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Jan 1, 1885

By Humphrey Dean

"Canadian mining companies now operate numerous Koepe-type friction hoists in a variety of different shafts, most of which have a depth in excess of 3,000 feet. Rope performance reliability is an absolutely essential ingredient of most installations and, for this to be provided, a more comprehensive understanding of rope reactions to applied stresses is required.It is the intent of this paper to illustrate for the operators the importance of the critical stresses encountered and to provide a maintenance program designed to circumvent potential difficulties."

Jan 1, 1970

By Jay F. Colinet

Coal workers’ pneumoconiosis (CWP), commonly known as black lung, is caused by the inhalation of respirable coal mine dust and is a disabling and potentially fatal lung disease with no cure. Historically, CWP has taken a tremendous human and financial toll in the US coal mining industry. Recent health surveillance data indicates that CWP continues to occur at elevated levels. Respirable coal dust exposure must be controlled to prevent the development of CWP. The Pittsburgh Mining Research Division of the National Institute for Occupational Safety and Health (NIOSH) conducts laboratory and mine-site research to identify control technologies that can be used to successfully reduce respirable dust levels. Various technologies, using multiple methods of control, can be applied in order to reduce dust levels. An overview ofCWP’s impact and a general methodology for controlling respirable dust in underground coal mines are discussed in this paper.

Jul 30, 2020

By Enzo Palumbo, Joël P. T. Kapusta, François Larouche

In light of the rapid deployment of bottom blowing smelting in China over the last ten years, one has to wonder why it has taken the copper industry so long to adopt ultra-high oxygen enrichment via Savard-Lee type injectors. As early as 1976, Kellogg and Henderson suggested, in their landmark paper on energy usage in the copper industry, that ‘maximum use of oxygen enrichment of process air’ was one of seven ‘energy saving features’ for copper matte smelting and converting. Yet today, shrouded injection and high oxygen enrichment has not been implemented in copper bath smelting outside China and Vietnam. In this paper, the authors explore the reasons why bath smelting processes such as the Noranda Reactor and the Teniente Converter still operate around 40% oxygen enrichment, while the bottom blowing SKS/BBS process typically runs at 65 to 75% oxygen, with all three processes producing white metal. Are there fundamental metallurgical explanations for this striking difference beyond the long-standing skepticism towards high oxygen shrouded injection and its perceived high implementation cost?

Jan 1, 2015

By Juel H. Stears

Research was done to determine if a hydraulically operated penetrometer developed by the Bureau of Mines could be used to estimate the roof-bolt anchorage capacity of mine roof rock. Tests were conducted both in the laboratory using cement cylinders and underground in shale rock. Hardness readings were measured by the penetrometer around the periphery of the bolt holes at the anchorage horizon. Roof bolts Nere then installed and subjected to an anchorage test. The results showed that the penetrometer readings could be used to determine the optimum stratum for roof-bolt anchorage but could not be used to make an accurate estimate of the anchorage capacity.

Jan 1, 1965

By C. Eddine

"Can we use data to make communication effective? How does one successfully tackle the challenge of solving cultural differences and harmonizing the needs of diverse stakeholders while developing and maintaining a strong and reliable corporate image? Is it possible to achieve better engagement and minimizing risks with data? This paper aims to explore human rights and business procedures, the promotion of shared prosperity in a sustainable manner and the use of metrics to guide decision-making process. Among the topics examined are: • the significance of stakeholder engagement in community development projects; • the use of grievance mechanisms to give a voice to First Nations and communities / populations in vulnerable positions (including children and elders); • the benefits of configuring and implementing a feedback system in partnership with the communities. This research is a preliminary initiative and has limitations on the extent of the material used. The author acknowledges there is a vast amount of work and publications available on this subject, as well, as a variety of examples that have not been included. The intention is to keep developing this research to assess and expand how data can be used to minimize risks and improve engagement, in addition to inspire others to continue advancing this topic. Natural resources consumption is a reality that will not disappear in a foreseeable future. Several developments and operations are located in remote areas where communities in vulnerable situation and Indigenous Peoples live. Feedback systems are being ratified as a tool to help tackling the challenges of harmonizing cultural differences and fulfilling the needs of diverse stakeholders. Integrating social, environmental, and economic values plays an imperative purpose in preserving a productive and trustworthy relationship with stakeholders. Positioning social standards next to environmental and economic principles shows inclusiveness and firm intention of integration. We add value to a positive image of our industry by embracing responsibility for corporate actions and promoting their beneficial impact on the environment. The social context within communities, groups and organizations is dynamic and presents new challenges as connections evolve. There are wildly diverse expectations which one may need to address during exploration, construction and operating phases. Disagreements are an inevitable consequence of interactions due to the different needs and requirements of the parts involved. Nevertheless, balancing differences and solving conflicts can offer remarkable opportunities for improvement."

Jan 1, 2016

By Rajesh K. Mishra

The person in charge of Environmental Affairs in a small business has many higher priority projects (such as making money to meet the employee? payroll etc.) than filling out and filing the regulatory forms. It is but. natural to think that these affairs can be managed? by playing ignorant until audited by the regulatory -state and federal agencies. Truth is to. the contrary; generally, it is too late by then. The fines and legal costs even for failing to file the regulatory forms could deliver a serious blow to the financial well-being of a small business. Forms and reports under SARA Title III are not hard to complete., but they are time consuming. In this paper we will discuss the information and data compilation procedures, simplification of some legal terminology into simple technical language, and tips that help in filling out the forms?. Some actual case 'histories of EPA fines will also be reviewed.

Jan 1, 1992

By J. F. Brune, A. Verma

"Face ignitions in underground coal mines are a major risk for underground mining operations, as they can lead to methane or coal dust explosions. The 2010 disaster at the Upper Big Branch Mine resulted in 29 fatalities due to a methane and coal dust explosion initiated from a face ignition. Much research has been conducted to mitigate face ignition hazards, from water sprays to installing passive and active explosion barriers. Despite the increased use of water sprays in U.S. coal mines, there have been more than 50 documented face ignitions in the U.S. underground coal mines since 2010, indicating that this hazard still prevails. This paper will examine the statistics of face ignitions and gas explosion in U.S. coal mines based on MSHA data. It will study factors contributing to these face ignitions and outline best practices for their prevention based on experience and practices worldwide. INTRODUCTION Methane and coal dust explosions are one of the major causes of coal mine disasters in the U.S. and around the world. Such disasters have resulted in the large number of fatalities and loss of mine infrastructure. The recent explosion at the Soma coal mine in Turkey has caused the death of 301 miners (Mining Turkey, 2014). As documented by U.S. Mine Safety and Health Administration (MSHA, 2015a), the U.S. coal mining industry has also experienced several catastrophic mine explosions with accidents at Upper Big Branch mine, Darby mine, Sago mine and Jim Walter Resources No. 5 mine in the last decade, causing the deaths of almost 60 miners. Every explosion requires a source of ignition, the right amount of fuel and oxygen. In underground coal mines, methane acts as a fuel while ventilation air acts as a source of oxygen. The source of ignition may vary from spontaneous combustion, electrical equipment and switchgear, mechanical heat sources, face ignitions due to friction rock-on-rock or from cutter bits and lightning strikes. Under the right conditions, energy of less than 0.3 mJ is sufficient to ignite methane-air mixtures (James, 2007) that can result in a catastrophic explosion. Much research has been done to mitigate the methane explosion hazard by proper dilution, continuous monitoring of methane and elimination of ignition sources. Historical studies indicate that face ignitions are the major cause of explosion in underground coal mining operations worldwide (Belle, Carey, and Robertson, 2012). Statistics shows that most mine disasters were started from a small face ignition, which turned into a major explosion fueled by additional methane and coal dust (Belle et al., 2012). To investigate face ignition hazards, researchers must study potential ignition sources as well as potential explosive atmospheres near mechanical coal cutting operations. Statistical analysis of U.S. coal mine face ignitions reported by the U.S. Mine Safety and Health Administration (MSHA, 2015b) shows that several factors are responsible for face ignitions."

Jan 1, 2016

By David M. Gullikson

As part of its program of petroleum production research the Federal Bureau of Mines has long been engaged in the study and development of systems of analysis of oilfield waters (8, 12, 20, 21, 22, 27, 30).21 However, many of the early chemical procedures developed by the Bureau and widely adopted by the petroleum industry are time consuming, and some are unreliable for determining certain constituents found in California oilfield waters. Because of the need for more rapid and more accurate methods having greater sensitivity with low concentrations of some constituents, a study has been made by the Bureau's Petroleum Research Laboratory at San Francisco, in developing new techniques and modifying previously published techniques for analyzing oilfield waters by flame spectrophotometric, potentiometric, and colorimetric methods. Test solutions were synthesized for testing the suitability and accuracy of the procedures, and the effect of interfering ions. These solutions contained known quantities of characteristic constituents of oilfield waters including sodium, magnesium, potassium, calcium, lithium, strontium, barium, sulfate, chloride, bromide, iodide, carbonate, bicarbonate and borates in a wide range of concentrations. The compositions of these synthetic brines are listed in table 22. Many California oilfield waters contain salts of petroleum-derived organic acids and several synthetic oilfield waters also were prepared to which large quantities of naphthenates or salts of petroleum acids were added.

Jan 1, 1961

By McHenry Mosier

This is the fourth progress report in the series on the use of detachable rock-drill bits in the metal mines of the United States. It contains comparative statistics and costs or drilling at eight mines not reviewed in previous reports, comparison of the use of detachable bits at small mines and large mines, a discussion on the life of drill rods, and general conclusions derived from an analysis of the rock-drilling practice at all the mines investigated on this survey. This paper completes the descriptions of operating practice in rock drilling at individual mines. Data on drilling practices at 28 mines are given in appendices I and II and drilling costs are shown in appendix III. Research in the fundamentals of rock drilling, including the use of detachable bits, has been undertaken by the Bureau of Mines in its testing adit at Mount Weather, Va. Reports on the progress off this investigation will be issued when results warrant their publication.

Jan 1, 1937

By Franklin H. Persse

The Bureau of Mines estimated reclamation costs for 13 surface coal mines in nine States west of the Missisisppi River. With the exception of the Pacific Coast coal province, at least one mine in each of the western coal provinces was studied. Cost estimates were, made using standard estimating procedures from data obtained from company records, interviews with industry personnel, and onsite observations. Estimated costs are presented in four categories which represent the four phases of mined-land reclamation: (1) Design, engineering, and overhead; (2) bond and permit fees; (3) backfilling and grading; and (4) revegetation. Estimated costs as of the first quarter of 1976 are expressed as averages and ranges in terms of per acre, per ton of coal produced, and per million Btu. Total reclamation costs ranged from $860 to $7,200 per acre, from 6 to 84 cents per ton, and from 4 to 35.3 mills per million Btu. A mine in the Northern Great Plains coal province (Region D) showed the highest per acre cost whereas mines in part of the western region of the Interior coal province (Region A) experienced the greatest per ton and per million Btu cost. The high cost of reclamation in the Western United States is reflected in the backfill in and grading category, particularly in the cost of topsoil removal and subsequent replacement as required by individual State reclamation regulations.

Jan 1, 1977

By P. Zhang

This paper gives a review of promising technologies for phosphate processing, and covers flotation, analysis and process control, as well as tailings treatment and utilization. Air bubbles of less than a µm in size, combined with relatively large bubbles, have been demonstrated, both in the lab and on a pilot scale, to improve flotation dramatically, by reducing reagent use while improving product grade. Innovative use of polymers has allowed rapid dewatering of fine tailings with a final product that does not segregate. The first online laser-induced breakdown spectroscopy (LIBS) analyzer was created, allowing rapid analysis of wet samples using the laser technology. Many large commercial projects are successfully pursuing the utilization of phosphogypsum.

Feb 1, 2012

By J. H. Rowland, A. C. Smith, K. A. Teacoach

Current regulations for fire suppression systems in underground coal mines to protect conveyor belt installations have been in place since the Coal Mine Health and Safety Act of 1969 was enacted. Over time, the coal conveyer equipment being used and ventilation conditions underground have changed significantly, particularly the width of the conveyor belts and the use of belt air at the face. The effect of these new conditions on the effectiveness of suppression systems during a fire is not known. The National Institute of Occupational Safety and Health (NIOSH) conducted a study to evaluate the effect of air velocity, water sprinkler activation temperature and a limited water application time on the effectiveness of water sprinkler fire suppression systems to extinguish large-scale conveyor belt fires. The fire tests were conducted using both new and used 1.8-m-wide, fire-resistant rubber belt that met the Mine Safety and Health Administration (MSHA) flame-resistant requirement specified in Title 30, Code of Federal Regulations, part 18, section 18.65 (also known as the 2G test). Tests were conducted using standard response sprinklers with activation temperatures of 68° C and 141° C at air velocities of 0.5 and 5.1 m/s. Two tests were conducted at both air velocities for each sprinkler activation temperature, one using a new belt and one with a used belt. The results showed that the suppression system was able to suppress the fires in ten minutes to the point that a miner could extinguish it with a fire hose. However, in several of the tests, the fire reestablished itself a few minutes after the sprinkler water supply was cut off and quickly grew out of control. This report discusses the large-scale experimental configuration, the installation specifications of the fire suppression system and the results and conclusions regarding the effect of air velocity, sprinkler activation temperature and limited water application on the suppression system performance.

Jan 1, 2010

By H. Hejny

Economy needs mineral raw materials in almost each sector of modern life. They can only be provided by mining activities. An increasing share of the total mining production will be by underground mining. The mineral deposits will be found at gradually greater depths, including all problems associated with them. It involves an increase in overburden pressure with subsequent rock stability problems and risks of structural collapse. There is a need for new and safe technologies for almost all parts of a modern mine. The mining industry faces a number of challenges which require technical solutions that encompass the entire network and include the economic, social and environmental issues. The industry needs a new image based on pioneering solutions and a modern structure that can exploit minerals at greater depths and promote both high productivity and safe working conditions. Funding has been secured from the European Commission for the I²Mine project. Work started in November, 2011. This initiative is designed to focus on the technological challenges that the mining industry is currently facing including the exploitation of ever deeper deposits and the aspiration for an invisible, safe, zero impact mine. The project comprises a consortium of 27 organisations from 10 European countries. I²Mine marks the start of a series of development activities aimed at realising the concept of an invisible, zero impact, deep mine. The extractive sector, still seen as being old fashioned and environmentally unfriendly, will show that mineral extraction and processing can be done in a highly innovative and sustainable manner with low impact underground and zero impact above ground. The concept of I²Mine is to develop innovative methods, technologies, machines and equipment necessary for the efficient exploitation of minerals and disposal of waste, all of which will be carried out underground. This will dramatically reduce the volume of surface transportation of both minerals and waste, minimising above ground installations and reducing the environmental impact. New eco-efficient technologies will be applied in order to make the entire mining process more efficient and environmentally sound. The concept is for an integrated mine, with the majority of the installations underground, and only the final product will be transported above ground to be shipped to the customer. Production waste will be treated and stored underground and gaseous emissions will be managed underground as far as practical. I²Mine will also focus on ideas and concepts that increase energy efficiency and decrease waste. The core of the project will be to develop breakthrough technologies for autonomous, highly selective, continuous mineral extraction processes and machinery based on new sensor technologies, face front separation as well as innovative concepts for mass flow management and transportation integrating state of the art technologies. The concept of an invisible, zero impact mine requires a refined process underground that selectively extracts the mineral thereby reducing waste. For this reason, improved extraction machines and near to face processing methods, including backfill procedures, need to be developed. These developments include rock mechanics and ground control solutions, incorporating health, safety and environmental issues.

Aug 1, 2013

By I. AITKENS

Tourmalines are among the most beautiful of all the semiprecious stones, and are unsurpassed even by corundum in variety of hue. The stones most suited to jewelry purposes are those comparatively free from iron. One reason for the fact that the tourmaline has advanced rapidly in public favor in this country is that it is found in California in great profusion and of extraordinary quality. The superb green and especially the pink crystals found at Pala and Mesa Grande in San Diego County, Calif., are deemed superior to tourmalines from all other localities.

Nov 1, 1931

By John R. Howell

"SUMMARYThe process of producing a new cast component requires significant design and development by both the design engineer and the foundry engineer. This effort strives to produce a high quality component at minimum cost. To assist in this development, an analysis system, consisting of several computer programs, has been developed to simulate the metal casting process. This system incorporates analytical geometric solid modeling, finite element analysis, results display, and an innovative technique to model the casting mold with surface boundary conditions.The simulation has produced excellent thermal results and work is in progress to develop techniques to enable use of this data in additional analyses to predict porosity and residual stress. Research is required to produce working parametric formulations of material properties. Software development is required to develop good fluid flow analyses for large. 3D models to simulate filling of and convection in molds.Integrating this system of programs is difficult due to proprietary database structures used by software developers. However, an acceptable means has been accomplished' to move data from one program to another. Further software development is required to facilitate this task. INTRODUCTIONThe process of producing a new cast component requires significant design and development by both the design and foundry engineer. This effort strives to produce a high quality, reliable component at minimum cost in a timely manner. The design engineer needs to know the physical and mechanical properites which can be expected in the actual part at critical areas. This will enable him to design a part with minimum material while fulfilling the performance required. The foundry engineer needs to produce a sound, quality casting with a minimal amount of material In risers, the feeding system and machining stock. This must be done with a minimum· investment in tooling and development time and maximum productivity of labor and capital employed. This task Is continually being made more difficult because of increased competition in the marketplace and the use of castings in more severe service. This has strongly influenced the need for high quality castings.The task of developing a new casting is difficult for both the design and foundry engineer. To assist in this development, Deere & Company has been engaged in the development of an analysis system to simulate material processes. A major portion of this program involves simulation of the metal casting process. This analysis system has evolved into a package of computer programs which simulates casting solidification and subsequent cooling through the finite element method"

Jan 1, 1986

By Alan Diaz Butron, Eng. Thierry Bernard

"In tunnel blasting the most challenging objective is definitively obtaining the maximum advanceassociated to a minimum overbreak. Achieving 100% of advance with no overbreak is the targetchallenge by Chavimochic Consortium. Chavimochic Special Project is an irrigation system that extends throughout much of the coast of the La Libertad Region, on the north coast of Peru. In 2012, it began management for construction of the third and last stage of CHAVIMOCHIC to irrigate lands of Chicama Valley, North of Trujillo. This project of 13 Km (8 mi) of various tunnels, it's a combination of technology and daily optimization by experienced people, which allow to accomplish the objective. Achieving this advance with no overbreak provide a huge saving on time. This paper describes the method, technology used, and the results obtained on more than 600 blasts done with conventional initiation system on the first 3 km (1.86 mi)."

Jan 1, 2017

By Clinton Birch

The multiple-criteria decision analysis is a technique that helps to find an optimal solution by evaluating conflicting criteria. In this study, an approach to perform multiple-criteria decision analysis for cut-off grade optimization, which considers the diverse stakeholder groups prevalent in the mining industry, is presented. The optimization model developed in this approach links the resource block model to the financial model, enabling the process to either maximize profit, net present value, revenue to the State, or extend the mine's life. To identify the optimal cut-off grade in each case, the Excel Solver function is utilized. Although it has limitations, the Solver function can still be modified to handle models with thousands of block values for determining input variables based on the target value. Following stakeholder engagement and dialogue, a single weighted average cut-off grade can then be determined. This approach is demonstrated for nine South African Witwatersrand gold mines.

Jun 25, 2023

By Andrea Zanon

Slitting processes have been used for many years to increase the productivity of smaller diameter deformed bars, without making major investments in the rolling mill. This technology is used mainly for the production of reinforcing bars (7-20 mm diameter), but successful applications exist also for round bar production. The multi-slitting process enables to produce up to 5 bars starting from one billet, thus increasing the productivity of the smaller products. Danieli Morgårdshammar, world leader in the supply of rolling mills for long products, has been a front-runner in slitting technology since its first applications and has recently developed, first in the world, the technology to produce 5X8mm rebar. This process has been recently applied in BRSM steel, a company based in Bangladesh which is a worldwide benchmark for slitting technology performances. This paper presents the necessary modifications which need to be considered when developing a 5-strand slitting project (and multi-strand slitting projects in general), as well as the results obtained at BSRM Steel when the process was implemented in 2016, the first rolling mill in the world rolling 5X8 mm slit rebars.

Oct 30, 2017

By N. Romani, R. Provost

"Commissioning of a circulating dry scrubber plant was recently completed at an existing facility, in order to treat the sulphur dioxide off-gas emitted from rotary kilns. Proper planning of the different commissioning stages and staffing an integrated team are the most important factors required for a successful plant start-up. A strong operational readiness plan must be in place as early as the start of construction in order to ensure a smooth transition from commissioning to operations. Plant performance can meet or exceed performance criteria within the required timeframe if the proper group dynamic and good communication is established between construction, commissioning and operations teams.INTRODUCTIONCommissioning of a circulating dry scrubber (CDS) plant was recently completed at an existing facility in Quebec, Canada. The CDS plant treats the sulphur dioxide off-gas emitted from rotary kilns in order to meet increasingly stringent environmental requirements. This installation enables the existing facility to reduce their sulphur emissions by over 90%.The CDS ProcessA general overview of the CDS process is presented in Figure 1 below. The combined, de-dusted off-gas from multiple kilns is sent to the CDS, which acts as an entrained fluid bed, where the gas is contacted with a water mist, re-circulated solids and hydrated lime. The SO2 from the gas stream and the available calcium hydroxide (Ca(OH)2) from the hydrated lime dissolve in the water and react to ultimately form calcium sulphites and gypsum. The solid residue (referred to as CDS residue), is the primary byproductof the process.Fresh hydrated lime and CDS residue is captured by the dust collection system and is re-circulated to the CDS via a fluidised transport system. Clean off-gas passes through the dust-collection system and is then sent to the atmosphere by a single exhaust fan.The CDS residue purged from the system is combined with the dust collected from the kiln offgas system and this mixture is wetted in the already exiting agglomeration system, to minimize dust generation during handling, and then sent to disposal."

Jan 1, 2016