基于高效解离-选择性絮凝耦合作用的煤气化渣提炭实验研究

Experimental study on carbon extraction from coal gasification slag based on coupling effect of high-efficiency dissociation-selective flocculation

煤气化渣是由煤气化工艺产生的一种富含铝硅酸盐、灰组分及残炭的大宗工业固体废弃物,其规模化生产对生态环境造成了严重的影响。因此,将煤气化渣进行炭-灰分离是实现其减量化、无害化和资源化利用的关键。以煤气化渣为研究对象,采用高效解离-选择性絮凝耦合作用的工艺,为实现煤气化渣更为合理、高效的资源化利用,减少煤气化渣带来的土壤、空气、水体资源等污染问题,对煤气化渣进行提炭实验研究。首先分析了煤气化渣的理化性质,其次采用单因素变量法探究了磨矿时间、pH、絮凝剂种类、絮凝剂用量、高速剪切转速对煤气化渣提炭实验的影响,以实现残余炭产品的高度富集。结果表明:原煤气化渣灰分质量分数为67.19%,普通湿筛筛上物料灰分质量分数为54.3%,当煤气化渣磨矿时间为5 s, pH为7,絮凝剂聚氧化乙烯用量为0.4 kg/t,在转速为4 000 r/min高速剪切15 min的条件下提炭效果最佳,最终可获得产率为26.6%、湿筛筛上灰分质量分数为43.3%的残炭产品。对比普通湿筛法,基于高效解离-选择性絮凝实验方法在普通湿筛的基础上灰分质量分数降低了11%,降灰效果明显。

Coal gasification slag generated by coal gasification process is an industrial solid waste abundant in aluminosilicates,ash components and carbon residues.Coal gasification slag has a significant negative impact on the environment due to its huge production.Hence,the separation of coal and ash from coal gasification residue is the crucial step in achieving waste reduction,mitigation of harm and resource usage.The extraction of coal from coal gasification slag is experimentally investigated utilizing a high efficiency dissociation-selective flocculation coupling process,aiming to achieve more viable and efficient utilization while mitigating pollution issues associated with soil,air,and water resources.Firstly,the physical and chemical properties of coal gasification slag were analyzed.Subsequently,the impact of variables including grinding time,pH,flocculant type,flocculant dosage,and high-speed shear speed on the carbon extraction test of coal gasification slag were investigated using a single factor variable method,with the goal of achieving high enrichment of residual carbon products.The experiment results show that the ash mass fraction of raw coal gasification slag is 67.19%,and the ash mass fraction of ordinary wet sieve is 54.3%.The optimal conditions are achieved by grinding the coal gasification slag for 5 s at a pH of 7,using a high-speed shear speed of 4000 r/min for 15 min with a dosage of 0.4 kg/t of polyoxide flocculant.The final carbon residue product with yield of 26.6%and ash mass fraction of 43.3%on wet screen are obtained,respectively.Compared to the common wet screening method,the ash mass fraction based on the high-efficiency dissociation-selective flocculation test method is reduced by 11%on the basis of the ordinary wet screening,and the ash reduction effect is obvious.