阅读说明：本技术 一种废氧化铝载体铂族金属催化剂的富集方法 (Enrichment method of waste alumina carrier platinum group metal catalyst ) 是由 董海刚 赵家春 吴跃东 崔浩 陈力 段顺飞 童伟锋 王亚雄 吴晓峰 戴华 于 2021-07-01 设计创作，主要内容包括：本发明公开了一种废氧化铝载体铂族金属催化剂的富集方法,主要包括将废氧化铝载体催化剂通过预处理脱除积碳及有机物,然后与熔剂混合制团,再将烘干的团块分成数个等份分批次加入到预先熔融的金属铜熔体中,恒温一段时间,倾倒出熔炼渣后；将另一等份团块继续加入到熔体中,进行熔炼,重复熔炼操作,熔炼结束后,分离出熔炼渣,获得铜-铂族金属合金,实现铂族金属的富集。本发明熔炼温度低,其熔炼渣中铂族金属含小,并且具有工艺简单、易于连续生产等特点。(The invention discloses an enrichment method of a waste alumina carrier platinum group metal catalyst, which mainly comprises the steps of pretreating the waste alumina carrier catalyst to remove carbon deposition and organic matters, mixing the waste alumina carrier catalyst with a flux to prepare a briquette, dividing dried briquettes into a plurality of equal parts, adding the briquettes into a pre-melted metal copper melt in batches, keeping the temperature for a period of time, and pouring out smelting slag; and continuously adding the other equal part of the agglomerates into the melt, smelting, repeating the smelting operation, and separating out smelting slag after the smelting is finished to obtain the copper-platinum group metal alloy so as to realize the enrichment of the platinum group metal. The invention has the characteristics of low smelting temperature, small platinum group metal content in the smelting slag, simple process, easy continuous production and the like.)

1. A method for enriching a platinum group metal catalyst on a waste alumina support, the method comprising:

removing carbon deposition and organic matters from the waste alumina carrier catalyst through pretreatment, mixing the waste alumina carrier catalyst with a flux to prepare agglomerates, dividing dried agglomerates into a plurality of equal parts, adding the equal parts into a pre-melted metal copper melt in batches, keeping the temperature for a period of time, and pouring out smelting slag; and continuously adding the other equal part of the agglomerates into the melt, smelting, repeating the smelting operation, and separating out smelting slag after the smelting is finished to obtain the copper-platinum group metal alloy so as to realize the enrichment of the platinum group metal.

2. The method of enriching a spent alumina supported platinum group metal catalyst as claimed in claim 1, comprising the steps of:

step (1), pre-roasting: grinding the waste alumina carrier platinum group metal catalyst to the granularity of less than 0.2mm, and pre-roasting;

step (2), mixing and briquetting: according to the set composition range of oxides in the smelting slag, mixing the roasted product obtained in the step (1) with SiO₂Mixing CaO, adding water, pressing into a briquette with the diameter of 15-30 mm, and drying;

and (3) smelting and trapping: heating metal copper to a certain temperature for pre-melting, dividing the lumps obtained in the step (2) into a plurality of equal parts, adding the equal parts into a molten metal copper melt in batches, carrying out melting and trapping, keeping the temperature for a period of time, slowly pouring out melting slag, then adding the other part of lumps into the melt for melting, repeating the same melting operation, and separating out the melting slag after the melting is finished to obtain the copper-platinum group metal alloy.

3. The method of enriching a spent alumina supported platinum group metal catalyst of claim 2, wherein:

in the step (1), the waste alumina carrier platinum group metal catalyst isPt/Al₂O₃、Pd/Al₂O₃Any one of the catalysts.

4. The method of enriching a spent alumina supported platinum group metal catalyst of claim 2, wherein:

in the step (1), the pre-roasting temperature is 500-700 ℃, and the roasting time is not less than 1 h.

5. The method of enriching a spent alumina supported platinum group metal catalyst of claim 2, wherein:

in the step (2), the composition range of the smelting slag oxide is as follows: al (Al)₂O₃：15～25％，SiO₂：30～40％，CaO：30～45％。

6. The method of enriching a platinum group metal catalyst on a waste alumina support according to any one of claims 2 to 5, wherein:

in the step (3), the amount of the metal copper is 30-100% of the weight of the waste catalyst.

7. The method of enriching a platinum group metal catalyst on a waste alumina support according to any one of claims 2 to 5, wherein:

in the step (3), the metal copper is heated to a certain temperature, the heating temperature for pre-melting is 1300-1400 ℃, and the constant temperature is kept for a period of time not less than 2 hours.

8. The method of enriching a platinum group metal catalyst on a waste alumina support according to any one of claims 2 to 5, wherein:

in the step (3), the lump obtained in the step (2) is divided into a plurality of equal parts, namely 3-5 equal parts.

Technical Field

The invention belongs to the field of precious metal secondary resource recovery, and relates to an enrichment method of a waste alumina carrier platinum group metal catalyst.

Background

The carrier of platinum group metal catalysts widely used in petroleum refining, chemical industry and the like is usually alumina. After the catalyst is used for a period of time, the catalyst loses activity due to factors such as poisoning, organic matter and carbon deposit coverage, platinum group metal oxidation and the like, and needs to be replaced periodically, and the platinum group metal in the generated waste catalyst has huge value and needs to be recycled. For scrap Al₂O₃The recovery method of the carrier platinum group metal catalyst mainly comprises wet dissolving, reduction smelting metal trapping process and the like.

Patent CN103276215A discloses a method for recovering precious metals from spent catalysts. The method is technically characterized in that the waste catalyst is burnt at 400-800 ℃ to remove carbon deposit and organic matters, sulfuric acid is adopted to pressurize and dissolve the waste catalyst carrier, and TiCl is added₃Solution to prevent dispersion of the noble metal.

Patent CN103194606A discloses a method for enriching platinum group metals from alumina-based spent catalysts, comprising the steps of: A. primary incineration; B. crushing; C. pressurizing and dissolving in alkali; D. filtering; E. and (5) carrying out secondary incineration. The dissolution rate of the alumina is more than 95 percent, and the recovery rate of the platinum group metal is more than 99 percent.

Patent CN107190147A discloses a method for selectively dissolving and recovering platinum from aluminum-based platinum catalyst, which comprises the steps of dissolving waste Pt/gamma-Al₂O₃The catalyst is roasted to remove organic matters and carbon deposition, and simultaneously, the gamma-Al is added₂O₃Transformation to alpha-Al₂O₃Then, platinum is dissolved by oxidation, and the obtained platinum solution is refined, and the recovery rate of the platinum is more than 98.5 percent.

Patent CN112267025A discloses a method for extracting palladium from a low-grade ineffective alumina carrier catalyst, which is to mix and grind the low-grade ineffective alumina carrier catalyst with a reducing agent, iron red, a flux, a binder and water, to prepare pellets, dry the pellets, and perform reduction smelting to obtain a metal melt and smelting slag respectively; atomizing, spraying powder, rusting and gravity separation are carried out on the metal melt to obtain palladium concentrate, palladium powder is obtained after the palladium concentrate is refined, the palladium recovery rate is more than 97.0%, and the palladium content in the palladium powder is more than 99.95%.

Patent CN103014352A discloses a method for smelting and extracting platinum group metals from alumina-supported petrochemical catalysts, which comprises the following process steps: mixing the alumina-supported petrochemical catalyst with a trapping agent, a reducing agent and a slagging agent, and then smelting to trap the noble metal in the mixture to obtain a byproduct and an alloy containing the noble metal; dissolving the obtained alloy containing precious metals by acid to separate precious base metals to obtain precious metal concentrate; and refining the precious metal concentrate to obtain a platinum group metal product. The reduction smelting trapping method adopts metal oxide as a trapping agent to carry out reduction smelting, the smelting temperature is high, the proportion ratio of a slagging agent is high, the slag quantity is large, the smelting time is long, the production continuity is poor, the content of platinum group metals in platinum group metal concentrate is low, and the subsequent treatment is complicated.

The method for recovering platinum group metal from waste alumina carrier platinum group metal catalyst in the prior published documents is mainly a wet process, and has the problems of large waste liquid amount, pollution and the like. The reported high-temperature reduction smelting metal trapping and recovering method has the problems that the selection of a smelting slag type is not proper, metal oxide is used as a trapping agent, reduction smelting is required, the smelting temperature is high, the industrial application feasibility is low, and the like.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide a method for enriching a waste alumina carrier platinum group metal catalyst, which is different from the conventional smelting recovery process, and comprises the steps of mixing the waste catalyst and a flux in proportion to prepare a briquette, then adding the briquette into a pre-molten copper melt in batches for smelting, pouring out upper-layer smelting slag after each batch of smelting is finished, and adding another batch of briquette to repeat the smelting operation.

The technical scheme of the invention is as follows:

a method for enriching a platinum group metal catalyst on a waste alumina support, the method comprising:

removing carbon deposition and organic matters from the waste alumina carrier catalyst through pretreatment, mixing the waste alumina carrier catalyst with a flux to prepare agglomerates, dividing dried agglomerates into a plurality of equal parts, adding the equal parts into a pre-melted metal copper melt in batches, keeping the temperature for a period of time, and pouring out smelting slag; and continuously adding the other equal part of the agglomerates into the melt, smelting, repeating the smelting operation, and separating out smelting slag after the smelting is finished to obtain the copper-platinum group metal alloy so as to realize the enrichment of the platinum group metal.

Specifically, the method for enriching the waste alumina carrier platinum group metal catalyst comprises the following steps:

step (1), pre-roasting: finely grinding the waste alumina carrier platinum group metal catalyst to the granularity of less than 0.2mm, and pre-roasting;

step (2), mixing and briquetting: according to the set composition range of the oxides of the smelting slag, the roasted product obtained in the step (1) and SiO₂Mixing CaO, adding water, pressing into a briquette with the diameter of 15-30 mm, and drying;

and (3) smelting and trapping: heating metal copper to a certain temperature for pre-melting, dividing the lumps obtained in the step (2) into a plurality of equal parts, adding the equal parts into a molten copper melt in batches, smelting, preserving heat for a period of time, and slowly pouring out smelting slag; and then adding the other part of the agglomerate into the melt for smelting, repeating the same smelting operation, and separating out smelting slag after the smelting is finished to obtain the copper-platinum group metal alloy.

Further, the platinum group metal catalyst on the waste alumina carrier isPt/Al₂O₃、Pd/Al₂O₃And the like.

Preferably, in the step (1), the pre-roasting temperature of the waste alumina carrier platinum group metal catalyst is 500-700 ℃, and the roasting time is not less than 1 h.

Preferably, in the step (2), the composition range of the oxides of the smelting slag is as follows: al (Al)₂O₃：15～25％，SiO₂：30～40％，CaO：30～45％；

Preferably, in the step (3), the amount of the metal copper is 30-100% of the weight of the waste catalyst; the heating temperature is 1300-1400 ℃, and the constant temperature time is not less than 2 h; the lumps are divided into a plurality of equal parts which are divided into 3-5 equal parts.

The mechanism and the beneficial effects of the invention are mainly as follows:

1) the pre-roasting treatment removes carbon deposition and organic matters, thereby avoiding the generation of reducing substances in the subsequent smelting process.

2) Based on the phase diagram analysis of the smelting slag, Al is reasonably arranged₂O₃-SiO₂The smelting slag system comprises oxides, the melting temperature of the smelting slag is kept at 1300-1400 ℃, and the smelting slag has good fluidity, so that the capturing effect of the copper liquid on platinum group metals and the separation of the smelting slag phase and the metal phase are improved;

3) the invention is different from the conventional smelting process in that a waste catalyst and a flux are mixed in proportion to prepare a briquette, then the briquette is added into a pre-molten copper melt in batches to be smelted, after each batch of smelting is finished, the upper-layer smelting slag is poured out, and then another batch of briquette is added to repeat the smelting operation; the molten metal has a large phase quantity in each batch of smelting process, so that the copper metal can trap trace platinum group metals; the smelting temperature adopted by the invention is low, and the platinum group metal content in the smelting slag is less than 10 g/t.

4) The invention has simple process flow and is easy for industrial continuous production.

Detailed Description

The examples used raw materials and main auxiliary materials:

waste catalyst: Pt/Al₂O₃Catalyst Pd/Al₂O₃A catalyst from a chemical company;

silica, calcium oxide, metallic copper: are all of industrial grade.

Example 1

3kg of waste Pt/Al is taken₂O₃Catalyst (C2.6%, Al)₂O₃96.8% of Pt 4430g/t) are ground to below 0.2mm, calcined at 600 ℃ for 2h, cooled and then mixed with 5.38kg of SiO₂5.52kg of CaO, adding water for wetting, pressing into a briquette with the diameter of 20mm by a ball press, drying and dividing into three equal parts; heating 2kg of metal copper to 1400 ℃ for pre-melting, slowly adding the first equal part of the dried agglomerate into molten copper liquid through a feed inlet, preserving heat for 2 hours after the addition of the material, and slowly pouring out the upper-layer smelting slag; continuing to slowly add the second half block mass into the melt, preserving heat for 2 hours after the addition of the second half block mass is finished, and slowly pouring out the upper-layer smelting slag; and slowly adding the third equal part of the block masses into the melt, keeping the temperature for 2 hours after the addition, slowly pouring out the upper-layer smelting slag, cooling, completely separating the smelting slag from the metal phase to obtain a platinum-copper alloy, combining the three sections of the smelting slag, sampling and analyzing, and obtaining the platinum content in the smelting slag of 9.4 g/t.

Example 2

3kg of waste Pd/Al is taken₂O₃Catalyst (C32.8%, Al)₂O₃66.9 percent of Pd 1530g/t) is ground to be less than 0.2mm, roasted for 3 hours at the temperature of 700 ℃, cooled and mixed with 5kg of SiO₂5kg of CaO, adding water for wetting, pressing into a briquette with the diameter of 20mm by a ball press, drying and dividing into three equal parts; heating 1kg of metal copper to 1350 ℃, adding the first equal part of the dried agglomerate into molten copper slowly through a feed inlet, keeping the temperature for 3 hours after adding the material, and pouring out the upper-layer smelting slag slowly; continuing to slowly add the second half block mass into the melt, preserving heat for 3 hours after the addition of the second half block mass is finished, and slowly pouring out the upper-layer smelting slag; slowly adding the third equal amount of block mass into the melt, keeping the temperature for 3h after the addition of the block mass is finished, slowly pouring out the upper-layer smelting slag, cooling, and completely separating and smeltingSlag and metal phase to obtain palladium-copper alloy; and combining the three sections of smelting slag, sampling and analyzing, wherein the palladium content in the smelting slag is 5.4 g/t.