| abstract |
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 end up in the supernatant. 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 recovered as a metal precursor feed for use in the co-precipitation reaction. In one embodiment, the resin functions as an anion exchange resin with an acidic supernatant to recover Group VIB metal residuals, and a cation exchange resin with a basic supernatant to recover Promoter metal residuals. An effluent stream from the process to waste treatment contains less than 50 ppm metals. |