Gypsum belongs rau lub monoclinic siv lead ua system nrog ib tug high degree ntawm cleavage thiab yog ib qho yooj yim rau tawg mus rau hauv nyias slices. Hemihydrate gypsum tuaj yeem tau los ntawm cua sov gypsum mus rau 100-200 degree thiab poob ib feem ntawm cov dej siv lead ua. Nws yog cov khoom siv cua-hardening cementitious nrog ob daim ntawv, thiab, ob qho tib si uas yog rhombic muaju, tab sis nrog lub cev sib txawv. -type hemihydrate gypsum crystals zoo thiab ruaj khov; -type hemihydrate gypsum yog ib qho flaky thiab tawg siv lead ua, cov siv lead ua zoo heev, thiab thaj chaw tshwj xeeb yog loj dua li ntawm -type hemihydrate gypsum.
Thaum tsim cov khoom siv gypsum, -type hemihydrate gypsum yuav tsum muaj dej tsawg dua -hom gypsum, thiab cov khoom muaj ntau dua ntom ntom thiab lub zog. Feem ntau, -type hemihydrate gypsum, tseem hu ua high-strength gypsum, yog tsim los ntawm steaming nyob rau hauv ib tug saturated chav nruab nrab nrog ib tug autoclave; plaster. Tshuaj gypsum, ib yam khoom los ntawm kev lag luam, muaj cov khoom zoo ib yam li ntuj gypsum yam tsis muaj kev ua haujlwm ntau. Lub slurry ntawm hemihydrate gypsum tov nrog dej re-forms dihydrate gypsum, uas sai sai solidifies thiab hardens thaum ziab kom muaj zog, tab sis softens thaum raug dej.
Gypsum yog cov khoom siv tseem ceeb rau kev tsim cov gypsum cementitious cov ntaub ntawv thiab cov khoom siv hauv tsev gypsum, nrog rau cov retarder rau Portland cement. Tom qab cov gypsum yog calcined ntawm 600-800 degree, ib tug me me ntawm txiv qaub thiab lwm yam catalysts yog ntxiv rau grind nws ua ke kom tau anhydrite cement (tseem hu ua Jin's cement); Tom qab calcined ntawm 900-1000 degree thiab hauv av, high-temperature calcined gypsum tuaj yeem tau. . Cov khoom tsim nrog ob hom gypsum no muaj lub zog ntau dua li cov khoom siv gypsum, thiab cov anhydrite binder muaj cov rwb thaiv tsev zoo dua, thiab qhov kub-calcined gypsum tau zoo dua hnav tsis kam thiab dej tsis kam.
