(1)Semi-pilot and Pilot Tests for the Design of a Thickened Tailings System

摘要

Commonly in Chile and around the world, existing mining operations and new mining projectshave had to adapt to the limited availability and increasing restrictions of water resources, as wellas the reduction of usable tailings disposal areas and environmental demands. In several projects,trade-off studies have determined that high density thickening or paste technologies, are the bestconceptual solution for tailings storage. For current conventional thickened tailings operations,studies are usually discussed to assess the possibility of converting into a thickened or paste tailingsoperations.When the adaptation to high density thickened tailings is evaluated, a key aspect is to determinethe tailings test matrix to collect reliable characterization data in order to identify the best technicaland economical option for the tailings management system. Also, the test plan must provideinformation to support the selection of equipment and estimating both capital and operating costs.The authors conducted a semi-pilot and pilot test plan on three samples of tailings from a largecopper mine in northern Chile, which reviewed the physicochemical, sedimentation and rheologycharacterization, and beach slope prediction of the thickened tailings. The results of these tests wereused to consolidate design criteria, make a preselection of equipment and to discriminate betweenthe use of seawater or desalinated water for the process. A further review of the conceptual solutionproposed in earlier trade-off studies, is considered as a part of the next feasibility study.This paper details the tests, analysis, conclusions and thickening equipment selection made on thebasis of semi-pilot and pilot tests developed, and the comparison with laboratory test campaignsconducted in the previous phase of the project. It also emphasizes the conclusions on therelationship between design parameters and specific test work.