Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C1/00—Refining of pig-iron; Cast iron
  • C21C1/02—Dephosphorising or desulfurising
  • C21C1/025—Agents used for dephosphorising or desulfurising
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/04—Removing impurities by adding a treating agent
  • C21C7/064—Dephosphorising; Desulfurising
  • C21C7/0645—Agents used for dephosphorising or desulfurising

Definitions

• the present invention relates to a method for producing desulfurizing agents based on calcium oxide-containing calcium carbide for pig iron and steel melts.
• lime calcium carbide
• lime calcium oxide
• the finely divided lime was preferably introduced into the jet of carbide tapped from the furnace. Although the amount of lime that can be introduced into the molten carbide is limited and working with liquid carbide is dangerous, it was previously thought in specialist circles that this method could not be dispensed with because it was believed that only a mixture of CaC produced in the melt 2 and CaO are best suited for the desulfurization of metal melts.
• This mixture is then milled with intensive mixing and with the exclusion of moisture at temperatures above 100 ° C. to grain sizes less than 10 mm, preferably less than 10 ⁇ m, and the milled product, likewise with the exclusion of moisture, is cooled.
• a carbide / lime starting melt mixture with a CaO content of 20 to 45% by weight which was obtained in a known manner from lime and coke by thermal means.
• a carbide / lime starting melt mixture with a CaO content of more than 45 to 80% by weight is first produced by finely dividing into a carbide melt which has a lime content of up to 45% by weight Enter lime up to a CaO content of up to 80% by weight and only then allow the whole to solidify into a block before breaking it at temperatures above 400 ° C.
• the process according to the invention also has the further advantages, inter alia, that a certain Möller composition is not set in each case to produce the carbide melt, and that the lime is not previously adjusted to a specific grain size must be finely ground, but that it can be assumed that a carbide block whose CaC 2 : CaO weight ratio can fluctuate within a very wide range, ie can be practically arbitrary, and the lime also in coarse-grained form, for example in a grain size between 8 and 60 mm, can be used.
• the block After the block had cooled to an average temperature of about 600 ° C, it was crushed to grain sizes smaller than 150 mm and the carbide, which was still 500 ° C, was covered with so much lime with a grain size of 8 to 60 mm that the resulting mixture contained a total CaO content of 50% by weight.
• the mixture was then ground with the exclusion of moisture at a temperature of 100 ° C. to particle sizes between 0 and 100 ⁇ m, and the ground product was cooled to room temperature with the exclusion of moisture.
• Carbide is thermally produced in a known manner from lime and coke, the lime / coke mixture in the entire Möller being adjusted to a weight ratio of approximately 110:40, which corresponds to a carbide with a CaO content of approximately 45% by weight.
• CaO with a grain size of 3-8 mm is added to the tapping jet of this carbide in such an amount that an average content of approx. 80% by weight CaO results in the tapping crucible (about 1.2-1.3 t Ca0 per 1 t tapping jet).
• the block is pre-crushed to a grain size of less than 150 mm and as much lime with a grain size of 8-60 mm is layered on the hot mixture that the average Ca0 content is 90% by weight.
• the mixture is then ground to a grain size of less than 100 ⁇ m with exclusion of moisture at a temperature above 100 ° C., and the ground product is cooled to room temperature with the exclusion of moisture.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
• Coating With Molten Metal (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6071196

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (7)

Family Cites Families (7)

• 1979
  • 1979-05-19 DE DE19792920353 patent/DE2920353A1/de not_active Withdrawn
• 1980
  • 1980-04-14 AT AT80101984T patent/ATE2092T1/de not_active IP Right Cessation
  • 1980-04-14 DE DE8080101984T patent/DE3061404D1/de not_active Expired
  • 1980-04-14 EP EP80101984A patent/EP0019086B1/de not_active Expired
  • 1980-04-21 CA CA000350242A patent/CA1141965A/en not_active Expired
  • 1980-05-09 ES ES491355A patent/ES8101120A1/es not_active Expired
  • 1980-05-14 US US06/149,745 patent/US4318822A/en not_active Expired - Lifetime
  • 1980-05-16 ZA ZA00802943A patent/ZA802943B/xx unknown
  • 1980-05-16 NO NO801468A patent/NO151971C/no unknown
  • 1980-05-19 JP JP6545180A patent/JPS55154519A/ja active Granted

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