Method 1: a preparation technique of lithium tetrafluoroborate, comprising the adhering to actions:
1) According to the proportion of the mole ratio of H3BO3 to HF of 1:4 ～ 6, including boric acid to hydrofluoric acid to respond to acquire a fluoroboric acid option;
2) According to the proportion of Li to B molar ratio of 1.05 to 1.5:1, take the lithium substance as well as add it to the fluoroboric acid service acquired in step 1) to react to acquire a lithium tetrafluoroborate remedy;
3) Focus the lithium tetrafluoroborate option gotten symphonious 2), take shape by air conditioning, and also filter to get lithium tetrafluoroborate crystals;
4) drying out the lithium tetrafluoroborate crystals obtained in step 3) to get an unrefined lithium tetrafluoroborate;
5) The unrefined lithium tetrafluoroborate gotten symphonious 4) is put in an activator, and also fluorine gas or a fluorine-nitrogen combined gas is presented to respond to get the lithium tetrafluoroborate.
Method 2: a preparation technique of high-purity lithium tetrafluoroborate, making up the adhering to steps:
( 1) Under the problem of -10 ℃ ～ 10 ℃, slowly include boric acid to the hydrofluoric acid solution, regulate the molar ratio of boric acid and anhydrous hydrofluoric acid to be: H3BO3: HF= 1:( 4 ～ 6), then proceed Stir, react for 0.5-5h, as well as prepare a fluoroboric acid remedy;
( 2) Under the problem of -10 ℃ ～ 15 ℃, the lithium substance is included in the fluoroboric acid option acquired symphonious (1) according to the molar ratio Li: B= 1.05 ～ 1.5, and the reaction is stirred for 0.5-5h to get tetrafluoroethylene Lithium borate remedy;
( 3) The lithium tetrafluoroborate option is concentrated under the conditions of -0.05 ～ -0.09 MPa and also 50 ° C ～ 90 ° C, concentrated to 1/3 ～ 1/8 of the original volume of the lithium tetrafluoroborate option, and after that lowered to space temperature level Formation by cooling down, filtering system, the obtained solid is lithium tetrafluoroborate crystal;
( 4) The lithium tetrafluoroborate crystal is originally dried out at 30-60 ° C for 2-8h, and then vacuum-dried at 50-100 ° C for 2-8h to obtain a crude lithium tetrafluoroborate;
( 5) the lithium tetrafluoroborate crude item acquired symphonious (4) is dissolved in anhydrous hydrofluoric acid to obtain a response option, as well as the response temperature is controlled from 0 ° C to 15 ° C, and fluorine gas or fluorine-nitrogen blended gas is entered the reaction remedy Execute pollutant removal, where the consumption of fluorine gas is: the mole number of fluorine gas: the mole number of crystal water=( 1.5 ～ 15) in the lithium tetrafluoroborate unrefined product: 1, it is confirmed by experiments that under this problem, lithium tetrafluoroborate The impurity elimination effect in the crude item is excellent, the acquired product has high pureness, as well as the lithium tetrafluoroborate hydrofluoric acid mommy liquor is acquired after removing contaminations by fluorine;
( 6) Gradient cooling and formation of the lithium tetrafluoroborate hydrofluoric acid mom liquor, the condensation temperature is -40 ~ 0 ℃, filter, and the condensation item is dried out at 30 ~ 80 ℃ under nitrogen security to acquire a high-purity lithium tetrafluoroborate item, Filtrate recuperation and recycling.