Hydrothermally Synthesized Products of CaO-SrO-Silicon Fume-H_2O System

In order to prove the interaction mechanism between radionuclide strontium and Portland cement(elementary composition: CaO and SiO_2)-H_2O system, the hydrothermally synthesized products of CaO-SrO-silicon fume-H_2O system at 80?℃ were studied by means of XRD、TG-DSC、SEM and their solubilities were determined too. The results showed that Sr~(2+) can replace Ca~(2+) in calcium silicate hydrate (CSH) gel to form solid solution and make the structure of CSH gel more disordered under the experimental conditions; highly crystalline 3SrO·2SiO_2·nH_2O firstly results from the reaction of SrO with silicon fume and water; dehydration of 3SrO·2SiO_2·nH_2O takes place between 290?℃ and 350?℃; calcium-strontium silicate hydrate solid solution chiefly exhibits cotton-like gel while 3SrO·2SiO_2·nH_2O exhibits prism-like crystals without intergrowth, the solubility of CSH gel whose Ca/Si ratio is 1 is 0.567 mmol·L~(-1) and the solubility of 3SrO·2SiO_2·nH_2O is higher than that of CSH gel,the former is about three times as much as the latter.