Method for recovering noble metal from waste alumina carrier noble metal catalyst

Abstract

The invention discloses a method for recovering noble metal from a waste alumina carrier noble metal catalyst, and particularly relates to a method for recovering platinum from a high-carbon-content waste Pt / alpha-Al2O3 catalyst, which mainly comprises the steps of roasting, leaching, noble metal refining and the like. According to the method, sodium carbonate and sodium peroxide are directly added into the waste catalyst for roasting, alpha-Al2O3 is converted into soluble sodium metaaluminate, meanwhile, released carbon dioxide and oxygen are decomposed to promote effective removal of organic matters and carbon deposits, and carrier component transition and removal of the organic matters and carbon are achieved in a same system. In order to avoid hydrolytic precipitation of sodium metaaluminate, a roasted product is leached by adopting a dilute sodium hydroxide solution, the noble metal is enriched in leached residues, and the noble metal is obtained through refining and purification. The method is simple in technological process, easy to implement on a large scale, high in efficiency and low in energy consumption, and the recovery rate of the noble metal is 99% or above.

Description

technical field [0001] The invention belongs to the field of secondary resource recovery of precious metals, and relates to a method for recovering precious metals from waste alumina carrier precious metal catalysts, especially a method for recovering precious metals from waste Pt / α-Al with high carbon content 2 o 3 Process for recovering platinum from catalysts. Background technique [0002] The carrier of precious metal catalysts widely used in petroleum refining and chemical industry is usually alumina, mainly γ-Al 2 o 3 Type and α-Al 2 o 3 type. After the catalyst has been used for a period of time, due to factors such as poisoning, organic coverage, carbon deposition, and noble metal oxidation, the catalyst loses its activity and needs to be replaced regularly. The precious metals in the waste catalysts produced are of great value, and the precious metals in them need to be recycled and reused. For Al 2 o 3 Supported precious metal catalysts, before recycling pr...

AI Technical Summary

Problems solved by technology

For waste catalysts with low carbon content, the decarburization effect is good, and a good recovery rate of precious metals can be obtained; but for waste catalysts with high carbon content, the decarburization effect of roasting is poor, and the recovery rate of precious metals is low.

The existing carrier method and total dissolution method are only suitable for processing soluble γ-Al 2 o 3 Carrier spent catalyst, not suitable for treating α-Al 2 o 3 The spent catalyst of the carrier, and the amount of acid and alkali waste liquid is large; the method of dissolving precious metals is usually used for α-Al 2 o 3 Carrier spent catalyst or γ-Al 2 o 3 Transformation to α-Al 2 o 3 Dissolving again, the solution precious metal concentration obtained is low, and there is a problem that the recovery rate of precious metal is low

The roasting digestion method is to add sodium hydroxide to the waste catalyst for digestion and roasting, the roasted product is easy to agglomerate, and the subsequent treatment is difficult

In the published literature, for the treatment of low carbon content, γ-Al 2 o 3 There are many recovery methods for supported waste precious metal catalysts, but for high carbon content α-Al 2 o 3 There are few reports on the recovery methods of carrier waste precious metal catalysts, and the recovery rate of precious metals in known methods is low