Phenolic resin type waste PCB (wPCB) is one of the most important kinds of waste electrical and electronic equipment (WEEE) in China.It is usually hard to recycle for its high content of brominated flame retardants

so the key of recycling the wPCB is to debrominate

i.e.

to convert the organic bromides into inorganic ones

e.g.

hydrogen bromide (HBr).Hence

pyrolytic debromination experiments were conducted to reveal the effect of blending calcium carbonate (CaCO3) with the wPCB in pyrolysis.The results of thermogravimetric analysis indicated that CaCO3 could absorb HBr to restrain them from reacting with organic molecules when the wPCB was blended with CaCO3 powders in pyrolysis.Further

a pyrolysis experiment blending the wPCB with CaCO3 in a quartz glass tube reactor was performed by means of silver nitrate titration to determine the content of inorganic bromides.The results showed that 93.4% inorganic bromides were trapped when the wPCB and CaCO3 blended in the same quantity

and two times of inorganic bromides than without blending CaCO3 were produced.Moreover

when the wPCB was pyrolyzed with CaCO3

the contents of organic bromides in the pyrolysates

measured by GC/MS

were 25% less than those when just wPCB was pyrolyzed.It proved that the CaCO3 helped to debrominate in the pyrolysis of the wPCB.