Possibilities of carbon black recovery from waste tyre pyrolysis to be used as additive in rubber goods -a review-

This work deals with the literature review of the main carbon black (CB) properties required for reinforcing-filler rubber applications. Commercial CB is rich-carbon material widely used as reinforcing filler in rubber goods. When waste tyres are transformed by pyrolysis, the obtained solid fraction known as pyrolytic carbon black (CBp) contains the original CB (80-90 wt.%) added in tyre manufacturing process along with sulphur (1-3 wt.%) and a representative quantity of inorganics (10-15 wt.%). Taking this into account, it could be inferred that some physical-chemical properties of CBp are similar to those of the original CB. This fact has encouraged the use of CBp as an alternative substitute of CB in different rubber applications. However, it has been found that CBp can be used in certain rubber applications, some research works have also noted the detrimental of some mechanical properties. The inorganics presence in CBp limits some important properties such as tensile strength, tear strength, and hardness in the rubber composites. Also, these compounds as well as some carbonaceous deposits seem to affect the surface area and the surface chemistry, and therefore the active sites, affecting the reinforcing activity. To overcome these limitations, some post-treatments processes are proposed.