Chemical bleaching of the Brazilian kaolin: the effect of the pulp eletrochemical potential and pH adjustment

Quimica nova

Luz, Adão Benvindo da¹  Sampaio, João Alves¹  Silva, Fernanda Arruda Nogueira Gomes da²  Garrido, Francisco Manoel dos Santos²  Mello, Lívia da Silva²  Silva, Flávio Teixeira da²  Medeiros, Marta Eloísa² 

[1] Centro de Tecnologia Mineral, Rio de Janeiro, Brasil;Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil

关键词: kaolin;    chemical bleaching;    brightness.;   

DOI  :  10.1590/S0100-40422011000200017

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

Samples of Kaolinfrom different regions in Brazil were characterized by XRD, SEM and chemicalanalysis. A chemical bleaching study with pH adjustment was accomplished withthe fractions below 37 μm,after classification by screening. The main objective was to evaluate the conditionsof chemical bleaching that most increase the brightness of these kaolin's samples.Increases between 2.63 and 2.98% in the brightness (ISO) were observed afterthe chemical bleaching. We could say that the reduction of Fe3+ toFe2+ during the chemical bleaching promoted an increase in the brightness,based on the Pourbaix Diagrams.

【 授权许可】

CC BY