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The Particulate Mineralogy Unit has been established at the College Park, Maryland, Metallurgy Research Center. The Particulate Mineralogy Unit will have the responsibility within the Bureau of Mines for the characterization of particulate minerals which have potential for adverse environmental effects. The Unit will provide a focal point for identifying particulates in connection with environmental problems related to the activities of agencies such as OSHA, HEW, EPA, and MESA. The Particulate Mineralogy Unit is seeking to clarify the ambiguities surrounding the mineralogy of and terminology used for asbestiform minerals and other mineral particles. The Unit?s investigations of the morphology, composition, and structure of asbestiform minerals and their nonasbestos analogs have made its members recognized experts in this field. The information which it develops on the characterization of asbestos and other particulate mineral forms such as silica should provide a technically rational basis for decisions by regulatory agencies. Those desiring further information, contact Dr. W. J. Campbell, Program Coordinator, College Park Metallurgy Research Center, College Park, MD 20740, telephone: 301-344-4014. ALUMINUM: For over a month, domestic producers have priced 99.5 percent grade primary aluminum ingot at 48¢ per pound. In the same period, merchants raised ingot quotes by 1.5¢-2.5¢ to a range approaching 44¢-47¢ per pound.

Jan 1, 1976

By Manuel Villanueva Bullón

El presente trabajo describe la factibilidad del programa por computadora en los proyectos de minado no masivo a cielo abierto. Dicho programa permite calcular la cubicación del mineral como del material estéril para los tres ángulos de talud diferentes, as leyes de veta sin diluir y las relaciones desmonte-mineral para cada sección y zona explotada. En este sentido, la utilización de la computadora ahorra tiempo en los cálculos, aprovechándolo en beneficio del planeamiento de operaciones mineras.

Nov 20, 1978

By J. Zegarra

"Si bien el anhidrido sulfuroso es considerado como un contaminante atmosférico, puede ser utilizado en la concentración de minerales por flotación a través del reemplazo del NaCN/CaO. En ese sentido, el presente texto señala la aplicación de este reactivo en el proceso de flotación, así también como se presenta los trabajos realizados a escala de laboratorio con el objeto de determinar su aplicación a la flotación selectiva directa de mineralessulfurados y en el mejoramiento del grado de concentrados de zinc. "

Jul 1, 1976

By Juan Ramírez L

El presente texto describe la aplicación del método de evaluación de volquetes en minería de cielo abierto, donde se considere las variables que influyen en la operación y la factiblidad del mísmo a posteriori. Para ello, se han desarrollado dos programas para calculadora HP-41CV, que dado su carácter voluble y poder de resolución, se adecúan a este tipo de trabajo. En este sentido, el cálculo del equipo de acarreo conlleva el cálculo del mineral a extraer, cálculo del stripping, proyección de avances, velocidades y ciclos y número de volquetes necesarios para movilizar el tonelaje proyectado.

Nov 8, 1984

By IPMI Educational and Scientific Foundation

It is with great pleasure that we announce the availability of this fourth issue of the IPMI Journal, a publication of the International Precious Metals Educational and Scientific Foundation. This digital peer reviewed publication has been created as a vehicle for the sharing of technical information related to the science and technology of precious metals. Since 1976, the International Precious Metals Institute has championed the exchange of information of critical importance to the precious metals scientific and commercial communities through its various communications vehicles. This has included instructional videos, annual conference symposia, special topic committee meetings, regional seminars, and professional and student achievement awards. Due to the breadth of important topics related to all aspects of precious metals, it has been the vision of the IPMI to provide a publication available to the general public that would become a key source of pertinent topics containing high quality publications by experts in their fields of study. Historically, the IPMI has attracted world renowned experts in many fields (including Nobel Laureates Henry Taube, Ei-ishi Negishi, Robert Grubs, Professor Ben Feringa, and David MacMillan) in the dissemination of discoveries, inventions, and industry proven practices. Such information has a total value greater than the sum of its parts as seemingly unrelated innovations from distinct focus areas can be adapted to solve problems. Because of this important characteristic of information exchange, we have decided to create a digital journal, available to the general public, that will not only communicate state of the art discoveries and sound practices, but will also review historical communications from the IPMI’s archives that have value and use even in today’s environment. On behalf of the members and leaders of the IPMI, we hope you will find value in this new publication.

Dec 1, 2022

By L. C. IlsLey

"This paper is intended for State mining inspectors, safety engineers of mining companies, and others interested in electrical safety inspection in mines, It presents the important points that should be watched by inspectors, and briefly reviews the work of the Bureau of Mines in the testing of electrical apparatus or equipment to determine their permissibility for use in gaseous coal mines.Important Points in Inspecting Mine Electrical Installations or Equipment.The following questions are intended as suggestions to a safety inspector who may not have been specially trained in looking for defects in installations or in the maintenance of electrical equipment:1.,Is there someone in charge of electrical equipment who is fitted for this position by ability, training and experience?2.,Is a systematic recorded inspection of electrical equipment made at least once each month?3.,Is a plan map of the mine kept showing all permanently installed electrical machinery and apparatus, including cables, conductors light etc.?4.,Are there instructions for resuscitation from electric shock posted in each surface and underground electrical station, also at the entrance of the mine and in the first aid station and are employees working on electrical equipment trained to apply these instructions in case of accident?"

Nov 1, 1923

By ERNEST F. . SURCEIARD

work have been published from time to time by the Survey.' A detailed report on the Birmingham district, with maps, has been completed, and will be published within the next year." In the following paper it is aimed to present only an outline of the geologic relations of the ores, since the Appalachian geology of Alabama has been discussed by many previous writers, but to describe rather fully the ore of the Birmingham district, and to discuss its relations and probable extent. IT. OUTLINE OF THE GEOLOGY. 1. Stratigraphy. The pre-Pennsylvanians rocks exposed in and along the borders of the valley-regions of Alabama, range from middle Cambrian to Mississippian (Lower Carboniferous), and at the SW. extremities of the valleys these rocks are overlain by coastal-plain deposits of Cretaceous and Tertiary age. A generalized section of the pre-Pennsylvanian Paleozoic rocks for the valley-regions is given in Table I. TABLE I.-Section of Pre-Pennsylvanian Paleozoic Rocks in Valley-Regions of Alabama. System. Formation and character. Thickness. Ft. Shale and sandstone 300 to 2,200 Carboniferous (Mississippian- Limestone and shale 300 to 800) I Sandstone and shale 50 to 200 1 Fort Payne chert and limestone 100 to 300 Devonian Chattanooga shale 0 to 30 Silurian Clinton (" Rockwood ") shale, sand¬ stone, and iron-ore 200 to 700 Ordovician Chickamauga ("Trenton") limestone.. 200 to 800 Cambro-Ordovician Knox dolomite and chert 1 2,200 to 2,700 basal dolomite 500 to 600 Cambrian Conasauga shale and limestone 1,000" to 1,500 - I a Base not. exposed.

Nov 1, 1908

By John R. Bradley

The object of this paper is to survey and analyze the bearing of economic nationalism, competitive sources of energy, and technologic developments on international trade in coal with especial reference to the competitive position of the leading coal-exporting countries in the Italian market, the largest in the Mediterranean region, and the Brazilian market, the second largest in Latin America. The political, economic, and financial disturbances caused mainly by the World War have resulted in an amazing situation. Especially since 1930 have conditions been complicated.

Jan 1, 1936

By Christopher J. Vise

Although production operations at mines, representing the extraction and removal of the mined material, often appear to receive the greatest amount of attention, the emphasis given to auxiliary operations is continually increasing. This is due to the changing economic, social, and environmental climate in which modern mines must operate. Auxiliary operations can best be described as those activities that are not directly related to the extraction and removal of the mined material, but must receive proper attention if recovery is to take place in a safe, efficient, and socially responsible manner. In fact, certain mining auxiliary operations, such as strata control and ventilation, are considered to be of such importance that they warrant separate sections in this Handbook. Judging from a mine-personnel standpoint, it is not uncommon for a mine to hire the same number or more individuals responsible for auxiliary operations as the number assigned to production.

Jan 1, 2008

By Louis J. Sousa

In November 1989, the U.S. Bureau of Mines sponsored a 2-day conference to stimulate thinking and discussion about changing materials technologies and implications for the Government's materials information programs. On the first day of the conference, speakers provided overviews of developments occurring in each of the major materials groups. Emerging technological developments, applications, economic and national defense significance, intermaterial competition, and potential market growth in advanced plastics, polymer composites, ceramics, metals, and electronic materials were described. In general, the speakers forecast advanced materials market growth rates in excess of overall gross national product (GNP) though high costs will tend to limit growth outside of aerospace, defense, electronics, medical equipment, and other typically high value-added businesses. On the second day, a wide range of speakers representing several facets of the materials community described how advances in materials technology are creating a need for new types of data, statistics, information, and analysis. Reflecting the speakers' broad range of organizational, professional, and personal perspectives, an array of information needs was identified. Most requirements, however, seemed to fall into one of five major categories: Federal materials research activities, material standards, market and economic information, health and safety, and public policy.

Jan 1, 1990

By H. Kenworthy

Sulfide-ore concentrates containing cobalt, nickel, copper, lead, and iron from the operations of the National Lead Co. at. Fredericktown, Mo., were treated successfully on a laboratory scale to recover more than 90 percent of the cobalt, nickel, and copper. A cobalt -nickel-bearing, lead-copper matte., produced by the St. Joseph Lead Co. at Herculaneum, Mo., was treated to produce a lead-zinc fume, a copper sulfide concentrate, and a cobalt nickel-iron product, netting a recovery of over 75 percent of the cobalt and about 90 percent of the nickel and copper. National Lead Co. bulk concentrates were chlorinated with gaseous chlorine to form anhydrous metal chlorides and sulfur chlorides, sulfur chlorides were recovered by distillation, a high percentage of the ferric chloride was converted to ferric oxide, and the chlorinated residual metals were extracted with water. Metal ions were removed from leach liquors by pH-controlled fractional precipitation as hydroxides. Cobalt solutions "were prepared from cobaltic hydroxide, and procedures were developed to remove contaminating metal ions. Purified cobalt solutions were employed as electrolytes for deposition of high-purity cobalt.

Jan 1, 1953

By Valeria Romina Stricker

Acerbrag es una empresa Argentina siderúrgica de 50 años de trayectoria, desde el año 2007 pertenece al grupo Votorantim de origen Brasilero. Se dedica a la elaboración de aceros largos para la construcción. La planta industrial cuenta con un proceso de acería integrado, horno eléctrico, horno cuchara y máquina de colada continua. La materia prima es 100% chatarra, característica que la diferencia del resto de las acerías del país. Debido a esto el enfoque principal de este proyecto es reducir el costo de fabricación mediante un “empobrecimiento” de la carga metálica a partir de la flexibilización de los límites de especificación. Esto implica un mayor control del desempeño de los procesos a fin de detectar posibles desvíos, para ello fue necesario implementar la utilización de herramientas estadísticas y gráficas para su monitoreo. La modificación en el mix de fabricación no muestra una alteración significativa en la composición química y propiedades mecánicas de los productos terminados, situación favorable para la continuidad del proyecto. Se observa además, de la reducción de costo esperada, una ventaja en la operación del patio de chatarra y el proceso de acería y en la utilización de chatarras con altos niveles de residuales tales como Cr – Ni.

Aug 16, 2017

By Giorgio De Tomi

La industria del cemento se caracteriza por una alta inversión en tecnologías de procesamiento, principalmente en la fábrica de producción de cemento. Dicha tecnología incluye el monitoreo continuo y la mezcla de las materias primas que se obtienen de la cantera y también de fuentes externas. Por ello, la inversión es necesaria para producir un producto final que sea fácil de trabajar, con buena resistencia y excelente durabilidad a largo plazo. Para satisfacer estos requerimientos el rango de variación de los minerales constituyentes del cemento debe ser muy ajustado. En ese sentido, el presente texto plantea una solución integrada para el control de la calidad basada en un profundo conocimiento geológico de la cantera de caliza, lo que permite programar las mezclas de materias primas de acuerdo a los requerimientos de la planta.

Aug 25, 2002

By J. Mantilla, J. Calizaya, J. Frisancho

"La mina Tantahuatay; es un deposito epitermal de alta sulfuración Au-Ag, en perforaciones recientes de extensión por sulfuros, se ha determinado zonas de Skarn al NE del tajo Tantahuatay 2, ubicado políticamente Chugur, Cajamarca, Perú. Los trabajos de perforación 2016, nos han permitido reconocer nuevos cuerpos mineralizados asociados a zonas de Skarn, con leyes de (0.30 g/t Au y 0.4% Cu), emplazados en las formaciones Chulec (calizas), Inca (sedimentos), Farrat (cuarcitas). Los ensamble de alteración analizados son Yeso, Clorita, Epidota, Paragonita, algunos de estos minerales poseen una concentración anómala de REE. Indicativos de una gradación sistema alta sulfuración a Skarn."

May 1, 2008

By P Mesquita, A Nolan

Using a scientific-principled definition of global socio-ecological sustainability can be a useful basis for planning precious and base metal mining projects. The mining industry faces key challenges of; viability of the minerals industry; the control, use and management of land; national and local socio-economic development; environmental management; materials stewardship; and access to information. Using a framework for strategic sustainable development to assess the current reality of mine project development has resulted in identifying areas of strength and opportunities for improvement between current best practices and a desired vision of sustainability constrained by science based principles. These gaps indicate opportunities to strengthen current strategies, tools, and actions with a deeper understanding of socio-ecologic systems and a first-order, principled definition of sustainability, enabling success in moving towards achieving a sustainable society, ie sustainability. Evaluation of mine project development and their impacts on ecological and social systems using a systems perspective which recognises the underlying principles of operation, delays, feedback loops and response to change highlight specific opportunities to create value for social, economic and ecologic systems. Envisioning this future for mining projects within a sustainable society can be done by evaluating their development and operations guided by the sustainability principles. Performance indicators play a key role in measuring progress towards achieving sustainability goals yet it is necessary to consider whether indicators capture the whole systems perspective. Connected to this broader view, indicators can contribute much value to the mining industryÆs sustainability journey. This paper examines how current processes for mining projects can be developed using a whole systems perspective and measured using holistically designed performance indicators.

Jan 1, 2009

By Henry Louis

THE work performed by the Royal Commission on Mining Subsidence is likely to prove of permanent value, less perhaps for the conclusions it has reached and for the recommendations it has based upon these than for the admirable exposition which it affords of the law concerning mining subsidence and of the legal status of the person who has suffered damage by reason of such subsidence, as also of him whose working has caused the damage. The Commission was appointed by Royal Warrant in the middle of 1925 and delivered its final report in the middle of 1927. The terms of reference to the Commission were as follows: "To consider the operation of the law relating to the support of the surface of the land, and of buildings or works on or under the surface, by underlying or adjacent minerals; to enquire into the extent and gravity of the damage caused by subsidence owing to the extraction of minerals and the incidence of the resulting liability; and to report what steps should be taken, by legislation or otherwise, to remedy, equitably to all persons concerned, any defects or hardships that may be found to arise in existing conditions."

Jan 1, 1929

By Robert Lee, Jeff Corace, Rob Cyr

Blasting in the heart of the historic Byward Market District of Canada’s capital, Ottawa, presents a unique set of challenges. The obvious difficulties arising on projects requiring blasting within 3 m (10 ft) of 125 year old buildings in various states of disrepair have been encountered and successfully dealt with countless times before. The complexities increase exponentially when tenuous property boundaries, unknown structural details, litigious histories and the need for encroachment agreements lead to individuals with competing interests all able to impact the same operation. Blasting on three projects in the Market was started in early 2005 after months of negotiation. Ultimately, the potential for the projects to proceed hinged on the ability to successfully disseminate blast data to the various stakeholders. As part of the agreements drawn up, property owners demanded immediate notification of the measured vibration levels with contract provisions including clauses such that any exceedance of the USBM criteria immediately triggered project shut down and complete blasting program redesign, and approval by all parties. With stakeholders located in various cities and, in some instances, on various continents, a conventional attended monitoring strategy would not satisfy the requirements. In response to the critical reporting need, Explotech Engineering Ltd. installed unattended monitoring stations around the sites, all incorporating wireless telemetry. After each blast, data was automatically transferred from the monitoring stations to a web-linked server via the wireless network, where it was immediately available to project stakeholders through a password protected website. The solution required a unique blend of data acquisition, telemetry, database, and security technologies, all married to produce a reliable system that was easy to maintain and use. While these types of systems were originally developed for use as permanent monitoring networks in operating mines and quarries, monitoring professionals are increasingly benefiting from the technology on temporary building projects that have typically been the realm of attended monitoring strategies. Globally, this has emerged as a solution to provide more timely access to data for stakeholders, and to minimize the legal exposure from multiple violations of vibration limits. As this trend is likely to continue, the regulated vibration control industry is likely to see a continued shift in technology development to leverage wireless networks and the Internet to continue to improve data transfer, archiving and distribution.

Jan 1, 2006

Trans. No. Place Date Vol. Page 1. Wilkes-Barre Pa......May.71 1 3 2. Bethlehem, Pa.........Aug., '71 I 10 3. Troy, N.Y............Nov..: 71 1 13 4. Philadelphia, Pa........Feb., 72.. 1 17 5. New York. N. Y.*......May, '72.. 1 20 6. Pittsburgh. Pa.........Oct..' 72.. 1 25 7. Boston, Mesa..........Feb., '73.. 1 28 8. Philadelhia, Pa.*......May, '73.. 2 3 9. Easton, is............Oct..' 73.. 2 7 10. New York, N. Y.......Feb..' 74 . . 2 11 11. St. Louie. Mo.*........May,' 74 . . 3 3 12. Hazleton, Pa...........Oct., '74.. 3 8 13. New Haven Conn......Feb., '75.. 3 15 14. Dover,N.J.*..........May, 75.. 4 3 15. Cleveland,O...........Oct. 75. 4 0 16. Washington D. C......Feb.'' 76.: 4 18 17. philadelphia, Pa.......June,: 76.. 5 3 18. Philadelphia Pa........Oct 76.. 5 19 19. New York, N. Y.......Feb: '77.. 5 27 20. Wilkes-Barre. Pa.*.....Mag :77.. 0 3 21. Amenia N. Y..........Oct. 77.. 6 10 22. Philadeiphia Pa........Feb.;' 78. . 6 18 23. Chattanooga' Term.*. . . May' 78. . 7 3 24. Lake George: N. Y....: Oct. 78. . 7 103 25. Baltimore, Md.*.......Feb:' 79.. 7 217 26. ~ittsburgi, Pa.........~a;' 79.. 6 3 27. Montreal, Canada......~ept.;' 79.. 8 121 28. New York, N. Y.*......Feb., '80.. 8 275 29. Lake Superior, Mich....Aug., '80. . 9 1 30. Philadelphia, Pa.*......Feb., '81. 9 275 31. Staunton, Va..........May, '81. .10 1 32. Harrisburg, Pa.........Oct.. '81..10 119 33. Washington, I). C.*....Feb., '82. . 10 226 34. Denver. Colo..........Aug.. '82. . ll 1 35. Boston. Mass.*.........Feb.. '83..11 217 38. Roanoke, Va...........June, '83.. 12 3 37. Troy, N. Y...........Oct.. '83. .12 175 38. Cincinnati. O.*.... Feb, '84..12 4 39. Chicago Ill............May, '84. . 13 1 40. philadelphia, Pa........Sept., '84. . 13 285 41. New York, N. Y.*......Feb., '85. . 13 586 42. Chattanooga, Tenn.....May, '85..14 1 43. Halifax, N. S..........Sept., '85.. 14 307 44. Pittsburgh, Pa.*........Feb.. '86 . . 14 587 45. Bethlehem. Pa.........May, '86 .. 15 Ixiii. 46. St. Louis, Mo..........Oct, 86.. 15 Ixx. 47. Scranton, Pa.*.........Feb.', '87. . 15 lxxvi 48. Utah and Montana.....July '87.. 16 xvii. 49. Duluth, Minn...........July' '87. -16 xxiv. 50. Boston. Mass.*.........Feb.: '88. . 16 xxviii. 51. Birmingham, Ala.......May, '88. .17 xix. 52. Buffalo N. Y..........Oct. '88.. 17 xxiv. 53. New york, N.Y........feb.' ;89 . . 17 xxxi. 54. Colorado..............June' 89 . . 18 xvii. 55. Ottawa, Canada........Oct., 89. . 18 xxiv. 56. Washington, I). C.*. . . Feb. 90. .18 xxx. 57. New York, N. Y........sept:, '93. .19 vii. 58. New York, N. Y.*......Feb. '91. . 19 xxv. 59. Cleveland, O.......... June, :91 . .a xvi. 60. Glen Summit, Pa.......Oct, 111. . 20 lxi. 61. Baltimore, Md.*.......Feb.: '92. .21 xix. 62. Plattsburg, N. Y.......June, '02. . 21 xxxiii. 03. Reading. Pa...........Oct., :92. .21 xliv. 64. Montreal. Canada*.....Feb. 93..21 65. Chicago, Ill............aug.: '93..22 XI. 66. Virginia Reach. Va.*. ...Feb., '04. .24 xwl. 67. Bridgeport Coon.......Oct., '94..24 xxx?. 08. Florida ...'............Mar., '95. .25 xix 69 Atlanta. Ga......... Oct 95. 25 xi 70. Pittsburgh. Pa.*........Feb., '96.. 26 xvii. Trans. No. Place Date Vol. Page 71. Colorado..............Sept. '96. .26 xxix. 72. Chicago, Ill............Feb.. "97.. 27 xvii. 73. Lake Superior..........July '97. .27 xxx. 74. Atlantic City, N. J.*. ..Feb.: :98. .28 xvii. 75. Buffalo N. Y..........Oct. 08. .28 XXXVI. 76. New York,N. Y.*......Feb.: '99. .29 xvii. 77. California.............Sept., ;99. . 29 xlix. 78. Washington, D. C.*.....Feb., 00. .30 xix. 79. Canada...............Aug.. '00. .30 xlv. 80. Richmond. Va.*........Feb.. '01. . 31 xix. 81. Mexico................Nov..'01.. 32 cxviii. 82. Philadelphia Pa. $......May, :02. . 33 xxxv. 83. New Haven, Conn......Oct.. 02.. 33 xlvii. 84. Albany N. Y.*........Feb '03. .34 xxiii. 85. New York, N. Y........Oct.': '03. .34 xi. 86. Atlantic City. N. J.*....Feb., '04. .35 XXIII. 87. Lake Superior..........Sept.'04. .35 dii. 88. Washington. D. C......May' '05. .36 xlii. 89. British Columbia.......July, '05. . 36 90. Bethlehem. Pa.........Feb. '06. .37 xli. 91. London, England.......July: '06. .37 xlviii. 92. New York, N. Y........April, '07. . 38 lii. 93. Toronto, Canada.......July. '07. .38 lix. 94. New York, N. Y........Feb., :08. .39 xli. 95. Chattanooga, Tenn.....Oct.. 08..39 xlviii. 06. New Haven Conn......Feb. '09. .40 xli. 97. Spokane,Wash.........Sept:.'09. .40 xlviii. 98. Pittsburgh, Pa.........Mar.,'10. .41 xxxviii. 99. Canal Zone............Nov.,'10. .41 dv. 100. Wilkes-Barre, Pa.......June. ' 11. . 42 xxxiv. 101. San Francisco, Cal......Oct.. '11..42 xliv. 102. New York. N. Y.*......Feb 12. .43 Ixxvii. 103. Cleveland, Ohio........0ct;' '12.. 44 wii. 104. New York, N. Y.*......Feb.. '13. .45 xv. 105. Butte, Mont...........Aug., '13. .46 ?' 108. New York, N. Y........Oct., 13..47 vii 107. New York. N. Y.*......Feb.. '14..48 xv. 108 Salt Lake City. Otah Aug. :l. 49 5: 109. Pittsburgh, Pa.........Oct., 14. .50 vii. 110. New York, N. Y.*......Feb., '15. .51 xvi. 111. San Francisco, Cal......Sept., '15. .52 xii. 112. New York,N. Y.*......Feb., '16..54 xvi. 1 Arizona...............Sept.,'l6. .55 VII 114. New York, N. Y.*......Feb., '17: .56 vii. 115. St. Louis, Mo..........Oct.. '17..57 vii. 116. NewYork,N. Y.*......Feb.. '18..59 xvii 117. Colorado.....:........Sept.,'18. .60 vii. 118. Milwaukee, Wis........Oct.. '18. .60 x:!: 119. NewYork,N. Y.*......Feb., '19..61 xi. 120. Chicago...............Sept.,' l9.. 62 VII. 121. New York, N. T.*......Feb., '20..63 ix. 122. Lake Superior District. .Aug., '20.. 66 ix. 123. New York, N. Y.*......Feb., '21. .66 xiii. 124. Wilkes-Barre, Pa...... Sept.. : 21.. 66 xix. 125. New York, N. Y.*......Feb., 22. .67 ix. 126. San Francisco. Cal......Sept.,:22. .68 xxix. 127. New York, N.Y.*.....Feb., 23. .69 xxix 128. Canada...............Aug., '23. .69 xxxv! 128.129. New York, N. Y.*......Feb., ;24. .70 xxxi. 130. Birmingham, Ala.......Oct. 24. .71 xxxiii 131. NewYork.N Y.*......Feb.: '25.. 71 xxxviii. 132. 131.Salt Lake City, Utah .. .Sept., '25. .73 xvi 133. New York, N. Y.*......Feb., '26. .73 xxii. 134. Pittsburgh Pa ....... Oct.. '26. .74 xv. 135. New York,' N. Y.*............Feb., '27. .75 x::: 135.136. NewYork,N. Y.*......Feb., '28..76 104 137 NewYork.N. Y.*......Feb., '29. .291 116 138.San FranciscoYork,N.Y. Cal..........Oct. 29..308 406 139. New York, N. Y.*...Feb., '30..30H 1321

Jan 1, 1930

By James J. Dowd

The investigation to evaluate the reserves of coking coal in the United States suitable for the manufacture of metallurgical coke is being made by the Bureau of Mines in three parts: (1) To estimate known measured and indicated recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and (3) to study the carbonizing properties of coals and coal blends not now widely used for metallurgical coke making. This is the eighth of a series of reports giving the results of studies by counties under part (1) of the investigation. (See appendix.) This report covers Jefferson County, Pa., which comprises parts of Marienville, Hallton, Ridgway, Brookville, DuBois, Penfield, Smicksburg, and Punxsutawney quadrangles. (See fig. 1.) A short resume of the chemical and carbonizing properties of the coals is included. Data on the coal beds in the county were obtained from mining companies, land companies, individual landowners, and other sources of authentic information. A base map for each bed in each quadrangle was made to the scale 1 inch equals 1,200 feet. Maps of mines, locations of drill holes, bed and total coal thicknesses, and the outcrop of the bed were plotted on the maps. With all available data plotted, isopach lines were drawn to limit areas of known unmined reserves in beds 0 to 14 inches thick, 14 to 28 inches thick, 28 to 42 inches thick, and over 42 inches thick, These areas of coal reserves also were divided into "measured" and "indicated" categories. All areas in each thickness range and in each category, mined-out areas, areas excluded from the estimate, and areas outside of the outcrop were measured by planimeter on the base maps. Estimates of total reserves 14 inches and more thick and maps for individual beds were prepared from these data.

Jan 1, 1952

By Víctor Guerrero

El objetivo del trabajo es aumentar la ley de cabeza de agua de cobre en 1.0 gr/litro, así como del caudal de agua impregnada en 500.g. P.M en la veta Santa Emilia a través del uso de métodos en la apertura de nuevos puntos de lixiviación. En ese sentido, los métodos utilizados son el de lixiviación en pilas subterráneas de mineral roto en las vetas de cobre, así como la implementación del método de rotura-lixiviación en blocks de vetas mineralizadas de cobre.

Oct 14, 1980