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By Ernest Wiltsee

The Half-Moon mine, situated three miles west of the town of Pioche, exhibits geological features which are peculiar and interesting. The general formation in the vicinity of Pioche consists of a quartzite, usually covered with an overlying limestone containing strata of shale. In the camp itself, where the original mines are situated, the quartzite has been denuded, and the principal veins outcrop in this formation; to the west, the quartzite is again covered with limestone, containing thin strata of shale.

Jan 1, 1893

By William H. Meadows

This information describes the ventilating and methane gas testing procedures utilized during the raising of a mine shaft using a Robbins 81-R drill. An overview of the raise boring process is presented to illustrate the ventilating and gas testing procedures. A mine shaft project, 4.88 m (16 ft) in diameter and approximately 457.2 m (1500 ft) in length, will be the focal point of the presentation, with reference to similar projects for additional comments on variations in procedure.

Jan 1, 1980

The introduction ofa submerged entry tundish nozzle incorporating a cylindrical internal space for argon distribution to its inner bore slab is described. In co-operation with the refractory supplier, four major phases of nozzle development have been undertaken. Problems as well as successes are outlined.Significant reduction in alumina clogging ofnozzles has been achieved along with a decrease in nozzle consumption, using resin bonded alumina graphite with up to 4 different materials "zoned" to give resistance to thermal shock, gas leakage, and erosion.

Jan 1, 1985

By Ken Tunnel

In the spring of 2005, the Lake Superior Chapter of the ISEE invited me to speak about raw materials used for blasting, anhydrous ammonia and the effect of this important feedstock on the cost of ammonium nitrate.The invitation was extended because our company is involved in trading ammonia and the production of ammonium nitrate. In a response to a request to update that presentation, it struck me how events such as hurricanes Katrina and Rita can change the landscape of our businesses.

Jan 1, 2007

By William E. Ford, Edward Salisbury Dana

Normal phosphoric acid is H3P04, and consequently normal phosphates have the formulas R3PO4, R3(P04)2 and RPO4, and similarly for the arsenates, etc. Only a comparatively small number of species conform to this simple formula. Most species contain more than one metallic element, and in the prominent Apatite Group the radical (CaF), (CaCI) or (PbCI) enters; in in the Wagnerite Group we have similarly (RF) or (ROH).

Jan 1, 1922

By Rafael Masulck Santos

Este trabalho tem o intuito de correlacionar as principais variáveis dos processos de Recozimento em Caixa e Laminação de Encruamento com as características magnéticas de aços Laminados a frio para fins elétricos de grãos não orientados destinados às aplicações “totalmente processadas” e “semi processados”. Foram utilizadas diferentes temperaturas e tempos de encharque, e posteriormente distintos passes de redução no processo de Encruamento. As microestruturas resultantes das variações dos parâmetros de processo foram analisadas e correlacionadas com as características magnéticas obtidas por ensaio Epstein.

Aug 17, 2017

By Claudia Gasparrini

Silver occurs in nature in major, minor and variable amounts in a very large variety of minerals and in several mineral species in the same ore. Because these minerals may respond differently to the same flotation or leaching agents, detailed studies to establish the correct silver mineralogy become essential for optimum recoveries in those situations where the silver is treated as a primary product. On the other hand, fine grain sizes, which often affect gold recoveries, are not generally as critical in silver metallurgy, due to the lower market price which allows for more of the element to remain In the tailings before incurring in economical losses.

Jan 1, 1984

Thirty years ago a party of American Engineers, with members of their families, belonging to the four national engineering societies, sailed for Europe and visited England and the Paris Exposition of 1889 and received many courtesies, official, professional, and individual. Plans: have been made for a reunion dinner to be held in New York City, about May 26, at which it is hoped that all survivors, ladies as well as men, of that trip may meet again. It is, therefore, urgently requested that anyone who was of that party communicate immediately with the Secretary of the Committee, Jesse M. Smith, Engineers' Club, 32 West 40th St., New York, N. Y. Announcement of the precise date and place, and full details, will he sent to every individual who can he reached.

Jan 5, 1919

By R. J. Sweigard

Many states are considering the need to establish or modify policy relating to the disposal of coal ash. One of the primary concerns is the impact of leachate from the ash disposal sites upon groundwater and nearby bodies of surface water. A detailed site investigation was conducted at a coal ash disposal facility associated with a power generation station. The disposal site is situated alongside a major river. Monitoring wells were installed and soil samples were taken for characterization. Groundwater models were used to simulate migration of leachate from the disposal site toward the river. Such models have the potential to be used to verify regulatory compliance. This paper addresses the validation and adaptability of these models to this case and their usefulness as possible tools to be used in future environmental audits.

Jan 1, 1993

Produce an annotated bibliography to serve as a comprehensive source of published information available on the use of soil amendments in coal mine reclamation and the characterization of coal mine soils. The Problem There is a substantial amount of information available tin coal mine reclamation and revegetation, particularly on the use of soil amendments to ameliorate site conditions and aid vegetation establishment, growth development, and productivity. Additionally, site characterizations based on chemical, physical, and mineralogical properties have been thoroughly researched. This information, however, is widely disseminated throughout various professional and scientific journals, State and Federal documents, proceedings of conferences, theses, and other technical writings. A critical need exists for a comprehensive and up-to-date summary of published information concerning the uses, methodologies, and types of soil amendments that arc necessary for reclamation success.

Jan 1, 1991

By Goldstone A

The paper introduces a newly developed multi-function test rig for fracture grouting. This test rig has many functions and its performance is consistent. It can control and adjust accurately the opening degree of fissures and static pres- sure; it can measure automatically the quantity of grout injected; it can measure precisely pressure drop of grout in fissures; it can test the results of injection, including effective dispersed distance, anti-filtration capacity of consolidated body, mechanical strength, etc. It can inject a single or two grouts into one or several fissures at a pressure of 16 MPa. Therefore, it is an ideal test rig for fracture injection. The paper depicts all the components of the test rig, its performance and application of the results obtained from fracture grouting tests. Examples are briefly described.

Jan 1, 1988

By Ashis Bhattacherjee, Subrata Chatterjee, Michael T. Dewey, Christopher J. Bise

In order to continue the advancements made during the past two decades in the reduction of the severity of accidents and injuries in underground coal mining, closer attention will have to be paid to the increasing number of accidents resulting in disabling injuries and lost time. With the increased emphasis on safety training reflected in the Federal Mine Safety and Health Amendments Act of 1977 (Public Law 96-1641, and on MSHA's current focus on the application of Job Safety Analysis, it appears that the acquisition, evaluation, and application of accident and incident data will take on an even greater importance. To manage this large amount of information will require a significant commitment of time and attention on the part of mine training departments. A USBM-sponsored research project is currently being completed at Penn State which focuser on the development of a model training program for mining. The program is based on five distinct steps which represent the coupling of a needs assessment with the program implementation. The five steps are: 1) database analysis, 2) workplace observations, 3) identification of trainable problem areas, 4) a library of training resources, and 6) the implementation of the program. In each of these areas, the microcomputer has proven to be a valuable tool for collecting, analyzing, and presenting accident and incident information. This paper will detail the manner in which microcomputers have been fully integrated into the model training program. Examples of applications at existing mines will also be discussed.

Jan 1, 1992

By Muller GP, van Deventer JSJ

A mineralogical analysis has shown that in the Hartebeesfontein ore studied, uranium is associated mainly with uraninite, sulphides such as pyrite and to a lesser degree carbonaceous material such as thucolite. Little could be learned from the literature regarding the mechanism of flotation of these uranium-bearing minerals. A wide variety of reagents were used so that conditions enhancing the flotation of either the sulphides, carbonaceous material, oxides like uraninite, or combinations thereof, were created. As could be expected, the xanthate based floats gave-better selective recovery of sulphides than oleic acid. A substantial fraction of the uranium is associated with pyrite, so that addition of oleic acid to a xanthate float did not enhance the recovery or grade of uranium. After a pre-leach with sulphuric acid in which the pH and Eh were controlled so as to destroy the uraninite, higher uranium recoveries were obtained for the combined float (xanthate, DTP and oleic) and the DTP float. This was most evident when iron was added before flotation. Roasting, which destroyed the sulphides and thucolite, caused a significant decrease in uranium recoveries. The uranium liberated in this way was obviously not flotable in the same way as the uranium liberated from uraninite. A small amount of iron (2 kg/t) added before milling resulted in slightly higher grades and recoveries of sulphur for xanthate based floats. Higher iron additions had a detrimental effect on sulphur recoveries. Even in the case of oleic acid the addition of small amounts of iron had a positive effect on the recovery of sulphur and uranium.

Jan 1, 1993

ARTHUR BRICE deSAULLES In the death of, Major A. B. deSaulles at South Bethlehem, Pa., on Dec. 24, 1917, the Institute lost a valued and esteemed member, one of the last few of those who, in May, 1871, at Wilkes-Barre, attended the first meeting of the Institute, in response to a call that had been issued by R. P. Rothwell, Eckley B. Coxe, and Martin Coryell. Major deSaulles was born Jan. 8, 1840, at New Orleans, and was the son of Louis and Armide Longer deSaulles, each of French descent. As a boy he was privately tutored in the South, and then schooled in New England to enter the Rensselaer Polytechnic Institute, where he was graduated with honors in the class of '59. Following his graduation he studied in France and Germany for two years, returning to New Orleans in 1861 to enter the Confederate Army, in which he served with distinction- as an engineer throughout the Civil War, rising to the rank of Major and the command of his Corps. After the close of the war he pursued his studies abroad for another year, returning to New York in April, 1866, when be became engineer for the New York & Schuylkill Coal Company, and remained at its plant near Wilkes-Barre until October, 1871, when it was sold to the Philadelphia & Reading Coal and Iron Company.. He then returned to New York where for several years he was engaged in the practice of his profession. In 1869, he married Catharine M. Heckscher, daughter of Charles Heckscher of New York City. Mrs. deSaulles survives him. In 1876, Major deSaulles became superintendent of the Dunbar Furnace Company in Fayette County, Pa., with which company he remained until 1883. As a feature of the Pittsburgh meeting in May, 1879, Major and Mrs. deSaulles entertained the members of the Insti-

Jan 4, 1918

By Victor Freire de Oliveira

A exaustão das reservas mundiais de minérios de ferro de qualidade, bem como o progressivo avanço das legislações ambientais, são tendências que têm motivado pesquisas acerca do uso de resíduos ricos em ferro e carbono para a fabricação de sínter metalúrgico para uso em alto-forno. Para tal, é necessário que se verifique o comportamento desses materiais nas condições termodinâmicas e cinéticas do processo de sinterização, bem como o seu efeito sobre a qualidade do sínter e sobre os parâmetros de processo da sinterização. Com esse objetivo, em uma primeira etapa do presente projeto de pesquisa, misturas representativas da prática operacional das usinas brasileiras, bem como misturas visando à maximização da reciclagem de resíduos foram testadas em laboratório em condições próximas às da sinterização. Os resultados de análises químicas e mineralógicas obtidos experimentalmente foram comparados com predições termodinâmicas de um modelo de equilíbrio multicomponente, havendo concordância satisfatória.

Oct 30, 2017

By Felipe da Silva Siqueira, Weslley Luiz da Silva Assis, Gláucio Soares da Fonseca, André Luiz Moraes Alves, Guilherme Dias da Fonseca, Paulo Rangel Rios

Com o contínuo advento dos materiais aumenta-se as chances de uma dada transformação envolver duas ou mais fases produto. Quando essa transformação de uma fase matriz em duas ou mais fases produto ocorre, ela pode ser simultânea, quando as fases produto iniciam-se no mesmo instante, ou sequencial, quando elas iniciam-se em tempos diferentes. É sabido, pela teoria clássica da nucleação, que a nucleação heterogênea tem vantagens sobre a nucleação homogênea, e que vários sítios podem se tornar preferenciais por favorecerem a nucleação heterogênea. Dois sítios preferenciais bastante presentes são a interface de precipitados e os contornos de grão. Neste contexto, um modelamento analítico e computacional, via cone causal, foi empregado para investigar transformações simultâneas e sequenciais que possuem sítios preferenciais para a nucleação. Considerou-se que uma fase matriz policristalina que possui precipitados esféricos transforma-se em duas fases produto, 1 e 2, onde a fase produto 1 nucleou na interface matriz/partículas e a fase produto 2 nos contornos de grão. Os resultados de simulação tiveram ótima concordância com o modelamento analítico e observou-se que cada sítio preferencial teve um efeito muito distinto nas microestruturas simuladas.

Oct 4, 2019

Jan 1, 2004

By A. Smith

The practice of leaving barrier pillars between adjacent longwall panels at The Durban Navigation Collieries (Pty) Ltd (Dumacol) has resulted in a considerable loss of coal reserves. Dumacol has now modified the layout of its longwall panels to allow the concurrent mining of barri9f pillars and the extraction of the longwalls. The Implementation of the new panel layout has increased the percentage extraction of reserves and will result in an extension in the life of the mine. The method of extracting barrier pillars between adjacent longwall panels is described in this paper.

Jan 1, 1985

By David B. Ashley

Risks in underground construction are often viewed as technical in nature; "running ground, " "squeezing ground" and "chimneys" are terms that appear in construction managers' nightmares, and occasionally in their underground projects. Financial consequences of these and other project risks are reviewed. Special attention is paid to sources of cost overruns. From this study a structure evolves for setting priorities for risk management actions; these actions can also be tested for impact and potential effectiveness. Finally, case study reviews of six underground projects indicate the "state of the practice" for financial risk management.

Jan 1, 1983

By P. R. A. Andrews

Magnesite, brucite and dolomite occur widely throughout Canada, but deposits of economic significance are found only in Quebec, Ontario and British Columbia. Magnesite occurs in all three provinces, brucite in Quebec and Ontario and dolomite in Ontario. Beneficiation of refractory magnesium minerals has been the subject of many investigations at CANMET and the former Mines Branch. Twenty-three magnesite, four brucite and nine dolomite evaluation studies were conducted between 1920 and 1974. A review of some of the more important studies is presented. The information includes mineralogy, beneficiation methods and flotation data.

Jan 1, 1995