典型脉石矿物表面CN^(−)吸附规律及润湿性研究

Study on the Adsorption and Wettability ofCN−on the Surface of Typical Gangue Minerals

以石英、长石和方解石3种典型脉石矿物为吸附剂,NaCN为吸附质,考察了吸附时间和吸附剂添加量对CN^(−)吸附效果的影响。同时,采用固着液滴接触角检测法分析了脉石矿物表面吸附CN^(−)前后的润湿性差异,对吸附结果进行吸附动力学模型拟合。结果表明:石英、长石和方解石对CN^(−)表现出不同程度的吸附性和选择性。通过动力学研究发现:石英和长石对CN^(−)的吸附以物理吸附为主,CN^(−)与方解石之间存在键合吸附作用。通过检测接触角发现:CN^(−)的吸附导致脉石矿物表面亲水性增强,其中以石英表面接触角的降低最为明显。经过SBX浮选药剂作用后,脉石矿物表面接触角有所增加,但仍呈现亲水性质。说明氰化作用不会造成氰化渣浮选回收硫化矿时非目标矿物的跟浮,为实现氰化渣中矿物高效分离浮选提供了理论指导。

In recent years,with the continuous depletion of shallow mineral resources,there are many theoretical and practical studies on the recovery and utilization of sulfide ores in cyanide tailings.However,the existence of floatable gangue will hinder the recovery of sulfide ore in cyanide tailings.Therefore,it is very important to find out the adsorption mechanism of CN^(−)on the surface of gangue minerals and the change of surface wettability to identify the cause of low flotation recovery of cyanide tailings.In this paper,three typical gangue minerals,quartz,feldspar and calcite,were used as adsorbent,and NaCN was used as adsorbent.The influence of adsorption time and amount of adsorbent on the adsorption effect of CN^(−)were investigated.At the same time,the wettability difference before and after the adsorption of CN^(−)on the surface of gangue minerals was analyzed by using the contact angle detection method of solid droplet,and the adsorption kinetic model was fitted for the adsorption results.The results show that quartz,feldspar and calcite exhibit different degrees of adsorption and selectivity for CN^(−).When the mineral dosage was 5 g and the contact time was 12 h,the adsorption rate of CN^(−)tend to be stable.At this time,the adsorption rates of quartz,feldspar and calcite for CN^(−)are 43.9%,58.0%and 43.6%,respectively.Through kinetic study,it is found that the adsorption of CN^(−)by quartz and feldspar is mainly physical adsorption.There is binding adsorption between CN^(−) and calcite.Finally,according to the contact angle detection,the adsorption of CN^(−) resulted in the enhancement of the surfacehydrophilicity of gangue minerals,and the surface contact angles of quartz,feldspar and calcite decreased from38.5°,15.6° and 35.4° to 18.6°,14.4° and 20.6°.After the action of SBX flotation reagent,the surface contactangle of gangue minerals increase,but still showes hydrophilic properties. It shows that cyanidation will notcause the following flotation of non-target minerals when recovering sulfide ores from cyanide tailings flotation,which provides theoretical guidance for achieving efficient separation and flotation of metal sulfide ores incyanide tailings.