JPS6010761B2 - crystallizer - Google Patents

Description

[Detailed description of the invention] The present invention relates to a crystallization bag fixer.

More specifically, in order to obtain crystals of metal salts, the organic solvent from which the metal ions have been extracted is mixed with an aqueous stripping solution (liquid to be concentrated) to remove the metal ions from the organic phase, without concentrating by evaporation of water. This invention relates to a crystal folding machine that obtains crystals of metal salts by concentrating teeth of a desired metal in male and female liquids and completely separates them from organic solvents.

As a related matter, the method used to obtain crystals of metal salts is to condense water in a crystallization bag by evaporation and precipitate crystals due to the difference in solubility of the salts, but as a method to save the energy required for evaporation, In addition to vacuum evaporation, a multistage depressurization method is used to enhance this effect.

In addition, in solutions containing substances with large solubility differences depending on temperature, crystallization is performed by cooling, but the metal ions in the solution before crystallization are It is common to increase the concentration by separately dissolving it. In this way, in conventional methods, it is necessary to increase the concentration by evaporating water or separately dissolving crystallized substances by changing the temperature of the solution in order to increase the desired concentration of Kanao ions in the treatment solution. There was a point where the energy dissipation was large.

On the other hand, in the field of solvent extraction technology, when extracting metal ions extracted into an organic phase as a salt, if the dilution solution used is an aqueous solution in which the target metal ion has a low solubility, crystallization occurs in a mixing chamber with an organic solvent. The crystals will crystallize and adhere to the walls of the mixing plant and the Koji Azusa blades, making it difficult to operate the mixing pot stably for long periods of time.In addition, a large amount of expensive organic solvent will adhere to the crystals, reducing economic efficiency. There was a drawback to that.

In particular, since the solubility of salts such as metal ammonium fluoride and metal ammonium sulfate is low, this phenomenon is remarkable and has hindered industrial use. From such a thing,
In industrial methods that utilize solvent extraction technology to recover crystals, when removing metal ions from organic solvents, a highly soluble aqueous solution is used to thermally extract the desired metal ions from the Utsuru phase. After that, the method of obtaining crystals using crystallization rhyoma, which performs evaporation and concentration, which has been used since then, was adopted.
The current situation is that economic efficiency is declining due to soaring energy costs.

The present invention alleviates the drawbacks of the conventional method, and makes it possible to utilize an aqueous solution with low solubility for stripping a desired metal ion from an organic phase.
In addition, the present invention provides an energy-saving type of crystal folding rhombus that produces uniform crystal grains without evaporating water.

The present invention provides a mixing zone for an organic solvent and a thermogenic fluid provided in an upper section of a lower inverted conical crystal fold bag counterfeit body, and an overflow of organic solvent from a mixing zone disposed outside the mixing zone. a lower open organic solvent static zone for containing and pacifying the flow; an inverted pyramidal crystal growth zone directly connected to the lower part of the body upper zone; a crystal growth zone directly connecting the lower end of the mixing zone to the body upper zone; The present invention relates to a crystallization crystallization machine characterized by being provided with a lower end opening downward slope that extends to a lower end.

The details of the present invention will be specifically explained based on the drawings, but the present invention is not limited thereto.

First, the crystallization method of the present invention will be explained with reference to FIG.

The organic solvent (organic phase) 2 containing extracted metal ions and the aqueous stripping solution 3 are introduced into a mixing tank 4, and here the rope azusa device 14 is introduced.
Under the action of , the metal ions in the organic phase 2 are stripped into a stripping solution (aqueous solution) 3 in which the metal ion-containing compound has a low solubility, and the stripping solution 3 in which the concentration of the metal compound to be crystallized is increased has a specific gravity difference. The organic solvent is separated in the downcomer pipe 6 and the crystal nuclei of the nuclear compound are grown while descending to the crystal growth zone 7 which has an inverted conical cross section, and most of the separated organic solvent is transferred to the mixing barrel. 4 overflows into the static pupil area 5 and is stored on the stripping solution, then overflows from the area 5 and is discharged from the organic solvent outlet 11. Note that the organic solvent attached to the crystal in the crystal growth zone 7 is peeled off as the crystal grows, and the crystal becomes solvent-free. The stripping solution flows upward while crystallizing and growing the crystals in the crystal growth zone 7, and as its cross-sectional area increases, the rising speed decreases and the accompanying crystals settle, while flowing into the upper part of the inverted conical crystal growth zone. After separating the nearly crystallized crystals at the junction with the cylindrical cross section above the crystallizer (crystal separation zone 13), some are separated from the fishing liquid outlet 10, and the others are separated from the circulating stripping liquid outlet. 16, the stripping liquid 3 is recirculated to the mixing tank 4 by the circulation pump 9, and a part of it is sent to the crystal flowing liquid inlet 8 provided at the bottom of the crystallizer main body 1, from where it passes through the grid 15 and collects the crystals. It is introduced into the lower part of the growth zone 7 to promote the flow of crystals and prevent the crystals from settling and accumulating in the lower part of the crystal growth zone. The crystals are discharged as a slurry from crystal discharge pipes 12 provided at predetermined positions of the inverted conical portion, and subjected to the subsequent separation process. Figure 2 shows one of the modification devices for this original ball device.
An example of a standing orchid map is shown.

FIG. 2 shows that when the solubility of the metal compound to be crystallized in the fishing liquid is high, the stripping solution discharged from the circulating stripping solution outlet 16 is cooled by a cooler or a heater 17 so that the crystal growth zone 7 can be cooled. No. 1, except that crystallization can be promoted by lowering the temperature of the stripping solution.
It is similar to the figure. When the solubility of the metal compound to be crystallized in the stripping solution is low, contrary to the case shown in FIG. The structure is the same as in FIG. 1 except that excessive crystallization in the droplet 4 or the downcomer 6 is prevented by increasing the stiffness.

Note that heating and cooling may be performed by introducing steam or cold butterfly 18 to the cooler or heater 17 as needed.

As described above, the present invention makes it possible to obtain uniform crystals without evaporating water and concentrating the metal ions extracted into an organic solvent by using a stripping solution in which the solubility of the target metal or salt is low. It is a crystal ori rhombus that makes it possible to prevent large losses of organic solvents due to organic solvents adhering to the formed crystals.

Next, the operation of the apparatus of the present invention will be described with reference to examples.

Example 1 Organic solvent 2 obtained by extracting 12.6 times of Fe30 ions was added to an organic solvent prepared by diluting 30% D2EHPA (di-2-ethylhexyl phosphoric acid) extractant with 70% normal paraffin at a rate of 10 times/hour. The mixture was supplied to the mixing tank 4 of the crystallizer shown in FIG.

(N ratio) 8FeF6 for 4.5 evenings/so dissolved N day F2
100 tons of the aqueous solution (stripping solution) 3 was supplied to the mixing tank 4 of the crystallizer main body 1 shown in FIG. 1 at a rate of 20 tons/hour. The Fe30 ions in the organic phase are separated from the organic phase 2 to the aqueous phase (aqueous stripping solution 3) as shown in the following formula, (N ratio) 8FeF6
is generated. R3Fe+ is HHF2 Koha/Hiju (NH4
)zueF6↓・・・・・・・・・・・・・0}R・day indicates the regenerated organic solvent, and R3Fe indicates the organic solvent from which the Fe30 ions were extracted. In the conventional mixer-settler type Hishitaka, crystals about the size of 3Q broadside adhered to the inner circumference of the mixing tank after 3 hours of operation, and crystals adhered to the Azusa rope blades to the extent that the turbine blades were completely obscured by the crystals. , after 5 hours,
The mixing became so poor that the Fe30 ions in the organic solvent could not be separated. Further, the size of the crystals obtained was about 2 to 10 Buddhas. On the other hand, in the device of the present invention, 12q
When the rope Azusa blade was inspected after an hour, there was no adhesion inside the mixing tank 4 except for a thin crystal adhesion of about 1 to 0.5 fields.

Furthermore, in the crystal growth zone 7, it was confirmed with the naked eye that the organic solvent was separated as the crystal nuclei grew. The discharged crystals were uniform particles of 50 to 70 r. Differences other than crystal size are shown in Table 1. Table 1 (NH4)3F in NH4HF2 (HF=0 evening/evening) liquid
The solubility of eF6 is a small value as shown in Figure 4, and crystals can be obtained by stripping Fe30 ions from the organic phase without evaporating water and concentrating it. As a result, crystals can be stably obtained with little organic solvent adhesion.

Example 2 V03- ion was extracted in the organic solvent 2 prepared by diluting 10% TOA (trioctylamine) with an aromatic hydrocarbon at a ratio of 6 t', and on the other hand, 4 mol/ZNAC 1 and carp 8 stripping solution 3 were mixed. Offerings were made to tank 4 at a rate of 10 hours/hour.

By mixing both liquids, a reaction as shown in formula (■) occurs, and V of the organic phase
03-Ion moves to the aqueous phase, and at the same time, crystals with an N ratio of V03 are generated in the aqueous phase. (R3NH 10) V03-1NH'1 (
R3NH 10) CI-+NHV03↓.・・・・・・・・・
．．・・・． ...[2] In the conventional mixer-settler type peeling device, crystals precipitated in the mixing tank as in Example 1 and adhered to the inner circumference of the rice cake and the koji-azusa blades, making continuous operation for more than 3 q hours difficult. Ta. The obtained crystals were less than 20 1, had a lot of organic solvent attached to them, were clay-like, separated, and had to be redissolved and recrystallized. 100 to 150 can be safely driven by the present invention.
'' crystals were obtained.

Table 2 shows the differences in the operating results of both devices.

Table 2: After peeling, the amount of crystals that penetrate into the organic solvent is very small compared to the conventional method, which is confirmed by visual observation that the crystal transparency is higher than that of the crystals from the conventional mixer settler. It was done.

With the device of the present invention, an aqueous solution with low solubility of the target metal salt can also be used as an organic solvent stripping solution, so metal ions extracted into the organic phase can be stripped repeatedly without evaporating water or cooling. Crystals can be obtained by this method.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal sectional view of a crystallizer according to the invention. FIGS. 2 and 3 show elevational views of the modified rhombus shown in FIG. 1, which has been modified according to the invention. FIG. 4 is a diagram showing the solubility of 3FeF6 (N ratio). 1... Crystallizer main body, 2... Organic solvent (organic phase), 3.
...Aqueous stripper, 4...Mixing tank, 5...
...Quiet area, 6... Downpipe, 7... Crystal growth zone, 8... Crystal flow liquid inlet, 9... Circulation pump, 10...・Removal liquid outlet, 11...
...Organic solvent outlet, 12...Crystal discharge pipe, 1
3...Crystal separation zone, 14...Hashiazusa device, 15...Grate, 16...Circulating stripping liquid outlet, 17...Cooler or heater , 18...
・Steam or soot. Eagle - Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 Mixing zone for organic solvent and stripping solution provided in the upper section of the lower inverted conical crystallizer main body, containing the overflow of organic solvent from the mixing zone located outside the mixing zone - Stand still an inverted pyramidal crystal growth zone directly connected to the lower part of the upper body area; a lower end open downcomer extending from the lower end of the mixing zone to the crystal growth zone directly connected to the upper body area; A crystallizer characterized by comprising: