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By Lauro Calliari

Detailed geological studies using side scan sonar, bottom sampling and piston cores along the Rio Grande do Sul inner continental shelf and coastline indicate the occurrence of elongate deposits of calcareous shells fragments containing high calcium carbonate content. On the inner shelf these deposits lie at a depth between 15 and 50 meters and have been interpreted as ancient shorelines. They occupy an area of 965 km2 with a economic potential of 1 billion tons. Chemical analyses indicate a mean composition of 34.8% of calcium; 0.16 ppm of fluoride. According to the regional economy such composition make it highly recommended for a variety of uses including poultry feed and cement.

Jan 1, 1995

THOSE MARKED THUS * ARE MEMBERS, MARKED THUS ?ARE ASSOCIATES. THESE SIGNS DOUBLED INDICATE LIFE MEMBERS AND ASSOCIATES RESPECTIVELY. THE FIGURES AT THE END OF THE ADDRESS INDICATE THE YEAR OF ELECTION. HEAVY-FACED TYPE SIGNIFIES HONORARY MEMBERSHIP. *AARONS, J. BOYD, Vivian Gold Mining Co., Ltd., Harris, West. Australia. '05 *ABADIE, EMILE R., Cons. and Min. Engr., 214 Union Savings Bank Bldg., Oakland, Cal. '76 ?ABBÉ, MAX F., Prest., Abbé Engineering Co, 220 Broadway, New York, N.Y. '07 ? ABBÉ, PAULO., Secy.,Abbé Engineering Co., 220 Broadway, New York, N.Y. '07 *ABBOTT, AI ARTHUR Morococlia, Peru, So. America. '95 *ABBOTT, CLARENCE Chief EDgr., Iron Mines, Dic Tennessee Caol, Iron & R. R. Co., Bessemer, Ala. '04 *ABBOTT, JAMES W., Min. Engr: Ploche, Lincoln Co., Nev. '94 *ABE, MASAYOSHI, Prof. of Mining, Imperial University Kyoto, Japan. '05 ? ACKER, E. O'C., Supt., Treatment Dept., Bethlehem Steel Co., So. Bethlehem, Pa. '86

Jan 1, 1910

By Richard J. Mainiero, Harry C. Verakis

The Bureau of Mines has conducted research to determine whether the total elapsed delay time for blasting bituminous coal in underground mines could be safely expanded beyond the present 500-ms limitation without igniting a methane or methane-coal dust atmosphere. The results indicated that the increase of total delay from 500 to 1,000 ms had no detectable effect on safety relative to incendivity as long as permissible practices were observed in all other aspects. Research was also conducted to evaluate the safety of 18-in hole spacing for delay blasting in coal relative to misfires. For a variety of permissible explosives, misfires were observed for about 50 pct of the holes at 18-in spacing. Based on this observation, the Bureau has recommended that the new regulations prohibit hole spacings of less than 24 inches in underground coal mines. Misfires were also observed for 24-in spacing, but the number of misfires and test shots was too small to sup- port any firm conclusions.

By Y. Tao

The features of the teeter bed separator and its application in the coarse slime separation of Chengjiao coal preparation plant were discussed. The relationship between the coarse slime separation efficiency by TBS and the particle size were studied, and the influence of using TBS on dense medium consumption and oil consumption were investigated, it increased the clean coal yield and the comprehensive recovery of the whole plant, and brought huge economic benefits to Chengjiao coal preparation plant.

Jan 1, 2011

By P. Pal Roy, Ajit Raj Ostwal, M. M. Singh

Field investigations have revealed that sawdust can be used as an efficient additive to ANFO for carrying out production blasts in limestone mines. Sawdust can be used at a reasonably reduced cost without sacrificing fragmentation, muck profile and wall control. Such additives lower the detonation pressure of ANFO by acting as low-grade fuel that reacts or burns more slowly in the presence of ammonium nitrate than does fuel oil. On detonation, it eventually forms near-ideal oxygen balance that helps in liberating maximum energy to break the surrounding rock. It also forms a low-density stable mixture that helps in reducing loading density (kg/m) of explosive in the blasthole. Experiments performed at the Hirmi Limestone mine, M/s L&T, and at the Lambasta Limestone mine, M/s Jaypee Rewa Cements, showed the novel acceptance of the technique in a highly competitive market where cost reduction has been a major area of thrust.

Jan 1, 2003

By Isabella Cesario de Amaral Souza

A amostra de nefelina sienito cedida ao CETEM pela Nefelina Brasil Mineração está sendo estudada para utilização como fonte de potássio para a agricultura a partir da técnica de rochagem e de técnicas diretas de extração de potássio. Com esta finalidade, foi necessário avaliar as características físicas dessa rocha e a sua viabilidade na disponibilização do elemento de interesse. Para isto, um ensaio de liberação de potássio foi organizado, visando avaliar os parâmetros que mais influenciam nesta disponibilização como o tempo, a agitação/repouso e a proporção entre sólidos e líquidos. Foram testadas três soluções extratoras, a água deionizada e o hidróxido de sódio nas concentrações 1 e 3 mol.L-1. Conclui-se que o potencial da rocha como fonte de potássio é economicamente promissor.

Aug 16, 2017

By Douglas Morrison

By applying modern 3D numerical modelling techniques to the analysis of a pillar cascade failure in a room and pillar mine, it has been possible to simulate the collapse and develop an understanding of the role of low rock strength areas within the mine. The cascade collapse occurred in a normal strength area but would not have occurred without the influence of a low strength rockmass in one section of the mine. The numerical analysis made it possible to develop a realistic assessment of the residual pillar strength. With the introduction of regular empirical pillar performance assessments, critical pillars or groups of pillars can now be identified proactively. This has led to an aggressive extraction ratio of 90% that manages pillar failure, avoids pillar and roof collapse and prevents surface subsidence. Since the mine also has significant waste products, the use of backfill for ground support has made it possible to significantly improve the performance of strategically located pillars, and so achieve even higher extraction ratios.

Jan 1, 2003

By Y. C. Kim, I. S. Roditis, P. K. Medhi

The strongly skewed grade distributions and the need to estimate the local recoverable reserves in a selective mining environment are the two problems that ordinary kriging (OK) cannot easily handle. With the recent introduction of the non- parametric, distribution-free technique of indicator kriging (IK), the above problems can be solved. This paper describes the result of performance evaluation of IK in an open-pit gold-silver deposit. For performance evaluation, the predictions of local recoverable reserves using IK were compared with the actual reserves based on blasthole information. The IK estimator, although a bit optimistic (or overestimating), performed very well in predicting the total recoverable ounces of gold from each panel on a test bench. The OK estimator was also used to try to predict local recoverable reserves, by treating each panel as either waste or ore, depending on the panel's average grade. Under this criterion, OK was found to be quite biased and pessimistic (or underestimating).

Jan 1, 1988

By Furuyama Takashi, Mori Sukeyuki, Hara Tsuyoshi, Fukushima Yujin

In mineral processing practice, flocculation is largely established as an engineering technique of waste water treatment and the study of parameters increasing the settling velocity of particles is still of great importance to improve the process. Further investigations were made using quartz (Q89) and fluorite samples (F91) which included 58.8% and 65.8% of -2.3 µm particles respectively. In all the experiments the flocculation phenomena were observed varying the pH value of the aqueous suspension. In contrast to quartz particles (Q89) which did not flocculate for all pH values, it was, noticed that fluorite particles (F91) flocculated in the alkaline range of pH over 11. With an aqueous suspension containing equal quantities of Q89 and F91, a hetero-flocculation of particles was observed at a range of pH below 10. In this case, the maximum floc size of the hetero-flocculation was 37.0-26.2 µm This size was about three times larger than when quartz (Q84) and fluorite particles (F85) were used with 32.4% and 40.4% of -2.31 µm particles respectively. Besides, in the experiments using Q89 and F91, the maximum size of hetero-flocculated single particles was found to be 6.54 µm instead of 3.27 µm as obtained with Q84 and F85.

Jan 1, 1995

Robertson Diasol have developed a spectral gamma-gamma tool fully able to withstand borehole conditions. Spectral data is digitally recorded across 256 channels depending on energy levels of the photoelectric effect. Data processing is being developed with the objective of calibrating channel amplitudes to mineral type which will lead to a direct log of selected mineral grade as a continuous trace with depth.

Jan 1, 1990

By P. Hubert, J. P. Ildefonse, F. Qafssaoui, J. Poirier

Corrosion tests by corrosive alumina-lime slags were carried out on commercial high alumina bricks used in steel ladle linings and model refractories (with different raw materials : bauxite, andalusite, and different microstructures). Using (SEM) scanning electron microscope and (EDS) energy dispersive spectroscopy, microstructures of slag-corroded refractory interfaces were studied in detail. The monomineral and glassy phases, the composition of reaction products and chemical profiles were determined. A thermochemical analysis based on phase equilibrium diagrams has permitted to estimate the proportion and the composition of the high temperature intergranular liquid phase. These data were compared to the experimental microanalysis results. The viscosity of the high temperature liquids were calculated according to Urbain 's model and the relationship between the viscosity and the penetration of liquid phases were discussed. These theorical and experimental results were used to understand the complex phenomena of slag penetration and corrosion of andalusite and bauxite refractories at high temperature and to propose new ways of improvements for the formulation of high alumina refractories.

Jan 1, 2004

By T. G. Joseph, R. K. Soni, M. Curley

"Rapid dampening suspension is a proposed suspension design for ultra-class haulers that is intended to avoid metal-to-metal contact inside a strut and under shock loading, thus improving ride quality and ameliorating fatigue loading issues on a hauler structure. Laboratory testing has shown the ability of the proposed design to reduce the opportunity for bottoming out, that is, metal-to-metal contact between the colliding ends of oleo-pneumatic, two-piece suspension struts during the compression cycle. This paper predicts the performance of a full-size rapid dampening suspension strut by applying scaling rules to test the proposed design based on a set of field data from a Caterpillar 797B ultra-class haul truck operating in the oil sands region of the province of Alberta, Canada. The predicted performance of the suspension strut is compared to that of the original equipment manufacturer model, which was monitored on board the truck during field data collection. ¦ KEYWORDS Haul truck, Original equipment manufacturer (OEM), Rapid dampening, Strut, Suspension RÉSUMÉ La suspension à amortissement rapide est une conception de suspension proposée pour des camions de transport de catégorie ultra-class (des engins dont la charge utile dépasse les 320 tonnes métriques), visant à empêcher un contact métal sur métal à l’intérieur d’une jambe de suspension et dans des conditions de choc au chargement. Elle améliore la qualité du roulement et les problèmes de charge de fatigue sur la structure d’un camion de transport. Les essais en laboratoire ont confirmé que la concep¬tion proposée évitera au cylindre interne de heurter le cylindre externe, autrement dit empêchera le contact métal sur métal des jambes de suspension oléopneumatique en deux parties pendant le cycle de compres¬sion. Cet article prévoit la performance d’une jambe de suspension à amortissement rapide à taille réelle en appliquant les lois d’échelle afin de mettre à l’essai la conception proposée, sur la base d’une série de données de terrain relatives à un camion de transport 797B de catégorie ultra-class de Caterpillar (aujourd’hui remplacé par le nouveau modèle 797F) utilisé dans la région des sables bitumineux de la pro¬vince de l’Alberta, Canada. On compare la performance prévue de la jambe de suspension à celle du modèle du fabricant d’équipement d’origine (FEO), qui a été contrôlée à bord du tombereau pendant la collecte des données de terrain. ¦ MOTS CLÉS amortissement rapide, camion de transport, fabricant d’équipement d’origine (FEO), jambe de suspension, suspensionINTRODUCTION Research basis for the paper This paper is based on the unpublished MSc thesis work of El-Sayed (2003), Santos (2007), and Soni (2009) under the direction of Dr. Tim Joseph within the oil sands–equipment interactions program (OsEIP). OsEIP is part of the Alberta equipment–ground interactions syndicate (AEGIS) surface mining research group, School of Mining and Petroleum Engineering, University of Alberta. The aforementioned work spanned a decade of progressive studies into rapid dampening suspension systems, leading to the scale performance indications highlighted here. Although this paper uses a specific Caterpillar 797B suspension strut for field monitoring and as a basis for scale prediction of a modified rapid dampening suspension strut design, the design scaling principles used here could be applicable to any such design change consideration for an oleo-pneumatic suspension system."

Jan 1, 2019

The original work statement of this contract was entitles: 'A Accident Analysis Model for Use in Underground Coal Mines.' The contract was scheduled for a duration of 26 months and was to be in three phases: Phase I - Model Development, Phase II - Application of the Model, and Phase III - Installation, Monitoring and Evaluation of the Model. Alter three months in Phase I, it became apparent that much of the needed data for the model was nut available and could not be made available within the original study schedule. Proceeding as plumed would have resulted in a model of limited utility. Personnel from Theodore Barry and Associates and the Bureau discussed the problem in detail and mutually decided to utilize the majority of remaining funds to assist the Bureau in solving these data problems and develop a stronger ongoing capability for safety analysis within the Bureau. Both tie contractor and the bureau officials involved believed that this decision greatly enhanced the Bureau's ability to develop future accident prediction models, whose rigor would greatly exceed what was currently possible.

Jan 1, 1972

Separates of all the Technical Publications published in 1931 are available at Institute headquarters. All the papers are on file in public, university and technical libraries, and when so indicated in the list, may be found in the Transactions. Copies of these papers have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Institute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Additional copies are sold at the rate of I cent per page; minimum charge, 25 cents. Metal Mining Tech-nical Publi- Title Author Meeting TRanb. cation Volume No. and Page* 411-A.43 Ventilation at the Portovelo Mines, J. P. Harmon New York. T31, 83 Ecuador (18) Feb., 1931 425-A.44 Use of Models for the Study of Mining P. B. Bucky New York, Problems (28) Feb., 1931 Milling and Concentration 375-B.32 Ball Mill Studies, I (53) A. W. Fahrenwald New York, H. E. Lee Feb.. 1931 401-B.33 Experimental Flotation of Oxidized H. S. Gieser New York. Silver Ores (9) Feb., 1931 410-B.34 Flotation of Minor Gold in Large-scale E. S. Leaver New York, Copper Concentrators (32) J. A. Woolf Feb., 1931 414-B.35 Effect of Particle Size on Flotation A. M. Gaudin New York, (23) J. 0. Groh Feb., 1931 H. B. Henderson 416-B.36 Ball Mill Studies, 11.—Thermal A. W. Fahrenwald New York. Determinations of Ball Mill Effi- G. W. Hammar Feb., 1931 ciency (13) H. E. Lee W. W. Staley Iron and Steel Division 38QC.59 Open-hearth Steel Process as a Prob- E. R. Jette New York, C31, 80, 111 Iem in Chemical Kinetics (34) Feb., 1931 381-C.60 Thermodynamic Study of the Phasial Yap, Chu-Phay New York. Equi1ibriain the System Iron-car- Feb., 1931 bon (26) 382-(3.61 Influence of Dissolved Carbide on the Yap, Chu-Phay New York, Equilibria of the System Iron-car- Feb., 1931 ban (19) 383-C.62 Research on Blast-furnace Slags. R. S. McCaffery New York, Three papers (88) Co-workers Feb., 1931 384-C.63 Statistical Analysis of Blast-furnace K. S. McCaffery New York, C31, 60, 70 Data (13) R. G. Stephenson Feb., 1931

Jan 1, 1931

By Dick Ruby

Most miners know that Latin America's major mineral areas are in the mountains of Mexico and down the backbone of the Andes in South America. These areas comprise some of the more rugged and challenging parts of the world's geography, and the risks of doing business in these areas are just as difficult as the impressive task of extracting and processing ores. However, Latin America does contain mineral deposits, some untouched and many to be discovered, that convince venturesome people that the tremendous effort required to mine them will be worthwhile. The rewards have often been adequate in the past. Hopefully, they will be in the future. Background The safest statement that can be made about Latin America is that the "ballgame is constantly changing." Here are some examples: Chile. Under President Frei in the 1960s, Chile welcomed foreign mining interests, even though the government was acquiring significant ownership interests in the big copper properties. Then, under Allende in the 1970s, the big mines were taken over and compensation was denied on various grounds including the allegation that extraordinary profits had been made that should have been taxed. After Allende, an about-face was made in policy; former owners of the expropriated mines received some compensation and new foreign investment was seriously welcomed. Many major companies announced intentions to return to Chile. Some have. Peru. After a military takeover in 1968, Southern Peru Copper

Jan 7, 1983

Although the 'exi'stence of bauxite in Australia has been known for many years it is only recently that exploitation has commenced.. of the two most' important` deposits, strangely at almost diagonally opposite tips of the continent. Recognition of the importance. of the bauxite in the South/West corner came about initially through the efforts of a well-known Australian mining company which,` with some outside financial help, tackled the early exploration with commendable foresight and courage.

Jan 1, 1964

By Waldo Valderrama, Luis Magne, Paola Grandela

The effect of liner shape on power consumption was studied in a small laboratory mill under various operating conditions. It was found that the angle subtended between the lifter front face and the face in contact with the mill case has the most significant influence. The increasing height of lifter reduced power consumption, whereas the lifter spacing did not show any influence. The effect of height is less relevant at lower front angles. Highest power consumption is achieved with a 45" front angle. A comparison of cylinders and balls under identical conditions gives higher power consumption for ball charges. The data does suggest that, for maximum power draw, slip in the outer layers of the charge and the early recirculation of energy to the mill case should be avoided. Both factors prevent an efficient energy transfer to the mill charge.

Jan 1, 1995

By Melina Gamis da Silva

Em um trabalho anterior [1], as temperaturas de processamento aplicadas na laminação de tiras a quente, LTQ, da CSN foram investigados para algumas classes de aços microligados ao Nb. Os resultados deste trabalho mostraram a possibilidade da redução da temperatura de reaquecimento utilizada para esses aços refletindo em possibilidades de melhoria de produtividade. No trabalho atual, o impacto dessas mudanças na microestrutura obtida de LTQ foi investigado com mais profundidade, utilizando um software desenvolvido para prever a evolução da microestrutura em termos das frações recristalizadas, das distribuições de tamanhos de grãos e do comportamento das tensões médias de escoamento, TME.

Oct 30, 2017

By K. Osseo-Asare

Aqueous stability diagrams (25°C) are presented for the systems M-H2O and M-Oxalate-H2O where M=Sm, Nd, Co, and Fe. With the aid of these diagrams (i.e., Eh-pH and log[Metal]- log[Oxalate]), the solution-chemical constraints on metal dissolution and precipitation are identified. By comparing the corresponding stability diagrams, conceptual flowsheets are developed for metal recovery from Sm-Co and Nd-Fe-B magnet scrap.

Jan 1, 1997

By Ali Bouafia

Five full-scale horizontal loading tests of piles carried out by the LCPC in France are interpreted in order to analyse P-Y load-transfer curves. The experimental piles are either bored or jacked into quite homogenous sandy soils and instrumented by strain gauges for measuring bending moments along the pile. Successive differentiation and integration of bending moment profiles have led to derive respectively lateral soil reaction and displacements then to construct the load-transfer P-Y curves. The initial horizontal lateral reaction modulus was derived from these curves and shows linear variation with depth in accordance with Gibson soils profiles. P-Y curves are validated by back-computation of the pile on the basis de these curves and the horizontal reaction modulus was compared to the recommendations frequently used in pile design practice.

Jan 1, 2002