DOCSLIB.ORG

Damage Cases and Environmental Releases from Mines and Mineral Processing Sites

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Damage Cases and Environmental Releases from Mines and Mineral Processing Sites DAMAGE CASES AND ENVIRONMENTAL RELEASES FROM MINES AND MINERAL PROCESSING SITES 1997 U.S. Environmental Protection Agency Office of Solid Waste 401 M Street, SW Washington, DC 20460 Contents Table of Contents INTRODUCTION Discussion and Summary of Environmental Releases and Damages ......................... Page 1 Methodology for Developing Environmental Release Cases ............................... Page 19 ARIZONA ASARCO Silver Bell Mine: "Waste and Process Water Discharges Contaminate Three Washes and Ground Water" ................................................... Page 24 Cyprus Bagdad Mine: "Acidic, Copper-Bearing Solution Seeps to Boulder Creek" ................................ Page 27 Cyprus Twin Buttes Mine: "Tank Leaks Acidic Metal Solution Resulting in Possible Soil and Ground Water Contamination" ...................................... Page 29 Magma Copper Mine: "Broken Pipeline Seam Causes Discharge to Pinal Creek" ................................ Page 31 Magma Copper Mine: "Multiple Discharges of Polluted Effluents Released to Pinto Creek and Its Tributaries" .................................................... Page 33 Magma Copper Mine: "Multiple Overflows Result in Major Fish Kill in Pinto Creek" ............................... Page 36 Magma Copper Mine: "Repeated Release of Tailings to Pinto Creek" .......................................... Page 39 Phelps Dodge Morenci Mine: "Contaminated Storm Water Seeps to Ground Water and Surface Water" ................................................................ Page 43 Phelps Dodge Morenci Inc.: "Contaminated Ground Water Beneath an Unlined Impoundment is Discovered" ................................................. Page 45 Phelps Dodge Morenci Inc.: "Contaminated Ground Water Beneath an Unlined Impoundment is Discovered" ................................................. Page 48 ASARCO Ray Complex: "Airborne Fugitive Dust and Tailings Result from Improper Management and Maintenance" ......................................... Page 51 Contents-i Contents ASARCO Ray Complex: "Emissions from Multiple Sources Result in Opacity Violations and Impacts on Community" ....................................... Page 53 ASARCO Ray Complex: "Mine Discharges Degrade Ground Water and Surface Water" ................................................................ Page 56 ASARCO Ray Complex: "Breaches in Tailings Impoundment Containment Dike Contaminates Eleven Miles of River Sediment" ..................................... Page 61 ASARCO Ray Complex: "Discharges from Mine Threaten Water Quality in a Sensitive Stream" .............................................................. Page 64 ASARCO Ray Complex: "Leachate Solution Overflows Collection Dams to Mineral Creek and Elder Gulch" .................................................... Page 67 Phelps Dodge New Cornelia Branch Facility: "Soil Contamination Results from Improper Disposal of Scrap Metals" .................................................................. Page 73 BHP Copper, Inc. San Manuel Facility: "Heavy Metals Contaminate Soil at Five Locations" ...................................... Page 75 Cyprus Copperstone Gold Corporation: "Disposal of Non-Mine Related Waste Materials in Mine Tailings Piles" .............................................................. Page 77 Cyprus Sierrita Corporation: "Leaks and Seepage Affect Ground Water and Two Nearby Washes" .......................................................... Page 79 FLORIDA Associated Minerals (USA), Inc.: "Turbid Discharge Enters Nearby Creek" .............................................. Page 83 Bartow Phosphate Complex: "Ground Water Contaminated at CF Complex" .......................................... Page 85 Florida Solite Company:"Contaminated Discharge E ..................................... Page 87 Fort Meade Mine: "Phosphate Pipeline Spills to Peace River Tributary" ..................................... Page 89 Highland Mine: "Contaminated Storm Water Enters Tiger Branch Creek" ................................. Page 91 Highland Mine: Contents-ii Contents "Release of Turbid Wastewater Results in Siltation and Fish Kill" ............................................................ Page 93 Hopewell Phosphate Mine: "Mine Water Spill Damages Wetlands and Alafia River" ................................... Page 96 IMC Fertilizer, Inc.: "Gypsum Stack Contaminates Surface Water, Ground Water, and Soil" ............................................................ Page 98 MMM Nichols Phosphate Mine: "Unauthorized Mine Water Discharges Affect Alafia River" ............................... Page 101 Mulberry Phosphates Plant: "Fluoride Contamination at Edge of Authorized Zone of Discharge" ........................ Page 103 New Wales Chemical Complex: "Sinkhole Forms Beneath Phosphogypsum Stack" ...................................... Page 105 Payne Creek Phosphate Mine: "Settling Pond Break Releases Wastewater to Local Streams" ................................................................ Page 109 Potash Corporation of Saskatchewan: "Hazardous Waste Releases Result in Soil Contamination" .............................. Page 112 Potash Corporation of Saskatchewan: "Mining Effluent Degrades Nearby Stream" ............................................ Page 114 Premier Services Corporation: "Ionic Imbalance in Discharge Causes Toxicity" ........................................ Page 116 Riverview Chemical Complex: "Acidic Discharge Kills Fish and Crabs" ............................................... Page 118 MARYLAND Bethlehem Steel Corporation Sparrows Point Facility: "Elevated Chlorine Levels in Discharge to Nearby Water Bodies" .......................... Page 120 Chemetals Inc.: "Toxic Effluents Released from Permitted Outfall to Arundel Cove" ................................................................... Page 123 SCM Chemicals Hawkins Point Plant: "Batch Attack Lagoon Contaminates Groundwater" ..................................... Page 126 SCM Chemicals Hawkins Point Plant: "Chlorine Released to Air During Process Malfunction" .................................. Page 128 Contents-iii Contents SCM Chemicals Hawkins Point Plant: "Multiple Discharges of Highly Acidic Wastewater into the Patapsco River" ........................................................... Page 130 SCM Chemicals Hawkins Point Plant: "Multiple Releases of Titanium Tetrachloride to Air" ..................................... Page 133 SCM Chemicals St. Helena Plant: "Ammonia-Contaminated Effluent Causes Toxicity" ..................................... Page 135 SCM Chemicals St. Helena Plant: "Multiple Discharges of Cadmium-Contaminated Effluent into Colgate Creek" ................ Page 137 SCM Chemicals St. Helena Plant: "Multiple Discharges of Zinc-Contaminated Effluent into Colgate Creek" ............................................................... Page 139 SCM Chemicals St. Helena Plant: "Multiple Turbid Discharges Enter Colgate Creek" ...................................... Page 141 NEVADA USMX, Inc., Alligator Ridge Mine: “Spills of Process Solutions to Soil Surfaces” .......................................... Page 143 The Aurora Partnership Auora Gold Project: “Notice of Violation and Multiple Spills” ............................................... Page 145 Placer Dome U.S. Inc.’s Bald Mountain Mine: “Spills of Process Solution to Soil Surfaces” and “Leak in Primary Line” ..................... Page 148 Battle Mountain Gold Company Battle Mountain Mining Operations .................................................. Page 152 Kinross Mining Company, Candelaria Mine: “Process Releases to Soil Surfaces” ................................................. Page 154 Coeur Rochester, Inc. Mine: “Process Releases to Soil Surfaces” ................................................. Page 156 Cortez Gold Mines: “Process Releases to Surrounding Soils” ............................................. Page 158 Hycroft Resources and Development, Inc., Crofoot Project: “Spills of Process Solutions” ........................................................ Page 161 Independence Mining Company Inc., Jerritt Canyon Gold Project .......................... Page 163 Kennametal Inc., Falcon Nevada: “Spill of Process Solution to Soil Surface” ............................................. Page 166 Santa Fe Pacific Gold Corporation’s Lone Tree Mine: Contents-iv Contents “Process Solution Releases” ....................................................... Page 168 Western States Minerals Corporation, Northumberland Project “Initiated Clean-Up Efforts” ......................................................... Page 170 BHP Copper, Magma Nevada Mining Company: “Process Releases to Surface Waters and Soils” ....................................... Page 173 Round Mountain Gold Corporation, Smoky Valley Common Operation: “Process Releases to Soil Surfaces” ................................................. Page 176 Nevada Gold Mining, Inc, Sleeper Project: “Spills of Process Solution to Soil Surfaces” ........................................... Page 178 Wind Mountain Mining’s Wind Mountain Project: “Spills of Process Solution to Soil Surfaces” ........................................... Page 180 NEW MEXICO Phelps Dodge’s Chino Branch: “Multiple Tailings Spills” ........................................................... Page 182 Cobre Mining Co.’s Continental Mine: “Multiple Tailings Spills and Seeps” .................................................. Page 184 Ortiz Project IV: “Remediation of Groundwater Contamination and Acid Rock
Load more

Recommended publications
  • From Base Metals and Back – Isamills and Their Advantages in African Base Metal Operations
    The Southern African Institute of Mining and Metallurgy Base Metals Conference 2013 H. de Waal, K. Barns, and J. Monama From base metals and back – IsaMills and their advantages in African base metal operations H. de Waal, K. Barns, and J. Monama Xstrata IsaMill™ technology was developed from Netzsch Feinmahltechnik GmbH stirred milling technology in the early 1990s to bring about a step change in grinding efficiency that was required to make Xstrata’s fine-grained lead/zinc orebodies economic to process. From small-scale machines suited to ultrafine grinding, the IsaMill™ has developed into technology that is able to treat much larger tonnages, in coarser applications, while still achieving high energy efficiency, suited for coarser more standard regrind and mainstream grinding applications. The unique design of the IsaMillTM, combining high power intensity and effective internal classification, achieves high energy efficiency and tight product distribution which can be effectively scaled from laboratory scale to full-sized models. The use of fine ceramic media also leads to significant benefits in downstream flotation and leaching operations. These benefits are key drivers for the adoption of the technology into processing a diverse range of minerals worldwide, and offer major opportunities for power reduction and improved metallurgy for the African base metal operations. Keywords: IsaMill, regrind, energy efficiency, inert grinding. Introduction The development of the IsaMillTM, by MIM (now GlencoreXstrata) and Netzsch Feinmahltechnik GmbH, was initiated to enable the development of the fine-grained ore deposits at Mt Isa and McArthur River in Northern Australia. To liberate the valuable minerals and so produce a saleable concentrate this ultrafine-grained ore needed to be ground to a P80 of 7 μm.
    [Show full text]
  • Fossil-Fuel Power Plant at Rush Island, Jefferson County, Missouri
    FINAL ENVIRONMENTAL STATEMENT RUSH ISLAND POWER PLANT - UNITS 1 & 2 UNION ELECTRIC COMPANY BASIC DATA SUBMITTED BY UNION ELECTRIC COMPANY IN CONSULTATION WITH BECHTEL CORPORATION, WESTINGHOUSE ENVIRONMENTAL SYSTEMS, SMITH - SINGER METEOROLOGISTS, AND HARLAN BARTHOLOMEW AND ASSOCIATES PREPARED BY U. S. ARMY ENGINEER DISTRICT, ST. LOUIS, MISSOURI 24 NOVEMBER 1972 o / FINAL ENVIRONMENTAL STATEMENT PROPOSED FOSSIL-FUEL POKER PLANT AT RUSH ISLAND JEFFERSON COUNTY, MISSOURI Prepared By U. S. ARMY ENGINEER DISTRICT, ST. LOUIS, MISSOURI 24 NOVEMBER 1972 PROPOSED FOSSIL-FUEL POWER PLANT RUSH ISLAND, JEFFERSON COUNTY, MISSOURI ( ) Draft (X) Final Environmental Statement Responsible Office; U. S. Army Engineer District, St. Louis, Missouri 1. Nare of Action: (X) Administrative ( ) Legislative 2. Description of Action; Processing of Department of the Army permit under 33 USC 403 for construction of a fossil-fuel power plant and appurtenant structures in and along the Mississippi River. 3a. Environmental Impacts: Conversion of approximately 150 acres o f flood plain land to industrial use, loss of public access route, release of products o f combustion and waste heat to the environment, consumption of approximately 2.5 million tons of coal per year. b. Adverse Environmental E ffects: Increase in concentrations of sulfur dioxide, nitrogen oxides and particulate matter in the atmosphere, loss of some fish on plant Intake screens, loss of fish eggs and larvae carried through cooling system. 4. Alternatives: No project, purchasing power, alternate sites, alternate fuels, other cooling systems. 5. Comments Requested: Region VII, EPA, Kansas City, Mo. Mo. Water Resources Board Dept, of Interior, Washington, D.C. Mo. Clean Water Commission Dept, of Health, Education & Welfare, Mo.
    [Show full text]
  • "Keeping People from Being Killed": Arizona Governor Bruce Babbitt, Public Safety, and the Phelps Dodge Copper Strike, 1983-1984
    Bailey- "Keeping People From Being Killed" 3 "Keeping People From Being Killed": Arizona Governor Bruce Babbitt, Public Safety, and the Phelps Dodge Copper Strike, 1983-1984 James M. Bailey* IMAGES OF CIVIL DISCORD batons to suppress a violent labor-related melee in Clifton. Review of the media's film coverage stuns the 0 n July 1, 1983, more than 2,900 Phelps Dodge senses: a pregnant woman, staggering under the employees representing thirteen labor unions struck effects of tear gas, was handcuffed and detained; angry the copper giant's mining and processing facilities in demonstrators hurled anything they could get their Ago, Bisbee, Douglas, and Morenci, Arizona. Dissatis­ hands on at law-enforcement officials; citizens and fied with the company's latest contract offer, they officers exchanged blows with fists and batons; and a believed a strike would make the public more aware frustrated Bobby Andazola confronted a phalanx of of their concerns. Some workers, however, decided shielded DPS officers by stripping off all of his clothes. that economic security took precedence over union "In the name of Lord God, Lord Jehovah," the naked solidarity and crossed the picket lines for paychecks. Andazola screamed, "would you do this to your own One of those workers was heavy equipment operator brothers and sisters?"3 As fascinating as they are Keith Tallant of Ajo. 1 disturbing, these images represent truly graphic exam­ For this economic security Tallant and his family ples of civil discord. paid a grievous price. Almost a month later, on Still, the question remains: how could this labor July 27, someone fired a .22-caliber bullet at his situation have degenerated during the year to the point home.
    [Show full text]
  • FCX Cu Au Basic Materials Conference Basic
    FCX Cu Freeport- McMoRan Copper Au Gold MM OO RR GG AA NN SS TT AA NN LL EE YY BasicBasic MaterialsMaterials ConferenceConference CrowneCrowne Plaza Plaza TimesTimes SquareSquare NewNew YorkYork CityCity Richard C. Adkerson President & Chief Executive Officer February 22, 2007 FREEPORT-MCMORAN COPPER & GOLD INC. www.fcx.com Cautionary Statement Regarding Forward-Looking Statements ThisThis documentdocument containscontains certaincertain forward-lookingforward-looking statementsstatements ababoutout FCXFCX andand PhelpsPhelps Dodge.Dodge. WhWhenen usedused inin thisthis document,document, thethe wordswords “anticipates”,“anticipates”, “may”,“may”, “can”,“can”, “b“believes”,elieves”, “expects”,“expects”, “projects”,“projects”, “intends”,“intends”, “likely”,“likely”, “will”,“will”, “to“to be”be” and and anyany similarsimilar expressionsexpressions andand anyany otherother statementsstatements thatthat araree notnot historicalhistorical facts,facts, inin eacheach casecase asas theythey relaterelate toto FCXFCX oror PhelpsPhelps Dodge,Dodge, thethe managementmanagement ofof eithereither suchsuch companycompany oror thethe transactiontransaction areare intendintendeded toto identifyidentify thosethose asseassertionsrtions asas forward-lookingforward-looking statements.statements. InIn makingmaking anyany ofof thosethose statements,statements, thethe personperson makingmaking themthem believesbelieves thatthat itsits expectationsexpectations areare basedbased onon reasonablereasonable assumptions.assumptions. However,However, anyany suchsuch
    [Show full text]
  • Mineral Processing
    Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19
    [Show full text]
  • MOLYBDENUM by Michael J
    MOLYBDENUM By Michael J. Magyar Domestic survey data and tables were prepared by Cindy C. Chen, statistical assistant, and the world production table was prepared by Linder Roberts, international data coordinator. Molybdenum is a refractory metallic element used principally until after the nearby Henderson deposit in Empire, CO, about as an alloying agent in cast iron, steel, and superalloys to 100 kilometers east, is exhausted. The Tonopah Mine in Nevada enhance hardenability, strength, toughness, and wear- and was being permanently closed. Molybdenum was produced as corrosion- resistance. To achieve desired metallurgical properties, a byproduct of copper production at the Bagdad and Sierrita molybdenum, primarily in the form of molybdic oxide (MoX) or Mines in Arizona and at the Bingham Canyon Mine in Utah. ferromolybdenum (FeMo), is frequently used in combination with The byproduct molybdenum recovery circuit at the Chino Mine or added to chromium, columbium (niobium), manganese, nickel, in New Mexico remained on care and maintenance. Montana tungsten, or other alloy metals. The versatility of molybdenum in Resources’ Continental Pit in Montana resumed operation enhancing a variety of alloy properties has ensured it a significant in November 2003, with the first shipments of molybdenite role in contemporary industrial technology, which increasingly concentrate expected in early 2004 (Platts Metals Week, 2003d). requires materials that are serviceable under high stress, expanded With byproduct molybdenum recovery at a copper mine, temperature ranges, and highly corrosive environments. Moreover, all mining costs associated with producing the molybdenum molybdenum finds significant use as a refractory metal in numerous concentrate are allocated to the primary metal (copper).
    [Show full text]
  • The Bisbee Deportees' Reception in New Mexico, 1917
    New Mexico Historical Review Volume 67 Number 3 Article 5 7-1-1992 Exiled in the Desert: The Bisbee Deportees' Reception in New Mexico, 1917 Richard Melzer Follow this and additional works at: https://digitalrepository.unm.edu/nmhr Recommended Citation Melzer, Richard. "Exiled in the Desert: The Bisbee Deportees' Reception in New Mexico, 1917." New Mexico Historical Review 67, 3 (1992). https://digitalrepository.unm.edu/nmhr/vol67/iss3/5 This Article is brought to you for free and open access by UNM Digital Repository. It has been accepted for inclusion in New Mexico Historical Review by an authorized editor of UNM Digital Repository. For more information, please contact [email protected]. Exiled in the Desert: The Bisbee Deportees' Reception in' New Mexico, 1917 RICHARD MELZER On July 12, 1917, Sheriff Harry C. Wheeler and 1,197 armed deputies rounded up 1,186 workers in Bisbee, Arizona, and forced them out of town on board an eastbound freight train to New Mexico. Wheeler and his cohorts justified their action by declaring that the deported men were members of a feared labor union known as the Industrial Workers of the World, or IWW. The IWW reportedly had organized local copper miners in a dangerous strike against Bisbee's major employers, in­ cluding the powerful Phelps Dodge Corporation. Actually only about a third of the deportees were members of the IWW, and the miners' sixteen-day strike had all but fizzled out by July 12. But this made no difference to those who had ordered or led the mass deportation. 1 Richard Melzer is ,assistant professor of history in the University of New Mexico­ Valencia campus.
    [Show full text]
  • A History of Tailings1
    A HISTORY OF MINERAL CONCENTRATION: A HISTORY OF TAILINGS1 by Timothy c. Richmond2 Abstract: The extraction of mineral values from the earth for beneficial use has been a human activity- since long before recorded history. Methodologies were little changed until the late 19th century. The nearly simultaneous developments of a method to produce steel of a uniform carbon content and the means to generate electrical power gave man the ability to process huge volumes of ores of ever decreasing purity. The tailings or waste products of mineral processing were traditionally discharged into adjacent streams, lakes, the sea or in piles on dry land. Their confinement apparently began in the early 20th century as a means for possible future mineral recovery, for the recycling of water in arid regions and/or in response to growing concerns for water pollution control. Additional Key Words: Mineral Beneficiation " ... for since Nature usually creates metals in an impure state, mixed with earth, stones, and solidified juices, it is necessary to separate most of these impurities from the ores as far as can be, and therefore I will now describe the methods by which the ores are sorted, broken with hammers, burnt, crushed with stamps, ground into powder, sifted, washed ..•. " Agricola, 1550 Introduction identifying mining wastes. It is frequently used mistakenly The term "tailings" is to identify all mineral wastes often misapplied when including the piles of waste rock located at the mouth of 1Presented at the 1.991. National mine shafts and adi ts, over- American. Society for Surface burden materials removed in Mining and Reclamation Meeting surface mining, wastes from in Durango, co, May 1.4-17, 1.991 concentrating activities and sometimes the wastes from 2Timothy c.
    [Show full text]
  • Nuclear Waste Disposal Crisis
    David A. Lochbaum o PennWell Publishing Company Tulsa, Oklahoma Copyright © 1996 by PennWell Publishing Company 1421 South Sheridan/Po O. Box 1260 Tulsa, Oklahoma 74101 All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transcribed in any form or by any means, electronic or mechanical, including photocopying and recording, without the prior written permission of the publisher. Printed in the United States of America 1 2 3 4 5 00 99 98 97 96 • IV • Chapter 8 • I The NRC first evaluated the spent fuel risk in the Reactor Safety Study (RSS) released in October 1975. 1 The NRC had assumed that a spent fuel accident would only involve one-third of a reactor core's inventory, because the fuel assemblies discharged each refueling outage would be shipped offsite for repro­ cessing shortly thereafter. The NRC considered the spent fuel risk to be small compared to the risk from accidents involving the reactor core. The National Environmental Policy Act of 1969 compelled the NRC to release an environmental impact statement for spent fuel storage in August 1979. The NRC reaffirmed its conviction that the "storage of spent fuel in water pools is a well established technology, and under the static conditions of storage repre­ sents a low environmental impact and low potential risk to the health and safety of the public."2 The NRC recognized that certain actions had eroded the basis for its origi­ nal spent fuel risk analysis: after reprocessing was eliminated, utilities had expanded spent fuel storage capacities at nuclear power plants and disposal had been indefinitely deferred.
    [Show full text]
  • Mineral Beneficiation Contents
    Lecture 10: Mineral Beneficiation Contents: Preamble What constitutes mineral beneficiation Size reduction technology Concentration technologies: Basics Recovery and grade Separation efficiency Illustration on separation efficiency Concentration methods Conclusions References Keywords: mineral beneficiation, Milling, gravity concentration flotation Preamble Mineral beneficiation is the first step in extraction of metal from natural resources. With the depletion of high grade metal ores it is important to increase the metal grade of an ore by physical methods; which are termed mineral beneficiation .The objectives of mineral beneficiation are • To increase the metal grade of ore • To reduce the amount of gangue minerals so that lower volume of slag forms in pyromettallurgical extraction of metals .Slag contains mostly gangue minerals. • To decrease the thermal energy required to separate liquid metal from gangue minerals. • To decrease the aqueous solution requirement in hydrometturgical extraction of metals. In this lecture, mineral beneficiation science and technology are briefly reviewed so that readers can apply materials balance principles. Details about the mineral beneficiation can be studied in the reference given in this lecture. What constitutes mineral beneficiation? Ore is an aggregate of minerals and contains valuable and gangue minerals .The mineral beneficiation involves separations of gangue minerals from ore and is done in the following two stages: 1. Liberation of valuable mineral by size reduction technologies. In most ores the valuable minerals is distributed in the matrix of ore. 2. Concentration technologies to separate the gangue minerals and to achieve increase in the content of the valuable mineral to increase the metal grade. Sizes reduction technologies Size reduction or communication is an important step and may be used 9 To produce particles of required sizes and shapes 9 To liberate valuable mineral so that it can be concentrated.
    [Show full text]
  • Isamill™ Technology Used in Efficient Grinding Circuits
    1 IsaMill™ Technology Used in Efficient Grinding Circuits B.D. Burford1 and L.W. Clark2 High intensity stirred milling is now an industry accepted method to efficiently grind fine and coarse particles. In particular, the IsaMill™, which was invented for, and transformed the fine grinding industry, is now being included in many new comminution circuits in coarser applications. While comminution has always been regarded as important from a processing perspective, the pressure being applied by environmental concerns on all large scale power users, now make highly energy efficient processes more important than ever. The advantages that were developed in fine grinding in the early IsaMill™ installations have been carried over into coarse grinding applications. These advantages include a simple grinding circuit that operates in open circuit with a small footprint, the ability to offer sharp product size classification, as well as the use of inert media in a high energy intensive environment. This paper will examine the use of IsaMill™ technology in fine grinding (P80 below 15 micron), and examine the use of the technology in conventional grinding applications (P80 20 - 150 µm). Recent installations will be examined, including fine and coarse grinding applications, as well as the recent test work that was undertaken using an IsaMill™ in a primary grinding circuit, and the resulting circuit proposal for this site. While comminution has been relatively unchanged for the last century, the need to install energy efficient technology will promote further growth in IsaMill™ installations, and result in one of the biggest challenges to traditional comminution design. 1. Senior Process Engineer, Xstrata Technology, L4, 307 Queen Street, Brisbane 4000, Qld, Australia 2.
    [Show full text]
  • AERATION-BASIN HEAT LOSS by S. N. Talati1 and M. K. Stenstrom,2 Member, ASCE
    AERATION-BASIN HEAT LOSS By S. N. Talati1 and M. K. Stenstrom,2 Member, ASCE ABSTRACT: Recent developments in wastewater aeration systems have focused on aeration efficiency and minimum energy cost. Many other operating characteristics are ignored. The impact of aeration system alternatives on aeration-basin temper­ ature can be substantial, and design engineers should include potential effects in evaluation of alternatives. To predict aeration-basin temperature and its influence on system design, previous research has been surveyed and a spreadsheet-based computer model has been developed. Calculation has been improved significantly in the areas of heat loss from evaporation due to aeration and atmospheric radia­ tion. The model was verified with 17 literature-data sets, and predicts temperature with a root-mean-squared (RMS) error of 1.24° C for these sets. The model can be used to predict aeration basin temperature for plants at different geographical locations with varying meteorological conditions for surface, subsurface, and high- purity aeration systems. The major heat loss is through evaporation from aeration, accounting for as much as 50%. Heat loss from surface aerators can be twice that • of an equivalent subsurface system. Wind speed and ambient humidity are im­ portant parameters in determining aeration-basin temperature. INTRODUCTION The recent emphasis on high-efficiency, low-energy consumption aeration systems has increased the use of fine-bubble, subsurface aeration systems, almost to the exclusion of all other types. Design engineers are choosing this technology over others because of very low energy costs. A factor that is usually not considered is heat loss. Different types of aeration systems can have very different heat losses, which result in different aeration-basin temperatures.
    [Show full text]