Metallurgical Extraction Technique To Recover Platinum Group Metals From A Filter Cake (Chevron)

CATEGORY: CATALYSIS: PRECIOUS METALS RECOVERY 
Metallurgical Extraction Technique To Recover Platinum Group Metals From A Filter Cake (Chevron)
United States Patent Application 20160115567
Bhaduri; Rahul Shankar ;   et al.   April 28, 2016
Assignee: Chevron U.S.A.
Abstract
This application provides a metallurgical extraction technique, comprising: a) re-pulping a feed filter cake to make a filter cake slurry; b) grinding the filter cake slurry; c) leaching the ground filter cake slurry in a hot alkaline cyanide solution to provide dissolved platinum group metals; d) liquid-solid separating of the dissolved platinum group metals; and e) recovering the dissolved platinum group metals by cementing the dissolved platinum group metals with a precipitating metal comprising an aluminum or a zinc; wherein the feed filter cake has the platinum group metals at a total amount from 0.1 to 1.5 wt % and a halide anion content from zero to less than 4 wt %. This application provides a process for platinum group metal recovery, comprising: converting a catalyst which was in contact with a water reactive ionic liquid catalyst into a non-water reactive filter cake and extracting the platinum group metals.
[0001] This application is related to a co-filed application, titled "PROCESS FOR PREPARING A SPENT CATALYST FOR PRECIOUS METALS RECOVERY", herein incorporated in its entirety.
TECHNICAL FIELD
[0002] This application is directed to metallurgical extraction techniques including grinding, leaching, and cementing to recover platinum group metals from a filter cake.
BACKGROUND
[0003] Improved processes for recovering platinum group metals from filter cakes are needed.
SUMMARY
[0004] This application provides a metallurgical extraction technique, comprising:
[0005] a) re-pulping a feed filter cake to make a filter cake slurry;
[0006] b) grinding the filter cake slurry to make a ground filter cake slurry;
[0007] c) leaching the ground filter cake slurry in a hot alkaline cyanide solution to provide dissolved platinum group metals;
[0008] d) liquid-solid separating of the dissolved platinum group metals; and
[0009] e) recovering the dissolved platinum group metals by cementing the dissolved platinum group metals with a precipitating metal comprising an aluminum or a zinc to make a cemented filter cake; wherein the feed filter cake has the platinum group metals at a total amount from 0.1 to 1.5 wt % and a halide anion content from zero to less than 4 wt %.
[0010] This application also provides a process for platinum group metal recovery, comprising: converting a platinum group metal-containing solid catalyst which was in contact with a water reactive ionic liquid catalyst into a non-water reactive filter cake and extracting the platinum group metals from the non-water reactive filter cake.
[0011] The present invention may suitably comprise, consist of, or consist essentially of, the elements in the claims, as described herein.
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