For purposes of the Trade Expansion Act of 1962 [19 U.S.C. 1801 et seq.], section 201(b)(1) [19 U.S.C. 1821(b)(1)] (relating to limit on decrease in duty), sections 221, 223, and 224 [19 U.S.C. 1841, 1843, 1844] (relating to certain requirements concerning negotiations), and section 253 [19 U.S.C. 1883] (relating to staging requirements) of such Act shall not apply with respect to dicyandiamide provided for in item 425.40 of the Tariff Schedules of the United States, and shall not apply with respect to limestone, when imported to be used in the manufacture of cement, provided for in item 513.34 of such Schedules.