Imveliso ye-aluminium sulfate-izinto ezikrwada, i-aluminium trihydrate

I-aluminium sulfate (Al2(SO4)3), edla ngokubizwa ngokuba yi-alum, iveliswa njengeekristale ezimhlophe ezingatshiyo nezinyibilikayo emanzini. Le hydrate eyomileyo (Al2(SO4)3.14H2O) yi-17% Al2O3 kwaye ikwathengiswa njengesisombululo se-aluminium sulfate esingu-47% w/w esiyi-8% Al2O3. Ikwathengiswa ikwimo eqinileyo njengeqhekeza, igutyungelwe phantsi okanye ithuli.

I-aluminium sulfate, i-Al2(SO4)3, isetyenziswa kakhulu kushishino. Ezona zicelo zayo zixhaphakileyo zikwishishini le-pulp nephepha kunye nokucocwa kwamanzi. I-aluminium sulfate isetyenziswa ngabantu ukususela ngo-2000 BC, xa amaYiputa ayesebenzisa i-mineral alum njenge-mordant ekudayini. Isetyenziswe ixesha elide kubungakanani bephepha ukuphucula ukuqina kunye nokwamkelwa kwe-inki kunye nokunyanga amanzi ukucacisa amanzi. Ezinye iindlela ezisetyenziswa ngayo i-alum ziquka unyango lwamanzi amdaka, njenge-arhente yokuthintela amanzi kunye ne-accelerator kwikhonkrithi, njenge-clarifier yamafutha kunye neeoyile kunye ne-arhente yokukhupha amagwebu kwiifoam zomlilo.

I-Alum (njengoko ibizwa njalo i-aluminium sulfate) yenziwe ngendlela elula enamanyathelo amabini ukusuka kwi-aluminium trihydrate kunye ne-sulfuric acid ngokwendlela elandelayo yokusabela:

2Al(OH)3 + 3H2SO4 + 8H2O → Al2(SO4)3 .14H2O ∆fH = -156 kJ mol-1

Inyathelo lokuqala libandakanya ukuxuba izithako kwi-reactor, kwaye elesibini yinkqubo yokutyumza izinto ukuze kwenziwe iintlobo ezahlukeneyo ze-alum eqinileyo ethengiswayo.

Iimpahla ezingekasilwa

I-aluminium trihydrate icocwa nge-bauxite. Iidiphozithi ze-bauxite zorhwebo (30-75% Al2O3) zenzeka e-Australia, eJamaica, eFrance, eGuyana, eGuinea, e-USA naseBrazil. I-Bauxite ore inyibilikiswa kwi-caustic soda enamandla ukuze yenze i-sodium aluminate. I-aluminium trihydrate emva koko ibangelwa yi-neutralization (ngesiqhelo nge-carbon dioxide) okanye yi-autoprecipitation (inkqubo yeBayer). Enye into eluhlaza, i-sulfuric acid, yenzelwe ukuvelisa i-superphosphate kwiFarmers Fertiliser Ltd. I-asidi ifika nge-road tanker kwaye ipompelwe kwiitanki zokugcina.