GB2100709A - Process for recovery of metals from aqueous solutions and suspensions - Google Patents
Process for recovery of metals from aqueous solutions and suspensions Download PDFInfo
- Publication number
- GB2100709A GB2100709A GB08120134A GB8120134A GB2100709A GB 2100709 A GB2100709 A GB 2100709A GB 08120134 A GB08120134 A GB 08120134A GB 8120134 A GB8120134 A GB 8120134A GB 2100709 A GB2100709 A GB 2100709A
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- Prior art keywords
- carrier
- copolymer
- porous
- solution
- extracting agent
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G7/00—Compounds of gold
- C01G7/003—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
- C22B3/22—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition
- C22B3/24—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition by adsorption on solid substances, e.g. by extraction with solid resins
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G37/00—Compounds of chromium
- C01G37/003—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G39/00—Compounds of molybdenum
- C01G39/003—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G5/00—Compounds of silver
- C01G5/003—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The process comprises extraction of metals from aqueous solutions and suspensions by means of an extracting agent (eg. trialkylamines, tributyl phosphate) incorporated into a granulated porous carrier which is a porous copolymer of styrene and 20 to 40% by weight of divinylbenzene with an average pore diameter of from 100 to 500 ANGSTROM containing hydrophilic functional groups in an amount of from 0.15 to 0.5 mg-equiv/g of the carrier.
Description
SPECIFICATION
Process for recovery of metals from aqueous solutions and supensions
The present invention relates to hydrometallurgy and, more specifically, to a process for recovering metals from aqueous solutions and suspensions and can be useful for recovery of valuable metals from ore suspensions, spent solutions of electrolytes, washing liquors,etching solutions, and the like.
In the process for recovering metals from aqueous solutions and suspensions by way of extraction thereof with an extraction agent incorporated in a granulated porous carrier, in accordance with the present invention as the carrier use is made of a porous copolymer of styrene and 20 to 40% by weight of divinylbenzene with an average diameter of pores from 100 to 500 , containing hydrophilic functional groups in an amount of from 0.15 to 0.5 mgequiv./g of the carrier.
To remove the film of the organic phase from the external surfaces of granules, it is advisable that prior to extraction the carrier saturated with an extraction agent should be washed with an alkaline solution having a pH of from 10 to 1 4.
The process for recovering metals according to the present invention is performed by extraction of a metal with an extracting agent incorporated into a porous granulated hydrophobic carrier based on cross-linked network polymer (a copolymer of styrene and 20 to 40% by weight of divinylbenzene) with an average diameter of pores from 100 to 500 A, wherein peripheral surfaces of pores possess hydrophilic properties (for example, due to grafting of functional groups: -HSO3, -H2PO3, nitro and others in an amount of from 0.15 to 0.5 mgequiv/g of the carrier). Prior to indroduction into the suspension the impregnated granules are treated with an aqueous alkaline solution having a pH of from 10 to 14.
The hydrophobic core of the granules is well wetted by solutions of extraction agents immiscible or sparingly miscible with water; therefore the extracting agent is strongly held inside the granuules upon contact with aqueous media. The hydrophilic outer surface of granules of the porous carrier is preferably wetted with water, this making it possible, after the impregnation of the carrier with the extrating agent solution to remove the film of the organic phase from the outer surface of granules in a rather simple way by treatment thereof with an alkaline solution having a pH of from 10 to 14.An increase in the amount of functional groups over 0.5 mgequiv/g results in a noticeable reduction of the amount of the extracting agent retained in the pores of the carrier, and, hence, in an impairment of the extraction process characteristics while a reduction of the amount of functional groups to less than 0.15 mg-equiv/g makes the washing off of the extracting agent film from the surface of granules more difficult.
The extracting agent separated in the washing can be captured and reused. The application of a porous hydrophobic carrier with hydrophilized peripheral pore surfaces in the process of extraction as a carrier of the extracting agent makes it possible to diminish losses of the extracting agent, caused by the removal of the organic phase film from the granule surface, and preclude clogging of the carrier granules in aqueous media.
The process of synthesis of the copolymer of styrene and divinylbenzene makes it possible to obtain a carrier with a prescribed particle size distribution and a narrow pore size range within the required limits. In this aspect. the problem of elimination of the carrier pore clogging with solid suspensions is solved by the use, as the extracting agent carrier, of a porous copolymer of styrene and divinylbenzene (20-40% by weight) with an average diameter of pores within the range of from 100 to 500 A. In this case the carrier pore size is substantially smaller than the size of suspended particles. A reduction of the average pore diameter to less than 100 A has an adverse effect on the rate of absorption of the valuable metal, while an increase of the average pore diameter to over 500 A causes greater clogging of the pores with suspended solid matter.
The porous copolymer of styrene with divinylbenzene is readily available (being an intermediate in the synthesis of a number of ion-exchange resins).
The copolymer of styrene and divinylbenzene has a three-dimensional network structure which precludes its dissolution in the extracting agent and ensures a high mechanical strength of the carrier even if molecules of the extracting agent and of the diluent penetrate into the polymer structure. The use, as the carrier, of a copolymer of styrene and 20 to 40% by weight of divinylbenzene ensures a high mechanical strength of the carrier, its resistance to attrition during recovery of metals from suspensions and increases porosity of a sample, i.e. the amount of the extraction agent retained by the carrier. This allows diminishing a single charge of the carrier in the extraction process and reducing the volume of the employed equipment.To support the above characteristics, given hereinbelow are the data on testing the volume of the retained extraction agent by the carrier employed in the process according to the present invention and on the mechanical strength of the impregnated carrier in comparision with such well-known carriers as porous polyethylene and foamed polyurethane, as well as with a copolymer of styrene and 10% by weight of divinylbenzene. The testing data are shown in Table 1. Porous carriers were impregnated with a 50% solution of trialkylamine in tetrachloroethylene.
Table 1
Volume of the Mechanical
retained ex- strength of the
tracting agent, impregnated car
Carrier % by volume of rier, %
the impregna-ted carrier
Porous polyethylene 50 79.2
Foamed polyurethane 10 72.8
Porous copolymer of styrene and 10% by weight of divinylbenzene 55 96.1
Porous copolymer of styrene and 20% by weight of divinylbenzene 62 98.0
Porous copolymer of styrene and 30% by weight of divinylbenzene 68 98.7
Porous copolymer of styrene and 40% by weight of divinylbenzene 70 98.9
The process for recovering metals according to the present invention has the following advantages over the prior art processes:: it ensures reduced losses of the extraction agent in the operation of recovery of metals due to entrainment of the organic phase by hydrophobic surfaces of granules of the porous carrier during its impregnation, as well as losses caused by attraction of the impregnated carrier; it ensures an increased amount of the extracting agent retained by the porous carrier and saturation of the impregnated granules with the recovered metal, thus lowering the single charge of the carrier, as well as the volume of the equipment employed; it improves the hydrodynamic characteristics of the absorbent layer and, consequently, characteristics of recovery of metals owing to a reduced clogging of granules of the impregnated carrier;; it provides a possibility for repeated use of the carrier due to the elimination of clogging of the carrier pores with solid particles of the suspension; it ensures stable hydrophilic properties of the peripheral surface of grains of the impregnated carrier during a long-time service thereof in the extraction process.
For a better understanding of the present inveniion some specific examples illustrating the process for recovering metals from aqueous solutions and suspension are given hereinbelow.
Example 1
Gold is recovered from spent solutions of electrolytes.
A spent citrate solution of electrolyte discharged from a gold-plating bath has the following composition, g/l: gold, 3.65: citric acid, 210; pH = 4.72; solid suspensions, 50 g/l. Filtration of this solution involves considerabie difficulties and fails to provide the purity of the filtrate required for processing the solution by liquid extraction under conventional conditions of emulsifications of immiscible phases without the formation of a stable emulsion.
Recovery of gold is carried out by means of a 50% solution of a trialkylamine (based on alcohols of the fraction C,-Cg) in tetrachloroethylene. As the carrier for the organic phase use is made of a porous granulated copolymer of styrene with 20% of divinylbenzene with the average pore diameter of 490 A and granule size of from 1.6 to 0.8 mm. Peripheral surfaces of the pores of the copolymer granules contain ionic hydrophilic groups -HSO3 in the amount of 0.2 mg-equiv/g of the copolymer.
These granules of the carrier in the amount of 0.5 kg in the air-dry state are impregnated with a solution of the trialkylamine, the excess of the extracting agent is filtered-off, the impregnated granules are washed with a solution of NH4OH with pH = 11.2. There are obtained 1.35 kg of the extractant-impregnated porous copolymer of styrene with divinylbenzene and from peripheral surfaces of granules there are washed-off 70 g of the solution of the extracting agent (4.9% by the total weight of granules). This solutiion of the extraction agent is repeatedly used for impregnating next portions of the carrier.
In order to recover gold, granules of the porous carrier impregnated with the extracting agent are charged into two columns 0.5-litre capacity each (0.36 kg of the impregnated copolymer).
The electrolyte is passed through the columns from top downwards without any preliminary filtration at the rate of 1.0 I/hr. After saturation of the extracting agent with gold in the first column the latter is switched off, washed with water to remove solid particles, and reextracted with an alkaline cyanide solution (KOH = 10 g/l; CN - = 11 g/l). The supply rate of the reextracted solution into the column is 0.5 I/hr. The recovery of gold into the extracting agent is 99.8%, saturation of the impregnated copolymer with gold is 11 % by weight. The presence of solid particles in the electrolyte does not hinder the extraction process; no clogging of the carrier pores is observed in its repeated use. The content of gold in the effluent re-extract is 30 g/l.
The resulting re-extract is directly used for the preparation of a fresh electrolyte. Losses of the extraction agent during recovery of gold from the electrolyte are insignificant and caused mainly by physical solubility of trialkylamine in the aqueous phase of the suspension (about 0.01 g/l of the electrolyte).
Example 2
Silver is recovered from cyanide solutions.
The starting solution is a mixture of a spent silver-plating electrolyte with washing waters. The solution has the following composition, g/l: silver 7.53; CN', aboout 30.0; pH = 11.6; solid suspension particles, 5 g/l.
The recovery of silver is effected by means of a 50 vol.% solution of a trialkylamine (prepared on the basis of alcohols of the fraction C7-C9) in tetrachloroethylene. As the carrier for the extracting agent use is made of a porous granulated copolymer of styrene with 20% by weight of divinylbenzene. The carrier has the following characteristics: average pore diameter about 200 A, granule size 1.6 + 0.8 mm. The amount of ionic hydrophilic groups -SO3H on the peripheral pore surfaces is 0.25 mg-equiv/g of the copolymer.
The copolymer granules in the amount of 0.5 kg in the air-dry state are poured with 50% solution of the trialkylamine in tetrachloroethylene and maintained until a complete swelling.
Thereafter the excessive amount of the extracting agent is removed by filtration. The impregnated granules are washed with a solution of NH4OH having pH = 11.2. There are obtained 1.20 kg of the porous copolymer impregnated with the extracting agent. 72 g of the extracting agent solution are removed from the granule surface by washing.
The impregnated granules are charged, for the recovery of silver, into two columns by 0.5 litre in each (0.32 kg). The starting solutions pH is preliminarily corrected to 4.5. An aqueous silver-containing solution is successively passed downwardly through the columns at the rate of 1.0 I/hr. After saturation of the extracting agent with silver in the first column it is switched off, washed with water to remove the entrained solid particles and re-extraction is effected with an alkaline cyanide solution of the following composition, g/l: caustic potash, 30.0, CN', 20.0.
The rate of supply of the re-extracting solution into the column is 0.5 I/hr. The recovery of silver into the extracting agent is substantially 100%. The saturation of the impregnated copolymer with silver is 11.5% by weight. Upon re-extraction of silver under the abovementioned conditions with the use of return re-extracting solution a commercial re-extract is obtained which contains 32 g/l of silver in the form of an alkaline solution of potassium dicyanoargentate. The re-extract is used for the preparation of a fresh electrolyte. The extracting agent during operation is lost mainly due to its dissolution in the aqueous solution contacting therewith. The rate of consumption of the extracting agent is found equal to about 8 mg per litre of the processed solution.In contrast to the recovery of silver (and gold as well) on standard ion-exchange resins, the process according to the present invention makes it possible to obtain, in a single stage extraction-reextraction, a concentrated and purified solution of noble metals suitable for correction of electrolytes in electroplating.
Example 3
Chromium is recovered from waste waters of chrome-plating.
The process waters from the chrome-plating section have the following composition, g/l: chromium (IV), 0.101-0.133; chromium (Ill)--none; iron (total), 0.17; sulphate, 0.09; pH is 3.
For the recovery of chromium from this solution use is made of a 50 vol.% solution of a trialkylamine (prepared from alcohols of the fraction C7-Cg) in tetrachlorethylene introduced into a porous granulated copolymer of styrene with 20% by weight of divinylbenzene. The copolymer has the following characteristics: average pore diameter about 200 , granule sized 1.6 + 0.63 mm. The amount of ionic hydrophilic groups -SO3H on the peripheral pore surfaces is 0.2 mg-equiv/g of the copolymer.
In order to prepare the impregnate, the porous copolymer granules in the amount of 0.5 kg in the air-dry state are placed into the above-mentioned solution of the extracting agent and kept till complete swelling. The excess of the extracting agent not absorbed in the pores is separated on filter. The impregnate is washed with a solution of NH40H having pH = 11.2. There is obtained 1.25 kg of the porous copolymer impregnated with the extracting agent. From the granule surface there are washed 70 g of the extracting agent solution.
The recovery of chromium is carried out in two series-connected columns packed with 0.5 litre (0.32 kg) of the impregnate each. The triallylamine is preliminarily converted to the sulphate form by treating the impregnate with a solution of sulphuric acid.
Chromium-containing process waters are passed through the columns downwardly at the rate of 2 I/hr. After saturation of the extracting agent with chromium in the first column, it is disengaged and washed with water. The residual content of chromium in the process water at the outlet of the tail column is below 0.5 mg/l. which corresponds to the degree of recovery of 99.5%. The impregnate saturation with chromium is 11 g/l. For re-extraction of chromium use is made of an alkaline solution of caustic soda with the concentration of 20 g/l.
The solution is fed into the column at the rate of 0.3 I/hr. In the case of using the return solution for the re-extraction the head fraction of the re-extract is obtained with a content of chromium of up to 20 g/l in the form of an alkaline solution of sodium chromate. After acidification of an alkaline solution of sodium chromate. After acidfication the re-extract can be employed for the preparation of electrolyte in the electroplating. The rate of consumption of the extracting agent in the recovery of chromium is about 10 mg per litre of the process solution passed through the columns.
Example 4
Molybdenum is recovered from an ore suspension. The liquid phase of the suspension has the following composition, g/l: molybdenum, 4.4. nitric acid, 31.0, nitrate, 50.0. The amount of the solid phase is 30%. The recovery of molybdenum is effected in parallel on the carrier according to the present invention, i.e. a porous copolymer of styrene with divinylbenzene and on conventional carriers, i.e. foamed polyurethane and poropolyethylene.
The amount of functional groups -SO3 H on the peripheral surfaces on pores of the coplymer of styrene with divinylbenzene is 0.1 5 to 0.3 mg-equiv/g of the copolymer.
The carriers based on the porous polyethylene and foamed polyurethane have a hydrophobic outer surface of the granules. The average pore diameter of samples of porous polyethylene is above 100 yam; that of porous polyethylene is 50 to 100 jtm. The average pore diameter of samples of the copolymer of styrene with divinylbenzene is 100 to 300
As the extracting agent use is made of tributylphosphate. The saturation of impregnates with molybdenum is effected under static conditions at the ratio volumes of the carrier and the aqueous solution of 1:500. The comparative data are shown in Table 2.
Table 2
Amount of the Equilibrium
retained tri- saturation of
No. Carrier butyl phospha- the impregnated
te, kg/l of the carrier with
impregnated car- molybdenum, g/I rier 1. Porous polyethylene 0.49 1 8.2 2. Foamed polyurethane 0.10 4.0 3. Porous copolymer of
styrene and 10% of divinylbenzene 0.54 21.2 4. Porous copolymer of sty
rene and 20% by
weight of divinylbenzene 0.61 23.0 5. Porous copolymmer of sty
rene and 30% by weight
of divinylbenzene 0.66 24.9 6. Porous copolymer of sty
rene and 40% by weight
of divinylbenzene 0.68 26.0
Washing of the impregnates after saturation thereof with molybdenum removes slime ore particles from the hydrophilized surfaces of granules of the copolymer of styrene with divinylbenzene. At the same time, a portion of large-size pores of impregnates based on porous polyethylene and foamed polyurethane becomes in this case clogged with fine particles of the ore pulp.
Re-extraction of molybdenum from carriers impregnated with tributylphosphate is effected by treating granules with water.
Claims (3)
1. A process for recovery of metals from aqueous solutions and suspensions comprising extraction of metals with an extracting agent introduced into a granulated porous carrier which is a porous copolymer of styrene and 20 to 40% by weight of divinylbenzene with an average pore diameter of from 100 to 500 A containing hydrophilic functional groups in an amount of from 0.15 to 0.5 mg-equiv/g of the carrier.
2. A process according to Claim 1, wherein prior to extraction the carrier saturated with the extracting agent is washed with an alkaline solution having pH of from 10 to 14.
3. A process according to the foregoing Claims 1 and 2, substantially as disclosed in the Specification and Examples hereinbefore.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08120134A GB2100709B (en) | 1981-06-30 | 1981-06-30 | Process for recovery of metals from aqueous solutions and suspensions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08120134A GB2100709B (en) | 1981-06-30 | 1981-06-30 | Process for recovery of metals from aqueous solutions and suspensions |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2100709A true GB2100709A (en) | 1983-01-06 |
| GB2100709B GB2100709B (en) | 1985-03-13 |
Family
ID=10522897
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08120134A Expired GB2100709B (en) | 1981-06-30 | 1981-06-30 | Process for recovery of metals from aqueous solutions and suspensions |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2100709B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0265356A1 (en) * | 1986-10-24 | 1988-04-27 | Aluminium Pechiney | Extraction of gallium from Bayer solutions using an impregnated adsorbing resin |
| NL1015960C2 (en) * | 2000-08-18 | 2002-02-19 | Akzo Nobel Nv | Use of a granulate for the removal of liquid, gaseous and / or dissolved components from a process stream. |
| CN113019464A (en) * | 2021-03-11 | 2021-06-25 | 哈尔滨工程大学 | Preparation method of spherical SDB hydrophobic carrier with controllable size and Pt/SDB hydrophobic catalyst |
-
1981
- 1981-06-30 GB GB08120134A patent/GB2100709B/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0265356A1 (en) * | 1986-10-24 | 1988-04-27 | Aluminium Pechiney | Extraction of gallium from Bayer solutions using an impregnated adsorbing resin |
| FR2605646A1 (en) * | 1986-10-24 | 1988-04-29 | Pechiney Aluminium | EXTRACTION OF BAYER LIQUEURS GALLIUM USING AN IMPREGNATED ADSORBENT RESIN |
| NL1015960C2 (en) * | 2000-08-18 | 2002-02-19 | Akzo Nobel Nv | Use of a granulate for the removal of liquid, gaseous and / or dissolved components from a process stream. |
| WO2002016029A1 (en) * | 2000-08-18 | 2002-02-28 | Akzo Nobel N.V. | Use of a granulate for the removal of liquid, gaseous and/or dissolved constituents from a process stream |
| US7258796B2 (en) | 2000-08-18 | 2007-08-21 | Brinkhuis Richard Hendrikus Ge | Use of a granulate for the removal of liquid, gaseous and/or dissolved constituents from a process stream |
| CN113019464A (en) * | 2021-03-11 | 2021-06-25 | 哈尔滨工程大学 | Preparation method of spherical SDB hydrophobic carrier with controllable size and Pt/SDB hydrophobic catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2100709B (en) | 1985-03-13 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |