Froth properties and entrainment in lab-scale flotation: A case of carbonaceous sedimentary phosphate ore

• Published in: Chemical engineering research & design 2019-02, Vol.142, p.100-110
• Main Authors: Hoang, Duong Huu, Heitkam, Sascha, Kupka, Nathalie, Hassanzadeh, Ahmad, Peuker, Urs A., Rudolph, Martin
• Format: Article
• Language: English
• Subjects: Apatite; Automated mineralogy; Batch flotation; Dynamic froth analysis (DFA); Entrainment; Flotation; Froth flotation; Froth stability; Gangue; Mineralogy; Particle size; Properties (attributes); Rate constants; Reagents; Recovery
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2018.11.036

Flotation cell schematically represented as interacting pulp and froth zones in derivation of overall recovery and measuring the froth structure using DFA. [Display omitted] •Batch flotation of high-grade ores are significantly changing froth properties.•The effects governing in the froth with time and allow relating to existing models.•The froth and pulp properties should be incorporated in the entrainment modeling.•The analyses offer novel support for the understanding of entrainment phenomena. In flotation, the froth characteristics strongly influence the separation process as they are linked to water recovery, bubble size, entrainment of gangue particles, flotation rate constants and finally grade and recovery. In the case of a high-grade apatite ore with a high mass pull in lab-scale flotation, significant changes in pulp and froth properties occur, such that the froth stability decreases with increasing flotation time. These changes can be related to different particle and reagent concentrations. We describe the change of entrainment in a rich apatite ore batch flotation with time more precisely by measuring froth properties using a Dynamic Froth Analyzer (DFA). It is concluded that the degree of entrainment is not only dependent on particle size but also the pulp density due to its effect on particle settling and also froth properties in varying resistance to drainage. Through a combination of time-resolved dynamic froth analysis and automated mineralogy, we identify the dynamic effects governing in the froth and compare the entrainment results with existing models. Furthermore, our analyses offer novel support for the extension of the common understanding of the entrainment phenomena.