An Alternative Technology to Obtain Dewatered Mine Tailings: Safe and Control Environmental Management of Filtered and Thickened Copper Mine Tailings in Chile

Abstract

An alternative process to obtain a high degree of dewatering tailings that produces a high-density product is presented in this article. This technology involves the combination of tailings particle grain size classification by hydrocyclones (HC) and tailings dewatering by horizontal vibratory screens (HVS). It makes it possible to dewater tailings to a high grade of performance. This alternative technology (HC-HVS) involves the recovery of water from the coarse fraction of tailings (sands) through two hydrocycloning stages, followed by a dewatering stage of cycloned tailings sands on horizontal vibratory screens, to reduce moisture content and turn it into a “cake “. The resulting coarse fraction tailings are easily transported to a dry stack tailings storage facility (TSF). The fine fraction of tailings (slimes) can be dewatered on thickener equipment to recover part of the process water. Finally, this article describes the main benefits of this alternative dewatered tailings technology with an emphasis on (i) dewatering technology evolution over the last 17 years; (ii) process stages features; (iii) pilot test results; (iv) tailings properties analysis (such as particle grain size distribution, fines content) and (v) lessons learned about the experience gained in the operation of Mantos Blancos case study with dry stack tailings storage facility.

Towards a Circular Economy in the Mining Industry: Possible Solutions for Water Recovery through Advanced Mineral Tailings Dewatering

“…These dewatered mine tailings are then collected from the screens and either directed to a designated collection area or conveyed for disposal or further processing. This method offers several advantages in terms of efficiency and water recovery, making it an appealing option for certain mining operations [158]. Gomes et al [159] conducted a study on the combination of hydrocyclone particle classification and various dewatering techniques, including screening, thickening, and filtering, to dewater iron mine tailings at a pilot scale.…”

“…This suggests its appeal for environmentally conscious tailings management and maximizing water recovery. However, while HC-HVS technology shows potential for dewatering non-fine and low-plasticity tailings, concerns arise about its scalability for larger production operations exceeding 25,000 metric tons per day [158].…”

Socio-Environmental Risks Linked with Mine Tailings Chemical Composition: Promoting Responsible and Safe Mine Tailings Management Considering Copper and Gold Mining Experiences from Chile and Peru

“…Tailings from the third cleaner report to the second cleaner and tailings from the second cleaner report to the first cleaner. The generated mine tailings flow by gravity to the tailings thickener for water recovery and final disposal in the TSF [ 9 ] ( Figure 9 ).…”

“…Important differences distinguishing mine tailings from the other mentioned mining wastes are: (i) particle size, with mine tailings having a fine granulometry composed of sand, silt, and clay; (ii) the presence of chemical reagents from the metallurgical process; and (iii) management via the use of water for transportation. Mine tailings may or may not be mixed with the process water that remains after the metallurgical treatment of ore, ore concentrate, or extracted materials to obtain marketable components such as metals or minerals [ 9 ]. Mine tailings material may contain ground rock, sand, clay, chemicals from the metallurgical process, and residual metals, minerals, and sulfides [ 10 ].…”

Low-Cost Sensors Technologies for Monitoring Sustainability and Safety Issues in Mining Activities: Advances, Gaps, and Future Directions in the Digitalization for Smart Mining

“…An important case to mention related to mining activity has been the shocking consequences of some failures of mine tailings storage facilities registered in the last decades, generating impacts and environmental damage, destruction of population centers, and deaths of human beings [ 25 , 26 ]. Some historical examples of these mine tailings storage facilities failures are: (i) Los Frailes, Spain, 1998, (ii) Baia Mare, Romania, 2000 (iii) Kolontar, Hungary, 2010, (iv) Mount Polley, Canada, 2014, (v) Fundao Samarco, Brazil, 2015, (vi) Brumadinho, Brazil, 2019, (vii) Jagersfontain, South Africa, 2022, and (viii) Williamson, Tanzania, 2022 [ 20 , 27 ].…”