Pilot-scale Study On Produce To Electromagnetic Shielding With Coal Tar Pitch And Lignin From Paper-making Black Liquor

In this pilot-scale study, lignin from black liquor of papermaking and medium pitch which used as the raw materials were carbonized to produce electromagnetic shielding material after loading nickel and calcium. The crystal structure of chars was checked with XRD and SEM. Lignin was obtained from black liquor of papermaking by two step process (sulphur dioxide, silica removal), which was analyzed by FT-IR,TG. Then lignin was carbonized by loading various amounts of nickel and calcium. The results revealed that, optimal condition were Ni8wt%, Ca6wt%, 900℃ carbonisation temperature in the pilot-scale study. The coal tar pitch was separated into two fractions (THF-insoluble, THFI; THF-soluble, THFS) by solvent exaction using tatrahydrofuran (THF). The coal tar pitch (CTP) and its two fractions ( THFI and THFS) were carbonized, which reveals that The effects of THFI, carbonization temperature, the amount of nickel, and the type and amount of calcium on the crystallite sizes (Lc) of various chars with nickel and calcium loading. The results showed that Lc for the chars with 1.6wt% calcium increased with increasing amount of nickel loaded; Lc for the chars with an equal loading of 7wt% nickel increased with increasing amount of calcium added and then decreased and that, with an equal co-loading of 7 wt% nickel and 1.6 wt% calcium, also increased with increasing carbonisation temperature, from 700 to 900 ℃. The present study demonstrated that the EMS capacities exceeded a practical standard of EMS capacities when Lc of chars exceeded 60 ?, so the EMS materials with excellent EMS capacities would be obtained.