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Author Mitchell, P.; Wheaton, A.
Title From environmental burden to natural resource; new reagents for cost-effective treatment of, and metal recovery from, acid rock drainage Type Book Chapter
Year 1999 Publication Sudbury '99; Mining and the environment II; Conference proceedings Abbreviated Journal
Volume Issue (up) Pages
Keywords acid mine drainage Bunker Hill Mine cost decontamination Idaho metal ores mines mitigation natural resources pollution reagents recovery Shoshone County Idaho sludge United States zinc ores 22 Environmental geology 27A Economic geology, geology of ore deposits
Abstract Acid rock drainage remains the greatest environmental issue faced by the mining sector and as the new millennium approaches, low capital/operating cost treatments remain elusive. Therefore as part of an ongoing process to develop a leading edge, innovative and cost-effective approach, pilot trials were conducted by KEECO in collaboration with the New Bunker Hill Mining Company on a substantial and problematic metal-contaminated acid flow, emanating from underground workings at the Bunker Hill Mine, Idaho. The aims of the work were fourfold. First to assess the capacity of KEECO's unique Silica Micro Encapsulation (SME) reagents and associated dosing systems to cost-effectively decontaminate the acid flow to stringent standards set by the U.S. Environmental Protection Agency (USEPA), where alternative and standard technologies had failed. Second, to demonstrate that treatment using a compact system suitable for underground installation. Third, to demonstrate that the treatment sludge had enhanced chemical stability in absolute terms and relative to standard approaches. Fourth, to examine the potential for resource recovery via sequential precipitation. Although the focus to date has been the development of a cost-effective treatment technology, the latter aim was considered essential in light of the growing pressure on all industrial sectors to develop tools for environmentally sustainable economic growth and the growing demands of stakeholders for improved resource usage and recycling. Two phases of work were undertaken: a laboratory-based scoping exercise followed by installation within the mine workings of a compact reagent delivery/shear mixing unit capable of treating the full flow of 31 L s (super -1) . At a dose rate of 2.0 g L (super -1) (equivalent to a final treated water pH range of 7-9), the SME reagent KB-1 reduced metal concentrations to levels approaching the U.S. Drinking Water Standards, which no other treatment piloted at the site had achieved. Based on the USEPA's Toxicity Characteristic Leaching Procedure, the sludge arising from the treatment was classified as non-hazardous. Operating costs compared favourably with those of lime use, while estimated capital costs were considerably lower due to the compact nature of the reagent delivery system and the rapid settling characteristics of the treatment sediment. Resource recovery was attempted using a two-stage selective precipitation approach. The first stage involved pH adjustment to 5.5 (by addition of 1.5 g L (super -1) of KB-1) to produce a sludge enriched in aluminium, iron and manganese, with lesser amounts of arsenic, nickel, lead and zinc. Further KB-1 addition to a total of 2.1 g L (super -1) generated sludge enriched in zinc (33% by dry weight), demonstrating that resource recovery is theoretically feasible. Further work on downstream processing is required, although it is considered that the most likely route for zinc metal recovery will be high temperature/pressure due to the chemically inert nature of the zinc-rich sediment.
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Corporate Author Thesis
Publisher Place of Publication Editor Goldsack, D.E.; Belzile, N.; Yearwood, P.; Hall, G.J.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0886670470 Medium
Area Expedition Conference
Notes From environmental burden to natural resource; new reagents for cost-effective treatment of, and metal recovery from, acid rock drainage; GeoRef; English; 2000-048642; Sudbury '99; Mining and the environment II, Sudbury, ON, Canada, Sept. 13-17, 1999 References: 3; illus. incl. 5 tables Approved no
Call Number CBU @ c.wolke @ 16593 Serial 296
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Author Kuyucak, N.; Lindvall, M.; Rufo Serrano, J.A.; Oliva, A.F.
Title Type Book Whole
Year 1999 Publication Abbreviated Journal
Volume Issue (up) Pages 473-479
Keywords HDS lime sludge mine water treatment
Abstract Lime neutralization is a frequently used method in the mining industry for the treatment of acid waters. These waters contain metal ions such as zinc, manganese, copper, cadmium, lead, etc. The conventional, straight lime neutralization technology generates a Low Density Sludge (LDS) having only 1-2% solids content. This creates sludge disposal difficulties, and results in the loss of potentially large quantities of recovered water, which in turn increases the demand for fresh water requirements for mining/milling activities. The High Density Sludge (HDS) process, on the other hand, is the state-of-the-art technology in North America. It generates a dense sludge with less volume and better particulate properties. Furthermore, the typical gelatinous nature of the sludge changes to a granulated, sand-like texture. Boliden Apirsa, S.L. investigated the feasibility of an HDS process to increase the treatment capacity of their existing plant, and resolve the issues associated with the LDS process for their Los Frailes project. The project required, given that the production of ore was going to be doubled, a significant increase in water was needed without altering the water reservoir sitting north of the concentrator. In addition, the final effluent quality was a priority issue. First, a pilot-scale study was undertaken in 1996, and parameters critical to the design and performance of the process were determined. The results showed that the HDS process could significantly improve the sludge characteristics by increasing the solids fraction from 1.5 to 12.0%, thereby decreasing the sludge volume to be disposed to the tailings ponds by a factor of 10. A full-scale, HDS lime neutralization treatment plant for an average flow rate of 1500 m3/hr was designed and was commissioned in early 1998 in collaboration with Colder Associates, Ottawa, Canada. So far, the full-scale treatment plant has been generating a sludge with more than 30% solids content, exceeding its target value of 12% solids. It produces excellent effluent quality, and scaling in the handling equipment is virtually eliminated. The sludge has dense, easily settable granular particles rather than fluffy flocs, yet has low viscosity that facilitates its unassisted gravity flow. The process has resulted in an increase in the treated water volume. The rate of lime consumption per unit volume of water treated also decreased. The process principles and the steps taken in process development will be discussed and the results obtained to date will be summarized in this communication.
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Publisher International Mine Water Association Place of Publication Ii Editor Fernández Rubio, R.
Language Summary Language Original Title
Series Editor Series Title Mine, Water & Environment Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Implementation of a High Density Sludge “HDS” Treatment Process at the Boliden Apirsa Mine Site; 1; VORHANDEN | AMD ISI | Wolkersdorfer; FG als Datei vorhanden 4 Abb., 4 Tab. Approved no
Call Number CBU @ c.wolke @ 9751 Serial 322
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Author Aube, B.C.; Zinck, J.M.
Title Comparison of AMD treatment processes and their impact on sludge characteristics Type Journal Article
Year 1999 Publication Abbreviated Journal
Volume Issue (up) Pages
Keywords acid mine drainage cost decontamination density discharge geochemistry hydrochemistry leaching lime metals mine dewatering neutralization pH pollution remediation sludge stability tailings toxicity viscosity waste disposal water treatment 22, Environmental geology
Abstract Lime neutralisation for the treatment of acid mine drainage is one of the oldest water pollution control techniques practised by the mineral industry. Several advances have been made in the process in the last thirty years, particularly with respect to discharge concentrations and sludge density. However, the impact of different treatment processes on metal leachability and sludge handling properties has not been investigated. A study of treatment sludges sampled from various water treatment plants has shown that substantial differences can be related to the treatment process and raw water composition. This study suggests that sludge densities, excess alkalinity, long-term compaction properties, metal leachability, crystallinity and cost efficiency can be affected by the neutralisation process and specific process parameters. The study also showed that the sludge density and dewatering ability is not positively correlated with particle size as previously suggested in numerous studies. The treatment process comparisons include sludge samples from basic lime treatment, the conventional High Density Sludge (HDS) Process, and the Geco HDS Process.
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Corporate Author Thesis
Publisher Place of Publication Sudbury Editor
Language Summary Language Original Title
Series Editor Series Title Mining and the Environment II Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes 2002-060865; Sudbury '99; Mining and the environment II--Sudbury '99; L'exploitation miniere et l'environnement, Sudbury, ON, Canada, Sept. 13-17, 1999 References: 10; illus. incl. 6 tables; GeoRef; English Approved no
Call Number CBU @ c.wolke @ 16574 Serial 473
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Author Dempsey, B.A.; Jeon, B.-H.
Title Characteristics of sludge produced from passive treatment of mine drainage Type Journal Article
Year 2001 Publication Geochem.-Explor. Environ. Anal. Abbreviated Journal
Volume 1 Issue (up) 1 Pages 89-94
Keywords acid mine drainage; aerobic environment; anaerobic environment; Appalachian Plateau; Appalachians; carbonate rocks; coagulation; compressibility; decontamination; density; drainage; filtration; geochemistry; Howe Bridge; Jefferson County Pennsylvania; limestone; mining geology; North America; passive systems; Pennsylvania; pH; pollution; ponds; rates; reclamation; sedimentary rocks; settling; sludge; slurries; suspended materials; United States; viscosity; wet packing density; wetlands; zeta-potential 22, Environmental geology
Abstract In the 1994 paper by Brown, Skousen & Renton it was argued that settleability and wet-packing density were the most important physical characteristics of sludge from treatment of mine drainage. These characteristics plus zeta-potential, intrinsic viscosity, specific resistance to filtration, and coefficient of compressibility were determined for several sludge samples from passive treatment sites and for several sludge samples that were prepared in the laboratory. Sludge from passive systems had high packing density, low intrinsic viscosity, low specific resistance to filtration and low coefficient of compressibility compared to sludge that was produced after addition of NaOH.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1467-7873 ISBN Medium
Area Expedition Conference
Notes Feb.; Characteristics of sludge produced from passive treatment of mine drainage; 2002-008382; References: 29; illus. incl. 5 tables United Kingdom (GBR); GeoRef; English Approved no
Call Number CBU @ c.wolke @ 5734 Serial 57
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Author Heal, K.V.; Salt, C.A.
Title Treatment of acidic metal-rich drainage from reclaimed ironstone mine spoil Type Journal Article
Year 1999 Publication Water Sci. Technol. Abbreviated Journal
Volume 39 Issue (up) 12 Pages 141-148
Keywords Acid mine drainage constructed wetland mine waste reclamation sewage sludge
Abstract Ironstone mine spoil leaves a legacy of land contamination and diffuse water pollution with acidic, metal-rich drainage. Reclamation for woodland may exacerbate water pollution due to spoil amendment and disturbance. Constructed wetland systems (CWS) are increasingly used for treating acid mine drainage but their performance is poorly understood. A combined approach was used to reclaim the Benhar ironstone spoil heap in Central Scotland. Trees have been planted in spoil treated with dried pelleted sewage sludge, limestone and peat. Spoil drainage (pH 2.7, 247 mg l-1 total Fe) passes through a CWS. Spoil throughflow, surface water chemistry and CWS performance were monitored for 12 months after reclamation. Acidity, Fe, Mn and Al concentrations declined in throughflow after reclamation, although this effect was not uniform. Soluble reactive P has been mobilised from the sewage sludge in residual areas of spoil acidity, but losses of other nutrients were short-lived. The CWS removes on average 33 % and 20-40 % of acidity and metal inputs but removal rates decrease in winter. Spoil reclamation has been successful in enabling vegetation establishment but has also increased Fe and Mn concentrations in surface drainage from the site, even after passage through the CWS.
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Notes Treatment of acidic metal-rich drainage from reclaimed ironstone mine spoil; Science Direct Approved no
Call Number CBU @ c.wolke @ 17272 Serial 45
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