摘要
磁黄铁矿是铜、铅、锌和镍等有色金属硫化矿中常见的伴生矿物,其晶体化学性质复杂且表面易氧化,常对目的矿物的浮选分离造成干扰,因而成为选矿领域的难点之一。通过系统综述磁黄铁矿的结构与理化特性,重点分析了其氧化溶解机理及氧化产物对可浮性的影响规律;阐述了磁黄铁矿的抑制与活化,以及磁黄铁矿与黄药类捕收剂的相互作用机制;深入探讨了六方(非磁性)和单斜(磁性)磁黄铁矿在表面电性、氧化动力学及捕收剂吸附行为方面的差异,并阐明这些差异对其浮选行为的影响机制。明确了磁黄铁矿主要通过2种途径干扰浮选:一是消耗矿浆中的溶解氧;二是与共生硫化矿物发生电化学相互作用。在此基础上,进一步展望了磁黄铁矿浮选研究的未来方向:通过控制磁黄铁矿氧化过程、调控矿浆溶解氧含量以及调节磁黄铁矿与其他目的硫化矿物之间的电化学作用,实现对磁黄铁矿浮选的选择性抑制或活化。
Pyrrhotite is a prevalent gangue mineral found in non-ferrous sulfide ores,including those of copper,lead,and zinc.Its non-stoichiometric crystal structure,characterized by variable iron-to-sulfur(Fe/S)ratios,leads to complex crystal-chemical behavior.Additionally,the unstable bonding state at its surface makes it highly susceptible to oxidation when exposed to oxygen in the flotation pulp.These characteristics often impede the selective flotation separation of valuable minerals,presenting a significant challenge in the efficient recovery of non-ferrous metals.During the oxidation process,iron ions migrate from the bulk to the mineral surface,where they coordinate with O₂,OH⁻,and H₂O to form an outer layer of iron oxyhydroxide(FeOOH),while leaving behind an iron-depleted,sulfur-enriched sublayer.This process is influenced by the pulp’s pH and oxidation-reduction potential(Eh),leading to the progressive oxidation of monosulfide species within the sublayer to disulfides and polysulfides,thereby continuously altering the surface chemistry of pyrrhotite.Under mild oxidation conditions,surface metal-hydroxyl complexes are formed,which modify the surface charge and result in a positive zeta potential.In contrast,xanthate collectors are present in solution as negatively charged anions,which facilitates their electrostatic adsorption onto pyrrhotite.This interaction undermines the efficiency of depression and complicates the separation of pyrrhotite from target minerals.Under conditions of intensified oxidation,Fe(OH)₃precipitates form on the mineral surface.The pronounced hydrophilic nature of Fe(OH)₃results in the formation of a dense hydrophilic film,which markedly diminishes mineral floatability and significantly impedes the flotation of pyrrhotite.It is important to note that pyrrhotite primarily exists in two crystalline forms:non-magnetic hexagonal pyrrhotite and magnetic monoclinic pyrrhotite.The inherent crystallochemical differences between these forms result in distinct surface oxidation kinetics,surface electrical properties,and adsorption affinities for flotation reagents.Consequently,the two polymorphs exhibit differing flotation behaviors within the same flotation system,thereby substantially complicating the separation of valuable non-ferrous sulfide minerals.The detrimental impact of pyrrhotite on flotation separation is primarily exhibited through two mechanisms:(1)its oxidation process depletes dissolved oxygen(DO)in the pulp,which is crucial for the surface oxidation activation of target sulfide minerals during flotation;(2)galvanic interactions occur when pyrrhotite is in contact with other sulfides in the pulp,thereby modifying the surface chemistry of the associated minerals.In industrial applications,synergistic strategies can be implemented to selectively depress or activate pyrrhotite flotation.These strategies include controlling its oxidation rate by adjusting pH levels or adding antioxidants,regulating pulp DO through staged aeration or the use of redox modifiers,and modulating the electrochemical interactions between pyrrhotite and target sulfide minerals.
作者
刘晶
覃文庆
杨聪仁
LIU Jing;QIN Wenqing;YANG Congren(School of Minerals Processing&Bioengineering,Central South University,Changsha 410083,Hunan,China)
出处
《黄金科学技术》
北大核心
2026年第1期243-254,共12页
Gold Science and Technology
基金
国家自然科学基金项目“多晶型磁黄铁矿对铜锌硫化矿浮选的影响机制及调控”(编号:52474312)资助。
关键词
磁黄铁矿
超结构
表面氧化
抑制
活化
浮选
pyrrhotite
superstructure
surface oxidation
depression
activation
flotation
