Quality Improvement of Pyrolysis Char Derived From Various Kind of Solid Waste for Recycling

本研究以工业废渣等16种不同来源的焦炭为原料进行了实验研究。为了使用焦炭作为燃料，应降低氯气含量以避免腐蚀。从溶解度的角度对垃圾焦中的氯进行了表征。CO2鼓泡可将氯气降至水泥窑使用时可接受的水平。粉化对非水溶氯的溶解是无效的。灰分是另一种需要降低的焦炭燃料。富灰馏分(r&lt；125um)经过浮沉分离、泡沫浮选和油凝聚等方法处理。结果表明，焦炭的可燃回收率较低，焦炭质量较好，热值较高。对于垃圾焦炭，采用泡沫浮选或油凝聚的方法可以达到目标质量水平(热值20000 kJ/kg，灰分30%)。EDX/SEM分析结果表明，即使经过1h的粉碎，半焦颗粒也没有分离成单一物质。即使在半焦质量不足以用作燃料的情况下，碳化也被认为是填埋前的一种热预处理方法。在间歇和柱状淋洗试验中，碳化处理均能较好地降低土壤中的可溶性有机碳含量。焦化残渣中重金属的释放量有所减少，但其程度随好氧/厌氧条件的不同而不同，这取决于焦化残渣表面或孔结构的物理吸附。

In this study, sixteen kinds of char obtained from various sources including industrial waste were used for experiments. In order to use char as fuel, chlorine level should be reduced to avoid corrosion. Chlorine in char derived from MSW was characterized in terms of solubility. CO2 bubbling could reduce chorine to acceptable level for cement kiln use. Pulverization was proven to be ineffective in the dissolution of non water-soluble chlorine.Ash content is another fraction which should be lowered for fuel use of char. Ash rich fraction (r<125 um) was subjected to float-sink separation, froth flotation, and oil agglomeration methods. As a result, a lower combustible recovery rate was resulted to get a good quality of char with high heating values. For MSW-derived char, the targeted quality level (20000 kJ/kg heating value and 30% ash content) was attained using froth floatation or oil agglomeration. Results of the EDX/SEM analysis indicated that char particles were not segregated to single substances even after being milled for 1 h.Even in the case that char quality is not good enough for fuel use, carbonization was considered as a thermal pretreatment method before landfilling. Soluble organic carbon levels were fairly decreased by carbonization both in batch and column leaching tests. The release amount of heavy metals from carbonization residue decreased but its extent could be varied with the aerobic/or anaerobic condition, and which relys on the physical adsorption onto the surface or pore structure of carbonization residue.