Method for preparing an electrolyte and an electrolyte replenishment system during aluminum electrolysis process

Abstract

The disclosure provides a method for preparing an electrolyte and an electrolyte replenishment system during an electrolytic process. The method includes the following steps: Step A: placing aluminum in a reactor, vacuumizing the reactor and feeding an inert gas, heating the reactor to 700-850 degrees centigrade, and adding one or more of potassium fluozirconate, potassium fluoborate, sodium hexafluorozirconate and sodium fluoroborate; and Step B: stirring the reactants for 4-6 hours and extracting the upper molten liquid to obtain an electrolyte replenishment system during an aluminum electrolysis process. The disclosure has the following beneficial effects: when used in the aluminum electrolysis industry, the electrolyte system provided herein can be directly used as an aluminum electrolyte or a replenishment system in an electrolyte without changing existing electrolysis technology to significantly reduce an electrolysis temperature during an aluminum electrolysis process.

Claims

1. A method for preparing an electrolyte comprising the following steps of: Step A: placing aluminum in a reactor, vacuumizing the reactor and feeding an inert gas, heating the reactor to 700-850 degrees centigrade, and adding only potassium fluozirconate; and Step B: stirring for 4-6 hours and extracting an upper molten liquid to obtain only zirconium sponge and an $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$ electrolyte according to a reaction formula of $\mathrm{Al}+\frac{3}{4}{K}_2{\mathrm{ZrF}}_6=\frac{3}{4}\mathrm{Zr}+\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$ so as to replenish the $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$ electrolyte during an electrolytic process.

2. A method for preparing an electrolyte during an electrolytic process, including the steps of: Step A: placing aluminum in a first reactor, vacuumizing the first reactor and feeding inert gas, heating the first reactor to 700-850 degrees centigrade, adding only a first reactant of potassium fluozirconate, stirring 4-6 hours and extracting a first upper molten liquid to obtain only zirconium sponge and a potassium AlF.sub.3 cryolite; and placing aluminum in a second reactor, vacuumizing the second reactor and feeding inert gas, heating the second reactor to 700-850 degrees centigrade, adding only a second reactant of sodium hexafluorozirconate, stirring for 4-6 hours and extracting a second upper molten liquid to obtain only zirconium sponge and a sodium AlF.sub.3 cryolite; and Step B: mixing the obtained potassium cryolite with the obtained sodium cryolite in a molar ratio of 1:1 to 1:3.

3. The method for preparing an electrolyte during an electrolytic process according to claim 2, comprising the steps of: in said Step A: extracting the first upper molten liquid to obtain the potassium cryolite the molecular formula of which is $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3;$ and extracting the second upper molten liquid to obtain the sodium cryolite the molecular formula of which is $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_{3;}$ and in said Step B: mixing the obtained potassium cryolite $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$ with the obtained sodium cryolite $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$ in a molar ratio of 1:1 to 1:3.

4. A method for preparing an electrolyte comprising the steps of: Step A: placing aluminum in a reactor, vacuumizing the reactor and feeding an inert gas, heating the reactor to 700-850 degrees centigrade, and adding only sodium hexafluorozirconate; and Step B: stirring for 4-6 hours and extracting an upper molten liquid to obtain only zirconium sponge and an $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$ electrolyte during an aluminum electrolysis process according to a reaction formula of $\mathrm{Al}+\frac{3}{4}{\mathrm{Na}}_2{\mathrm{ZrF}}_6=\frac{3}{4}\mathrm{Zr}+\frac{3}{2}\mathrm{Na}F.Math.{\mathrm{AlF}}_3.$

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) The disclosure is described below in detail with reference to specific embodiments.

Embodiment 1

(2) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry potassium fluozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a potassium cryolite

(3) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite

(4) 0$\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
is pumped out using a siphon pump.

(5) The electrolyte

(6) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
generated during the aluminum electrolysis process is added into the continuously consumed fundamental system of the electrolyte to obviously reduce the electrolysis temperature, finally reducing the electrolysis temperature to 820 to 850 degrees centigrade. As the potassium cryolite

(7) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
is more corrosive than trisodium hexafluoroaluminate, an electrolytic bath needs to have an inactive anode or an anode subjected to an inactive surface processing so as to be prolonged in service life.

Embodiment 2

(8) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry sodium hexafluorozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a sodium cryolite

(9) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite

(10) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
is pumped out using a siphon pump.

(11) The electrolyte

(12) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
generated during the aluminum electrolysis process is added into the continuously consumed fundamental system of the electrolyte to obviously reduce the electrolysis temperature, finally reducing the electrolysis temperature to 820 to 850 degrees centigrade. As the sodium cryolite

(13) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
is more corrosive than trisodium hexafluoroaluminate, an electrolytic bath needs to have an inactive anode or an anode subjected to an inactive surface processing so as to be prolonged in service life.

Embodiment 3

(14) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of potassium fluoborate and potassium fluozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a potassium cryolite

(15) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite

(16) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
is pumped out using a siphon pump.

(17) The electrolyte

(18) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
generated during the aluminum electrolysis process is added into the continuously consumed fundamental system of the electrolyte to obviously reduce the electrolysis temperature, finally reducing the electrolysis temperature to 900 to 930 degrees centigrade.

Embodiment 3

(19) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of sodium fluoborate and sodium hexafluorozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a sodium cryolite

(20) 0$\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite

(21) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
is pumped out using a siphon pump.

(22) The electrolyte replenishment system

(23) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
generated during the aluminum electrolysis process is added into the continuously consumed fundamental system of the electrolyte to obviously reduce the electrolysis temperature, finally reducing the electrolysis temperature to 900 to 930 degrees centigrade.

Embodiment 4

(24) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of potassium fluoborate and potassium fluozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a potassium cryolite

(25) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite is pumped out using a siphon pump. One ton of aluminum is placed in another reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of sodium fluoborate and sodium hexafluorozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a sodium cryolite

(26) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite is pumped out using a siphon pump.

(27) A cryolite mixture obtained by mixing the prepared potassium cryolite

(28) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
with the prepared sodium cryolite

(29) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
in a molar ratio of 1:1 is directly added into an electrolytic bath, an electrolysis process is conducted using an inert electrode material or a carbon electrode material or a mixed electrode material (the combined use of carbon and an inert material) at a controlled working electrolysis temperature of 825-900 degrees centigrade, then a virgin aluminum is obtained.

Embodiment 5

(30) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry potassium fluozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a potassium cryolite

(31) $\frac{3}{2}KF.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite is pumped out using a siphon pump. One ton of aluminum is weighed and placed in another reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry sodium hexafluorozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a sodium cryolite

(32) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite is pumped out using a siphon pump.

(33) A cryolite mixture obtained by mixing the prepared potassium cryolite

(34) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
with the prepared sodium cryolite

(35) 0$\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
in a molar ratio of 1:2 is directly used as the replenishment system in an electrolyte, an electrolysis process is conducted using an inert electrode material or a carbon electrode material or a mixed electrode material (the combined use of carbon and an inert material) at a controlled working electrolysis temperature of 850-900 degrees centigrade, then a virgin aluminum is obtained.

Embodiment 6

(36) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of potassium fluoborate and potassium fluozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a potassium cryolite

(37) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite is pumped out using a siphon pump. One ton of aluminum is weighed and placed in another reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry sodium hexafluorozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a sodium cryolite

(38) $\frac{3}{2}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite is pumped out using a siphon pump.

(39) A cryolite mixture obtained by mixing the prepared potassium cryolite

(40) $\frac{6}{5}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
with the prepared sodium cryolite

(41) $\frac{3}{2}\mathrm{Na}F.Math.{\mathrm{AlF}}_3$
in a molar ratio of 1:3 is directly used as an electrolyte system, the working range of the electrolysis temperature is controlled from 850-900 degrees centigrade, an electrolysis process is conducted using an inert electrode material or a carbon electrode material or a mixed electrode material (the combined use of carbon and an inert material) at a controlled working electrolysis temperature of 850-900 degrees centigrade, then a virgin aluminum is obtained.

Embodiment 7

(42) One ton of aluminum is weighed and placed in a reactor, the reactor is vacuumized and fed with argon for protection and then heated to 800 degrees centigrade, dry potassium fluozirconate is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium sponge and a potassium cryolite

(43) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid potassium cryolite is pumped out using a siphon pump. One ton of aluminum is placed in another reactor, the reactor is vacuumized and fed with argon for protection and then heated to 750 degrees centigrade, a dry mixture consisting of sodium fluoborate and sodium hexafluorozirconate in a molar ratio of 2:1 is slowly added into the reactor in a reactive proportion, the reactants are rapidly stirred for 5 hours to generate zirconium boride and a sodium cryolite

(44) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3,$
then the cover of the reactor is opened, the upper molten liquid sodium cryolite is pumped out using a siphon pump.

(45) A cryolite mixture obtained by mixing the prepared potassium cryolite

(46) $\frac{3}{2}\mathrm{KF}.Math.{\mathrm{AlF}}_3$
with the prepared sodium cryolite

(47) $\frac{6}{5}\mathrm{NaF}.Math.{\mathrm{AlF}}_3$
in a molar ratio of 1:1 is directly used as the replenishment system in an electrolyte, an electrolysis process is conducted using an inert electrode material or a carbon electrode material or a mixed electrode material (the combined use of carbon and an inert material) at a controlled working electrolysis temperature of 850-900 degrees centigrade, then a virgin aluminum is obtained.

(48) The above is detailed description of the disclosure with reference to specific preferred embodiments which is not to be construed as limiting the disclosure. The various simple deductions or replacements that can be devised by those of ordinary skill in the art without departing from the concept of the disclosure all fall within the protection scope of the disclosure.