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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F14/00—Inhibiting incrustation in apparatus for heating liquids for physical or chemical purposes
  • C23F14/02—Inhibiting incrustation in apparatus for heating liquids for physical or chemical purposes by chemical means
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
  • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
  • C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
  • C02F5/14—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus
  • C02F5/145—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing phosphorus combined with inorganic substances
• • 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
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
  • C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
  • C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
  • C23G1/066—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors phosphorus-containing compounds

Definitions

• the present invention relates to a system for inhibiting the formation of water insoluble divalent metal salt deposits removing or reducing such deposits or of leaching metal therefrom.
• the said system includes a composition adapted to inhibit or reduce such deposits, a method of making said composition and the use of said composition for the aforesaid purpose.
• a number of water insoluble divalent metal salts are associated with problems of scaling or blockage, e.g. in the water treatment and oil industries. Examples include the carbonates and sulphates of calcium and barium.
• a particular problem in the oil industry is ferrous sulphide which forms extensive deposits in oil wells, obstructing the flow through wells and adjacent strata.
• Other insoluble divalent metal salts would be potentially valuable sources of the metals if they could be solubilised or leached economically.
• the invention provides a composition
• a composition comprising: (A) at least 0.01% by weight of a tetrakis (hydroxymethyl) phosphonium salt; (B) an ammonium salt in a ratio of A: B of from 0.01 to 100: 1 (C) sufficient of an acid which is substantially unreactive with tetrakis (hydroxymethyl) phosphonium ion or ammonium ion, to maintain the pH below 4:5; and (D) either sufficient of an aqueous solvent to dissolve the other components or a particulate or porous solid diluent which may consist at least in part of component (C), in an amount sufficient to absorb said components (A) and (B) .
• the water soluble tetrakis (hydroxymethyl) phosphonium salt (A) may be the sulphate (THPS) , the chloride (THPC) or the phosphate.
• the salt may be a salt of any other acid which does not react with the phosphonium ion, such as bromide, phosphite, formate, acetate, trichloracetate, borate or sulphite.
• it is a salt of a strong acid which is not displaced at the pH of the composition.
• the concentration of A in the composition is greater than 1% by weight, usually greater than 5% by weight, more usually greater than 10% by weight, typically greater than 20% by weight, more preferably greater than 30% by weight, most preferably greater than 40% by weight, especially greater than 50% by weight, more especially greater than 60% by weight, e.g. 65 to 85% by weight, for instance 70 to 80% by weight.
• the ammonium salt (B) may be any water soluble ammonium salt such as ammonium sulphate, ammonium chloride, or an ammonium salt of any of the other acids mentioned above in the context of the tetrakis (hydroxymethyl) phosphonium salt.
• the salt (B) may be ammonium bromide, phosphite, formate, acetate, trichloracetate, borate or sulphite.
• the weight ratio of component A to component B is preferably from 0.05 to 50: 1 , more preferably 0J to 30:1 , most preferably 0.5 to 20:1, typically 0.6 to 10: 1 especially 0.7 to 8:1 , more especially 0.8 to 5:1 , e.g. 0.9 to 3: 1.
• the pH is preferably below 4.3, especially below 4, most preferably below 3.5, typically below 3, e.g. 0.1 to 2.5, for instance 0.5 to 2.
• the acid (C) may be sulphuric, hydrochloric, phosphoric or any of those discussed above in connection with the salts, which is sufficiently strong to maintain the required pH.
• the acid (C) may be hydrobromic acid, phosphorous acid, formic acid, acetic acid, trichloracetic acid, boric acid or sulphurous acid.
• A, B and D all comprise a common anion.
• the composition may additionally comprise other water treatment agents which are chemically compatible with A, B and C.
• scale or corrosion inhibitors such as 1-hydroxyethane-l J-diphosphonic acid, amino methylenephosphonic acids, including amino tris (methylenephosphonate) , ethylenediamine tetrakis (methylenephosphonate), diethylenetriamine pentakis (methylenephosphonate) , triethylene tetramine hexakis (methylenephosphonate) and higher homologues in the same series
• ethanolamine bis (methylenephosphonate) phosphonocarboxylic acids, including phosphonosuccinic acid, and phosphonated telomers of maleic, fumaric and/or acrylic acid, and copolymers of acrylic, maleic, vinyl phosphonic, vinyl sulphonic and/or vinyl diphosphonic acids
• oxygen scavengers such as hydroxylamine
• sequestrants such as sodium tripolyphosphate or potassium pyrophosphate
• surfactants including ani
• the composition may be an aqueous solution.
• the composition may be obtained in solid form by coating the solution upon, or absorbing it into, a particulate or porous solid substrate.
• a solution of (A) and (B) is coated onto or absorbed into a particulate or porous solid acid which constitutes components (C) and (D) .
• the substrate should be chemically inert to component A and preferably acidic in character.
• Particularly preferred are organic fatty acids, dicarboxylic acids or hydroxy carboxylic acids such as maleic acid, pimelic acid, suberic acid, azelaic acid, stearic acid, oleic acid, linoleic acid, palmitic acid, succinic acid, glutaric acid, or preferably, adipic acid.
• the present invention also provides a method of making the composition hereinabove described.
• the solid composition may be obtained by spraying the solution, or separate solutions of A and B, onto the substrate, or by mixing the solution or solutions with the substrate and extruding, drying and pulverising the product. It is possible, though usually less convenient, to prepare separate solids comprising A and B respectively and mix them.
• the power may be compacted into granules or tablets, or may be enclosed in water soluble bags or sachets formed from a water-soluble, film-forming polymer, such as polyvinyl alcohol.
• the present invention further provides the use of the composition to reduce the deposit of water-insoluble divalent metal salts in a water system.
• the composition may be added directly to alkaline, neutral or weakly acidic water systems (e.g. at pH down to 5) to dissolve or leach divalent metal, usually in a sufficient dosage to provide 0.1 to l .OOOppm THP in the system, more preferably 0.5 to 500ppm, e.g. 1 to 400ppm, especially 5 to 300ppm, more especially 10 to 200ppm, most especially 20 to lOOppm. It may be convenient, at least partially, to neutralise the acid composition prior to addition to neutral or acidic water systems.
• a solution of 50% by weight THPS and 25% by weight ammonium sulphate was sprayed as a fine mist onto an air fluidised bed of powdered adipic acid at 40°C.
• the product was a free flowing powder containing 11% by weight THPS, 6 % by weight ammonium sulphate and 3% moisture. The product was stable on storage.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Detergent Compositions (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Extraction Or Liquid Replacement (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=26314506

Family Applications (1)

Country Status (6)

Families Citing this family (13)

Family Cites Families (6)

• 1999
  • 1999-10-08 EP EP99949196A patent/EP1133450A1/de not_active Withdrawn
  • 1999-10-08 WO PCT/GB1999/003352 patent/WO2000021892A1/en not_active Application Discontinuation
  • 1999-10-08 AU AU62174/99A patent/AU6217499A/en not_active Abandoned
  • 1999-10-13 AR ARP990105165 patent/AR020790A1/es unknown
  • 1999-10-13 CO CO99065017A patent/CO5320611A1/es not_active Application Discontinuation
• 2001
  • 2001-03-23 NO NO20011504A patent/NO20011504L/no not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events