Biblatex Works Cited + Bibliography

If you are not planning on citing anything from bib.bib, it should be enough to define a labelled refsection with a nocite{*}.

Since refsections are kept completely separate from each other and labelled refsections only take the .bib files from their label, the nocite{*} will only apply to entries from bib.bib.

documentclass[british]{article}
usepackage[T1]{fontenc}
usepackage[utf8]{inputenc}
usepackage{babel}
usepackage{csquotes}

usepackage[style=authoryear, backend=biber]{biblatex}

begin{filecontents}{ref.bib}
@article{sigfridsson,
  author       = {Sigfridsson, Emma and Ryde, Ulf},
  title        = {Comparison of methods for deriving atomic charges from the
                  electrostatic potential and moments},
  journaltitle = {Journal of Computational Chemistry},
  date         = 1998,
  volume       = 19,
  number       = 4,
  pages        = {377-395},
  doi          = {10.1002/(SICI)1096-987X(199803)19:4<377::AID-JCC1>3.0.CO;2-P},
}
@article{herrmann,
  author       = {Herrmann, Wolfgang A. and {"O}fele, Karl and Schneider,
                  Sabine K.  and Herdtweck, Eberhardt and Hoffmann, Stephan D.},
  title        = {A carbocyclic carbene as an efficient catalyst ligand for {C--C}
                  coupling reactions},
  journaltitle = {Angew.~Chem. Int.~Ed.},
  date         = 2006,
  volume       = 45,
  number       = 23,
  pages        = {3859-3862},
}
end{filecontents}
begin{filecontents}{bib.bib}
@book{worman,
  author       = {Worman, Nancy},
  title        = {The Cast of Character},
  date         = 2002,
  publisher    = {University of Texas Press},
  location     = {Austin},
}
@book{nussbaum,
  author       = {Nussbaum, Martha},
  title        = {Aristotle's mkbibquote{De Motu Animalium}},
  date         = 1978,
  publisher    = {Princeton University Press},
  location     = {Princeton},
  keywords     = {secondary},
}
end{filecontents}
addbibresource{bib.bib}
addbibresource{ref.bib}


begin{document}
Lorem cite{sigfridsson}
printbibliography

begin{refsection}[bib.bib]
nocite{*}
printbibliography[title=Bibliography]
end{refsection}
end{document}