(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 研究醚類添加劑B35對(duì)鋁酸鈉溶液晶種分解過程的影響，采用紅外光譜儀分析溶液的結(jié)構(gòu)，采用微電泳儀測(cè)定Al(OH)3顆粒表面的Zeta電位。結(jié)果表明：加入適量醚類添加劑可強(qiáng)化分解過程，當(dāng)添加劑B35用量為500 mg/L時(shí)，相對(duì)空白樣可提高分解率4%；醚類添加劑B35對(duì)分解過程的強(qiáng)化不是由鋁酸鈉溶液結(jié)構(gòu)的改變引起的；添加劑B35可使Al(OH)3晶種表面Zeta電位明顯升高，說明Al(OH)3對(duì)該表面活性劑發(fā)生特性吸附，導(dǎo)致鋁酸鈉溶液在Al(OH)3顆粒表面的潤(rùn)濕角減小，其固液界面張力降低，從而使分解過程得以強(qiáng)化；此外，醚類添加劑B35使產(chǎn)品Al(OH)3平均粒徑增大10 μm左右，而粗顆粒在溶液中的平衡溶解度較小，分解過程推動(dòng)力較大，也應(yīng)是強(qiáng)化分解過程的原因之一。
關(guān)鍵字: 鋁酸鈉溶液；晶種分解；添加劑；潤(rùn)濕性
sodium aluminate solution
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effect of ethers additive B35 on the seeded precipitation of sodium aluminate solution was investigated, the structure of the sodium aluminate solution was analyzed by FTIR, the zeta potential of the solid surface of Al(OH)3 particles was measured by micro-electrophoresis. The results show that proper dosage of ethers additive can improve the seeded precipitation process of sodium aluminate solution. The precipitation rate can be raised by 4% when the B35 dosage is 500 mg/L. The change of the solution structure is due to the enhancement of seeded precipitation process by adding the additive rather than the effect of the additive itself. Zeta potential of solid surface of Al(OH)3 particles increases significantly when adding B35, the characteristic adsorption occurs between Al(OH)3 particles and the additive. This characteristic adsorption decreases the wet angle of the Al(OH)3 surface, reduces the solid-liquid interfacial tension force and ultimately intensifies the seeded precipitation process of sodium aluminate solution. In addition, there is another reason for enhancing precipitation that the equilibrium solubility of coarse particles is relatively smaller than that of the fine particles in sodium aluminate solution, and thus increases the driving force of precipitation process, and the average particle size of products increases by about 10 μm through adding ethers B35.
Key words: sodium aluminate solution; seeded precipitation; additive; wettability
