PROCESS FOR THE REMOVAL OF FLUORIDE FROM ALKALINE HYDROXIDE SOLUTIONS

• Main Authors: Seeler, Fabian, Gerke, Birgit, Born, Nils-Olof Joachim, Vogelsang, Regina, Rohde, Wolfgang, Schierle-Arndt, Kerstin, Giacomini, Mattia
• Format: Patent
• Language: English
• Published: 21.12.2023
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM,RUBIDIUM, CAESIUM, OR FRANCIUM; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INORGANIC CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PRETREATMENT OF RAW MATERIALS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; PRODUCTION AND REFINING OF METALS; THEIR RELEVANT APPARATUS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A process for extracting fluoride from a solution of high pH comprising more than 0.1 mol of alkaline hydroxide and/or alcoholate per liter dissolved in a polar solvent is described. The polar solvent is chosen from water, lower alcohols, and mixtures thereof. The process is characterized in that the solution liquid is contacted with a solid phase adsorbent chosen from a) alkaline earth salts comprising carbonate anions, oxo anions, sulphate anions, or phosphate anions, and alkaline earth salts comprising a mixture of such anions or a mixture of such anions with hydroxyl anions, and b) cation binding resins loaded with one or more 3-valent cations, chosen from 3-valent cations of Al, Ga, In, Fe, Cr, Sc, Y, La and lanthanoides.