Process Safety and Environmental Protection, Vol.84, No.B4, 309-312, 2006
Synthesis of hydroxyapatite with the mechanochemical treatment products of PVC and CaO
Polyvinyl chloride (PVC) is one of the most excellent plastic materials because of its chemical stability. It is widely used in many fields. Burning PVC generates HCl gas which must be treated properly. We have developed a non-thermal process for dechlorinating of PVC, and this process is composed of two steps: The first step is to grind the PVC waste with an active grinding additive such as CaO, leading to transformation of organic chlorine into water soluble chloride mechanochemically. The second step is to remove the formed chloride from the milled product by washing with water. The solid residue after filtration has been already dechlorinated, so that it can be recycled safely as fuel. When the filtrate is mixed with solution which contains phosphate ion PO42-, hydroxyapatite (HAp) fine particles formed. It is known that the precipitate (HAp) formed has a sorption ability for heavy metals such as Pb2+.