(中南大學(xué) 資源與生物工程學(xué)院，長沙 410083)
摘 要: 通過滑石純礦物實(shí)驗(yàn)，考查鈣離子作用下羧化殼聚糖對滑石可浮性影響。結(jié)果表明：滑石天然可浮性較好，在pH值為2~12時(shí)以MIBC為起泡劑進(jìn)行浮選，回收率均在90%以上；酸性條件下(pH＜5)羧化殼聚糖對滑石的抑制效果顯著，隨著pH值的升高羧化殼聚糖對滑石的抑制能力逐漸減弱。而鈣離子作用時(shí)，堿性條件下羧化殼聚糖對滑石的抑制效果顯著。結(jié)合吸附量和Zeta電位測試，溶液化學(xué)計(jì)算表明，在堿性條件下鈣離子溶解組分以Ca2+和Ca(OH)+的形式吸附在荷負(fù)電的滑石表面，并在滑石表面產(chǎn)生鈣位點(diǎn)，減小滑石與羧化殼聚糖之間的靜電斥力，促進(jìn)羧化殼聚糖在滑石表面吸附，實(shí)現(xiàn)羧化殼聚糖在弱堿性條件下對滑石的抑制。
關(guān)鍵字: 滑石；浮選；鈣離子；羧化殼聚糖
（School of Mineral Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The effect of carboxylation chitosan on the flotation behaviors of talc in the presence of calcium ions was investigated by micro-flotation tests. The flotation results show that the flotation recovery of talc is above 90% in the pH range of 2-11 using MIBC alone. The inhibiting effect of carboxylation chitosan is significant on talc flotation below pH 5, but is decreased in alkaline condition as the pH rose. When the talc is pretreated by calcium ions, the inhibiting effect of carboxylation chitosan on talc flotation in alkaline condition is significant. Combined with the results of absorption tests, zeta potential and solution calculation of calcium ions, it is indicated that the Ca2+ and Ca(OH)+ dissolved species of calcium ions absorbe on the negative surface of talc in alkaline condition, and generate calcium-binding sites, then decrease the electrostatic repulsion between talc and carboxylation chitosan, and improve the absorption of carboxylation chitosan on talc surface, thus depresse the talc under the condition of alkalescence.
Key words: talc; flotation; calcium ions; carboxylation chitosan
