US2860044A - Method in the production of iron powder of desired grain size - Google Patents
Method in the production of iron powder of desired grain size Download PDFInfo
- Publication number
- US2860044A US2860044A US211982A US21198251A US2860044A US 2860044 A US2860044 A US 2860044A US 211982 A US211982 A US 211982A US 21198251 A US21198251 A US 21198251A US 2860044 A US2860044 A US 2860044A
- Authority
- US
- United States
- Prior art keywords
- powder
- grain size
- iron
- production
- mesh
- 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 - Lifetime
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims description 36
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 238000000034 method Methods 0.000 title claims description 8
- 229910052742 iron Inorganic materials 0.000 claims description 13
- 239000002245 particle Substances 0.000 claims description 3
- 238000005272 metallurgy Methods 0.000 claims 1
- 239000000843 powder Substances 0.000 description 20
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 10
- 241000243142 Porifera Species 0.000 description 10
- 235000012461 sponges Nutrition 0.000 description 10
- 239000012141 concentrate Substances 0.000 description 5
- 238000001816 cooling Methods 0.000 description 4
- 238000003801 milling Methods 0.000 description 4
- 238000004663 powder metallurgy Methods 0.000 description 4
- 238000000227 grinding Methods 0.000 description 3
- 239000003610 charcoal Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- 235000002198 Annona diversifolia Nutrition 0.000 description 1
- 241000282838 Lama Species 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
- H03G3/20—Automatic control
- H03G3/22—Automatic control in amplifiers having discharge tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0086—Conditioning, transformation of reduced iron ores
Definitions
- sponge iron When sponge iron is produced from oxide in powder form, especially if coke or charcoal is used as reducing agent, the temperature must, in practice, be so high that the sponge iron is obtained as hard, sintered cakes of considerable strength. These cakes can, after crushing, be ground to a powder.
- Such sponge iron powder can be used for powder metallurgical purposes if certain conditions are fullfilled. These are:
- the powder must pass a 100 mesh screen.
- the volume weight must not exceed 2.5, which means that the milling must be done in such a way that the grains substantially retain their orginal porous structure.
- the purpose of this invention is to make possible a more complete conversion of the hard, sintered cakes to a powder suitable for use in powder metallurgy and thus to decrease the up to now unavoidable loss in said powder which will not pass a 100 mesh screen.
- the invention is based on the discovery that the grain size of the iron oxide used as raw material for the sponge iron production has a considerable influence on the production of a powder of wanted grain size. This is rather astonishing since the reduction has to be carried out at a temperature considerably higher than the temperature at which a crystallization and grain growth of iron takes place, wherefore it was to be expected that the original grain boundaries would disappear and be without influence on the grindability. Further each original grain has a considerable porosity which ought to decrease the mechanical strength and make it possible to split it up in the grinding process.
- the iron oxide which is to be used for powder production is, by suitable means such as grinding or sieving, reduced to a grain size which is atent O "ice the same as or less than the grain size desired in the iron powder, whereafter the oxide powder is reduced to sponge iron, which after cooling and crushing is milled to the wanted grain size.
- Example.-Magnetite concentrate was mixed with powdered charcoal in the proportions :33 and the mixture heated to 1000 C. where it was kept until the reduction was complete. After cooling the obtained sponge iron was crushed in a jaw-crusher and milled in a disintegrator. After milling the powder was screened on a 100 mesh sieve and the powder not passing the sieve was milled again. This treatment was repeated several times and the different fractions weighed.
- a method for the production of iron powder of the desired grain size for powder metallurgical purposes which comprises mechanically reducing an iron oxide ore to a particle size not greater than said desired grain size, chemically reducing said iron oxide ore to iron powder at a temperature suflicient to produce spong iron in the form of hard, sintered cakes, cooling said cakes and comminuting them to a powder of said desired grain size.
- a method for the production of iron powder of about 100 mesh and suitable for powder metallurgy which comprises mechanically reducing iron ore of greater particle size to not greater than about 100 mesh, chemically reducing the resulting ore at a temperature sufiicient to produce sponge iron in the form of a hard, sintered cake and cooling and disintegrating said sponge iron cake to about 100 mesh.
Description
Nov. 11, 1958 N. H. BRUNDIN METHOD IN THE PRODUCTION OF IRON POWDER OF DESIRED GRAIN SIZE Filed. Feb. 2o, 195
llamas/f mi llinys InvehTor METHOD TN THE PRODUCTION OF IRON POWDER OF DESIRED GRAIN SIZE Nils H. Brundin, Hoganas, Sweden, assignor to Hoganas- Billesholms Aktiebolag, Hoganas, Sweden, 21 corporation of weden Application February 20, 1951, Serial No. 211,982
3 Claims. (Cl. 75-.5)
When sponge iron is produced from oxide in powder form, especially if coke or charcoal is used as reducing agent, the temperature must, in practice, be so high that the sponge iron is obtained as hard, sintered cakes of considerable strength. These cakes can, after crushing, be ground to a powder. Such sponge iron powder can be used for powder metallurgical purposes if certain conditions are fullfilled. These are:
(1) The powder must pass a 100 mesh screen.
(2) The volume weight must not exceed 2.5, which means that the milling must be done in such a way that the grains substantially retain their orginal porous structure.
Because of this latter reason the grinding must be done very carefully and in practice it has been shown that some conventional mills are not suitable for the purpose. Two types of mills which have been found suitable are the pan mill and the disintegrator in which the treatment is mild enough to let the grains retain their porous structure after milling.
In practice it Was found, however, that it was not possible to grind sponge iron cakes in these mills so that all powder obtained was suitable for use for powder metallurgical purposes. About of the obtained powder would not pass a 100 mesh screen and even if this 20% was recirculated it was not possible to reduce the size any further. Therefore this 20% had to be used for other purposes. It is possible to grind this powder to a finer grain size in a ball mill but even then the powder is not suitable for use in the powder metallurgy because by this treatment the volume weight becomes much higher than the allowed 2.5.
The purpose of this invention is to make possible a more complete conversion of the hard, sintered cakes to a powder suitable for use in powder metallurgy and thus to decrease the up to now unavoidable loss in said powder which will not pass a 100 mesh screen.
The invention is based on the discovery that the grain size of the iron oxide used as raw material for the sponge iron production has a considerable influence on the production of a powder of wanted grain size. This is rather astonishing since the reduction has to be carried out at a temperature considerably higher than the temperature at which a crystallization and grain growth of iron takes place, wherefore it was to be expected that the original grain boundaries would disappear and be without influence on the grindability. Further each original grain has a considerable porosity which ought to decrease the mechanical strength and make it possible to split it up in the grinding process.
According to the invention the iron oxide which is to be used for powder production is, by suitable means such as grinding or sieving, reduced to a grain size which is atent O "ice the same as or less than the grain size desired in the iron powder, whereafter the oxide powder is reduced to sponge iron, which after cooling and crushing is milled to the wanted grain size.
Example.-Magnetite concentrate was mixed with powdered charcoal in the proportions :33 and the mixture heated to 1000 C. where it was kept until the reduction was complete. After cooling the obtained sponge iron was crushed in a jaw-crusher and milled in a disintegrator. After milling the powder was screened on a 100 mesh sieve and the powder not passing the sieve was milled again. This treatment was repeated several times and the different fractions weighed.
One experiment was carried out with a magnetite concentrate passing 40 mesh and one with concentrate passing 100 mesh.
The result is given in the accompanying drawing where the accumulative percentage of powder passing 100 mesh is shown as a function of the number of milling operations.
As is seen from the drawing the unavoidable loss when using 40 mesh concentrate amounted to about 20 percent whereas the corresponding loss when using 100 mesh concentrate as starting material only amounted to about 2.5 percent.
We claim:
1. A method for the production of iron powder of the desired grain size for powder metallurgical purposes which comprises mechanically reducing an iron oxide ore to a particle size not greater than said desired grain size, chemically reducing said iron oxide ore to iron powder at a temperature suflicient to produce spong iron in the form of hard, sintered cakes, cooling said cakes and comminuting them to a powder of said desired grain size.
2. A method for the production of iron powder as defined in claim 1 in which the iron oxide ore is of a grain size capable of passing a 100 mesh screen, is free of carbonizable liquid, is reduced in the presence of a solid reducing agent and at least about 97.5% of the powder produced by comminuting will pass a 100 mesh screen and has a volume weight not greater than about 2.5.
3. A method for the production of iron powder of about 100 mesh and suitable for powder metallurgy which comprises mechanically reducing iron ore of greater particle size to not greater than about 100 mesh, chemically reducing the resulting ore at a temperature sufiicient to produce sponge iron in the form of a hard, sintered cake and cooling and disintegrating said sponge iron cake to about 100 mesh.
References Cited in the file of this patent UNITED STATES PATENTS 2,200,491 Cross et al. May 14, 1940 2,216,770 Drapeau et al Oct. 8, 1940 2,252,697 Brassert Aug. 19, 1941 2,279,013 Roseby Apr. 7, 1942 2,402,120 Boegehold et al June 18, 1946 2,413,492 Firth Dec. 31, 1946 FOREIGN PATENTS 568,786 Great Britain Apr. 20, 1945 OTHER REFERENCES Powder Metallurgy, page 119. Edited by Wultf. Published in 1942 by the American Society for Metals, Cleveland, Ohio.
Claims (1)
- 3. A METHOD FOR THE PRODUCTION OF IRON POWDER OF ABOUT 100 MESH AND SUITABLE FOR POWER METALLURGY WHICH COMPRISES MECHANICALLY REDUCING IRON ORE OF GREATER PARTICLE SIZE TO NOT GREATER THAN ABOUT 100 MESH, CHEMICALLY REDUCING THE RESULTING ORE AT A TEMPERATURE SUFFICIENT TO PRODUCE SPONGE IRON IN THE FORM OF A HARD, SINTERED CAKE
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US211982A US2860044A (en) | 1951-02-20 | 1951-02-20 | Method in the production of iron powder of desired grain size |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US211982A US2860044A (en) | 1951-02-20 | 1951-02-20 | Method in the production of iron powder of desired grain size |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2860044A true US2860044A (en) | 1958-11-11 |
Family
ID=22789052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US211982A Expired - Lifetime US2860044A (en) | 1951-02-20 | 1951-02-20 | Method in the production of iron powder of desired grain size |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2860044A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2990267A (en) * | 1959-06-26 | 1961-06-27 | Dow Chemical Co | Preparation of metal powders |
| US3103315A (en) * | 1959-05-27 | 1963-09-10 | Beteiligungs & Patentverw Gmbh | Method of recovering iron from reduced ores |
| US3214262A (en) * | 1961-11-24 | 1965-10-26 | Huettenwerk Oberhausen Ag | Process for producing dense iron powders from sponge iron |
| US3294590A (en) * | 1962-11-01 | 1966-12-27 | Yardney International Corp | Electrochemical cell |
| US3347659A (en) * | 1965-05-19 | 1967-10-17 | Hydrocarbon Research Inc | Process of reducing iron oxide |
| US3498782A (en) * | 1966-02-18 | 1970-03-03 | Amax Specialty Metals Inc | Compactible fused and atomized metal powder |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2200491A (en) * | 1939-04-13 | 1940-05-14 | Western Electric Co | Manufacture of magnetic materials |
| US2216770A (en) * | 1937-02-11 | 1940-10-08 | Glidden Co | Method of making metal powders and product |
| US2252697A (en) * | 1940-02-01 | 1941-08-19 | Minerals And Metals Corp | Manufacture of metal products |
| US2279013A (en) * | 1940-06-25 | 1942-04-07 | Automatic Telephone & Elect | Method of producting nickel iron powder |
| GB568786A (en) * | 1942-07-01 | 1945-04-20 | William David Jones | A process for the manufacture of composite metal articles |
| US2402120A (en) * | 1943-09-13 | 1946-06-18 | Alfred L Boegehold | Sintered iron article |
| US2413492A (en) * | 1944-04-17 | 1946-12-31 | Continental Machines | Method of producing iron oxide and for production of powdered iron |
-
1951
- 1951-02-20 US US211982A patent/US2860044A/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2216770A (en) * | 1937-02-11 | 1940-10-08 | Glidden Co | Method of making metal powders and product |
| US2200491A (en) * | 1939-04-13 | 1940-05-14 | Western Electric Co | Manufacture of magnetic materials |
| US2252697A (en) * | 1940-02-01 | 1941-08-19 | Minerals And Metals Corp | Manufacture of metal products |
| US2279013A (en) * | 1940-06-25 | 1942-04-07 | Automatic Telephone & Elect | Method of producting nickel iron powder |
| GB568786A (en) * | 1942-07-01 | 1945-04-20 | William David Jones | A process for the manufacture of composite metal articles |
| US2402120A (en) * | 1943-09-13 | 1946-06-18 | Alfred L Boegehold | Sintered iron article |
| US2413492A (en) * | 1944-04-17 | 1946-12-31 | Continental Machines | Method of producing iron oxide and for production of powdered iron |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3103315A (en) * | 1959-05-27 | 1963-09-10 | Beteiligungs & Patentverw Gmbh | Method of recovering iron from reduced ores |
| US2990267A (en) * | 1959-06-26 | 1961-06-27 | Dow Chemical Co | Preparation of metal powders |
| US3214262A (en) * | 1961-11-24 | 1965-10-26 | Huettenwerk Oberhausen Ag | Process for producing dense iron powders from sponge iron |
| US3294590A (en) * | 1962-11-01 | 1966-12-27 | Yardney International Corp | Electrochemical cell |
| US3347659A (en) * | 1965-05-19 | 1967-10-17 | Hydrocarbon Research Inc | Process of reducing iron oxide |
| US3498782A (en) * | 1966-02-18 | 1970-03-03 | Amax Specialty Metals Inc | Compactible fused and atomized metal powder |
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