碳分母液高浓度蒸发技术的研究与应用

A study on evaporation technology for high concentrated spent carbonated liquor

本文根据实验室试验,回归出了蒸发料浆全碱浓度与结晶量的关系;分析了溶液温度、化学成份及晶种对碳分母液中碳酸钠溶解度及碳酸钠析出结晶状态的影响;提出了“添加晶种、蒸发析盐、沉降分离、固液并送”的高浓度蒸发方案。在工业试验中,通过摸索一、二级蒸发器溶液温差,调整种子的加入量和加入位置,应用高效闪蒸器降低出料温度,使结晶量达到80g/l以上,使蒸发浆液浓度全碱在270g/l以上,并最大限度减少蒸发器结疤,蒸发效率和运转周期无明显下降。

Based on experimental researches,the relations between the total alkali concen-tration and the quantity of crystalline in spent carbonated liquor is derived.The effects of the liquor temperature and chemical composition on the solubility and crystalline forms of sodium carbonate in the spent carbonated liquor are analyzed.As a result,alternative evaporation tech-nology for high concentrated spent carbonated liquor is developed with measures of the addi-tion of seed particles,precipitating sodium carbonate in course of evaporation,separation of precipitates by settling,and outlet charge of mixed precipitates /liquor.With the above-said new evaporation technology,a quantity of crystalline over80g /l and a total alkalinity of over270g/l in the liquor can be attained with minimized scale formed in the evaporators,under the condi-tions of using high efficient flash evaporators to reduce the temperature of the outlet charge and adjusting the feeding quantity of seed particles at an appropriate position in an industrial test,etc.However,the evaporation efficiency and operational cycle have not been considerably improved.