US PATENT SUBCLASS 71 / 40
.~.~.~.~.~ Sulfuric acid

Current as of: June, 1999
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71 /   HD   CHEMISTRY: FERTILIZERS

1  DF  PROCESSES AND PRODUCTS {5}
31  DF  .~ Inorganic material {5}
32  DF  .~.~ Phosphorus-containing {1}
33  DF  .~.~.~ Phosphates {6}
37  DF  .~.~.~.~ Acid treatment {4}
40.~.~.~.~.~ Sulfuric acid

DEFINITION

Classification: 71/40

(under subclass 37) Processes wherein the acid used in H2SO4.

SEE OR SEARCH THIS CLASS, SUBCLASS:

37, for H2SO4 mixed with another acid.

38, for treatment with sulphuric acid anhydride.