稻壳制备含结晶水偏硅酸钠新工艺研究  

New technology for preparation of sodium metasilicate with crystal water from rice husk

作　　者：郑典模[1] 陈优霞[1] 熊智瑛[1] 姜巍[1] 

机构地区：[1]南昌大学环境与化学工程学院,江西南昌330031

出　　处：《无机盐工业》2009年第12期49-52,共4页Inorganic Chemicals Industry

摘　　要：以稻壳为原料,经过预处理、燃烧回收热能、溶出反应、生成反应、结晶等工艺过程,可制得符合HG/T 2568—2008工业偏硅酸钠的五水及九水偏硅酸钠。考察了稻壳的燃烧温度、氢氧化钠用量、溶出反应时间、反应起始温度、结晶降温方式、晶种及表面活性剂等因素的影响,确定了适宜的反应条件：稻壳燃烧温度为600℃,稻壳灰与氢氧化钠反应时间为4 h,程序降温时间为7 h,晶种加入质量分数为1%,表面活性剂加入质量分数为0.1%~0.3%。在此条件下,制得的五水偏硅酸钠总碱量（氧化钠质量分数）为28.4%,二氧化硅质量分数为28.8%,白度为74.1%,熔点为72℃;九水偏硅酸钠总碱量为21.4%,二氧化硅质量分数为20.5%,白度为96.4%,熔点为51℃。Sodium metasilicate pentahydrate and sodium metasilicate nonahydrate, which meet the standard HG/T 2568-2008 ,were synthesized with rice husk as raw material. This technological process contains the pretreatment, energy recovery by the combustion, dissolution reaction ,formation reaction, crystallization and so on. Effects of reaction factors ,such as combustion temperature of rice husk, amount of sodium hydroxide, dissolution reaction time, starting reaction temperature, modes of cooling crystallization, seed crystal, and surfactant, were investigated and optimum conditions were confirmed as follows ： combustion temperature of rice husk was 600℃, reaction time of rice husk ash with sodium hydroxide was 4 h, prograss cooling time was 7 h, and mass fractions of adding the seed crystal and the surfactant were 1% and 0.1% - 0.3 %, respetively. Under the optimum conditions, composing of sodium metasilicate pentahydrate prepared by this method was as follows：mass fraction of Na20 and SiO2 were 28.4% and 28.8% respectively,white content was 74.1% ,and melting point was 72 ℃while the composing of sodium metasilicate nonahydrate was：mass fraction of Na20 and SiO2 were 21.4% and 20.5% respectively,white content was 96.4% ,and melting point was 51℃.

关 键 词：稻壳 五水偏硅酸钠 九水偏硅酸钠 

分 类 号：TQ131.12[化学工程—无机化工]