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By David C. Grant

In situ uranium mining offers the advantages of minimal environmental disturbance, low capital and operating costs, and reduced mining development time. It is becoming an increasingly attractive mining method for the recovery of uranium from secondary ore deposits. In order to better understand the process, a laboratory technique was developed and used to study and simulate both the chemical and physical phenomena occurring in ore bodies during in situ leaching. The laboratory simulation technique has been used to determine effects of leaching variables on permeability uranium recovery, and post-leach aquifer restoration. This report describes the simulation system and testing procedure in sufficient detail to allow the construction of the system, and to perform the desired leaching tests. With construction of such a system, in situ leaching of a given ore using various leach conditions can be evaluated relatively rapidly in the laboratory. Not only could optimum leach conditions be selected for existing ore bodies, but also exploitation of new ore bodies could be accelerated.

Jan 1, 1985

By Herbert R. Babitzke

The Minerals Availability System (MAS) was formally established by the Bureau of Mines in May 1975 to provide current appraisals of the engineering and economic availability of nonfuel minerals for consideration in the formulation of both domestic and foreign minerals policy, Domes- tic mineral property reports are developed by the Bureau's four Field Operations Centers, and foreign data are obtained under contract. This site-specific information is subsequently subjected to engineering verification and economic evaluation, and the results are analyzed and published as Minerals Availability System Appraisals. The deposit-specific data are also entered into the computerized MAS data base, where a subset of this information, the Mineral Industry Location System (MILS), is available to the public in the form of computer graphics and listings. Other MAS products are also described. The Bureau's MAS personnel are frequently involved in special engineering and mineral economic projects for other Federal and State agencies. MAS personnel also work closely with the private sector, both in the area of mining and processing cost estimation, and as a source of nonproprietary mineral deposit information.

Jan 1, 1982

This report, the fourth in an annual series, outlines recent trends and developments in the minerals industry. Discussed are new methods, equipment, techniques, and systems used to more effectively extract and process mineral products. Environmental considerations, health and safety standards, price controls, inflation, material shortages, and more dependence on foreign imports were problems faced by the minerals industry. Although productivity increased for most mineral commodities, the annual rate of increase has slowed in recent years, indicating a maturing technological situation. Growing concern for energy resulted in increased interest and research in alternative fuel sources. The primary concerns of metallurgists were pollution control and improved efficiency and performance of metallurgical processes, especially for reduction of energy consumption.

Jan 1, 1974

By W. H. Ryback

When a fire or explosion occurs in an underground coal mine, the atmosphere guickly becomes irrespirable. Highly irritant smoke and toxic levels of carbon monoxide and dioxide are produced, and consumption of oxygen by the fire or blast can reduce its concentration below that needed to support life. Work parties entering such a hazardous atmosphere for rescue or recovery operations are required to use, as their primary respiratory protection, a fully self-contained breathing apparatus of at least two hours duration. Apparatus used in this role has primarily been of the closed circuit rebreather type, using pressurized oxygen storage and chemical removal of expired carbon dioxide. Typically, commercial self-contained breathing devices for mine rescue have been heavy, bulky, and uncomfortable to use. The McCaa apparatus, long the industry standard, represented the best art available when it was First designed in 1926. It weighs 41 Ibs., protrudes about six inches above shoulder height, and provides breathing gas at temperatures up to 120° F. More recent designs, such as the Drager BG174A and Scott Rescue-Pak, using modern light weight materials and fabrication techniques have improved on all parameters of the McCaa to some extent. It was the intent of the Bureau of Mines, acting under the authority of the Coal Mine Health and Safety Act of 1969, to fund the development of a new self-contained breathing apparatus which would incorporate the best available technology and serve as a benchmark for future commercial designs, as the Bureau-sponsored McCaa had 45 years previously.

Jan 1, 1974

By Manuel Gomez

Coking time was investigated as a function of coal properties, carbonization parameters, and the interactions between these variables. The results indicate that coal properties and carbonization conditions interact to influence the coking time, and these interactions may be determined quantitatively. Prediction equations were developed and used to simulate the effects of bulk density, flue temperature, and oven width on coking times for coals having a wide range of properties. The data presented provide additional information on the carbonization process to permit the coke oven operator to maintain closer control of coke production and coke uniformity.

Jan 1, 1968

By Paul Sterling

1. INTRODUCTION. THE general impression regarding the preparation of merchantable anthracite is that it is confined to a colossal, grimy structure, called a "coal-breaker." This name is misnomer; for the desired result is not to break the coal, but to prevent its being broken. Preparation may be said to begin at the face of the chamber, with the mining and loading of the coal. Local conditions vary, not only in the same field or basin, but also in the same mine, so that there is no fixed empirical rule governing the method of blasting or cutting coal. Tests should be made, when possible, to determine the explosive, or the mechanical coal-cutter, which will produce the largest percentage of what are locally known as " lump " and " prepared sizes " of anthracite. The prepared sizes are those mostly consumed for domestic purposes. All other sizes might be called by-products of the anthracite industry; for they are not especially desirable, being the degradation resulting from the mining and handling of a brittle or laminated material. Being low in volatile combustible matter, anthracite burns most successfully when nearly of a uniform size, permitting the easy passage of air through the voids. This accounts for the large number of sizes into which the coal is separated. Table I. gives the various sizes, the diameter of ring over and through which each size is made, and the usual purpose for which it is employed.

Oct 1, 1911

By Tim O’Neil

Nearly 4,800 mining professionals and exhibitors occupying 580 booths attended the 2000 SME Annual Meeting and Exhibit, Feb. 28-March 1, in Salt Lake City, UT. The technical program included80 sessions and four specialty symposia: bulk material handling, control 2000, minor elements 2000 and plant operaters. Meeting highlights included the keynote session. Executive shared their perspectives on pivotal issues and approaches to address the challenges of the new millennium. SME has begun planning for its 2001 Annual Meeting, Feb. 26-28, in Denver, CO. The meeting carries the theme “2001 — A Mining Odyssey.” A call for papers has been issued and exhibit space is 80% reserved. For information, visit SME’s website, www.sme-net.org. Or write Box 625002, Littleton, CO 80162-5002,ph 800 763 3132 or 303 973 9550, fax 303 979 3461, or email meetings@smenet.org.

Jan 1, 2000

"Chairman: Professor E. P. PFLEIDER Rapporteur: Mr P. R. JANISCHPapers:Optimum design of an open pit by D. A. PhillipsAn open pit design system for stratiform ore bodies by L. A. J. Pronk van Hoogeveen, J. R. Cutland and M. WeirAn open pit design model by R. H. Robinson and N. B. PrennThe Chairman in opening the session highlighted the current situation in the United States of America where some 85 to 90 per cent of all mining (except for coal) is done by open pit methods, and where some 40 per cent of the coal is mined by open pit. The South African industry is, of course, dominated by the deeper level underground gold mines; however, with the aid of an extensive open-pit technology developed in other countries, South African companies arc continuing to explore possibilities of open-pit exploitation of base mineral, coal and diamond deposits. Several successful ventures are already in operation at Phalabora, Optimum Colliery, Kimberley and elsewhere, and South Africa is undoubtedly benefitting in this regard by drawing on the experience of others.The papers of this session were therefore particularly pertinent, particularly when viewed in conjunction with those presented at an earlier South African conference devoted specifically to open pit mining.Two themes dominated the discussion which followed presentation of the three papers at this session. The first related to the practicability of using the reported techniques as a tool for management, and their acceptability as such to mine management. This was, of course, not peculiar to this particular session, but rather the major point of debate over the entire conference.The second theme concerned the reliability of the initial drill hole data on which any open-pit design must necessarily be based. This gave added emphasis to the problem of practicability, for no management is likely to accept an elaborate pit design unless confidence can be placed in the ore reserve assessment.In noting these two features of the discussion, it should be remembered that all the three papers dealt largely with design and pre-planning; there was an unfortunate lack of papers or discussion on the subject of controlling the day-to-day mining of open pits, and this is an area where the potential impact which can be made by the computer is even greater.In introducing his paper, Mr D. A. Phillips pointed out that it was concerned only with optimization, and that it therefore assumed, firstly, an adequate subdivision of the orebody into ore blocks characterized by grade, rock type, structure, etc., and, secondly, an acceptable forecast of costs and mineral prices in order to generate a suitable profit matrix. However, programs dealing with these problems for both massive, disseminated and stratiform ore bodies are available to Roan Consolidated Mines. The method of optimization which he had described had been used on a region split into 28 000 blocks, for which the program used three hours of C.P.U. time on an IBM 360/40 computer. The computer design had provided a three per cent improve¬ment on a normal design of the same area."

Jan 1, 2014

By Michael J. Brnich

During the past 15 years the number of reportable mine fires has declined. A decline in the number of reportable fires is a gross indicator that allows experts to say something about the underground coal industry generally: There has been some improvement in overall mine fire preparedness. However, such an indicator is less reliable as a predictor of readiness at any particular operation. An indication of fire fighting preparedness would have to be assessed from evidence gathered at the mine site. In other words, there are two levels from which to view the problem. On a general level, there has been significant improvement in the industry's fire response capabilities over the past two decades. Specifically, however, little data has been gathered on a site-by-site basis to determine what improvements might be made on a local level. These improvements would move beyond regulatory compliance. It is expected that this manuscript, based on work conducted at an underground coal mine in the western United States, will help to focus attention on some central concerns involving this critical issue.

Jan 1, 2006

By I. M. S. Moraes

Caraiba Metais has a plant for the purification and the cristallization of the crude nickel sulfate removed from its copper electrolyte purification system. In November 1994, an interdepartmental group was formed to study the Q.F.D. method, through its application on the improvement of the quality of the nickel sulphate hexahydrate. The team, formed with representatives of the following areas : production, technology, marketing, sales, maintenance, laboratory and TQC office, had also the task of checking the applicability of the method to other products of the comp any. This paper describes the main steps such as the survey of customer's demands, the preparation o1 the quality matrix, stablishing the planned quality matrix, the planned and the designed quality, and the consequent identification of the engineering bottlenecks. It is also shown how these bottllenecks were studied and solved. The application of the method allowed the team to identify means of increasing the production capacity by 40%, to improve the intrinsic quality of the product (including packaging), and to increase the reliability of the process.

Jan 1, 1997

By F. Chiesa

Experimental results on thin and thick castings poured in aluminum A356 and magnesium AZ91E by the low pressure permanent mold process have been compared to the result of filling simulations for thin and thick castings. If the results of modeling is reliable when the liquid remains above the liquidus temperature, this is no longer the case when partial solidification occurs. The visco-elastic behavior of a partially solidified liquid is difficult to put into equation as it depends on the amount of shear it has been been subjected to. Attempts to predict misruns with a commercial software has been proven to be very difficult if not impossible; divergence of the numerical solution has been observed unless prohibitively long computing times are used. In order to overcome these difficulties from a practical standpoint, a simple method is proposed which consists in tracking the temperature of the advancing liquid metal front so as to make sure it will always be above so-called `Misrun Critical Temperature' (MCT) determined experimentally for thin and thick aluminum A356 and magnesium AZ91E castings. If the liquid metal front falls below this temperature, a cold-shut or misrun is likely to happen at this location. The values of MCT for thin and thick in aluminum A356 and magnesium AZ91E were determined experimentally on misrun castings of extreme geometries (a thin 2.5 mm wall cover and a 6mm to 25 mm thick bell housing). MCT was found to be lower for magnesium AZ91E and for the thicker castings.

Jan 1, 2011

By Gordon MacVean

The object of this paper is to present for your consideration some of the present-day trends of safety practice in the coal mines in the United States and Canada. Coal mining at its best is a hazardous occupation. Men must be experienced miners in order to appreciate the existing hazards and must remain ever conscious of them if they are to work safely. The question is often asked whether our efforts for increased safety are showing results. So often it appears that strides are made for a period of a few years in the reduction of fatalities and lost-time accidents only to have all ground lost by an unfortunate year, after which progress is commenced again only to have a repetition of the same thing. Table No. 1 is an answer to this question. It shows the fatality rates over the last two decades in the coal mines of the United States and Canada. These are given in divisions of five years. The general trend is noticeably downward, exceptions being due to explosions or disasters which claimed an unusually heavy toll of life. These last are certainly not as common today as they have been in the past. It is only reasonable to suppose that this trend towards a lower fatality rate is the result of well directed safety effort. Reliable statistical organizations have offered figures to the effect that only 15 per cent of all accidents can be eliminated by the use of mechanical safeguards. The state of mind of the man involved, or his attitude towards safety, commonly called 'safety-consciousness,' is the controlling factor in the prevention of 85 per cent of our accidents.

Jan 1, 1931

By Evan Dressel, Mark S. Diederichs, Kathy Kalenchuk

As hard rock mining develops deeper over time, there is an increasing need to predict the spatial and temporal distribution of adverse seismogenic rockmass reaction to mining. Real-time monitoring and feedback of mine data are used to tactically manage risk associated with induced-seismicity; however, strategic risk management requires reliable tools for forward predictions of seismic hazard. The forward prediction of seismic hazard is strengthened by understanding of potential seismic intensity, which often relies on well calibrated mine-wide numerical models. This paper uses a case study to explore how future seismogenic potential and the nature of future seismicity can be domained according to numerically predicted stress-strain paths at past seismic event locations. Delineation of high confinement seismogenic volumes vs. lower-confinement, high-strain seismogenic volumes at the mine-scale can be achieved, based on a loading and unloading stress path analogue, to refine understanding of seismic intensity. Practical qualitative and quantitative methods to achieve this delineation will be demonstrated. Once seismogenic mode (high-stress vs. high-strain) is identified, detailed analyses of seismic source parameters demonstrates change in seismic hazard between the domained volumes.

Apr 26, 2022

By K. H. March

In the present very highly competitive condition of the bituminous coal business, it is becoming increasingly apparent that coal mines which do not lend themselves to efficient mechanization cannot long survive. It would seem that those mining operations best fitted to survive the struggle for existence are burdened with the considerable capital and maintenance cast of carefully selected mechanical and electrical mining equipment. The ever changing conditions of coal mine operations require equipment which is adaptable to a variety of uses; and investigation of the mechanical and electrical equipment in most mines will show that the operating duty of much of this equipment is considerably different from that duty for which it was originally selected. And it would appear that one of the essential qualifications for a successful mine management is a marked ability to get satisfactory operating results from equipment which has been transferred from some other operation, rebuilt, rearranged, or in some way adapted to the job at hand. As a striking example of such mechanical ingenuity, many of us recall that the first longwall jigging conveyor used in Nova Scotia was built in Sydney Mines from odds and ends in the scrap pile at a total cost of less than $50.

Jan 1, 1930

By A. Johnson

When are SMART transmitters the smartest choice? To answer this question requires a closer look at SMART transmitter technology. It is necessary to understand this technology in order to recognize how it can best be utilized to give the greatest value for the application. And, once the decision to buy transmitters has been made, it becomes a question of whose SMART transmitter to buy. For, although the under-lying technology is similar, the differences that exist in how the technology has been implemented can make a dramatic difference in the end result. What prudent users of SMART technology do is to analyze their needs by application before making their buying decision.

Jan 1, 1988

Innovation ? In economics a change must increase overall value, customer value, or producer value. ? Innovations are intended to make someone better off, and the succession of many innovations adds growth to the whole economy. ? Innovation may refer to both radical and incremental changes to either products, processes or services.

Feb 1, 2008

By M. Soltanieh

The liquidus surface? and tie-lines in the nickel-cobalt-sulphur ternary system have been determined between 1<273-1573 K. The experiments were conducted by equlibrating the liquid sulphide with the metallic alloy phase. The liquid sulphide phase was sampled and chemically analyzed. The alloy was analyzed by electrol} microprobe. Combining the present results with the.avai1abl~ literature data, the thermodynamic properties of this system were calculated.

Jan 1, 1998

By H Ş. Duzgun

It is expected that the future of mines will heavily adopt autonomy. However, problems with leveraging workforce transition, meeting Sustainable Development Goals, SDG’s (poverty, reduced inequalities), managing uncertainties (geologic, operational, economic), cybersecurity (connectivity, cyber-physical infrastructure) and innovation (transformative processes, real-time decision-making etc) are required to be solved for the intended autonomy. These problems also impact the safety of the future mine environment. The AI technologies provide a broad range of opportunities for enhancing mine safety. However, development of an accurate AI model for mine safety requires a large number of data, which may not be readily available to overcome the associated uncertainties in the mine environment.

May 5, 2022

By MYRIAM FRANCOEUR, JOHN R.R. BOWLING, ADAM MCFADDEN

As duct-fan systems push the envelope of power, length and cost, their design calls for a more comprehensive technoeconomic analysis to ensure they deliver the expected results without failure and cost overrun. This work explores the numerous factors to include in the design of an extensive (semi-)rigid duct-fan system. Besides delivering a given airflow, the system must satisfy component limitations and power constraints during its lifetime. We evaluate the assumptions underlying the positioning of in-line booster fans in a long gapless duct-fan system and propose a strategy for specifying the location and blade pitch of successive booster fans to prevent system failure due to a partial vacuum.

Oct 1, 2022

By Mario Gerards, Sergej Podkow, Marco Steinberg

"The JONES® WHIMS technology is based on the magnetic separation process and is widely used for the recovery of magnetically susceptible iron ore particles. The conventional machine design is well-known within the iron ore beneficiation industry for more than 50 years and recognized to be highly reliable, robust and extremely compact with the advantages of high capacity and selectivity. In 1981 Rana Gruber AS, Norway bought 14 JONES® WHIMS DP 317 separators when the magnetic separation plant was built and erected. Today, 11 of these old machines are still operating profitably and efficiently. The former supplier was the coal and minerals division of Klöckner-Humboldt-Deutz (KHD) which is today MBE Coal & Minerals Technology GmbH (MBE). This paper outlines a detailed description of the project of revamping the above mentioned old machines and describes the challenge of incorporating enhanced and newly developed technology into an existing processing plant. Further it gives an overview of the recent developments on the design of the JONES® WHIMS. In order to meet modern product requirements and to increase and secure plant productivity, in 2012 Rana Gruber AS settled a contract covering two new designed JONES® WHIMS DP 317 HFR separators to be implemented into the existing building and the upgrading of all 11 older JONES® WHIMS under the use of as many refurbished items as possible. The two new machines were fully developed by the product specialists of the supplier in cooperation with the operator Rana Gruber AS, thereby taking advantage of their great experience. The design of the new machine is based on the conventional design, i.e. the general operating mode as well as the overall dimensions are identical. Finally this paper gives an overview about the erection and commission phase of the two new machines and gives a detailed comparison between conventional and enhanced WHIMS technology."

Jan 1, 2014