Niaj Hnub Nimno qhuav tshuab

Lub tshuab ziab khaub ncaws ruaj khov nrog lub sijhawm ua haujlwm sib luag tau siv thaum pib. Nyob nruab nrab ntawm xyoo pua puv 19, kev siv lub tshuab ziab khaub ncaws ua cim rau kev txhim kho lub tshuab ziab khaub ncaws los ntawm kev ua haujlwm tsis tu ncua mus rau kev ua haujlwm tsis tu ncua. Lub nruas teb tshuab ziab khaub ncaws tuaj yeem thab cov khoom siv granule thiab txhim kho kev ziab thiab muaj zog. Qee qhov kev lag luam tau tsim kho lawv tus kheej tas mus li lub tshuab ziab khaub ncaws kom ua tau raws li qhov yuav tsum tau ua hauv kev lag luam, xws li textile thiab paper industry nruas lub tshuab ziab khaub ncaws.