EP0267170B1 - Treatment of middlings - Google Patents
Treatment of middlings Download PDFInfo
- Publication number
- EP0267170B1 EP0267170B1 EP87850297A EP87850297A EP0267170B1 EP 0267170 B1 EP0267170 B1 EP 0267170B1 EP 87850297 A EP87850297 A EP 87850297A EP 87850297 A EP87850297 A EP 87850297A EP 0267170 B1 EP0267170 B1 EP 0267170B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- middlings
- grinding
- dressing
- reground
- regrinding
- 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.)
- Expired
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
- B02C17/16—Mills in which a fixed container houses stirring means tumbling the charge
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
- B02C17/18—Details
- B02C17/20—Disintegrating members
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
- B03B9/00—General arrangement of separating plant, e.g. flow sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
- B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
- B03D1/00—Flotation
- B03D1/02—Froth-flotation processes
Definitions
- the present invention relates to concentrating or dressing processes within the mineral processing technique, and relates more particularly to a method for use when dressing a mineral product, particularly when dressing iron ore and sulphide ore, which product has been finely divided to a particle size suitable for dressing treatment thereof in at least two stages by flotation or by magnetic separation, wherein middlings obtained during the dressing treatment are reground in order to crush individual half-grains and therewith release valuable mineral therefrom, and wherein the reground middlings are then again subjected to dressing treatment.
- middlings rich in valuable mineral e.g. the waste or tailings deriving from a cleaner of a flotation process or from a secondary magnetic separator
- the middlings may be passed to the ball mill, where they are reground, but it has also been proposed to regrind the middlings in a separate tube mill.
- the object of the present invention is to provide a novel and useful method of procedure which will at least substantially avoid the aforesaid drawbacks encountered with known middlings- regrinding processes.
- This regrinding method effected with the aid of comparatively small grinding bodies, results with only a relatively low energy input, in an effective attrition effect which is directed essentially to the coarse fraction of the middlings, so as to obtain a reground product which can be beneficially returned to the dressing process and which exhibits an optimum, steep particle-distribution curve.
- This regrinding is effected to advantage with an energy input of at most 15 kWh/t of dry middlings, there being normally obtained herewith the desired steep particle-size distribution with desired degradation of the so-called half-grains, i.e. mineral particles which contain both valuable mineral and gangue, without at the same time forming excessive quantities of such fines which are liable to generate not-readily processed sludge or dust in the dressing equipment.
- half-grains i.e. mineral particles which contain both valuable mineral and gangue
- the grinding bodies used when practicing the method according to the present invention may consist of a metallic or a ceramic material, although it is normally preferred to use as grinding medium grinding bodies composed of autogenous material, e.g. a fraction selected from the material to be dressed, or a material which is rich in silicon, such as quartz or olivine. Grinding bodies which are comprised of these preferred materials are much cheaper than prefabricated metallic or ceramic grinding bodies, and result in grinding-medium residues in the reground middlings which are normally quite innocuous to the dressing process, while material which is worn away from, e.g., grinding bodies of steel, on the other hand, may cause metallic coatings to form on mineral grains, therewith rendering the concentration by flotation difficult. Problems caused by the entrainment of grinding-medium residues with the reground material, however, can normally be overcome by subjecting the reground middlings to a separate treatment to remove undesirable grinding-medium residues.
- the middlings can be reground either in a dry or in a wet environment.
- a dressing process which is carried out in a wet environment, such as a flotation concentration process
- an advantage is gained when the middlings are also reground in a wet environment, thereby obviating the need of expensive de-watering treatment.
- References 1 and 2 in the drawing designate respectively a primary mill and a secondary mill, which in the illustrated embodiment are assumed to have the form of a rod mill 1, which receives a crushed mineral product to be dressed or concentrated, and a ball mill 2 for continued grinding of the product arriving from the rod mill 1.
- the product leaving the ball mill 2 is divided in a classifier 3 into a relatively fine-grained fraction, suitable for concentration, and a coarser fraction, which is returned to the ball mill for further reduction in size, in the manner indicated by the line 4.
- the aforesaid fine-grain fraction is passed to a concentration plant, which in the case of the illustrated embodiment is assumed to be a flotation plant that incorporates a rougher 5 and a cleaner 6.
- the fine-grain fraction is supplied in a substantially continual stream to the rougher 5, where the material is subjected to flotation with a suitable reagent, to form a waste or tailings containing only a low proportion of the valuable mineral or minerals concerned, these tailings being removed from the process in the manner indicated by the arrow 7.
- the rougher concentrate obtained in the rougher 5 is passed to the cleaner 6, in the manner indicated by the arrow 8, where there is formed, in a conventional manner, a final concentrate which contains a high proportion of valuable mineral and which is removed from the process in the manner indicated by the arrow 9, and a return product or middlings having a relatively high content of valuable mineral.
- middlings are passed, in the manner indicated by the arrow 10, to a mill 11 which incorporates an agitated grinding medium, by which is meant in this patent application a mill in which a grinding effect is achieved with the aid of grinding bodies and in which the middlings that are being ground are agitated by means of an agitator that moves at a high speed. Grinding is thus accomplished as a result of pressure and shear forces which act between the grinding bodies and the middlings, these forces being generated by the agitator, which is constructed so as normally to rotate at a speed of several hundred revolutions per minute and to deliver a high power output per unit of mill volume, normally in the order of at least 10 times the power consumption per unit of mill volume of a conventional ball mill.
- the drawing shows the mill 11 provided with a rotor 12 having radially extending rotor blades 13 and stator blades 14 extending radially into the grinding chamber from the surrounding mill casing.
- the grinding bodies in the mill 11 comprise a material which is undesirable in the reground middlings
- those fractions of this material which accompany the reground middlings discharged from the mill 11 may be separated out in an optional separation step 15.
- Grinding in the mill 11 is preferably effected in a wet environment.
- the reground product is returned to a suitable location in the rougher 5, for renewed flotation therein, as indicated by the arrow 16.
- the material being dressed may, e.g., be a sulphide ore which is concentrated by separating therefrom gangue or oxidic iron ore which is concentrated by separating phosphorous constituents therefrom.
- the rougher 5 and the cleaner 6 may be replaced with magnetic separators mutually connected in series.
- the grinding medium may comprise grinding bodies, e.g. balls or rods, made of sintered hard metal, such as sintered tungsten carbide.
Abstract
Description
- The present invention relates to concentrating or dressing processes within the mineral processing technique, and relates more particularly to a method for use when dressing a mineral product, particularly when dressing iron ore and sulphide ore, which product has been finely divided to a particle size suitable for dressing treatment thereof in at least two stages by flotation or by magnetic separation, wherein middlings obtained during the dressing treatment are reground in order to crush individual half-grains and therewith release valuable mineral therefrom, and wherein the reground middlings are then again subjected to dressing treatment.
- It is normal practice when dressing mineral products to withdraw from the process so-called middlings rich in valuable mineral, e.g. the waste or tailings deriving from a cleaner of a flotation process or from a secondary magnetic separator, and to regrind these middlings and to return the reground product to the mineral dressing process at some suitable location thereof. If, for instance, the material being dressed is obtained from a series of mills incorporating a rod mill and a downstream-connected ball mill, the middlings may be passed to the ball mill, where they are reground, but it has also been proposed to regrind the middlings in a separate tube mill. Regrinding of the middlings in ball mills and tube mills is a relatively inefficient procedure, both with regard to energy input and with regard to the increase in yield gained. There are obtained flat particle-distribution curves which exhibit an excessively large quantity of not-readily dressed fine fraction, whereas excessively large proportions of the coarse fraction of the middlings pass through the mill without being reduced sufficiently therein.
- The object of the present invention is to provide a novel and useful method of procedure which will at least substantially avoid the aforesaid drawbacks encountered with known middlings- regrinding processes.
- To this end it is proposed in accordance with the invention that when practicing a method of the kind recited in the introduction, the middlings are reground in a manner known per se in a mill containing an agitated grinding medium, to a particle size which is smaller than K80 = 100 pm, with the aid of grinding bodies having a mean size of from 2 to 6 mm. This regrinding method, effected with the aid of comparatively small grinding bodies, results with only a relatively low energy input, in an effective attrition effect which is directed essentially to the coarse fraction of the middlings, so as to obtain a reground product which can be beneficially returned to the dressing process and which exhibits an optimum, steep particle-distribution curve.
- This regrinding is effected to advantage with an energy input of at most 15 kWh/t of dry middlings, there being normally obtained herewith the desired steep particle-size distribution with desired degradation of the so-called half-grains, i.e. mineral particles which contain both valuable mineral and gangue, without at the same time forming excessive quantities of such fines which are liable to generate not-readily processed sludge or dust in the dressing equipment.
- The grinding bodies used when practicing the method according to the present invention may consist of a metallic or a ceramic material, although it is normally preferred to use as grinding medium grinding bodies composed of autogenous material, e.g. a fraction selected from the material to be dressed, or a material which is rich in silicon, such as quartz or olivine. Grinding bodies which are comprised of these preferred materials are much cheaper than prefabricated metallic or ceramic grinding bodies, and result in grinding-medium residues in the reground middlings which are normally quite innocuous to the dressing process, while material which is worn away from, e.g., grinding bodies of steel, on the other hand, may cause metallic coatings to form on mineral grains, therewith rendering the concentration by flotation difficult. Problems caused by the entrainment of grinding-medium residues with the reground material, however, can normally be overcome by subjecting the reground middlings to a separate treatment to remove undesirable grinding-medium residues.
- The middlings can be reground either in a dry or in a wet environment. Particularly when the invention is practiced in a dressing process which is carried out in a wet environment, such as a flotation concentration process, an advantage is gained when the middlings are also reground in a wet environment, thereby obviating the need of expensive de-watering treatment.
- The invention will now be described with reference to the accompanying drawing which illustrates schematically, by way of example only, an embodiment of a plant for carrying out the method according to the invention.
-
References rod mill 1, which receives a crushed mineral product to be dressed or concentrated, and aball mill 2 for continued grinding of the product arriving from therod mill 1. The product leaving theball mill 2 is divided in aclassifier 3 into a relatively fine-grained fraction, suitable for concentration, and a coarser fraction, which is returned to the ball mill for further reduction in size, in the manner indicated by theline 4. The aforesaid fine-grain fraction is passed to a concentration plant, which in the case of the illustrated embodiment is assumed to be a flotation plant that incorporates a rougher 5 and a cleaner 6. The fine-grain fraction is supplied in a substantially continual stream to the rougher 5, where the material is subjected to flotation with a suitable reagent, to form a waste or tailings containing only a low proportion of the valuable mineral or minerals concerned, these tailings being removed from the process in the manner indicated by thearrow 7. The rougher concentrate obtained in the rougher 5 is passed to the cleaner 6, in the manner indicated by thearrow 8, where there is formed, in a conventional manner, a final concentrate which contains a high proportion of valuable mineral and which is removed from the process in the manner indicated by thearrow 9, and a return product or middlings having a relatively high content of valuable mineral. These middlings are passed, in the manner indicated by thearrow 10, to amill 11 which incorporates an agitated grinding medium, by which is meant in this patent application a mill in which a grinding effect is achieved with the aid of grinding bodies and in which the middlings that are being ground are agitated by means of an agitator that moves at a high speed. Grinding is thus accomplished as a result of pressure and shear forces which act between the grinding bodies and the middlings, these forces being generated by the agitator, which is constructed so as normally to rotate at a speed of several hundred revolutions per minute and to deliver a high power output per unit of mill volume, normally in the order of at least 10 times the power consumption per unit of mill volume of a conventional ball mill. Themill 11 operates with relatively small grinding bodies, e.g. bodies having a mean size (diameter) of 2-6 mm and, at moderate resident times with regard to the middlings being reground, will reduce the middlings to a particle size, e.g., of beneath kao = 100 pm, e.g. between k80 = 20 pm and kso = 90 pm, such that so-called half-grains are crushed effectively to free particles of valuable mineral without reducing the middlings to the extreme. - The drawing shows the
mill 11 provided with arotor 12 having radially extendingrotor blades 13 andstator blades 14 extending radially into the grinding chamber from the surrounding mill casing. - When the grinding bodies in the
mill 11 comprise a material which is undesirable in the reground middlings, those fractions of this material which accompany the reground middlings discharged from themill 11 may be separated out in anoptional separation step 15. Grinding in themill 11 is preferably effected in a wet environment. The reground product is returned to a suitable location in the rougher 5, for renewed flotation therein, as indicated by thearrow 16. - The material being dressed may, e.g., be a sulphide ore which is concentrated by separating therefrom gangue or oxidic iron ore which is concentrated by separating phosphorous constituents therefrom. When dressing magnetic ores, the rougher 5 and the cleaner 6 may be replaced with magnetic separators mutually connected in series.
- The grinding medium may comprise grinding bodies, e.g. balls or rods, made of sintered hard metal, such as sintered tungsten carbide.
Claims (6)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT87850297T ATE60527T1 (en) | 1986-10-06 | 1987-10-02 | TREATMENT OF INTERMEDIATE GOODS. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8604241 | 1986-10-06 | ||
SE8604241A SE8604241D0 (en) | 1986-10-06 | 1986-10-06 | RETURN MATERIALS PROCESSING |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0267170A1 EP0267170A1 (en) | 1988-05-11 |
EP0267170B1 true EP0267170B1 (en) | 1991-01-30 |
Family
ID=20365837
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP87850297A Expired EP0267170B1 (en) | 1986-10-06 | 1987-10-02 | Treatment of middlings |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0267170B1 (en) |
AT (1) | ATE60527T1 (en) |
DE (1) | DE3767832D1 (en) |
ES (1) | ES2021395B3 (en) |
SE (1) | SE8604241D0 (en) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1230847B (en) * | 1989-05-22 | 1991-11-08 | Rodio & C Const G | PROCEDURE AND PLANT FOR THE PRODUCTION OF INJECTABLE CEMENT MIXTURES. |
SE9000797L (en) * | 1990-03-07 | 1991-09-08 | Sala International Ab | DEVICE FOR MILLING OF MINERAL PRODUCTS |
SE469417B (en) * | 1991-12-20 | 1993-07-05 | Sala International Ab | SETTING AND DEVICE FOR FINAL PAINTING OF FOOD FILLER DAMAGES APPLICABLE MINERALS IN DRY CONDITION |
SE502566C2 (en) * | 1992-12-04 | 1995-11-13 | Cementa Ab | Methods for relaying cement |
ATE158202T1 (en) * | 1992-07-07 | 1997-10-15 | Ecc Int Ltd | DIFFERENTIAL GRINDING |
CN106179718A (en) * | 2016-08-02 | 2016-12-07 | 山东华联矿业股份有限公司 | Dressing of middles technique |
CN107812590B (en) * | 2016-09-14 | 2020-01-03 | 中国地质科学院矿产综合利用研究所 | Selective dissociation strengthening separation method for fine particles difficult to separate |
CN108704761A (en) * | 2018-04-24 | 2018-10-26 | 赣州金环磁选设备有限公司 | A method of preparing plank quartz using beach quartz sand |
CN110976069A (en) * | 2020-01-10 | 2020-04-10 | 中建材蚌埠玻璃工业设计研究院有限公司 | Harmless purification method of deep sea phase sedimentary type quartz sand |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2441584A (en) * | 1942-06-20 | 1948-05-18 | Harry L Mcneill | Closed circuit grinding with twostage classification |
US3167502A (en) * | 1962-03-20 | 1965-01-26 | Minerals & Chem Philipp Corp | Process for recovering cassiterite from ores |
DE1261094B (en) * | 1967-07-28 | 1968-02-15 | Siteg Siebtech Gmbh | Method and device for processing by means of flotation |
SE410561B (en) * | 1973-04-13 | 1979-10-22 | Boliden Ab | INSTALLATION FOR AUTOGEN OR SEMIAUTOGEN GRINDING OF PIECE MATERIAL, SPECIAL ORE |
SE382920B (en) * | 1973-08-09 | 1976-02-23 | Platmanufaktur Ab | DEVICE FOR SEPARATION OF PRE-SORTED HOUSEHOLD WASTE |
DE2827924B2 (en) * | 1977-10-13 | 1981-05-21 | Simmering-Graz-Pauker AG für Maschinen-, Kessel- und Waggonbau, Wien | Process for processing floatable minerals and ores |
-
1986
- 1986-10-06 SE SE8604241A patent/SE8604241D0/en unknown
-
1987
- 1987-10-02 DE DE8787850297T patent/DE3767832D1/en not_active Expired - Lifetime
- 1987-10-02 EP EP87850297A patent/EP0267170B1/en not_active Expired
- 1987-10-02 AT AT87850297T patent/ATE60527T1/en not_active IP Right Cessation
- 1987-10-02 ES ES87850297T patent/ES2021395B3/es not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
ATE60527T1 (en) | 1991-02-15 |
SE8604241D0 (en) | 1986-10-06 |
DE3767832D1 (en) | 1991-03-07 |
ES2021395B3 (en) | 1991-11-01 |
EP0267170A1 (en) | 1988-05-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5338337A (en) | Beneficiation process | |
EP0267170B1 (en) | Treatment of middlings | |
US3912174A (en) | Process for preparation ores for concentration | |
US4860957A (en) | Treatment of middlings | |
US2962231A (en) | Beneficiation of ores | |
CN110624686A (en) | Magnetite beneficiation process capable of fully releasing mill capacity | |
CN114178046B (en) | Beneficiation method for pyrochlore | |
US3791595A (en) | Method for processing iron ore concentrates | |
US4206878A (en) | Beneficiation of iron ore | |
AU2020101235A4 (en) | Method for the Beneficiation of Iron Ore Streams | |
US3291398A (en) | Beneficiation of magnetic iron ores | |
Clarke et al. | Technical note Enhancement of cassiterite liberation by high pressure roller comminution | |
RU2241544C2 (en) | Method of enrichment of magnetite ores | |
US3414201A (en) | Talc beneficiation method | |
RU2370327C2 (en) | Ore-concentration movable modular complex | |
US2307064A (en) | Ore dressing | |
RU2132742C1 (en) | Method of concentrating magnetite ores | |
US3806046A (en) | Dry extraction and purification of phosphate pebbles from run-of-mine rock | |
CA1225977A (en) | Asbestos process | |
US2890795A (en) | Metallurgical processing of uranium ores | |
JPH034610B2 (en) | ||
RU2131780C1 (en) | Process of beneficiation of manganese ore | |
RU2104797C1 (en) | Method of separating brass slags | |
RU2097138C1 (en) | Method of dressing mixed iron ores | |
JPS59207825A (en) | Method for recovering scaly graphite |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT DE ES FR GR IT SE |
|
17P | Request for examination filed |
Effective date: 19881022 |
|
17Q | First examination report despatched |
Effective date: 19900530 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT DE ES FR GR IT SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 19910130 Ref country code: AT Effective date: 19910130 |
|
REF | Corresponds to: |
Ref document number: 60527 Country of ref document: AT Date of ref document: 19910215 Kind code of ref document: T |
|
ET | Fr: translation filed | ||
REF | Corresponds to: |
Ref document number: 3767832 Country of ref document: DE Date of ref document: 19910307 |
|
ITF | It: translation for a ep patent filed |
Owner name: STUDIO TORTA SOCIETA' SEMPLICE |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
EAL | Se: european patent in force in sweden |
Ref document number: 87850297.0 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20030930 Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20031017 Year of fee payment: 17 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20031028 Year of fee payment: 17 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20041004 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050503 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050630 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20051002 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20041004 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20061009 Year of fee payment: 20 |