(1. 中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長沙 410083；
2. 中國鋁業(yè) 山東分公司， 淄博 255052)
摘 要: 研究磷酸改善氫氧化鋁粉體熱穩(wěn)定性的工藝及修飾處理對粉體形貌與物相的影響， 并探討磷酸提高氫氧化鋁熱穩(wěn)定性的機(jī)理。結(jié)果表明： 反應(yīng)溫度的提高、 反應(yīng)時(shí)間的延長及磷酸濃度的加大均有利于氫氧化鋁熱穩(wěn)定性的提高， 當(dāng)磷酸濃度為10%、反應(yīng)溫度與時(shí)間分別取90 ℃與75 min時(shí)， 可使氫氧化鋁中結(jié)晶水的初始失去溫度由192 ℃提高到211 ℃； 磷酸提高氫氧化鋁熱穩(wěn)定性的原因可能是磷酸與氫氧化鋁反應(yīng)所生成的耐熱鋁鹽包覆在氫氧化鋁顆粒的表面；所研究的修飾工藝沒有改變粉體的三水鋁石結(jié)構(gòu)， 但磷酸處理會(huì)使粉體顆粒長大， 并且還會(huì)有大尺寸團(tuán)聚粒子的出現(xiàn)。
關(guān)鍵字: 氫氧化鋁； 磷酸； 改性； 熱穩(wěn)定性
modified by phosphoric acid
LI Jie1, WU Shang-yuan1
（1. School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China;
2. Shandong Branch, China Aluminium Corporation, Zibo 255052, China）
Abstract: The modification technology for improving thermal stability of aluminum hydrate powder with phosphoric acid and its effects on morphology and phase of modified powder were investigated, and the improvement mechanism on thermal stability of aluminum hydrate was discussed. The results show that raising reaction temperature, prolonging reaction time and increasing concentration of phosphoric acid are favorable to improve the thermal stability of aluminum hydrate. The initial loss temperature of crystal water i, n aluminum hydrate rises from 192 ℃ to 211 ℃ at the phosphoric acid concentration of 10%, reaction temperature of 90 ℃ and reaction time of 75 min. The improvement mechanism of phosphoric acid on thermal stability of aluminum hydrate may be attributed to their interreaction which produces heat resistant aluminum salt film on the aluminum hydrate particle. The modification technology doesn't change the trihydrate alumina structure of powder, however, it will make the particles grow up and coarse granule appear.
Key words: aluminum hydrate; phosphoric acid; modification; thermal stability
