论文信息 - Phase Diagram for the NaOH–Al2O3–Na2CrO4–H2O System at (120 and 130) °C

Phase Diagram for the NaOH–Al2O3–Na2CrO4–H2O System at (120 and 130) °C

The phase diagrams of the NaOH-Al2O3–Na2CrO4–H2O system at (120 and 130) °C and in full NaOH concentration range were determined, and the crystallization zones of each solid were analyzed and discussed. The results show that Na2CrO4, Al2O3·3H2O, Na2O·Al2O3·1.25H2O, Na2O·Al2O3·2.5H2O, and NaOH are present as solid phases in the system at 120 °C, and Na2CrO4, Al2O3·H2O, Na2O·Al2O3·1.25H2O, Na2O·Al2O3·2.5H2O, Na2O·Al2O3, and NaOH are present as solid phases in the system at 130 °C. These results can provide a basis for the separation of Na2CrO4 and Al2O3 from the concentrated alkali solution in the chromate cleaner production process.

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