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前文报道了多核NMR方法研究NaCl-NH_4Cl-H_2O体系相图,表明具有不受其它离子干扰和快速、简便等优点。本文用~(23)Na、~(27)Al NMR方法研究了Na_2SO_4-Al_2(SO_4)_3-H_2O体系,指出20℃时平衡固相中有Na_2SO_4·10H_2O,Al_2(SO_4)_3·18H_O及NaAl(SO_4)_2·12H_2O等水合物和复盐存在,与其它方法所得结果吻合。实验部分分析纯Na_2SO_4于120℃干燥8小时,保存在干燥箱中备用。对分析纯Al_2(SO_4)_3·18H_2O用EDTA-Zn经典返滴方法分析,证实其组成为Al_2(SO_4)_3·18H_2O,符合NMR定量分析
The previous report of the multi-nuclear NMR method for the study of NaCl-NH_4Cl-H_2O system phase diagram shows that with other ions interference and fast, simple and so on. In this paper, the Na_2SO_4-Al_2 (SO_4) _3-H_2O system has been studied by ~ (23) Na and ~ (27) Al NMR methods. It is found that Na_2SO_4 · 10H_2O, Al_2 (SO_4) _3 · 18H_O and NaAl (SO_4) _2 · 12H_2O and other hydrates and double salts exist, and the results obtained by other methods are in good agreement. Experimental analysis of pure Na_2SO_4 dried at 120 ℃ for 8 hours, stored in a dry box for use. The analytic pure Al_2 (SO_4) _3 · 18H_2O was analyzed by EDTA-Zn classical drop-back method and confirmed to be Al_2 (SO_4) _3 · 18H_2O, which was in accordance with the quantitative analysis by NMR