Search Documents

By CHRISTOPHER D. HEBERT, SCOTT W. HOFFMAN

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. 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 individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2019

By R. Farrar

The survey work on protective canopy design was conducted in a 2-month period commencing November 15, 1973. The reported re¬sults under this contract are intended to provide guidance to coal mine operators in complying with federal regulations pertaining to incorporation of protective canopies on underground coal mine electric face equipment. All coal mine electric face equipment manufacturers and 11 coal mines were visited in the course of conducting this survey. Canopy designs currently being manufactured and those now being used underground were examined and discussed with manufacturers, mine operators, machine operators, and safety committeemen. The general objective was to find out what kind of canopies are now being made and used underground, what the operational problems are, and what can be done to secure improvements. Specifically, the survey scope was as follows: a. Survey all electric face equipment manufacturers. b. Survey 10 coal mines (seam height 60 inches and greater). c. Identify current production canopy configurations and minimum mine entry dimensions for each model and type of electric face equipment. d. Assess in-mine operation of canopies developed by manufacturers and/or coal companies. e. Specify optimal canopy configuration and minimum mine entry dimensions for each type and model of electric face equipment.

Jan 1, 1974

By Michelia Alba, Ronaldo S. Sampaio, Davi S. Braga, Mathieu Dubé

Climate change is pressuring industries and governments for decarbonization commitments, research, testing, and use of best practices to achieve the target of global warming below 1.5/2 °C. As it accounts for as much as 7% of all global CO2 emissions and 7% of energy consumption, the steel sector needs to address this issue with extended efforts. This paper provides information on the key potential of renewable biochar as an alternative fuel for pellet production. It also summarizes the successful application of biochar in a pioneering case study as the main fuel for a Grate-kiln pellet plant in Brazil, as well as the study of its use to replace coke and anthracite as an additive for iron ore pellets and other possible applications in the steel industry in COREM's precompetitive research & innovation program. The final discussion reveals the large quantity of biochar required by the Brazilian and Quebec scenarios for reducing CO2 emissions of iron ore pelletizing plants.

Jan 1, 2023

By W. A. Dunkley, W. W. Odell

About two-thirds of the manufactured gas supplied to the public by the gas plants in the Illinois district is cnrbureted water gas. The leading generator fuel is coke, ma.de in by-product c.oke ovens or in retorts, chiefly from eastern gas coals. During the fall and winter of 1917-18, when the demand for coke by war industries and the restrictions of the Fuel Administration in connection with the transportation of coke from eastern States made it almost impossible for many gas companies to obtain their coke requireml'nts, several water-gas plants had to use bituminous coal as generator fud. Many operating difficulties were encountered, some of which were solved more or less satisfactorily in different plants. A number of plants attacked the problem rather blindly because facilities for making tests were lacking and because technical men were too busy with labor and supply problems to study thoroughly the conditions involved or to ascertain what other plants had done with this fuel. It was therefore with the hope of assisting the gas industry during this critical period, and of promoting the use of Central District coals for gas making, that the Illinois Mining Investigations, a joint agency of the U. S. Bureau of Mines, the University of Illinois, and the Illinois Geological Survey Division undertook the, tests discussed in this paper. • This report was compiled under the auspices of a technical committee appointed by Gov. Frank 0. Lowden to promote the use of Central District coals in gas manufacture as a war measure. This committee included the following representatives of the various agencies concerned: U. S. Bureau of Mines, E. A. Holbrook and W. W. Odell; Illinois Gas Association, C. W. Bradley and R. B. Harper; University of Illinois, Dean C. R. Richards, Prof. S. W. Parr, and Prof. H. H. Stoek; State Geological Survey Division, F. W. De Wolf, G. H. Cady, a.nd W. A. Dunkley. F. W. De Wolf was chairxnan of the committee and E. A. Holbrook was secretary.

Jan 1, 1924

By P Bergin, J M. Galvin, J Harris, J Li, P Kirsch, M Shi, B Hebblewhite, B Whittaker, R Mitra, D Sprott

Controlling unwanted ground movement is critical in mining as well as many other highly hazardous environments, such as construction and tunnelling. Sharing knowledge about effective hazard management is paramount to improving health and safety and operational outcomes across industries, and some industry sectors have embraced this openness as part of the way that they do business. In 2010, the Australian Coal Association Research Program funded the RISKGATE project to build a body of knowledge for managing a broad range of hazards across mine sites, lease areas and mine infrastructure within a mine-life or product life cycle perspective (eg from exploration through to decommissioning, or design through to operation). The RISKGATE body of knowledge was assembled from Australian coal industry experts through a semi-structured bowtie analysis-based action research workshop cycle. By capturing operational knowledge from industry experts, RISKGATE serves to provide a cumulative corporate memory at a time of high personnel turnover in the coal industry.This paper presents an overview of RISKGATE topics within the geological and geotechnical domain (strata underground, ground control open cut, outburst, coal bumps and bursts, tailings dams and inrush) with a summary of individual topic structures, as well as showing the contrasts and inter-relationships between these ground management topics. The online user can access information about the causes, controls and consequences related to a priority unwanted event (ie the point at which control of energy is lost) and use this information as a prompt for the development of risk assessments, incident investigation, audits of practice/plans/procedures and for training and development.The paper concludes with a discussion of how RISKGATE can be adapted to other mining domains (eg coal outside of Australia, hard rock mining worldwide, construction, tunnelling) and the opportunity for application of this body of knowledge and the RISKGATE action research process for knowledge management in other highly hazardous environments.CITATION:Kirsch, P, Hebblewhite, B, Sprott, D, Harris, J, Li, J, Shi, M, Whittaker, B, Galvin, J M, Bergin, P, Mitra R and Williams, D, 2014. RISKGATE – shared coal mining knowledge for managing risks across ground management, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 247–254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By SME SME

NORTH AMERICAN TUNNELING 2024 PROCEEDINGS

Jun 23, 2024

By Samer Sadek, Brian Hagan

We are thrilled to welcome you to the 2025 Rapid Excavation and Tunneling Conference (RETC), which will be held in Dallas, TX. This year’s conference will showcase the continued trend of strong industry interest, as there will be a record setting 115 papers being presented over the course of three days. The set of papers compiled in this book captures the latest and greatest information on a broad array of topics within our fascinating tunneling industry. We hope that the compilation of selected papers in this book will provide a comprehensive recap of the conference while also providing a source of future reference for contractors, engineers, and anyone in general who is a student of our beloved and unique industry. Since its inception in 1972, RETC has been the preeminent tunneling forum to promote ideas, tell stories, share lessons learned, and promote new technologies. RETC prides itself on its focus towards highlighting real-world experiences and practical ideas, with the intent to help the entire industry learn from one another and grow. The need for us all to stay sharp and remain on the cutting edge of technology has never been stronger – the technology and ideas that have been applied in aerospace are now attempting to mix with tunneling, and the advancement of AI continues to permeate all industries. However, no amount of technology or AI can fully replace the human element, and in our tunneling industry, the human element is key and is what sets us apart. In tunneling, every project is different, because the ground is always different. We can only take what the ground will give us, and we must rely on our past experiences to get through present day challenges. Most importantly, we must rely on each other. This is the heart of what RETC is all about. For those of you attending this conference, we encourage you to attend as many sessions as possible and engage with your colleagues to discuss during the breaks in between sessions. This sharing of ideas is what keeps us connected and helps to expand our industry. Please also try to engage with the scholarship students and the newcomers who will be in attendance, as it is the new ideas and fresh energy from the next generation that will continue to make our industry thrive into the future. The program chairs thank and greatly appreciate the efforts made by our session chairs, co-chairs, authors, the members of the RETC Executive Committee, and most importantly the SME staff towards making this RETC possible.

Oct 1, 2025

By Bill Mariucci, Gary Almeraris

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. 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 individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2009

The value of domestic raw nonfuel mineral output in 1985 was estimated at $23.7 billion, 2% above the 1984 value of $23.1 billion. This crude mineral output was the basis for approximately $244 billion worth of processed materials of mineral origin. [ ] A U.S. company permanently closed its alumina plant in St. Croix, U.S. Virgin Islands, reducing domestic alumina capacity by 10%. Another U.S. company sold its 26% interest in an alumina plant in Jamaica to its two U.S. partners. On completion of the purchase agreement, the two remaining partners promptly closed the plant for an indefinite period, citing a world oversupply of alumina and unacceptably low prices.

Jan 1, 1986

By S. Mudau, P. Mohasoa, M. J. Cole

Derelict and ownerless (D&O) mines in South Africa have been an ongoing concern for over a decade. While some progress has been made to rehabilitate D&O asbestos sites, significant work remains, exacerbated by the growth in illegal mining. There are concerns regarding the accuracy and transparency of the D&O database, lack of oversight, and constrained funding, and the government is increasingly looking to the private sector to fund rehabilitation. Given these challenges, a new, sustainable approach to D&O sites in South Africa is needed to bring clarity and transparency to the process, recognise responsibilities and promote partnerships, and explore economic opportunities at D&O sites to reduce the financial liability and respond to the growing demand for critical minerals. This article has three components: i) reviews of international D&O good practices; ii) it analyses South Africa’s current approach and the D&O sites; and iii) proposes a D&O framework that addresses data, risk ratings, responsibilities and rehabilitation, economic opportunities, and stakeholder engagement. The study finds that the majority of the 6,100 so-called abandoned D&O mines are quarries and mine site features, 16% are operational, at least 11% have owners, and only 752 (12%) require rehabilitation. The framework aims to bring clarity and fairness to decision-making and to assign risk and responsibility for rehabilitation and seeks to incorporate economic opportunities to reduce the financial burden of rehabilitation, create jobs for local communities, and respond to the growing demand for critical minerals for the clean energy transition.

Apr 25, 2025

By H Kurth, L Balzan

On-belt analysers have been used since the early 1980s in the coal sector to measure ash content in real time for diverting material on conveyors to remove waste, bypass beneficiation and allow suitable material to proceed to the wash plant for processing. Since 2008, a GEOSCAN-M elemental analyser has been used on an overland conveyor in South Africa to divert direct-shipping quality iron ore to bypass a jig plant. This paper focusses on recent evaluation work to determine the suitability of an on-belt analyser to upgrade the processing plant feed in a copper-gold operation.Copper-gold ore samples from New Gold’s New Afton Mine near Kamloops, BC, Canada were tested to assess measurement accuracy over short time increments. A two-minute measurement increment has been used in the minerals sector as a compromise between good measurement accuracy and a useful tonnage (haul truck equivalent size or smaller). At New Afton, this increment represents approximately 35 t of material. Segregation decisions are currently made after visual and sometimes analytical determination, at increments of approximately 500 t to designate material as ore or waste at the drawbell in the cave.Results of test work including the composition range and expected accuracies by element are shown. The operation, which is not mine constrained, was evaluating the potential for ore upgrading through waste and low grade increment diversion to upgrade ore quality feeding the mill. Prompt-gamma neutron activation analysis (PGNAA) was considered as the company recognised that it would measure through the full conveyed cross section continuously and produce multi-elemental measurements unaffected by particle size, dust, moisture content, layering and segregation, mineralogy and belt speed.GEOSCAN analyses over various analysis periods will be collected to identify variability in the conveyed material quality and used to generate tonnage-grade curves so that an optimal diversion (bulk sorting) tonnage increment can be determined. Measurement increment time can be customised to suit site requirements. CITATION:Kurth, H and Balzan, L, 2017. Assessing bulk sorting suitability at the New Afton mine, in Proceedings MetPlant 2017, pp 315–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

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 Albert E. Long

THIS GLOSSARY is published lay the Bureau of Mines as a contribution too the mining literature to fill a long-felt need for a compilation of the terms used by the diamond-drilling industry. The first step toward preparation of the glossary was taken in October 1955 when the Diamond Core Drill Manufacturers Association (DCDMA) proposed that the Bureau of Mines undertake the cons compilation and publication of a glossary of the terms used by the diamond-drilling industry. The work was authorized in July 1956, and a preliminary draft of the glossary was completed in may 1958. Copies of the draft were submitted for review to members of the DCDMA and appropriate personnel of the Bureau of Mines. The final draft, incorporating the many helpful suggestions of the reviewers representing both the diamond-drilling industry and the Bureau of Mines, was completed in March 1959.

Jan 1, 1960

By C. L. Popp

The scope is to address issues confronted by parties in the mining industry such as: Mine planners, survey and engineering departments, field teams and subcontractors. Describing approaches and best practices for assembling a project team to identify and create modeling requirements and to implement beneficial results. 3D Machine Control and Guidance tools continue to reduce project risk and attract quality resources with skill sets new to the earthmoving industry. These tools increase production, reduce rework and help with government permitting.

May 1, 2013

By Robert G. Clarke

The production of natural abrasives varied in quantity and value compared with those of 1974. Output of tripoli-type materials and garnet both decreased in quantity and value. Special silica stone products decreased in quantity but in-creased in value. The production of emery increased 38% in quantity. The production of manufactured abrasive materials decreased for all types and the decreases were more in quantity than in value. [ ] FOREIGN TRADE Imports of abrasive materials were 15% less in value than in 1974, and exports plus reexports decreased in value 10%. Net exports, the excess of exports and reexports over imports, were $9.3 million, about four times that of 1974. The volume of all abrasive materials exported decreased and the value of nearly all decreased.

Jan 1, 1977

By J J. Robinson, B N. Noller, D M. Franks, G McIlveen, D R. Mulligan, A T. Soro

Fiji is a developing nation that relies on economic opportunities and recently experienced increased interest in mining and mineral exploration that could potentially benefit the country. In order to understand the lack of, or failure of, past rehabilitation activity, this study applied risk-based approaches to identify the significance of activities or actions applicable to rehabilitation of post-mined land in Fiji. This involved the use of qualitative, semi-quantitative and quantitative risk methodologies, which allow assessment and evaluation of mechanisms of mining administration and practices, as well as rehabilitation methods and approaches that have been applied successfully to post-mined land in other countries with similar environmental and climatic conditions and social and regulatory environments to Fiji. The semi-quantitative risk-based technique followed an earlier approach applied for mine closure by Laurence (2006) and provided a systematic way to assess and evaluate rehabilitation issues that were identified on-site by assessors, who were able to estimate through expert judgement the likelihood and consequences based on conditions, situations observed and circumstances on-site. It demonstrated that experienced professionals could reproducibly score likelihood and consequence of selected items relevant to mine site rehabilitation, despite the wide-ranging issues identified during post mined land rehabilitation. The quantitative risk-based approach was adopted as a method to determine environmental bonds for mining projects using the assessment of consequences and likelihood results from the semi-quantitative approach, then incorporating unit cost of materials or activities for local conditions required to fully rehabilitate each issue at net present value. Application to both an abandoned mine site and a newly opened mine site in Fiji showed that this approach could provide a risk-based estimate for rehabilitation cost and demonstrated potential applicable in the Fijian context.CITATION:Soro, A T, Mulligan, D R, McIlveen, G, Franks, D M, Robinson, J J and Noller, B N, ?2014. Risk-based Rehabilitation Strategies for Post-mined Land in Fiji, in Proceedings Life-of-Mine 2014 , pp 165–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By W. G. Pariseau

"The Crandall Canyon Mine (CCM) is located in the Wasatch coal field in central Utah. Extensive longwall mining at CCM preceded a decision to recover coal left in barrier pillars on each side of a set of main entries extending far into the mine. During mining in March 2007, a major bump occurred that led to cessation of mining in the barrier pillar on the north side of the mains and to the start of mining in the south barrier pillar. Subsequent loss of ground control in August 2007, through coal pillar bursts had tragic consequences with loss of six miners and shortly afterward three rescue team members. A U.S. Mine Safety and Health Administration (MSHA)report describes the events in detail (MSHA, 2008).An important lesson to be learned from CCM is the need to select a computer program suitable for pillar design. Computer programs are engineering tools and selecting the right tool for the job is essential. In this regard, minimum program requirements include capability for computing stress distribution within a pillar and adjacent roof and floor strata. The reason is simple: strength of rock is stress dependent; both vary from point to point in pillars and adjacent strata. Preferably, one should follow the evolution of stress as the mining plan is executed from start to finish to assure safety or to warn of a potentially hazardous situation developing as mining progresses.The approach to the problem posed by barrier pillar mining at CCM is conventional in the sense of applying well known finite element modeling techniques to analysis of a proposed mining plan. The engineering purpose is to evaluate the mining plan with respect to ground control questions including roof, floor and pillar safety. Results of previous two-dimensional finite element analysis indicated pillar safety was by no means assured (MSHA, 2008; Pariseau, 2008; Pariseau, 2011). Geometry of barrier pillar mining is limited in two dimensions for example, crosscuts are not seen in vertical cross sections. While three-dimensional analyses are preferred, even moderately sized regions often lead to very large problem sizes that exceed computer capabilities. However, a recent development in finite element modeling of tabular deposits allows for whole mine analysis in three dimensions. This technique involves a dual node - dual mesh concept. Both have been used separately in much earlier work, but are only now used in combination. It is possible to have an estimation of subsidence at a kilometer scale and details of stress, strain and displacement about barrier pillars, main entries and pillars, and so on at a meter scale (Pariseau, 2014). No compromise involving empirical formulas or similar guess work is required. Indeed, all calculations are based on first principles: physical laws, kinematics, and material laws. Effects of joints and in situ variability or uncertainty in strata properties, elastic moduli and strengths, may be included for greater realism. An important objective of the present study is to assess the role of three-dimensional pillar geometry in arriving at conclusions regarding barrier pillar mining versus two-dimensional results."

Jan 1, 2014

By Juan J. Monsalve, AMAN SONI, Nino Ripepi, Richard Bishop

The design and strength of pillars are important parameters when implementing the room-and-pillar mining method in a limestone mine. The process becomes complex with the presence of karst voids, which are frequent phenomena in carbonate rock formations. This research continues a previous study aimed at studying the effect of karst voids on the strength of a particular limestone pillar. Using calculated pillar strength and estimated redistributed stresses, it was assessed that the pillar can counter more stress than currently imparted on it. Numerical modeling studies combining in situ stress determination and excavation sequencing were used to estimate the existing stresses on the pillar. Different possibilities of modification to existing pillar design were simulated using distinct element method (DEM) modeling to determine a better design.

Jun 1, 2023

Real economic growth for the year will most likely exceed the Administration's estimate of 3.2%, up from 2.9% in 1986, unless consumers change their spending patterns more than expected as a result of the October stock market decline. The economy grew at a real annual rate of 3.7% in the first three quarters of the year, Analysts agree that the stock market decline will slow economic growth-- most have lowered their growth expectations for 1988 by about 1%; but few would argue that the economy will slow significantly in the fourth quarter of 1987. [ ] During this economic recovery, personal consumption expenditures provided the main impetus for growth and a deeping trade deficit, the main hindrance to growth. In 1987, however, personal consumption expenditures grew at a lower rate than the overall economy. Mush of the economic growth resulted from a reduced trade deficit and growing investment by business in equipment to improve productivity and to meet the domestic and foreign demand for products. The declining value of the dollar resulted in a better competitive position for U.S. goods but also contributed to a rising rate of inflation as imports rose in price. Inflation, as measured by the fixed-weighted index for gross national product, was still far below the rates in the early 1980k, however. More than 2 million jobs were created during the year, predominantly in the service sectors of the economy, and the monthly unemployment rate in September fell to the lowest level in a decade. Then, after 13 months of decline, the unemployment rate edged up 0.1 percentage point to 5.9% in October.

Jan 1, 1987

By N. Duda, W. Koperska, S. Anufriiev, P. Stefaniak

In mineral processing plants ore extracted from mines is processed to obtain a concentrate with the highest possible concentration of this valuable product. It is a complicated multi-stage process. Usually, the first step is sieving the ore, which is typically done using vibrating mining screens. There is often only a limited number of these machines in the technological chain, which is why their continuous operation, and proper maintenance is crucial for the whole process. Predictive maintenance is the best strategy in this case because it allows for minimising the number and duration of unexpected stoppages. It consists of the prediction of future failures based on available real-time data, and predictive models built upon this data using, for example, machine learning techniques. In this paper we concentrate on feature generation for future predictive maintenance model development for a vibrating screen, based on an example of a KGHM ore processing facility in Polkowice-Sieroszowice. We focus on two types of measurements: bearings temperature and vibrational data. Based on the raw data, the process of more advanced feature engineering is described. By transforming the temperature data we calculate characteristics of bearing cooling and heating dynamics, while based on vibrational data, the aggregated characteristics of the vibrations are derived. Such features are calculated on a long-term basis, and then they are compared to the data related to vibrating screen maintenance to estimate their significance for the prediction of particular failures of the machine.

Sep 1, 2021