JPS5969103A - Separation of solvent in raffinate and/or back extraction liquid in solvent extraction method - Google Patents

Abstract

PURPOSE:To recover easily solvent in a high yield by washing the raffinate after extraction of the solvent with carbon tetrachloride. CONSTITUTION:The raffinate obtd. by subjecting an aq. soln. to be treated to an extraction treatment using TBP, etc. as a solvent is washed by CCl4. The solvent-contg. CCl4 is then separated from the raffinate and is distilled under an atmospheric pressure or reduced pressure whereby the solvent and the CCl4 are fractionated. The distillation residue obtd. after removal of CCl4 is further fed to a refining stage according to need where the residue is fractionated to pure CCl4 and a pure solvent. The solvent is thus quickly and efficiently recovered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for easily and high yield recovery of rough-t and/or solvent accompanying the back-extracted solution after carrying out a solvent extraction method. The present invention also relates to a method for separating a solvent in a back-extract solution.

Solvent extraction method has long been known as a method of analytical chemistry, but recently it has also been widely used in the field of industrial production technology. For example, in the field of general metal smelting and wastewater treatment, attempts have been made to apply this method of solvent extraction, which selectively extracts only the target metal ions from a bath solution containing various metal ions, and it has been successfully applied. .

Generally speaking, this solvent extraction method involves bringing a solvent mixed with a total extractant diluent into full contact with the aqueous solution to be treated, extracting the target ion into the total solvent, and leaving a raffinate from which target ions have been removed. It is used to obtain liquid. This raffinate is called raffinate and is sent to the next subsequent process. The target ions are extracted from the solvent, acidified, alkali, and sometimes back-extracted with water, and metals and other substances are recovered from the back-extracted liquid and recycled to the extraction process as a solvent. The typical process during this period is shown on the right side of Figure 1. Various types of extractants have been developed depending on the target ions used for this type of solvent extraction F, but an example is TBP ()! J butyl phosphate),
Versatic 1[], MIBK, naphthenic acid,
DEHPA, LIX 64, amines, KELE
X, trialkyl acid, hydroxyquinolinic acid, ether, and the like, and a typical diluent is kerosene.

One of the problems when this solvent extraction method is carried out industrially is solvent loss due to the solvent flowing into the raffinate. Since the solvent is very expensive, it is no exaggeration to say that the cost of applying the solvent extraction method is extremely low, and this solvent loss is a major problem in actual operations. There is a loss of solvent to the rough molding, a loss of the solvent becoming an emulsion and flowing out, and a loss of the solvent dissolving in the aqueous solution to be treated and flowing out, and both often occur at the same time. This solvent loss also occurs during back extraction, as the solvent flows out into the back extraction solution.
These are not only economic losses, but also
- Is the post-processing process of the extract and/or reverse extraction liquid, for example, electrowinning of metals? In some cases, the contamination of the solvent may have a negative effect on the morphology and purity of the electrodeposited metal, and in the case of wastewater treatment, there may be an increase in BOD in the wastewater or the presence of kerosene used as a diluent. The increase in oil content is also related to the applicability of the solvent extraction method, Vc, since the phosphorus content increases when the extractant is a phosphate such as TBP.

About this solvent loss to Rafiito, Flet
Data as shown in Table 1 are shown as a review of t.

Table 1 EXPEOTED 5OLVKNT LO8SES
ENGINEERING N PROCESSRAFF ENGINEERING NATES
(by Flett, D.S.) This data is for when the emulsion is kept to a minimum, and it is estimated that the solvent loss increases by H% in actual industrial operation.

The object of the present invention is to obtain Roughine-1 in this solvent extraction method.
・And/-Also, the purpose is to completely avoid solvent loss to the back-extraction solution.For this purpose, after conducting various experiments, we have found that solvent extraction processing syllable rough-height and/or back-extraction solution is completely avoided. It was found that the solvent in the raffinate and /''!! or back extract can be collected easily and in high yield by washing (scrubbing) with carbon tetrachloride. Even if the particles are present in the emulsion form in the aqueous solution or are dissolved in the aqueous solution, they can be quickly and efficiently removed.Scrubbing is the reason why such effective removal is possible. The goal is to cause new partitioning of the solvent into both the strip extract (aqueous phase) and carbon tetrachloride (organic phase) in the stage, and therefore, the lower the solvent concentration in carbon tetrachloride, the more complete the solvent is. The advantage of the method of the present invention is that the specific gravity of carbon tetrachloride (CCl4. When I contacted it with a machine, it did not form at all on the % emulsion, and I sat down and the C of 1.
There is no need to worry about secondary contamination due to Cl4 Emulshore 1c.
Compared to the extraction stage, the scrubbing stage requires a small device equipped with a powerful agitator, and since it sinks to the bottom layer when it comes into contact with an aqueous solution, when using a mixer/centrer type contactor, the It can be used in an aqueous solution and in a liquid sealed form, and phase separation after treatment can be performed easily and quickly.

According to the method of the present invention, when carrying out all the washing with CCl4 [f Raffi, Nate and/or Ushitake back extracts], pure CCl4 and the solvent can be easily extracted from the washing liquid by distillation operation under normal pressure or reduced pressure. It can be separated into

An example of the process is shown in FIG.

As shown in Figure 1, the raffinate (b) obtained from the solvent extraction step (a) is washed with CCl4 (c) in the solvent recovery step (d) of the present invention to separate the accompanying solvent. Obtain the raw material (e), and then proceed to the post-soil treatment process (e)
vc sent. On the other hand, if the solvent-containing CC14 (g) collected from the solvent recovery process (d) is separated into phases from the gold-finishing rough pipe (e), the amount of solvent contained is small. Part 11: A small portion of CCl4 is used for recycling in the solvent recovery step (d).
Can be reused by mixing with (c).

From solvent-containing 0014 (g) to solvent and cC! When collecting 14'iCl, it is sent to the distillation process (H) and distilled under normal pressure or reduced pressure to obtain pure COI as a fraction.
The distillation residue (nu) is obtained as residual oil. Since the boiling point of CCl4 is approximately 76C, this distillation process requires, for example, 100C.
When heating in a water bath near C, under reduced pressure [100mm
It is preferable to carry out heating in the same manner under a reduced pressure of about Hg. The pure CCl4 is recycled to the solvent recovery step (2) and the distillation residue (
When recovering the pure solvent from the water, it is sent to a repurification process (e.g. distillation at a high temperature under reduced pressure) to collect pure CCl4(o) and the pure solvent (water). )
get. If pure CC14 (2nd solvent recovery step (d) and pure solvent (wa) solvent extraction step (a) VC feed is reused, the solvent is lined up in a closed cycle as a whole [CC
14 can be reused.

Typical examples of the method of the present invention are listed below to specifically illustrate all the effects of the method of the present invention.

Example 1 As shown in Fig. 2, this example is about arsenic removal in which the electrolyte solution (sulfuric acid acidic aqueous solution) of copper electrolysis is subjected to solvent extraction treatment using TBPIC, J: to recover arsenic acid and total arsenite in the electrolyte solution. Method F An example in which the method of the present invention is applied is shown.The solvent extraction step (A
)' Raffinate (B) middle 1? ]-1 normal number 10
~ several i o o mg7i: of TBP is mixed into the emulsion as a dissolved component.

(i) Example T of CCl4 scrubbing step (C)
Raffinate (B) containing BP f 35.2 ppm
k, TBP? Scrubbing was performed at room temperature with a volume ratio of 1:1 of C0l4(D) vCl containing 0 parts, 1 parts, 6 parts, and 10 parts by volume. After phase separation, electrolyte solution (rough
1-(E)) and cleaning solution CF) were collected, and the TBP concentration in the electrolyte solution (rough-1(E)) was measured by the infrared absorption method of 1c-H bond, and the results are shown in Table 2. I got it.

From the results in Table 2, a raffinate (B) containing 35.2 ppm of TBP was obtained, and a raffinate (E) from which the TBP was substantially removed by the 0CI4 scrubbing process (Hvc) according to the method of the present invention was obtained. It can be seen that contamination of the electrolyte by TBP can be avoided even if it is recirculated to the electrolysis factory.

(ii) Distillation step of cleaning liquid (F) (Example of (l) (-f
:-) Washing, CCl4 containing TBP i at night (F)
However, the atmospheric pressure distillation method of CCl4'1 was carried out from this L. The test included 0CI4 containing 10g of TBP'i and ClC containing 20g of TBP'i.
Iooml of each of No. 14 was taken, and the flask bulb was immersed in boiling water and distilled under atmospheric pressure. From this vc, pure OC
I.

A fraction was obtained, and its distillation rate is shown in FIG.

FIG. 6vc also shows the case of heating with a hot water coil in a condenser, and it can be seen that the distillation rate is significantly improved by this. The obtained fraction (H) contains pure C
Because it is CI, the scrubbing process (C) can be reused. On the other hand, residual oil (1) approximately 1 of HCCl3 and TBP:
1 mixture.

(iii) Cleaning 1ffl Example (Part 2) of the distillation step (G) of (F) The distillation section was heated with boiling water and a part of the condenser was cooled with tap water.
[1% v, including CC! 14(F) f 10[] 7
171 (distilled under reduced pressure of Hg). The results are shown in Table 3.

As is clear from the results in Table 3, when vacuum distillation is repeated, the residual oil consists essentially of TBP, and the cleaning fluid (F)
1-1: Pure CCl4 fractions (H) and (K) were obtained,
Re-refining process (J) IFJ: TBP (L) can be recovered.

(IV) Example of scrubbing of back extract with CCl4 Crystal mother liquor (contains 612,31 arsenic) when copper sulfate is recovered by evaporation concentration of copper sublime solution.This crystal mother liquor is 75% TBP-25 % Keronn and solvent extraction treatment to obtain a back-extracted solution containing 25 g/l of arsenic.After reducing the arsenic acid in the solution with arsenic sulfide, a freeze-thaw treatment (N) was performed.
Slightly yellow sand-colored arsenite crystals were recovered, but before freeze-thaw treatment L/i: CC1, slabbing step (M)
By introducing 'r, pure white arsenite crystals were recovered.

Example 2 This example shows an example in which the method of the present invention was applied to raffinate that had been subjected to solvent extraction treatment with Versatic 10 in the recovery process of Ga and n contained in the zinc leaching residue. The zinc leaching residue (T7 So) is leached under pressure with sulfuric acid, and this leachate is neutralized with calcium carbonate to produce gypsum, which is concentrated in the form of hydroxide. Vereatic 1 from this plaster
By solvent extraction of 0, Ga and n are simultaneously extracted, and Ga f IPE (isopropyl ether) can be used to separate and recover Ga f and n can be separated and recovered with TBP. In this Ga1n recovery method, about 200 ppm of solvent is mixed into the raffinate during solvent extraction with Versatic 10E. This example was carried out for the purpose of recovering this solvent.

For testing, Versatic 10 f 254 ppm
Take the rough fibre (pH 3,0) containing 'z
Versatic 10? CC including 1%, 5th section, 10th section
Versatic 10 in rough
The concentration was quantitatively analyzed by Getaromatochography. The results are shown in Table 4.

As shown in Table 4, it is clear that VersatiCl
It can be seen that the rough particles containing 254 ppm of o'z were substantially dispersed and removed. After this scrubbing, the cleaning solution was distilled in the same manner as in Example 1 to add pure CCL and a high concentration of Versatic 10F.
It can be recovered.

[Brief explanation of the drawing]

Fig. 1 is a process diagram showing a general application example of the method of the present invention, Fig. 2 is a process diagram showing an example of applying the solvent extraction raffinate of the gold copper electrolyte of the present invention, and Fig. 6 is a process diagram showing an example of applying the method of the present invention to solvent extraction raffinate. 014'i is a raw bottom velocity diagram of the produced fraction (0014) when distilled at atmospheric pressure. Issue 2 (Kuminto Tadao Nagai Procedural Amendment (Voluntary) 6゜14th month of 1982 (1) Commissioner of the Japan Patent Office
Kazuo Wakasugi (1) 1. Indication of the incident 1982 Patent Application No. 1784.32
(2) 3. Relationship with the case of the person making the amendment Patent applicant (4) (2゜4, Agent 〒162 (1) Column for detailed explanation of the invention in the specification Contents of the amendment Detailed explanation of the invention will be corrected as follows. In the first line of page 10 of the statement, "(B) is" will be replaced with "(B),"
will be corrected. Correct "Residual (1)" in the first row of Table 3 on page 11 of the specification to "Residual oil (1)". "Copper electrolyte" in the 6th line from the bottom of page 11 of the specification is "copper electrolyte"
will be corrected. 1 Correct "dispersion removal" in the 5th line from the bottom of page 15 of the specification to "separation removal". ) The brief description of the drawing has been corrected as follows. 1m CC of 1-ccl on page 14, line 6 of the specification
Correct 14100 mA to .

Claims (4)

[Claims] (1) Rough-fit and/or back-extracted liquid after carrying out the vehicle extraction method? 1. A method for separating solvents in rough tissue and/or a back extract comprising washing with carbon tetrachloride. (2) A method for separating a solvent in a rough extract and/or back extract according to claim 1, which is an extraction method using TBP as a solvent. (3) Versat'ic 1 as solvent extraction en solvent
0? The extraction method used is a method for separating a solvent in a raffinate process/or back extraction solution according to claim 1. (4) After carrying out all the solvent extraction methods, the raffinate is washed with carbon tetrachloride, and the solvent-containing carbon tetrachloride obtained by this washing process is distilled under normal pressure and reduced pressure. FP: Solvent separation in raffinate and/or reverse extract, which consists of separating the solvent and carbon tetrachloride and using it repeatedly.