EP0188561A1 - Extraction of metal values from aqueous liquids - Google Patents
Extraction of metal values from aqueous liquidsInfo
- Publication number
- EP0188561A1 EP0188561A1 EP85903673A EP85903673A EP0188561A1 EP 0188561 A1 EP0188561 A1 EP 0188561A1 EP 85903673 A EP85903673 A EP 85903673A EP 85903673 A EP85903673 A EP 85903673A EP 0188561 A1 EP0188561 A1 EP 0188561A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cell walls
- metal values
- extraction
- extraction medium
- aqueous
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- 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
- C22B3/18—Extraction of metal compounds from ores or concentrates by wet processes with the aid of microorganisms or enzymes, e.g. bacteria or algae
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/90—Investigating the presence of flaws or contamination in a container or its contents
-
- 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
Definitions
- the present invention is concerned with a method of extracting metal values from aqueous liquids.
- aqueous effluents it is desirable, and sometimes ma ⁇ datory j to extract toxic or radioactive metals (such as cadmium, lead, arsenic, uranium, plutonium or other radi ⁇ nuclides) from aqueous effluents before the latter can be discharged into, for example, a river or a stream.
- toxic or radioactive metals such as cadmium, lead, arsenic, uranium, plutonium or other radi ⁇ nuclides
- metal values present in an aqueous liquid are commercially valu ⁇ able (for example, when the metal values are of noble metals such as gold, silver or platinum); it is desirable to extract and recover such metals from the aqueous liquid.
- Various methods are known for extracting metal values from aqueous liquids; for example, by treatment with an ion-exchange resin or by the use of live microorganisms. We have now discovered that non-viable cell walls are effective for the extraction of metal values from aqueous liquids.
- a method of processing an aqueous liquid containing metal values which comprises contacting the - aqueous liquid with an extraction medium comprising non- viable cell walls so as to cause said metal values to complex with said cell walls, and separating said complexed cell walls from the aqueous liquid.
- the metal values are preferably separated from the complexed cell walls, for example, by desorption under acid conditions, by electrolysis, or by dest ⁇ ruction of the extraction medium ( for ' example, by , pyrolysis or burning).
- the cell walls used in the method accord- ing to the invention are either dead or, if still alive, non-viable; there may be present with the contents of- the cells or, preferably, substantially free of the former contents of the cells.
- the cell walls are pref ⁇ erably broken up and dead; nevertheless, it may be possible to carry out the method according to the invention in the presence of a small amount of living cells in addition to the dead material.
- the cell walls are preferably those of micro ⁇ organisms or plants; suitable microorganisms are Saccharomyces yeasts (for example, Saccharomyces c erevisiae or uvarum) .
- suitable microorganisms are those grown commercially for the production of pharm ⁇ aceutical materials or precursors therefor; examples of such materials are filamentary fungi such as Penicillium fungi.
- waste material available in the commercial product ⁇ ion o f yeast extract is eminently suitable for use in the method according to the invention.
- the method according to the invention is preferably carried out in a - reaction vessel and it may be carried out as a continuous process, a semi-continu ⁇ ous process or a batch process.
- the vessel is preferably a column or fluidized bed of elongated shape, with an inlet at or near one end of an outlet at " or near the other end thereof.
- the vessel is preferably disposed with its greatest length upright or inclined to the
- the extraction medium may comprise a flocculent mass comprising the cell walls treated with polyvalent ions, for example, non-deleterious cations such as calcium,
- T5 or chelating anions such as borate, phosphate, ethylene diamine tetraacetate (EDTA) or nitrilotriacetate (NTA).
- EDTA ethylene diamine tetraacetate
- NTA nitrilotriacetate
- the extraction medium is in the form of a flocculent mass, it can be immobilised and used in a similar manner to a filter.
- the extraction medium may be in the form of an aqueous slurry, which preferably contains the non- viable cell walls in an amount of 1 to 5?. by weight, based on the weight of the slurry. The proportion may be higher
- the concen ⁇ tration selected depends on the concentration of the metal value to be extracted and on the type of cell walls.
- a slurry When a slurry is used, it may contain a stab ⁇
- the stabilizer is preferably a salt of a non-deleterious cation (such as an alkali metal) and an anion such as azide or sorbate.
- a non-deleterious cation such as an alkali metal
- an anion such as azide or sorbate.
- suitable such stabilizers are sodium or potassium
- Another possible class of stabilizers are organic acids, such as sorbic acid.
- the slurry may be housed in a reaction vessel which is preferably of elongate shape, and is preferably disposed with its greatest length upright or inclined
- the horizontal there is preferably an inlet at or near the bottom and an outlet at or near the top thereof. ciruugh the inlet, intermittently or continuously, and liquid is withdrawn from the outlet. The flow rate is sufficiently slow for the removal of cell wall material with the -liquid leaving through the outlet at least partially restrained by gravity. Nevertheless, if desired ⁇ the contents of the vessel may be stirred.
- t.he vessel is charged with slurry and is used for a pe iod without any additional extraction medium being introduced.
- more extraction medium is introduced during the process.
- the medium may be added to the aqueous solut ⁇ ion or suspension shortly before it is introduced into the vessel.
- the solution or suspension may remain in contact with the extraction medium for any suitable period of time, but the period may be at leastiDne hour and. may be several hours in duration.
- a typical timescale is 1 to 5 hours (depending on the particular extraction process).
- the liquid leaving the vessel is likely to contain quantities of solid material, much or all of which may comprise the extraction medium.
- the solid material may be removed in any suitable manner.
- highly dispersed material such as the walls of dead yeast cells
- it may be necessary to separate the solids from the liquids by a centrifug- ing process but in the case of coarser material it may be possible to separate the solids by filtration; for example, use may be made of vibrating screens.
- the cell walls may be treated in " such a manner that they tend to aggregate or floccu ⁇ late. This treatment may be carried out before extraction of metal values in the method according to the invention , for example, by treatment with polyvalent, ions as described above.
- Flocculation may-als ⁇ be carried during or after extraction of metal values; for example, by treatment with polyvalent ions or a particulate ion exchange resin.
- Ibis ⁇ ead cell walls may be treated wit 'an amide.
- the invention may be of use in removing cadmium ions from effluents from processes carried out in the steel and nickel industries, and in removing gold, platinum and silver from industrial effluents from a wide variety of processes such as certain processes carried out in the ceramic or plating industries.
- the invention may also be used in removing radioactive metals such as uranium and pluton- iu or other radionuclides from effluents containing such metals.
- radioactive metals such as uranium and pluton- iu or other radionuclides
- the metal values extracted in the method according to the invention are preferably initially present in the form of simple hydrated ions, although they may be present in other ionic species.
- the aqueous liquid being treated by the method according to the invention is generally a solution or suspension in water.
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biochemistry (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Microbiology (AREA)
- Materials Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Manufacturing & Machinery (AREA)
- Biotechnology (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Removal Of Specific Substances (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Treatment Of Water By Ion Exchange (AREA)
Abstract
Des métaux (généralement sous forme d'ions) sont extraits de solutions ou suspensions aqueuses à l'aide d'un milieu d'extraction composé de parois cellulaires non viables (p.ex. des déchets provenant de la production d'extraits de levure), qui forment des complexes avec les métaux. Les parois cellulaires ayant formé les complexes sont ensuite séparées de la solution ou suspension aqueuse. Le milieu d'extraction peut se présenter sous forme d'une boue ou d'une masse de floculants comprenant les parois cellulaires, traitées à l'aide d'un agent de chélation. Cette méthode peut être utilisée pour l'extraction de métaux nobles, ou de métaux toxiques ou radioactifs.Metals (usually in the form of ions) are extracted from aqueous solutions or suspensions using an extraction medium composed of non-viable cell walls (eg waste from the production of yeast extracts ), which form complexes with metals. The cell walls which formed the complexes are then separated from the aqueous solution or suspension. The extraction medium may be in the form of a slurry or a mass of flocculants comprising the cell walls, treated with a chelating agent. This method can be used for the extraction of noble metals, or toxic or radioactive metals.
Description
Extraction of Metal Values from Aqueous Liquids
The present invention is concerned with a method of extracting metal values from aqueous liquids.
Many industrial processes produce as by-products aqueous liquids containing metal values in solution or suspension; it is often desirable, and sometimes essential, for the metal values to be extracted from such aqueous liquids.
For example, it is desirable, and sometimes maπdatoryj to extract toxic or radioactive metals (such as cadmium, lead, arsenic, uranium, plutonium or other radiαnuclides) from aqueous effluents before the latter can be discharged into, for example, a river or a stream. There is, indeed , often a statutory prohibition on the discharge of effluent containing more than a minute con¬ centration of radioactive metal.
There are, of course, cases where the metal values present in an aqueous liquid are commercially valu¬ able (for example, when the metal values are of noble metals such as gold, silver or platinum); it is desirable to extract and recover such metals from the aqueous liquid.
Various methods are known for extracting metal values from aqueous liquids; for example, by treatment with an ion-exchange resin or by the use of live microorganisms. We have now discovered that non-viable cell walls are effective for the extraction of metal values from aqueous liquids.
According to the invention, therefore, there is provided a method of processing an aqueous liquid containing metal values, which comprises contacting the - aqueous liquid with an extraction medium comprising non- viable cell walls so as to cause said metal values to complex with said cell walls, and separating said complexed cell walls from the aqueous liquid.
The metal values are preferably separated from the complexed cell walls, for example, by desorption under acid conditions, by electrolysis, or by dest¬ ruction of the extraction medium ( for' example, by, pyrolysis or burning).
The cell walls used in the method accord- ing to the invention are either dead or, if still alive, non-viable; there may be present with the contents of- the cells or, preferably, substantially free of the former contents of the cells. The cell walls are pref¬ erably broken up and dead; nevertheless, it may be possible to carry out the method according to the invention in the presence of a small amount of living cells in addition to the dead material.
The cell walls are preferably those of micro¬ organisms or plants; suitable microorganisms are Saccharomyces yeasts (for example, Saccharomyces c erevisiae or uvarum) . Other suitable microorganisms are those grown commercially for the production of pharm¬ aceutical materials or precursors therefor; examples of such materials are filamentary fungi such as Penicillium fungi.
Many suitable materials comprising non-viable cell walls are available as waste products; for example, waste material available in the commercial product¬ ion o f yeast extract is eminently suitable for use in the method according to the invention.
The method according to the invention is preferably carried out in a - reaction vessel and it may be carried out as a continuous process, a semi-continu¬ ous process or a batch process. In the case of a continu¬ ous or semi-continuous process the vessel is preferably a column or fluidized bed of elongated shape, with an inlet at or near one end of an outlet at "or near the other end thereof. The vessel is preferably disposed with its greatest length upright or inclined to the
10 horizontal and with its inlet at or near the bottom and its outlet at or near the top.
The extraction medium may comprise a flocculent mass comprising the cell walls treated with polyvalent ions, for example, non-deleterious cations such as calcium,
T5 or chelating anions such as borate, phosphate, ethylene diamine tetraacetate (EDTA) or nitrilotriacetate (NTA). In the case where the extraction medium is in the form of a flocculent mass, it can be immobilised and used in a similar manner to a filter.
20 In an alternative embodiment of the present invention, the extraction medium may be in the form of an aqueous slurry, which preferably contains the non- viable cell walls in an amount of 1 to 5?. by weight, based on the weight of the slurry. The proportion may be higher
25 than 5?ά (for example, when the slurry is concentrated) or lower than 1 % (for example, as low as 0.1 %) . The concen¬ tration selected depends on the concentration of the metal value to be extracted and on the type of cell walls.
When a slurry is used, it may contain a stab¬
30 ilizer to prevent or slow down deterioration of decom¬ position of the cell walls. The stabilizer is preferably a salt of a non-deleterious cation (such as an alkali metal) and an anion such as azide or sorbate. Examples of suitable such stabilizers are sodium or potassium
35 azide or sorbate. Another possible class of stabilizers are organic acids, such as sorbic acid.
The slurry may be housed in a reaction vessel which is preferably of elongate shape, and is preferably disposed with its greatest length upright or inclined
4Q to the horizontal; there is preferably an inlet at or near the bottom and an outlet at or near the top thereof.
ciruugh the inlet, intermittently or continuously, and liquid is withdrawn from the outlet. The flow rate is sufficiently slow for the removal of cell wall material with the -liquid leaving through the outlet at least partially restrained by gravity. Nevertheless, if desired^ the contents of the vessel may be stirred. In one method, t.he vessel is charged with slurry and is used for a pe iod without any additional extraction medium being introduced. In a modified method, however, more extraction medium is introduced during the process. For example, the medium may be added to the aqueous solut¬ ion or suspension shortly before it is introduced into the vessel. The solution or suspension may remain in contact with the extraction medium for any suitable period of time, but the period may be at leastiDne hour and. may be several hours in duration. A typical timescale is 1 to 5 hours (depending on the particular extraction process).
The liquid leaving the vessel is likely to contain quantities of solid material, much or all of which may comprise the extraction medium.
The solid material may be removed in any suitable manner. In the case of highly dispersed material, such as the walls of dead yeast cells, it may be necessary to separate the solids from the liquids by a centrifug- ing process, but in the case of coarser material it may be possible to separate the solids by filtration; for example, use may be made of vibrating screens. In order to simplify the separation of the extraction medium from the liquid the cell walls may be treated in" such a manner that they tend to aggregate or floccu¬ late. This treatment may be carried out before extraction of metal values in the method according to the invention , for example, by treatment with polyvalent, ions as described above. Flocculation may-alsα be carried during or after extraction of metal values; for example, by treatment with polyvalent ions or a particulate ion exchange resin. In an alter¬ native method of inducing aggregation or flocculation,
Ibis αead cell walls may be treated wit 'an amide. The invention may be of use in removing cadmium ions from effluents from processes carried out in the steel and nickel industries, and in removing gold, platinum and silver from industrial effluents from a wide variety of processes such as certain processes carried out in the ceramic or plating industries. The invention may also be used in removing radioactive metals such as uranium and pluton- iu or other radionuclides from effluents containing such metals. For example, there may be a vessel, contain¬ ing the extraction medium, permanently connected in an effluent line so that in the event of an error occurr¬ ing such that radioactive material is inadvertently discharged through the line it automatically under¬ goes treatment in the vessel.
The metal values extracted in the method according to the invention are preferably initially present in the form of simple hydrated ions, although they may be present in other ionic species.
The aqueous liquid being treated by the method according to the invention is generally a solution or suspension in water.
Claims
1. A method of extracting metal values from an aqueous liquid, which comprises contacting said liquid with an extraction medium comprising non-viable cell walls so as to cause at least some of said metal values to complex with said cell walls, and separating said complexed cell walls from the aqueous liquid.
2. A method according to claim , in which said cell walls are substantially free of the former contents of the cells.
3. A method according to claim 1 or 2, in which said cell walls comprise fungal material and/or waste material from yeast extract production.
4. A method according to any of claims 1 to 3, in which said extraction medium is a flocculent mass comprising said cell walls treated with polyvalent ions.
5. A method according to claim 4, in which said polyvalent ions comprise chelating anions.
6. A method according to claim 4 or 5, in which the extract¬ ion medium is employed in a column or a fluidised bed.
7. A method according to any of claims 1 to 3, in which the extraction medium is in the form of an aqueous slurry containing said non-viable cell walls in an amount of 1 to 5?ή by weight.
8. A method according to claim 7, in which the slurry contains a stabilizer, such as an alkali metal azide or sorbate.
9. A method according to any of claims 1 to 8, in which the complexed metal values are separated from said cell walls .
10. A method according to any of claims 1 to 9, in which the metal values are of toxic, radioactive or noble metals.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8418588 | 1984-07-20 | ||
| GB848418588A GB8418588D0 (en) | 1984-07-20 | 1984-07-20 | Removing metals from aqueous solutions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0188561A1 true EP0188561A1 (en) | 1986-07-30 |
Family
ID=10564215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85903673A Withdrawn EP0188561A1 (en) | 1984-07-20 | 1985-07-19 | Extraction of metal values from aqueous liquids |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0188561A1 (en) |
| AU (1) | AU4630785A (en) |
| GB (1) | GB8418588D0 (en) |
| WO (1) | WO1986000935A1 (en) |
| ZA (1) | ZA855450B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4937667A (en) * | 1987-11-09 | 1990-06-26 | Etat Francais Represente Par Le Ministre Delegue Des Postes Et Telecommunications (Centre Nationale D'etudes Des Telecommunications) | Method and apparatus for processing picture signals having interlaced field scanning |
| US8928935B2 (en) | 2004-10-28 | 2015-01-06 | Hewlett-Packard Development Company, L.P. | Color accuracy check |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02118035A (en) * | 1988-10-26 | 1990-05-02 | Ajinomoto Co Inc | Uranium adsorbent |
| US5120441A (en) * | 1990-05-30 | 1992-06-09 | The Regents Of The University Of California | Method for removal of metal atoms from aqueous solution using suspended plant cells |
| IL96611A (en) * | 1990-10-12 | 1995-06-29 | Israel Electric Corp Ltd | Extraction of metal oxides from coal fly ash by microorganisms and a new microorganism useful therefor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4021368A (en) * | 1973-02-12 | 1977-05-03 | Ceskoslovenska Komise Pro Atomovou Energii Praha | Process of treating mycelia of fungi for retention of metals |
| DE2326224C3 (en) * | 1973-05-23 | 1975-11-13 | Kernforschungsanlage Juelich Gmbh, 5170 Juelich | Process for the separation of ionized substances characterized by chemical or physical properties from an aqueous solution |
| US4256485A (en) * | 1979-10-11 | 1981-03-17 | Northwest Ecological Research & Development, Inc. | Enzyme oxidation of sulfides in minerals |
| US4320093A (en) * | 1979-11-13 | 1982-03-16 | Bohumil Volesky | Separation of uranium by biosorption |
| US4293334A (en) * | 1980-02-12 | 1981-10-06 | Engelhard Minerals & Chemicals Corporation | Recovery of metals |
| US4293333A (en) * | 1980-02-12 | 1981-10-06 | Engelhard Minerals & Chemicals Corporation | Microbiological recovery of metals |
-
1984
- 1984-07-20 GB GB848418588A patent/GB8418588D0/en active Pending
-
1985
- 1985-07-19 WO PCT/GB1985/000323 patent/WO1986000935A1/en unknown
- 1985-07-19 AU AU46307/85A patent/AU4630785A/en not_active Abandoned
- 1985-07-19 EP EP85903673A patent/EP0188561A1/en not_active Withdrawn
- 1985-07-19 ZA ZA855450A patent/ZA855450B/en unknown
Non-Patent Citations (1)
| Title |
|---|
| See references of WO8600935A1 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4937667A (en) * | 1987-11-09 | 1990-06-26 | Etat Francais Represente Par Le Ministre Delegue Des Postes Et Telecommunications (Centre Nationale D'etudes Des Telecommunications) | Method and apparatus for processing picture signals having interlaced field scanning |
| US8928935B2 (en) | 2004-10-28 | 2015-01-06 | Hewlett-Packard Development Company, L.P. | Color accuracy check |
Also Published As
| Publication number | Publication date |
|---|---|
| AU4630785A (en) | 1986-02-25 |
| GB8418588D0 (en) | 1984-09-12 |
| ZA855450B (en) | 1986-03-26 |
| WO1986000935A1 (en) | 1986-02-13 |
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| AK | Designated contracting states |
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| 18D | Application deemed to be withdrawn |
Effective date: 19860624 |
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| RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: GREENSHIELDS, RODERICK, NORMAN4 BRYNMEAD COURT |