Influence of disodium hydrogen phosphate dodecahydrate on hydrothermal formation of hemihydrate calc

• 作 者: Qing Han Kangbi Luo Huping Li Lan Xiang
• 机 构: College of Chemical Engineering,Kunming University of Science and Technology,Department of Chemical
• 出 处: Particuology
• 发表日期: 2014年06期

The influence of Na_2HPO_4·12H_2O on the hydrothermal formation of hemihydrate calcium sulfate(CaSO_4·0.5H_2O) whiskers from dihydrate calcium sulfate(CaSO_4·2H_2O)at 135 ℃ was investigated.Experimental results indicate that the addition of phosphorus accelerates the hydrothermal conversion of CaSO_4·2H_2O to CaSO_4·0.5H_2O via the formation of Ca_3(PO_4)_2 and produces CaSO_4-0.5H_2O whiskers with thinner diameters and shorter lengths.Compared with the blank experiment without Na_2HPO_4·12H_2O,the existence of minor amounts(8.65 ×10~(-4)-4.36 × 10~(-3) mol/L) of Na_2HPO_4·12H_2O led to a decrease in the diameter of CaSO_4·0.5H_2O whiskers from 1.0-10.0 to 0.5-2.0 μm and lengths from 70-300 to50-200 μm.

The influence of Na_2HPO_4 · 12H_2O on the hydrothermal formation of hemihydrate calcium sulfate (CaSO_4 · 0.5H_2O) whiskers from dihydrate calcium sulfate (CaSO_4 · 2H_2O) at 135 ° C was investigated. Experimental results indicate that the addition of phosphorus accelerates the hydrothermal conversion of CaSO_4 · 2H_2O to CaSO_4 · 0.5H_2O via the formation of Ca_3 (PO_4) _2 and CaSO_4-0.5H_2O whiskers with thinner diameters and shorter lengths. Compared with the blank experiment without Na_2HPO_4 · 12H_2O, the existence of minor amounts (8.65 × 10 ~ (-4) -4.36 × 10 ~ (-3) mol / L) of Na_2HPO_4 · 12H_2O led to a decrease in the diameter of CaSO_4 · 0.5H_2O whiskers from 1.0-10.0 to 0.5-2.0 μm and lengths from 70-300 to 50 -200 μm.