X-ray diffractrometry (XRD) was the tool to characterize crystalline of product. Figure 7 show XRD pattern of solid product without calcination. The phases detected by XRD were polycrystalline as calcium silicate (wollastonite) and calcium in Figure 8-9. After calcination at 800 C (Figure 8), the XRD patterns were well with calcium silicate (wollastonite). While calcination at 1000 C (Figure 9), the diffraction patterns were well with calcium silicate.