Leaching optimization of mining wastes with lizardite and brucite contents for use in indirect mineral carbonation through the pH swing method

JOURNAL OF CLEANER PRODUCTION

卷:141

Article

Arce, Gretta L. A. F.^1,2  Neto, Turibio G. Soares¹  Avila, I.²  Luna, Carlos M. R.²  Carvalho, Joao A., Jr.² 

[1] INPE Natl Inst Space Res, Combust & Prop Associated Lab, Rodovia Presidente Dutra,Km 40, Cachoeira Paulista, SP, Brazil

[2] UNESP Univ Estadual Paulista, Dept Energy Combust & Carbon Capture Lab LC3, Guaratingueta Engn Campus, BR-12516410 Guaratingueta, SP, Brazil

关键词: Leaching;    Mining waste;    Lizardite;    Brucite;    Iron;    Mineral carbonation;   

DOI  :  10.1016/j.jclepro.2016.09.204

来源: Elsevier

【 摘 要 】

This study investigated the leaching process in order to maximize Mg and Fe extraction and to produce amorphous silica (SiO2) with high purity. For this, a mining waste identified as S-GO was employed; which is a serpentinite rock with high lizardite 1T and native brucite contents. A Taguchi Experiment Design was used in order to assess the parameters that influence the leaching process such as: granulometry, hydrochloric acid concentration (HCI), leaching temperature, and mass/volume ratio. Furthermore, thermogravimetric analysis (TGA) was done to understand the interrelation between the mineral structure and leaching performance. Results show that lizardite 1T-bearing serpentinite presents a low content of tetrahedral Al3+ and high octahedral Fe3+ contents on S-GO. Native brucite delayed the formation of a hydrated silica layer and improved dissolution of serpentines. For this, Mg and Fe extractions are efficient, reaching 88 2% of Mg and Fe extracted during the first 30 min of reaction, under mild process conditions: stoichiometric mass/volume ratio, 1M HCI concentration, pressure of 1 bar, temperature of 100 degrees C, and 300 gm particle size. On the other hand, an excess of acid improves Mg and Fe extraction by only 10 5% for S-GO. Such characteristics reduce energetic penalties and costs involved on indirect mineral carbonation processes by the pH swing method. (C) 2016 Elsevier Ltd. All rights reserved.

【 授权许可】

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