摘要
对以NaOH为碱化剂合成的聚合氯化铝铁(PAFC)及其合成前体聚合氯化铝(PAC)、聚合氯化铁(PFC)的低温干燥胶体进行了表征。红外光谱证实PAFC中存在Fe-O-HAl基团;X射线衍射结果证实了PAFC中有着与PAC、PFC不同形态的Al(Ⅲ)、Fe(Ⅲ)羟基配合物,这些Fe-Al羟合异核多核共聚物是长程无序的;扫描电镜能谱分析表明:短程有序的Al-OH-Fe羟合物在Fe(Ⅲ)、Al(Ⅲ)继续水解的过程中与它们一起随机排列,形成长程无序的Fe-Al羟合异核多核共聚物无定形胶体。Al(Ⅲ)对Fe(Ⅲ)的保护作用包括三个方面:Al(Ⅲ)对Fe(Ⅲ)的水解有催化作用,使Fe(Ⅲ)形成更多细微的结晶中心而不是相互聚集生成较大的结晶;大量Al(Ⅲ)的存在使Fe(Ⅲ)羟合物之间的碰撞受到制约,相当于降低了Fe(Ⅲ)的有效浓度,延缓了Fe(Ⅲ)的迅速水解;大量短程有序的Al-OH-Fe羟合物的存在破坏了Al13相及-βFeOOH相的生成环境,有效地保护了Fe(Ⅲ)胶团并使它们在水溶液中的稳定时间大大增加。
The synthesized polyaluminum ferric chloride （PAFC）, polyaluminum chloride （PAC） and polyferric chloride （PFC） with NaOH as basicity agent have been characterized by FFIR, XRD, SEM and EDS. IR spectra showed that there are radicals of AI-↑（H）O-Fe in PAFC aqua solutions and they are of short-range order. But nine PAFC samples with Al/Fe tool ratios from I ： 9 to 9 ： 1 are all amorphous polymers in which there are neither phases of Al13 nor β-FeOOH. The X-ray powder diffraction results showed that there are other species of co-aggregation of Fe （ Ⅲ）-Al （Ⅲ ） hydroxyl polymers in PAFC aqua solutions and they are of long range disorder. And scanning electron mierography and energy dispersive H spectrometry data displayed that the short range order radicals of AI-↑（H）O-Fe took part in the continual hydrolysis of Al（ Ⅲ ） and Fe（ Ⅲ ） ions. As a result, there was formed long range-disorder mieelle of co-aggregation of Fe（ Ⅲ ）-Al（ Ⅲ ） hydroxyl polymers with heterogeneous nucleation. The ftmctions of improvement on Fe（ Ⅲ ） stability by Al（ Ⅲ ） including： catalysis of Al（ Ⅲ ） for Fe（ Ⅲ ） hydrolysis, which makes Fe（Ⅲ ） ions form more crystal nucleus rather than co-aggregate to form larger hydroxyl crystals. There are numerous Al（ Ⅲ ） ions in PAFC aqua solutions, which obstruct the collision of Fe（ Ⅲ ） ions each other and diminish their activity. As a result, rapid hydrolysis of Fe（ Ⅲ ） ions was put off. Large quantifies of H short range order radicals of AI-↑（H）O-Fe in PAFC aqua solutions protect and disperse Fe （ Ⅲ ） polymer and disturb the formation surrotmdings of β-FeOOH, these Fe（Ⅲ） crystal nucleus cannot grow to form Fe hydroxides or oxides, but combined with AI（Ⅲ） ions or Al（Ⅲ） hydroxyl polymers to form Fe（Ⅲ）-Al（Ⅲ） hydroxyl polymers. From the above, it can be seen that Al（Ⅲ） protects and disperses Fe（Ⅲ） polymer and improves the Fe（Ⅲ） stability
出处
《矿物学报》
CAS
CSCD
北大核心
2006年第1期47-52,共6页
Acta Mineralogica Sinica
基金
四川省重点学科资助项目(SZD0407)
