摘要
依据铝酸钠溶液碳酸化分解遵循晶种分解的机理,在自制碳分槽中采用间断碳分的方法,在不添加Al(OH)3晶种的条件下,研究了不同分解工艺条件[分解温度70～95℃,CO2气体浓度25%～60%(φ),CO2通气速度0.055～0.167m3/(h·L)]对高浓度铝酸钠溶液碳酸化分解产品Al(OH)3中Na2O含量的影响规律.结果表明,通过提高碳酸化分解温度、降低CO2通气量来调控铝酸钠溶液的过饱和度,控制碳酸化分解速率,能显著降低分解产品中Na2O的含量.当碳酸化分解原液Al2O3浓度在170～180g/L、溶液苛性分子比αk=1.40～1.50时,控制碳酸化分解温度为95℃左右,采用低浓度、慢速通气制度,分解6h左右分解率达到90%～93%,所得碳酸化分解产品中Na2O含量可控制在0.25%(ω)以下.
According to the mechanism of carbonization of sodium aluminate solution following the mechanism of seeded precipitation, the influences of different conditions, temperature 70-95 ℃, CO2 concentration 25%-60%（φ）, and CO2 ventilation rate 0.055-0.167 m^3/（h·L）, for batch carbonization of sodium aluminate solution with high alumina concentration on Na2O content in carbonization product were investigated in the self-designed carbonization tank without addition of ahtminum hydroxide seed. The results show that Na2O content in carbonization product can be significantly reduced by increasing carbonization temperature and decreasing the amount of ventilated CO2 to adjust the super-saturation of liquor and control the carbonization rate of sodium aluminate solution. Na2O content in carbonization product could reach less than 0.25%（ω） with low CO2 concentration and ventilation rate under the following carbonization conditions： carbonization temperature is in the vicinity of 95℃, alumina concentration in the original purified aluminate solution for carbonization varies from 170 to 180 g/L with molar ratio of Na2O to alumina 1.40-1.50, and carbonization time is about 6 h with carbonization rate 90%-93%.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2008年第5期945-948,共4页
The Chinese Journal of Process Engineering
基金
国家重点基础研究发展规划(973)基金资助项目(编号:2005CB6237-02)
关键词
高浓度
铝酸钠溶液
碳酸化分解
NA2O
high concentration
sodium aluminate solution
carbonization precipitation
Na2O
