[机] bessemer converting acid proccess, bessemer converting acid process
suān xìng zhuàn lú zuò yè ㄙㄨㄢ ㄒㄧㄥˋ ㄓㄨㄢˋ ㄌㄨˊ ㄗㄨㄛˋ ㄧㄝˋ