Pub Date : 2019-05-08DOI: 10.36487/ACG_REP/1910_0.04_LIEFFERINK
M. Liefferink
For most of its history, the mining industry in South Africa has not been subjected to comprehensive environmental regulation. In recent years, however, this has changed significantly, and the industry is now required to comply with a complex web of mining and environmental policy and legislation. Despite these regulatory advances, we still grapple with legacy issues, namely how to manage decades of environmental degradation, mining waste and long-term residual and latent impacts and how to equitably and fairly apportion duties, responsibilities and liabilities for the remediation of mining waste. An analysis of the Witwatersrand gold fields and the management of its uraniferous waste provides an excellent example of the complexity of these issues and lessons learnt.
{"title":"Selected extracts from South Africa’s environmental legislation: challenges with the management of gold tailings within the Witwatersrand gold fields and case studies","authors":"M. Liefferink","doi":"10.36487/ACG_REP/1910_0.04_LIEFFERINK","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_0.04_LIEFFERINK","url":null,"abstract":"For most of its history, the mining industry in South Africa has not been subjected to comprehensive environmental regulation. In recent years, however, this has changed significantly, and the industry is now required to comply with a complex web of mining and environmental policy and legislation. \u0000Despite these regulatory advances, we still grapple with legacy issues, namely how to manage decades of environmental degradation, mining waste and long-term residual and latent impacts and how to equitably and fairly apportion duties, responsibilities and liabilities for the remediation of mining waste. \u0000An analysis of the Witwatersrand gold fields and the management of its uraniferous waste provides an excellent example of the complexity of these issues and lessons learnt.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78988483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-08DOI: 10.36487/ACG_REP/1910_20_VIETTI
A. Vietti, Sl Rabie, K. Ntshabele
Portions of this paper were originally published in ‘A strategy for improving water recovery in kimberlitic diamond mines’ as it appeared in the February 2019 Edition of the SAIMM Journal, Volume 119 published by The Southern African Institute of Mining and Metallurgy. Mine site location and the sources from which raw water is drawn are fixed by geology, geography and climate. The colloidal behaviour of the tailings is therefore randomly determined by the tailings mineralogy and the chemical characteristics of the process water circuit. In some fortunate cases, the tailings slurries are non-dispersive and solid/liquid separation, either by gravity thickening or filtration, is easily achieved at low capital and operating cost. In less fortunate cases the tailings are highly dispersive and solid/liquid separation is achieved only at high capital and operating cost. This paper presents a strategy by which difficult-to-treat slurries can be modified by conditioning the process water circuit with a process water conditioner (ClariVie44®) so that gravity thickening and filtration can be enhanced.
{"title":"Process water conditioning to improve slurry dewatering","authors":"A. Vietti, Sl Rabie, K. Ntshabele","doi":"10.36487/ACG_REP/1910_20_VIETTI","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_20_VIETTI","url":null,"abstract":"Portions of this paper were originally published in ‘A strategy for improving water recovery in kimberlitic diamond mines’ as it appeared in the February 2019 Edition of the SAIMM Journal, Volume 119 published by The Southern African Institute of Mining and Metallurgy. \u0000Mine site location and the sources from which raw water is drawn are fixed by geology, geography and climate. The colloidal behaviour of the tailings is therefore randomly determined by the tailings mineralogy and the chemical characteristics of the process water circuit. \u0000In some fortunate cases, the tailings slurries are non-dispersive and solid/liquid separation, either by gravity thickening or filtration, is easily achieved at low capital and operating cost. In less fortunate cases the tailings are highly dispersive and solid/liquid separation is achieved only at high capital and operating cost. \u0000This paper presents a strategy by which difficult-to-treat slurries can be modified by conditioning the process water circuit with a process water conditioner (ClariVie44®) so that gravity thickening and filtration can be enhanced.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88825381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-08DOI: 10.36487/ACG_REP/1910_19_TORRES_LOPEZ
C. T. Lopez, M. Catling, J. Bellwood, L. Boxill
Improving the dewatering characteristics of high solids tailings streams, by the addition of high molecular weight anionic polyacrylamides is known to be operationally challenging. This is particularly true in applications where a secondary flocculation occurs after primary treatment and thickening of a tailings stream – for example, underflow from a thickener or the dredging and re-treatment of unconsolidated material from a tailings dam. Previous experience has shown that high dosages of polymer are often required to increase the initial water release from the tailings on deposition and improve the longer-term consolidation of the deposit. This paper investigates the effect of preconditioning high solids tailings through the use of shear prior to flocculation with the aim of both reducing the overall polymer dose and improving the dewatering performance of the deposit. Data presented includes the effect of preconditioning on slurry rheology and initial water release of the polymer treated material. The work showed that in some circumstances, improvements may be achieved by applying an optimised level of pre-shear, but this is dependent upon the type and properties of the tailings. This study was undertaken on tailings slurries, from different mineral types, that have varying levels of clay and overall solids content.
{"title":"The effect of preconditioning of tailings prior to inline flocculation and deposition","authors":"C. T. Lopez, M. Catling, J. Bellwood, L. Boxill","doi":"10.36487/ACG_REP/1910_19_TORRES_LOPEZ","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_19_TORRES_LOPEZ","url":null,"abstract":"Improving the dewatering characteristics of high solids tailings streams, by the addition of high molecular weight anionic polyacrylamides is known to be operationally challenging. This is particularly true in applications where a secondary flocculation occurs after primary treatment and thickening of a tailings stream – for example, underflow from a thickener or the dredging and re-treatment of unconsolidated material from a tailings dam. Previous experience has shown that high dosages of polymer are often required to increase the initial water release from the tailings on deposition and improve the longer-term consolidation of the deposit. \u0000This paper investigates the effect of preconditioning high solids tailings through the use of shear prior to flocculation with the aim of both reducing the overall polymer dose and improving the dewatering performance of the deposit. Data presented includes the effect of preconditioning on slurry rheology and initial water release of the polymer treated material. The work showed that in some circumstances, improvements may be achieved by applying an optimised level of pre-shear, but this is dependent upon the type and properties of the tailings. This study was undertaken on tailings slurries, from different mineral types, that have varying levels of clay and overall solids content.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86342247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-08DOI: 10.36487/ACG_REP/1910_08_SPAGNOLI
G. Spagnoli, F. Clément, Belay Zeleke Dilnesa, Fenghua Cao, P. Feng
Tailings are the materials left over after the process of separating the valuable fraction of ore from the gangue. Tailings ponds are engineered structures created using dams, berms and natural features such as valleys, hillsides or depressions. The pumping of tailings slurry into a pond allows the sedimentation of solids from the water. Tailings ponds can be highly toxic because they are used to store harmful waste made from separating minerals from rocks or the slurry produced from tar sands mining. To minimise contamination of underlying groundwater, high-density polyethylene (HDPE) liners are used. These liners are prefabricated sheets that are welded onsite to form a continuous waterproofing membrane that prevents the migration of contaminated water into the environment. Despite their widespread application, HDPE liners have inherent performance limitations, such as leakages at the location of welds, UV resistance, maintenance and repair. This paper considers a new type of sprayable reactive membrane as a waterproofing structure. Permeability tests with the Rowe cell, chemical and durability tests (interaction with water and leachates at different temperatures, oxidation and UV resistance tests) and mechanical tests (tensile strength tests, elongation tests, puncture tests) were performed and compared with conventional HDPE membranes for tailing ponds. Results showed that the new sprayable membrane has good performance comparable with the conventional HDPE membrane and it can be a very attractive solution for tailings ponds liners.
{"title":"A new waterproofing membrane for tailings ponds","authors":"G. Spagnoli, F. Clément, Belay Zeleke Dilnesa, Fenghua Cao, P. Feng","doi":"10.36487/ACG_REP/1910_08_SPAGNOLI","DOIUrl":"https://doi.org/10.36487/ACG_REP/1910_08_SPAGNOLI","url":null,"abstract":"Tailings are the materials left over after the process of separating the valuable fraction of ore from the gangue. Tailings ponds are engineered structures created using dams, berms and natural features such as valleys, hillsides or depressions. The pumping of tailings slurry into a pond allows the sedimentation of solids from the water. Tailings ponds can be highly toxic because they are used to store harmful waste made from separating minerals from rocks or the slurry produced from tar sands mining. To minimise contamination of underlying groundwater, high-density polyethylene (HDPE) liners are used. These liners are prefabricated sheets that are welded onsite to form a continuous waterproofing membrane that prevents the migration of contaminated water into the environment. Despite their widespread application, HDPE liners have inherent performance limitations, such as leakages at the location of welds, UV resistance, maintenance and repair. This paper considers a new type of sprayable reactive membrane as a waterproofing structure. Permeability tests with the Rowe cell, chemical and durability tests (interaction with water and leachates at different temperatures, oxidation and UV resistance tests) and mechanical tests (tensile strength tests, elongation tests, puncture tests) were performed and compared with conventional HDPE membranes for tailing ponds. Results showed that the new sprayable membrane has good performance comparable with the conventional HDPE membrane and it can be a very attractive solution for tailings ponds liners.","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82190959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Café s in Asia","authors":"Emma Felton","doi":"10.4324/9781315225869-6","DOIUrl":"https://doi.org/10.4324/9781315225869-6","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75729216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-07DOI: 10.4324/9781315225869-10
Emma Felton
{"title":"Afterword","authors":"Emma Felton","doi":"10.4324/9781315225869-10","DOIUrl":"https://doi.org/10.4324/9781315225869-10","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82501901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Coffee business","authors":"Emma Felton","doi":"10.4324/9781315225869-4","DOIUrl":"https://doi.org/10.4324/9781315225869-4","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87933574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The café and the city","authors":"Emma Felton","doi":"10.4324/9781315225869-2","DOIUrl":"https://doi.org/10.4324/9781315225869-2","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90777782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The exported café","authors":"Emma Felton","doi":"10.4324/9781315225869-5","DOIUrl":"https://doi.org/10.4324/9781315225869-5","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77152131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The café","authors":"Emma Felton","doi":"10.4324/9781315225869-3","DOIUrl":"https://doi.org/10.4324/9781315225869-3","url":null,"abstract":"","PeriodicalId":20480,"journal":{"name":"Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74335617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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