US2448882A - Method for deironing chromium ore - Google Patents

Method for deironing chromium ore Download PDF

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Publication number
US2448882A
US2448882A US603278A US60327845A US2448882A US 2448882 A US2448882 A US 2448882A US 603278 A US603278 A US 603278A US 60327845 A US60327845 A US 60327845A US 2448882 A US2448882 A US 2448882A
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United States
Prior art keywords
chromium
slag
ore
ferro
iron
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Expired - Lifetime
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US603278A
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English (en)
Inventor
Greffe Andre
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Societe dElectro Chimie dElectro Metallurgie et des Acieries Electriques Dugine SA SECEMAU
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    • 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
    • C22B47/00—Obtaining manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B15/00—Other processes for the manufacture of iron from iron compounds
    • C21B15/02—Metallothermic processes, e.g. thermit reduction
    • 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
    • C22B34/00—Obtaining refractory metals
    • C22B34/30—Obtaining chromium, molybdenum or tungsten
    • C22B34/32—Obtaining chromium
    • 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
    • C22B4/00—Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys

Definitions

  • Chromium ores usually contain a considerable proportion of iron.
  • the problem of removing the iron from the said ores is set in a large number of cases and more particularly when one intends to obtain the chromium from the ore in a pure or nearly pure condition.
  • thermo-chemical methods f which are used for carrying out this deironing operation consist essentially in placing in an electric furnace the ore to be treated mixed in a judiciously dosed proportion with a suitable reducing agent and carrying out in said furnace the reduction of the iron contained in the ore, thus removing the iron in metallic form.
  • Reducing agents which are preferably used for this operation are carbon and silicon. Owing to the equilibrium existing between the iron and the chromium contained in the metallic phase on one hand and the corresponding oxides of the molten ore on the other hand, it is necessary, if one wishes to obtain a very low iron oxide content in the ore, to reduce a portion of the chromium oxide of the ore. This involves a decrease in the chromium oxide content of the thus deironed ore, which renders the following operations, for instance the extraction of the chromium in a pure condition, more difficult and more expensive.
  • the present invention relates to a method by which one can avoid the above mentioned inconveniences.
  • This method consists first in partially reducing the chromium ore, preferably in the presence of a ux, as for instance lime, by means of metallic chromium and in separating from the overlying slag the metallic phase rich in iron formed in the course of this operation and then in allowing the slag to freeze, thereafter crushing it and submitting it to a magnetical sorting operation effected by means which are commonly used for this purpose in the treatment of ores.
  • the ferro-chromium obtained in the course of reduction has a composition lwhich is such that the said alloy shows magnetic properties which precisely make it possible, according to the invention, to separate from the slag, after crushing it, the ferro-chromium contained therein'.
  • the chromium used as a reducing agent in the method according to the invention need not be in the condition of a pure metal; it is also possible to work with a ferrochromium alloy having a comparatively high chromium content, for instance
  • the chromium content of the ferro-chromium alloy obtained after the reduction operation is lower than that of the initial alloy, but the said ferro-chromium alloy has a chromium content such that it can be commercially used as low ferro-chromium.
  • the quantity of ferro-chromium used as reducing agent must be calculated as a function of its chromium content in order to obtain a ferro-chromium alloy containing more than 20% of chromium at the end of the reduction operation.
  • the present invention provides for the use of the hereabove dened principal method for the obtention of ferro-chromium having a very high chromium content or even of industrial metallic chromium, for instance thru a largely extended reduction of deironed slag by means of a reducing agent.
  • This reduction can be effected, for instance, in a 3 known manner, by aluminothermy or by means of carbon.
  • a silica-chromium with a low silicon contentl is first caused to act on deironed slag with or without a violent intermixing of the reacting elements and in the presence of a base such as lime, thus giving rise, on one hand, to formation of very rich ferro-chromium or to metallic industrial chromium and, on the other hand to formation of a slag containing silica, lime and chromium oxide, said slag being submitted, in the course of the second stage, to the action of a Silico-chromium with a high silicon content, prepared by the action of silica and carbon on a portion of the deironed slag to be reduced, this second stage, which is preferably effected by a violent intermixing of the phases present, giving rise, on one hand, to a slag which contains only silica and lime and which is removed and, on the other hand, to a Silico-chromium which can be used in the'f
  • Example-A mixture of 300 kg. of chromium ore containing 48.90% of Cr2O3 and 14.34% of FeO with 300 kg. of lime is melted in an electric furnace I.
  • 156 kg. of ferro-chromium containing 67.50% of chromium is charged onto thev surface of 'the bath.
  • the metal 2 and slag 3 are tapped separately from' the furnace, the slag amounting to 587 kg. andv the metal amounting to 94 kg.
  • the slag and. metal. had the following compositions:
  • the slag was allowed to solidify, was crushed and was subjected to a magnetic sorting operation in a magnetic separator 4.
  • the thus deironed slag contained:
  • the ferro-chromium 6 ' was returned to the furnace l for reducing another batch of chromium ore.
  • the slag 1 from the mixer 5 was transferred to a mixer 8 and Silico-chromium 9 having a high ratio of silicon to chromium was added to the mixer 8.
  • the Silico-chromium 9 was made by mixing in a furnace l0 a part of the deironed slag coming from the magnetic separator 4, together with carbon and silica. After violent intermixing in the mixer 8, the slag II was discarded and the silice-chromium I2 having a low ratio of silicon to chromium was returned to the mixer 5 and used for treating another' batch of deironed slag from the magnetic separator 4.
  • a process for the production of a chromium alloy containing less than 2% iron from natural iron and chromium ore which comprises melting said ore and reducing it by metallic chromium in the presence of lime, thereby producing on the one hand an overlying layer of molten slag having a chromium oxide content higher than that in said ore and an iron content lower than that in' said ore and on the other hand an underlying ⁇ layer of molten ferro-chromium, separating the layer of molten ferro-chromium from the layer of molten slag, allowing the slag to freeze, thereafter crushing it and submitting it toa magnetic sorting operation to remove ferrochromium dispersed in the slag, and submitting this deironed slag to. a reduction operation.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
US603278A 1943-12-13 1945-07-04 Method for deironing chromium ore Expired - Lifetime US2448882A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR986931T 1943-12-13
FR986932T 1943-12-13

Publications (1)

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US2448882A true US2448882A (en) 1948-09-07

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US603278A Expired - Lifetime US2448882A (en) 1943-12-13 1945-07-04 Method for deironing chromium ore
US603279A Expired - Lifetime US2458469A (en) 1943-12-13 1945-07-04 Method for deironing chromium and manganese ores

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US603279A Expired - Lifetime US2458469A (en) 1943-12-13 1945-07-04 Method for deironing chromium and manganese ores

Country Status (5)

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US (2) US2448882A (fr)
CH (1) CH259876A (fr)
DE (2) DE821719C (fr)
FR (2) FR986931A (fr)
GB (2) GB598600A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2934422A (en) * 1958-04-30 1960-04-26 Strategic Udy Metallurgical & Chemical Processes Ltd Process for the production of ferrochromium products
US3171736A (en) * 1961-02-13 1965-03-02 United States Steel Corp Method and apparatus for handling slag
US3190722A (en) * 1962-02-23 1965-06-22 Morton Salt Co Method of removing iron from sodium and potassium sulfates
US3301669A (en) * 1964-02-27 1967-01-31 Vanadium Corp Of America Production of a high chromium containing ferrochrome

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2687952A (en) * 1952-07-01 1954-08-31 Us Solicitor Of The Dept Of In Cyclic process for producing high grade synthetic manganese ores by oxidation of molten iron-manganese alloys
DE1188289B (de) * 1960-01-18 1965-03-04 Avesta Jernverks Ab Verfahren zur Anreicherung von eisenhaltigen Chromerzen
AU731820B2 (en) * 1996-10-23 2001-04-05 "Holderbank" Financiere Glarus Ag Process for dechroming, and/or depleting the MgO content of, steel slags

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1136669A (en) * 1912-10-29 1915-04-20 Goldschmidt Thermit Company Process of producing carbon-free ferrochromium.
US1520240A (en) * 1923-05-17 1924-12-23 Hamilton Walter Birkett Reduction of metals
US1717160A (en) * 1924-12-04 1929-06-11 Bethlehem Steel Corp Reduction of complex ores
US2098176A (en) * 1934-03-19 1937-11-02 Marvin J Udy Manufacture of chrome ore preparations
US2127074A (en) * 1937-09-21 1938-08-16 Marvin J Udy Improving chrome ores
US2169741A (en) * 1937-07-22 1939-08-15 Electrochimie Electrometallurg Process for the manufacture of alloys and in particular of ferroalloys or of inoxidizable steels
US2264204A (en) * 1939-09-09 1941-11-25 Eric H Heckett Method and apparatus for reclaiming metal

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US860799A (en) * 1906-05-02 1907-07-23 Hans Goldschmidt Method of manufacturing metals and compositions used therein.
US1820998A (en) * 1928-04-13 1931-09-01 Electro Metallurg Co Smelting of ores

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1136669A (en) * 1912-10-29 1915-04-20 Goldschmidt Thermit Company Process of producing carbon-free ferrochromium.
US1520240A (en) * 1923-05-17 1924-12-23 Hamilton Walter Birkett Reduction of metals
US1717160A (en) * 1924-12-04 1929-06-11 Bethlehem Steel Corp Reduction of complex ores
US2098176A (en) * 1934-03-19 1937-11-02 Marvin J Udy Manufacture of chrome ore preparations
US2169741A (en) * 1937-07-22 1939-08-15 Electrochimie Electrometallurg Process for the manufacture of alloys and in particular of ferroalloys or of inoxidizable steels
US2127074A (en) * 1937-09-21 1938-08-16 Marvin J Udy Improving chrome ores
US2264204A (en) * 1939-09-09 1941-11-25 Eric H Heckett Method and apparatus for reclaiming metal

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2934422A (en) * 1958-04-30 1960-04-26 Strategic Udy Metallurgical & Chemical Processes Ltd Process for the production of ferrochromium products
US3171736A (en) * 1961-02-13 1965-03-02 United States Steel Corp Method and apparatus for handling slag
US3190722A (en) * 1962-02-23 1965-06-22 Morton Salt Co Method of removing iron from sodium and potassium sulfates
US3301669A (en) * 1964-02-27 1967-01-31 Vanadium Corp Of America Production of a high chromium containing ferrochrome

Also Published As

Publication number Publication date
US2458469A (en) 1949-01-04
FR986931A (fr) 1951-08-07
DE916675C (de) 1954-08-16
GB598600A (en) 1948-02-23
CH259876A (fr) 1949-02-15
FR986932A (fr) 1951-08-07
GB619886A (en) 1949-03-16
DE821719C (de) 1951-11-19

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