Composition of a filter cake for precious metals recovery

Patent metadata

Field	Value
Publication number	US-2016289792-A1
Application number	US-201615185113-A
Country	US
Kind code	A1
Filing date	Jun 17, 2016
Priority date	Oct 22, 2014
Publication date	Oct 6, 2016
Grant date	—

Abstract

A process is provided for preparing a spent noble metal fixed-bed catalyst for precious metals recovery, comprising: a) adding the catalyst to a caustic solution to wash the spent catalyst and to make a wash slurry having an alkaline pH, wherein the spent catalyst has been in contact with chloroaluminate ionic liquid catalyst, and wherein the spent catalyst comprises from 5 to 35 wt % chloride; and b) filtering the wash slurry and collecting: i) a filter cake having from at least 70 wt % of the chloride in the spent catalyst removed and having the noble metals retained, and ii) a wash filtrate. Also provided is a filter cake comprising a washed consolidated cake having 40 to 75 wt % solids, a cake moisture content from 25 to less than 60 wt %, 0.1 to 1.5 wt % total noble metals, and a residual chloride content of from zero to less than 4 wt %.

First claim

It is claimed:

1 . A filter cake suitable for precious metals recovery, comprising: a washed consolidated cake having a % solids from 40 to 75 wt %, a cake moisture content from 25 to less than 60 wt %, 0.1 to 1.5 wt % total noble metals, and a residual chloride content of from zero to less than 4 wt % that is at least 80 wt % lower than an initial chloride content of a spent noble metal fixed-bed catalyst that had been in contact with a chloroaluminate ionic liquid catalyst and the chloroaluminate ionic liquid catalyst was trapped inside the spent noble metal fixed-bed catalyst.

2 . The filter cake of claim 1 , wherein the washed consolidated cake is not water reactive.

3 . The filter cake of claim 1 , wherein the washed consolidated cake comprises a filter aid.

4 . The filter cake of claim 3 , wherein the filter aid comprises from 50 to 98 wt % silica.

5 . The filter cake of claim 3 , wherein the filter aid is selected from the group consisting of diatomaceous earth, fly ash, perlite, cellulose, calcined rice hull ash, and fibers from used paper products.

6 . The filter cake of claim 5 , wherein the filter aid is calcined rice hull ash.

7 . The filter cake of claim 1 , wherein the washed consolidated cake comprises no aluminum hydroxide colloidal gels.

8 . The filter cake of claim 1 , wherein the cake moisture content is from 30 to less than 50 wt %.

9 . The filter cake of claim 1 , wherein the noble metals comprise platinum group metals.

10 . The filter cake of claim 9 , wherein the platinum group metals comprise platinum, palladium, or a mixture thereof.

Assignees

• Chevron Usa Inc

Inventors

• Bhaduri Rahul Shankar
• Timken Hye Kyung Cho
• Cuspard Phillip Ian

Classifications

• C22B7/009

  General processes for recovering metals or metallic compounds from spent catalysts (for recovering specific metals C22B11/00 - C22B61/00) · CPC title

• C22B11/048 Primary

  from spent catalysts · CPC title

• Y02W30/50

  Reuse, recycling or recovery technologies · CPC title

• Y02P10/20

  Recycling · CPC title

• B01J23/96

  of catalysts comprising metals, oxides or hydroxides of the noble metals · CPC title