In a process for forming a bulk hydroprocessing catalyst by sulfiding a catalyst precursor made in a co-precipitation reaction, up to 60% of the metal precursor feeds do not react to form catalyst precursor and end up in the supernatant. In the present disclosure, the metals can be recovered via any of chemical precipitation, ion exchange, electro-coagulation, and combinations thereof to generate an effluent stream containing less than 50 mole % of metal ions in at least one of the metal residuals, and for at least one of the metal residuals is recovered as a metal precursor feed, which can be recycled for use in the co-precipitation reaction. An effluent stream from the process to waste treatment contains less than 50 ppm metal ions.