SU551040A1 - The method of purification of fluoride gases - Google Patents

Description

one

The invention relates to a method for the purification of fluorine gases containing fluorine compounds in the form of hydrogen fluoride in admixture with silicon tetrafluoride or sulfurous anhydride.

A known method of purification of fluorine gases containing hydrogen fluoride and silicon tetrafluoride by absorbing them with an aqueous solution containing at least one salt from the group: sodium sulfate, sodium chloride, sodium nitrate, potassium sulfate, potassium chloride, potassium nitrate, ammonium sulfate ammonium chloride and ammonium nitrate, preventing the formation of precipitated PRC gases in the purification process and. At the same time, the supply of sodium fluoride or soda to absorption is excluded. The hydrogen fluoride absorption process produces an aqueous solution containing at least one salt from sodium bifluoride, potassium bifluoride and ammonium bifluoride, as well as sulfuric, hydrochloric or nitric acid and, in addition, sodium, potassium, and ammonium silicofluoride.

However, with this method, the solutions contain impurities of sulfates, chlorides, or nitrates 1.

There is also known a method of purification of fluorine fluids by absorbing it with an aqueous solution containing ammonium salts and sodium fluoride, followed by treating the resulting solution with soda and separating the precipitate. The disadvantage of this process is that the ammonium carbonate formed is hydrolyzed to release ammonia and carbon dioxide. Ammonia losses are 3 wt. hours per 100 weight. sodium fluoride 2J.

To reduce ammonia losses, it is proposed to additionally add potassium carbonate to the solution at a weight ratio to sodium fluoride of 0.3-15.0: 1, O, preferably 1.5-2.0: 1.0.

The proposed method allows reducing ammonia losses to 0.6 weight. including 1OO weight. sodium fluoride.

Claims (2)

Example 1. 28000 weight. including gas in which the weight is. hours: HF 50, and dust phosphate ore Yu, passed through a solution (pH 12) composition (weight h.): N., 0 31OO, NaF - SW, KF-9, 3 K, CO, 157, (NKd ) CO 1O and NH..J 0.5. riocns the completion of the absorption process, the solution pH 2.0 of the following composition is pounded; including: 3125, NaF 102, KF 135, NH F 11. In suspension, nachocyte dust of phosphorus ore is (10 weight parts), as well as the precipitate K, Si (4 weight parts) and Na, Si F, (2 wt. H.) The weighed parts are settled, filtered and removed from the process. Together with them, 4 pounds are removed, including KF and 25 pounds. h. H, 0. At the next stage, 127 wt. Are injected into the clarified solution. hours and stirred for 30 minutes at 60 C. At the same time, 0.5 weight parts is lost. MN, and at the same time spilling. NaF precipitate, which is after sedimentation; filtering, rinsing and drying is the next product, weight by weight. including: NaF 100 and. In the filtrate, weight. h. 3100, NaF 103 KF Oe, KjCOj 146, and (Vi) CQ 10 ds Gavl 11 weight. h. and O.5 weight. h. NHj. 351 0 4 The resulting solution is returned to the purification of fluorine gases, the claims of the invention. The method of purification of fluorine gases by absorption with an aqueous solution containing ammonium salts and sodium fluoride, followed by processing the resulting solution with soda and separating the precipitate, in order the solution is additionally introduced with potassium carbonate in a weight ratio to sodium fluoride (O, 3-15.0): 1.0, preferably (1.5-2.0): 1.0. Sources of information taken into account in the examination: 1. Australian patent number 278О79, кп. 0.87.21.5, (C 01 B, B 01 D) 09/27/67. 2. USSR author's certificate No. 346715, M, Cl. B 01 B 47 / OO, 10.23.1969. (prototype).