Cov txheej txheem ua kom dawb huv ECF tsis muaj chlorine rau cov ntaub xyoob

Peb muaj keeb kwm ntev ntawm kev ua ntawv xyoob hauv Suav teb. Cov qauv ntawm xyoob fiber thiab cov tshuaj lom neeg muaj pes tsawg leeg yog qhov tshwj xeeb. Qhov nruab nrab ntev ntawm cov fiber yog ntev, thiab cov qauv ntawm phab ntsa fiber yog qhov tshwj xeeb. Kev ua tau zoo ntawm kev txhim kho lub zog thaum lub sijhawm pulping yog qhov zoo, muab cov khoom siv kho qhov muag zoo ntawm cov khoom siv bleached ntawm opacity siab thiab cov coefficient scattering lub teeb. Cov ntsiab lus lignin ntawm cov khoom siv raw xyoob (kwv yees li 23% -32%) yog siab, uas txiav txim siab qhov ntau alkali thiab qib sulfidation thaum lub sijhawm pulping thiab ua noj (qhov degree sulfidation feem ntau yog 20% ​​-25%), uas ze rau ntoo coniferous. Cov ntsiab lus hemicellulose thiab silicon siab ntawm cov khoom siv raw kuj coj qee qhov teeb meem rau kev ua haujlwm ib txwm ntawm kev ntxuav pulp thiab cov kua dub evaporation thiab cov khoom siv concentration. Txawm li cas los xij, cov khoom siv raw xyoob tseem yog cov khoom siv raw zoo rau kev ua ntawv.

Cov txheej txheem bleaching ntawm cov nroj tsuag loj thiab nruab nrab ntawm xyoob tshuaj pulping yuav siv cov txheej txheem bleaching TCF lossis ECF. Feem ntau, ua ke nrog kev sib sib zog nqus thiab kev sib sib zog nqus oxygen ntawm pulping, TCF lossis ECF bleaching technology siv. Nyob ntawm tus naj npawb ntawm cov theem bleaching, xyoob pulp tuaj yeem bleached mus rau 88% -90% ci.

Peb cov ntaub so ntswg xyoob uas tau bleached tag nrho yog bleached nrog ECF (elemental chlorine free), uas muaj tsawg dua bleaching poob ntawm xyoob pulp thiab siab dua pulp viscosity, feem ntau ncav cuag ntau dua 800ml / g. ECF bleached xyoob cov ntaub so ntswg muaj cov pulp zoo dua, siv cov tshuaj tsawg dua, thiab muaj kev ua haujlwm bleaching siab. Tib lub sijhawm, lub kaw lus khoom siv tau laus thiab kev ua haujlwm ruaj khov.

Cov kauj ruam ntawm ECF cov tshuaj dawb uas tsis muaj chlorine ntawm cov ntaub xyoob yog: ua ntej, oxygen (02) raug coj mus rau hauv lub pej thuam oxidation rau oxidative delignification, thiab tom qab ntawd D0 bleaching-washing-Eop extraction-washing-D1 bleaching-washing raug ua tiav raws li qhov sib law liag tom qab ntxuav. Cov tshuaj dawb tseem ceeb yog CI02 (chlorine dioxide), NaOH (sodium hydroxide), H202 (hydrogen peroxide), thiab lwm yam. Thaum kawg, cov pulp bleached yog tsim los ntawm kev ua kom qhuav siab. Qhov dawb ntawm cov ntaub xyoob bleached pulp tuaj yeem ncav cuag ntau dua 80%.