NurpiyentiMuhdarinaAmri, T. A.2013-07-192013-07-192013-07-19Rangga Dwijunanda Putrahttp://repository.unri.ac.id:80/handle/123456789/4541Sulfuric acid activated Cengar clay was a side product of liquid coagulant. It was obtained by calcination of the Cengar clay at 500 oC for 3 hours and then extracted with sulfuric acid with varying moles (0,2 ; 0,4 and 0,6) at 30 oC for a hour and filtered. The sulfuric acid activated clay solid then was calcined again at temperature of 230 oC for 5 hours. The sulfuric acid activated Cengar clay was characterized to identify the mineral types and Si/Al ratio. Characterization by x-ray diffraction (XRD) have generated a new mineral of bassanite at every moles of sulfuric acid, whereas the types of clay mineral that only calcined at 500 oC for 3 hours (LC500) are kaolinite, muscovite, monmorilonite, and calcite. Meanwhile, the Si/Al ratio in every sulfuric acid activated clays LC0,2, LC0,4 and LC0,6 are 1,56, 2,93 and 3,18, respectively, while the LC500 is 1,69.otherCengar claySulfuric acidBassanitOther