It is clear that postextensional compressive deformation of swarms in the coalfield gave rise to shortening by minor thrust development, and probably also caused the synchronous strike-slip movement on pre-existing normal faults. There is evidence to show that isolated interswarm strike-slip faults in the Lithgow seam, and widely spaced strike-slip faults in the Katoomba seam, may have originated synchronously with such thrusts. The axis of maximum principal compression ('71) for the thrust event was inferred to be near horizontal and aligned approximately E-W. Recent rock mechanics measurements of the present day stress field indicate a similar stress configuration.

Jan 1, 1981

Copper, zinc, lead, and silver in the discordant magmatic-hydrothermal orebody of the Conrad Mine, N.S.W., all have a relatively high mean abundance. Any single concordant sulphide orebody containing the same metals has a similar order of mean abundance of only one or two of these, particularly copper, copper and zinc, or zinc and lead.The relative abundances of the metals in the Conrad orebody vary more widely than in concordant orebodies, and the lead-zinc-silver and copper-zinc-lead relationships are significantly different.INTRODUCTIONIn previous investigations of metal abundances in sulphide ores, the basis of selection of the orebodies was their form, and to some extent their geological setting, rather than hypotheses concerning their origin. In all cases they were generally concordant with the bedding of the sedimentary or meta-sedimentary rocks enclosing them, and most occurred in volcanic-sedimentary sequences. Their mineralogies were simple, and they were copper, copper-zinc, zinc or lead-zinc rich in composition. Most were of the type ascribed by several authors to exhalative-sedimentary processes.In one of these investigations (Stanton, 1958), it was pointed out that since the metals in ores of this type showed similar abundance patterns and behaviour, it would clearly be of interest to examine, and to compare with them, orthomagmatic and vein types, unquestionably derived from their igneous rock associates.The present investigation is concerned with a single orebody, of clearly discordant type, and of indisputable hydrothermal origin. The abundance and behaviour of copper, zinc, lead, and silver have been determined and compared to similar data fOl!' the concordant type. Such a comparison tests the possibility that metal abundance patterns of base metal ores may be indicative of the mode of ore deposition.

Jan 1, 1963

By Paul Hatmaker

"The Bureau of Mines recently has issued a general information circular covering briefly the origin and occurrence, properties, uses, exploitation, and marketing of diatomite. Since this publication was prepared, additional information has become available regarding one of the newer uses of diatomite — that as a filler in battery boxes. As this market is rapidly becoming one of the important outlets, a brief discussion of such use may be of interest.Diatomite is a mineral substance composed principally of the skeletal remains of diatoms. The skeletons of these microscopic flowerless water plants are made from silica present in the water in which these tiny plants live. The minute shells or ""casts"" accumu¬late in the bottom of lakes, ponds, or inland seas, and eventually become more or less consolidated into beds of diatomite.The uses of diatomite depend largely upon its peculiar properties. Diatomite is a highly porous substance and possesses marked absorptive powers. The large percentage of pore space makes the material very light in weight. It is relatively insoluble in most solutions.The largest deposits in the world are found in California, but diatomite occurs in many other Western States and also is found in a number of places along the Atlantic seaboard. Outside of the United States diatomite occurs in many countries; Algeria and Germany are among the largest producers.Usually diatomite is mined either by underground or open—cut methods. In some instances it may be dredged from lake and swamp bottoms. It must be dried prior to grinding or other preparation for market, and for many purposes must undergo a complex sizing and grading system for removal of such impurities as sand and clay and for classification of the material to the various sizes desired,"

Mar 1, 1931

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 John D. Godfrey

Geological mapping on the Canadian Shield in northeastern Alberta outlined severalgranitoid rock massespotentially suitable as building stone. A particularly attractive prospect, the Chipewyan Red Granite, was subjected to an aerial survey and ground check. The petrologic and fracture characteristics critical for quarrying and use as a building stone were assessed in the course of detailed mapping at two of the most favourable sites. The extension of good rock was tested to shallow depths at one site by shallow diamond-drill coring. , The Chipewyan Red Granite displays a warm red colour, medium grain size and fairly massive texture, and takes a good polish. Deleterious geologic features studied in outcrop and subjected to structural analysis included regular joint systems, quartz veins, pegmatite dykes, basic shear zones and fault zones. Many of these key geologic features are systematic and hence predictable for stone quarrying purposes; other features, such as irregular fracelM tures, are non-systematic and arefar less predictable. The megascopic structural features studied show similar preferred orientations which appear to be collectively related to the tectonic history.

Jan 1, 1979

By M. F. Trice

PYROPHYLLITE is a hydrous aluminum silicate (A12Si4010(OH)2)1 that occurs in both the foliated and the massive forms. The foliated variety resembles talc in that it has a greasy feel, a pearly luster, perfect basal cleavage, and usually is white, although in some deposits apple green, gray, brown, russet, and nearly black specimens may be found. The massive deposits of pyrophyllite yield pearl gray to light tan aggregates, some of which are so friable that they may be crushed with the hands into a fine gritty powder. Frequently specimens of the massive variety are studded with crystals of radial structure. The mineral has a specific gravity of about 2.7 and a hardness of 1 on Mobs' scale.1 The chemical composition of commercial pyrophyllite reflects the mineralogy of the deposits, which, according to Stuckey,2 contain pyro-phyllite and quartz, together with chloritoid, sericite, and a few other minerals of negligible importance. The latter, he says, "are noticed in but small quantities to the extent they might occur as accessory constitu-ents of an igneous rock or as products of regional metamorphism or weathering. . . . Quartz is abundant everywhere except in the very best grades of pyrophyllite." Analyses of specimens from several deposits are listed in Table 1, showing that the silica content varies from 57 to 73 percent and the alumina from 22 to 33 percent. Oxides of iron and the alkaline metals are collectively present, with one exception, to an extent of about 1 to 1.5 per cent.

Jan 1, 1940

By L. du Plessis

The name FISH (Fully Integrated Sort House) refers to a class of technology deployed at Jwaneng Mine final diamond recovery. The FISH concept is based on three pillars, namely: ?Improved sorting efficiency FISH is based on laser technology, which is more efficient than hand sorting for certain product categories. Laser sorting is based on measuring in-elastically scattered light from molecules and this is referred to as Raman spectroscopy. The Raman scattered light occurs at wavelengths that are shifted from the incident light by the energies of molecular vibrations ?Availability of production information Roller gap diamond size distribution information is generated on line for upstream process optimization ?Improved product security A ?hands-off? philosophy reduces security risk during operation and maintenance of the plant. In addition, a number of lessons were learnt about the application of new technologies in the industry: ?The required human competency profile demanded by new technology should match the available competencies of the operational staff ?An integrated information management system should be fully functional for both production management and diamond control purposes ?Operational feedback must be correctly evaluated to identify design, maintenance, training and operational issues so as to accelerate the maturity of the new technology within the time span of the sustainable operations project ?Project execution and technology maturity risks have to be evaluated and married to ensure risk mitigation by means of suitable project resource and contracting model selection.

Jan 1, 2003

By William Babcock

Augered, Cast-In-Place (ACIP) piles can be an economical, reliable, versatile foundation system. They have also been a part of projects that were behind schedule and the subject of lawsuits. The ACIP pile is a specialty system that is more workmanship dependent than most deep foundation systems and is especially vulnerable to the problems and abuse of poor specifications and contract language. Many of the original specifications were based on grouting methods, and numerous misconceptions have followed the method. The Deep Foundations Institute (DFI) has been the leader in debunking the mystique that has hovered over the method and attempted to standardize the industry through publication of the manuals describing the method and how it should be inspected. DFI should be applauded for taking the lead and producing a reference document that can be used to educate the specification writers, designers, inspectors, and owners. It must be must appreciated that there have been other organizations that would not acknowledge ACIP piles as a legitimate member of the deep foundation family. Some consultants and designers have gone to the extreme of making it policy to not recommend the method for use. This presentation is one practitioner's view of the causes of problems as they can be traced back to the contractual conditions. It is intended to provide a broader and different perspective than those provided by the technical specialists. It does not necessarily reflect the position of the DFI or any of the organizations associated with the ACIP pile industry. It is intended to further the spirit of partnering on every ACIP pile project, to further the acceptance and promote the use of this unique system, for the benefit of all the parties. It should be recognized, however, that all of the participants can and do play a role in getting a project into trouble. My view is that projects that get into trouble usually have an early flaw that leads the project to the edge, and the project participants blindly follow the original mistake right over the cliff like lemmings. This instinctive reaction may be a survival tactic by going along with the group, because any one party that departs from the program or shows a position of weakness is a candidate for sacrifice.

Jan 1, 1997

By C. M. Rule

Energy efficiency is currently a significant area of interest due to the Eskom power situation, which led to severe power impacts to the PGM, and indeed whole SA primary industries, in early 2008. Anglo Platinum has focused on energy efficiency for a number of years, especially in the concentrator operational area. New comminution technologies have been aggressively developed, which have shown real metallurgical efficiency gains as well as significant energy efficiency and saving potential for Anglo Platinum?s total electrical consumption as the company expands into a growing PGM demand market. This paper illustrates this programme?s activities, potential and considerable achievements to date.

Jan 1, 2009

By Feng Yongxuan

Anchored sheep pile is normally used in deep excavations, many of which only require stability in accordance with Terzaghi theory. In this paper, based on the experience, new lateral earth pressure method is adopted taking account into interaction among soil, anchors and sheet piles so that a group for the project under very difficult conditions and very severe requirments, especially, for the displacements are determined according to that mentioned above. During and after construction, displacements monitoring were carried out for about four months, which was proved that there was a little difference between calculation and practice.

Jan 1, 1991

By P. K. Guerrero, N. Arbiter

The correlation of power consumed by a tumbling mill with the dimensions, speed, and load has been attempted by three principal methods. One of these, the torque formula, has been reviewed critically elsewhere.' This approach, while analytical, disregards the individual motion and speed of the tumbling bodies and assumes that the gross geometry of the entire load is sufficient to establish the power requirement. A more general approach, using dimensional analysis, has been applied in this laboratory by the present authors1'1, and more recently by Rose.3 This disregards the internal conditions within the mill entirely and in effect is an empirical procedure for correlating data. Finally, the complete analysis of tumbling mill dynamics as first made by Davis' attempts to develop the power requirement from individual ball and rod paths and velocities. Although Davis' result is applicable only at a single speed for a given size and load it could be useful, since his optimum speed is at the upper limits of conventional tumbling mill practice. Where power values predicted by the Davis equation were compared with actual mill requirements, they were found too low for small mills and much too high for the largest mills. This suggested that the agreement with actual intermediate range requirements might be fortuitous, and the development of the equation was examined critically. The probable source of error was found to lie in an erroneous assumption made by Davis in converting the energy of ball or rod motion to power. With the same approach, but with different assumptions, a modified equation has been obtained which predicts results that are usually consistently high. This is to be expected, since it is assumed that there is no slip between load and shell and no interference among tumbling bodies. Both these effects should account for the difference. Development of Equation: When a cylindrical shell charged with a substantial weight of rods or balls is slowly rotated about a horizontal axis, the load surface first assumes an inclination that gradually increases to a maximum. Continued rotation results in failure within the load, characterized by a sliding of the top layers down the slope and a reduction in the angle of inclination. Further rotation again increases the angle, and the cycle repeats. If the speed is increased, there is continuous load failure and build-up and a continuous stream of rods or balls descends over the upcoming mass, which moves in circular arcs. At higher speeds the up-

Jan 1, 1961

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 Todd M. Ruff

This report summarizes ongoing research at the National Institute for Occupational Safety and Health, Spokane Research Laboratory, in which collision warning systems for surface mining dump trucks are being evaluated. Common accidents involve these large trucks running over smaller vehicles or pedestrian workers. Collision warning systems currently use one of several methods, including radar, radio-frequency-signal detection, or ultrasonic signals, to detect and warn of the presence of an object or person in the blind spots of the mining equipment. Most available systems have not been tested on large off-highway dump trucks. This report evaluates several systems on two sizes of trucks, a 50-ton-capacity truck commonly used in quarries and construction and a 240-ton-capacity truck commonly used in open-pit mines. Tests were conducted to determine false alarm rates, alarm effectiveness, and reliable detection zones for a person and a pickup truck. The results indicate that radar and radio-frequency identification systems show promise for this application and that several of the improved systems are ready for extensive field tests. However, challenges still exist in applying these technologies to large trucks.

Jan 11, 2000

By D. M. Abbott, H. J. Sandri

The geoscience matrix method has proven useful for valuing metallic mineral properties lacking delineated mineral resources or reserves. However, the method explicitly excludes commodity markets from the factors considered; marketability is assumed. When valuing industrial mineral properties, marketability cannot be assumed, it must considered. Market considerations may also significantly affect the standard weightings of geoscience matrix parameters such as the proximity to known deposits. In some cases, such proximity is desirable but in many cases it is undesirable. Application of the geoscience matrix method to industrial mineral properties therefore requires thoughtful, market-related adjustments to the basic geoscience matrix methodology.

Jan 1, 2000

By K. M. Li, Y. D. Zhang

The selection of stripping dragline is a complicated problem. Several factors, such as the deposit buried conditions, the demand of mine production rate, cast blasting result, the mining/stripping operation method and parameters, etc. may comprehensively influence the optimal selection of technical specifications of the dragline. Under these circumstances, the basic thinking and procedures for dragline selection are put forward as follows. •Step 1—Initially estimate the dragline annual stripping rate and stripping bench height according to the annual coal production rate and advancing speed of mining front. Then the feasible alternatives of dragline sizes can be calculated and selected from the existing dragline series. •Step 2—A computer simulation model is developed to simulate the dragline stripping operation, to obtain a series of working face parameters, then to select the best dragline alternative. This step can be interactively iterated until the satisfactory results are obtained. •Step 3— Sensitivity analysis can be done with the systems simulation model by changing the stripping bench parameters, e.g. stripping bench height and cut width, etc. to verify and modify the selection results if necessary. The mathematical model for dragline stripping simulation has been set up. The flowchart of the model is shown. A case study for a large surface coal mine with annual production rate of 16 Mt/a is followed. The dragline bucket capacity and operation radius, stripping bench height and cut width as well as other parameters are comprehensively optimized and selected. Keywords: Open cast, dragline, specification, selection, cast blasting

Jan 1, 2003

By Peter Metcalfe

"Wireless communication in the mineral processing environment is not as simple as it is in the home or office environment. The correct design of a wireless network in the mineral processing environment can offer a more flexible and lower cost installation than the transitional fiber networks. However with the flexibility of a wireless solution, also comes some limitations. By reviewing the plant requirements along with weighting the wireless benefits and limitations it is possible to design a network that combines the robustness of a wired solution with the mobility of a wireless solution. This paper addresses some wireless design considerations and it looks at some real life examples in the following areas: •,Meshed wireless network for high levels of redundancy •,Wireless instruments (such as HART, Modbus and others) •,Portable devices for mobile operators •,Network monitoring for plant personnel (it’s no longer just for IT people) INTRODUCTION Typical networks used in the mineral processing environment consist of a fiber network infrastructure with industrial switches used to connect the network devices. These fiber networks can be redundant or put into a ring topologies to offer a higher level of availability. Fiber networks have the benefits of: •,Immunity to noise from power and grounding issues •,Ability to span long distances (2km for multimode fiber and 20km for single mode fiber) •,Maintainable “off-the-shelf” technology Fiber networks however have some drawbacks, such as: •,Relativity high initial installation cost for cable trays, poles, trenches and pulling and termination of cable. •,Fixed geographic topology, adding future fiber drops may be challenging and expensive. •,Mobile users are not considered. Integrating a wireless network with a fiber network can offer the best of two worlds, a reliable high speed backbone for mission critical activities and a wireless network for remote applications and mobile users."

Jan 1, 2014

Safety rules for installing and using electrical equipment in and about coal mines covered in this information circular supersede those previously included in Bureau of Mines Bulletin 514, issued in 1952. This revision brings these rules up to date and more nearly in line with present operating and safety practices in the industry. The rules are intended to supplement existing Federal and State regulations, and no provision shall be construed to oppose or supersede any provisions of the Federal Mine Safety Codes, the Federal Coal Mine Safety Act, or the mining laws of any State. The rules were designed to permit progress, such as application of new or improved materials and equipment or use of new practices where these materials, equipment, or practices retain or improve the level of safety established by these requirements. It is hoped that they will fill the need for a concise edition for mine electricians and electrical engineers, especially those who do not have ready access to more detailed rules or codes.

Jan 1, 1964