Kev Zoo Sib Xws: Cov chaw tsim khoom ua tib zoo tswj cov txheej txheem calcination kom ntseeg tau tias cov khoom kawg zoo sib xws. Qhov kev sib xws no tso cai rau cov neeg siv kom vam khom cov khoom ntawm calcined petroleum coke rau lawv cov kev siv tshwj xeeb.
