Effect of citric acid and 1,2-dihydroxybenzene 3,5-disulfonic acid on crystallization of calcium sulfate dihydrate under simulated conditions of phosphoric acid production

被引：19

作者：

Rashad, MM ^{[1
]}

Mahmoud, MHH ^{[1
]}

Ibrahim, IA ^{[1
]}

Abdel-Aal, EA ^{[1
]}

机构：

[1] Cent Met R&D Inst, Cairo, Egypt

来源：

CRYSTAL RESEARCH AND TECHNOLOGY | 2005年 / 40卷 / 08期

关键词：

gypsum; crystallization; phosphoric acid; induction time; citric acid; DHBDSA;

D O I：

10.1002/crat.200410422

中图分类号：

O7 [晶体学];

学科分类号：

0702 ; 070205 ; 0703 ; 080501 ;

摘要：

The effect of citric acid and 1,2-dihydroxybenzene 3,5-disulfonic acid (DHBDSA), as additives, on the crystallization of gypsum was studied under simulated conditions of the of phosphoric acid production. Calcium hydrogen phosphate and sulfuric acid were mixed with dilute phosphoric acid at 80 degrees C, and the turbidity of the reaction mixture was measured at different time periods to calculate the induction time of gypsum crystals formation. Addition of citric acid increased the induction time and decreased the growth efficiency while addition of DHBDSA decreased the induction time and increased the growth efficiency compared with in absence of additives. The crystals mean and median diameters were found to decrease in the presence of citric acid and increased in the presence of DHBDSA. The surface energy decreased with citric acid and increased with DHBDSA compared to the baseline (without additives). Interestingly, the majority of the formed crystals are tabular with DHBDSA and needle-like type with citric acid and baseline. (c) 2005 WILEY-NCH Verlag GmbH & Co. KGaA, Weinheim.

引用

页码：741 / 747

页数：7

共 22 条

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