【摘要】 采用均匀沉淀法,用尿素为水解剂,60～90℃,0.005mol·L^-1≤C(La³⁺)≤0.025mol·L^-1,0.27mol·L^-1≤C（urca）≤0.81mol·L^-1,用La（NO₃）₃溶液备了La（Ⅲ）的超微粒化合物,所得沉淀为LaOHCO₃,具有与CaCO₃超微粒相似的结晶形态,粒径≤0.02μm.将此超微粒前驱体置于高温沪中,1200℃烧1h后,得到La₂O₃超微粒,粒径≤0.04μm.更多还原

【Abstract】 By means of the homogeneous precipitation and with urea as the hydrolytic agent (at 60-90 C . 0. OOSmol L-’< [La3+] initial <0. 025 mol L->, 0. 27 mol L-’< [urea] initial <0. 81 mol L-’, the La ( H ) ultrafine particle compound from La(NO3)3 solution was prepared. The precipitates obtained are LaOHCO3, whose size is less than 0. 02 Mm in diam and whose crystal pattern is similar to that of CaCOs ultrafine particales. The La2O3 ultrafine particles with the size of less than 0. 04 |am in diam. Can be obtained by means of calcining the ultrafine particle precursors at 1200 C in the high-temperature stove for an hour.更多还原