Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B5/00—Treatment of  metallurgical  slag ; Artificial stone from molten  metallurgical  slag 
  • C04B5/06—Ingredients, other than water, added to the molten slag or to the granulating medium or before remelting; Treatment with gases or gas generating compounds, e.g. to obtain porous slag
• • 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
  • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
  • C22B7/04—Working-up slag
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B3/00—General features in the manufacture of pig-iron
  • C21B3/04—Recovery of by-products, e.g. slag
  • C21B3/06—Treatment of liquid slag
• • 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
  • C22B15/00—Obtaining copper
• • 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
  • C22B5/00—General methods of reducing to metals
  • C22B5/02—Dry methods smelting of sulfides or formation of mattes
  • C22B5/06—Dry methods smelting of sulfides or formation of mattes by carbides or the like
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B2400/00—Treatment of slags originating from iron or steel processes
  • C21B2400/02—Physical or chemical treatment of slags
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies

Definitions

• the invention relates to a process for the reduction and / or purification of a slag containing a metal.
• the present invention relates in particular to a process for the intensive reduction of a melt and the conversion of copper slags in particular and the recovery of copper from these. But it can also be used for slag containing other metals.
• the melting of copper concentrates produces stone and slag. Mudstone is converted into blister copper and the slag is sent to the slag cleaning process.
• the purification of copper slag is carried out by various technologies such as reduction and sedimentation, hydrometallurgical slag leaching or slag flotation after slow cooling, comminution and grinding. Pyrometallurgical processes are based on slag processing in an electric furnace, Teniente slag cleaning furnace or a smelting converter.
• Copper is present in the slag in the form of inclusions of copperstone in the size of 5 to 1000 ⁇ m and dissolved copper (I) oxide.
• the recovery of copperstone inclusions requires the reduction of magnetite to reduce the apparent viscosity of slag and to release trapped inclusions by magnetite crystals.
• US 5,865,872 discloses a process for recovering metal and producing a secondary slag from the base metal where at least one reducing agent is added to the slag, various means being contemplated. In particular, carbon is used, with a share of up to 40% being proposed.
• the use of iron silicate to recover metals from slags is provided in US 5,626,646. Also according to the method proposed in US 4,036,636, the addition of a solid reducing agent is provided in the recovery of nickel from a melt.
• the invention has for its object to propose an improved process for the reduction of a metal-containing melt.
• the solution of this problem by the invention is characterized in that the slag is added as a reducing agent calcium carbide (CaC 2 ).
• the calcium carbide (CaC 2 ) is preferably supplied in an amount between 0.1 and 2.0% of the slag mass, with an amount of between 0.5 and 1.5% of the slag mass being particularly preferred.
• the determination of the amount of calcium carbide (CaC 2 ) supplied preferably takes place as a function of the content of magnetite and / or copper (I) oxide in the slag.
• the calcium carbide (CaC 2 ) can be added to the molten slag. It can be charged into an oven before the molten slag is charged into the oven. But it can also be provided that the calcium carbide (CaC 2 ) on the surface of which are located in an oven molten slag is charged. Furthermore, it may be provided that the calcium carbide (CaC ⁇ ) is charged into the interior of the molten slag in an oven. In this case, the calcium carbide (CaC 2 ) can be introduced into the interior of the molten slag by means of a blowing nozzle or by means of a lance.
• another reducing agent can be added.
• a further reducing agent comes once a solid material, in particular coke, charcoal and / or pig iron, into consideration.
• a carbon-containing substance in particular bunker oil, diesel oil, natural gas and / or coal dust.
• the further reducing agent can be blown into the molten slag.
• the slag preferably contains copper (Cu). But it is also possible that the slag contains lead (Pb), zinc (Zn), platinum (Pt) or nickel (Ni).
• the invention is based on a new process of intensive slag reduction and purification. It is a pyro-metallurgical process of slag reduction and purification.
• the intensive slag reduction may include:
• the reaction is exothermic at 1250 ° C.
• the heat generated leads to an increase in the temperature at the transition between liquid slag / carbide, which, together with a change in the slag structure at the transition through CaO leads to a significant acceleration of the reduction rate.
• calcium carbide is fed through the opening into the furnace.
• the amount of calcium carbide is determined by the composition of the slag, in particular by the magnetite content, and varies from 0.5 to 1.5% of the total slag mass.
• the slag is poured slowly through the furnace mouth or the trough into the furnace.
• An intense reduction reaction during charging lowers the magnetite content to the required level of about 5%. Due to the exothermic effect of the reaction, the slag temperature during charging and reduction increases from 1250 to 1263 0 C, if the burned fuel covers the heat losses of the furnace.
• slag reduction is complete and the settling process begins, followed by stripping the slag and cutting off the copper mat, which is identical to the classical process.
• the cycle of slag cleaning can be shortened in the Teniente oven by about 50%, which corresponds to a twofold increase in the kiln slag treatment capacity.
• Melt slag is processed in the electric furnace by reduction with coke and the carbon from electrodes, whereby the overheating follows the sedimentation.
• the calcium carbide is charged into the furnace.
• the addition of calcium carbide is dependent on the slag composition and is in the range of 0.5 to 1.5% of the slag mass.
• liquid slag is poured into the furnace.
• the heavy, rapid slag reduction occurs through the contact of carbide grains and the slag stream.
• Calcium carbide begins to float on the slag surface and the reduction proceeds with immersed electrodes and supply of electrical energy. Due to the exothermic effect of the reduction reactions, the slag temperature does not decrease.
• the electrical power input is controlled to cover the heat losses and cause a slight increase in slag temperature.
• the degree of magnetite reduction and co-reduction of copper (I) oxide is higher, thus ensuring the increase in copper recovery.
• a very intensive slag reduction makes it possible to shorten the reduction time while maintaining a similar sedimentation time. This results in a shorter cycle due to the intensive reduction, which in turn ultimately leads to an increase in the productivity of the furnace.
• Replacing coke as a reducing agent with calcium carbide reduces the unit energy consumption and also significantly reduces the unit consumption of reducing agent.

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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)
• Ceramic Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Structural Engineering (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Processing Of Solid Wastes (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2006
  • 2006-05-16 DE DE200610022780 patent/DE102006022780A1/de not_active Withdrawn
  • 2006-06-08 KR KR20077017052A patent/KR20080012255A/ko not_active Ceased
  • 2006-06-08 CA CA 2605390 patent/CA2605390A1/en not_active Abandoned
  • 2006-06-08 EP EP06754231A patent/EP1888796A1/de not_active Ceased
  • 2006-06-08 RU RU2007129747A patent/RU2358026C2/ru not_active IP Right Cessation
  • 2006-06-08 AU AU2006256915A patent/AU2006256915A1/en not_active Abandoned
  • 2006-06-08 US US11/921,583 patent/US7819941B2/en not_active Expired - Fee Related
  • 2006-06-08 WO PCT/EP2006/005496 patent/WO2006131371A1/de not_active Ceased
  • 2006-06-08 BR BRPI0610887-3A patent/BRPI0610887A2/pt not_active IP Right Cessation
  • 2006-06-08 MX MX2007015384A patent/MX2007015384A/es active IP Right Grant
  • 2006-06-08 JP JP2008515140A patent/JP2008542549A/ja not_active Withdrawn
• 2007
  • 2007-08-17 NO NO20074215A patent/NO20074215L/no not_active Application Discontinuation

Non-Patent Citations (1)

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