摘要：

采用诱导结晶法软化煤制甲醇气化灰水，研究了不同诱导晶种（石榴石、方解石、石英砂等）及其加入量（2.5、4.0、5.0、6.0、7.5 g/L）、pH、药剂NaAlO₂、搅拌速度（100、200、300、400、500 r/min）对煤制甲醇气化灰水软化效果的影响。结果表明，使用石榴石作为诱导晶种，在pH 11、石榴石和NaAlO₂投加量为6.0 g/L和0.1 g/L、搅拌速度300 r/min、结晶时间1 h下，总硬度由670 mg/L降至19 mg/L，去除率达到97.16%，全硅（以SiO₂计）由180 mg/L降至24 mg/L，去除率达到86.67%。通过SEM-EDS表征发现，石榴石表面负载了CaCO₃、Mg（OH）₂及硅铝酸盐结晶，证实通过提供异相成核位点，有效实现了对煤气化灰水中钙镁离子、硅的去除。

关键词: 诱导结晶, 硬度, 石榴石, 软化, 气化灰水

Abstract:

The induced crystallization method was employed to soften coal-to-methanol gasification scrubber wastewater. This study investigated the effects of different seed crystals (garnet, calcite, quartz sand), their dosages (2.5, 4.0, 5.0, 6.0, 7.5 g/L), pH, NaAlO₂, and stirring speed (100, 200, 300, 400, 500 r/min) on softening efficiency. The results showed that when garnet as seed crystal under optimal conditions (pH 11, garnet dosage 6 g/L, NaAlO₂ 0.1 g/L, stirring speed 300 r/min, and crystallization time 1 h), the total hardness decreased from 670 mg/L to 19 mg/L (97.16% removal), and the total silicon (as SiO₂) decreased from 180 mg/L to 24 mg/L (86.67% removal). SEM-EDS analysis confirmed the deposition of CaCO₃, Mg(OH)₂, and silicate aluminosilicate crystals on garnet surface, demonstrating its effectiveness in removing calcium, magnesium ions, and silicon through provising heterogeneous nucleation sites.

Key words: induced crystallization, hardness, garnet, soften, gasification scrubber wastewater

中图分类号: 

• X703

• X773