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By Fred N. Kissell

The new MSHA diesel rules have stone mine operators looking hard at pos¬sible upgrades to their ventilation systems. There are existing methods to reduce diesel engine emissions (MSHA, 2001)(Head, 2001b),but many operators will decide that a ventilation upgrade is necessary is well. NIOSH hay several stone mine ventilation projects underway, but in the meantime a good information resource is the work done by the U.S. Bureau of Mines in the 70's and 80's on ventilation for oil shale mines. The Bureau conducted this research because oil shale mines were projected to be gassy and would, therefore, require a lot of ventilation air. The focus of this oil shale work was on the use of jet tans for lace area ventilation, and on stoppings that would he low Lost and leak-tight. The work also considered changes in mine design to reduce the number and size of stoppings. The findings are still applica¬ble to stone mines.

Jan 1, 2002

Jan 1, 1922

Jan 1, 1922

By E. S. Moore

In the townships of Genoa and Marion, Subdury Mining Division, Ontario, there is a group of twenty-three mining claims known as the Jefferson claims. They are controlled by the Jefferson Mining Corporation and they were staked in 1908 by W. E. Smith, formerly of Sudbury, Ontario, and now of Smith & Reitz, a law firm of Minneapolis, Minnesota. These claims were staked for iron ore and in 1910 about 4000 feet of diamond-drilling was done on them. During the drilling operations galena and sphalerite ~were found in the iron formation in cores from holes, Nos. 2 and 3, claim W. D. 717, Genoa township. This discovery lead to a search for galena and sphalerite in the vicinity and a streak of rock containing these minerals was found in the iron formation a short distance to the east of. the drill holes. A shaft was sunk on this outcrop in 1912 to a depth of 8 feet and bottomed in an attractive lens of galena. Stripping revealed other small exposures of galena and sphalerite in the iron formation.

Jan 1, 1926

By JOHN A. MALONEY

AS noted in the February issue of MINING AND METALLURGY, an advisory committee to the Museum of Science and Industry of Chicago was authorized by the Institute's Board of Directors, with W. R. Wright of Chicago, former Director of the Institute, as chairman. Since that time the committee has been undergoing organization, and held its initial meeting at the Museum offices in Chicago on April 11 and 12. Functioning as consultants to the Geology and Mineral Industries branch of this new institution, the advisory committee is aiding in building an exhibit which will tell the story of geology, mining, and metallurgy to millions of visitors a year. Although patterned to some extent

Jan 1, 1932

By M. Somerville

In 1989 CSIRO Minerals initiated investigations into continuous converting of copper matte into low sulphur blister in Sirosmelt type reactors. Following the successful piloting of this processing route, some effort was directed towards a single stage copper making process where copper metal is made in one step from concentrate. The aim of the project is to develop a continuous process, which offers considerable environmental and economic benefits over conventional copper making processes, which use Pierce-Smith converters. In the selection of the optimum flowsheet a number of slag treatment options have been considered and tested. These unit operations include: leaching and electrowinning, flotation-leaching-electrowinning and flotation with recycling of recovered copper through the smelting vessel. In this paper the suitability of these process options are evaluated using the available information and recently measured copper recoveries from our testwork at CSIRO. The operating and capital costs of the various options have been estimated using Aspen Plus simulation procedures. The most attractive flowsheet in terms of capital and operating costs is the treatment of slag using mineral processing techniques and the recycle of a copper slag concentrate to the smelting vessel. It has been found that the chemistry of the slag being treated has a large bearing on the recovery of copper in flotation and hence on the economics of the process.

Jan 1, 1999

By Chen Feng

Compared to widespread successful deployment of robotic manipulators for repetitive and hazardous tasks in related industries such as manufacturing, the construction industry has achieved relatively limited benefits from robotics and soft automation. Unlike manufacturing, where robotic solutions benefit from the structured layout of the environment (e.g., factory assembly line), construction robots face unique challenges that arise from the rugged, dynamic, and unstructured environment of the work site, as well as the uncertainty and evolving sequence of occurring on-site events. This challenges any intended construction robots to not only replicate basic human motion, but also be capable of sensing and adapting to environmental changes, and making decisions based on the evolving state of the environment. Building upon recent advancements in robotic mapping, computer vision, and object recognition, the authors propose to introduce autonomous behavior at the basic task level for on-site construction robots to address these challenges in a flexible and extensible manner. This paper reports the outcome of the first phase of this research - a structured methodology for improved design and development of basic task automations - and focuses on algorithms developed for mobile robot navigation and relative pose estimation. The algorithms are implemented on a prototype mobile robotic platform, and evaluated in several experimental scenarios.

Aug 1, 2013

By K. S. Raja, B. Pesic, S. Kshetri

"We investigated the electrochemical corrosion behavior of commercial permanent magnetic material (NdFeB alloy) in 0.1 M NaH2PO4 solution (pH:4.75) containing 0 – 1000 ppm of chloride at room temperature (298 K). The material was evaluated in magnetized and demagnetized condition with different surface preparations such as: Ni-Cu-Ni coated, uncoated (bare), and anodized (in fluoride containing ethylene glycol at 60 V for 15 minutes to form a thick nanoporous oxide surface). The nickel coated magnetic sample showed reasonable pitting corrosion resistance up to 100 ppm chloride addition. The uncoated samples showed passivity in chloride free phosphate solution. Chloride additions caused pitting and the pitting protection potential was equal to the corrosion potential with 100 ppm chloride addition. Demagnetization did not alter the electrochemical polarization. However, the passive film formed on the magnetic sample showed higher charge carrier density than the film formed on the demagnetized sample. INTRODUCTIONSintered NdFeB permanent magnets exhibit excellent magnetic properties such as large energy product [(BH)max > 450 kJ/m3], high saturation magnetization (1.6 Tesla), and high coercivity (1.2 – 2.08 x 106 A/m) (Sugimoto, 2011). However, the NdFeB magnets are prone to corrosion attack because of the presence of Nd-rich intermetallic phases, such as Nd4Fe (Jurczyk & Jakubowicz, 2000). Nd-rich and B-rich intermetallic phases are distributed in a matrix of Nd2Fe14B tetragonal ferromagnetic compound in a permanent magnet. Generally, several types of Nd-rich phases are present in the magnet with Fe:Nd ratios ranging from 1:1.2 to 1:7. The volume fractions of Nd-rich and B-rich (Nd1+xFe4B4 type) phases are about 10% and 7% respectively (Li, Ma, Li, & Wang, 2011) . Among these intermetallic phases, Nd-rich phase has the most active electrochemical potential. Therefore, dissolution of this phase occurs in preference to other phases by galvanic corrosion when exposed to moisture. Since Nd-rich phases are present at the grain boundaries of the Nd2Fe14B matrix, corrosion leads to disintegration of the magnet."

Jan 1, 2012

By Devan Naik, Matthew Stokes, Andy Nigro

This paper describes the surgical removal of a 24 ft dia. Slurry Shield TBM entombed beneath one of the country’s busiest commuter rail interlockings, the Harold Interlocking in Queens, NY, and the construction of the interface to a cut/cover tunnel which extended the mined tunnel section. A sophisticated SOE was built around the TBM to support active track loads within 8ft. of the excavation. Once the TBM head and guts were removed, a full round CIP lining was installed connecting the existing precast tunnel liner to the C/C tunnel under construction. All this construction was done on a narrow island of land without road access nestled between 7 mainline LIRR/Amtrak rail lines.

Jun 13, 2021

By E. Watkins, R. Kimutis, H. Dougherty

Gas wells have often intersected mining resources, but unconventional shale well drilling has more recently challenged mines to balance the risk of interaction due to higher pressures and larger quantities of gas. Full extraction mining, such as the longwall method, induces ground movement that may influence the casings if wells are drilled within the mining area. The possibility of a casing shear would lead to the risk of unplanned gas migration into the mine. This has the potential to quickly overcome the ventilation system and reach the explosive range which, if ignited, can have catastrophic consequences on the health and safety of underground workers. The utilization of network software to model mine ventilation is a common practice in the mining industry and can assist with a well breach scenario. This work focuses on a well breach in between two longwall panels after second panel mining with gas entering primarily through the gobs of the adjacent longwall panels. Applying the network software Ventsim, a gob zone and ventilation network were created to better understand the distribution of gas within the mine and the limitations and effectiveness of a ventilation system. The model shows both a transient flow simulation and steady state concentrations throughout the mine ventilation system. Using a standard Pittsburgh coal seam longwall ventilation scheme, we find that the system can dilute a significant inflow of up to 700 cfm of methane.

Mar 2, 2022

By James Pegues, Ron Johnson

A solar facility in the western United States was sited within the footprint of a dry lakebed, or playa, with construction completed in 2016. Conventional geotechnical studies were performed prior to design and no unusual conditions or features were noted. The facility has unexpectedly experienced several episodes of ground fissure development after moderate to heavy rainfall events, the first somewhat isolated event occurring shortly after the facility was placed into service. Subsequent fissures developed in 2017 and 2022, with severity of the fissures and their impacts increasing each time, with the final episode resulting in fissure depths on the order of 30 feet. Initial fissure events primarily impacted site access. The 2022 event impacted site access, infrastructure, and solar array pile foundations. Various remedial measures were implemented to address the fissures, including CLSM backfill (2016) and the injection of epoxy-based urethane foam (2017). Prior to developing repairs for the 2022 event, additional studies were performed to evaluate the fissure formation including geophysical exploration, review of historical topography and aerial photographs, hydrologic modeling, and research. Mitigation of the 2022 feature included backfilling with granular backfill and sand-cement slurry and constructing surface water conveyance features to direct surface runoff away from the fissure.

Oct 7, 2024

By G M. Taylor

The application of high technology to monitor and control fire life safety, critical functionality in tunnels and underground spaces generally has progressed at an ever accelerating rate over the past decade. Today these systems comprise some of the most complex and little understood aspects of the tunnel/underground facility construction industry, with this area being perceived as high risk comprising impenetrably complex ‘black box’ technology covered in blinking LEDs. This paper will seek to explode some urban myths and common misconceptions associated with such systems, providing its intended audience with a review of what all this technology comprises and where the real risks lie in its delivery lie.The author contends (and looks to support such contention via this paper) that by applying baseline project and risk management processes to the procurement of this widely misunderstood black box technology, the quality of the final outcome can be much improved, driving innovation, reducing both cost and significantly mitigating delivery risk.CITATION:Taylor, G M, 2014. Procuring control and intelligent traffic systems for major new build projects – avoiding pitfalls and maximising value, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 113–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Hamid Maleki

A new failure criteria is proposed for assessment of roof stability in underground sedimentary rocks. Unlike other stability assessment techniques, this method is simple and practical, having improved mine safety and productivity in several mines. It is shown that roof movements accelerate to a critical rate prior to actual roof collapse. Critical rates vary between 0.025 inches per day to 0.2 inches per minute depending on rock mass - pillar mechanical properties. Specific critical rates are determined for three rock mass - pillar categories which are common to mining in sedimentary rocks. Time-to-caving varies from one minute to ten days on rock structural controls and type of primary support utilized.

Jan 1, 1990

Provide an economic alternative to drill-blast excavation with the same ability to excavate openings of varied orientation, shape, and size. Approach Develop an efficient, adaptable, mechanical excavation machine that produces unconfined tensile failure in rock. How It Works A drill-split fragmentation machine that combines a drill and a unique splitter has been developed. The drill and splitter are mounted on a carriage that positions the splitter in a hole immediately after it is made by the drill. The splitter creates force loads that cause the rock to fragment, and the process is repeated for excavation. The unique splitter applies both radial and axial loads to the rock mass, which produces an excavation action comparable to pulling a plug. This excavation action distinguishes the radial-axial splitter from typical demolition splitters, which require a free surface parallel to the axis of the splitter toward which to break rock.

Jan 1, 1989

Jan 1, 1947

By Valentin R. Garfias

The world's production of petroleum during 1926 is estimated at 1,096,000,000 bbl., an increase of about 29,000,000 from that of 1925 and somewhat larger than the average during the last 4 years, which is about 1,049,000,000 bbl. The daily average during the year may be estimated at 3,000,000 bbl. of which the United States produced 2,123,000 and other countries 877,000. The outstanding developments during the year have been the decline of the Mexican fields, the counterbalancing of this decline by the increase in Venezuelan and Russian production, and increases in Roumania and Colombia. During 1926 the United States, Mexico and Russia retained their relative positions as the three leading producers, while Venezuela probably outranked Persia for fourth place, Roumania passed Dutch East Indies for sixth, and Colombia moved from sixteenth to the eleventh position. It further appears that should present conditions develop normally throughout 1927, it is not improbable that Mexico will be outranked by Russia as the second oil-producing country and that the increased yield of Colombia will place this country in the eighth or ninth position, and ahead of India. The United States and Mexico should produce in 1926 about 79 per cent. of the world's total and the aggregate of the seven leading countries should be close to 95 per cent. of the total. It is interesting to note that about 85 per cent. of the total comes from fields on the American continent, the United States accounting for about 71 per cent., and Spanish-American countries and Trinidad for 13 per cent. Production of countries other than the United States and Mexico has gradually increased during the last four years and now represents about 21 per cent. of the total. The United States easily retains its long standing leadership with a total yield of 775,000,000 bbl., or an average daily yield of 2,123,000, representing about 71 per cent. of the total, which is about equal to that of the previous year. An increase in production of about 11,000,000 bbl. is indicated by the statistics so far available. It will be noted that the American production in the last 4 years has averaged about 746,000,000 bbl. yearly and that this uniformity, as well as the marked increases

Jan 1, 1927

By AIME AIME

NO ADEQUATE salary scale, at the present time, can ignore the increase in the cost of commodities 'during the last few years or- afford to assume that this increase is merely temporary. A study of the change in prices and wages during and after the Civil War is of interest in connection with changes that have taken place from 1913 to 1919. The curves on the accompanying figure, based on reports of the War Industries Board and Department of Labor, show these changes. During the Civil War retail prices rose to 164,2 per cent. of the prices of 1860, during the next 8' or 10 years. It is interesting to note that the rise in wages during the Civil War was almost simultaneous with the rise in the prices of commodities. During the World, War, the rise in wages has lagged about a year behind the rise in prices. Furthermore, in the period immediately, following the Civil War, wages continued to rise after prices started to fall, The present price level is not considered merely temporary by such of our Government agencies as the Department of Labor and the Federal Reserve Board or by such economists as Irving Fisher' and J. S. Holden.2 Sub-

Jan 1, 1920

By T. A. Laser

"INTRODUCTION A positive workplace environmental, health, and safety (EHS) culture affords organizations and corporations many benefits, including increased trust and employee morale, sustainable EHS performance improvements, and reliable productivity and profit margin growth. Unfortunately, many leaders and EHS professionals struggle daily to achieve and maintain positive workplace cultures and consistent business results. While lack of management support, corporate or employee buy-in, resources, and time are common factors that conflict with an EHS culture and safe work behaviors and processes, there are many other actions that threaten the positive attributes of an organization’s culture. Often these culture killers are not recognized, or worse yet, ignored because they are considered taboo. For example, voicing observations or questioning long-held management practices or process that were initially designed to promote EHS values, but no longer do so. Unfortunately, this could be viewed as challenging authority, not being a team player or even not valuing EHS. And for those that speak up, the potential for negative consequences can be real impediments to positive change. Having an open mind, constantly striving to identify culture killers, and putting forth the effort to eliminate them are the first steps to begin reaping the benefits of having a sound workplace culture. This paper helps readers to: • Recognize culture killers that negatively impact fostering and maintaining sustainable EHS cultures in the workplace. • Understand how to prevent, avoid, and respond to culture killers, before they wreak havoc in your organization. • Assess EHS culture strength, and implement plans to continuously improve it. The desire to draw boundaries around concepts, put things into boxes, and nail down requirements for something that is virtually impossible to solidify for any length of time is quite fascinating! These desires can pose challenges when trying to define what the perfect EHS culture should look like. The very act of trying to define our culture tends to create silos, and these silos, in turn, can become “culture killers”. The following is one of the most common culture killers. UNBALANCED ORGANIZATIONS TRIGGER CULTURE KILLERS Unbalanced organizations occur when an organization’s constantly shifting focus forces other important needs to take a back seat--until the focus changes again. This balancing act can be detrimental and lead to catastrophic results including low morale, lack of trust, employee dissatisfaction, high turnover, increased incidents, poor profit margins, loss of market share, and ultimately into organization-wide failure."

Jan 1, 2018

By S Juras

The terms measured resources and proven reserves denote the highest level of estimation confidence in all of the major classification schemes. But what do they really bring to today’s project or mine with respect to production planning and expectations? Initial reserve declaration does not need measured resources, just indicated resources. Economic viability of a project is assessed on total reserves with nary a bonus for the amount of proven reserves. Production plans are based on grade and tonnage goals that may only coincidently correspond to proven reserves. So are the measured and proven categories still relevant? Historically, and almost exclusively in underground mines, companies only allowed mining in areas of proven reserves. Some companies still follow that philosophy. But many others will mine a mixture of probable and proven reserves without hesitation. Also what of the undeveloped project in a new district – what is to be made of their declared measured resources and proven reserves? Measured resources are commonly set either by some type of proximity to data scheme or a matter of ‘feel’ based on the qualified person’s experience. The parameters for reserve conversion focus on the project as a whole and then a portion becomes classified as proven reserves almost solely based on whether the resource category is measured. So should the mining industry continue to use these categories of resource and reserve classification? This paper will present arguments about making these categories once again more relevant. A more disciplined usage of these categories may re-introduce their relevancy in public disclosures of resources and reserves. As well a more consistent usage in operations may lead to increased confidence in managing production targets and costs.

Aug 22, 2011

By Philip J. Bangerter, Chris Twigge-Molecey

Design for safety is critical to metallurgical plants, due to the inherently dangerous nature of their processes. Two significant areas of concern are: 1. preventing catastrophic process failures that cause damage or injury; and 2. operational safety that directly affects those working in or living near the plant. Process safety involves human behaviour, but the designer can eliminate or control hazards by engineering approaches, and control impacts through the design of the operating procedures. The tools available to guide safe facility design include bowtie analysis, hazard analysis, and hazard and operability studies. Clean plant design principles can guide the design process to address in-plant occupational health and safety issues. Auditing and review is a key part of the overall design process.

Jan 1, 2015