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By William E. Greenawalt

IN these days of special legislation for the benefit of various industries one might well consider one branch of human endeavor intimately associated with engineering-that of patents and patent litigation. It is estimated that 85 per cent of all industries in the United States are based directly or indirectly on patents. Most inventors are engineers, and most patent litigation pertains to the engineering industries. It is fitting, therefore, that engineers should be vitally interested in discussing patent affairs, particularly as inventors are not a professional group, and invention is mostly a transitory phase incident to the development of specific industrial problems.

Jan 1, 1937

Mechanism Responsible for Flocculation in Poly (N-Isopropylacrylamide) Temperature Responsive Dewatering - Attractive Interaction Forces Induced by Surface Hydrophobicity

Sep 13, 2010

By AIME AIME

ANOTHER meeting of the Institute has passed into history and it fully sustained the reputation of the Institute as a live organization of the men, and nowadays the women, concerned with the mineral . ? industries and those working therein. The field meetings of, the 1nstitute are cine of its pleasantest and most valuable features. As Dr. Raymond used to say, ((It is good for a mining engineer once in a while to see a mine" and these meetings bring back to the mines those who, through progress into higher executive positions, have come to visit them infrequently, at the same time that they give opportunity for the .younger men to see regions and mines aside from those in which they are then working. This, and the formal and' informal interchange of information resulting,, is of the greatest professional value to all, while the meeting of old and making of new friends causes each meeting to be notable in turn. This year's meeting at Salt Lake City was one of the largest that has been held outside of. New York City; 470 members and guests registered while many more were present at the sessions without attending to this formality. '

Jan 1, 1925

By H. T. Rall

This report summarizes a systematic 20-year study of the organic sulfur compounds in Wasson, Texas, crude oil and, to a lesser extent, of three other crude oils, that has culminated in some 200 individual sulfur-compound identifications. The development and application of special separation and identification techniques generally suitable for the characterization of sulfur compounds in any crude oil are discussed. This report reviews early sulfur literature covering petroleum sulfur compound identifications completed before this study was begun, and cites 58 papers resulting from this work. The sulfur compounds in petroleum, both as to type and quantity, have long been of concern to the petroleum industry, and such compositional data are not only of theoretical interest, but also of practical value.

Jan 1, 1972

By Paul Sarnoff

The economics of precious metals -- depending upon who is involved --could be the economics of hope, of fear, indeed of profit and perhaps survival. For those investors seeking capital gains in a puzzling economy, precious metals involve the economics of hope. Those who are convinced that currency soon won't be worth the paper it's printed on turn to precious metals because of the economics of fear. Gold and silver have been a storehouse of wealth since biblical times. The economics of fear during the past 500 years on the Continent has caused almost every European family to make sure a private stockpile or hoard of gold, silver or coins is at hand in case the paper currency of their country undergoes the kind of disaster that came to the German Mark after World War I. Understandably, for mining companies involved in the production of precious metals, the elements of operations and management are directly concerned with the economics of profit -- and perhaps survival. To the American miner the price of precious metals in the marketplace is a matter of daily concern. After decades of selling silver to the US Government at 64.64 cents an ounce, producing silver mines suddenly became faced with prices breaking $5, $10 and $20 per ounce, and approaching $50 an ounce during the period 1978-1981. What should the miner expect one year in the future? Five years?

Jan 1, 1981

By S. H. Ash

THE BARRIER-PILLAR SYSTEM in the Lackawanna Basin consists of 93 barrier pillars between Archbald and Taylor, Pa. These pillars affect 48 mines, have a total length of 87 miles, and confine 21 underground pools, which contain more than 10 billion gallons of water. From an investigation of size, position, and condition of the barrier pillars, it is apparent that those concerned are uncertain, not only as to the method by which the sizes of the barrier pillars were determined but also as to the stability of those that may be expected to act as dams. Where a barrier pillar must act as a dam, its failure may result in loss of life, the mine, or both; it would be far better had it not existed and thereby given a false sense of security.

Jan 1, 1952

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 C Thompson, D Connelly

The history of mill liners has evolved over time and this paper tracks the changes and development of liner technology. It provides an overview of the primary types of liners, the design and the materials of construction. The design of a mill liner is driven by application, materials of construction, casting technology and handling issues. The choice of solid steel, grid liners, rubber or composites and magnetic liners is based on many factors.The methods used for monitoring wear and predicting eventual change out time are many and varied. The contribution of discrete element modeling (DEM) analysis in predicting wear profile is discussed.Mill trajectory and DEM software programs are used with great effect to predict the effect of lifter height, face angle, high low lifters or mill speed. In the field, trial and operational experience is used or improvements/design concepts at one operation are applied to another. Broken mill lifters, accentuated wear and other problems can be better understood using hardness testing, chemical analysis and photo micrograph analysis of pearlitic or martensitic structure along with fracture face observations. This forms a part of the typical root cause analysis. However given correct and sound liner and lifter, feed and discharge design media selection, and materials of construction, the majority of premature liner or bolting failure is normally attributed to incorrect operational methods such as excessive high ball to feed ratio, incorrect mill speed relating to lifter ball throw, incorrect media selection, "tramp" material entering the mill charge from upstream or recirculating process and understanding the specific mill operation in question.It is hoped that this paper will benefit mill operators who are faced with challenges of improving wear life and at the same time optimizing mill throughput and performance.CITATION:Connelly, D and Thompson, C, 2013. The selection design and application of mill liners for large wet grinding mills, in Proceedings MetPlant 2013 , pp 133-140 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By Michael Amick

Due to the importance of maintaining open airways on a longwall panel, mine management decided to install cribs made of foamed cement. Foamed cement had been used at other company operations on several projects. A recent test at a sister operation had proven the crib installation technique and established that foamed cement cribs could provide better support than wooden cribs. The area to be supported was in a remote location; the limited material needs of foamed cement cribs offered a substantial advantage. In mid February 1993, 75 foamed cement cribs were installed on the tailgate of the active longwall panel. The 75 cribs resisted both horizontal and vertical stresses while successfully supporting the entry.

Jan 1, 1993

By Corby G. Anderson

Since 1985, the Sunshine Mining Company has used a patented nitric-sulfuric acid pressure leaching system for production of silver and copper from a refractory sulfide ore body. To better understand this novel process, a program of lab scale testing was undertaken to quantify the effect of system variables on silver recovery. Some of the factors studied include temperature, agitation, acidity, vessel pressure, particle size, percent solids and oxidizer amount. In turn, this knowledge will be applied in actual plant practice to upgrade reaction time, increase concentrate throughput, raise silver recovery and lower reagent costs. A discussion of plant process changes resulting from lab scale testing is included.

Jan 1, 1991

By Warren H. Weisz

A cement, in the broad sense, is any substance which will cause various materials to adhere to each other. Clay was probably the first material to be used by man as a cement or binding agent. Water occurs in or is mixed with the clay to make it plastic, so that it can be formed in place. The sun and air remove the water from the clay and on drying strength is developed. The clays unless fired are not too resistant to water, therefore, their use is best when restricted to dry areas. Gypsum used as a cementitious material is not the subject of this paper, but its use dates back thousands of years. Gypsum mortars were used by the Egyptians in building such massive masonry structures as the pyramids. The Egyptian mortar consisted of a mixture of sand with burned gypsum (of an impure type of 81.5 per cent calcium sulphate and 9.5 per cent calcium carbonate) for the cementitious material. The burning of this type of cementitious material took place at relatively low temperature. These burning reactions will be covered later when the dehydration of gypsum is discussed. The setting of the partially dehydrated gypsum is considered to be crystallization from a supersaturated solution which deposits crystals of dihydrate (gypsum). In low water-content mixes, the interlocking of the needle-like crystals helps to produce higher strengths. Slaked lime made from limestone burned at higher temperatures (1648 F is generally considered as the calcining temperature, although under certain conditions incipient calcination will take place at 1250 F) is another early-period cementitious material. During slaking with water, a colloidal or amorphous hydrated lime is formed. When it is allowed to dry, it hardens and develops low strengths. On exposure to the carbon dioxide of air in the presence of some moisture, carbon dioxide is adsorbed and part of the calcium hydroxide is converted to calcium carbonate. Structures in which a lime mortar is used continue to grow in strength as this reaction proflesses. Hydrated lime has the disadvantage of not setting under water.

Jan 1, 1960

R. C. BUCKETT (Lake View and Star Limited) : At the outset I should like to add my congratulations to those already extended to Mr..Norwood on his excellent paper, which has given us all an inspiration to strive further to improve our plant recoveries. In some respects this paper has left us so little to discuss without considerable time spent on. further research work. At all points one is met by a baffling array of facts which leave one feeling hesitant to speak.The careful and methodical way in which Mr. Norwood went along step by step until all channels of research presenting themselves were tested to his own satisfaction leaves me with but a few comments to make. Particularly striking to me is the explanation of the residual gold values in calcines by recrystallization of haematite and here is a line to be attacked by future studies. This will be mentioned again later.Particularizing on the paper, the first point that struck me was the method of change of pyrite through to the final haematite. I have never been able to satisfy myself that a sample taken from various positions along a roaster when cooled, as described on p. 397, represented a fair sample of the conditions at that point, but I must confess that I have not found a substitute that did satisfy me.However, the following figures are illuminating... But to fill dry a receptacle of known volume with calcines, as described by Mr. Norwood, gives the following apparentspecific gravities:

Jan 1, 1940

By D. Chetty

Process mineralogy forms an integral part of geometallurgy, with ore body characterisation being but one piece of the puzzle in optimising value derived from ore. This value is not only financial, but importantly speaks to sustainability from environmental and social standpoints. The reactive approach of traditional process mineralogy is increasingly being replaced by predictive methods in the geometallurgical sphere, for which mineralogical information must be timeously acquired on judiciously selected sample sets to understand ore variability and its impact on orebody processing. Such processes are not only metallurgical, but must incorporate mining and waste management protocols. Dwindling resources like water and energy also demand innovative approaches for lowering consumption and/or promoting recycling along the value chain. Addressing such challenges relies on appropriate characterisation of ore behaviour under different process regimes. Coupled with this, emerging characterisation tools are increasingly applied to understand the mineralogy of unconventionallypresented and difficult-to-process ores to meet societal and technology demands. Such tools are often accompanied by the generation of large, computationally intensive datasets, for which data management and storage are key requirements, particularly when deciphering temporal trends in ore and process variability. This paper will elaborate on these themes with examples that highlight the importance of process mineralogy throughout the minerals value chain. Keywords: Process mineralogy, ore characterisation, geometallurgy

Jan 1, 2020

[ENGLISH active earth pressure adapter additive adhesion admixture, addition adsorbed water aggregate air air entrainment air hose allowable bearing value allowable pile bearing load]

Jan 1, 1994

Organization Place Date 1917 American Institute of Architects Philadelphia,.,; Pa. Dec. 26-29 American Society of Mechanical Engineers New York City. Dec. 26-29 American Mining Congress State Chapter Phoenix, Ariz. Dec. 26-29

Jan 11, 1917

By K J. F Logan, P W. Leaman, B A. Tucker

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Nam San copper-gold deposit was discovered in 2011 and is a likely blind extension of the Permian age Phu Kham structurally deformed porphyry/skarn copper-gold deposit.The Nam San mineralisation is hosted within a dominantly sericite altered schist unit located to the north of the current Phu Kham open pit operation and is overthrust by an allochthonous barren cover sequence of limestone, granite and sandstone. Reinterpretation of the Phu Kham geology developed the concept of a possible telescoped porphyry copper-gold system at depth. Initial drilling intersected remobilised copper mineralisation in a basal conglomerate, confirming the concept. A reconnaissance vector array induced polarisation (IP) survey identified a deep chargeability anomaly from which a drilling target was developed from 3D inversion modelling of a detailed follow up dipole-pole-dipole anomaly. Drilling of the chargeability anomaly intersected the blind Nam San copper-gold mineralisation beneath the thrusted cover sequence.The key discovery parameters are the result of an integrated exploration program that included reinterpretation of the local stratigraphy, which developed the concept of a deep blind orebody, IP surveys capable of penetrating through the barren cover and a commitment to a deep directional drilling program to test these concepts and targets. The inferred resource remains open at depth, and further assessment will most likely be through underground development.CITATION:Leaman, P W, Tucker, B A and Logan, K J F, 2015. The discovery of the Nam San copper-gold deposit, Phu Kham, Laos, in Proceedings PACRIM 2015 Congress, pp 515–520 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By L. C. Graton, Joseph Murdoch

I. Introduction......................... 26 1. The Relations of Scale in Geologic Work........ 26 2. General Characteristics of Copper Sulphide Ores..... 29 3. Scope of Present Study................. 31 11. Description of the Important Minerals............ 36 1. Pyrite....................... 36 2. Pyrrhotite....................... 41 3. Chalcopyrite...................... 41 4. Bornite........................ 40 5. Covellite....................... 50 6. Chalcocite....................... 52 7. Enargite...................... 59 8. Tetrahedrite and Tennantite.............. 61 III. Conclusions.......................... 62 I. Introduction. The Relations of Scale in Geologic Work. Many features of human accomplishment rest upon the possibility of representing natural objects on a scale of different magnitude from the actual one. Most drawings, for example, are of very different scale from that of the object depicted, and indeed are useful mainly 011 this account. More important than the question of mere convenience, however, is that of meeting the physical limitations of vision.' Thus, a mural

Jan 1, 1914

By H Möller

The purpose of this paper is to give an overview of the corrosion behaviour of steel in seawater. It is shown that the corrosion products (oxy-hydroxides and calcareous deposits) that are formed during corrosion in seawater have a significant effect on the corrosion behaviour of steel. The chemical composition of the steel determines how protective the oxy-hydroxide corrosion product is. The composition of the seawater influences the nature of the calcareous deposits. This needs to be considered when artificial solutions are used to simulate the corrosion behaviour of steel in seawater. A 3.5% NaCl solution is used frequently for this purpose, but because no calcareous deposits can be formed in this solution, erroneous results in terms of corrosion rates are obtained. The more complex ASTM D1141 artificial solution can be used to include the effects of ions other than Na+ and Cl- in synthetic seawaters. The importance of these other ions on the formation of calcareous deposits is discussed. Keywords: Steel, corrosion, seawater, calcareous deposits, oxy-hydroxides

Jan 1, 2006

Apr. 9, AIME, Chicago Section, Chicago Bar Assn., 29 S. La Salle St., Chicago. Apr. 11-12, Geological Society of America, Cordilleran Section, annual meeting, University of Arizona, Tucson. Apr. 15, AIME, Morenci Subsection, Longfellow Inn, Morenci, Ariz. Apr. 15-17, AIME, South West district meeting, Jefferson Hotel, St. Louis, Mo. Apr. 17, AIME, Utah Section, New House Hotel; Salt Lake City. Apr. 21-22, American Zinc Institute, annual meeting, Hotel Statler, St. Louis. , Apr. 21-23, Chemical, Metallurgical, and Mining Society, and Diamond Drilling Research Laboratory, symposium on diamond drilling, Johannesburg, South Africa. Apr. 22, Assn. of Consulting Chemists & Chemical Engineers, Inc., general symposium, Hotel Belmont Plaza, New York. Apr. 25-26, AIME, New England Regional Conference, Kenmore Hotel, Boston. Apr. 26-May 11, Liege International Fair, Liege, Belgium. May 4-8, Electrochemical Society, Inc., Spring meeting, Benjamin Franklin Hotel, Philadelphia.

Jan 1, 1952

By Sean Gallagher

This report was written in an effort to provide better control measures for low back pain (LBP) and low back disability in the mining industry. There are numerous factors associated with development of LBP, many of which can be effectively controlled while some cannot. Better job design is promoted as the best method of reducing cases of LBP and can also reduce the disability (i.e., lost time from work) associated with LBP when it happens. The report draws attention to what is currently known about LBP, what the causes are thought to be, and discusses recent back injury trends in the mining industry. Research describing unique physical demands in mining, such as the capabilities and limitations of working in awkward postures, is also presented. Methods that can be used to prevent initial LBP episodes are provided, including facilities design and layout for materials and supplies, use of mechanical-assist devices, improved design of lifting tasks, and better seat design. Methods of reducing the disability associated with LBP (including workplace design, proactive return-to-work efforts, communication, and management commitment) are also discussed. The report concludes that control of LBP and disability in mining requires a comprehensive approach to limit the repetitive loading that can occur on the low back due to manual materials-handling tasks and exposure to whole-body vibration (WBV). Specific recommendations include the following: ? Successful LBP prevention efforts require a proactive program that has strong management commitment and incorporates employee involvement. ? More efficient supply handling systems and use of mechanical-assist devices can greatly reduce exposure to hazardous lifting tasks. ? Lifting tasks should be designed to minimize low back stress. Tools to evaluate and redesign lifting tasks are presented. ? Improved seat design can reduce exposure to WBV and improve posture, leading to reduced LBP risk. ? The disability associated with LBP can be reduced. Getting the worker back on the job as quickly as possible is in the interest of everyone involved.

Sep 1, 2008