(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 研究有無超聲波作用下Na3PO4分解白鎢礦的動力學(xué)。考察浸出溫度、Na3PO4濃度、NaOH濃度和礦物粒徑對白鎢礦浸出速率的影響。結(jié)果表明：超聲波場的引入加快了白鎢礦浸出過程中的反應(yīng)速率；超聲波場的作用使得浸出過程由擴散控制轉(zhuǎn)變?yōu)榛瘜W(xué)反應(yīng)控制，浸出反應(yīng)的表觀活化能也從78 kJ/mol降低至50 kJ/mol；在超聲波作用下反應(yīng)級數(shù)減小，NaOH的反應(yīng)級數(shù)由0.34降為0.07；而當Na3PO4濃度高于0.2 mol/kg后，其反應(yīng)級數(shù)從0.39減為0。
關(guān)鍵字: 白鎢礦；磷酸鈉；超聲波；浸出；動力學(xué)
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:The leaching kinetics of scheelite concentrates by sodium phosphate in the absence or presence of ultrasound was approached. The influences of leaching temperature, Na3PO4 concentration, NaOH concentration and particle size of mineral on the leaching rate of scheelite concentrate were investigated. The results show that ultrasound accelerates the leaching rate of the scheelite concentrate. The diffusion through the solid film is the rate limiting step in the decomposition process of scheelite concentrate in the absence of ultrasound. In the presence of ultrasound, the rate limiting step changes from the diffusion through solid film to the chemical reaction, and the apparent activation energy changes from 78 to 50 kJ/mol. Compared with the results in the absence or presence of ultrasound, the apparent reaction order of NaOH decreases from 0.34 to 0.07, and the apparent reaction order of Na3PO4 decreases from 0.39 to 0 when the concentration of Na3PO4 is up to 0.2 mol/kg.
Key words: scheelite concentrate; sodium phosphate; ultrasound; leaching; kinetics
