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 Ca0 are best suited for the desulfurization of metal melts.
• This mixture is then ground with vigorous mixing and with the exclusion of moisture at temperatures above 100 ° C. to particle sizes of less than 10 mm, preferably less than 10 ⁇ m, and the ground product is cooled, likewise with the exclusion of moisture.
• a calcium carbide-calcium oxide starting melt mixture with a CaO content of 20 to 45% by weight which was obtained in a known manner from lime and coke in a thermal manner.
• a calcium carbide-calcium oxide starting melt mixture with a CaO content of over 45 to 80% by weight is first prepared by adding finely divided calcium oxide to an existing calcium carbide melt which has a calcium oxide content of up to 45% by weight 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 does not have a specific grain size beforehand must be finely ground, but that it can be assumed that a carbide block whose CaC 2: CaO weight ratio fluctuates 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 Ca0 content of 50% by weight.
• the mixture was then ground in the absence 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.
• Ca0 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 Ca0 results in the tapping crucible (about 1.2 - 1.3 t Ca0 per tonne of 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 through Sectional CaO content is 90% by weight.
• the mixture is then ground to a grain size of less than 100 ⁇ m with the exclusion of moisture at a temperature above 100 ° C. and the ground product is cooled to room temperature in the absence 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 (4)

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Citations (5)

Family Cites Families (2)

• 1979
  • 1979-05-19 DE DE19792920353 patent/DE2920353A1/de not_active Withdrawn
• 1980
  • 1980-04-14 DE DE8080101984T patent/DE3061404D1/de not_active Expired
  • 1980-04-14 AT AT80101984T patent/ATE2092T1/de not_active IP Right Cessation
  • 1980-04-14 EP EP80101984A patent/EP0019086B1/fr not_active Expired
  • 1980-04-21 CA CA000350242A patent/CA1141965A/fr not_active Expired
  • 1980-05-09 ES ES491355A patent/ES491355A0/es active Granted
  • 1980-05-14 US US06/149,745 patent/US4318822A/en not_active Expired - Lifetime
  • 1980-05-16 NO NO801468A patent/NO151971C/no unknown
  • 1980-05-16 ZA ZA00802943A patent/ZA802943B/xx unknown
  • 1980-05-19 JP JP6545180A patent/JPS55154519A/ja active Granted

Patent Citations (5)

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