Classifications

• • 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
  • C22B15/0026—Pyrometallurgy
  • C22B15/0028—Smelting or converting
  • C22B15/0052—Reduction smelting or converting
• • 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
  • C22B15/0026—Pyrometallurgy
  • C22B15/006—Pyrometallurgy working up of molten copper, e.g. refining
• • 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
  • C22B9/006—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with use of an inert protective material including the use of an inert gas

Definitions

• the metal and its impurities are melted.
• the molten material is suitably aerated to oxidize the impurities, some of which pass OK as vapors and gases, While others pass into the slag forming on the top, of the molten copper.
• the sulfur is in part volatilized and in part converted to sulfur dioxide which passes off as a gas.
• the aeration of the molten material is effected in various ways.
• the older method is to flap the top surface of the molten material with a rabble, while admitting air into the refining furnace, in order to subject the impurities to the oxidizing effect of the air.
• a latermethod is to pass air, under pressure, into the body of molten material. The removal of sulfur and/or its compounds is accomplished with considerable difficulty, and a large excess of air must therefore be employed in the refining operation. Both methods have the desirable effect of oxidizing impurities, but the very undesirable eflect of also oxidizing appreciable amounts of the copperfrequently as much as 6%.
• the oxidized copper must then be subjected to a deoxidizing or reducing operation to obtain a relatively pure copper product.
• This latter refining or reducing operation is conducted in various ways, generally by the introduction into the body of molten copper of a suitable reducing agent, such as Wooden poles or carbonaceous materials.
• copper contaminated with sulfur and/or its compounds and the like maybe'refined without oxidizing the copper, and the customary deoxidizing or reducing step may therefore be avoided.
• the invention may be practiced in such a way as to desulfurize the copper while oxidizingsome of the copper, but at a material saving in time over what the prior practice requires.
• a body of molten copper contaminated with sulfur and/or itscompounds, hereafter to be referred to as sulfur, and the like is subjected to the action of steam, preferably dry steam under pressure, whereby the copper is desulfurized.
• Steam at thetemperatures employed has the advantage of not oxidizing the molten copper, while at the same time oxidizing the sulfur to form sulfur dioxide gas. Steam, moreover, tends to drive out residual sulfur, as well as other removable impurities present in the copper bath.
• the steam is preferably superheated in order to dry the same.
• This reaction moreover, has the advantage of forming free hydrogen which has the capacity for taking up free oxygen that may be present above the copper to be refined. So
• the invention may be practiced in various ways.
• the molten copper within the refining furnace may first be subjected to the usual air blast or rabbling o 'eration in order to oxidize substantially al of the impurities. That is to say, the aeration or scorification treatment may be conducted until all of the removable impurities, except some sulfur, have been taken out of the copper bath.
• the introduction of air is terminated at that oint, which may be determined by observmg when the formation of slag begins'to cease.
• the copper bath will still contain ap- 1 the copper bath.
• Anot er procedure is to subject themolten material in the refining furnace to the steam treatment of the invention'in order to take out all such impurities as are removable by steam at the temperatures employed. Moreover, the steam treatment may be conducted until the sulfur has been removed. The desulfurized copper bath may then be subjected, if necessary, to the usual air blast in order to remove any remaining impurities. In this manner,the'oxidation of copper may be kept down to a minimum, particularly if a nonoxldizing atmosphere is again maintained a above the copper bath.
• the apparatus usually employed to inject air into copper refining furnaces may advantageously employed for the introduction of steam into the metal bath.
• a 'thorough distribution of the steam may be effected throughout the body of the molten material, it is advisable to introduce steam into the molten bath at a plurality of points,
• the pipes leading from the source of steam to the refining furnace should be insulated to minimize condensation of steam. Special injectors may, of course, be provided for steam alone.
• a molten protecting cover such as described and claimed in my copending application, Serial No. 123,886, filed July 21, 1926, of which this application is a continuation in part, may advantageously be employed to protect the molten, bath from oxidizing influences during the steaming treatment.
• a molten protective cover is contemplated that consists at least in part of soda glass having a melting point not higher, and preferably lower, than that of the copper.
• an oxidizing atmosphere may, of course, be maintained above the metal bath.
• the highly heated molten copper at the top of the metal bath then con- .tacts with the oxygen of the airand copper oxide is formed.
• the use of steam instead of air, particularly at the end of the refining operation is nevertheless advantageously resorted to in order to driveout the sulfur. Even though cop er oxide has been formed, the time of the refining operation will be materially reduced over that heretofore gener required.
• the method of refining copper which comprises maintaining a substantially nonoxidizing atmosphere above the copper in the form of a molten bath while subjecting the molten copper to the action of steam under pressure, said steam being introduced into the body of molten copper, whereby the copper is desulfurized and the formation of copper oxide is inhibited.
• the method of refining copper which comprises maintaining a molten protective cover consisting at least inpart of soda glass having a melting pointnot higher than that of the copper over the copper bath, and introducing steam under pressure into the body of molten copper.
• the method of refining copper which comprises aerating the molten copper partially to remove nnpurities, maintaining a molten protective cover consisting at least in part of soda glass having a melting point not higher than that of the copper over the partially refined copper, and then introducing steam under pressure into the body of molten copper.
• lhe method of refining copper which comprises aerating molten copper partially to remove impurities, then providing a substantially non-oxidizing atmosphere above the copper bath, and introducing steam under pressure into the body of molten copper.
• the method of refining copper containing sulfur as at least one of the contaminants which comprises maintaining an oxidizing atmosphere over the copper bath, introducing steam under pressure into the body of molten copper until only a relativelysmall amount of sulfur remains, then providing a substantially non-oxidizing atmosphere over the copper bath, and introducing further amounts of steam under pressure into the body of partially refined copper to complete the refining operation.
• the method of refining copper containing an appreciable amount-of sulfur as at least one of the contaminating impurities which comprises substantially sealing the furnace in which the refining operation is conducted against the seepage of outside air, and subjecting the copper in the form of a molten bath to the action of steam under pressure whereby the copper is desulphurized and the formation of copper oxide is inhibited.
• the method of refining copper containing sulfur as at least one of the contaminants which comprises maintaining an oxidizing atmosphere over the copper bath by permitting the seepage of outside air into the furnace in which the refining operation is conducted, introducing steam under pressure into the body of molten copper until only a relatively small amount of sulfur remains, then providing a substantially non-oxidizing atmosphere over the copper ath by sealing the furnace against the entrance of outside air, and introducing further amounts of steam under pressure into the body of partially refined copper to complete the refining operation;

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacture And Refinement Of Metals (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23117185

Family Applications (1)

Country Status (2)

• 0
  • BE BE351004D patent/BE351004A/xx unknown
• 1928
  • 1928-07-05 US US290703A patent/US1776826A/en not_active Expired - Lifetime

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