Method of purifying sodium metal

Abstract

An apparatus for purifying sodium metal including: a top flange, a transparent slice, a hollow flange, a vacuum distillation kettle, gaskets, and bolts. With this apparatus, solid sodium is liquefied by heating. The volatile impurities contained in the liquid sodium metal evaporate out of the vacuum pump. After heating the liquid sodium to a high temperature, circulating cooling water is added to the condenser tube by radiation-auxiliary distillation. High-purity argon is then added to remove volatile impurities, and thermal radiation is performed to accelerate the evaporation rate at the surface of the liquid sodium. Consequently, gaseous sodium rapidly condenses on the condenser tube and becomes solid sodium.

Claims

1. An apparatus for purifying a sodium metal, comprising: a top flange; a transparent slice; a hollow flange; a vacuum distillation kettle; a plurality of gaskets; and a plurality of bolts; wherein the top flange, the transparent slice, the hollow flange, and the vacuum distillation kettle are fastened by the plurality of bolts, with an order that the top flange is on the top, the transparent slice is located between the top flange and the hollow flange, and the vacuum distillation kettle is at the bottom; the plurality of gaskets are disposed between every two adjacent components to construct a sealed whole.

2. The apparatus according to claim 1, wherein the transparent slice is selected from the group consisting of quartz, calcium fluoride, magnesium fluoride, transparent fluorine plastic, and corrosion-resistant glass.

3. The apparatus according to claim 1, wherein the hollow flange further comprises at least one condensation water import, at least one condensation water export, a suction hole, and an air inlet; wherein a cooling coil is disposed between the condensation water import and the condensation water export; the suction hole is connected to a vacuum pump through a first one-way valve; the air inlet is connected to a high-purity argon tank through a second one-way valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a cross-sectional view of the apparatus of the present invention.

(2) FIG. 2 shows a plan view of the top flange.

(3) FIG. 3 shows a structure diagram of the hollow.

(4) FIG. 4 shows a plan view of the hollow flange of the present invention.

(5) FIG. 5 shows a flow diagram of the method to purify the sodium.

DETAILED DESCRIPTION OF THE INVENTION

(6) The following combination of the accompanying drawings described the method of the invention.

(7) Solid sodium metal (with 99.5% purity) as raw material is placed in the distillation kettle body 4, as shown in FIG. 1. The apparatus is placed on the heating furnace. 1 is a top flange, 2 is a transparent slice, 3 is a hollow flange, and 5 is gaskets. The hollow flange 3 comprises condensation water imports 7, condensation water exports 9, a suction hole 6, and an air inlet 8. The suction hole 6 is attached through a one-way valve 10 connected to a vacuum pump. The air inlet 8 entry is attached through the one-way valve 10 with high-purity argon gas. The converging tube is placed close to the conical surface of the transparent slice 2. The top of the converging tube has a set of infrared radiation lamps.

(8) The technological process is shown in FIG. 5.

(9) First, an infrared radiation lamp is used to heat liquid sodium and control the temperature at 240 C. to 260 C. The vacuum degree is less than or equal to 10 Pa. The heating time is 2 h. High-purity argon is added twice to the apparatus to remove volatile impurities. Solid sodium is heated into liquid sodium. The volatile impurities contained in the liquid sodium metal are evaporated out of the vacuum pump.

(10) Second, the apparatus is placed on a heating furnace to increase the temperature of liquid sodium to 400 C. Circulating cooling water is then added to the condenser tube by radiation-auxiliary distillation. Thermal radiation is used to accelerate the evaporation rate at surface temperature of sodium. Thus, gaseous sodium rapidly condenses on the condenser tube and becomes solid sodium. Thermal radiation-auxiliary distillation is finally realized to refine sodium metal.

(11) The purification of sodium metal is determined by inductively coupled plasma optical emission spectrometry. The total impurity content is less than 0.01%.