JPS59102826A - Extracting agent for noble metal salt in aqueous phase - Google Patents

Abstract

PURPOSE:To extract a noble metal salt contained in an aqueous solution with improved efficiency, by adding an organic thiophosphoric acid compound as an extracting agent and a specific diluent to the aqueous solution containing the noble metal. CONSTITUTION:O,O-Diisopropyl-S-benzyl thiophosphate which is an organic thiophosphoric acid compound as an extracting agent is added to seawater or waste water from factories to give 0.001-1% concentration for extracting and recovering U in the seawater or Pt or Pd or another noble metal contained in the waste water from the factories. Naphthalene, diphenyl or trichloroacetic acid as a solvent which is a solid at ordinary temperature and becomes a liquid on heating and has improved compatibility with the extracting agent or a hydrocarbon solvent, e.g. kerosene, ligron or light oil, as a diluent in (1:5)-(1:20) ratio based on the extracting agent. The noble metal is transferred to the extracting agent and further to the diluent, separated from the residual waste water and extracted and recovered with improved efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extractant that efficiently extracts all of the noble metals present in aqueous salt solutions or colloids in an aqueous phase.
All characteristics for use in pendyl thiophonufate.

Various methods have been proposed for collecting uranium in seawater and recovering precious metals such as gold, silver, copper, and mercury in ice water at factories, such as those using a chelate mechanism, ion exchange methods, and even adsorption methods. The present inventors have developed a new extraction method using a mixture of neutral organic phosphorus compounds, β-diketone metals, etc. as extractants and a petroleum-based diluent to completely dissolve and dilute them. We have conducted repeated research on collecting colloidal particles in water and have already made many proposals. An example J thereof is the crab disclosed in JP-A-55-147104. In researching these series of neutral organic phosphorus metals, we used 0,0-diisofuropyl-S-benzylthiophosphate prepared with an organic thiophosphoric acid compound.
In particular, Ag (IJ) exhibits unique behavior and is completely ineffective with conventional organic phosphorus compounds.

0u(IJ showed all the extraction ability, and Au(l
It), Hg (If), Pt (1), Pd (It, l), the neutral organic phosphorus compound TOF proposed so far
It was discovered that it has an excellent extraction ability comparable to that of O (trioctylphosphon oxide) and industrially used thioate μ, and subsequent research revealed that platinum and palladium can also be efficiently extracted. was found experimentally.

The extractant of the present invention, 0,0-diisopropylp-S-benzylthio7os7a1- (hereinafter abbreviated as IBP), is a compound represented by the following molecular formula, and IBP is effective in controlling rice blast disease. Although it is known as a pesticide, there have been no reports of its use as a metal extractant.

When examining the extraction and separation effect of IBPO gold, silver, copper, mercury, platinum, palladium, etc., it has been carried out in combination with various diluents useful for extraction and separation of metals such as uranium. We compared and contrasted several types of neutral organic phosphorus compounds that have been shown to be effective on uranium.

Useful diluents for IBP include triclo/l'l
i[, naphthalene, diphenyl, benzophenone, 1.
3-s) Chlornaphthalene, 2,6-dimethylnaphthalene, P-dichlorobenzene, Rurui, and mixtures of these with kerosene, ligroin, light oil, cyclohexane, etc. Other aromatic compounds, higher alcohols, higher fatty acids, paraffin, beeswax, etc. may also be useful. Particularly preferred diluents are solid heat-soluble solvents that are solid at room temperature, become liquid when heated, and have good compatibility with the extractant, such as naphthalene or a mixture of naphthalene and diphenyl. TFC, kerosene as a liquid diluent, ligroin, light oil, etc. are also significantly effective when used in combination with IBP. In particular, as shown in this S example, Pt(l), Pd
(1, + When kerosene was used as a diluent for IBP for total extraction, it was found that the extraction rate was 10 to 30% higher than that of diphenyl. This indicates that the combination of extractant IBP and diluent Improving the extraction rate (because it is possible, cheap kerosene can be used for Pt(1), Pd(II)
) is extremely important in the extraction of expensive metals.

Since the IBP used here is a so-called solvation solvent that serves as an extractant and a diluent for the metal salt, it can be extracted alone without any other diluent. In this case, the phase separation property is poor, so in order to separate the extracted layer in a short time, it is necessary to filter it through fine powder such as activated carbon, silica gel, alumina, ion exchange resin, a mixture of diphenyl μ and naphthalene, etc. It is recommended that these fine powders be added to the whole aqueous phase and stirred to create a masterpiece of adsorption of IBM2.

Further, sufficient extraction can also be achieved by passing the metal salt aqueous solution in contact with a layer in which IBP has been previously adsorbed on activated carbon alone or together with a diluent.

The various operations of the extraction and separation method using the extractant of the present invention are as follows.

IBP as an extractant and a conventionally used neutral organic phosphorus compound are appropriately added to an aqueous solution containing salts of noble metals such as platinum and palladium, or colloidal particles thereof, and then a diluent is added. Also.

A mixture of an extractant and a diluent may be added in advance. If the diluent is solid at room temperature, the extractant containing the noble metal salts will migrate into the diluent by heating it to a melting state and shaking it for an appropriate period of time. After that, when cooled to around room temperature, the diluent solidifies while containing the extractant, precious metal salts, etc.
This is possible because it can be easily separated from water by filtration or centrifugation. Of course, if the diluent is liquid at room temperature, a sufficient IBP extraction ability can be obtained even if the number of diluents is b.

The amount of IBP added depends on the concentration of the noble metal salt in the aqueous solution, but is usually in the range of 0.001 to 1% of the aqueous solution, and the amount used is very small. Further, the mixing ratio of IBP and diluent is selected in the range of about 1:5 to 1:20 depending on the usage conditions. However, when the concentration is low, the extracted layer does not separate from water, so add activated carbon or silica gel to separate the layers.
For the extraction layer, the extraction layer is adsorbed on activated carbon or silica gel in advance, and extraction is performed using the extraction layer on the surface of the carrier. Platinum and palladium are expensive precious metals and are currently used as catalysts for various reactions, and the IBP extractant of the present invention is of practical use in the recovery of waste catalysts and other precious metals. βru.

In addition, fenitrothion [chemical name: 0,0-dimethy/l/-〇-(3-methy/l/
-4-nitrophenyl laphosfluorothioate, black market name: Sumithion], which is similar to IBP.
IBP was tested in parallel with IBP because it contains phosphoric acid compounds containing 186, but the extraction ability for platinum and palladium is better than that of IBP!
ll was also found to be low.0 The effects of the IBP of the present invention will be specifically explained below with reference to Examples.

Example I Extraction of platinum(II) from hydrochloric and nitric acid solutions by IBP.

4 20ml of 10M platinum (IL) solution, IBPo, 4gK
Using an extract to which 1.69 k of diphenylene was added as a diluent, extraction was performed for 1 minute at a temperature of 20° C. with stirring.

After extraction, the concentration of platinum remaining in the aqueous phase was determined by spectrophotometry using tin chloride, and the extraction rate was determined from the difference from the initial concentration. For comparison of extraction rates, we used the conventionally used neutral organic phosphorus compound TOPO ()! J octi p phoonuphine oxide and industrially used thioate/l
/'i used. The results are shown in Table 1.

It is clear from Table 1 that IBP exhibits better extraction ability than conventional TOPO and thioethers for both hydrochloric acid and nitric acid systems.

Example 2 Extraction of palladium (I) from hydrochloric, nitric, and sulfuric acid solutions using IBP.

Add I to 20 ml of IQ-5M palladium(ll) solution.
Add 2.1 g of BPQ, 9f and a mixture (3:1) of diphenyl and naphthalene as a solid solvent, and add each solution of hydrochloric acid, nitric acid, or sulfuric acid to 0.5 M, 1.6 M, and 12.0 M under stirring at a temperature of 50°C. The entire extraction was performed for 1 minute. After extraction,
The concentration of palladium (CM) remaining in the aqueous phase was determined by nitrophenylamine spectrophotometry, and the extraction rate was determined from the difference from the initial concentration. TOPO and thioate/V used for comparison were the same as in Example 1.

The results are shown in Table 2.

$2 table In the case of palladium (Il), especially in nitric acid and sulfuric acid systems, IB
The effect of P is large.

Example 3 In Example 2, palladium CM) solution 20ml KI
BP0.9F and 2 ml of kerosene as a liquid solvent were added and extracted with stirring at room temperature for 1 minute. The concentration of palladium (CM) remaining in the aqueous phase after extraction was determined by nitrophenyamine spectrophotometry to determine the extraction rate. 'l used for comparison
'OPO and thioetep are the same as in Example 1. The results are shown in Table 3.

Table 3 Even when kerosene was used as a diluent, better results were obtained with IBP than with TOPO and thioether.

that's all Applicant Yasumasa Shigetomi Kumiai Chemical Industry Co., Ltd. Agent: Benri Dokun Hirosanbe

Claims (1)

[Claims] 1. 0,〇-diisopropyl- which is used alone or together with a diluent as an extractant when extracting and separating an aqueous solution or colloidal particles of a precious metal salt such as platinum or palladium present in an aqueous phase.
Extractant of noble metal salts in aqueous phase with 8-pendylthiophonuphatate. 2. The extractant according to claim 1, wherein the diluent is a room temperature solid heating soluble bath such as diphenyl-naphthalene or trichloroacetic acid. 3. The extractant according to claim 1, wherein the diluent is a hydrogenated solvent such as kerosene, ligroin, or light oil.