Evaluation of cryolite from pitinga (Amazonas-Brazil) as a source of hydrogen fluoride

Química Nova

Centro de Tecnologia Mineral, Rio de Janeiro, Brasil¹  Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil¹  Paulino, Jéssica F.¹  Neumann, Reiner¹  Afonso, Júlio C.¹ 

关键词:  cryolite;    hydrogen fluoride;    sulfuric acid;    acidic leaching;   

DOI  :  10.5935/0100-4042.20160049

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

This paper reports the use of cryolite from the Pitinga Mine (Amazonas state, Brazil) as raw material in hydrogen fluoride production. Samples were initially characterized by chemical and mineralogical analyses. They presented low silica content (< 4 wt.%). After milling, cryolite samples were digested with concentrated sulfuric acid under stirring (200 rpm) and variable temperature, time and liquid to solid ratio conditions. Under the best experimental conditions (140 °C, 3-5 h), 96 wt.% of fluorine was recovered as hydrogen fluoride. The application of a 23 full factorial design showed that temperature and reaction time were relevant parameters during leaching, whereas liquid to solid ratio was not statistically significant.

【 授权许可】

Unknown