US PATENT SUBCLASS 423 / 320-- .~.~.~.~.~ Sulfuric acid

US PATENT SUBCLASS 423 / 320
.~.~.~.~.~ Sulfuric acid

423 /	HD	CHEMISTRY OF INORGANIC COMPOUNDS

299	DF	PHOSPHORUS OR COMPOUND THEREOF {5}
304	DF	.~ Oxygen containing {2}
316	DF	.~.~ Ternary compound containing hydrogen {1}
317	DF	.~.~.~ Orthophosphoric acid {3}
319	DF	.~.~.~.~ Reacting an acid and phosphate rock {1}
320		.~.~.~.~.~ Sulfuric acid

Classification: 423/320

(under subclass 319) Processes in which the acid includes sulfuric acid (H₂SO_{4[end subscrpt]).}