Peb muaj ntau yam khoom siv dhia dej, suav nrog cov qauv thiab hom tiav, tsim nyog rau cov khoom siv khawb av txij li 0.8 txog 100 tons.
Cov khoom siv cov thev naus laus zis ua tiav zoo tshaj plaws thiab cov txheej txheem kho cua sov tshwj xeeb, ua rau nws tsis yooj yim hnav thiab siv tau ntev.