The invention relates to a process for producing free-flowing calcium fluoride particles from a diluted aqueous solution of hydrogen fluoride comprising the step of reacting the diluted aqueous solution of hydrogen fluoride with calcium carbonate particles at a temperature of less than 50° C. The invention further relates to the use of the free-flowing calcium fluoride particles for the manufacturing of anhydrous hydrogen fluoride.

The present invention provides a novel method for producing hydrogen fluoride which can suppress the occurrence of the pasty state over the whole process of producing hydrogen fluoride, reduce the problem of corrosion caused by sulfuric acid, and improve energy efficiency of the process. A method for producing hydrogen fluoride by reacting calcium fluoride and sulfuric acid comprises: (a) mixing and reacting calcium fluoride and sulfuric acid such that a mixture comprising calcium fluoride particles and sulfuric acid substantially maintains a form of particulate to obtain hydrogen fluoride while supplying sulfuric acid to the calcium fluoride particles at a flow rate of 0.002 to 1 mol/min relative to 1 mol of calcium fluoride to such an amount that a molar ratio of sulfuric acid/calcium fluoride is 0.9 to 1.1.

The present invention provides a novel method for producing hydrogen fluoride which can suppress the occurrence of the pasty state over the whole process of producing hydrogen fluoride, reduce the problem of corrosion caused by sulfuric acid, and improve energy efficiency of the process. A method for producing hydrogen fluoride by reacting calcium fluoride and sulfuric acid comprises: (a) mixing and reacting calcium fluoride and sulfuric acid such that a mixture comprising calcium fluoride particles and sulfuric acid substantially maintains a form of particulate to obtain hydrogen fluoride while supplying sulfuric acid to the calcium fluoride particles at a flow rate of 0.002 to 1 mol/min relative to 1 mol of calcium fluoride to such an amount that a molar ratio of sulfuric acid/calcium fluoride is 0.9 to 1.1.

The present invention provides a novel method for producing hydrogen fluoride which can suppress the occurrence of the pasty state over the whole process of producing hydrogen fluoride, reduce the problem of corrosion caused by sulfuric acid, and improve energy efficiency of the process. A method for producing hydrogen fluoride by reacting calcium fluoride and sulfuric acid comprises: (a) mixing and reacting calcium fluoride and sulfuric acid such that a mixture comprising calcium fluoride particles and sulfuric acid substantially maintains a form of particulate to obtain hydrogen fluoride while supplying sulfuric acid to the calcium fluoride particles at a flow rate of 0.002 to 1 mol/min relative to 1 mol of calcium fluoride to such an amount that a molar ratio of sulfuric acid/calcium fluoride is 0.9 to 1.1.

The present invention provides a novel method for producing hydrogen fluoride which can suppress the occurrence of the pasty state over the whole process of producing hydrogen fluoride, reduce the problem of corrosion caused by sulfuric acid, and improve energy efficiency of the process. A method for producing hydrogen fluoride by reacting calcium fluoride and sulfuric acid comprises: (a) mixing and reacting calcium fluoride and sulfuric acid such that a mixture comprising calcium fluoride particles and sulfuric acid substantially maintains a form of particulate to obtain hydrogen fluoride while supplying sulfuric acid to the calcium fluoride particles at a flow rate of 0.002 to 1 mol/min relative to 1 mol of calcium fluoride to such an amount that a molar ratio of sulfuric acid/calcium fluoride is 0.9 to 1.1.

The present invention provides a novel method for producing hydrogen fluoride, which is capable of using various calcium fluoride sources and preventing a second pasty state from occurring, effectively. In a method for producing hydrogen fluoride by reacting calcium fluoride with sulfuric acid, following steps are conducted: (a) a step for mixing and reacting calcium fluoride particles having an average particle diameter of 1-40 m with sulfuric acid at a sulfuric acid/calcium fluoride molar ratio of 0.9-1.1 under a temperature of 0-70 C. to obtain a solid-state reaction mixture; and (b) a step for heating the solid-state reaction mixture to a temperature of 100-200 C. to react with itself, and thereby producing hydrogen fluoride in a gas phase.