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The Aluminum Company of America (Alcoa) announced that the second unit at its experimental facility at Palestine, Tex. would begin production -in 1979, increasing the capacity of the facility to 30,000 tons per year. The plant uses an experimental process based on the electrolysis of aluminum chloride and reportedly uses 4 to 5 kilowatt hours per pound of aluminum produced, compared to an industry average of about 7 to 8 kilowatt hours per pound. Alcoa has reportedly signed a letter of intent with the Chinese government under which Alcoa will conduct feasibility studies on two new integrated aluminum projects and modernization of an existing aluminum plant. If the study results are favorable, Alcoa Engineers Inc. and the Import and Export Company of the Chinese Ministry of Metallurgical Industry could negotiate agreements to provide Alcoa technology and services for the projects.

Jan 1, 1979

Throughout October, U.S. producers priced unalloyed 99.5 percent aluminum ingot at 53¢ per pound. Dealers, in last month's domestic market, were quoting unalloyed ingot at a range of 45.5¢-46.3¢ per pound. Costa Rica recently issued a proposal to Japanese aluminum smelters to participate in an integrated aluminum-refining project which would include bauxite development. The project reportedly would include a 600,000-kilowatt hydroelectric power station, a 600,000-metric-ton-per-year alumina plant, and a 300,000-ton-per-year primary aluminum smelter. Two U.S. firms--Aluminum Co. of Amerjca (Alcoa) and Martin Marietta Co.--and several European aluminum smelters are also said to be interested in taking part in this project. Alcoa conducted a feasibility study for the Costa Rican Government in 1970 and estimated the bauxite reserves to contain 150 million metric tons.

Jan 1, 1977

Since the introduction of water cooled test rings the operation of cupelling retort bullion has not alone been sImplified, but has also been the means of concentrating the bullion for the fining test in a much shorter time.The first water cooled test ring which I used was rectangular in shape, inside dimensions 5 ft. 3 in. x 2 ft. IQ in., and made of i in. mild steel plates, with a water space of 9i in. x 3t in. However, it was found that as soon as the filling commenced to wear and the litharge came in contact with the jacket, the plate was gradually affected on the lines of the wash, caused by the blast. After a while the inside steel plate went beyond the factor of safety, and was then substituted on the sides and the front of the test ring by a tin copper plate, which has stood now for the last five years without showing the least signs of wear or leakage.The test remains in use as long as the bottom is regarded as safe, and toward the end of the life of the test the litharge is allowed to work against the copper plate.

Jan 1, 1901

By COLIN A. LAWRENCE, Anthony Del Vescovo

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2017

By Robert B. Hoekzema

This Bureau of Mines report describes the history, characteristics, distribution, and mineral development potential of 21 lode gold deposits in or near the Chugach National Forest (CNF), AK. It includes findings from a 4-yr (1979 to 1982) mineral evaluation of the CNF conducted by the Bureau and the U.S. Geological Survey (USGS). This evaluation, undertaken to provide the U.S. Forest Service with mineral resource data for use in making decisions on land use, included site-specific mapping and sampling of more than 200-lode gold deposits. The data presented here were compiled from the findings of this 4-yr evaluation and from existing literature. Fourteen of the 21 lode gold deposits described in this report contain a combined identified resource of 117,750 short tons (st) averaging 0.55 oz/st Au and 0.2 oz/st Ag. Two mineralized felsic dikes in the Summit Lake-Palmer Creek area contain a combined identified resource of 18 million st grading 0.02 oz/st Au and 0.16 oz/st Ag. Identified resources were not determined for the remaining five deposits because of a lack of information.

Jan 1, 1987

By Gregg Davidson, Lonnie Jacobs, Brett Zernich, Alan Howard, Robert Pintabona

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2014

By J. M. Elder, W. S. Kow

Challenges to new heavy mineral deposit developments are presented. These include land use issues, particle fineness, declining grades, and particle coating, amongst others. Industry responses to these are presented as possible solutions.

Jan 1, 2005

By David L. Borusiewicz, M. Suri Surendra

"Abstract Helical piles have been used as anchors and for supporting lightly loaded structures as a method of underpinning, etc in the past. Recently, helical piles are being used to support new structures because of their simple installation process using relatively light and mobile equipment. This paper presents the results of evaluation and design performed for the temporary support of existing piers during a bridge rehabilitation project.INTRODUCTIONThe helical screw foundation was invented and patented by Alexander Mitchell in England in 1833. He installed screw piles to support lighthouses in the tidal basins of England. Many applications in the earlier years in the USA were in North Carolina and in Florida to support lighthouses (in coastal plain deposits). A lighthouse of similar foundation design is still in use at Key Biscayne, Florida.In the USA, the helical piles were reintroduced as foundation elements for electrical transmission towers. Helical piles were also used for anchoring guys of self supported towers and as tie-backs for excavation support systems. Typically, helical piles are being used for supporting lightly loaded buildings and for underpinning buildings undergoing distress as a means of remediation. The helical piles are not commonly used in the transportation industry.HELICAL PILESHelical pile is a segmented deep foundation system with helical bearing plates welded to a central steel shaft. Load is transferred from the shaft to the soil through these bearing plates. Central steel shafts are available in either a square shaft (Type SS) or a round shaft (Type RS). The Type SS series are available in 38 mm to 57 mm square sizes. The Type RS series are available in 73 mm to 114 mm diameter sizes. Type SS-RS combinations are also available for compression applications in soil conditions where dense/hard soils must be penetrated with softer/loose soils above the bearing strata.The leading segment consists of a shaft with one or more helical plates that are welded to the shaft. The plates vary in diameter from 203 mm to 355.5 mm and have a thickness of 9.5 mm or 13.7 mm. Typically the plate diameter increases from the bottom of the shaft upward. A helical bearing plate or helix is one pitch of a screw thread. All helices, regardless of their diameter, have a standard 76 mm pitch. Being a true helical shape, the helices do not auger into the soil but rather screw into it with minimal soil disturbance. Helical plates are generally spaced a distance of two to three times the diameter of the plate directly below in order for them to function independently as individual bearing elements. A typical detail of helical pile is shown on Figure 1."

Jan 1, 2014

Jan 1, 1885

By George Chung

"The Iron Ore Company of Canada's Carol Lake Project is Located near the western boundary of Labrador, 960 air kilometers northeast of Montreal (Figure 1).The Concentrator operation was started in 1962 with a capacity to produce 7 million tonnes of concentrate per year. The bulk of the concentrate was pelletized at a 6 million tonnes per year pelletizing plant completed in 1963. The remaining concentrate was sold in the international market. The concentrator was first expanded in 1966 to 10 million tonnes per year capacity with the pellet plant also expanded in 1967 to match the increase in concentrate production. In 1973, the concentrator was further expanded to gear with the increase in concentrate sales. In 1977, more than 40 million tonnes of crude ore was processed to produce in excess of 17.4 million tonnes of concentrate and 10.4 million tonnes of pellets."

Jan 1, 1980

By A. L. Podia

The purpose of this research was to develop a system capable of detecting changes in the structure of rocks, leading to failure of mine roofs, and/or excavations. A prototype system was developed, field tested and delivered to the United States Bureau of Mines for further evaluation and research. This system is based on the analysis of acoustic signals generated on the surface of the roof by an impact device and which are reflected or backscattered by flaws and discontinuities in the rock. The specially designed impact source is capable of generating high frequency acoustic signals with excellent repeatability. The system can also be used in conjunction with conventional acoustic pulse transducers. The received signal is digitized and the data transferred to a minicomputer for processing and display. This capability allows the immediate determination of wave velocity and/or distance to a reflecting interface. Various data processing techniques such as averaging, differentiating, and comparing of different signals can be selected by entering the appropriate commands on the keyboard. Being a programmable system it is possible to implement more advanced signal processing techniques. All results as well as the signal are displayed on a CRT. Furthermore, a permanent record of the data can be generated on paper tape, which can be reentered and processed at a later date. A communications interface allows transmission of the sampled signal to a large scale re-mote computer. The system was tested extensively in the laboratory, and field tested at the York Canyon Coal Mine. These tests proved the feasibility of operation in the mining environment. Results indicate that further investigation and development will have to be undertaken to fully develop the potential of this system in satisfying the goals of this research.

Jan 1, 1973

A major domestic aluminum producer raised its price for primary aluminum metal from 44 cents per pound to 48 cents per pound, effective August 5, 1976. Other major producers have increased their list prices by equivalent amounts COAL: The strike which began July 19 in southern West Virginia enlarged by early August to involve approximately 80,000 miners in nine States. As of August 4, the aggregated loss of production is estimated to be 5.8 million tons. Reportedly, at this time, the railroads which serve the struck areas are feeling the largest impact with coke plants and electric utilities relying on stocks which are generally high.

Jan 1, 1976

By G. S. Beaumont

This report presents a programme of work to demonstrate the use of a surface-based centralised computer control system for the remote monitoring and control of underground conveyors in a US coal mine. The system selected for demonstration was the 'Dynalink' Micro MINOS system which is manufactured by Hawker Siddeley Dynamics Engineering Limited. The site selected was Barnes S Tucker Lancashire No. 20 Mine located near Carrolltown, Cambria County, Pennsylvania. The system concept, operating and application software was designed and developed by the. British National Coal Board. The report describes the selection of the site, specification of the system requirements, commissioning, operation and evaluation of the system under typical US mine operating conditions. Experience with the system, based primarily on the system reliability and performance of conveyor control, was favourable. Mine management personnel felt that the system had successfully achieved its objectives and were keen to expand monitoring and control to other activities.

Jan 1, 1986

By J. N. Van der Merwe, D. P. Roberts

The two components of pillar design formula being used in South Africa are pillar strength and pillar load. While considerable effort has been directed to the determination of pillar strength, the other half of the safety factor equation, the load, has not received the same amount of attention. The load acting on pillars has always been calculated using the Tributary Area Theory (TAT). This paper summarises the recent studies on coal pillar loading using various numerical models. It concludes that although there are meaningful differences under certain circumstances, there is still a compelling argument to use the TAT in coal pillar design. Les deux parties composantes de la formule de conception de pilier généralement utilisée en Afrique du Sud sont la résistance de pilier et la charge de pilier. Tandis que des efforts considérables on été dirigés vers la détermination de la résistance de pilier, l’autre moitié du facteur de sécurité n’a pas reçu la même attention. La charge agissant sur les piliers a toujours été calculée avec la Théorie d’Aire Tributaire (TAT). L’étude présente résume les études récentes sur la charge de pilier de charbon utilisant des modèles numériques variés. La conclusion est que bien qu’il y ait des différences significatives selon les circonstances, il y a toujours un argument puissant pour utiliser le TAT dans la conception de pilier de charbon. Die in Südafrika für die Auslegung von Pfeilern verwendeten zwei Formelkomponenten sind Pfeilerstärke und Pfeilerbelastung. Während beträchtlicher Aufwand zur Bestimmung der Pfeilerstärke gemacht wurde, wurde der anderen Hälfte der Sicherheitsfaktorsgleichung nicht die gleiche Aufmerksamkeit gewidmet. Die auf die Pfeiler wirkende Last wurde immer unter Verwendung der Tributary Area Theory (TAT) berechnet. Diese Arbeit fast neuere Studien betreffend der Belastung von Kohlepfeilern unter Verwendung verschiedener numerischer Modelle zusammen. Die Schlussfolderung ist, daß obwohl unter bestimmten Vorraussetzungen bedeutende Unterschiede existieren, nach wie vor ein bezwingendes Argument besteht TAT in der Kohlepfeilerauslegung zu verwenden.

Jan 1, 2003

By Paul M. Tyler

MUCH has been said in print, and much more that was unprintable, about burdensome controls, taxation, and multiplying restrictive, regulatory, or taxing activities of the Federal Government, but not so much has been said about ways and means whereby the Government can and does render economic assistance. Economics has been defined as the study of men earning a living, and economic assistance to industry as well as to individuals properly should take the form of helping enterprisers to help themselves rather than charity. Proposals to have the Government play Santa Claus must be examined carefully if -only to avoid undue favoritism to politically important persons and downright venality by potentially crooked public officials. Thomas Jefferson is credited with the remark that the best government is the one which governs least. Paternalism is abhorrent to most Americans.

Jan 1, 1947

By Arthur Matzick

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Jan 1, 1966

By Allen G. Gray

It's not news to you that the United States is highly vulnerable to potential problems in supply of critical and strategic metals, and that these metals - chromium, for example - are employed in important bearing alloys. It's also not news to you that there is a significant challenge to improve durability and life of bearing systems which contribute to conservation as well as productivity. The objectives of this workshop are to identify available technologies and opportunities for new technologies in conservation, substitution, and displacement of critical and strategic metals in bearing systems. These considerations are among the most viable options for reducing vulnerability to a cutoff of chromium and other critical metals and action should be taken to identify and develop those technologies now rather than after a crisis is upon us.

Jan 1, 1984

By Walter Renton, Ingalls

SEVERAL years ago I became interested in computing the historic lead production of the United States, and the mines, or mining districts whence derived. This led me subsequently to an examination of the recent records- of some of the American zinc-mining districts and of the great lead and zinc-mining districts in foreign countries. My present article thus will be to a large extent an addendum to my book, "World Survey of the Zinc Industry," which was published by the Mining and Metallurgical Society of America in 1931, and to which I shall refer hereinafter as Ingalls, op. cit. Throughout this article all expressions of tons mean the ton of 2000 lb. Where original data have been given in metric tons I have converted in many instances simply by multiplying by 1.1, and long tons by 1.12. I have not been fussy about digits and have rounded off many figures. These may explain differences between data herein and other data.

Jan 1, 1946

By C. Travis Anderson

"Nickel is an essential metal in stainless steel, armor plate, and nickel steels and also in nonferrous alleys, such as monel metal and cupre-nickel, which are used in marine service. Nickel is one of the metals that must be greatly restricted in civilian use to provide the amounts needed for our War program. Consequently, it is desirable to investigate every possible substitute.The 5-cent coin no z in use contains 2.3 percent nickel. At the end of 1941, about 450 tons of nickel was being consumed annually to produce these coins. If the nickel used for that purpose in 9141 had been diverted to military use, 15,000 tons of armor plate could have been produced. As nickel is vitally needed for military as well as essential civilian products, it would seem desirable to substitute some other alloy for the 25 percent nickel alloy now being used. The Bureau of Mines has been asked to suggest possible substitutes.The substitute should have physical properties similar to the alloy now being used. It should have a metallic appearance and ring and a reasonably white color, so to be distinguishable from the present 1-cent coin. It should also be reasonably resistant to corrosion."

Aug 1, 1942

By Theron A. Klinefelter, Sidney Speil, Sidney Gottlied

"INTRODUCTION The investigation of domestic talcs by the United States Department of the Interior Bureau of Mines, was initiated in December 1941 at the request Gen. Charles Hines of the United States Army. The urgency for such study was expressed by General Hines as follows:The radio-manufacturing industry has recently been expanded by the Army to provide sufficient, capacity for defense needs, and considerable concern has been expressed by the supply Arms and Services over maintaining continued availability of supplies of the necessary raw material. These ceramic products are used by the Signal Cores in all Army radio equipment, and to a greater degree in the new special ultra-high-frequency equipment. The Air Corps has recently become a user large amounts of radio-grade ceramics for aircraft spark-plug covers required for high-altitude operations. In addition, the use of this material is essential to the proper functioning of the radio-navigation aids of the Civil Aeronautics Board.Progress in the Bureau of Mines studies on talc was made available to representatives of the Army and Navy through frequent interim reports. Through the efforts of the several war agencies concerned with raw-materials supply and the domestic talc producers, the condition of scarcity that developed in 1942 passed to one of ease in 1943, and has so continued to date. Tentative estimate of reserves delineated indicates a supply of high-grade steatite sufficient to meet military war requirements for at least 4 or 5 years."

Apr 1, 1945