CAJ | 학술논문

湿法磷酸生产过程副产大量磷石膏，因其含有较多杂质而无法直接利用，目前可采用硫酸酸浸处理提高磷石膏品质。为弄清酸浸过程中石膏的溶解性能和结晶形态的变化，本文探讨了在0～80℃、0～30%的硫酸浓度条件下，磷石膏在硫酸溶液中的溶解度大小、结晶形貌、物相组成及结晶水含量的变化情况。实验结果表明，磷石膏在硫酸溶液中的溶解度随温度升高而升高，在80℃时达最大；随浓度升高呈先升后降的变化，在硫酸浓度为10%时溶解度最大。硫酸浓度小于10%时，磷石膏中二水硫酸钙溶解，但无新相生成，其形貌变化不大；硫酸浓度大于10%时，二水硫酸钙溶解，同时再结晶转化成无水硫酸钙，最终导致磷石膏形貌和相态发生了改变，溶解度随硫酸浓度升高而降低。
습법린산생산과정부산대량린석고，인기함유교다잡질이무법직접이용，목전가채용류산산침처리제고린석고품질。위롱청산침과정중석고적용해성능화결정형태적변화，본문탐토료재0～80℃、0～30%적류산농도조건하，린석고재류산용액중적용해도대소、결정형모、물상조성급결정수함량적변화정황。실험결과표명，린석고재류산용액중적용해도수온도승고이승고，재80℃시체최대；수농도승고정선승후강적변화，재류산농도위10%시용해도최대。류산농도소우10%시，린석고중이수류산개용해，단무신상생성，기형모변화불대；류산농도대우10%시，이수류산개용해，동시재결정전화성무수류산개，최종도치린석고형모화상태발생료개변，용해도수류산농도승고이강저。
Phosphogypsum is a by-product in the production process of wet-process phosphoric acid. The impurities in phosphogypsum limit the usage of it. Sulfuric acid leaching processing can be used to improve the quality of phosphogypsum. In order to clarify the changes of dissolution performances and crystalline morphologies of phosphogypsum in the acid leaching process,this paper investigated the solubility size,crystal morphology,phase composition and the changes of crystal water contents of the phosphogypsum in the sulfuric acid solution at 0-80 ℃ and 0-30%of sulfuric acid concentration. The results showed that the solubility of phosphogypsum in sulfuric acid solution increased with the increasing temperature and the maximum solubility was at 80 ℃. As for the changes of concentration,the solubility increased at first and then decreased and the highest solubility occurred at the sulfuric acid concentration of 10%. When the sulfuric acid concentration was lower than 10%,the dihydrate calcium sulfate in the phosphogypsum dissolved with no new phase formation,and the morphology of phosphogypsum did not change much. When the sulfuric acid concentration was greater than 10%,the dihydrate calcium sulfate dissolved and recrystallized into the anhydrous calcium sulfate,eventually leading to the changes of phosphogypsum morphology,phase state and the increase in solubilty.