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This publication summarizes, for all interested parties, the research, development, and demonstration in-house projects programed by the Bureau of Mines for fiscal year 1981 (October 1, 1980 - September 30, 1981) under its Minerals Health and Safety Technology program. The objective of these projects is to provide an ordered and sequenced series of advances toward the Bureau's overall goal of providing the system technology required to create a healthier and safer working environment for the Nation's mining and minerals processing workers.

Jan 1, 1981

By John Freeman

THE tensile properties of steels at elevated temperatures have been studied by numerous investigators,1 primarily for the purpose of determining their suitability for structural uses. Tests with this objective have been confined largely to the temperature range of approximately 20° to 500° C., because of the rapidly decreasing tensile strength at the latter temperature. Tests have also been extended to higher temperatures for the purpose of determining the most suitable forging range. This temperature range is also of theoretical interest. The phenomenon of increased tensile strength and decreased ductility in the so-called "blue-heat" range, approximately 200° to 300° C., is well known. It was suggested to the Bureau early in 1926 that a study of the properties of rail steels in this temperature range might prove of interest in relation to the studies of transverse-fissure failures in rails. There were available from another investigation3 several new rails from several different heats made to approximately the same specification requirements, the complete manufacturing histories of which were known. It was decided to determine, at least in the preliminary series of tests, only the ultimate tensile strength, elongation and reduction of area, because of the difficulty, time and cost involved in determining the proportional limit and yield point at elevated temperatures.

Jan 1, 1930

By L. C. So, S. Faucher, S. Mostaghel, A. Triwahyuono, D. Sauter, S. -Y. Oh, S. K. Lee, K. Aswin

"Molten hauling and water granulation are the commonly used slag treatment methods in the production of nickel. Water is present in these processes either to accelerate cooling of the dumped slag or in the granulation itself which creates an inherent safety risk of explosions. Even good design and operation are not sufficient to prevent explosions or injuries from occurring. Several dry methods to treat slags have been intensely studied. However, most of these technologies have never been commercialized due to numerous challenges including scalability, cost, low heat recovery efficiencies, and difficulties in heat utilization. Ecomaister-Hatch has recently developed and commercialized a reliable and simple Dry Atomization process, which eliminates water and allows for heat recovery. As part of the development towards other sectors, laboratory-scale and pilot-scale trials have been completed in a number of base metals and PGM facilities. Recently, Dry Atomization of a nickel laterite slag was successfully demonstrated at the laboratory-scale. The current paper introduces the technology and reports the test results obtained from atomization of the nickel slag.INTRODUCTION The processing of nickel laterites produces vast amounts of slag with over 90% of the feed to the furnace reporting as slag. Slag handing is therefore of critical importance to a laterite smelter. Traditionally there are two ways in which the slag is handled (1) Molten hauling, dumping, cooling and quarrying (2) Water granulation, dewatering, stockpiling. There are inherent disadvantages of both methods that will be outlined in this paper. An alternate route of Dry Atomization provides distinct advantages over the two conventional routes that are of particular interest to the nickel producer such as elimination of molten hauling, dumping and quarrying, elimination of water and improved safety. There is also the potential to convert the slag, which is typically regarded as a waste product, into a value added product and the continuous nature of slag tapping makes it amenable to heat recovery. Hatch has recently conducted laboratory-scale test work on laterite slag to demonstrate its viability for Dry Atomization. Results of this work are presented."

Jan 1, 2017

By R. F. Tenney

No detailed information has been published heretofore on the performance of small industrial-type anthracite stokers in building-heating service, apparently because of the difficulty of comparing the performance of one unit with that of another over an entire season's operation. Studies of competitive heating fuels have been similarly handicapped, and attempts to compare fuels are seldom technically sound in this investigation, the performance of a 60-in. Losch4 stoker burning rice-size anthracite in a standard commercial boiler was observed during a 4-month winter-spring season. It was used to heat two buildings at the Bureau of Mines' Anthracite Research Center at Schuylkill Haven, Pa., with the customary type of automatic pressure-range control. Attendance was limited to inspecting, fuel weighing, data recording, and ash removal. Results were computed daily and grouped by weekly periods to minimize daily irregularities. The same stoker-boiler unit had already been tested in a series of American Society of Mechanical Engineers (ASME) test code runs, with the stoker running continuously and with other conditions well stabilized A comparison of results from the code test and the building-heating tests provided information not available in the past for a single stoker unit, assisted in analyzing heat losses not computable in a cyclic operation, and established a basis for evaluating stoker performance in heating service.

Jan 1, 1963

By A. R. T. Denues

"INTRODUCTION The orienting phases of the current investigation of cushioned blasting in the Explosives Division of the Bureau of Mines were indicated in a previous publication (5) 3/. Pertinent literature reviewed therein indicated a highly controversial field. This emphasized the need for experimental studies of many factors that affect the health and safety of miners and the efficiency of mining operations. Results of some orienting tests showed marked effects on practical hazards. Further, they emphasized the necessity and importance of the contemplated investigation. The scope and general plan of these practical inquiries into the safety of cushioned blasting were indicated.This investigation of cushioned blasting relates to the various means employed to reduce the intensity of application of energy from explosive actions in boreholes. It has been suggested (from p. 19 of reference 5) that the divisions of this work would correspond to the salient hazards affected by cushioned blasting. These include the ignition hazard, hazards from poisonous gases, and other practical hazards in the blasting technique. The ignition hazard was resolved into two components of approximately equal weight. These include studies of effects upon (1) the incendivity of blown-out shots and upon (2) the occurrence of such shots. Experimental studies of effects on the incendivity of blown-out shots were first undertaken. Questions of the best procedure for making these evaluations have been adduced, and the interpretation and utilization of the results of gallery testing seemed to require detailed attention; some preliminary general considerations of such testing were therefore necessary."

Jan 1, 1943

By C. J. Newman

Prior to 1995, the smelting process at the Kennecott Utah Copper Corporation (KUCC) smelter consisted of Noranda reactors and Pierce-Smith converters. In the consideration of expansion opportunities, the existing process did not lend itself to a program geared towards processing the total output of KUCC mining and milling operations. During 1989 and 1990, a number of smelting options were evaluated. The final selection was the Outokumpu flash smelting process, coupled with the new Kennecott-Outokumpu flash converting technology. Facilities were designed and installed to process 1.0 million tonnes per year of copper concentrate, with the ability to expand to 1.2 million tonnes per year. Following the shutdown of the smelter facility utilizing the Noranda technology in May 1995, the flash smelting furnace commenced operation in June with the flash converting furnace startup following a few weeks later. The smelter has achieved design production targets and environmental goals. Current operating rates are at or above design rates for concentrate and matte processing. Emissions are lower than the permit levels and equate to less than 3.5 kg of S02 per tonne of copper. This paper outlines the design, construction, startup and the first two years of operation of the modernized KUCC smelter.

Jan 1, 1998

By E. Scheepers

The process under investigation is the large-scale production of phosphorus. Gravity delivers the feed, consisting of pelletised apatite, coke and silica (in the form of gravel), to a submerged arc furnace through ten, evenly distributed feed chutes ensuring constant packed bed volume. Within this packed bed, solid-gas reactions are dominant in generating the gaseous product. These reactions, as well as the packed bed itself, were the main focus in the development of a fully three-dimensional CFD model in which fluid flow and energy distribution are represented as functions of chemical reactions, heating and melting of material and heat losses. The associated complex process interactions necessitated the creation of two process-specific, user-developed models that integrates accurate, thermodynamical data with computational fluid dynamics calculations, as well as reaction kinetics. The boundary conditions are provided by industrial measurements, and the key model parameters of reaction kinetics were obtained by laboratory experiments for different feed mixtures. Thirteen temperature probes installed inside the refractory lining of the furnace especially for this project allowed parameter fitting and validation to be guided within the constraints of real measurements. Simulation results reveal a thin, dome-shaped, reductive zone where conditions are optimum for maximum phosphorus recovery, as well as evidence of a thermal reserve zone similar to an ironmaking blast furnace located above this reduction zone. When compared to actual operating data, the CFD model can successfully predict the specific power consumption, the phosphorus in the slag and gaseous product flowrate under given operating conditions. This CFD model forms part of a larger project that aims to create a Dynamic-CFD hybrid control model.

Jan 1, 2014

By M. Pearson, W. Bristowe, A. Hanson

"There's no such thing as quality assurance; only quality control ... by inspection. "(1) A common misunderstanding in the procurement and construction of custom designed, fabricated pressure vessels and piping systems is that quality assurance can be achieved by simply referencing codes, standards, ISO 9002, QMS or other such programs in the contract documents. In the authors' experience, nothing could be further from the truth, not detrimental to the performance of the equipment than the exclusion of inspection activities and reliance upon warranties and "fit-for-purpose" clauses. Likewise, the expectation that fabricators, suppliers, or third party inspectors can provide such assurances is also unrealistic where they have limited knowledge of the process, material selection criteria, or limited technical resources. The development and successful execution of a quality assurance program is a collaborative effort by engineers, designers, material suppliers, equipment fabricators, and field inspectors with the full understanding and support of the end user.This paper presents an outline of the quality control activities undertaken by the authors for several recently completed and on-going hydrometallurgical projects. The activities include: prequalification of fabricators and sub-vendors, shop audits, material validation testing, material source control and verification, positive material identification of weld metal overlay, specialised welding inspection, contamination control for titanium and titanium-clad fabrication, eddy current and mass spectrometer (helium) leak testing of shell-and-tube heat exchangers, hot cycle testing of titanium clad equipment, tolerance verification for refractory lined equipment, final inspection and cleaning.

Jan 1, 2004

By Patrizio Damiano

Competitiveness in Electric Arc Furnace production is pushing steelmakers to increase the throughput at the lowest expenditure. The technological challenge is therefore to operate the existing facilities at their top capabilities and to exploit materials and energy sources at the upmost yield and efficiency. Moreover, seizing the opportunity offered from the price variability of metallic feedstock calls for flexible practices, versatile equipment and tools to rapidly tune the melting profiles without hindering steel quality and equipment lifetime. The innovative Danieli Q-MELT Automatic EAF system addresses these aspects implementing a centralized control system which interacts with multiple technological packages. Each of these cutting-edge technologies focuses on one aspect of the EAF cycle, increasing machine availability and resource efficiency, by means of electrode regulation and foamy slag control, charging optimization, off-gas analysis and closed loop injectors control. Moreover, these modules provide the process supervisor application (Melt Model) with important information regarding the process status, thus allowing the adoption of a unified control strategy. The supervisor implements a robust statistical approach to identify process deviations in real time. The first results and technology perspectives inferred from the field immediately after the start-up are described in this paper.

Oct 30, 2017

By B L. Sainsbury, M F. Lee, A Penney

For most practical rock engineering purposes, stress versus strength conditions around underground openings for which rock masses fail and their various modes of failure, are reasonably well-understood and predictable. Some rock masses and particular rock types fail slowly and relatively quietly. However, others can fail rapidly, violently and maybe with the ejection of significant broken rock. In some countries and in some mines, the latter style of violent fracturing and failure of the rock mass is referred to as ‘strain bursting’. It can be alarming and extremely hazardous to nearby miners and machines. For such situations, the design and installation of appropriate ground support, to provide a safe work place, can be challenging. At any particular mine site, it’s often generally understood which local rock masses (rock types) are prone to strain bursting. Competent and strong siliceous rocks and some massive sulphides are often the main offenders. While some neighbouring, equally-competent and strong rocks might also fail, they do so more quietly and without ejection. To understand this contrast, a better understanding of the fracturing process is required other than simple and standard strength versus stress considerations. Suites of standard intact rock properties from numerous Australian mines have been used to define and help understand different high-stress failure styles for component intact rock; especially those prone to violent fracturing (strain bursting). Simple considerations of micro-fracturing (defects in the intact material), plus the available energy at failure versus the energy consumed during fracturing, distinguishes between over-stressed and competent rock types that fracture violently and those that don’t. CITATION:Lee, M F, Penney, A and Sainsbury, B L, 2018. Proneness of competent over-stressed intact rock to violent fracturing, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 170–184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By J. E. Williamson

Introduction 1. Factors on Which the Design of the Roaster Plant was Based The roasting operation at Lake Shore, it was realized from the outset, would be profitable only if costs and losses could be reduced to a low figure. It was absolutely imperative that the operation should be self roasting over the whole range of tonnages and sulphur grades which might obtain during the life of the mine. The roasting operation could not bear the cost in fuel and labour of even a partially fired roast. To meet this requirement, it was necessary to resort to additional insulation in the construction of the roaster and to provide a more flexible means of rabble cooling than the conventional water jacket (see p. 31). A second basic consideration was that of handling a wet, putty-like concentrate. The operating costs of a drier ruled out the possibility of drying the charge before feeding it to the roaster. Moreover, the dusting which would result from charging a dry product virtually all -40 micron (325 mesh) in size would seriously handicap the use of a dryer. Dust lubrication (p. 3S) due to the back-mixing action of the Edwards rabbles, and the use of a Sullivan slapper ( p. 27) on the concentrate filter, completely solved the problem of handling the roast feed. The third consideration was the reduction of dusting to a sufficiently low point that a Cottrell or other dust collecting system was unnecessary. The Edwards roaster when properly supervised, it is believed, can be operated to give the minimum possible dusting. At Lake Shore, the evidence has been that less than 1 per cent dusting occurs at any time and that the greater part of the dust produced is recovered either in the spray tower or in the dust chambers.

Jan 1, 1947

By Gordon T. Austin

The combined value of production of natural abrasives, which include tripoli, special silica stone, garnet, staurolite, and emery, increased in 1993. The increase in the value of tripoli production was the result of an increase in total production. Special silica stone experienced an increase in unit value but decrease in the quantity produced. Garnet showed a 19 % decrease in quantity and an 8 % decrease in value. Staurolite increased about 51 % in the quantity produced and 136 % in value compared with those of 1992. Staurolite's significant increase in value of production resulted from a 56 % increase in the unit value. The fused aluminum oxide industry showed an 8 % decrease in the quantity produced and a 13 % decrease in the value of production. The silicon carbide industry saw an 11 % decrease in the quantity produced and an 8 % decrease in the value of production. Combined, the industries decreased 9 % in quantity and 11 % in value compared with those of 1992.

Jan 1, 1993

By B. Holen, J. R. Baregi, J. A. Organiscak, A. B. Cecala

The National Institute for Occupational Safety and Health (NIOSH) cooperated with 3M Company in the design and testing of a new environmentally controlled primary crusher operator booth at the company’s Wausau granite quarry near Wausau, WI. This quarry had an older crusher booth without a central heating, ventilation and air conditioning (HVAC) system, and without an air filtration and pressurization system. A new replacement operator booth was designed and installed by 3M based on design considerations from past NIOSH research on enclosed cab filtration systems. NIOSH conducted pre-testing of the old booth and post-testing of the new booth to assess the new filtration and pressurization system’s effectiveness in controlling airborne dusts and particulates. The booth’s dust and particulate control effectiveness is described by its protection factor, expressed as a ratio of the outside to inside concentrations measured during testing. Results indicate that the old booth provided negligible airborne respirable dust protection and low particulate protection from the outside environment. The newly installed booth provided average respirable dust protection factors from 2 to 25 over five shifts of dust sampling with occasional worker ingress and egress from the booth, allowing some unfiltered contaminants to enter the enclosure. Shorter-term particle count testing outside and inside the booth under near-steady-state conditions, with no workers entering or exiting the booth, resulted in protection factors from 35 to 127 on 0.3- to 1.0-µm respirable size particulates under various HVAC airflow operating conditions.

Jan 1, 2015

By Bradford F. Townsend, Marc R. Kritzer, Michael F. Roach, Dennis Ofiara

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2008

By SAM YOUR

PROCESSING, technology and application of non- ferrous metals-copper, lead, zinc, aluminum, nickel, precious metals, foundry metallurgy, less common metals, secondary metals-are the special field of the Institute of Metals Division. New developments in this field during 1930 are more or less briefly out- lined in this review prepared by the papers and publications committee of the Institute of Metals Division as follows:

Jan 1, 1931

By Jack Bedder

"Editor’s note: We would like to thank those who make this annual issue possible. A special thank you goes out to the industrial minerals annual review editor, to the Industrial Minerals & 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.Ebrahim K. Tarshizi, member SME, of Michigan Tech, is chair of the Industrial Minerals &Aggregates Division’s Technical Committee.The technical committee vice chairs include: • Hyunjung Kim, member SME, of Chonbuk National University, agricultural materials.• Xihui Yin, member SME, of Kemira, ceramics and refractory materials.• Nikhil Gupta, member SME, of Virginia Tech, chemical raw materials.• Jasson Giddens and Swadhin Saurabh, members SME, of Oil Dri Corp of America and Mill Creek Engineering, respectively, chemical raw materials.• Snehamoy Chatterjee, member SME, of the Michigan Tech.• LeDeana Roberts and Shubham Verma, members SME, of Imerys and U.S. Oil Sands, respectively, fillers and pigments.• Thomas Hilderbrand and Kaiwu Huang, members SME, of Thiele Kaolin Co. and Virginia Tech, respectively, sorbents, filters and process aids.• Rhaghav Dubey and Edgar Blanco, members SME, of Outotec and FL Smidth, respectively, specialty mineralsAntimony generally occurs along with gold, lead, copper and silver. There are more than 100 antimony minerals, although the sulfide mineral stibnite is the main one.Antimony enters the supply chain either as a result of mining (primary production) or recycling (secondary production). China has by far the largest antimony resources and is, as a result, the world’s center for antimony mine production. In 2016, it accounted for more than three quarters of the global mine supply out of a world production figure of 130 kt (143,000 st), according to the U.S. Geological Survey. The biggest, and most high-grade deposits are found in southern China, with the largest mines located in Hunan, Guangxi and Yunnan provinces. Tajikistan, Russia, Australia and Bolivia are the largest mine producers outside China. A new antimony project in Oman made progress in 2016, producing first metal in April 2016 in test facilities, and then ordered three furnaces for a 26 kt/a (28,600 stpy) antimony metal and oxide smelter that is due on stream in late 2017.Antimony ingot production is not as widespread as is antimony mine production, owing to the high levels of pollution that are associated with antimony smelting. It is for this reason that smelting has been largely confined to China and other Asian countries, where environmental legislation is less stringent.Antimony oxide production is undertaken on four continents with China being the biggest producer. There is also a considerable amount of oxide production in Europe — which relies on imported feedstock, mostly from China. Antimony also enters the supply chain through recycling. Lead containing antimony is produced in a number of countries, mainly in secondary lead smelters. Typically, a blast furnace charge containing used or discarded battery plates, type metal or bearing metal is reduced to lead bullion, which is refined in reverberatory furnaces and melting pots. In the main, the antimony recovered is consumed in metallurgical applications. China was the biggest secondary antimony producer in 2016, and accounted for 25 retardants and lead-acid batteries. Flame retardants accounted for roughly 50 percent of consumption in 2016 with batteries representing about 25 percent. Other end uses include plastics and heat stabilizers, ceramics and glass and a variety of metallurgical applications. Demand has been sluggish since the global financial crisis, mostly because key markets failed to recover strongly from the downturn, particularly in Europe."

Jan 7, 2017

By Joseph D. Davis, GEORGE S. POPE

This bulletin is the fourth of a series a showing the results of the purchase of coal by the Government under specifications. The work of inspecting and analyzing coal delivered on Government contracts was transferred to the Bureau of Mines by an act of Congress effective July 1, 1910. It had been carried on for several years before that date by the technologic branch of the United States Geological Survey. The purchase of coal on the dealer's statement as to quality or on the reputation of the mine or district producing the coal is gradually being discontinued. At present most coal-purchasing contracts make definite provision regarding the desired heating value of a coal and the composition as shown by analysis. The heating value is usually expressed in British thermal units" and the composition specified is that shown by proximate" analysis. The price to be paid for delivered coal is made to depend on whether the analyses and heating-value tests of samples representing the delivery show the quality to be above or below the quality set forth in the contract. Large coal consumers are beginning to appreciate more and more the importance of the cost of power as a factor in the cost of producing a finished article. The endeavor to increase the efficiency and the economical operation of a power plant calls for an intimate knowledge of the quality of the coal being used. The purchase of coal under specifications insures the purchaser getting what he pays for and the coal being of the quality guaranteed. In addition, the analyses and tests of the delivered coal furnish data whereby the power-plant results can be comprehensively studied and a continuous check maintained on the conditions of operation.

Jan 1, 1912

By Alexander Fleischanderl

Steel market has become somehow unpredictable and requires quick adjustment in production conditions to survive in the harsh market environment. Steel production is not anymore driven by output records, but by efficient cost reduction measures to remain competitive under strongly varying production conditions. Energy efficient production and flexible raw material scenarios have become decisive factors to succeed and survive in our industry. Such scenarios have to be carefully investigated to be well prepared to adopt production steps continuously. The paper analyses various process opportunities to optimize energy and raw material consumption in the production route. Off-gas treatment systems have still a huge untapped potential to recover energy from the hot waste gases. This is valid for the EAF mini mills as well as for the integrated route. Various examples for waste heat recovery systems including resulting benefits are discussed for the EAF, agglomeration, blast furnace, direct reduction and BOF. New innovative bag-filter systems feature extremely low emission levels at lowest pressure loss and sound emission conditions. Also improved control and automation solutions support the operators to minimize the operation and maintenance costs of their off-gas system. Steelmaking by-products shall not be considered as residues, but as a valuable and cheap raw material source. The paper presents some show cases how to valorize slags as well as utilizing coke and iron oxide fines to increase productivity and minimize raw material cost. A new process for highly flexible converter steelmaking allowing for extraordinary high HBI and scrap rates above 50% and improved yield is discussed and evaluated

Oct 30, 2017

By Peter G. Mason

Over the last 15 years numerous Pressure Oxidation and Pressure Leach plants have been installed throughout the world. The technology is no longer regarded with awe and trepidation as plants designed to treat a wide range of feedstocks continue to be successfully brought on line. Important aspects of the design of such plants include feed preparation, slurry pumping, heating and heat recovery, pressure control and let-down, vessel design, safety and provision of associated services.

Jan 1, 1999

People in economically developed societies demonstrate inherent human care for Earth and want to stop pollution. Yet efforts to clean Earth seem bogged in confusion from wildly contradictory and alarmist predictions of æclimate crisisÆ. Supposed experts openly disagree yet weÆre told thereÆs universal agreement humans are causing æthe end of life as we know itÆ. The turmoil combines with peopleÆs feelings of fear, guilt, anger, hopelessness and even resignation and apathy to trigger æclimate alarmÆ. The paper enables people to rediscover clarity, hope and support for Earth by understanding how climate alarm and confusion were created and how they actually increase pollution. Many people seem to think global warming is as serious as pollution and worry that questioning alarm will enable pollution. Yet theyÆre different. We need be even more concerned about climate alarm because history shows repeatedly that when buried by ignorance and panic real problems grow overwhelming. Environmental credibility is endangered by confused politicians and sensationalist media. When weÆre willing to re-evaluate what weÆve been told we replace fear and confusion with facts and freedom to identify opportunities. Combining this with practical understanding of human behaviour and leadership enables opportunities to be identified and action taken. The paper shows how confident, informed leadership leads and supports higher productivity and effective care for the natural environment.

Jan 1, 2009