Recovery of magnesium sulfate and calcium sulfate from zinc flotation tailing

Raquel Húngaro Costa, University of São Paulo, Polytechnic School, Chemical Engineering Department, Rua do Lago, 250, Cidade Universitária, Butantã, 05508-030, São Paulo, Brazil.Follow
Jonathan Tenório Vinhal, University of São Paulo, Polytechnic School, Chemical Engineering Department, Rua do Lago, 250, Cidade Universitária, Butantã, 05508-030, São Paulo, Brazil.
Tatiana Scarazzato, University of São Paulo, Polytechnic School, Chemical Engineering Department, Rua do Lago, 250, Cidade Universitária, Butantã, 05508-030, São Paulo, Brazil
Denise Crocce Romano Espinosa, University of São Paulo, Polytechnic School, Chemical Engineering Department, Rua do Lago, 250, Cidade Universitária, Butantã, 05508-030, São Paulo, Brazil

Author ORCID Identifier

Raquel Húngaro Costa: 0000-0002-3314-9018

Jonathan Tenório Vinhal: 0000-0002-4391-2443

Tatiana Scarazzato: 0000-0002-9526-1937

Denise Crocce Romano Espinosa: 0000-0003-2359-9485

Abstract

Resource recovery is a process that has been used to obtain products from industrial waste. Mining tailings can be used as an alternative through ore beneficiation to create by-products for this type of waste. The work herein investigated the recovery of two products from a real tailing generated in the Zn beneficiation route in the flotation step. A non-magnetic fraction was submitted to a hydrometallurgical route to produce MgSO₄ and CaSO_4. Thermodynamic simulations using FactSage software were performed to evaluate the optimal leaching conditions varying the S:L ratio, the sulfuric acid concentration, and temperature. The best modeled conditions for pure dolomite were established in 1.2 mol×L^-1 H₂SO₄, S:L ratio 1:10, at room temperature, showing 100% Mg extraction. The simulation with the real composition showed 100% Mg extraction using 1.0 mol×L^-1 H₂SO_4, S:L ratio 1:10, at room temperature. Experimental leaching tests led to Mg and Ca extraction yields of 72% ±5 and 2%, respectively, obtained at 50°C in 35 min. The cementation step resulted in 92.3% of Cd removal from the leach liquor with Zn:Cd ratio of 100:1 in 5 min at 25°C. The obtained by-products were CaSO₄ and solubilized MgSO₄. Both are potentially usable for agriculture purposes, being magnesium sulfate a secondary macronutrient as fertilizer, and CaSO₄ as a soil conditioner.

Recommended Citation

Costa, Raquel Húngaro; Vinhal, Jonathan Tenório; Scarazzato, Tatiana; and Espinosa, Denise Crocce Romano (2025) "Recovery of magnesium sulfate and calcium sulfate from zinc flotation tailing," Journal of Sustainable Mining: Vol. 24 : Iss. 4 , Article 1.
Available at: https://doi.org/10.46873/2300-3960.1469