Submit to Special Issue Submit Abstract to Special Issue Review for Minerals Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Transforming Tailings into Dryland: Analyses, Technologies, and Strategies

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Minerals (ISSN 2075-163X).

Deadline for manuscript submissions: 1 August 2024 | Viewed by 5950

Share This Special Issue

Special Issue Editor

Dr. Alebachew Demoz

E-Mail Website
Guest Editor

CanmetENERGY, Natural Resources Canada, 1 Oil Patch Drive, Devon, AB T9G 1A8, Canada
Interests: fluid fine tailings treatment; geotechnics of tailings; multiphase rheological characterizations; instrumentation for process control and signal acquisition

Special Issue Information

Dear Colleagues,

In the face of anthropogenic climate change, industrialized nations have committed to net zero greenhouse gas (GHG) emissions by 2050, while other major nations plan to reach the same goal ten years later. An important component to accomplishing this goal is electrification, which utilizes more critical minerals, starting with generation to storage to transmission. Moreover, as developing nations catch up with modern lifestyles, the global demand for minerals is intensifying. Since only grams or kilograms of metals are extracted for each ton of ore processed, immense amounts of tailings are being produced. Tailings dams are an unavoidable part of mining operations, and their accumulation from current and past production occupies land that was forested and a habitat for wildlife. Along with GHG emissions, the drainage of chemicals used in the metallurgical processes to surface water is an unacceptable environmental hazard. For mining companies, dams pose major economic concerns as they require perpetual observation, construction, and maintenance to avoid structural failures.

Tailings’ storage will remain a prescient issue if mineral resources are not developed sustainably. Returning the tailing dam area to its original state in the form of dryland is the ideal goal in tailings’ management. Two intertwined challenges to the creation of dry land have been (1) the inordinately slow consolidation rate, and (2) the low load-bearing capacity of deposits of thickened fine tailings. Papers that address these challenges are welcome. Novel additives in the form of engineered clay geopolymers have features suited to address the issue of low deposit strengths. Applications of technologies such as volute scroll press, filtration, scroll decanter centrifuge separation, co-disposal, and similar that could produce thickened dry stackable treated tailings are part of this discussion. The physicochemical properties of the fines, particularly clay minerals, are determinant, and investigations that relate these properties to dewatering are also invited. The different states water distributes in tailings determine the extent of dewatering that can be achieved using mechanical methods, and experimental and theoretical investigations (i.e., application of double layer theory) are aspects of the physiochemical properties that can explain the challenge and actions necessary in the management of tailings. These are some of the topics, but characterization of tailings minerals and strategies that accelerate dewatering and shorten reclamation readiness of tailings are invited.

Dr. Alebachew Demoz
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

consolidation
dry stackable
mechanical dewatering
reclamation
shear strength
tailings

Published Papers (3 papers)

Download All Papers

Research

Jump to: Review

19 pages, 6683 KiB

Open AccessArticle

General Properties of Commingled Materials for Mix Designs

by David Barsi and G. Ward Wilson

Minerals 2024, 14(1), 30; https://doi.org/10.3390/min14010030 - 28 Dec 2023

Viewed by 957

Abstract

Tailings volumes continue to collectively increase worldwide, leading to larger dams and tailings management facilities. With numerous high-profile dam failures in the past decade, the risks of these management practices are also growing. A potential shift to waste management practices at mineral mines is to commingle waste rock and dewatered tailings. This blended material should have superior physical strength properties provided by the waste rock together with improved chemical stability characteristics associated with the low permeability of the tailings. Ideally, commingled tailings and waste rock can be used to construct various mined earth landforms that are both physically and chemically stable, which will enhance operational performance and ultimately provide for the sustainable decommissioning and closure of the mining facility. To study these materials, the University of Alberta Geotechnical Centre is working with global industry partners to test commingled materials from several mine sites with varying ore and host rock types and climate regimes. The first stage of this study is described here and is focused on the optimum density, saturated hydraulic conductivity, and soil–water characteristic curves of various blend ratios, performed at laboratory scale. Full article

(This article belongs to the Special Issue Transforming Tailings into Dryland: Analyses, Technologies, and Strategies)

► Show Figures

Figure 1

16 pages, 4873 KiB

Open AccessArticle

Accelerating the Consolidation of Thickened Tailings Using Sand Co-Disposal

by Alebachew Demoz

Minerals 2023, 13(10), 1277; https://doi.org/10.3390/min13101277 - 29 Sep 2023

Cited by 1 | Viewed by 900

Abstract

Only grams or kilograms of valuable resources are extracted for each tonne of ore processed, generating immense amounts of tailings. Returning tailings-containment dams to their equivalent pre-disturbance landscape state is many stakeholders’ acceptable management strategy. The depositing of thickened fluid fine tailings (FFT), which the industry has relied upon to develop geotechnically stable dry landscapes, has not materialised due to the low hydraulic conductivity of such placements. The addition of sand to thickened FFT is proposed to accelerate the consolidation of thickened FFT in a co-disposal scheme, and this study evaluates its impact. In the continuum of solid wastes from mining operations, sand is the next-larger-sized grade of solids after “fine” that is produced in high proportions. Blends of highly-plastic FFT and fine-grade sand tailings at varying sand-to-fine ratio (SFR) values were tested. Sand lowered the liquid limit but did not significantly affect the plastic limit of FFT. The changes in liquid and plastic limits for SFR ≥ 1 blends were under 5% of water content. The maximum unit weight for the co-disposal mixes was obtained at SFR 3. Despite increases in unit weights, hydraulic conductivity increased with increasing SFR, while the trend for compression rates was in the reverse order. Void ratio—effective pressure—hydraulic conductivity power law relationships at varying SFR were obtained from the consolidation measurements. The constitutive constants of these relationships were used to model settlement of 30 m deep pits over a 25-year period. For all the deposits studied, the dewatering converged to a maximum solids content characteristic of each SFR in the order 74, 85, 88, and 94% (w/w) for thickened FFT and SFRs 1, 2, and 3, respectively. The numerically calculated average solid contents of the deep-pit placements grew closer with increasing SFR becoming 59, 77, 82, and 86% (w/w), respectively. Balancing the consolidation-rate gains and the land footprint required for storage with SFR increase, the optimal composition for co-disposal for this material and similar tailings is SFR 1. Full article

(This article belongs to the Special Issue Transforming Tailings into Dryland: Analyses, Technologies, and Strategies)

► Show Figures

Figure 1

Review

Jump to: Research

30 pages, 15532 KiB

Open AccessReview

Dry Stacking of Filtered Tailings for Large-Scale Production Rates over 100,000 Metric Tons per Day: Envisioning the Sustainable Future of Mine Tailings Storage Facilities

by Carlos Cacciuttolo and Edison Atencio

Minerals 2023, 13(11), 1445; https://doi.org/10.3390/min13111445 - 16 Nov 2023

Cited by 2 | Viewed by 3258

Abstract

Communities and authorities have been dismayed by globally recorded tailings storage facility (TSF) failures in recent years, which have negatively affected the safety of people and the integrity of the environment. In this context, obtaining the social and environmental license to operate TSFs has become a challenging process for mining companies. This has promoted the trend of using mine tailings dewatering technologies in the mining industry, with dry stacking of filtered mine tailings being recognized worldwide as one of the most acceptable, safe, and environmentally friendly solutions. This article presents a new paradigm in managing mine tailings, with disruptive and futuristic characteristics, considering the dry stacking of filtered mine tailings for large-scale industrial production rates over 100,000 metric tons per day (mtpd). Aspects of filtered tailings management are discussed, such as (i) dewatering process plant with thickening/filtering equipment, (ii) conveyance using fixed and movable conveyor belts, (iii) construction of dry stacking of filtered mine tailings facility, and (iv) implementation of Industry 4.0 technologies for automation of the mining processes. Finally, the article discusses how the large-scale filtered mine tailings solution is applied, considering the advances in the equipment’s performance and implementation of Industry 4.0 technologies as well as the experience gained worldwide in several mining operations. The future global trend is that mining operations with high daily production of mine tailings will apply dry stacking technology without dams to guarantee sustainability, promote continuity of the mining business, ensure the safety of communities, and conserve the environment. Full article

(This article belongs to the Special Issue Transforming Tailings into Dryland: Analyses, Technologies, and Strategies)

► Show Figures