Cargando…
Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings
In areas where access to water for mineral processing is limited, the direct use of seawater in processing has been considered as an alternative to the expense of its desalination. However, efficient flotation of copper sulfides from non-valuable phases is best achieved at a pH > 10.5, and raisin...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8777806/ https://www.ncbi.nlm.nih.gov/pubmed/35054745 http://dx.doi.org/10.3390/polym14020339 |
_version_ | 1784637155603120128 |
---|---|
author | Jeldres, Matías Toro, Norman Gallegos, Sandra Robles, Pedro Salazar, Iván Fawell, Phillip D. Jeldres, Ricardo I. |
author_facet | Jeldres, Matías Toro, Norman Gallegos, Sandra Robles, Pedro Salazar, Iván Fawell, Phillip D. Jeldres, Ricardo I. |
author_sort | Jeldres, Matías |
collection | PubMed |
description | In areas where access to water for mineral processing is limited, the direct use of seawater in processing has been considered as an alternative to the expense of its desalination. However, efficient flotation of copper sulfides from non-valuable phases is best achieved at a pH > 10.5, and raising the pH of seawater leads to magnesium precipitates that adversely affect subsequent tailings dewatering. Seawater pre-treatment with lime can precipitate the majority of magnesium present, with these solids then being removed by filtration. To understand how such treatment may aid tailings dewatering, treated seawater (TSw) was mixed with raw seawater (Rsw) at different ratios, analyzing the impact on the flocculated settling rate, aggregate size as measured by focused beam reflectance measurement (FBRM), and vane yield stress for two synthetic clay-based tailings. A higher proportion of Tsw (10 mg/L Mg(2+)) led to larger aggregates and higher settling rates at a fixed dosage, with FBRM suggesting that higher calcium concentrations in Tsw may also favor fines coagulation. The yield stress of concentrated suspensions formed after flocculation decreased with higher proportions of Tsw, a consequence of lower flocculant demand and the reduced presence of precipitates; while the latter is a minor phase by mass, their high impact on rheology reflects a small particle size. Reducing magnesium concentrations in seawater in advance of use in processing offers advantages in the water return from thickening and subsequent underflow transport. However, this may not require complete removal, with blending Tsw and Rsw an option to obtain acceptable industrial performance. |
format | Online Article Text |
id | pubmed-8777806 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-87778062022-01-22 Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings Jeldres, Matías Toro, Norman Gallegos, Sandra Robles, Pedro Salazar, Iván Fawell, Phillip D. Jeldres, Ricardo I. Polymers (Basel) Article In areas where access to water for mineral processing is limited, the direct use of seawater in processing has been considered as an alternative to the expense of its desalination. However, efficient flotation of copper sulfides from non-valuable phases is best achieved at a pH > 10.5, and raising the pH of seawater leads to magnesium precipitates that adversely affect subsequent tailings dewatering. Seawater pre-treatment with lime can precipitate the majority of magnesium present, with these solids then being removed by filtration. To understand how such treatment may aid tailings dewatering, treated seawater (TSw) was mixed with raw seawater (Rsw) at different ratios, analyzing the impact on the flocculated settling rate, aggregate size as measured by focused beam reflectance measurement (FBRM), and vane yield stress for two synthetic clay-based tailings. A higher proportion of Tsw (10 mg/L Mg(2+)) led to larger aggregates and higher settling rates at a fixed dosage, with FBRM suggesting that higher calcium concentrations in Tsw may also favor fines coagulation. The yield stress of concentrated suspensions formed after flocculation decreased with higher proportions of Tsw, a consequence of lower flocculant demand and the reduced presence of precipitates; while the latter is a minor phase by mass, their high impact on rheology reflects a small particle size. Reducing magnesium concentrations in seawater in advance of use in processing offers advantages in the water return from thickening and subsequent underflow transport. However, this may not require complete removal, with blending Tsw and Rsw an option to obtain acceptable industrial performance. MDPI 2022-01-16 /pmc/articles/PMC8777806/ /pubmed/35054745 http://dx.doi.org/10.3390/polym14020339 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Jeldres, Matías Toro, Norman Gallegos, Sandra Robles, Pedro Salazar, Iván Fawell, Phillip D. Jeldres, Ricardo I. Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title | Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title_full | Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title_fullStr | Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title_full_unstemmed | Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title_short | Reducing Magnesium within Seawater Used in Mineral Processing to Improve Water Recovery and Rheological Properties When Dewatering Clay-Based Tailings |
title_sort | reducing magnesium within seawater used in mineral processing to improve water recovery and rheological properties when dewatering clay-based tailings |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8777806/ https://www.ncbi.nlm.nih.gov/pubmed/35054745 http://dx.doi.org/10.3390/polym14020339 |
work_keys_str_mv | AT jeldresmatias reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT toronorman reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT gallegossandra reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT roblespedro reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT salazarivan reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT fawellphillipd reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings AT jeldresricardoi reducingmagnesiumwithinseawaterusedinmineralprocessingtoimprovewaterrecoveryandrheologicalpropertieswhendewateringclaybasedtailings |