Production of hydrogen fluoride and metal sulfates

Abstract

Abstract IN THE PRODUCTION OF HYDROGEN FLUORIDE AND A METAL SULFATE BY THE REACTION OF A METAL FLUORIDE WITH SULFURIC ACID IN AN AQUEOUS SUSPENSION AT AN ELEVATED TEMPERATURE UP TO ABOUT 350*F., THE IMPROVEMENT WHICH COMPRISES (A) IN A FIRST STAGE CONTACTING THE METAL FLUORIDE WITH ABOUT 1.2 TO 11 TIMES THE STOICHIOMETRIC AMOUNT OF ABOUT 20 TO 100% SULFURIC ACID AT AN ELEVATED TEMPERATURE UP TO ABOUT 300*C., AND SEPARATING HYDROGEN FLUORIDE FORMED, AND (B) PASSING THE REACTION MASS TO A SECOND STAGE, SEPARATING THE LIQUID PHASE IN SAID SECOND STAGE, AND RECYCLING THE LIQUID TO SAID FIRST STAGE. ADVANTAGEOUSLY TO REACTION IS COMPLETED IN A THIRD STAGE AT 50 TO 350*C. CARRIED OUT ON THE SOLID RESIDUE FROM THE SECOND STAGE, LIQUID FROM THE SECOND STAGE BEING RECYCLED TO THE FIRST STAGE. TO SUPPLY SOME OF THE HEAT OF REACTION, THE SULFURIC AND/OR OXIDES OR HYDROXIDES OF FROM SULFUR TRIOXIDE AND.OR /OR OXIDE OR HYDROXIDES OF ALKALI OR ALKALINE EARTH METALS MAY BE ADDED. SUCH ADDITIVES, OR OTHERS SUCH AS POTASSIUM OR IRON SULFATE, WILL ALSO AFFECT THE GRAIN SIZE AND SHAPE OF THE METAL SULFATE PRODUCED BY THE PRIMARY REACTION. WHEN THE METAL FLUORIDE IS CALCIUM FLUORIDE, THE EXTENT OF HYDRATION OF THE CALCIUM SULFATE PRODUCT CAN BE PREDETERMINED BY FOLLOWING THE REACTION CONDITIONS SET OUT IN FIG. 1.

Inventors

• 👤 E Eipeltauer
• 👤 H Lauss
• 👤 B Spreckelmeyer

Bibliographic Details