功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2014年
5期
5102-5105,5111
,共5页
殷鹏飞%张蓉%李银冰%李宁%王佳佳%胡建昌
慇鵬飛%張蓉%李銀冰%李寧%王佳佳%鬍建昌
은붕비%장용%리은빙%리저%왕가가%호건창
超微粉体%荷电特性%气流粉碎%静电分散
超微粉體%荷電特性%氣流粉碎%靜電分散
초미분체%하전특성%기류분쇄%정전분산
micropowder%charging property%jet milling%electrostatic dispersion
气流粉碎作为超微粉体制备的一种先进技术被广泛运用在工业生产中,然而气流粉碎过程中颗粒间剧烈摩擦所形成的表面静电以及由于颗粒粒径减小所带来的强吸附性能,都将引起粉碎后的颗粒发生再次团聚,从而导致超微粉体的优良特性劣化。静电分散作为一种新型的物理分散法,通过使粉体颗粒在电晕电场中荷以同一极性的电荷,利用颗粒之间的库仑斥力进行分散,荷电量越大则粉体的分散性越好。以不同粒径的滑石粉为研究对象,对气流粉碎/静电分散相结合方法中粉体的荷电特性进行了实验研究。研究结果表明,平均粒径较大粉体的荷质比在较低气压下随着荷电电压的升高而增大,当气压较高时在40 kV下存在一峰值;而平均粒径较小粉体的荷质比均随着荷电电压的升高而增大。荷电电压恒定时滑石粉荷质比随着气流压强的增大而减小。相同荷电条件下粒径较小的粉体颗粒的荷电性能优于粒径较大颗粒。
氣流粉碎作為超微粉體製備的一種先進技術被廣汎運用在工業生產中,然而氣流粉碎過程中顆粒間劇烈摩抆所形成的錶麵靜電以及由于顆粒粒徑減小所帶來的彊吸附性能,都將引起粉碎後的顆粒髮生再次糰聚,從而導緻超微粉體的優良特性劣化。靜電分散作為一種新型的物理分散法,通過使粉體顆粒在電暈電場中荷以同一極性的電荷,利用顆粒之間的庫崙斥力進行分散,荷電量越大則粉體的分散性越好。以不同粒徑的滑石粉為研究對象,對氣流粉碎/靜電分散相結閤方法中粉體的荷電特性進行瞭實驗研究。研究結果錶明,平均粒徑較大粉體的荷質比在較低氣壓下隨著荷電電壓的升高而增大,噹氣壓較高時在40 kV下存在一峰值;而平均粒徑較小粉體的荷質比均隨著荷電電壓的升高而增大。荷電電壓恆定時滑石粉荷質比隨著氣流壓彊的增大而減小。相同荷電條件下粒徑較小的粉體顆粒的荷電性能優于粒徑較大顆粒。
기류분쇄작위초미분체제비적일충선진기술피엄범운용재공업생산중,연이기류분쇄과정중과립간극렬마찰소형성적표면정전이급유우과립립경감소소대래적강흡부성능,도장인기분쇄후적과립발생재차단취,종이도치초미분체적우량특성열화。정전분산작위일충신형적물리분산법,통과사분체과립재전훈전장중하이동일겁성적전하,이용과립지간적고륜척력진행분산,하전량월대칙분체적분산성월호。이불동립경적활석분위연구대상,대기류분쇄/정전분산상결합방법중분체적하전특성진행료실험연구。연구결과표명,평균립경교대분체적하질비재교저기압하수착하전전압적승고이증대,당기압교고시재40 kV하존재일봉치;이평균립경교소분체적하질비균수착하전전압적승고이증대。하전전압항정시활석분하질비수착기류압강적증대이감소。상동하전조건하립경교소적분체과립적하전성능우우립경교대과립。
Jet milling has been applied into many industries as an advanced technology in powder preparation. While the surface static electrons produced by friction between particles during grinding process and the strong adsorption property for particle size reduction will lead to agglomeration of the particles thus prepared,which offsets the advantages of micropowder to certain.Based on the Coulomb principle which states that particles car-rying charges of the same sign repel each other,the electrostatic dispersion was an innovative methodology which employs electrostatic effect to annihilate agglomeration,the more the charges carried by powder is,the better the dispersion of it was.In this paper,we proposed a new method to prepare micropowder with a combi-nation of j et milling and electrostatic dispersion techniques,and the charge-to-mass ratios of talc powders with different sizes have been measured experimentally.The results indicate that when the air pressure was lower, the charge-to-mass ratio of the talc with larger size increases with the increase of charging voltage,while it rea-ches the maximum at 40 kV when the air pressure was larger.But the charge-to-mass ratio of the talc with smaller size increases with the increase of charging voltage all the time.Besides,the charge-to-mass ratio of talc decreases with the increase of air pressure when the charging voltage was fixed,and the charging property of powder with smaller size was better compare to larger size under the same charging condition.