ABSTRACT

Part I of this investigation, addressing two-phase systems, showed that etherdiamine produces more stable and dryer foams, whereas smaller bubbles are formed with faster kinetics by ethermonoamine. These remarkable differences in foam stability, attributed to the distinct chain length and consequent hydrophilic–lipophilic balance, influence froth properties, and may affect the selectivity of reverse cationic flotation of iron ores. The investigations conducted in this paper evaluated the effect of froth properties on the selective flotation recovery of a Brazilian iron ore from the Iron Quadrangle. The results showed that etherdiamine presented faster kinetics of froth formation but the recovery of water and solids in the froth was lower than that achieved with ethermonoamine. The water recovery was closely related to nonselective transport of solid particles in the froth by entrainment. The etherdiamine ability to form more stable and dryer froth reduced the entrainment of fine iron-bearing particles in the froth (tailings), improving the metal recovery in the concentrate (bulk), as the iron loss was directly proportional to the water recovery in the froth and the reagent presented lower entrainment factor than the ethermonoamine. In addition, the drier froth from etherdiamine is responsible for greater quartz true flotation, rendering this collector a more selective effect on flotation in spite the more powerful effect of ethermonoamine.

摘要

本研究的第一部分涉及两相系统，表明乙醚二胺产生更稳定和更干燥的泡沫，而乙醚单胺以更快的动力学形成较小的气泡。这些泡沫稳定性的显着差异，归因于不同的链长和随之而来的亲水-亲油平衡，影响泡沫性质，并可能影响铁矿石的反阳离子浮选的选择性。本文进行的调查评估了泡沫特性对从 Iron Quadrangle 中选择巴西铁矿石的浮选回收率的影响。结果表明，醚二胺具有更快的泡沫形成动力学，但泡沫中水和固体的回收率低于醚单胺。水的回收与泡沫中固体颗粒通过夹带的非选择性运输密切相关。醚二胺形成更稳定和更干燥的泡沫的能力减少了泡沫（尾矿）中细小的含铁颗粒的夹带，提高了精矿（散装）中的金属回收率，因为铁损与回收率成正比泡沫和试剂的夹带因子低于醚单胺。此外，来自乙醚二胺的干燥泡沫有助于提高石英的真浮选能力，尽管乙醚单胺的作用更强大，但这种捕收剂对浮选的选择性更强。提高精矿（散装）中的金属回收率，因为铁损与泡沫中的水回收率成正比，并且试剂的夹带因子低于醚单胺。此外，来自乙醚二胺的干燥泡沫有助于提高石英的真浮选能力，尽管乙醚单胺的作用更强大，但这种捕收剂对浮选的选择性更强。提高精矿（散装）中的金属回收率，因为铁损与泡沫中的水回收率成正比，并且试剂的夹带因子低于醚单胺。此外，来自乙醚二胺的干燥泡沫有助于提高石英的真浮选能力，尽管乙醚单胺的作用更强大，但这种捕收剂对浮选的选择性更强。