Umshini Wokuxuba I-Double Shaft usetshenziselwa ukugaya izinto zokusetshenziswa zezitini nokuxutshwa namanzi ukuze uthole izinto ezixubile ezifanayo, ezingase zithuthukise ukusebenza kwezinto ezingavuthiwe futhi zithuthukise kakhulu ukubukeka nezinga lokubumba lezitini.Lo mkhiqizo ulungele ubumba, i-shale, i-ganggue, i-fly ash nezinye izinto zokusebenza ezibanzi.