阅读说明：本技术 一种从氧化铝载体废催化剂中回收铂族金属的方法 (Method for recovering platinum group metal from waste catalyst of alumina carrier ) 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 2021-09-13 设计创作，主要内容包括：本发明公开了一种从氧化铝载体废催化剂中回收铂族金属的方法,将金属捕集剂、氧化铝载体废催化剂、含钙熔剂、含锰熔剂和还原剂按设定比例混合熔炼,熔炼温度为1250～1400℃,金属相与渣分离后,得到含铂族金属的金属相,实现铂族金属回收；熔炼时,CaO含量按照炉渣组成CaO:Al-(2)O-(3)(质量比)＝0.05～1.0加入含钙熔剂；MnO含量按照炉渣组成MnO范围为5～60％加入含锰熔剂。本发明不含SiO-(2),可解决常规含SiO-(2)渣系高温铁捕集形成硅铁合金的难题,有利于铂族金属回收,铂族金属回收率大于99.5％；本发明选择的渣具有较低的熔化温度,造渣过程加入的钙、锰熔剂少,渣量少,环境友好。(The invention discloses a method for recovering platinum group metals from waste alumina-supported catalysts, which comprises the steps of mixing and smelting a metal trapping agent, the waste alumina-supported catalysts, a calcium-containing flux, a manganese-containing flux and a reducing agent according to a set proportion, wherein the smelting temperature is 1250-1400 ℃, and after the metal phase is separated from slag, the metal phase containing the platinum group metals is obtained, so that the platinum group metals are recovered; during smelting, the content of CaO is determined by the composition of slag CaO and Al 2 O 3 (mass ratio) 0.05-1.0A calcium-containing flux; the MnO content is 5-60% of the MnO content of the furnace slag composition, and a manganese-containing flux is added. The invention does not contain SiO 2 Can solve the problem of the conventional SiO-containing 2 The difficulty of forming ferrosilicon alloy by capturing slag system high-temperature iron is favorable for recovering platinum group metals, and the recovery rate of the platinum group metals is more than 99.5 percent; the slag selected by the invention has lower melting temperature, less calcium and manganese fluxing agents are added in the slagging process, the slag amount is less, and the environment is friendly.)

1. A method for recovering platinum group metals from alumina-supported spent catalysts is characterized in that:

mixing a metal trapping agent, an alumina carrier waste catalyst, a calcium-containing flux, a manganese-containing flux and a reducing agent according to a set proportion, smelting at the smelting temperature of 1250-1400 ℃, separating slag from metal to obtain smelting slag and a metal phase containing platinum group metal, collecting the metal containing platinum group, and realizing platinum group metal recovery.

2. The method of claim 1 for recovering platinum group metals from spent catalysts on alumina supports, characterized in that:

the flux containing calcium and magnesium is any one of lime, limestone, dolomite, quicklime, calcium oxide and calcium carbonate.

3. The method of claim 1 for recovering platinum group metals from spent catalysts on alumina supports, characterized in that:

the manganese-containing flux is manganese oxide or manganese carbonate.

4. The method of claim 2 for recovering platinum group metals from alumina-supported spent catalysts, characterized in that:

the flux containing calcium and magnesium is calcium oxide; during smelting, the amount of calcium oxide added is according to CaO and Al in the smelting slag₂O₃(mass ratio) 0.05-1.0: 1 is added.

5. The method of claim 3, wherein the recovery of platinum group metals from spent catalyst on alumina support is carried out by:

the manganese-containing flux is manganese oxide; during smelting, the manganese oxide is added according to the content of 5-60% of manganese oxide in the smelting slag.

6. The method of claim 4, wherein the recovery of platinum group metals from spent catalyst on alumina support is carried out by:

al in the smelting slag₂O₃The content of the CaO is 40-50%, and the content of the CaO is 2-45%.

7. The method for recovering platinum group metals from alumina-supported spent catalysts according to claim 5 or 6, characterized in that:

al in the smelting slag₂O₃The sum of the contents of CaO and MnO is not less than 90%.

8. The process for recovering platinum group metals from alumina-supported spent catalysts according to any one of claims 1 to 6, characterized in that:

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 an alumina carrier waste 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 generated waste catalyst platinum group metal has huge value and needs to be recycled.

For secondary Al₂O₃The recovery method of the carrier platinum group metal catalyst mainly comprises wet dissolving, pyrometallurgical metal capture method and the like.

The wet method mainly comprises an acid selective dissolution carrier method, a selective dissolution precious metal method and a total dissolution method, and is only suitable for soluble gamma-Al₂O₃The carrier catalyst has low dissolving efficiency, large acid and alkali consumption and high production cost.

The high-temperature smelting metal trapping method in the pyrometallurgical process is characterized in that according to the composition of a platinum group metal catalyst carrier, a trapping agent such as copper oxide and iron oxide, a slagging agent, a reducing agent and the like are added for high-temperature smelting, and the platinum group metals are trapped by utilizing molten metal copper, iron and the like to form an alloy, so that the platinum group metals are effectively enriched and recovered.

Chinese patent (application number: 201510797358.6) discloses that nickel matte is used as a trapping agent, calcium oxide and silicon dioxide are used as slag forming agents, platinum group metals in waste catalysts are trapped by melting at 1400-1450 ℃, wherein nickel is toxic heavy metal and SO is generated in the melting process₂A gas.

Chinese patent application No. 201911145745.6 discloses a method for recovering platinum group metals from waste catalysts of VOCs (volatile organic compounds), and FeS is used as raw material₂As a trapping agent, calcium oxide, sodium carbonate, calcium fluoride, borax and the like are added as slag formers, the smelting temperature is 1000-1700 ℃, and SO is generated in the presence of₂Large amount of gas and slag and the like.

Chinese patent (application number: 201310005494.8) discloses a method for smelting and extracting platinum group metals from alumina-supported petrochemical catalysts, iron and copper are used as collectors, sodium salt is used as a slagging agent, and smelting is carried out at 1100-1450 ℃, but the sodium salt seriously erodes a smelting furnace lining.

Chinese patent (application number: 202011066886.1) discloses a method for extracting palladium from a low-grade ineffective alumina carrier catalyst, wherein the low-grade ineffective alumina carrier catalyst, a reducing agent, a trapping agent iron red, a flux lime, quartz and a binder are made into pellets, and reduction smelting is carried out at 1300-1450 ℃ to obtain a platinum group metal-containing melt.

Chinese patent (application number: 202010835163.7) discloses a method for pyrogenically enriching platinum group metals of aluminum-based waste catalyst by adopting CaO-Al₂O₃-Fe₂O₃-B₂O₃Slag system smelting, wherein the smelting temperature is 1500-1800 ℃, and the problems of high smelting temperature, high energy consumption and the like exist.

Chinese patent (application number: 202010631384.2) publicationA method for designing the slag form of platinum group metal for trapping the used catalyst by iron features that its viscosity is not higher than 0.3Pa.s and its density is not higher than 3X 10³kg/m³However, the slag former needs to be added with sodium salt, borax, calcium fluoride and other substances, which have serious erosion effect on the furnace lining of the smelting furnace, and meanwhile, the viscosity is too low, the slag system flows fast, the physical scouring effect on the furnace lining is strong, and the defect that the service life of the furnace lining of the smelting furnace is short is caused.

The key of the metal trapping method for recovering platinum group metals from the alumina carrier waste catalyst lies in a slagging method, and the analysis shows that the current slagging method cannot effectively reduce the operation difficulty and energy consumption of smelting, and does not well solve the problem of high-efficiency recovery of the platinum group metals.

Disclosure of Invention

The invention aims to solve the technical problems that in the prior art, the reagent consumption is high, the wastewater is difficult to treat, and the temperature is high, the energy consumption is high and the like in a pyrometallurgical smelting metal trapping method in the wet method for recovering platinum group metals from alumina carrier waste catalysts, so that the smelting operation difficulty and the energy consumption are reduced, and the high-efficiency recovery rate of the platinum group metals is realized.

The technical scheme of the invention is as follows:

a method for recovering platinum group metals from alumina-supported spent catalysts, comprising: mixing and smelting a metal trapping agent, an alumina carrier waste catalyst, a calcium-containing flux, a manganese-containing flux and a reducing agent according to a set proportion, wherein the smelting temperature is 1300-1400 ℃, after metal phase and slag are separated, smelting slag and metal phase containing platinum group metal are respectively obtained, and the platinum group metal is collected to realize platinum group metal recovery.

Further, the added calcium-containing flux includes, but is not limited to, lime, limestone, dolomite, quick lime, calcium oxide, calcium carbonate.

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, during smelting, the content of CaO is CaO and Al according to the composition of slag₂O₃(mass ratio) 0.05-1.0 plusAdding a calcium-containing flux; the MnO content is 5-60% of the MnO content of the furnace slag composition, and a manganese-containing flux is added.

Further, the composition of the obtained slag is (Al)₂O₃+ CaO + MnO) system₂O₃The content ranges from 40 to 50 percent, the CaO content ranges from 2 to 45 percent, and the MnO content ranges from 5 to 60 percent.

Further, Al in the produced slag₂O₃The sum of + CaO + MnO is not less than 90%.

Furthermore, the viscosity range of the produced slag at 1250-1400 ℃ is 0.3-0.6 Pa.s.

Further, the metal trapping agent comprises one or more of iron, copper, nickel, lead, tin 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 alloy complement, so that the high-efficiency recovery of the platinum group metals is realized. According to the invention, CaO-Al₂O₃The ternary MnO phase diagram has the characteristic of a larger region with the melting temperature lower than 1400 ℃, a slag phase with a lower melting temperature can be formed, the fluidity is better, and the migration of platinum group metals to a trapped metal phase is facilitated.

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

CaO-Al provided by the invention₂O₃A slag system of MnO based, SiO-free₂Can solve the problem of the conventional SiO-containing₂The difficulty of forming ferrosilicon alloy by capturing slag system high-temperature iron is favorable for recovering platinum group metals, and the recovery rate of the platinum group metals is more than 99.5 percent. CaO-Al provided by the invention₂O₃the-MnO slag system has lower melting temperature (1251 ℃ minimum), and the added calcium-manganese fluxing agent in the slagging process is less, the slag amount is less, and the environment is friendly. The fluxing agent containing calcium and manganese used for slagging of the invention is cheaper than borax and sodium salt, has low cost and good economic benefit, and can protectThe proper viscosity range is maintained, the erosion effect on the furnace lining is reduced, and the service life of the smelting furnace is prolonged.

Drawings

FIG. 1: al (Al)₂O₃CaO-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 iron collector, waste platinum catalyst on alumina carrier, calcium-containing flux, manganese-containing flux and reductant (such as coke) in a predetermined proportion, smelting in an electric furnace, and adding Al₂O₃Adding a calcium-containing flux with the mass ratio of 1.0, adding MnO with the mass fraction of 5%, and separating at 1400 ℃ for 120min to obtain molten iron containing platinum group metal and slag, wherein the recovery rate of Pt is 99.8%.

Example 2

Mixing iron collector, waste palladium catalyst on alumina carrier, calcium containing flux, manganese containing flux and reductant in certain proportion, smelting in an electric furnace in CaO-Al ratio₂O₃Adding a calcium-containing flux into the molten iron according to the mass ratio of 1.0, adding MnO with the mass fraction of 10%, smelting at 1250 ℃, and smelting for 120min, separating to obtain molten iron and slag containing platinum group metals, wherein the recovery rate of Pd is 99.7%.

Example 3

Mixing copper collector, alumina carrier waste platinum catalyst, calcium-containing flux, manganese-containing flux and reducer according to a set proportion, smelting in an electric furnace according to CaO and Al₂O₃Adding a calcium-containing flux into the mixed solution at a mass ratio of 0.4, adding 30% of MnO, melting at 1350 ℃, separating for 120min to obtain a platinum group metal-containing copper metal phase and furnace slag, and achieving a Pt recovery rate of 99.7%.

As shown in figure 1, the ternary eutectic reaction can occur at about 1251 ℃, and as can be seen from figure 1, the phase diagram has the characteristic of a larger melting temperature lower than 1400 ℃, and 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

Dot	Composition of phase	Al2O3/％	MnO/％	CaO/％	Melting temperature/. degree.C
						1	Ca3Al2O6、CaO、MnO	39.18	14.53	46.30	1370.45
2	CaAl2O4、CaAl4O7、MnO	47.34	33.52	19.14	1336.13
						3	CaAl12O19、CaAl4O7、MnO	44.36	52.86	2.78	1290.43
4	Al2O3、CaAl12O19、MnO	44.06	54.60	1.34	1282.78
						5	Ca3Al2O6、CaAl2O4、MnO	44.82	11.22	43.96	1251.40

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.