(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 研究鉻酸鈉堿性液中和除鋁方式、溫度和堿性液種類對除鋁漿液沉降性能的影響規(guī)律。結(jié)果表明：晶種中和法獲得的鋁泥前2 min平均沉降速率達(dá)107.1 mm/min，含水率小于38%，鉻帶損小于0.26%；而采用傳統(tǒng)的直接中和法獲得的鋁泥前2 min平均沉降速率小于7.25 mm/min，含水率大于67%。氫氧化鋁粒度分布、掃描電鏡和接觸角測定結(jié)果表明：提高中和除鋁的溫度、降低堿性液SiO2等雜質(zhì)含量有利于改善除鋁漿液的沉降性能。鋁泥顆粒粗、結(jié)晶好，且其表面疏水性強(qiáng)、表面能低、溶劑化趨勢小，能提高鋁泥的沉降性能。
關(guān)鍵字: 鉻酸鈉溶液；中和；除鋁；沉降性能；接觸角；表面性質(zhì)
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The influence of neutralization method, temperature and types of chromate solution on the settlement property of alumina tri-hydrate was studied in the removal of alumina from chromate solution. The results show that the average settlement rate of alumina tri-hydrate is up to 107.1 mm/min in initial 2 min, and water content and loss of chromate in alumina tri-hydrate is less than 38% and 0.26%, respectively by seeded neutralization. In contrast, the average settlement rate of alumina tri-hydrate is less than 7.25 mm/min in initial 2 min period, and water content is more than 67% by traditional direct neutralization process. In addition, increasing temperature or removing SiO2 in solution benefits the improvement of the settlement property for alumina tri-hydrate in the seeded neutralization process. Based on the measurement of the contact angle, particle size distribution and SEM, the results also indicate that the better settlement property of alumina tri-hydrate can be attributed to coarse particle, good crystallization, hydrophobic, low surface free energy and little solvent tendency of alumina tri-hydrate in the removal of alumina in chromate solution.
Key words: sodium chromate solution; neutralization; alumina removal; settlement property; contact angle; surface property
