| High purity strontium carbonate was mainly used in areas of electronic components, chemical reagent etc. High chemical purity (>99%), makes impurity removal process very important. High purity strontium carbonate is usually obtained through chemical purification of industrial SrCO3. Today most of domestic thick strontium carbonates depend on importation from outsea, and technology for preparation of high purity substance needs to be improved.Using crude strontium carbonate as original material, high purity strontium carbonate is generally made through acid dissolution, impurity removal and carbonization processes, and in them the key is the impurity removal process among these methods, Ca, Fe, Ba are main impurity . The dissertation mainly investigated the capability of solvent extraction to separate Ca2+,Sr2+,Ba2+, and then preparation technology of high purity strontium carbonate using chemical method to remove Ba2+,Fe3+,solvent extraction to remove Ca2+. The main contents and outcomes as following :1. Investigate extracting calcium, strontium, barium with D2EHPA, watching equilibration time, thinner, equilibration pH , temperature, extractant concentration, metal ions concentration, the outcome. It is obtained that the advantages of easy stripping, quickly phase separation belong to the technique. Better effect will be obtained if using sulfonated kerosene as thinner instead of benzene, cyclohexane. calcium can be separated from acid solution of calcium, strontium and barium, but strontium and barium can not be separated.2. Dissolving crude strontium carbonate with hydrochloric acid of certain concentration and removing barium with sulfuric acid during the process of dissolution, controlling the dissolution process to remain a little amount of crude strontium carbonate undissolved, removing iron ion by retaining the dissolution liquor neutral; after filtration, removing calcium by extracting with D2EHPA, then producing high purity strontium carbonate through reacting with NH4HCO3 . |
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