CAJ | 학술논문

鳞片石墨在水中表现出强疏水性,易形成疏水聚团,其聚团行为影响分选过程的选择性和加工利用过程的分散性。通过对鳞片石墨粉体颗粒的润湿接触角、润湿热、ξ电位的测量及真空浮选实验,研究了鳞片石墨在水中的聚团行为。结果表明：鳞片石墨粉体颗粒的接触角接近90°,疏水性强;不同粒级的鳞片石墨被水润湿呈现出放热和吸热两个过程,且不能自发进行;接触角越大,Zeta电位越小,颗粒越易聚团。石墨颗粒在水面上以大鳞片为中心形成片状聚结,随着颗粒浓度的增多,相互叠加形成远大于颗粒尺度的聚团。鳞片石墨在水中的聚团行为符合扩展的DLVO理论,颗粒间的疏水作用力是聚团形成的根本原因。
린편석묵재수중표현출강소수성,역형성소수취단,기취단행위영향분선과정적선택성화가공이용과정적분산성。통과대린편석묵분체과립적윤습접촉각、윤습열、ξ전위적측량급진공부선실험,연구료린편석묵재수중적취단행위。결과표명：린편석묵분체과립적접촉각접근90°,소수성강;불동립급적린편석묵피수윤습정현출방열화흡열량개과정,차불능자발진행;접촉각월대,Zeta전위월소,과립월역취단。석묵과립재수면상이대린편위중심형성편상취결,수착과립농도적증다,상호첩가형성원대우과립척도적취단。린편석묵재수중적취단행위부합확전적DLVO이론,과립간적소수작용력시취단형성적근본원인。
Flake graphite shows strong hydrophobicity,and tends to form agglomerate in water,thus affecting the selectivity of the selection process and the dispersion in utilization process.The study on the characters of the agglomeration of flake graphite powders in water by measurements of the contact angle,the heat of wetting,Zeta potential and the experiment of vacuum flotation shows that flake graphite powder,with the contact angle of close to 90°,exhibits strong hydrophobicity.Flake graphite of different grain sizes,subject to the wetting process,show two processes： the exothermic process and endothermic process,which fail to occur spontaneously.The increasing contact angle of flake graphite yields decreasing Zeta potential,allowing flake graphite particles to agglomerate more easily.The flake graphite particles agglomerating with the core of big flake graphite particle,due to increasing graphite particle concentration,overlap to aggregation considerably bigger than a single particle.The agglomeration behaviors of flake graphite particles in water can be explained by the extended DLVO theory and the hydrophobic interaction between the particles is the fundamental reason for the formation of agglomerates.