Comparison of Environmental Impacts of Deep-sea Tailings Placement Versus On-land Disposal

Abstract

With increasing metal prices and declining ore grades, new mines are getting larger and mine waste disposal and management have become more difficult, particularly from an environmental perspective. While technologies keep on improving, the available space for terrestrial mine waste disposal is limited. Thus, several coastal countries still consider deep-sea tailings placement (DSTP) as a viable option. This brief review compares the environmental impacts of DSTP versus on-land disposal and suggests several factors to consider in selecting the most suitable options for mine waste disposal.

Coastal waters contamination by mining tailings: What triggers the stability of iron in the dissolved and soluble fractions?

“…Considering the huge fluxes of dissolved Fe estimated here and the main role of sediment/tailings resuspension on the continental shelf, it is also worth to consider the role of submarine tailings disposal and deep‐sea tailings placement for dissolved metal release and consequent ocean enrichment (Ramirez‐Llodra et al 2015). Tailings disposal in marine shore was used in the 1970s and has been recently discussed as an alternative strategy to deal with land tailing disposal problems, including catastrophic rupture (Kwong et al 2019). Currently, there are 15 mines in activity using submarine tailings disposal or deep‐sea tailings placement whereas most of operations started in the past were closed and generated abandoned mine wastes along the coast (Ramirez‐Llodra et al 2015).…”

Submarine Tailings in Chile—A Review

“…The main problems include the footprint, land loss (useful in other activities), contamination of surface and groundwater, and the facilities' stability. There have been 138 significant failures recorded in mining tailings damps [68].…”

“…Kwong et al [68] compared the ecosystem impacts of onshore tailings versus tailings discharged in the sea. The advantages and disadvantages of both types of mining waste disposal are shown in Table 1 [69].…”

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

“…Mine tailings have historically been deposited in different ways, mainly focusing on the criteria of making transport, deposition, and storage as cost-effective as possible [ 2 ]. In the last century, when there were no environmental regulations, mine tailings were dumped into rivers, causing mine tailings migration to the sea [ 36 , 37 , 38 , 39 ]. In this way, a part of the mine tailings was deposited in the bed or banks of the rivers, on the beaches along the coast, and at the bottom of the sea [ 40 ].…”