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The Wednesday morning session was called to order by President Geiger at 9:30 a.m. He asked Stan Shubart to conduct the meeting. Stan thanked Loren Linville and Bill Grant for the excellent job they did in their assignments. He called on John Schmidt, Chairman of the Auditing Committee, to report on the financial statement of the treasurer. Mr. Schmidt read the data and asked for its approval. A motion was made, seconded and approved. Stan called on Joseph Berta, Chairman of the Resolutions Committee, who submitted the following resolutions: (1) RESOLVED: Whereas, in the year since the last convention of the Rocky Mountain Coal Mining Institute, the Institute and the coal mining industry generally have suffered the loss through death of the services of: Clement Audin, Jr. C. Herbert Clendenin Donald Haske William H. Hays M. J. Keenan Fred W. Koelling James Mecca Neil Robinson C. M. Shott

Jan 1, 1974

By H. V. Scotland

Lafarge Corporation's Texas Quarry, in Baltimore MD, achieved a substantial expansion of pit reserves by removing an inactive underground mine. The daylighting program, designed, and completed in 1997, open pit mined more than400 meters of room and pillar workings which were originally developed to recover high brightness Calcium Carbonate. The project proved to be a challenge throughout its course as the pit plan was modified and successful daylighting techniques were developed to remove the mine without adversely affecting the safety of the operation, quality of the stone recovered, or negatively impacting the surrounding community. The design parameters and techniques developed and implemented at Texas may prove of interest to other operators as they are faced with daylighting opportunities. This article will detail the challenges we faced and the solutions which made the project a success.

Jan 1, 1999

By AIME AIME

AT the meeting of the Iron and Steel Division at Cleveland, Sept. 10-12, the morning of Thursday, Sept. 12, has been set aside for an excursion to visit the ore docks, blast furnaces, and steel plants. A special train, made available through the courtesy of Appleton Cleveland, general superintendent of the Pennsylvania Railroad, will leave the siding near the Auditorium at 8.35 a. m. The trip will be free, but tickets must be' obtained in advance at the booths for registration for excursions at the Auditorium. An hour will be spent at the docks, an hour at the Central blast furnaces, and two hours at the Cuyahoga works of the American Steel and Wire Co. A buffet luncheon will be served, with the compliments of the Pennsylvania Railroad Co., on board the train en route. At the Tuesday morning session, Sept. 10, a motion picture showing the operations in making wrought iron by the Aston process will be shown for the first time.

Jan 1, 1929

By R. M. Wheeler

For years the blasting industry has recognized eight milliseconds as the minimum delay time interval required between charges in order for them to be considered to fire independently of each other. However, computer analyses of seismic recordings made of several surface mine blasts reveals that this time interval may not always be sufficient for adequate vibration separation to occur. In some situations a combination of short delay periods and low frequency vibrations can result in waveform reinforcement. Various analyses of seismic recordings obtained from single hole detonations can be used to predict delay intervals that may enhance or reduce blast vibration effects.

Jan 1, 1987

By M. F. Dibble

The technology available for mining of underwater mineral resources such as placers and phosphorite, typically occurring with variable amounts of overburden, has remained largely unchanged for decades. The traditional bucket ladder dredge with maximum digging depth of 48 m and monthly capacities about 500,000 m3 still reins as the only heavy duty mining system capable of working the tough materials characteristic of heavy metal placers. Attempts at adapting the bucket wheel cutter-suction dredge to these severe conditions have not yet been successful except in moving small volumes from shallow depths. High capital cost (20-30 million U.S. dollars), high cost of overburden removable, and turbidity generation for the bucket ladder are often significant negative factors in mining operations where this system remains the only viable alternative. The Japanese continue to advance the technology of their submersible dredge pump system powered by specially adapted, direct drive electric motors. Present systems are designed primarily for working surficial deposits of aggregate to depths as great as 90 meters, the pump suspended by cable from a surface vessel with an eductor pipe leading from the pump to the vessel. Such a system may prove adaptable to a variety of surficial deposits including phosphorite, shell and heavy minerals in addition to aggregate. However promising for the exploitation of surficial deposits, little advantage can be expected for the deeper buried and more difficult deposits.

Jan 1, 1986

Colorado Geological Survey, Boulder, Colo. R D George, State Geologist. The following publications of the Survey may be obtained as long as the supply lasts, at the indicated price. Bulletin 3, Geology and ore deposits of the Alma district (1910), 25 cents, 4, Geology and ore deposits of the Monarch and Tomichi districts, Chaffee and Gunnison counties (1912), can be had together with 5, pt 1, Geology of the Rabbit Ears region and pt. 2, Permian or " Permo-Carbonif erous " of the Eastern Foothills of the Rocky Mountains in Colorado, for 50 cents; 7, Bibliography of Colorado geology and mining literature (1914), 25 cents, 8, The clays of eastern Colorado (1915), 25 cents, 9, Geology and ore deposits of Bonanza district (1915), 25 cents, 10, Geology and ore deposits of Gold Brick district (1916), 25 cents, 13, Geology and ore deposits of the Platoro-Summitville district (1917), 25 cents; 14, Molybdenum deposits of Colorado (1919), 25 cents; 15, Manganese deposits of Colorado (1919), 25 cents (14 and 15 in one volume, 35 cents); 17, Twin Lakes district (1921), 25 cents. Bulletin 18, Fluorspar deposits of Colorado (1920), 25 cents, 21, The geology of the Ward region, Boulder County (1921), 50 cents, 22, Mineral deposits of the Western Slope (1921), 25 cents, 24, Some anticlines of western Colorado (1924), 50 cents; 27 (in three parts) pt 3, Geology of parts of Las Animas, Otero and

Jan 1, 1933

By John C. Stankus

The success of cable bolts for mine ground control have been well documented in papers presented at this conference too numerous to reference. Cable bolts have proven effective over the years mainly utilized in the form of supplemental support. Some limited work has been conducted on the use of cable bolts as primary support This work has been mainly confined to the West and the bolts utilized were of a non- tensioned type MSHA requirements for primary support have been that the bolt system he tensioned or if non-tensioned, then fully encapsulated with resin. Many operators are now interested in using cable bolts as primary support Further, despite the enormous success of cable bolts, there have been questions raised about the longevity and corrosion characteristics of the cable itself particularly for long tern applications. To improve the corrosion characteristics of cable bolts, galvanized cable has been used for some applications However. although improving the corrosion resistance of cable, galvanized cable for mine ground control does not provide complete protection under certain types of situations and mine environments. Realizing a need for a cable bolt that can be used for primary support and provides consistent installed tension, complete corrosion protection, and a fast installation, Keystone Mining Services. LLC (KMS), an affiliate of Jennmar Corporation, has developed the INSTáL CableOx system. This paper will detail the development and specifics of this system including two underground case studies

Jan 1, 2000

By Stephen C. Tadolini

Cable supports offer several advantages over traditional secondary support methods. Cable supports enhance stress redistribution to pillars and gob areas, minimize or eliminate timbers and cribs which reduce ventilation capabilities, eradicate material handling injuries related to the placement of crib supports, and provide a cost-effective alternative to secondary support. The U.S. Bureau of Mines has designed and installed cable supports to improve the stability of tailgate entries in an underground western coal mine. Two entries closest to the Iongwall panel were solely supported with high-strength cables installed with cement grout. Basically, with modifications in the intersections, 360 ft of roadway nearest the longwall panel was supported with two rows of 22-ft-long cables installed on a 7-ft spacing. Approximately 250 ft of a second bleeder entry was supported with two rows of 16-ft¬long cables installed on a 7-ft spacing. Individual cable loads were monitored with hydraulic U-cells and pressure pads. The roof behavior was simultaneously monitored with differential magnetic sag stations and closure meters on 25-ft spacing during longwall panel retreat to evaluate the response of the immediate and main roofs. Cable supported gateroads appear to be a viable alternative in secondary support when compared to wood timbers and cribs. This paper describes the theory, application, and advantages of cable supports and presents the results of the mine measurements made to assess the cable performance during the retreat process of longwall mining.

Jan 1, 1993

By D. A. Kramer

Seawater and natural brines accounted for about 51percent of U.S. magnesium compounds production during 2004. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Mining and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

Jan 1, 2005

By J. P. Zannaras

If we assume that testing of the model started at time C, that time t2 was the instant at which the elastic limit of the material was passed at the points of the maximum stress, and that at time t3 the failure of the model was completed as shown in the typical photograph (Fig. 1), then actually the photograph shows the final results of what took place between time t2 and t3. By the principle of similitude all conclusions drawn from the behavior of the model were applicable and valid for actual mine roofs up to the time t, after time t, motions and friction came into play during the destruction of the model. The events between t2 and t3 and the photograph itself are not representative of the events expected in an actual mine roof unless corrections imposed by the principle of similitude are made.

Dec 1, 1956

By R. D. MacEchern, M. C. Rockwell

"This paper describes the research and tests carried out to recover the readily available barite from the tailings produced by the Nystone Chemical Ltd. operation at Debert, N.S. The tailings comprised 70-80% of the original feed and contained about 20-25% Baso4 .The objective of the research, undertaken during 1982, was to produce a barite concentrate which would meet the American Petroleum Institute (API) barite requirements for use in drilling mud. Samples from the tailings pond were examined and analysed to determine the tailings characteristics.Preliminary test work was performed on the tailings samples using a Haultain Superpanner, Wilfley tables and Humphrey's spirals. The grade of the barite concentrate retrieved did not satisfy the API barite requirements.The fineness of the tailings and the fact that approximately 80% of the barite was contained in the -200 mesh (0.074 mm) size fractions, indicated that flotation of barite from the tailings might be successful."

Jan 1, 1984

By Rodrigo Craig Cerello

The Brazilian economy has always presented a strong correlation with the mineral activity. Since colonization days, due to the territorial expansion caused by the explorers search for gold, mining in Brazil became a basic sector of national economy. Currently, the Brazilian mineral sector¹ estimates a 550% production increment (Figure 1A) in the last 10 years, reaching the US$ 50 billion value, reflecting the increased global demand for raw materials from mineral origin. According to the Brazilian Constitution², mineral resources belong to the Federal State and, consequently, their exploitation must be authorized, under penalty of engendering federal crime. Furthermore, activities of this nature are prone to cause environmental degradation such as, but not limited to, deforestation, pollution, soil deterioration and water contamination. The GPEMA represents the forensics group of the Brazilian Federal Police responsible for the technical analysis of traces related to crimes against the environment and consequently, illegal mining cases.

Aug 1, 2013

By Dunn P. G

The copper ore reserves at the Chuquicamata mine were re-estimated during March to June 1994, as part of a comprehensive audit of the mine's overall short- and long-term planning. The basic principles essential to all ore reserve estimates were implemented viz: 1. A detailed study of the geology, in this case particularly of the orientations of structural features of copper mineralisation and the subdivision of the orebody into geologically homogeneous sections, 2. the use of both drillhole and blasthole data sets, 3. statistical and geostatistical analyses of both data sets to model anisotropic spatial structures for all the geologically homogeneous sections, 4. block kriging using both data sets individually; and 5. a comprehensive validation of the block valuations to confirm the absence of global and conditional biases and to quantify the actual improvement achieved in the overall quality of the estimates compared to those executed on earlier techniques.

Jan 1, 1995

The original design of the Bougainville Copper Limited (BCL) concentrator took cognisance of the constraints imposed by the topography, the need to minimise capital cost, and the need to allow for plant expansion which, it was known, would be necessary to maintain copper and gold production as head grades declined.At the same time as spare slots have been taken up with additional equipment, technological innovations have been embraced whenever there appeared to be a chance of improving the productivity ofexisting equipment, or replacing it with a more efficient alternative.There are many examples of this in the BCL concentrator in the areas of process control, process design, instrumentation, materials handling, equipment design and wear part technology.Current process developments also pursue the latest technology. The development of the Omnicone crusher, flotation control, tailings water reclamation, and the variable speed gearless drive on the No. 13 mill are prime examples.

Jan 1, 1986

By R. D. Doepker, P. L. Drake

The dissolution of metals from various metal- mine tailings has been studied through a series of submerged tailings batch tests at US Bureau of Mines laboratories. Tailings selected for this study included both reactive (as determined by column leaching studies) and benign tailings. Metal mobilization in aerated (97% saturated with oxygen) samples appeared to be consistently greater than metal dissolution from stagnant (79% or 70% saturated with oxygen) waters. In the early weeks of the study, sulfate concentrations increased with solid-liquid contact time, while calcium dissolution remained early constant. Metal concentrations varied in relation to solid-liquid contact time and aeration. Leachate pH appeared to be nearly independent of solid-liquid contact time for basic tailings. Reactive tailings having both a submerged and a surface component demonstrated increased metal mobility.

Jan 1, 1991

By C. H. L. Bastos

A physical and chemical characterization study was carried out on 483 kaolin samples from 2.9 km2area at the Para Pigmentos mine along the Capim river, northern Brazil. The samples obtained from cores, drilled with regular spacing of 100 m, were evaluated using grit percentage, particle size distribution (psd), brightness, leachability, magnetic response and viscosity. These parameters were correlated with each process step in the plant and also the physical and chemical properties of the ore and finished product. Cluster analysis was performed and four main groups of kaolin were identified. These were then related to their performance at the various process steps and the quality of the initial product. These groups are well defined by plotting grit X “psd” and TiO2x “psd” in scatter plots.

Jan 1, 2004

By C. L. Karr, E. J. Gentry

Researchers at the U. S. Bureau of Mines have developed a control algorithm to efficiently manipulate chaotic systems. The control, based on both fuzzy logic and genetic algorithms, prescribes actions that drive the chaotic system to acceptable regions of state space. The use of fuzzy logic enables a person who has limited experience with a chaotic system to establish a set of rules for manipulating the problem environment, and a set of membership functions that define terms used in the rule-set. Genetic algorithms are search algorithms based on natural genetics, and are used in the control algorithm to select membership functions that provide for a suitable level of control. The Bureau-developed algorithm controls the computer simulation of a ball bouncing on an oscillating table, a system that exhibits chaotic behavior.

Jan 1, 1993

By Austin Park

More metal at a lower profit continued to be demanded from the mining industry during 1969. Correspondence with U.S. and Canadian mining districts and a study of the mining literature indicate that, a large majority of the mines are keeping pace and rising to the challenge. Continued research and better understanding of pneumatically applied concrete for roof and wall support was of top interest. Many mines are changing mining methods for the adaptation of load-haul-dump units. The most recent adaptation being the use of these units in cut- and-fill stoping and in various types of development headings. Boring methods and use of two- or three- boom drilling jumbos mounted on rubber tires for versatility continues to be the favorite approach to the demand for rapid excavation.

Jan 1, 1970

By P. Somasundaran, C. C. Harris

The power consumption of stirred-media mills was studied using an approach developed from work on stirred reactors. Evaluated were the relationships of factors such as stirring speed and impeller and tank dimensions on the torque required to rotate disc and pin impellers immersed in dense particulate media. Data collected under carious experimental conditions were analyzed. The results were summarized and presented in the form of characteristic plots, general equations and dimensionless group correlations involving power and modified Reynolds numbers. Special attention was directed towards the rheological properties of the media, which was considered a non-Newtonian liquid, and hence the equation of power-law liquids was employed. A procedure for estimating the parameters of effective viscosity and scale-up guidelines (with respect to power consumption) are proposed.

Jan 1, 1996

By D. Y. Geng, S. S. Peng

Surface subsidence of two longwall panels, one with a private residence and the other with an arch bridge, was monitored over a period of 1 to 1' ½ years. Surface subsidence data were analyzed in terms of zone of advance influence and delay angle of maximum subsidence velocity. The variational characteristics of both features coincide with the periodic weighting at the advancing longwall face. Surface heaving in the subsidence process can also be attributed to periodic weighting. It was found that residential damages occurred when subsidence velocity exceeded 4.5 mm/day (0.15 ft/day). The effects of locating structures on the panel center and near the gob edges are illustrated. The effect of mining on ground water was also discussed. Finally, methods of reducing structural damages are recommended.

Jan 1, 1984