石膏性质对半水硫酸钙晶须形貌的影响

探讨了以石膏为原料,用水热法制半水硫酸钙(CaSO4.0.5H2O)晶须的可行性,侧重考察了石膏(CaSO4.2H2O)性质对水热产物形貌的影响.结果表明,以纯石膏、工业副产石膏(磷石膏、脱硫石膏)或合成石膏(由电石渣或氧化钙与硫酸反应制得)为原料,用水热法均可制备半水硫酸钙晶须.纯石膏晶粒度较大,磷石膏含杂较多,二者只能合成短棒状晶须.脱硫石膏和合成石膏的晶粒度小、含杂少,更有利于形成高长径比晶须.

Study on the hydrothermal formation of calcium sulfate whiskers

The hydrothermal formation of hemi-hydrate calcium sulfate whiskers (CaSO₄·0.5H₂O) with high aspect ratio was discussed in this paper,using various gypsums (CaSO₄·2H₂O) as the raw materials.The influence of the properties of the gypsums on the morphology of the hydrothermal products was studied.The experimental results showed that hemi-hydrate calcium sulfate whiskers can be produced under hydrothermal condition using various gypsum precursors,including the gypsum agent,the industrial gypsums (the phosphogypsum,the desulfurized gypsum),and the synthetic gypsums formed by the reaction of calcium oxide or carbide slag with sulfuric acid.Rod-shaped hmemi-hydrate calcium sulfate whiskers with low aspect ratios were formed using the crystalline gypsum agent or impurity-bearing phosphogypsum as the raw materials.Hemi-hydrate calcium sulfate whiskers with high aspect ratios were formed using the desulfurized gypsum and the synthetic gypsums with poor crystallinity and less impurities as raw materials.