US PATENT SUBCLASS 423 / 522
.~.~.~ Sulfuric acid


Current as of: June, 1999
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423 /   HD   CHEMISTRY OF INORGANIC COMPOUNDS

511  DF  SULFUR OR COMPOUND THEREOF {4}
512.1  DF  .~ Oxygen containing {11}
521  DF  .~.~ Ternary compound containing hydrogen {1}
522.~.~.~ Sulfuric acid {5}
523  DF  .~.~.~.~> Nitrogenous impurity or utilizing nitrogenous catalyst or reactant {1}
525  DF  .~.~.~.~> Starting material includes organic or carbonaceous impurity {3}
529  DF  .~.~.~.~> Subjecting reactants to pressure, vacuum, or steam
530  DF  .~.~.~.~> Utilizing metal sulfate
531  DF  .~.~.~.~> Purifying acid or reactant


DEFINITION

Classification: 423/522

(under subclass 521) Products or processes in which the ternary compound is sulfuric acid (H2SO[supscrpt]4[end supscrpt]).

(1) Note. This subclass provides for sulfuric acid (H2SO4) including fuming sulfuric acid which is sometimes termed oleum or Nordhausen acid for which sometimes the formula H2S2[end subscrpt]O7 may be designated. However, this compound is actually H2[end subscrpt]SO4 with SO3[end subscrpt] dissolved therein and is classified in this subclass.