Kuchiza madzi oipa omwe ali ndi chromium mu electroplating

Kuyerekeza zotsatira za mankhwala a ferrous sulfate ndi sodium bisulfite

Njira yopangira ma electroplating imayenera kupangidwa ndi malata, ndipo poyeretsa malata, makamaka chomera chopangira ma electroplating chidzagwiritsa ntchito chromate, kotero kuti madzi owonongeka a electroplating atulutsa madzi ambiri onyansa okhala ndi chromium chifukwa cha plating ya chromium.Chromium yomwe ili m'madzi oipa omwe ali ndi chromium imakhala ndi hexavalent chromium, yomwe ndi yapoizoni komanso yovuta kuchotsa.Hexavalent chromium nthawi zambiri imasinthidwa kukhala trivalent chromium ndikuchotsedwa.Pochotsa madzi otayira okhala ndi chrome okhala ndi ma electroplating, ma coagulation ndi mpweya amagwiritsidwa ntchito nthawi zambiri kuti achotse.Nthawi zambiri amagwiritsidwa ntchito ndi ferrous sulfate ndi njira yochepetsera laimu komanso sodium bisulfite ndi njira yochepetsera mpweya wa alkali.

1. ferrous sulfate ndi njira yochepetsera laimu

Ferrous sulfate ndi amphamvu asidi coagulant ndi amphamvu oxidation-kuchepetsa katundu.Ferrous sulfate imatha kuchepetsedwa mwachindunji ndi hexavalent chromium pambuyo pa hydrolysis m'madzi otayirira, ndikuisintha kukhala gawo la trivalent chromium coagulation ndi mpweya, kenako ndikuwonjezera laimu kuti musinthe pH yamtengo wa 8 ~ 9, kuti ithandizire kugundana kwamadzi. kupanga mpweya wa chromium hydroxide, kuchotsedwa kwa chromate kumatha kufika pafupifupi 94%.

Ferrous sulfate kuphatikiza laimu coagulant kuchepetsa mpweya wa chromate kumakhala ndi zotsatira zabwino pakuchotsa chromium komanso kutsika mtengo.Kachiwiri, palibe chifukwa chosinthira pH mtengo musanayambe kuwonjezera ferrous sulfate, ndipo muyenera kuwonjezera laimu kuti musinthe pH mtengo.Komabe, chifukwa cha kuchuluka kwa ferrous sulfate dosing adayambitsanso kuwonjezereka kwakukulu kwamatope achitsulo, kuonjezera mtengo wa mankhwala a sludge.

2,.sodium bisulfite ndi njira yochepetsera mpweya wa alkali

Sodium bisulfite ndi alkali reduction precipitation chromate, pH ya madzi oipa imasinthidwa kukhala ≤2.0.Kenako sodium bisulfite imawonjezedwa kuti ichepetse chromate kukhala trivalent chromium, ndipo madzi otayira amalowa mu dziwe lathunthu atamaliza kutsitsa, madzi otayira amapoperedwa ku dziwe lowongolera kuti asinthe, ndipo pH mtengo umasinthidwa kukhala pafupifupi 10 powonjezera alkali. nodes, ndiyeno madzi otayira amatayidwa ku thanki ya sedimentation kuti apangitse chromate, ndipo kuchuluka kwa kuchotsa kumatha kufika pafupifupi 95%.

Njira ya sodium bisulfite ndi alkali kuchepetsa mpweya chromate ndi yabwino kuchotsa chromium, ndipo mtengo wake ndi wokwera kwambiri kuposa ferrous sulfate, ndipo nthawi yochitira mankhwala ndi yotalikirapo, ndipo pH mtengo uyenera kusinthidwa ndi asidi musanalandire chithandizo.Komabe, poyerekezera ndi mankhwala a ferrous sulfate, kwenikweni satulutsa zinyalala zambiri, zomwe zimachepetsa kwambiri mtengo wothira zinyalala, ndipo matope oyeretsedwa amatha kugwiritsidwanso ntchito.