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By Peter Moser, Mark Ganster, Andreas Gaich

Surveying of a bench face before blasting is a pre-requisite for a proper blast planning and for a satisfying blasting result both in terms of safety and fragmentation. When surveying a bench face, preferably a large amount of measurement points are required in order to determine the geometry and especially the irregularities with sufficient accuracy. Only contact-free measuring systems allow evenly distributed measurements over the whole bench surface. Existing systems such as total station, laser profiler, or laser scanner show significant drawbacks such as that surveying results are just isolated values of the bench geometry such as heights or profiles, that borehole positions have to be defined in advance in order to know where to take profile measurements and that systems require special surveying skills and that they are expensive too. In order to overcome these difficulties and to provide the blasters a simple tool for bench surveying, blast design and layout and the subsequent back-transfer of the blast plan into the quarry, the Department of Mineral Resources& Petroleum Engineering of the University of Leoben, 3G Software & Measurement company and Mineral AB, one of the largest producers of aggregates in Europe formed a joint venture to develop a new system. Based on an existing stereophotogrammetric system for rock surface surveying and joint analysis (JointMetrix), a new tool was developed within a year. Apart from several mines and quarries using that new tool already today in the daily work, both the Department of Mineral Resources& Petroleum Engineering at the University of Leoben and Austin Powder GmbH Blasting Service did a lot of studies to determine the reliability of the new stereophotogrammetric blast surveying and planning system and its precision in comparison to classical laser surveying equipment. After 1 year of testing and comparison with laser based surveying instruments, it can be concluded, that the new technology of blast surveying& design systems based on stereophotogrammetry is suitable for being used in the daily work routine in quarries and mines. The comparison of the precision of laser based systems and stereophotogrammetric systems has shown, that the deviation between these two types of systems is less than 10 cm, in many cases even lower.

Jan 1, 2007

By Charles Hart

In this paper it is the author's intention to show the extent and character of foreign ores now known to be available; these deposits may be in active production or held in reserve until economic conditions may make them active. He hopes to show the relation existing between these ores and the American supply, and which of the former are now producing or will in turn come into production when our better ores have been exhausted. This phase of this discussion must of necessity include some data as to the present rate of consumption and a study of the changes we may expect here and abroad in the general steel trade and its sources of supply in raw materials. It is obvious that the occurrence of coal, ore and limestone in relation to one another and the proximity of a market are the elements in control of this feature of the problem. If the foregoing situation is favorable, all the other questions may be solved, for it is clear that with proper basic conditions finance, labor and operations will fall in line. We present a short outline of the present methods of carrying on the foreign iron ore trade, believing that it is of general interest in comparison with our own highly specialized methods, and that with the exhaustion of our better ores we will be compelled to seek a part of our supply abroad. A partial list of iron ores, with incomplete analyses (Table I), is added, to give a better understanding of the general situation and explain to some extent the reason for things being as they are in the iron and steel trade of the world and to help in bringing this paper to an informing conclusion. The question of the world supply of iron ores has been a subject for study on the part of geologists and engineers for many years, and found its best results in the Eleventh International Geological Congress, appropriately held at Stockholm, Sweden, in 1910. The proceedings are published in two volumes and are undoubtedly the best records available on this subject at the date of publication. It should be borne in mind, however, that much has happened in the 20 years since these figures were assembled. There is just as much known ore at present as at that time, minus the quantity consumed, plus newly discovered reserves. The World War had great effect upon this situation; during that time explorations were greatly reduced and the settlements after the

Jan 1, 1929

By F. Habashi

The Republic of South Africa is a heterogeneous mixture of Black Africans, Afrikaans, British, Indians, Malayans, French Huguenots, and many others from Europe and Asia. A decisive date in its recent history is the collapse of the Apartheid Regime in 1994. For a metallurgist, South Africa is the country of diamonds, gold, platinum, and many other metals. In 1887 Cecil Rhodes (1853-1902) was able to take control of the De Beers Mining Company after the discovery of diamonds at Kimberly in 1866. It was there where the so-called School of Mines was inaugurated in 1896.

Jan 1, 2010

By S. B. Bealko

In response to recent mining disasters and new mine rescue team legislation, NIOSH researchers conducted meetings across the United States with mine emergency response experts to investigate current needs and issues. Some of the issues include emergency response preparedness, mine rescue contests, real-life training capabilities, and training facilities. Many new teams are being formed that must be trained for mine rescue team competitions as well as be ready to respond to a variety of mine emergencies including a fire or explosion, a massive roof collapse, mine inundations, or vertical shaft rescue situations. Therefore, it is important that these teams are adequately prepared and trained. This paper presents a summary of domestic and international coal mine rescue training facilities and identifies those that provide unique, real-life, and/or state-of-the-art training. Research findings from this report will be used in further NIOSH investigations to improve coal mine rescue training. DISCLAIMER: The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Jan 1, 2009

By Parker A. J, Grimsey E. J

Studies have been carried out on the dead roasting of a copper-iron and a copper-nickel-iron sulfide concentrate, followed by segregation roasting with coal and leaching with either curpric sulfate in aqueous acetonitrile or cupric chloride in brine solution to preferentially solubilize copper. The effect of dead roasting and segregation roasting conditions on the overall leaching of copper and the separation of copper from iron and iron and nickel is reported. An excellent separation of copper from iron and a good separation of copper from iron and nickel can be obtained provided sulfur is removed to 0.5 per cent or less during the dead roast and provided the coal addition and temperature of the segregation roast are near the minima required for the segregation of copper.

Jan 1, 1983

By Guoqi He

Common offset seismic data collected over two active longwall panels at different stages of mining reveal that significant arrival time delays are produced in reflections from different levels within the mine cover. Mining-induced arrival time delays are also observed beyond the edges of the mine over unmined areas. Reflection arrival time delays increase with reflector depth and are laterally variable. The arrival time delays are produced by reductions of seismic velocity within the overburden. Reflection arrival time delays from a major strong unit located neutrally within the cover are proportional to subsidence, however, delays in other events are not.

Jan 1, 1989

In bump-prone coal mines, roof and rib support is subject to dynamic as well as static loading. Although less frequently encountered, the dynamic loading component can result in violent coal expulsions into openings seriously threatening the safety of workers. Dynamic support systems that have been increasingly implemented in many deep hard rock mines for dynamic failure containment have not yet found their adaptation to deep coal mines at desired levels. This paper examines the potential use of some of these dynamic support systems in deep coal mining, particularly in the western United States. Fundamental principles of dynamic loading are reviewed in the context of their application to dynamic failure mechanisms in coal mines. Potential benefits and applicability of the suitable hard rock dynamic support systems are discussed in relation to coal bump mitigation. The resulting insight provides a starting point for development of dynamic support elements for bump prone conditions in deep coal mines.

Jan 1, 2009

The basic objectives of mine roadways are to provide sufficient cross sections in order to meet the needs of accommodation of equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. The damaging of a roadway is a result of several factors including geological properties of surrounding strata, method of roadway formation, type and spacing of support and so on. Among these factors, strata conditions play an important effect on the stability of roadway. Weak rocks cause excessive roadway closures and water softens some rocks and promotes the closure problem. In this paper, a scientific discussion on the effect of water on the stability of roadways is given on the basis of results obtained by means of in-situ investigation and laboratory rock tests.

Jan 1, 1996

By O. Naiker, T. Riley

Keywords: Pyrometallurgy, furnace, Xstrata, ferrochromium, Premus Technology The presentation will give a basic overview of Xstrata Alloys. Included will be a brief history of the Alloys division as well as of each plant within the division. The Xstrata chrome plants utilise a wide variety of production processes, including Xstrata's Premus process, the Outokumpu process, and the conventional process. Xstrata?s Lion Project is underway, with commissioning expected in the third quarter of 2006. The new smelter will utilize Xstrata?s patented Premus process, and the competitiveness of the Premus process is discussed.

Jan 1, 2006

This method determines tellurium at concentrations down to 0·01 p.p.m., with geochemical accuracy. Tellurium is volatilized from the rock at 800°C in the presence of sulphur from decomposing pyrite, condensed, dissolved, and finally determined by atomic absorption in a long tube burner. The distribution of Te is shown near some gold lodes at Kalgoorlie. Lastly, a method of synthesizing Te-free pyrite from sulphur and ferrous sulphate is described.

Jan 1, 1969

A thermochemical model is developed to study the two-stage smelting reduction process for ironmaking without post-combustion. Steady-state multi-material and heat balance equations are solved simultaneously to study the effect of metallisation, slag basicity, coal rank and heat loss on consumption rates of coal, ore, flux and oxygen and production rate of slag to produce hot metal of a given composition, tapped at a given temperature. The model is applied to the commercial data for a COREX-plant producing a wide range of hot metal compositions, tapped at different temperatures. The computed rates of coal, slag, flux, ore and oxygen were found to be close to the reported ones, but an exact match could not be obtained. It is found that a four per cent change in metallisation brings changes the coal rate by five per cent, flux rate by six per cent, slag rate by eight per cent and oxygen rate by 13 per cent, while a ten per cent change in basicity changes the coal rate by ten per cent, flux rate by 13 per cent and oxygen rate by 22 per cent. Further, it is found that an increase in metallisation decreases the coal rate and export gas. At a given per cent metallisation, the coal rate and the export gas are lowest for anthracite compared to all other types of coal.

Jan 1, 1999

By G. van Hout, D. Rahal

Caving is a mass mining method that is normally applied to large, low grade orebodies because of its low production cost and high capacity. However, equipment breakdown and poor draw management can cause mining costs to exceed that of all other mining methods. One way to minimize the effect of disruptions in the mining cycle is to use Mixed Integer Linear Programming (MILP) for long-term scheduling. This paper describes a MILP goal program which has the dual objectives of minimizing deviation from the ideal draw profile while achieving a production target. Schedule optimization is performed using a life of mine approach in which all production periods are optimized simultaneously. The underlying assumption being that material mixing in the short-term (between monthly optimization cycles) has a minimal effect on the long-term state of the panel. Schedule optimization is carried out using six general constraint types to model and control production. The constraint types define: deviation from ideal practice, panel state, material flow conservation, production quality, material flow capacity and production control. These constraints define production targets and drive production toward the ideal profile while maintaining correct mining practice. Application of the model using production scheduling data for a De Beers kimberlite mine. It is shown how different production control constraints regulate production from individual drawpoints as well as recovery of the ideal panel profile by implementing an optimised draw schedule.

Jan 1, 2003

A massive cobalt-containing pyrite orebody occurs in banded albite-quartz-biotite rocks at Thackaringa, some 30 km SW of Broken Hill. Because of the world-wide shortage of cobalt during the late 1970s, serious consideration was given to the development of a suitable flow-sheet to recover the cobalt from this ore. Details of a pressure leaching process in which more than 90 per cent of the cobalt is extracted from a pyrite concentrate are presented.

Jan 1, 1983

By Poul Hansen

"In mid-I986, a world-class mining enterprise was created in British Columbia, bringing together the copper mining operations of Lornex Mining Corporation and Cominco into a new entity, Highland Valley Copper. This paper will focus on the background and rationalef or the formation of this partnership, the resulting operating changes and the productivity and cost benefits expected.IntroductionSince the deterioration of the world copper industry in 1981, the future of the Lomex and Cominco mines in the Highland Valley of British Columbia looked increasingly precarious. Despite the expansion of the Lomex mill complex in 1981 to one of the world's most cost-efficient copper and molybdenum concentrators, persistent low metal prices had made the remainder of the ore in the Lomex orebody marginally economic and had significantly foreshortened the expected life of the operation.Cominco had acquired the Bethlehem Copper assets in order to consolidate its ownership of the Valley orebody, and was feeding the Bethlehem concentrator with ore from the Valley orebody. In spite of the high grade and free-milling character of the Valley ore, profitability of the Cominco operation was severely restricted because of the limited capacity of the Bethlehem concentrator and its location high on the hillside above the orebody."

Jan 1, 1987

When asked to lecture at Bendigo on the geological factors that determine the depths of ore deposits, I hesitated for a little before agreeing to lecture on the theory of deep ores in the city world famous as the pioneer of deep gold mining. If there be one place, wherein the conditions of deep-seated ore deposits should be sufficiently well understood, it is the city where the 180 mine made its bold plunge to previously neglected depths; and where the record of that famous mine has been broken by the skill of the managers, and the pluck of the proprietors, of the New Chum Railway and Lazarus mines.In the face of such practical triumphs, theoretical discussion may seem a waste of time, especially since it is often dedared that the existence of such deep-seated ores was denied by geological theory. This assertion is, however, startling since the oldest and best supported geoiogical theory of ore deposits, has taught for more than a century tliat ores must descend far below the regions of practical mining. This charge against Victorian geologists is generally based on opinions attributed to the late Sir Fredrick McCoy. It has been repeatedly affirmed that he declared that gold cannot occur pelow a depth of 300 feet. But so far I have not been able to discover that McCoy ever made any such assertion or ever held such a view.

Jan 1, 1902

By Robert E. Fosse

Driven 14-inch-square concrete piles were used as the foundations of Genentech Hall at the new University of California, San Francisco Mission Bay Campus. The five-story, steel eccentrically-braced frame building is currently under construction at a 43-acre property located in a former large shallow marshy inlet from San Francisco Bay. The piles were driven through 10 to 25 feet of fill and 20 to 60 feet of soft compressible Bay Mud into an underlying dense sand layer. Pile design capacities were developed for traditional allowable stress design, load factor and resistance design, and ultimate design criteria. The ultimate level capacities were for checks of loads occurring when the links in the eccentrically-braced frame yield during an earthquake. A load test program was performed to confirm pile design recommendations. Two test pile locations were selected for compression, tension, and lateral load tests to evaluate pile capacity and pile/soil stiffness under long-term, short-term and rapid loading conditions. Maximum test loads were 1000 kips downward, 350 kips uplift and 50 kips lateral. Foundation construction began by driving 34 indicator piles with a Delmag D46-32 diesel hammer of 113 foot-kips maximum rated energy. All indicator piles were monitored during initial driving using the Pile Driving Analyzer. Restrike data, obtained several days after initial driving, indicated significant pile-soil setup and typical pile capacity increases from 750 to 1000 kips. The majority of the 1242 production piles were then driven to acceptance criteria of 75 blows per foot and a minimum embedment of 10 feet into the dense sand bearing layer. Piles driven to full length without achieving the blowcount criteria were evaluated on a case-by-case basis. Acceptance of these piles was established by evaluating restrike data.

Jan 1, 2002

During the drilling campaign conducted between October, 1942; and May, 1943, to prove the extent of the scheelite deposit worked by King Island Scheelite N.L. at Grassy, King Island, Tasmania, 35 holes were drilled and 606 samples recovered and assayed for their content. Of these, 238 came from outside the limits of the orebody and were for the most part barren, although a few contained some scheelite. The present statistical analysis is made only of the 368 samples taken from diamond-drill cores of the orebody itself.Drilling Pattern and Sampling MethodsFrom the purely statistical viewpoint, it is realised that methods employed in selecting sites for diamong.-drilling, and of collecting samples from drill cores, do not give a completely unbiassed set of data for analysis. Fig. 1 is a sketch plan showing the relativepositions of the drillholes, which were inclined at an angle of depression of 50 deg. The pattern does not conform to a properly randomized and' regularly-spaced grid, the positions of the later holes being determined by the results obtained from previous holes.Statistically, the bias is, therefore, favourable. The unequal spacing of the drill holes and the lack of uniformity in direction of the lines along which the holes were drilled are unsatisfactory from the mathematical viewpoint; but it is realised that these irregularitiesare difficult to avoid in determining by the most economical methods the extent of such an orebody, and are dictated by geological rather than mathematical necessity.Sampling, also, is lacking in complete uniformity. Each sample is approximately 10ft. in length. However, owing to the fact that 100% recovery of core is rarely achieved, and actual lengths of samples taken are ,primarily governed by the length of the drill runs,and secondarily by lithological changes, there is a considerable amount of variation in the sample length.AssayingWith the exception of 28 samples from three drill holes all samples dealt with in this paper were assayed in the Melbourne University Ore-Dressing Laboratory of the Commonwealth Scientific and Industrial Research Organisation. These assays were given to the nearest 0.05% WOg as it was considered that more accurate determination was not possible. This fact has been taken into consideration in the frequency analysis below. The 28 assays determined by the Tasmanian Mines Department were given to the nearest 0.01%.

Jan 1, 1950

By S. H. Badenhorst

Zacharias Lewala discovered a diamond at Grasplatz, near Lüderitz in April 1908. While this stone may not have been the first diamond to be found in this barren, inhospitable area, it most certainly was the stone that set off a chain reaction ultimately leading to the creation of Namdeb as we know it today. [ ]

Jan 1, 2003

Editor?s note: Each year, the June issue of Mining Engineering features an industrial minerals review. Several people put in a fair amount of time in developing the material for this issue, all the while doing their own jobs. Thank you to the industrial minerals annual review editor, to the Industrial Minerals and Aggregates Division technical committee chair and vice-chairs, and to the authors of the individual commodity profiles. Jim Norman, member SME, of Tetra Tech, is the industrial minerals annual review editor. Candace Trimble, member SME, of Oil-Dri Corporation of America, is chair of the Industrial Minerals and Aggregates Division?s Technical Committee.

Jan 1, 2012

By Mark Sanders

This report compares a proposed 10/60 "piggyback" 02 generating self-rescue unit to the standard CO self-rescue unit with respect to work task interference. A simulated low seam coal mine was constructed and subjects performed locomotion, shoveling, cart pushing, and timbering tasks with the 10/60 or self-rescuer attached to their belts. Task completion time was longer on all tasks when wearing the 10/60 unit, although only locomotion was statistically significant. The 10/60 unit was bumped over 100% more often than the standard self-rescuer. Implications for design of the proposed 10/60 container are: 1) unit?s container must be extra durable to withstand the added abuse it is likely to receive by low coal miners; and 2) extra consideration must be given to preventing the device from slipping on the belt while working, especially in low coal.

Jan 1, 1980