If the dealer burns a card, it must be kept separate from the muck until all cards have been dealt. If the dealer burns a card and is unable to deal immediately, the dealer may place the burned card back on top of the deck.
Del. Code tit. 28, § 1547
Burned cards
75 Del
Official source: Delaware Code Online. Reproduced from public-domain Delaware statutes; confirm against the official source for the current text. Not legal advice.