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By Stanislatv Pawlowski

New, large sulphur deposits were discovered in Poland in 1953, the result of investigations by the National Geological Institute. All deposits occur in a widespread Miocene evaporite unit in the Carpathian foredeep. The gypsum underlying impermeable Sarmatian clays was altered to limestone and native sulphur where penetrated by hydrocarbons and bacteria. All deposits occur in Miocene structural uplifts. The early determination of the genesis of the sulphur deposits and their occurrence in elevated blocks led to an exploration program that successfully located new deposits.

Jan 1, 1978

By Jenna Wundrack, Evan Thibaud

The advanced cryogenic treatment is a post-manufacturing metallurgical process that involves subjecting off-theshelf materials to extremely low temperatures, significantly improving wear resistance and reliability. These case studies explore whether the claims of Enrich Bits & Tools benefit metals and their specific in-field application to drill bits in the blasting industry. This paper reviews the application of the treatment to button drill bits for enhanced wear resistance in two operations. The first is a civil construction project with highly abrasive rock. To confirm the remarkable benefits of the treatment, a second case study was performed. This case study utilized measure-while-drilling technology in consistent rock characteristics to reduce variables in the field study.

Feb 1, 2024

"What is your history and how did you get involved in mining?Like many SME members, I came from a mining community with a family history in mining, in my case Walkerville, MT. Both of my grandfathers were underground miners. My father was a miner for a short time. He later sold drinks to the miners. Unfathomable by today’s standards, my dad would pick up the miners’ checks at the pay office and have them cashed and waiting with a shot and beer for the miners when their shift ended. My mother was a nurse, who from time to time, would patch up an unfortunate miner. I remember walking past multiple picket lines on the way to and from grade school, watching homes being boarded-up. I grew up with a deep respect for the critical relationship between labor and management.I had no intention of going into mining and initially set out to pursue a career in chemical engineering. But I attended my first two years of engineering at Montana Tech, due to the proximity and affordability. This is where I met Dr. Tom Finch, a mining professor who taught statics to the engineering students. After a coaching session in a hallway, half way through my sophomore year, I switched to mineral processing engineering. In his colorful way, Professor Finch advised me that, “You do not want to make #@*!! erasers and #@*!! Jell-O the rest of your life go talk to the guys in mineral processing.” He was very persuasive and here I am today.How about your involvement with SME?I encountered SME out of school and a little later in my career. Terry Maio and Jim Arnold invited me to local section meetings in the Missouri Lead Belt. That was my first exposure to the technical programming and relationship building that was possible at the local level. After Ozark Lead shut down and I relocated to Nevada, Rich Johnson, Scott Barr and Dave Collins encouraged me to attend my first annual meeting in Salt Lake City, UT. I joined SME at that time and was fortunate to be engaged by members like Art Schweizer and Jim Arnold, and I soon began the leadership progression for the Mineral & Metallurgical Processing Division. Since then, I have supported SME at the national and the local level serving in multiple roles and capacities."

Mar 1, 2017

By James Warren Andrews

The values of saturated water vapor pressure from steam tables have been found to be inaccurate for mine ventilation usage because the effect of air on the saturated water vapor was disregarded. Presented here are the newest and most accurate currently available tables from the National Bureau of Standards (NBS). Also included are: (1) a formula for correcting the saturated water vapor pressure for temperature and altitude. (2) a formula for computing unsaturated water vapor pressure, and (3) a formula for air density. Because Systeme International (SI) units are used in the formulas, conversions are given from U. S. conventional units to SI units. The intent of this paper is to show by means of six steps the accurate calculation of mine air density for use on modern computers.

Jan 1, 1989

By Mark C. Williams, Shunsuke Managi, Noriko Hikosaka Behling

Particle processing is a key to using solid particles in fuel cell applications. Selectivity with regard to reactivity, impurities, etc. is an important feature and the treatment of particle surfaces could greatly impact the performance of direct carbon fuel cells. Solid fuel particles will become increasingly important in the future. Present energy conversion systems for solid fuels are too inefficient. New energy conversion systems for solid fuels with higher energy conversion efficiencies are possible. Fuel cell technology is a key technology in these new conversion systems. The direct carbon fuel cell (DCFC) operates on carbon particles obtained from a variety of solid fuel feedstocks. The DCFC is the only fuel cell designed to directly oxidize carbon particles in a special anode chamber. The particles are generally graphite structure with high purity. The electrolyte used is the high temperature solid oxide, molten carbonate, or hydroxide electrolyte. Since a pure stream of CO2 is produced, the stream can easily be sequestered and disposed. Pure carbon dioxide produced as a by-product would also have a market in many industries. A well-defined technology roadmap identifying key research and development (R&D) issues is necessary to provide a framework for the development of these systems and to prevent entrenchment in inherently inefficient technologies. This review paper describes the direct carbon fuel cell and its system, how it works, the developmental status, the characteristics of the carbon particles needed, and the research and development issues for the technology

By J. R. Patts, L. D. Patts, S. J. Janisko, T. Barone

"Controlling float coal dust in underground coal mines before dispersal into the general airstream can reduce the risk of mine explosions while potentially achieving a more efficient and effective use of rock dust. A prototype, flooded-bed scrubber was evaluated for float coal dust control in the return of a continuous miner section. The scrubber was installed in line between the ventilation tubing and an exhausting auxiliary fan. Airborne and deposited dust mass measurements were collected over a period of three days at set distances from the fan exhaust to assess the changes in float coal dust levels in the return due to the operation of the scrubber. Mass-based measurements were collected on a per-cut basis and were normalized per foot of advance by the continuous miner. Results show that average float coal dust levels measured under baseline conditions were reduced by over 91% when operating the scrubber. INTRODUCTION In 2012, underground mining in the United States produced over 342 million tons of coal [EIA 2013]. During the cutting, crushing, and transport of this coal, dust is generated and can be entrained in the air ventilating the mine. Title 30 Code of Federal Regulations Part 75.400-1 (30 CFR§ 75.400-1) defines float coal dust as particles of coal that can pass a No. 200 sieve. These coal particles can be carried by the ventilating air into return entries before settling onto mine surfaces [NIOSH 2006]. If this float coal dust becomes re-entrained into the airstream, it can propagate an explosion throughout mine workings [Harris et al. 2010]. Application of rock dust in underground coal mines is required by Federal regulation as a means of preventing the propagation of explosions by float coal dust. In order to meet Title 30 Code of Federal Regulations Part 75.403 (30 CFR § 75.403), 80% incombustible content must be maintained in the composition of dust deposited in mine entries [76 Fed. Reg. 35968 (2011)]. This fraction of incombustible content is increased if elevated levels of methane are present. In order to maintain the required incombustible content, frequent or constant application of rock dust is undertaken by mine operators. Title 30 Code of Federal Regulations Part 75.2 (30 CFR § 75.2) defines the properties of the rock dust that must be used by mine operators."

Jan 1, 2015

By B. Stewart

Recent ore pass failures have underlined the need for improved designs, standards, structural monitoring methods, and better hang up prevention and removal techniques. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) are investigating methods to improve safety during transport of ore in ore passes. Design criteria and hang-up prevention and remediation strategies involve studies of the effects of static and dynamic ore and waste rock loads on chutes, walls, gates, and support structures. Particle flow analysis methods were used to simulate the response of various ore pass designs to a wide range of ore loading conditions. A full-scale mock-up of actual ore pass and chute assemblies was duplicated and tested for load response. Data from a particle flow code and the mock-ups were com-pared. Loads on an active ore pass chute were measured.

Jan 1, 1998

By Samuel S. Adams

The Grants uranium region of northwest New Mexico is the largest uranium district in the United States (approximately 50% of U.S. production plus reserves) and one of the largest In the world, with approximately 900 million pounds U308 production plus reserves. Deposits of the region are unusual among sandstone deposits for their high content of epigenetic carbonaceous material, generally interpreted but not proved to be of humic origin--that is, co-extensive with uranium in the primary deposits. Virtually all production in the region has been from the Jackpile Sandstone and Westwater Canyon Member of the Jurassic Morrison Formation. The tabular uranium deposits contain, in addition to humate and uranium, significant authigenic phyllosilicates, quartz overgrowths, humate-replaced detrital silicates, and a trace-metal assemblage typical of other sandstone uranium deposit types. Surrounding the deposits in the two sandstone units of the Morrison Formation is an alteration zone within which iron leaching has altered detrital ilmenite-magnetite to residual masses of titanium oxides. Feldspar alteration is locally present within this zone, below deposits in the Jackpile Sandstone, and above those in the Westwater Canyon Member. The feldspar alteration increases in inten¬sity toward the Brushy Basin Member which separates the two sandstone units, ranging from partial replacement to replacement and dissolution of plagioclase and sanidine. Spatial relations among the epigenetic humate, authigenic silicates, and the broad alteration zones that extend from the Brushy Basin Member to and including the uranium deposits suggest that (a) the organic material was involved in the unusual silicate alteration, transport, and authigenesis, and (b) that the humates originated in shales of the Brushy Basin Member. Stratigraphic relations among the Brushy Basin Member and the overlying Jackpile Sandstone and underlying Westwater Canyon Member suggest [in turn] that there was continuous, interfingering deposition controlled in part by contemporaneous basement subsidence along northwest- and northeast-trending zones. Following minor erosion of upper Jackpile Sandstone and deposition of basal organic-rich Cretaceous sediments, the silicates of the Jackpile Sandstone were once again altered by organic-bearing fluids, this time permeating down from Cretaceous sediments and partly obliterated ore-stage alteration.

Jan 1, 2013

By R. R. Guzman

In this study, the "Mine Project Risk Management" methodology, MPRM (Botin et al. 2011), has been applied to characterize the sources of uncertainty and to quantify risk in the mining engineering stages of Block Caving mining method. As the result, rock mass caveability and ore fragmentation were identified as the two most relevant parameters of this process and a methodological model has been developed to quantify the risk associated to each of these two parameters. Furthermore, the applicability of the proposed model has been validated using as a case study the Chuquicamata Underground Mine Project in Chile.

Feb 23, 2014

By Haydn H. Murray

In 1967 a large kaolin deposit was discovered on the Jari River, a tributary of the Amazon, in the territory of Amapa in Brazil. The kaolin occurs in the Barreiras Series of Pliocene age and is part of the Belterra Clay. The kaolin was drilled and tested, and today a modern processing plant is producing over 150,000 tons per year of high quality paper coating clay. Some of the problems associated with the mine development, processing, personnel, and marketing of this remote kaolin deposit are discussed. The mineralogy and physical properties of the Jari kaolin deposit are also described.

Jan 1, 1981

By Duah Philip, Awuah-Offei Kwame

Regulatory pressure to mitigate the cement industry’s environmental impact has intensified recently, spurring innovation in low-carbon cement technologies. In the United States, cement production, consumption, and carbon emissions are accelerating. Despite this trend, the adoption of environmentally friendly dry clinker production technology with combined preheater-precalciner systems has surged from 53.3% in 2002 to 88.5% in 2019. Concurrently, reliance on wet technologies, known for their higher environmental impact, has dropped from 16.5% to 0.6% within the same period. This paper presents the results of our comprehensive study, utilizing over 100 years of industry data, to analyze these technological shifts and their environmental implications.

Feb 1, 2025

By RICKARD HANSEN

With vehicles frequently found in underground mines and tyres being a major fuel item, the risk of tyre fires will be severe underground. This study presents an in-depth analysis of tyre fires on mining vehicles to increase the knowledge of the risk, applying data from full-scale fire experiments and CFD simulations. It was found that the wheelhouse of the loader caused an increase in the flame tilt angle of approximately 10%, decreasing the flame impingement and heat flux downstream. The flame temperature of the drilling rig tyre was found to be approximately 7% higher than the loader tyre, increasing the risk of igniting adjacent fuel items. The construction of the wheelhouse/mudguard will contribute to a longer flame length by creating a fuel-rich environment. The CFD simulations predicted higher flame tilt angles for the drilling rig case for higher flow velocities, indicating the influence of a varying wheelhouse/mudguard construction and tyre geometry on the flame tilt angle. The construction of the loader resulted in a flow behaviour, where the short distance to the front mudguard/tyre and the separation of flow directly downstream of the protruding construction led to fire gases being steered past the front mudguard/tyre. In the drilling rig case, the longer distance to the front mudguard/tyre led to fire gases being directed towards the body of the vehicle after passing the area with flow separation. An increased knowledge of the tyre fire risk on mining vehicles and mitigating measures would improve the fire safety in underground mines.

Feb 10, 2022

By S. T. Hall

The authors have previously described a method of enhancing the magnetic susceptibility of pyrite by a mild alkaline oxidative pressure leach (Hall et al, 1985). This finding was successfully applied to enhance the magnetic desulfurization of an Eastern Canadian coal (Hall and Finch, 1984). This paper reports on enhancement of the magnetic susceptibilities of iron-containing sulfides (arsenopyrite, chalcopyrite and marcasite) upon similar treatment. It also explores the application of this pretreatment in the magnetic separation of fine sulfides from oxides and other sulfide minerals. In the latter case galvanic interference effects have a serious impact on the potential use of this method.

Jan 1, 1985

By Nicola Beltrandi, Andrea Pigorini, Holad Mohamed Dahir, Ezio Pedone

"Genoa is a very distinctive city located between mountains and the sea and infrastructural upgrading works often have to deal with the intersection of existing infrastructures. This is the case for the new railway tunnel construction between the stations of Brignole and Principe which under-cross two existing double-track tunnels in operation. The latter have been constructed with masonry bricks and the vertical distance between old and new tunnels is approximately 1m. Due to rock characteristics and the urban environment, stability and vibrations control are the main issues. Consolidation work with the fore-poling method and a specific sequence of excavation, primary lining and final lining support have been designed to assure stability and settlement control. A hard rock road-header has been used to assure vibration control. Finally, a real time monitoring has been implemented. The article presents monitoring and back-analysis results of the under-crossing of the existing tunnels. GENERAL LAYOUT OF WORKS The Genoa railway junction constitutes an integral part of the Ventimiglia-Genoa-Novara-Milan railway line route and it is included amongst the railway systems of the Tyrrhenian-Northern European multi-modal corridor (corridor of the two seas or corridor VII Genoa-Rotterdam). The main aims of the project concern the upgrading of the existing lines and the separation of the long-distance passenger and freight traffic flows from those of a regional and metropolitan type. The project includes: •,Completion of the connection with the port of Genoa Voltri and the Italy-France coastal route. •,Interconnection with the future Terzo Valico dei Giovi mountain pass route towards Milan. •,Upgrading of the Genoa Voltri – Genoa Brignole main line to four/six tracks. Rearrangement of the systems at the Genoa Voltri, Genoa Sampierdarena and Genoa Brignole Stations, reorganisation of the services in the Genoa Terralba area and interchangeability with the metropolitan system complete the design activities. The contract which includes civil and technology works is divided into four construction lots (ref. Figure 1):"

Jan 1, 2016

By Ronald L. Wiegel

In a mineral processing plant there are a number of routine decisions which are based at least in part on the plant's metallurgical performance. Among these are those related to: 1) equipment functioning properly 2) suitable operating conditions 3) reagents achieving desired results 4} determining operating response to changes in ore 5) defining circuits offering potential for improvement A step beyond the routine, are the periodic management evaluations of operating supervision and technical assistance, which are based largely on profit -a direct function of are availability, metallurgical performance and operating costs. The "yardstick", excuse me -"meterstick", by which performance is best measured is the plant metallurgical balance, which tells not only what was produced but how it was produced. Since this metallurgical balance is directly related to both plant profits and individual rewards, it is only reasonable to make that "meterstick" as precise as humanly possible.

Jan 1, 1978

By Richard A. Thomas, III JAMES H. ROWLAND, Liming Yuan

This paper presents the results of large-scale fire experiments on evaluating the performances of carbon monoxide (CO) and smoke sensors at low ventilation velocities. Experiments using three different combustibles — conveyor belt, coal and diesel fuel — were conducted in the experimental mine at the U.S. National Institute for Occupational Safety and Health (NIOSH) Bruceton Research Facility. A total of eight sensor stations were located downstream of the fire with each station containing sensors for CO, smoke, carbon dioxide (CO2 ), oxygen (O2 ), humidity, barometric pressure and temperature, as well as two airflow sensors. The airflow velocity ranged from 0.22 to 0.26 m/s (44 to 51 fpm) in the tests. The response times were recorded for the CO and smoke sensors at each sensor station when smoke and gaseous products of combustion from each burning combustible reached the station. The response times of the CO sensors were used to determine the appropriate sensor spacing in the belt entry with a low air velocity. The performance of the smoke sensor was found to be affected by the high humidity in the experiments. The results on proper selection of sensors and the determination of sensor spacing at a low ventilation velocity can be helpful for ensuring sufficient early fire warning for underground workers, thereby improving the health and safety of miners.

By Yuting Xue

Classification of rock and coal is one preliminary problem for fully automated or intelligent mining. It assists in automated rib stability analysis and enables the shearer to adjust the drums without human intervention. This paper studies the classification of rock from coal on rib images using machine learning techniques. A database of rock and coal images was created by filtering photographs taken by NIOSH researchers during site visits. Machine learning was conducted on patches, smaller images randomly extracted from each rock or coal image. After training, the classifier was validated with the testing dataset and achieved an accuracy score of 0.9.

Jan 13, 2022

By S. G. Malghan

Flotation is the primary method for copper minerals separation from porphyry ores. The need to process difficult-to-float porphyry copper ores presents challenges to engineers and scientists in several areas. This paper is concerned with summarizing generalized problems faced in the processing of porphyry ores and treatment methods to overcome the specific problems. Though some of the problems are interrelated the problems have been classified into three broad catagories. The case studies of some of the successful applications of innovative methods to solve problems related to ore mineralogy, metallurgical aspects of ore treatment and process variables show that quite often the problems are solvable by a judicious choice of flotation variables.

Jan 1, 1984

By K. H. McDaniel

An interactive mine ventilation simulation software program (WIPPVENT) was developed at the Waste Isolation Pilot Plant (WIPP). The WIPP is a U.S. Department of Energy (DOE) research and development project located near Carlsbad, New Mexico. The facility is designed to provide a permanent, safe underground disposal of U.S. defense generated transuranic waste in bedded salt. In addition to its regular functions, the underground ventilation system is engineered to prevent the uncontrolled spread of radioactive materials in the unlikely event of a release. To enhance the operability system, Westinghouse Electric Corporation has developed an interactive mine ventilation simulation software program (WIPPVENT). While WIPPVENT includes most of the functions of the commercially available simulation program VNETPC (copyright © 1991 Mine Ventilation Services, Inc.), the user interface has been completely rewritten as a Windows ® application and screen graphics have been added. WIPPVENT is designed to interact with the WIPP ventilation monitoring systems through the site wide Central Monitoring System.

Jan 1, 1996

By Ron Robinson

Booster fans have been in regular use in British coal mines since the first half of this century, but a large increase in their use did not take place until after the Nationalization of coal mines in 1947. From that time the need was identified to improve standards of ventilation in general and mining engineers specializing in ventilation were appointed at all levels in the mining industry. A comprehensive approach to ventilation surveys and planning, together with the realisation of the benefits of booster fans, led to their more rapid introduction. Many coal mines in the U.K. are at moderate depth and have virgin strata temperatures of 30°C or less. The ability to control climatic conditions by increased ventilation rather than resort to cooling systems has led to the introduction of booster fans and recirculation systems in these mines. Large makes of methane and high levels of coal dust production due to increased mechanization have also required enhanced ventilation standards. This paper deals with the reasons for selecting booster fans and the specific safety considerations involved in their use. Numbers, types and sizes of booster fans in the U.K. are outlined, together with notes on installation and performance. Remote monitoring and control from the surface is dealt with, and current legislation. The evolution of controlled recirculation is also covered starting with auxiliary fan systems in 1970 and leading to very large district schemes in the late 1980s. The research at Newcastle upon Tyne University and other establishments in the climatic conditions associated with recirculation is summarised and its use in assisting existing and proposed conventional and recirculation systems is indicated.

Jan 1, 1989