阅读说明：本技术 一种从失效汽车催化剂中回收铂族金属的方法 (Method for recovering platinum group metal from spent automobile 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 2021-07-29 设计创作，主要内容包括：本发明公开了一种从失效汽车催化剂中回收铂族金属的方法,将金属捕集剂、失效汽车催化剂、含锰熔剂、含镁熔剂、还原剂按设定比例混合熔炼,冶炼温度为1200～1400℃,金属相和熔炼渣分离后,得到含铂族金属的金属相,实现铂族金属回收；熔炼时,按照炉渣体系中SiO-(2)含量范围为25～45％,Al-(2)O-(3)含量范围为15～25％,MgO含量范围为10～20％,MnO含量范围为20～45％,加入含镁、含锰熔剂。本发明的熔炼渣熔化温度低,不添加对炉衬具有严重侵蚀作用的物质,有利于铂族金属回收；加入的镁锰助熔剂少,渣量少,环境友好；采用的含镁及含锰的熔剂,相对于硼砂、钠盐等价格便宜,铂族金属回收率高。(The invention discloses a method for recovering platinum group metals from a spent automobile catalyst, which comprises the steps of mixing and smelting a metal trapping agent, the spent automobile catalyst, a manganese-containing flux, a magnesium-containing flux and a reducing agent according to a set proportion, wherein the smelting temperature is 1200-1400 ℃, and a metal phase containing the platinum group metals is obtained after the metal phase is separated from smelting slag, so that the platinum group metals are recovered; during smelting, according to SiO in a slag system 2 The content range is 25-45%, and Al 2 O 3 The content ranges from 15 to 25 percent, the MgO content ranges from 10 to 20 percent, the MnO content ranges from 20 to 45 percent, and a flux containing magnesium and manganese is added. The smelting slag has low melting temperature, does not add substances which have serious erosion effect on a furnace lining, and is beneficial to the recovery of platinum group metals; the added magnesium-manganese fluxing agent is less, the slag amount is less, and the environment is protected; the flux containing magnesium and manganese is cheap relative to borax and sodium salt, and the recovery rate of platinum group metal is high.)

1. A method for recovering platinum group metals from spent automotive catalysts,

mixing and smelting a metal trapping agent, a spent automobile catalyst, a manganese-containing flux, a magnesium-containing flux and a reducing agent according to a set proportion, wherein the smelting temperature is 1200-1400 ℃, separating slag from gold to obtain a metal phase containing platinum group metal and smelting slag, and collecting the metal phase containing the platinum group metal to realize platinum group metal recovery.

2. The method as claimed in claim 1, wherein during the mixed smelting according to the set proportion, a magnesium-containing flux is added according to the requirement of 10-20% of MgO content in the slag.

3. The method of claim 1, wherein a manganese-containing flux is added according to the requirement of 20-45% of MnO content in slag during the mixed smelting according to the set proportion.

4. A method according to claim 2 or 3, characterized in that the slag produced is SiO-SiO₂、Al₂O₃The sum of the contents of MgO and MnO is not less than 90%.

5. A method according to claim 1 or 2, wherein the magnesium-containing flux is any one of dolomite, magnesium oxide, magnesium carbonate.

6. A method according to claim 1 or claim 3, wherein the manganese-containing flux is manganese oxide or manganese carbonate.

7. The method according to claim 2 or 3, wherein the smelting time is 90-120 min.

8. The method of claim 4, wherein the SiO in the slag₂25-45% of Al₂O₃The content is 15-25%.

9. The method of any one of claims 1 to 3, wherein the spent automotive catalyst is a cordierite-supported spent automotive catalyst.

10. The method of any one of claims 1 to 3, wherein the metal trapping agent comprises: one or more of iron, copper, nickel, antimony, lead, or one or more of iron, copper, nickel, antimony, lead alloys.

Technical Field

The invention belongs to the field of platinum group metal recycling, and particularly relates to a method for recycling platinum group metals from a spent automobile catalyst.

Background

The platinum group metal has excellent physical and chemical properties such as high stability, high temperature resistance, good catalytic activity and the like, and is widely applied to the fields of automobiles, petroleum, chemical engineering, aerospace and the like. But the platinum group metal reserves are small, the use amount is large, the external dependence is high, and the contradiction between supply and demand is very prominent. Due to cordierite (Mg)₂Al₄Si₅O₁₈) The material has good fire resistance and low thermal expansion rate, and is generally used as a honeycomb carrier material of an automobile exhaust purification catalyst. The spent automobile catalyst is one of important secondary resources of platinum group metals, the recovery of the platinum group metals from the spent automobile catalyst is carried out, the resource recycling is realized, and the method is a necessary choice for solving the problems of serious shortage of platinum group metal mineral resources and outstanding contradiction between supply and demand in China.

The existing method for recovering the waste platinum group metal catalyst from the failed automobile catalyst mainly comprises a wet process (a normal pressure dissolution method, a pressure cyanidation method and the like) and a fire process (a lead capture method, a copper capture method, a sulfonium capture method, a plasma smelting iron capture method, a chlorination method and the like).

The wet process generally dissolves the active components of the platinum group metals, and the platinum group metals are recovered through subsequent refining, so that the recovery rate of the platinum group metals is low, a large amount of waste liquid is generated, the environment is seriously polluted, and the environmental protection problem is prominent; the principle of the pyrometallurgical metal trapping method, such as copper trapping method and iron trapping method, is that according to the composition of platinum group metal catalyst carrier, copper oxide, iron oxide and other trapping agents, slag former, reducing agent and the like are added for high-temperature smelting, and the molten metal copper, iron and other trapping metal platinum group metals are utilized to form alloy, so that the effective enrichment and recovery of the platinum group metals are realized. The recovery of platinum group metals by a high-temperature smelting metal-capturing method has been industrially practiced by companies such as noble metals in Japan, Youme, Belgium, and the like.

The catalyst for treating the invalid automobile exhaust by the pyrogenic process has high treatment capacity, less waste water and gas and high recovery rate of platinum group metals, but has higher technical requirements, and the selection of a slagging method in the smelting process is the key for realizing the high-efficiency recovery of the platinum group metals.

Chinese patent application CN03818803.1 and Chinese application CN200480006344.8 mention that materials containing platinum group metals, copper oxide, solid carbon and flux are put into a closed electric furnace to be smelted for 5-10 hours at the temperature of 1200-1500 ℃, the platinum group metals are enriched in molten metal copper, and the oxide range in the smelting slag selected by the method is Al₂O₃：20～40％，SiO₂：5～40％，CaO：20～35％，FeO：0～35％。

There are documents that propose the recovery of platinum group metals by copper capture method, and the slag forms selected during smelting are CaO and Al₂O₃、SiO₂MgO quaternary system smelting slag type.

The slagging method in the existing pyrogenic recovery process of the spent automobile catalyst usually selects the slag containing CaO and Al₂O₃、SiO₂The quaternary or quinary slag of oxides such as MgO, FeO and the like has the problems of high smelting temperature, poor fluidity of smelting slag, large slag quantity, long smelting time, low production efficiency, higher cost and the like.

Disclosure of Invention

The invention aims to solve the technical problem of providing a recovery method which can effectively reduce the difficulty and energy consumption of smelting operation and realize the green, low-cost, less slag and high recovery rate of platinum group metals aiming at the defects of the existing method for recovering the platinum group metals from the invalid automobile catalyst.

The technical scheme of the invention is as follows:

a method for recovering platinum group metals from a failed automobile catalyst comprises the steps of mixing and smelting a metal trapping agent, the failed automobile catalyst, a manganese-containing flux, a magnesium-containing flux and a reducing agent according to a set proportion, wherein the smelting temperature is 1200-1400 ℃, after a metal phase and slag are separated, a metal phase containing the platinum group metals and smelting slag are respectively obtained, and the platinum group metal phase is collected to realize platinum group metal recovery.

Further, during smelting, according to SiO in a slag system₂The content ranges from 25 to 45 percent, and Al₂O₃The content ranges from 15 to 25 percent, the MgO content ranges from 10 to 20 percent and the MnO content ranges from 20 to 45 percent, and a flux containing magnesium and manganese is added.

Further, in the produced Slag (SiO)₂+Al₂O₃+ MgO + MnO) of not less than 90%.

Furthermore, the failure automobile catalyst is cordierite carrier failure automobile catalyst.

Further, magnesium-containing fluxes added include, but are not limited to, dolomite, magnesium oxide, magnesium carbonate, and the like.

Further, the manganese-containing flux added includes, but is not limited to, manganese oxide, manganese carbonate; the reductant includes, but is not limited to, coke.

Further, the metal trapping agent comprises one or more of iron, copper, nickel, antimony, lead and the like and alloys thereof.

The principle of the invention is as follows:

the technical and economic indicators of the pyrometallurgical high-temperature smelting process are closely related to the properties of the smelting slag, such as melting temperature, pH value, viscosity, surface (interface) tension and density and platinum group metal distribution coefficient. The slag with proper viscosity at lower melting temperature can promote platinum group metals to enter the alloy for trapping, so that the platinum group metals can be efficiently recovered. According to the invention, SiO₂-Al₂O₃The phase diagram of-MgO-MnO series is eutectic reaction at about 1094 deg.C, and the phase diagram has the characteristic of larger melting temperature lower than 1400 deg.C, and can be formed into a structure withThe slag phase with lower melting temperature has better fluidity and is beneficial to the migration of platinum group metals into the trapping agent.

Compared with the prior art, the invention has the beneficial effects that:

the SiO provided by the invention₂-Al₂O₃the-MgO-MnO slag system has low melting temperature, does not add substances such as sodium salt and calcium fluoride which have serious erosion effect on a furnace lining, and is beneficial to the recovery of platinum group metals. The magnesium-manganese fluxing agent added in the slagging process is less, the slag amount is less, and the environment is friendly. The flux containing magnesium and manganese adopted in the invention during slagging is cheaper than borax and sodium salt, and has low cost and good economic benefit. The invention can form a slag phase with lower melting temperature, has better fluidity, is beneficial to the migration of platinum group metals into the trapping agent, has a platinum group metal recovery rate of more than 99.5 percent and has high recovery rate.

Drawings

FIG. 1: al (Al)₂O₃SiO in an amount of 20%₂-MgO-MnO phase diagram.

Detailed Description

The following examples further illustrate embodiments of the present invention, but the embodiments of the present invention are not limited to the following examples.

Example 1

Mixing copper trapping agent, dead automobile catalyst containing Pt, Pd and Rh, flux containing Mg, flux containing Mn and reductant (coke) in certain proportion, smelting in electric furnace to obtain SiO in smelting slag system₂45% of Al₂O₃The content is 15%, the MgO content is 10%, the MnO content is 30%, the melting temperature is 1300 ℃, the time is 120min, the platinum group metal-containing copper alloy and the furnace slag are obtained through separation, and the recovery rates of Pt, Pd and Rh are 99.6%, 99.8% and 99.5%.

Example 2

Mixing copper trapping agent, dead automobile catalyst containing platinum, palladium and rhodium, flux containing magnesium, flux containing manganese and reducing agent in a set proportion, smelting in an electric furnace, and smelting SiO in a slag system₂35% of Al₂O₃The content is 20 percent, and the content of MgO is10 percent, the MnO content is 35 percent, the smelting temperature is 1250 ℃, the smelting time is 120min, the platinum group metal-containing copper alloy and the furnace slag are obtained through separation, and the recovery rates of Pt, Pd and Rh are 99.7 percent, 99.7 percent and 99.4 percent.

Example 3

Mixing iron trapping agent, spent automobile catalyst containing platinum, palladium and rhodium, flux containing magnesium, flux containing manganese and reducing agent according to a set proportion, smelting in an electric furnace, and smelting SiO in a slag system₂30% of Al₂O₃The content is 25 percent, the MgO content is 15 percent, the MnO content is 30 percent, the smelting temperature is 1400 ℃, the smelting time is 90min, the ferroalloy containing platinum group metals and furnace slag are obtained by separation, and the recovery rates of Pt, Pd and Rh are 99.8 percent, 99.8 percent and 99.6 percent.

As shown in figure 1, the eutectic reaction can occur at about 1094 ℃, and the characteristic that the phase diagram has a larger area with the melting temperature lower than 1400 ℃ can be seen from the figure, so that a slag phase with a lower melting temperature can be formed. The slag phase composition and melting temperature are shown in table 1.

TABLE 1 slag phase composition and melting temperature

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.