水淬含钛高炉渣中硅酸解行为的研究

对水淬含钛高炉渣中硅的酸解行为进行了研究。主要考察了硫酸浓度、反应温度及渣酸比等因素对硅溶解和析出的影响,并对酸浸渣进行了表征。研究表明:采用20%硫酸分解高炉渣时,生成的水合二氧化硅在溶液中具有很高的过饱和稳定性;当酸浓度增至30%时,随着浸出的进行,溶解的硅逐渐析出;而当采用50%硫酸时,硅在整个浸出过程中均不进入溶液。硅的上述溶析行为可能与体系中离子强度的快速变化、生成硫酸钙的水合结晶以及溶液中氢离子的极强的水化能力、催化聚合作用等因素有关。

A Study on Acidulation Behavior of the Silicon-containing Material in Water-quenched Ti-bearing Furnace Slag

The acidulation behavior of silicates in water-quenched Ti-bearing slag with dilute sulfuric acid was investigated.Effect of acid concentration,reaction temperature and slag/acid ratio on dissolution and precipitation of silicon was tested and the XRD characterization on the acid leached residue was also conducted.The results show that the super-saturated colloidal silica formed during dissolution with 20% sulfuric acid was highly steady in solution and the silica gradually precipitated out from the silution in progress of the acidulation when leached with a 30% acid solution.A further increasing of the acid concentration up to 50% resulted the silicon in the slag remaining in the residue throughout the whole dissolution.The change in dissolution and precipitation behaviors of the silicon was discussed and attributed to the rapid increase of solution ion strength,the hydration of formed calcium sulfate crystal as well as the high hydrability and catalytic polymerization effect of H~ ion.