(中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 以油酸鈉為捕收劑，考察了攪拌預(yù)處理引起的鋁離子溶出對微細(xì)粒一水硬鋁石浮選行為的影響。浮選結(jié)果表明：添加少量鋁離子能促進(jìn)礦物浮選，添加鋁離子濃度大于1×10-5 mol/L后，礦物可浮性逐漸降低；短時(shí)間攪拌預(yù)處理可提高浮選回收率，攪拌時(shí)間大于10 min后，浮選效果逐漸變差。ICP、吸附量、接觸角測定結(jié)果和浮選溶液化學(xué)分析表明：鋁離子添加量較小時(shí)，溶液中鋁離子主要形成羥基絡(luò)合物，促進(jìn)油酸鈉吸附，增強(qiáng)礦物疏水性；鋁離子添加量較大時(shí)，親水性氫氧化物沉淀逐漸增多，礦物疏水性變差，可浮性降低。Zeta電位和粒度測試結(jié)果表明：攪拌預(yù)處理后，顆粒表面負(fù)電性降低、粒度變粗，這說明顆粒形成絮團(tuán)。適宜條件下攪拌預(yù)處理有助于絮團(tuán)生長，這也是攪拌預(yù)處理相比于直接添加鋁離子能夠獲得更高浮選回收率的重要原因。
關(guān)鍵字: 攪拌預(yù)處理；一水硬鋁石；微細(xì)粒浮選；離子溶出；疏水聚團(tuán)
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The objective of this study was to assess the effect of Al3+ dissolution induced by pre-agitation on the flotation of ultra-fine diaspore with the addition of NaOl. The results of flotation tests show that the addition of a small amount of Al3+ into the pulp is helpful for flotation, however, after Al3+concentration is higher than 1×10-5 mol/L, the addition of Al3+ has a detrimental effect on flotation. A short time of pre-agitation can improve the recovery of diaspore, while the recovery decreases gradually when the miners are agitated more than 10 min. ICP measurements, adsorption capacity measurements, contact angle measurements and the analysis results of flotation solution chemistry show that Al3+ exists mainly as a form of hydroxy complexes in solution with a small additive quantity, which promotes the adsorption of NaOl on the mineral surface and enhances the hydrophobicity of diaspore. With a big additive quantity, the amount of hydrophilic hydroxide precipitation increases gradually, and the hydrophobicity of minerals becomes worse so that the floatability is decreased. Zeta potential measurements and particle size measurements show that the electronegativity of particles decreases and the particle size increases after pre-agitation, the results indicate the formation of flocculation. Compared with the direct addition of Al3+, an appropriate pre-agitation is beneficial to the formation of hydrophobic flocculation in pre-agitation, which is also an important reason for the higher recovery.
Key words: pre-agitation; diaspore; ultra-fine particle flotation; ions dissolution; hydrophobic flocculation
