3. Results and discussion
All the fractions of the WPCB were separated and recovered
through vacuum pyrolysis and mechanical processing. And the
recycled products were respectively oils, copper and glass fiber.
Schematic illustration of recycling WPCB was shown in Fig. 4.
3.1. Vacuum pyrolysis
The aim of vacuum pyrolysis was to separate and recover the
organics from the WPCB without negative impact to the environment.
The weight percentage of residues, oils and gases obtained
in the WPCB vacuum pyrolysis experiments was 74.7%, 15.0% and
10.3%, respectively. The main composition of pyrolysis products
were presented in Table 2.
3.1.1. Pyrolysis residues
The pyrolysis residues obtained by vacuum pyrolysis was shown
in Fig. 4. The pyrolysis residues mainly consisted of glass fiber, copper
and carbon. And the composition of the pyrolysis residues was
presented in Table 2.
It could been seen from Fig. 4 that the residues obtained in the
WPCB vacuum pyrolysis experiments was composed of pieces of
equal dimensions to those of the original ones, and the color of
WPCB after pyrolysis was changed to completely black, which was
coke like carbonaceous product formed during the process due to
cyclization and secondary repolymerization reactions [27,28]. Furthermore,
the delamination between copper and other components
appeared due to the results of complex physicochemical changes
taking place in different material components during the vacuum
pyrolysis processing [31]. From theXRDanalysis of residues (Fig. 5),
only SiO2 and Cu were detected in the residues. However, copper
oxides were not detected by XRD which may be attributed to the
minor content of copper oxides. As the pyrolysis experiments were
carried out under vacuum during the vacuum pyrolysis processing,
little copper in the residue was oxidized to copper oxides. The copper was indicated to be simple substance of copper with high purity.
3. Results and discussion
All the fractions of the WPCB were separated and recovered
through vacuum pyrolysis and mechanical processing. And the
recycled products were respectively oils, copper and glass fiber.
Schematic illustration of recycling WPCB was shown in Fig. 4.
3.1. Vacuum pyrolysis
The aim of vacuum pyrolysis was to separate and recover the
organics from the WPCB without negative impact to the environment.
The weight percentage of residues, oils and gases obtained
in the WPCB vacuum pyrolysis experiments was 74.7%, 15.0% and
10.3%, respectively. The main composition of pyrolysis products
were presented in Table 2.
3.1.1. Pyrolysis residues
The pyrolysis residues obtained by vacuum pyrolysis was shown
in Fig. 4. The pyrolysis residues mainly consisted of glass fiber, copper
and carbon. And the composition of the pyrolysis residues was
presented in Table 2.
It could been seen from Fig. 4 that the residues obtained in the
WPCB vacuum pyrolysis experiments was composed of pieces of
equal dimensions to those of the original ones, and the color of
WPCB after pyrolysis was changed to completely black, which was
coke like carbonaceous product formed during the process due to
cyclization and secondary repolymerization reactions [27,28]. Furthermore,
the delamination between copper and other components
appeared due to the results of complex physicochemical changes
taking place in different material components during the vacuum
pyrolysis processing [31]. From theXRDanalysis of residues (Fig. 5),
only SiO2 and Cu were detected in the residues. However, copper
oxides were not detected by XRD which may be attributed to the
minor content of copper oxides. As the pyrolysis experiments were
carried out under vacuum during the vacuum pyrolysis processing,
little copper in the residue was oxidized to copper oxides. The copper was indicated to be simple substance of copper with high purity.
การแปล กรุณารอสักครู่..
