Synthesis of Spinel Powder by the Homogeneous Precipitation Method from Inorganic Salts and Their Sintering.

无机盐均相沉淀法合成尖晶石粉及其烧结。

基本信息

批准号：
01550604
负责人：
KATO Akio
金额：
$ 1.47万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550604/
关键词：
Homogeneous precipitation method Inorganic salts Spinel Alumina Urea スピネル(MgAl_2O_4)アルミナ(Al_2O_3)

项目摘要

Spinel (MgAl_2O_4) powders were prepared by the homogeneous precipitation method from the aqueous solutions of nitrates or sulfates mixture of aluminum and magnesium using urea, and their sinterability was studied.Precipitates with spinel composition obtained from the nitrate solution consisted of Al_2O_3 gel and Mg-Al double hydroxide. From the sulfate solution. MgO hydrate deposited on Al_2O_3 hydrate particles. On heating above 800^ﾟC for 1h in air, both precipitates became spinel phase. Indicating the higher reactivity of both components in the present powders than that in the powder mixture of MgO and Al_2O_3.The powder prepared from the solution of nitrates mixture became solid coagulation on drying. When powder ground and calcined at 800^ﾟC was sintered at 1500^ﾟC for 4h, a sintered body with 95% of theoretical density was obtained. In sintering at 1600^ﾟC, the same density was obtained.On the other hand, in the powder prepared from the solution of sulfates mixture, a sintered body with 96.7% of theoretical density was obtained when the synthesized powder was calcined at 1000^ﾟC and sintered at 1500^ﾟC for 4h. A sintered body with 99.2% of theoretical density was obtained by sintering at 1600^ﾟC for 4h from the powder calcined at 800^ﾟC and ground.As a fundamental study on synthesis of spinel powder, the effect of synthesis conditions, especially the effect of additives, on the morphology of Al_2O_3 hydrate was investigated in the precipitation from aluminum salt solution by the homogeneous precipitation using urea.

【摘要】：以铝镁硝酸盐或硫酸盐混合物水溶液为原料,采用尿素均相沉淀法制备了尖晶石(MgAl_2O_4)粉末,并研究了其烧结性能。从硝酸盐溶液中得到的尖晶石沉淀物由Al_2O_3凝胶和Mg-组成。由氢氧化铝硫酸盐溶液沉积在Al_2O_3水合物上。在空气中加热到 800^ﾟC 以上 1h 时，两种沉淀物都变成尖晶石相，表明本粉末中两种组分的反应活性高于 MgO 和 Al_2O_3 的粉末混合物。由硝酸盐溶液制备的粉末。当粉末在800℃下研磨并在1500℃下烧结时，混合物在干燥时变成固体凝结物。在1600℃下烧结4小时，获得了理论密度95％的烧结体。另一方面，在由硫酸盐混合物溶液制备的粉末中，获得了96.7的烧结体。理论密度%是合成粉末在1000^ﾟC下煅烧并在1500^ﾟC下烧结时获得的将800℃煅烧并研磨的粉末在1600℃烧结4h，得到理论密度99.2%的烧结体。作为尖晶石粉末合成的基础研究，研究了合成条件的影响。通过尿素均匀沉淀法从铝盐溶液中沉淀，研究了Al_2O_3水合物形貌的影响，特别是添加剂对Al_2O_3水合物形貌的影响。