HPF法焦化脱硫废液中硫氰酸铵去除研究

Study on Removal of Ammonium Thiocyanate from HPF Coking Desulfurization Waste Liquid

HPF法焦化脱硫废液含有大量硫氰酸铵、硫代硫酸铵和硫酸铵,对其进行提盐所得硫氰酸铵等产品盐存在纯度不高、市场容量有限、产品大量堆积等问题。采用硫酸溶液去除脱硫废液中硫氰酸铵,并将其转化为硫酸铵,可在实现脱硫废液有效处理的同时回收硫酸铵。本文针对硫酸溶液去除硫氰酸铵反应,考察了反应过程中硫酸浓度、反应温度对硫氰酸铵去除率的影响,利用X射线光电子能谱技术对反应产物的晶型和组成成分进行了分析,并对实际焦化脱硫废液的处理效果进行了研究。结果表明:随着反应温度的升高和硫酸浓度的增大,硫氰酸铵去除率逐渐增大。反应温度为100℃,硫酸浓度为50%时,反应0.5min就可实现硫氰酸铵的100%去除,反应后产物为硫酸铵。此外,使用硫酸溶液可有效去除焦化脱硫废液中硫氰酸铵,实现脱硫废液的资源化利用。在反应温度100℃、硫酸质量分数为50%下,反应20min时脱硫废液中硫氰酸铵去除率达到97.9%。

HPF coking desulfurization waste liquid contains a lot of ammonium thiocyanate,ammonium thiosulfate and ammonium sulfate.The purity of ammonium thiocyanate and other product salts obtained from HPF coking desulfurization waste liquid by salt extraction technology exists purity not high enough,limited market capacity and a large amount of accumulation of ammonium thiocyanate and other product salts,etc.problems.Sulfuric acid was selected to remove ammonium thiocyanate in desulfurization waste liquid and convert it into ammonium sulfate,which can implement effective treatment of coking desulfurization waste liquid and recovery of ammonium sulfate at the same time.In this paper,the effects of reaction temperature and sulfuric acid concentration on the removal rate of ammonium thiocyanate were investigated,and the crystal form and composition of the reaction products were analyzed by X-ray photoelectron spectroscopy.Furthermore,the treatment effect of actual coking desulfurization waste liquid treated by sulfuric acid was studied.The results showed that the removal rate of ammonium thiocyanate increased gradually with the increase of reaction temperature and sulfuric acid concentration.When the concentration of sulfuric acid was 50% and the reaction temperature was 100℃,100% removal of ammonium thiocyanate was achieved in 0.5 min,and the reaction product was proved to be ammonium sulfate.In addition,the use of sulfuric acid solution could effectively remove ammonium thiocyanate in coking desulfurization waste liquid and realize the resource utilization of desulfurization waste liquid.When the mass of sulfuric acid was 50% and the reaction temperature was 100℃,97.9% of ammonium thiocyanate in coking desulfurization waste liquid was removed in 20 min.