摘要
以MgCl_(2)为晶面调控剂,利用水热法对氢氧化镁(MH)的(001)晶面选择性生长进行了调控,研究了晶面调控剂浓度、反应温度、反应时间对MH颗粒的溶解和结晶作用。在MH 40 g、纯水160 mL、晶面调控剂浓度0.5 mol/L、160℃、500 r/min条件下水热处理6 h得到产品,产品各晶面的XRD衍射峰强度I001/I101和I001/I110较原料分别提高了213.95%和307.87%。百吨级中试实验控制MH固含量为10%,加入550 kg MH工业品,晶面调控剂浓度为0.5 mol/L,在160℃,150 r/min水热处理6 h,产品的I_(001)/I_(101)和I_(001)/I_(110)较原料分别提高了83.72%和112.83%。采用XRD、FE-SEM、TEM、FTIR、粒度分析仪对MH产品的形貌、结构进行了表征,并对调控机理进行了研究。结果表明,MgCl_(2)可以在水热体系中促进MH的(001)晶面选择性生长。一方面,MgCl_(2)作为强酸弱碱盐降低了体系pH,Cl^(–)可通过电荷中和效应使MH发生加速溶解;另一方面,MgCl_(2)通过提供Cl^(–)促进了MH边缘的生长,进而强化了(001)晶面的生长。
Selective controllable growth of Mg(OH)(MH)(001)crystal surface by hydrothermal method was conducted using MgCl_(2)as crystal surface regulator,and characterized by XRD,FE-SEM,TEM,FTIR,and particle size analyzer for morphology and structure analyses.The effects of crystal surface regulator concentration,reaction temperature and reaction time on the dissolution and crystallization of MH particles were then investigated,and the regulation mechanism was also explored.The product was obtained by hydrothermal treatment under the conditions of MH 40 g,160 mL of pure water,0.5 mol/L concentration of crystal surface modifier,160℃and 500 r/min for 6 h,the XRD peak intensity(I001/I101 and I001/I110)of the regulated products increased by 213.95%and 307.87%.The product I_(001)/I_(101)and I_(001)/I_(110)were 83.72%and 112.83%higher than the raw material respectively when the solid content of MH was controlled at 10%in a 100-ton pilot experiment by adding 550 kg of MH industrial product with a concentration of 0.5 mol/L of crystal surface regulator and hydrothermal treatment at 160℃and 150 r/min for 6 h.respectively,compared with the raw material in the 100-ton pilot experiment.It was also found that MgCl_(2)successfully promoted the(001)crystal face selective growth of MH in the hydrothermal system.On the one hand,MgCl_(2)as a strong acid and weak base salt lowered the pH of system,while Cl^(–)accelerated MH dissolution through charge neutralization.On the other hand,Cl^(–)provided by MgCl_(2)promoted the edge growth of MH,which in turn enhanced the(001)crystal plane growth.
作者
曹雨微
刘远
孔会民
岳萍
唐大才
林彦军
CAO Yuwei;LIU Yuan;KONG Huimin;YUE Ping;ANG Dacai;LIN Yanjun(State Key Laboratory of Chemical Resource Engineering,Bejing University of Chemical Technology,Bejing 100029,China;Technology Development of Western Mining Group Co.,Ltd.,Xining 810007,Qinghai,China;College of Chemical Engineering,Qinghai University,Xining 810016,Qinghai,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2022年第10期2035-2043,共9页
Fine Chemicals
基金
国家重点研发计划(2018YFC1903805)
青海省重大科技专项(2020-GX-A1)。
关键词
氢氧化镁
MgCl_(2)
晶面调控剂
(001)晶面
机理分析
功能材料
Mg(OH)_(2)
MgCl_(2)
crystallographic surface modulator
(001)crystalline surface
mechanism analysis
functional materials
