Solidification/stabilization of zinc-lead tailings by alkali activated slag cement

Abstract

An appropriate proportion of alkali activated slag cement, abbreviated as AASC later, was determined based on strength test of paste specimens. Results showed that AASC prepared from 14% low modulus water glass and blast furnace slag presented its compressive strength of hardened cement paste of 69.6, 84.0 and 91.8 MPa at 3, 7, and 28 d curing ages respectively. Flowability of the fresh tailings-cement pastes and the strength development of hardened tailings-cement paste were also tested both in the cases with addition of AASC and Portland cement. The fresh tailings-cement paste added with AASC presented much better fl owability and the corresponding hardened paste presented higher compressive strength, especially the long term strength, than those added with Portland cement. Therefore, tailings paste added with AASC allowed lager solid content than that of Portland cement in order to keep the similar fl owability. SEM observation on the microstructure of the hardened tailings-AASC mixture pastes showed obvious cementation effect. MIP measurements also showed that the total porosity of the hardened tailings-cement pastes decreased, and the portion of larger pore also decreased when the dosage of AASC increased. It is believed that AASC is more suitable to be used as a binder for the stabilization of zinc-lead tailings and for its backfi lling operation than Portland cement. PAN Zhihua(潘志华): Prof.; Ph D;

Carbonation, Cementation, and Stabilization of Ultramafic Mine Tailings

“…Numerous tailings dam failures have occurred in recent years including those at the Mount Polley (Canada, 2014), Germano (Brazil, 2015), Córrego de Feijão (Brazil, 2019), and Cadia (Australia, 2018) mines and there remains serious risk of future failures. There are various approaches to stabilizing tailings including encouraging hardpan formation, − revegetation, and paste backfill. − For example, hardpan formation within the shallow tailings of the Nickel Rim Mine (Sudbury, Canada) in conjunction with a revegetation program aided in chemically stabilizing the tailings. , Characterized primarily by pyrrhotite (>98%), the tailings became cemented by the precipitation of goethite and jarosite within pore spaces. Revegetation has also been historically used to reduce wind erosion and physically stabilize tailings at the Copper Cliff Mine in Sudbury, Canada .…”

Compressive Strength Characteristics of Cemented Tailings Backfill with Alkali-Activated Slag

“…Sodium silicate is indeed a viscous material that is usually used to activate pozzolanic materials such as slag and fly ash. The chemical compound has many applications, namely, in waste treatment [27], mine tailings [28][29][30][31], sand fill [32], and other construction materials [33][34][35].…”

Synthesis and Hydration Characteristic of Geopolymer Based on Lead Smelting Slag

“…Because of these advantages, the geopolymer has found a variety of applications, such as transportation, industrial, agricultural, residential and mining [24][25][26]. Besides these, one of its major newer applications is in waste management, especially in the immobilization of toxic metals, such as Zn, Cu, Cd, Cr and Pb [27][28][29]. A geopolymer is defined as a synthetic alumino-silicate material and is generated from the reaction of solid alumino-silicate with a highly concentrated aqueous alkali hydroxide or silicate solution [17].…”