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

Química Nova

Silva, Fernanda Arruda Nogueira Gomes da¹  Luz, Adão Benvindo da¹  Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil¹  Centro de Tecnologia Mineral, Rio de Janeiro, Brasil¹  Garrido, Francisco Manoel dos Santos¹  Mello, Lívia da Silva¹  Silva, Flávio Teixeira da¹  Medeiros, Marta Eloísa¹  Sampaio, João Alves¹ 

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 Kaolin from different regions in Brazil were characterized by XRD, SEM and chemical analysis. A chemical bleaching study with pH adjustment was accomplished with the fractions below 37 μm, after classification by screening. The main objective was to evaluate the conditions of 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 after the chemical bleaching. We could say that the reduction of Fe3+ to Fe2+ during the chemical bleaching promoted an increase in the brightness, based on the Pourbaix Diagrams.

【 授权许可】

Unknown