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By Moe Momayez

Shotcrete is a practical and economical support system in many Canadian underground mines. Although shotcrete technology has gained acceptance in the mining industry, there are some problems that have emerged with respect to quality assessment and thickness measurement of the liner. This paper presents recent tests performed with a miniature seismic reflection device developed primarily for thickness measurement of this heterogeneous liner. Work was performed on site in an underground mine in Ontario, Canada. This paper also presents the results from laboratory tests performed on fibre reinforced and non-reinforced shotcrete panels that were used to assess the P-wave velocity in both materials. The results of these tests were used in a second on site investigation. The NDT thickness measurements showed good agreement with direct thickness measurement such as coring.

May 1, 2001

By King K. Mak

The objectives of this study are to: (1) Assess current signing regulations and practices; (2) Develop effective signing guidelines; and (3) Evaluate the applicability and appropriateness of the proposed signing guidelines through field demonstration at representative mines. A literature search was conducted to determine the state of the art for signing applicable to surface mine haulage roads as well as survey of existing MHSA regulations and review of MSHA accident records. Nine representative mines were visited to gather information on current signing practices. Preliminary signing guidelines were then developed based on the abovementioned data. Field demonstration of the preliminary signing guidelines was conducted in which signing programs were implemented in two selected mines. Signing requirements were first assessed at each of the two participating mines. Subsequently, the necessary signs were designed, purchased, and installed at the two mines. Evaluation of the signing program as to its adequacy, appropriateness, and effectiveness was solicited from both mine management and operations personnel. Experiences gained from field evaluation were then incorporated into the final signing guidelines as presented in this final report.

Jan 1, 1981

In 1948, it became clear that the ventilation system of The Zinc Corporation Limited and New Broken Hill Consolidated Limited mines, would be inadequate for future operations. The,paper describes in detail the process of designing an entirely new ventilation system for a large underground mining operation. The system was based on a single new upcast airway to be located on the boundary of the two properties, which were to be ventilated in parallel as two separate ventilating districts.From calculations of resistance, and assessments of future air requirements, the duties of a new exhaust fan to be located on the collar of the upcast airway were specified as 700,000 cubic feet per minute at 2·6 in. w.g. total pressure for initial operation in 1953 increasing to a maximum of 900,000 c.f.m. at 3·6 in. w:g. total pressure ten years later. The economic size of the new airway was calculated from a consideration of the first thirty years operation of the system, and it was decided to provide a 20 ft. diameter concrete-lined shaft.The new system went into operation five years after the initial planning, and the effect of the difference between actual and predicted rates and distribution or production are discussed. The final result was entirely satisfactory.INTRODUCTIONThe first proposal for an investigation of The Zinc Corporation Limited-New Broken Hill Consolidated Limited ventilation system with a view to putting it on a proper technical basis was made in 1938. A new Main Shaft was then being sunk, and it was decided to postpone the enquiry until this had been completed to No. 14 Level, when operations would be temporarily suspended and the shaft commence to operate as a major airway. The investigation was completed early in 1940, when Z.C. Ltd. upcast fan was...

Jan 1, 1956

By S. G. Malghan

W.H. Moyer In reference to the section “Excess pyrite, ” the author discusses difficulties in separating chalcopyrite from pyrite. A technique does exist, and has been used commercially, for the flotation, separation, and recovery, if desired, of both chalcopyrite and pyrite. The method was described in Mining Engineering, March 1966, “An Improved Flotation Method for Cornwall Sulfides. ” While it was not used on a porphyry copper ore, it was used on a chalcopyrite - pyrite-containing ore and might well have application. Both sulfides, chalcopyrite and pyrite, were floated simultaneously using xanthate as a collector and MIBC frother to produce a cleaned sulfide product. This concentrate was then thickened and conditioned at high solids with aeration and lime to a pH above 12.0 for a period of 1.5 to 2 hr. A supplemental suppressant, such as cyanide, could be used if necessary to sharpen the subsequent separation; however, it was not required at Cornwall. The conditioned sulfides were floated with two stages of cleaning to produce a highgrade chalcopyrite froth product and a pyrite sink product barren in copper. The separation at Cornwall gave a 28.6q. Cu grade chalcopyrite product and a pyrite analyzing 0.0670 Cu. A desliming step on the raw ore initially used at Cornwall for a period of time was later discontinued. Advantages to be found in using a strong sulfide collector, such as a xanthate, is the rapid flotation it induces and, generally, an ability to float at a coarser grind. A following regrind circuit could be used to give maximum liberation and produce a clean sulfide concentration. The “differential” separation is concerned primarily with grade and with assuring a barren pyrite for maximum recovery.

Jan 11, 1986

By Y. F. Bulgakov, Y. V. Melnikova, V. S. Zakharov

A new technology of atmosphere in inertization of fire section with the help of gazeous nitrogen is presented in the report. This technology is based on membrane air subdivision into two streams, concentrated with nitrogen (up to 99%) and with oxygen correspondently with subsequent giving them into the place of fire. This technology belongs to environmentally friendly ones and it has a great number of technical, mobile and economic advantages comparing with the rest of well-known methods of fire extinguishing. This technology application in Ukrainian coal mines allowed to reduce the member of isolated places of fire at the expense of their extinguishing efficiency.

Jan 1, 2003

By William S. Miska

The study is an economic evaluation of historical, current, and projected refractory uses in the iron and steel industry of the United States. The first part of the report presents a refractories classification and identifies principal trends in the refractories industry; such as, value and volume of shipments, prices of finished refractory products, the number of manufacturers and plants for refractories production and marketing. The main part of the report treats refractory use patterns and technologic developments affecting refractories usage in the iron and steel industry. Changes in use patterns in each furnace type, refractory, and installation costs and the future outlook for refractories in ironrnaking and steelmaking are covered. The last part of the report identifies the principal raw materials used in refractories production and treats trends in refractory raw material consumption. An appendix to the report contains historical time series graphs of shipments of refractory types used primarily by the iron and steel industry and principal refractory raw materials sold or used by producers. An equation of the line of best fit was calculated from the earliest to the latest year in each time series, usually 1950 to 1965; these were extrapolated in order to derive volume estimates for the year 1975.

Jan 1, 1968

By P. van der Veen

The objective of this paper is to analyze the evolution of the strategic drivers of the mining sec-tor over the last half century, which has been guided by a varying and expanding list of motivations. While companies cannot survive for long unless they are making profits, the strategic drivers of the industry have gone far beyond profits since at least the mid-1970s when environmental concerns began to be taken seriously. For the most part, these forces have followed global trends and public opinion, but they have been shaped and magnified by the significant, often dominant role that the mining sector plays in many economies. While the mining sector used to be primarily motivated by the first pillar of sustainable development -i.e. the economics pillar-, in the 1970s the second environmental pillar became an important factor in decision making, and in the 1990s the third social pillar emerged as a major driver.1 The entrance of new strategic drivers has also had considerable impact on technological and organizational developments in the mining industry; however, technological changes, driven by cost reduction considerations, have in turn impacted the strategic drivers of the industry, resulting in the need for further technological and organizational developments.

Jan 1, 2007

By Rundqvist

The best method to minimise disturbances from traffic to the neighbourhood and in Urban is probably to go underground. For obvious reasons this will cause vibrations, noise and other environmental effects which need very strict regulations and quality assurance in order to complete the work successfully. One project is “Southern Link”, a part of a ring road system. The system of tunnels includes 16 kilometres of tunnels right beneath the south part of the city of Stockholm. At least 20.000 people will be or could be affected by different kinds of disturbances and pollution such as vibrations, noise, gas and groundwater. Another project is the “Arlanda Link”. A new railway with three stations has been built under the existing and running to Arlanda airport with its terminals. Authorities have carefully judged these projects, which cause complaints from neighbours due to disturbances. The blasting operations are professionally managed by the contractors and controlled by consultants to keep the regulations according to the Swedish standards, which are well described in the tender documents by risk analysis and technical descriptions. In spite of that, one conclusion is that it is not always possible to go underground without exceeding stipulated regulations with existing technique. Some of the regulations also double the cost of excavation

Jan 1, 2001

By Z. G. Lin

In Xian, China, compaction by means of soil (or lime-soil) piles is one of the effective methods widely used for densifying loess and eliminating its collapsibility. However, as a result of groundwater table rising, it is no longer applicable in many areas. This paper is the summary of the first-time use in Xian of sand-gravel compaction piles aimed at densifying the miscellaneous fill (already partially under water) and saturated loess at a certain project site. In-situ tests, conducted before and after the treatment and including several kinds of penetration tests backed up and confirmed by a set of plate loading tests, yielded very satisfactory results, strongly testifying to the viability of the method.

Jan 1, 2010

By Elaine T. Bowers

The Sunnyside single-entry project pioneered the use of single entries for longwall development in this country. During the 10-year course of the project, an immense amount of information was gathered. Over three miles of entries were observed primarily through instrument groupings placed in strategically located areas or "rooms." Nearly 1,200 instruments were monitored to gain information on the behavior of coal entries during development stages and through the mining of two longwall panels. This was one of the most extensively documented projects undertaken by the Bureau, The data gathered has a great potential for scientific research especially in the area of longwall mining. This Bureau of Mines report presents the ground control data gathered, in the form of computerized plots. Roof-to-floor deformation and load on cribs and roof bolts make up the bulk of the data, which is presented as load or deformation versus time. The plots are organized, generally, by the three main entries involved and, specifically, by the individual areas or rooms in those entries. No major attempt will be made, in this paper, to analyze the data other than to identify its source arid its history.

Jan 1, 1983

By William L. Crentz

In a Nation-wide appraisal of coking-coal reserves and of the practicability of upgrading marginal deposits to metallurgical standards, this study of the preparation characteristics of the coals in Cambria County, Pa. , was undertaken. Over 90 percent of the coal remaining in Cambria Comity is found in the Upper Freeport, Lower Freeport, Upper Kittanning, and Lower Kittanning beds. The Middle Kittanning bed, although mined on a commercial scale in the past, is not an important bed now, as most of the remaining reserves are too thin to be mined over wide areas. For many years, Cambria County has been an important source of coal for industrial and metallurgical purposes. The) principal production comes from the Lower Kittanning bed, which accounts for almost .60 percent of the Cambria County coal output. Table 1 shows the county's coal production, by beds, during 1948.

Jan 1, 1950

By F. Stober, D. Wanblad, J. Ndlovu, L. R. Nelson, L. P. S. de Villiers

The single six-in-line furnace of the Polokwane Smelter is the largest installed high-intensity furnace for platinum group metals (PGM) base metals sulphide smelting in the world. The furnace employs state-of-the art technology to deliver a planned throughput of 650 000 t/a dry concentrate at a design 68 MW power input. This furnace, at double the capacity of previously existing PGM furnaces, offers low unit operating and capital cost through the resulting economies of scale. Key features of the design include:

Jan 1, 2005

By O. T. Barrett, R. F. Aberethy, H. N. Cooper, Thomas Fraer, William L. Crentz

"INTRODUCTION The object of the techniques described in this report is to determine the possibilities of separating the components of a raw coal into such grades as may be necessary to recover some exceptionally clean functions for special purposes.To do this commercial gravity methods would require separation at very low specific gravities, entirely outside the range of conventional practice. Hence, a technique has been developed for breaking down cool ample, into very close fractions within the gravity range of the (-lean coal matter as well as for separating it from the refuse and particles.Such data on the fundamental specific-gravity consist of the clean-coal matter will serve to appraise the difficulty of the problem and to chow be accomplished if and when effective methods of making such separations commercially are developed."

May 1, 1945

By S. J. Thiele, T. Newton, W. Magalhäes, T. Takayama, J. Welsh

Companhia Paraibuna de Metais (CPM) is presently pursuing a zinc production expansion project. Besides increasing production, the goal of the project is to address existing problems while providing a platform for a proposed twofold increase in production in 2003/2004. Therefore, the current expansion strategy was formulated to address present and future requirements. Computer simulation modeling and full scale plant testing are being used to generate data to optimize the operating conditions and to perform a sensitivity analysis. The initial phase of the project, which will boost CPM's capacity to 86,000 t/y of marketable zinc, is to be completed in September 2000.

Jan 1, 2000

By Joseph T. Singewald

The possible value of the red hematite iron ore of the southern Appalachian States, if some practicable method of concentrating it could be devised, has long been recognized. The ore is very low grade, and although in enormous quantities, particularly in the States of Alabama, Tennessee, and Georgia, is only at a few points rich enough to work, and even the best of it ranks among the lowest grade iron ores being mined in the United States. A cheap method of beneficiating this ore would make enormous quantities available and vastly increase the iron-ore resources of the country. However, this low-grade ore in effect constitutes a potential iron reserve, and as long as ample quantities of ore can be obtained elsewhere the question of its utilization does not demand immediate notice. Where these ores are in part of workable grade, however, a problem of more immediate importance arises which, from considerations of economy and prevention of waste in their mining, ought to be solved or, at least, attacked as quickly as possible. Where these ores are being worked they are usually intimately associated with lower-grade material that in mining is left behind. The difficulty and expense of going into ground broken by old workings makes the recovery of this lower-grade ore practically impossible and it is lost forever. Success in concentrating the red ores, therefore, would save material that is now being irretrievably lost. The successful large-scale concentration of law-grade ore in the last few years on the Lake Superior iron ranges should encourage the attack of similar problems in the Birmingham district.

Jan 1, 1917

By Michael W. Redifer

A Fortran IV computer program was developed to calculate the composition at equilibrium of products from a set of high-temperature gas combustion reactions. The program was used to develop high-temperature equilibrium concentration profiles for various constituents as a function of temperature and oxygen concentration. The computer program was specifically applied to reactions pertaining to the corrosion of superheater tubes in pulverized coal-fired boilers; however, it is useful for any multicomponent, multireaction scheme in which equilibrium constant data can be obtained and is comprised of gaseous reactants along with finely dispersed solids or liquids. General applicability of the computer program, including its limitations, are discussed along with detailed instructions for using the program.

Jan 1, 1973

On the first of October 1991 two significant pieces of legislation came into force. Both of these are relevant to the allocation and use of minerals in New Zealand . They are the Crown Minerals Act 1991 and the Resource Management Act 1991.   The full legal implications of these is not fully known because the Planning Tribunal and the superior courts have not as yet had to deal with them in any detail. However, the thrust of the legislation is clear and it is appropriate to give an overview of how the statutes will operate in tandem if you are seeking to pursue or oppose any prospect, exploration or mining of Crown Minerals in New Zealand.

Jan 1, 1992

By Kelvin K. Wu, George H. Gardner

On July 24, 2002, a nonfatal entrapment accident occurred at the Quecreek #1 Mine, Black Wolf Coal Company, when an active mining section inadvertently cut into a flooded abandoned mine. This incident, and the dramatic rescue which ensued, brought national attention to a common problem in the coal mining industry. Since 1995, there have been more than 100 inundations at coal mines in the United States. Unavailable, inaccurate, or incomplete mapping of older abandoned mines is typically responsible. Serious problems associated with accidental discharges of fluid mine waste material (slurry) and water from coal refuse disposal facilities have resulted from similar causes. Recent problems related to the inaccurate location of old abandoned mine works have increased the interest in the use of conventional and emerging drilling and geophysical techniques for detection of air-filled and water-filled cavities. The United States Congress has committed significant funding toward investigating the applicability of these technologies. MSHA actively promotes the use of the best available technology to minimize the significant adverse safety and environmental consequences associated with unplanned breakthroughs and inundations. This paper provides background information and a general summary of the MSHA-sponsored field demonstration projects which are currently in progress. Potential benefits and limitations are discussed. The need for field verification/ground-truthing is emphasized. Under appropriate conditions, geophysical methods can be effectively integrated into a comprehensive field exploration program.

Jan 1, 2005

By James W. Wade

This paper describing the mining practices at the Tintic Standard mine is one of a series being prepared by the United States Bureau of Mines. In the preparation of this paper each subject has been presented by the engineer in charge. L. R. Dobbs wrote the part pertaining to tae technique of square-set mining, J. M. Snow the part on geology, and M. D. Paine, the part on ventilation. All of the drawings are the work of H. W. Waterfield of the engineering department. The statistics of the Tintic district ware prepared by A. G. MacKenzie. Each writer has attempted to show the difficulties that arise in operating and the practices used to overcome them.

Jan 1, 1930

By Paul W. Johnson

A computer program for calculating capital and operating costs from material and energy requirements and equipment costs for use in preparing cost estimates for metallurgical process evaluations has been written by the Bureau of Mines' College Park process evaluation group. The program permits rapid recalculation of processing costs when changes of data or equipment are desired, and produces tables of capital and operating costs suitable for publication. Equipment cost summary tables for each process section end supplemental information for input-data checking is included in the computer printout. The program is written in Fortran IV except for several subroutines which are written in machine assembly language for the IBM 7094.3 With a few modifications, the program can be used on other computers.

Jan 1, 1969