CN115612855A

CN115612855A - Method for recovering metal platinum from platinum-containing waste catalyst

Info

Publication number: CN115612855A
Application number: CN202110797796.8A
Authority: CN
Inventors: 谷育英; 张小工; 杨柏平; 魏永福; 魏鸿林
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-07-14
Filing date: 2021-07-14
Publication date: 2023-01-17

Abstract

The invention provides a method for recovering metal platinum from a platinum-containing waste catalyst. The recovery method adopts a hydrochloric acid-air oxidation method, dissolves more than 99 percent of Pt in the catalyst by using low-concentration acid, and has the advantages of environmental protection, high recovery rate, small loss, low energy consumption and high product quality. And the produced waste liquid can be used as a water purifying agent, and multiple verification in the embodiment proves that the method is effective and reliable, and a new method is provided for recovering the metal platinum.

Description

Method for recovering metal platinum from platinum-containing waste catalyst

Technical Field

The invention belongs to the field of catalyst recovery treatment, and particularly relates to a method for recovering metal platinum from a platinum-containing waste catalyst.

Background

Among the platinum group metal catalysts, the platinum catalyst has been used in the largest amount for a long time, and has the widest application range, and the active component of the platinum catalyst can be single platinum, or binary or multi-component catalyst which is mainly composed of platinum and is supplemented by other noble metals, transition metals, rare earth metals and the like. It has good activity to hydrogenation, oxidation, dehydrogenation and hydrogenation decomposition reactionsThe most used amount is carrier supported platinum catalyst, in particular Al ₂ O ₃ A platinum or platinum rhenium petroleum reforming catalyst as a carrier. The catalysts still retain precious metals such as platinum and the like after being discarded, have high recovery value, and the recovery of the catalysts needs to be firstly burnt to remove carbon deposit at present, but also causes the loss of the precious metals such as platinum and the like, so that a new method for recovering the platinum in the discarded catalysts is needed to be developed.

Disclosure of Invention

In order to improve the technical problem, the invention provides a method for recovering metal platinum from a platinum-containing waste catalyst, which comprises the following steps:

s1) adding hydrochloric acid into a Pt-containing waste catalyst, stirring and heating, introducing air for oxidation reaction to obtain a reaction solution, and filtering to obtain leaching residues and a leaching solution;

s2) adding iron into the leachate for replacement reduction to obtain mother liquor and metal Pt.

According to an embodiment of the invention, the method comprises the steps of:

s0) sieving the Pt-containing waste catalyst to obtain a filler and the sieved Pt-containing waste catalyst;

s1) adding hydrochloric acid into the sieved Pt-containing waste catalyst, stirring and heating, introducing air for oxidation reaction to obtain a reaction solution, and filtering to obtain leaching residues and a leaching solution;

s2) adding iron into the leaching solution for replacement reduction to obtain mother liquor and metal Pt.

According to an embodiment of the present invention, the Pt-containing spent catalyst may be a Pt-containing reforming catalyst, for example, pt/Al, in step S0) and step S1) ₂ O ₃ A reforming catalyst.

According to an embodiment of the present invention, in step S0), the packing material may be further washed with hydrochloric acid, and a washing solution may be incorporated into the leachate described in step S1).

According to an embodiment of the invention, in step S1), the mass of spent catalyst or spent catalyst after sieving and the volume ratio of hydrochloric acid are 1 (0.5 to 20) kg/L, for example 1 (2 to 8) kg/L, exemplified by 1.

According to an embodiment of the invention, in step S1), the hydrochloric acid has a concentration of 1 to 8mol/L, for example 1 to 4mol/L, exemplarily 1mol/L, 1.5mol/L, 2mol/L, 2.5mol/L, 3mol/L, 3.5mol/L, 4mol/L, 5mol/L, 6mol/L, 7mol/L or 8mol/L.

According to an embodiment of the invention, in step S1), the temperature of the reaction is in the range of 40 to 120 ℃, for example 60 to 100 ℃, exemplary 70 ℃, 80 ℃, 90 ℃.

According to an embodiment of the invention, in step S1), the reaction time is 1 to 24h, for example 2 to 12h, exemplarily 4h, 5h, 6h, 7h, 8h, 9h, 10h.

According to an embodiment of the invention, in step S1), the leach residue may be further washed with hydrochloric acid and the washing solution may be incorporated into the leach solution described in step S1).

According to an embodiment of the invention, in step S2), the ratio of the mass of iron to the volume of the leachate is between 20 and 300g/L, for example between 50 and 200g/L, exemplarily 80g/L, 100g/L, 120g/L, 150g/L.

According to an embodiment of the invention, in step S2), the iron is added in the form of iron flakes.

According to an embodiment of the present invention, step S2) is specifically: adding iron into the leachate for replacement reduction to obtain mother liquor and crude metal Pt, wherein the mother liquor can be used as a water purifying agent after being concentrated, and the crude metal Pt can be further refined and purified to obtain the metal Pt.

According to an embodiment of the invention, in step S2), the purity of the metal Pt is greater than or equal to 99%, such as greater than or equal to 99.5%, for example greater than or equal to 99.9%, for example greater than or equal to 99.95%.

Advantageous effects

The recovery method of the invention adopts hydrochloric acid, preferably can adopt low-concentration (less than or equal to 3 mol) hydrochloric acid for dissolution, and has the advantages of environmental protection, low consumption and high quality.

The method of the invention mainly has the following advantages:

1. 99% of Pt in the catalyst can be dissolved by adopting a hydrochloric acid-air oxidation method;

2. the recovery rate is high, the loss rate of Pt is low, and the recovery rate is improved by 2% compared with the recovery rate in the same industry;

3. the produced waste liquid can be used as a water purifying agent after being concentrated, so that the environmental pollution is reduced;

4. the method can be used for recovering various Pt-containing waste catalysts.

Drawings

FIG. 1 is a process flow diagram for recovering platinum metal according to the present invention.

FIG. 2 is a flow chart of the refining and purification process after crude platinum is obtained in example 1.

Detailed Description

The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

Example 1

1. And (3) sieving the platinum-containing waste catalyst to obtain a porcelain filler and the sieved waste catalyst, washing each kilogram of porcelain filler with 0.6L of hydrochloric acid, and merging the washed solution into the leaching solution 2.

2. 50kg of the sieved waste catalyst is placed in a reaction kettle (500L), and 9mol/L hydrochloric acid is added to solidify (waste catalyst): solution (hydrochloric acid) =1, stirring for reaction, heating to 80-90 ℃, introducing air for oxidation for 6 hours, cooling for 2 hours to obtain reaction solution, and filtering the reaction solution to obtain leaching residue and leaching solution 2.

3. The leached residue is washed with water repeatedly, and the washing liquid is combined with the leached liquid 2.

4. Adding Fe sheets (100 g of iron sheets are added in each liter of leachate) into the leachate 2 for replacement reduction to obtain mother liquor and crude Pt, refining and purifying the crude Pt by a conventional method (see figure 2) to obtain a metal Pt product, wherein various indexes of the recovered platinum are shown in table 1.

5. The mother liquor is concentrated to be used as a water purifying agent.

Examples 2 to 4

Examples 2-4 were carried out in exactly the same manner as in example 1, and the effectiveness and reliability of the method of the present invention was repeatedly demonstrated, and the indices of platinum recovered in each example are shown in Table 1.

Examples 5 to 6

Referring to example 1, except that the mass of the spent catalyst after sieving was 80kg, indexes of recovered platinum are shown in Table 1.

The indices of platinum recovered in examples 1-6 are shown in table 1 below:

TABLE 1

Examples	Throughput (kg)	Grade (%)	Amount of Pt (g)	Yield metal quantity (g)	Recovery (%)
						1	50	0.35	175	174	99.4
2	50	0.35	175	173.5	99.4
						3	50	0.35	175	174.2	99.5
4	50	0.35	175	174.4	99.4
						5	80	0.35	280	278.2	99.4
6	80	0.35	280	277.6	99.4

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recovering metal platinum from a platinum-containing spent catalyst, the method comprising the steps of:

2. Method according to claim 1, characterized in that it comprises the following steps:

3. The method according to claim 1 or 2, wherein the Pt-containing spent catalyst is a Pt-containing reforming catalyst, such as Pt/Al ₂ O ₃ A reforming catalyst.

Preferably, in step S0), the packing material may be further washed with hydrochloric acid, and a washing solution may be combined into the leachate described in step S1).

4. The method according to any one of claims 1 to 3, wherein in step S1), the volume ratio of the mass of the Pt-containing spent catalyst or the sieved Pt-containing spent catalyst to the hydrochloric acid is 1 (0.5 to 20) kg/L, such as 1 (2 to 8) kg/L.

5. The method according to any one of claims 1 to 4, wherein the concentration of hydrochloric acid in step S1) is 1 to 8mol/L, such as 1 to 4mol/L.

6. The process according to any one of claims 1 to 5, wherein in step S1), the temperature of the reaction is between 40 and 120 ℃, such as between 60 and 100 ℃;

preferably, in step S1), the reaction time is 1 to 24 hours, for example 2 to 12 hours.

7. The process according to any one of claims 1 to 6, wherein in step S1) the leach residue is further washed with hydrochloric acid and the washing solution is combined with the leach solution in step S1).

8. The process according to any one of claims 1 to 7, wherein in step S2) the ratio of the mass of iron to the volume of leachate is between 20 and 300g/L, for example between 50 and 200g/L

Preferably, in step S2), the iron is added in the form of iron flakes.

9. The method according to any one of claims 1 to 8, wherein step S2) is in particular: adding iron into the leachate for replacement reduction to obtain mother liquor and crude metal Pt, concentrating the mother liquor to be used as a water purifying agent, and further refining and purifying the crude metal Pt to obtain the metal Pt.

10. The method according to any one of claims 1 to 9, wherein the purity of the metal Pt in step S2) is 99% or more.