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
  • 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
  • C21C7/06—Deoxidising, e.g. killing
• • 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
  • C21C1/10—Making spheroidal graphite cast-iron
• • 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
  • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
  • C22B9/10—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with refining or fluxing agents; Use of materials therefor, e.g. slagging or scorifying agents

Definitions

• This invention relates to deoxidising and/or desulphurising molten non-ferrous metals or alloys, particularly molten copper or copper matte.
• blowing is discontinued when the blister copper stage has been reached, at which stage the sulphur content is usually less than 0.01 percent and the oxygen content less than 1 percent. Although not generally practised blowing may be discontinued at any other stage of the converter process.
• Blister copper must be further refined before use ir-' OBJECTS OF THIS INVENTION It is accordingly a principal object of the present invention to provide a method of refining non-ferrous metals to remove sulphur and/or oxygen therefrom with greater efficiency than the aforementioned processes.
• Oxygen is customarily removed by poling immersing the ends of green hardwood trees into the molten metal bath and optionally aided by covering the bath with coke or other carbonaceous material. This method is difficult and inconvenient to carry out and is fundamentally inefficient. It is also prodigal of trees.
• the step of adding to the melt a treatment agent in the form of a body of porous earbonaceous refractory material impregnated with sodium. potassium. calcium or magnesium or an alloy containing at least 20 percent by weight of one or more of these.
• a process for the refining of copper which comprises blowing air or air enriched with oxygen into molten copper or matte until the residual oxygen content of the molten copper reaches a value of not more than 0.3 percent by weight, and adding to the molten copper a treatment agent in the form of a body of porous carbonaceous refractory material impregnated with sodium, potassium, calcium or magnesium or an alloy containing at least 20 percent by weight of one or more of these.
• a process for the production of copper which comprises blowing air or air enriched with oxygen into molten copper or matte until the residual sulphur content of the molten copper has been reduced to not more than 1 percent and adding to the molten cop per a treatment agent in the form of a body of porous carbonaceous refractory material impregnated with sodium potassium calcium or magnesium. or an alloy containing at least 20 percent of one or more of these.
• the preferred porous carbonaceous refractory material is coke and the preferred impregnants are sodium and magnesium.
• Treatment agents as just defined are preferably used bu immersing them in the molten metal under treatment, for example, by plunging. Because of the heat in the molten metal, the impregnant metal vaporises and the vapour effects a deoxidising and desulphurising action on the molten metal.
• the efficiency of sulphur and/or oxygen removal using treatment agents according to the invention will depend on such factors as molten metal temperature. configuration of the treatment vessel and treatment time may vary from 40 percent to percent.
• metal-impregnated treatment agents as defined above, it may even be possible to dispense with one or more separate refining operations at present considered necessary in copper or other non-ferrous metal production, For instance in the copper refining sequence noted above, the purity of copper from the converter may be so raised that anodes for electrolytic refining may be cast directly from the converter without further need for fire refining.
• the oxygen content of the molten copper can easily be reduced to below 0.05 percent by weight.
• the process of the invention has been described with reference to the smelting or refining of a copper containing melt, it may also be used in the processing of mattes and matte-like materials containing one or more of the following metals nickel, cobalt, zinc, lead, gold, silver and platinum, or in the treatment of metals such as nickel and nickel alloys.
• EXAMPLE I containing 44 percent magnesium were then plunged into the molten copper using a plumbago plunger until reaction was complete. After reaction had taken place the melt was allowed to stand for 5 minutes in order that solid desulphurisation products could rise tothe surface of the molten copper. Further suction samples of molten copper were then taken from the lower part of the crucible.
• Oxygen content before treatment Oxygen content after treatment EXAMPLE lll Molten copper from a converter was transferred into a 25 tonne treatment ladle, and was treated at a temperature of l,23()C with 350kg magnesium impregnated coke containing 44 percent magnesium. The treatment time was 20 minutes.
• the improvement which comprises continuing to blow air optionally enriched with oxygen into the molten copper or matte until the residual oxygen content of the molten copper reaches a value of not more than 0.3 percent by weight, and thereafter adding to the molten copper a treatment agent in the form of a body of porous coke impregnated with sodium, potassium, calcium, magnesium or an alloy containing at least 20 percent of one or more of these.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Treatment Of Steel In Its Molten State (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10441510

Family Applications (1)

Country Status (6)

Cited By (5)

Citations (9)

• 1971
  • 1971-10-06 GB GB4650071A patent/GB1369494A/en not_active Expired
• 1972
  • 1972-10-02 US US294071A patent/US3868248A/en not_active Expired - Lifetime
  • 1972-10-05 FR FR7235342A patent/FR2155601A5/fr not_active Expired
  • 1972-10-05 JP JP47100259A patent/JPS4845422A/ja active Pending
  • 1972-10-05 CA CA153,331A patent/CA997936A/en not_active Expired
  • 1972-10-06 ZM ZM162/72*UA patent/ZM16272A1/xx unknown

Patent Citations (9)

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