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[ ] ALVA L. SMITH RMCMI PRESIDENT 1989-1990 on behalf of the RMCMI Board of Directors and Officers of The Rocky Mountain Coal Mining Institute cordially invites you and your family to attend the 86th Regular Meeting and Convention to be held June 24, 25 and 26, 1990 at Sheraton Steamboat Steamboat Springs, Colorado

Jan 1, 1989

By Esher Hsu

In Taiwan, around 8,000 tons of batteries are consumed per year but only 17% of which were collected and transported to oversea for recovery. The dumping used batteries have become a potential environment problem. How to increase the collection efficiency of used batteries is an important issue for EPA in Taiwan. Besides, some treatment plants are on process to get permission for recovering used batteries. The objective of this study is to estimate the recycling cost of spent consumer battery and explore the feasibility of recovering used consumer batteries in Taiwan based upon the principle of cost-efficiency. The recycling cost including collection cost and recovery is estimated based on a survey. Results would provide some suggestions to Taiwan EPA regarding feasibility of recovering used batteries in Taiwan.

Jan 1, 2006

By X. B. Zhao, J. G. Cai

The purpose of this paper is to incorporate the dynamic BB model of rock fracture normal behaviour into Universal Distinct Element Code (UDEC), and to conduct UDEC modelling to predict stress wave propagation across rock fractures. With the incorporation of new dynamic model of fractures, the UDEC is improved in the capability of modelling wave propagation across fractures. In this study, the case of normally incident P-wave transmission across a fracture is modelled, and the effect of dynamic normal behaviour of fracture is concentrated on. Wave transmission coefficient for wave transmission across the fracture with the dynamic BB model is obtained for various combinations of fracture dynamic parameters, as well as different wave amplitudes and frequencies.

Jan 1, 2003

By William L. Crentz

Early in the nineteenth century, coal from Clearfield County entered the eastern commercial market. Ashley reports that coal was moved down the Susquehanna River by ark from Clearfield to Columbia, a distance of 260 miles, as early as 18o4. Around 1850, the famous Moshannon or Lower Freeport bed was discovered. Several years later the Moshannon Basin was developed extensively, and the coal from this area soon acquired an enviable reputation as a high-quality industrial fuel. Today much of the original Moshannon Basin coal is worked out, and the Lower Kittanning bed has replaced the Lower Freeport bed as the principal source of production in southeast Clearfield County. With depletion of the thick underground deposits, the importance 'of Clearfield County as a coal Producer would have diminished rapidly, if it had not been for strip mining the thinner beds. About 60 percent of the coal produced in the county is strip-mined, and the trend toward this mining method is expected to continue as the older underground operations are exhausted. Many strip mines are working in beds that are too thin to be recovered economically by any other method.

Jan 1, 1952

By Swades Kumar Chaulya, Vikash Kumar, Sushma Kumari, Naresh Kumar, Girendra Mohan Prasad, Monika Choudhary

During harsh weather conditions, the presence of fog, dust in the environment degrades the image’s quality, which affects the visibility of drivers of heavy earth-moving machinery in opencast mines. Due to low visibility, mining operations cannot be carried out as drivers are easily prone to accidents. This paper proposes a technique that includes developing a vision enhancement system called perceptive driving assistant system for increasing visibility of real-time video of the road in front of the vehicle for operators of heavy earth-moving machinery at opencast mines during harsh weather conditions to overcome the problem. The system consists of high-quality Internet Protocol cameras and thermal cameras for real-time image processing and other well-defined devices, which is quite capable of enhancing the visibility of the image, outlining edges of the road, and detecting obstacles present on the path of operators for smooth driving and reducing threat of accidents. A high-speed graphical processing unit has been used for quality-performance parallel computing, which is well suited for real-time operations to empower fast real-time operations. The calculated frame per second (fps) of image enhancement, object detection, and edge detection is 17.91, 15.91, and 25.09 fps, respectively. The actual frame rate is 26.07 fps, and after applying the algorithm, the final frame rate is 19.65 fps. The calculated accuracy of the object detection model is 81.23%. Field trials indicate that the developed system has performed adequately during foggy weather.

Sep 21, 2022

By E. C. Harder

BAUXITE is known mainly as the ore from which aluminum is smelted but it has large use also in the manufacture of artificial abrasives and as a basis for certain chemical industries. A small amount is used for refractories and for other purposes. COMPOSITION Dana and others give the mineral formula of bauxite as A1203.2H20 and the composition as A12037 73.9 pct; H2O, 26.1 pct. It has been definitely shown, however, that bauxite does not exist as a specific mineral but rather as a rock. The term is now used synonymously with aluminum ore and it embraces gibbsite (hydrargillite or alpha trihydrate), A1203.3H20 (A12037 65.4 pct; H2O, 34.6 pct); boehmite (alpha mono¬hydrate), A1203.H20(Al203) 85 pct; H2O, 15 pct); diaspore (beta monohydrate), A1203.H2O(A12037 85 pct; H2O, 15 pct), and mixtures in various proportions of any two of them. Bauxite of the Mesozoic and Cenozoic in Europe is predominantly a mixture of gibbsite and boehmite, subordinately a mixture of boehmite and diaspore, or gibbsite and diaspore. The bauxite of North and South America, tropical Africa, Asia, and Australasia consists largely of gibbsite. Corundum (A1203) is not included under bauxite, although gradations from bauxite to emery or corundum exist. All bauxite, irrespective of the aluminum minerals composing it, contains certain impurities, including silica, in the form of clay minerals (kaolinite, halloysite, and others) or quartz, iron oxide (as hematite or goethite), titania (as leucoxene or rutile), iron sulphide (as pyrite or marcasite), iron carbonate (siderite), and calcium carbonate (as calcite); the last three mentioned in minor amount and of local occurrence only. Bauxite belongs to a group of partly consolidated materials called laterites, formed by surface weathering. This group includes also impure siliceous and ferruginous bauxite and siliceous and

Jan 1, 1949

By J. R. Thoenen

During the past 6 years the Mining Division of the U.S. Bureau of Mines has prepared many information circulars containing valuable technical data covering the operating details of mining and ore-dressing plants throughout the United States, Canada, Mexico, and other countries. These papers, written for the most part by operating officials in the field, have been designed to comprise a reference library for the operating engineer. In order to make the information contained in these publications more readily available to the busy engineer the enclosed series of reference tables has been compiled. The tabular arrangement is by subject rather than alphabetical order, thus avoiding the bulk of an alphabetical index.

Jan 1, 1935

By William R. Yernberg

The combined 79th Annual Minnesota Section of SME Meeting and 67th Annual University of Minnesota Mining Symposium was held April 11 and 12, 2006, in Duluth, MN. About 300 mining professionals attended, including engineers, executives, mining managers and suppliers, from throughout the United States and Canada. This year’s theme was “Success in the New World of Mining.” The SME Minnesota Section meeting included a keynote session, a special projects update, a general managers update and technical paper presentations. The University of Minnesota Mining Symposium program featured a panel discussion on Minnesota’s relationship with China. The combined meeting included a trade-show consisting of 64 booth spaces. Tradeshow demand exceeded expectations, and an additional 10 booth spaces were added in the registration lobby. Also included were an SME short course on pump basics and social events.

Jan 1, 2006

By Larry G. Stolarczyk

An underground medium frequency radio communications system has been developed and demonstrated in both coal and metal/non metal mines. The principal advantage of the system are its low cost, ease of installation and the ability to provide radio communications to any vehicle or roving miner in the underground mine. The system provides high quality radio coverage in work areas and along manways with existing "wireplant" conductors. The conductors include AC power cable, telephone cable, metal water and high pressure air pipes, etc. The measured communications range from the base station to mobile transceiver exceeded 12,500 ft without the use of repeaters. A cost/benefit analysis shows that the initial cost of the equipment can be returned 2-6 times in the first year. The mine productivity increases by approx. 13 percent.

By Tom Martin

Mega projects present unique challenges with regard to estimating costs. With such projects, which may span decades, these challenges often begin as soon as a project is conceived. The importance of having a sound, resource based estimate avail-able early in the process cannot be overstated because it provides the basis for ongoing project decisions. For the final phase of providing an updated cost estimate, often while bidding by contractors is underway, the Engineer?s Estimate (EE) must incorporate present market conditions; account for possible volatile material price swings; be based on actual labor and fringe costs; rely on meaningful productivity rates; and accommodate any recent technology advances while identifying and allowing for risk factors. This paper explains the benefits associated with consultants adopting a contractor?s estimating approach when preparing the Engineer?s Estimate on mega projects like the various tunneling projects in New York City.

By James F. Kvitkovich, George V. Weisdack

Longwall mining techniques were introduced into U.S. bituminous coal mining operations in the early 1960s. These techniques were gradually adopted by many mines during the 1970s. By 1983, considered to be the peak of the longwall mine census, there were 118 active longwall faces in 79 coal mines throughout the United States. Beginning in 1984, longwall faces began a decline in numbers that has continued to the present day (Fig. 1). The geographic distribution of longwall faces today is shown in Fig.2 according to region. A breakdown of recent longwall mine production by region is shown in Table 1. An approximate breakdown of present longwall face installations by product (metallurgical and steam) is shown in Table 2.

Jan 1, 2005

When it comes to processing industries, speed matters. More precisely, the faster/greater the throughput of finished product out the door, the more quickly money can flow back into the corporate coffers. In this quest for greater output, no processor can afford any weak links in the chain. Especially in the case of bulk solids operations, any one piece of equipment that slows the process down jeopardizes the profitability of the entire plant. However, one clay processor uncorked a pre-existing bottleneck by replacing its outdated separating equipment with a new design that immediately improved output.

Jan 1, 2007

By B. D. Lichter

In a previous paper, Oelsen, Schuermann, and Hey-nertl pointed out the possibility of obtaining complete thermodynamic functions for alloy systems from calorimetric measurements alone. Specifically, if the heat content of a heterogeneous, multicomponent system is known as a function of temperature and composition, then it is possible to derive the heats, entropies, and free energies of formation of liquid phases and of solid intermediate phases of fixed composition. The authors present equations and graphical techniques applicable to eutectic systems and systems with intermediate phases without solid solubility at lower temperatures. eijering has considered possible extension of the treatment to systems with complete solid-state miscibility at lower temperatures; however, experimental difficulties practically restrict the method to systems with very limited miscibility in the solid state. The purpose of this note is to present an alternative derivation of the heats and entropies of formation of liquid phases and of solid intermediate phases from heat-content measurements alone. Fig. 1 shows three types of phase diagram to which the analysis may be applied. If the heat content is determined as a function of composition x, at temperature T, we have quite generally and the heat of mixing of the liquid is obtained directly from heat-content measurements. If the temperature T lies in a two-phase region (solid-liquid) then

Jan 1, 1967

By Tim O’Neil

Tire companies have historically used the mining industry as a platform to launch new technologies. And the mining industry has been receptive to that. So, while developing its Two Piece Assembly, Goodyear noted a number of trends in the mining industry: •The global market sophistication of equipment and operations requires the packaging of products and services to provide the best return on investment. •Industry consolidation and growth have resulted in fewer, more powerful mining houses, leveraging purchasing power in the marketplace. •User productivity demands continue to drive original equipment manufacturers to develop higher pay-load equipment. •Technology needs include improved ergonomics, to reduce fatigue and increase operator productivity. •Increased laws and environmental regulation prohibit on-site whole tire disposal practices.

Jan 1, 2003

By Walter L. Finlay

The Bureau of Mines has developed prototype instruments promising to improve the ability to warn of imminent roof falls. An unusually good opportunity to test these comparatively under natural caving conditions was afforded by the forecasted caving in August 1977 of a mined-out region of the White Pine Mine. The latter's rock strata closely resemble those in many coal mines. The anticipated cave was of the competent-roof/weak-pillar type. It occurred as, and when, predicted. Automated convergence and bed separation gages agreed well with the standard manual convergence gage measurements. A micro seismic gage was found to be insensitive to the fall and may require different test conditions for effectiveness. A roof resistivity unit was tested under a separate Bureau of Mines contract. (No. H02720J7). An unplanned addition showed interesting potential.

Jan 1, 1978

By Georges J. Kipouros

Anhydrous neodymium trichlorids (NdCl3), containing ~1 weight percent neodymium oxychloride (NdOCI) was prepared by the dehydration of neodymium trichioride hexahydrate (NdC13.6H2O). Dehydration of the hexahydrate was conducted in three steps. First, the hexahydrate was slowly heated in air to about 250 °C until all the low temperature water of crystallization was removed. In the second stop, the neodymium hydroxychloride (Nd(OH)2C1) fanned in the first step was decomposed by heating under argon to 430 ° C. Finally the salt was ground and then treated with HCl gas at 330 °C until practically all of the NdOCl was converted to NdCl3.

Jan 1, 1992

By Anthony J. Miscoe, William M. McKewan, Richard C. Wang

The behavior of wire ropes used in hoisting is not well understood. In an effort to improve this understanding, the structure of round-strand wire ropes was analyzed. This report provides a generalized mathematical model that completely describes the geometry of the wires. It consists of two sets of vector equations and is valid for any round-strand wire rope. One set of equations is used to trace the paths of wires that have the form of a single helix; the other is used for the paths of double helical wires. The specific model for a 33-mm 6×19 Seale, independent wire rope core (IWRC), right regular lay wire rope was presented as an example. The paths and the geometric properties of the wires, which include the path length per lay of strand, the curvature, and the torsion, were determined from this model. The effects of strain deformation were analyzed, resulting in a system of equations for determining the structural parameters of the deformed rope. In future work, the model could be used to analyze wire ropes of different constructions so that a more scientifically based understanding of rope behavior can be established.

Jan 9, 1998

By D. C. Hogeman

Growing Greener is the single largest investment of state funds in Pennsylvania’s history, allocated to address the Commonwealth’s critical environmental concerns. Signed into law by Governor Tom Ridge on December 15, 1999, Growing Greener will enable the Department of Environmental Protection (DEP) to appropriate nearly $240 million over five years, to watershed restoration and protection, abandoned mine reclamation, and oil and gas well plugging projects. DEP has utilized these allocations in some remarkably innovative ways, as it: involves the cooperation of several state agencies, local governments, and grassroots organizations to address environmental concerns of the Commonwealth, provides funds directly to watershed groups based on locally determined decisions for local watersheds and offers a user friendly process. In three years, over $130 million in watershed restoration and improvement projects have been initiated.

Jan 1, 2002

By Peter Loehr

Full-face tunnelling machines were introduced into German coal mines 12 years ago. It was aimed to utilize these highly efficient systems to drive mine tunnels in rock so that the large demand for development work in some mines could be met. A characteristic feature of coal deposits in Germany - and particularly in the Ruhr Area - is a thick overburden strata. Access is therefore only possible through vertical shafts. A network of horizontal drivages leading from these shafts open the deposits between the different mine levels. The hardcoal-bearing formations are multi-folded and heavily tectonically stressed. Apart from a few extensive fault zones there are many single faults of different natures in the carboniferous strata. During the course of decades coal mining has penetrated to ever increasing depths. Nowadays coal is mined from depths of between 600 m and 1,200 m. The effects of ground pressure in connection with extremely varying rock strengths and high temperatures are particular difficulties which have to be overcome during drivage work. The first full-face tunnelling machines to be applied in the mines had originally bee deigned and developed for tunnelling projects. Not only the machines themselves, but also the back-up equipment had to be adapted to meet the special demands of German coal mines.

Jan 1, 1983

By L. N. Hill

The classifiers on the primary grinding circuit at Cyprus Sierrita have been upgraded from 0.66 m (26 in) diameter hydrocyclones to 0.84 m (33 in) diameter hydrocyclones. This has resulted in a 4.3 % (11 t/h) (12 standard tons/hour) increase in mill throughput while producing a flotation feed which contains 4.8% less +300 micron (48 mesh Tyler screen size) material. This reduction in flotation feed particle size has increased copper (CU) recovery by 0.8 %. Various grinding circuit relationships were evaluated. These relationships include circulating load versus throughput, horizontal versus vertical cyclone configuration, and the effect of cyclone components on performance. We conclude that the improvements achieved are due to a shift in the overflow size distribution created by a cyclone diameter more suited to our operation, and by eliminating the cyclone capacity constraint in the grinding circuit.

Jan 1, 1994