US3494793A - Reduction of hydride losses from molten baths containing hydrides - Google Patents

Reduction of hydride losses from molten baths containing hydrides Download PDF

Info

Publication number
US3494793A
US3494793A US551176A US3494793DA US3494793A US 3494793 A US3494793 A US 3494793A US 551176 A US551176 A US 551176A US 3494793D A US3494793D A US 3494793DA US 3494793 A US3494793 A US 3494793A
Authority
US
United States
Prior art keywords
hydride
losses
melt
bath
reduction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US551176A
Other languages
English (en)
Inventor
Arnold Lenz
Walter Rogler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dynamit Nobel AG
Original Assignee
Dynamit Nobel AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dynamit Nobel AG filed Critical Dynamit Nobel AG
Application granted granted Critical
Publication of US3494793A publication Critical patent/US3494793A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/28—Cleaning or pickling metallic material with solutions or molten salts with molten salts

Definitions

  • This invention relates to a method for the descaling of metal surfaces by pickling in hydride-containing baths which contain as the solvent for the hydride a eutectic or nearly eutectic mixture of sodium hydroxide and potassium hydroxide. More particularly, this invention relates to an improved method for the descaling of metal surfaces by pickling in hydride-containing baths which contain as the solvent for the hydride a eutectic or nearly eutectic mixture of sodium hydroxide and potassium hydroxide, in which the decomposition of the hydride at the baths surface is substantially prevented.
  • a process for descaling metal surfaces has been disclosed in copending application Ser. No. 451,671, now abandoned, in which the pickling is carried out with hydride-containing molten baths which contain as the solvent for the hydride a eutectic or nearly eutectic mixture of sodium hydroxide and potassium hydroxide. These baths can be used for the descaling of steel and non-porous metal articles of many different kindsi.e., wires and strips.
  • the hydride in connection with the replacement of the consumed hydride--i.e., the hydride can be added to the melt in the form of lumps of sodium hydride coated with a eutectic or nearly eutectic mixture of sodium hydroxide and potassium hydroxide, or else in the form of lumps consisting of a homogeneous mass of the eutectic material in which the sodium hydride is embedded.
  • Another object of the invention is the prevention of access of humid air to the surface of a pickling bath con- 3,494,793 Patented Feb. 10, 1970 taining an alkali metal hydride in a simple and inexpensive manner.
  • the process of the present invention makes it possible in a simple and most inexpensive manner to prevent access of moist air to the baths surface.
  • inert shielding gas for use in the invention, there may be employed those dry gases which do not enter into any chemical reaction with the hydride-containing baths prepared with the eutectic mixtures of sodium hydroxide and potassium hydroxide under the conditions of operation.
  • gases include, for example, hydrogen, nitrogen, noble gases, oxygen, air, and saturated aliphatic hydrocarbons having up to 4 carbon atoms. It has proved advantageous in accordance with the invention to adjust the said gas to such a degree of dryness that their water vapor partial pressure amounts to less than about 5 torr.
  • the uncovered areas of the melt are shielded with an inert dry gas to prevent a reaction of the sodium hydride contained in the bath with the moisture content of the air which would result in unnecessary hydride losses.
  • the inert gas can be introduced adjacent the point of introduction of the wires, strips, or the like so that the gas sweeps the atmosphere from the exposed surfaces of the melt. Gas conduits can be provided for this purpose. Other exposed areas of the melt, such as at the sides, can be swept in a like manner. Dry nitrogen has proved particularly well suited as the gas in the shielding.
  • the shielding of the bath surfaces with an inert dry gas can be conducted, for example, with an apparatus to be described below.
  • the figure shows a section through the pickling apparatus parallel to the direction of travel of wires 3 or other elongated metal form.
  • the pickling apparatus consists first of a trough like, elongated vessel 1, which is filled 3 with the fused NaOH-KOH bath 2 containing sodium hydride.
  • the hydride content of the melt is not less than about 1 nor more than about 3% by weight, averaging 2% by weight.
  • Position 2a marks the level of the melt.
  • Heating devices which are necessary for the production of the required working temperatures of about 200 to 240 C., have been omitted for the sake of simplicity.
  • the wires 3 which are to be pickled are introduced continuously from left to right, for example, over ramps leading down into the apparatus, and are guided over a rotatable cylinder 4.
  • Cylinder 4 is mounted in a roller column'4a.
  • the melt 2 is covered on both sides of the roller column 4a by floating pans 5 which can be moved by means of hoists 6.
  • the floating pans 5 are intended to prevent the access of moist air to the surface of the melt.
  • the uncovered areas of the melt, especially where the Wires enter or leave, are expediently shielded with an inert, dry gas according to the present invention to prevent a reaction of the sodium hydride with the moisture content of the air, which would result in unnecessary hydride losses.
  • An inert gas can be introduced adjacent the point of introduction of the wires so that the gas sweeps the atmosphere from exposed surface of the melt. Gas conduits 16 are provided for this purpose.
  • the lower portion is open towards the cage 7 and toward the adjacent wall of the vessel 1.
  • the shaft has an opening for loading charging the basket with hydride. Under the influence of the ballast the charging basket can be brought into the unloading position. Since the hydride has a lower specific gravity than the NaOH-KOH melt, the hydride tends to float and rises slowly upward. Due to the slant of the walls 13 and 14, the lumps containing hydride enter into the portion of the cage 7 which is defined by the horizontal perforated plate. The pieces of hydride then slowly pass into solution.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
US551176A 1965-05-12 1966-05-11 Reduction of hydride losses from molten baths containing hydrides Expired - Lifetime US3494793A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED0047234 1965-05-12

Publications (1)

Publication Number Publication Date
US3494793A true US3494793A (en) 1970-02-10

Family

ID=7050286

Family Applications (1)

Application Number Title Priority Date Filing Date
US551176A Expired - Lifetime US3494793A (en) 1965-05-12 1966-05-11 Reduction of hydride losses from molten baths containing hydrides

Country Status (5)

Country Link
US (1) US3494793A (enrdf_load_html_response)
BE (1) BE680891A (enrdf_load_html_response)
DE (1) DE1546112C3 (enrdf_load_html_response)
NL (1) NL150169B (enrdf_load_html_response)
SE (1) SE300920B (enrdf_load_html_response)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3706600A (en) * 1970-06-26 1972-12-19 Ici Ltd Stripping of coated titanium electrodes for re-coating
US3904102A (en) * 1974-06-05 1975-09-09 Western Electric Co Apparatus and method for soldering, fusing or brazing
US4713120A (en) * 1986-02-13 1987-12-15 United Technologies Corporation Method for cleaning a gas turbine engine
US4834912A (en) * 1986-02-13 1989-05-30 United Technologies Corporation Composition for cleaning a gas turbine engine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2134457A (en) * 1937-03-02 1938-10-25 Tainton Urlyn Clifton Metal treatment
US2188930A (en) * 1938-09-08 1940-02-06 Du Pont Metal cleaning process
US2353026A (en) * 1941-10-18 1944-07-04 Du Pont Metal-cleaning process and composition
US2377876A (en) * 1941-04-23 1945-06-12 Du Pont Metal cleaning process and composition
US2796366A (en) * 1955-10-31 1957-06-18 Du Pont Process and bath for descaling metals
US3126301A (en) * 1961-09-11 1964-03-24 Molten salt spray process for descaling stainless steel

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2134457A (en) * 1937-03-02 1938-10-25 Tainton Urlyn Clifton Metal treatment
US2188930A (en) * 1938-09-08 1940-02-06 Du Pont Metal cleaning process
US2377876A (en) * 1941-04-23 1945-06-12 Du Pont Metal cleaning process and composition
US2353026A (en) * 1941-10-18 1944-07-04 Du Pont Metal-cleaning process and composition
US2796366A (en) * 1955-10-31 1957-06-18 Du Pont Process and bath for descaling metals
US3126301A (en) * 1961-09-11 1964-03-24 Molten salt spray process for descaling stainless steel

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3706600A (en) * 1970-06-26 1972-12-19 Ici Ltd Stripping of coated titanium electrodes for re-coating
US3904102A (en) * 1974-06-05 1975-09-09 Western Electric Co Apparatus and method for soldering, fusing or brazing
US4713120A (en) * 1986-02-13 1987-12-15 United Technologies Corporation Method for cleaning a gas turbine engine
US4834912A (en) * 1986-02-13 1989-05-30 United Technologies Corporation Composition for cleaning a gas turbine engine

Also Published As

Publication number Publication date
SE300920B (enrdf_load_html_response) 1968-05-13
NL6606449A (enrdf_load_html_response) 1966-11-14
BE680891A (enrdf_load_html_response) 1966-11-14
DE1546112C3 (de) 1973-11-22
DE1546112B2 (de) 1973-04-26
DE1546112A1 (de) 1970-08-20
NL150169B (nl) 1976-07-15

Similar Documents

Publication Publication Date Title
US3494793A (en) Reduction of hydride losses from molten baths containing hydrides
Schumb Stability of concentrated hydrogen peroxide solutions
US3048503A (en) Pickling apparatus and method
JPS55128569A (en) Method and apparatus for hot galvanization
US3226315A (en) Continuous electroplating apparatus
KR100268331B1 (ko) 철을 함유하는 재료의 제조방법
US3552404A (en) Installation for the descaling of metals
US3914481A (en) Process of hot dip metallizing of metallic articles
FR2370228A1 (fr) Procede de stockage de l'hydrogene sur un compose de nickel-calcium
Howard Jr et al. The persulfate oxidation of sulfoxides in buffered solution. 1 I
US3928550A (en) Process for making hydrogen
US3414428A (en) Chromizing compositions and methods and continuous production of chromium halides for chromizing
US1592860A (en) Production of carbon monoxide
US4692353A (en) Method of inhibiting degeneration of direct reduced iron
US2279267A (en) Deenameling process
US3481770A (en) Process for preparing alloy diffusion coatings
US3770501A (en) Method and apparatus for removing coatings from metals
US2794001A (en) Descaling metals
JP2532636B2 (ja) 高温コ―クスを冷却及び脱塵する方法及び装置
US3343946A (en) Method and apparatus for converter residue discharge
US2998461A (en) Stabilization of trichloroethylene
SU403766A1 (ru) Способ вакуумйрования жидкого металла
SU990840A1 (ru) Способ переработки отходов щелочных металлов
JPS54162270A (en) Slurry agitating device
DE1546108C (de) Vorrichtung zur Beschickung von Beizschmelzen fur die Entzunderung von Metallflachen