Cerium extraction method. RU patent 2495147.

FIELD: metallurgy.

SUBSTANCE: cerium extraction is performed after preliminary preparation of a catalyser. Crushing of the used catalyser is performed. Crushed catalyser is subject to annealing at the temperature of 650-800°C during 3-6 hours. After annealing the catalyser is cooled down to room temperature and cerium compound is extracted by dilution of ignited catalyser in concentrated hydrochloric acid. Obtained solution with suspended particles of cerium dioxide is heated to boiling, exposed at boiling temperature of 100-110°C during 30-120 minutes and during 3-12 hours at temperature of 0-20°C so that a deposition is obtained. The obtained deposition is separated from mother solution by means of filtration by draining the solution from the deposition surface to a filter with the size of filtering material pores of not more than 2 mcm. Deposition on the filter is washed from iron compound and dried till constant weight of cerium dioxide.

EFFECT: extraction of cerium with high purity by eliminating mutual influence of extracted components on each other.

2 cl, 1 dwg, 1 tbl, 11 ex

The present invention relates to the chemical industry, namely to a method of processing of the fulfilled catalysts for dehydrogenation of olefinic hydrocarbons, or other materials of a similar composition to the extraction of valuable components - cerium. The resulting ceria can be used either in the production of catalysts as initial substances, either as individual reagent in other industries.

Spent catalysts are industrial waste, often containing in its composition of the substances possessing a strong toxic effect on the environment. Such elements can be oxides of transition and rare earth elements. A large part of used catalysts exposed simple disposal, which is dangerous and unprofitable, both ecological and economic terms. Spent catalysts are a valuable resource that causes simple disposal; in addition, for neutralization (reducing the toxicity of waste) many catalysts require special technology, as well as specially equipped polygons, equipment costs are very high. All of this indicates that recycling of spent catalysts or recycling are important task.

Modern catalysts for dehydrogenation of olefinic hydrocarbons on chemical and phase composition can be attributed to the most complex in the processes of organic synthesis. Their main component is α-Fe 2 O 3 , the original content of which is 55-85% of the mass. Another indispensable component is any connection potassium (K 2 O K 2 CO 3 ), the concentration of which is 2-20% of the mass, in terms of The 2 PU As promoters are oxides of transitive and rare - earth elements-molybdenum to 2.5%, tungsten, vanadium, manganese, cerium (5-60% of the mass in the form of carbonates, oxides, nitrates and hydroxides) and Nickel. The most expensive of the promoters is cerium, as the share of its compounds account for about 55% of the cost of the catalyst, therefore the primary task is to extract exactly this component.

There is a method of allocating cerium [Application of the Russian Federation 2000122097 A, IPC 7 C01F 17/00, C01G 56/00, G21C 19/46, publ. 20.08.2002], in which the selection is carried out on the solutions of irradiated materials, including extraction of cerium (IV) or (IV) solution D2EGFK and reextraction their solutions, before cerium or in the organic phase was injected simple saturated alcohols, to the concentration of providing completeness recovery cerium or , next their nitric acid (about 2 mol/l), not containing a reducing agent. Disadvantages of this method are the use of organic solvents that are toxic, and the inability to use it because of the different nature of the recoverable items from a mixture of ions in the catalyst in accordance with the invention.

There is a method of allocating cerium [EN 2373299 C1, IPC C22B 59/00, B03D 1/00, publ. 20.11.2009], which concerns producing pure rare-earth metals (REM) or their oxides of poor or technogenic raw materials by the method of ion flotation. Method of extraction of cerium ions and yttrium from the solution includes ionic flotation using as a collector surface-active substances. As a collector of use sodium dodecylsulfate in concentration corresponding to -metric reaction: Me+3+3DS-=Me[DS]3 where IU+3 - cation cerium or yttrium, DS - -ion. For selective extraction of yttrium and separation of ions of yttrium and cerium ionic flotation is carried out at pH=5. The technical result is the increase of the percentage of extraction and separation of cerium ions and yttrium.

Also known way to separate compounds from cerium compounds , alkaline metals and alkaline-earth metals, of lanthanides and actinides, Fe, Zr, Nb [GB 1282827, C01F 17/00, publ. 1972-07-26], by applying liquid aqueous solution, led to a 2-6 molar concentration of nitric acid, which has a sufficient number of bromate to support the CE able CE +4 , through the organic phase (for example, xylene)containing nitrate Quaternary amine formula R 4 NNO 3 , where R 4 denotes 4 alkyl Deputy 1-10 of carbon atoms, where Quaternary salts have a molecular weight of not more than 450, and further selective deletion of cerium the organic phase using agent, chosen among the distilled water, nitric acid or hydrochloric acid.

There is a method of allocating cerium of spent catalyst used in cars [Japan Patent 166260 A, B01J 38/00; B09B 3/00; C01F 17/00; C22B 59/00, publ., 1993.12.09], the essence of which is that the spent catalysts containing precious metals, such as Pt, Rh and Behold, crushed to powder form, after which the powder type in water containing hydrochloric acid, and then add hydrogen peroxide solution obtained interfere when heated. Then, the solution add 4% solution of sodium hypochlorite to extract Pt, Rh and Behold, contained in the exhaust catalyst; after that the solution obtained by filtration, condense heating. Chloride hydrazine add in a condensed solution to redox potential amounted 600-450 mV; then interacts with 1-1,5 mol/l mortar phase extracting agent, which is a 2-ethyl hexyl ether, pre-treated with NaOH and last exchange of ions of Na for the dissolution of the extract of the CoE. Then, CE washed caustic from 0.5-1H and additionally subjected to reverse extraction with the use of a strong solution of hydrochloric acid. Dedicated thus CE return in the form of high-purity chloride solution cerium produced with high yield. This method is a complex, multistage, with the use of organic solvents are flammable and toxic substances. In addition, the composition of catalysts used in cars, not consistent with the composition of catalysts for dehydrogenation of in isoprene.

The closest to the claimed a method described in the patent GB 1148458 (A), C01F 17/00; C22B 59/00, publ. 1969-04-10], the essence of which consists in separation of particles cerium from other particles by the calcination of the material at a temperature 482-760°C, and the particles of cerium become soluble and other particles - in-soluble inorganic acids connection. Next to highlight the use of cerium leaching solution of hydrochloric or sulfuric acid at pH 0-1 and temperature 27-60°C, as a result of connection of cerium remains in the solid phase and other compounds into solution. However, this method is preferable for minerals , (chemical composition - content (%) : Behold 2 O 3 - 36,9-40,5; (La, TR) 2 O 3 - to 36.3; CeO 2 - 19,5-20,5; F - 2,2-8,5; H 2 O to 1.8.) or rare earth . The described method is not related to the extraction of cerium of catalysts and does not apply to materials with a complex composition is close to the catalysts.

Thus, the known ways of extraction of cerium refer to the source systems and catalysts at a different nature, therefore, not applicable for processing waste catalysts olefinic hydrocarbons, representing a system consisting of a mixture of oxides of metals of different nature. Earlier ways of processing of the fulfilled ferrioxide catalysts, specifically catalysts for dehydrogenation of olefinic hydrocarbons, with the extraction of valuable components, such as cerium, known and described were not.

The objective of this invention is the extraction of cerium as the most expensive component of the waste ferrioxide catalysts for dehydrogenation of olefinic hydrocarbons with obtaining cerium compounds of high purity.

Problem is solved, and the technical result is achieved, the claimed method extraction of cerium from waste ferrioxide catalysts for dehydrogenation of olefin hydrocarbons in which the extraction of cerium carried out after preliminary preparation of the catalyst for this at the preliminary processing stage of the catalyst:

- spend grinding spent catalyst;

- crushed catalyst annealed at temperatures 650-800°C for 3-6 hours;

after graduating from the calcination catalyst to cool to room temperature;

followed by extraction of cerium compounds: -conduct the dissolution of calcined catalyst in concentrated hydrochloric acid;

- solution is heated to boiling and withstand solution at a temperature of boiling (100-110°C) within 30-120 minutes;

- hold the shutter speed solution for the crystallization of cerium dioxide within 3-12 hours at a temperature of 0-20 C;

- after receiving the sediment it is separated from the mother liquor filtering, spending drain solution from the surface of the sediment on the filter with a pore size of the filter material not more than 2 mkm;

- the filter cake washed from compounds of iron and dried to a constant weight WWER cerium.

For dissolving take concentrated hydrochloric acid in the ratio of catalyst: acid equal 1:8-1:10.

Earlier ways of processing of the fulfilled ferrioxide catalysts, specifically catalysts for dehydrogenation of olefinic hydrocarbons, with the extraction of valuable components, such as cerium, known and described were not.

The method used the following products and reagents:

- waste catalysts for dehydrogenation of olefinic hydrocarbons ( in isoprene):

-- S6-34, Basf, Germany;

-- -08, Russia, TU 2173-134-5766801-2005;

-- BWW, Russia, TU 2173-134-5766801-2005;

- hydrochloric acid, class A GOST 3118-77;

- distilled water, GOST 6709-726709-72.

Oxide element

Range of content, % of mass.

Used exhaust catalyst pre-ground on the disintegrator. It is desirable that the crushing of the spent catalyst was conducted before the fractional composition of the particles is not more than 0.2 mm, which leads to acceleration of process of extraction - the smaller the particle size, the greater its surface, and the faster the reaction takes.

Further crushed catalyst subjected at a temperature of 650 to 800 C Calcination spent catalyst is necessary to increase the difference in the ability to dissolve in hydrochloric acid oxide compounds contained in catalyst. During annealing the reaction occurs the transformation of magnetite Fe 3 O 4-the basic component of catalysts in soluble in acids form in accordance with the equation of the reaction:

Magnetite Fe 3 O 4 little soluble in solutions of strong inorganic acids, unlike hematite Fe 2 O 3 .

In addition, during annealing spent catalyst oxidation also occurs CE 2 Of 3 the CeO 2 , solubility and CeO 2 in mineral acids significantly lower than solubility Ce 2 O 3 .

After calcinations conduct extraction of cerium compounds in the form of cerium dioxide, which in the heat Erlenmeyer flask with a reverse water, fridge pour concentrated hydrochloric acid in the ratio of catalyst: acid, kg/l, from 1:8 to 1:10 and fall asleep prepared catalyst, spend it dissolution in concentrated hydrochloric acid by mixing at a temperature of 30-110°C within 5-30 minutes. The major part of the catalyst switches to the solution, and ceria is in the form of fine suspended particles. Continue heating the solution to withstand a solution at a temperature of boiling (100-110°C) within 30-120 minutes, and crystallized sediment cerium dioxide. Upon expiration of the time the shutter speed solution for the formation of crystals cerium dioxide within 3-12 hours at a temperature of 0-20°C.

After receiving the sediment it is separated from the mother liquor filtration - merge solution from the surface of the sediment on the filter with a pore size of the filter material not more than 2 microns. The filter cake washed with distilled water volume equal to the volume of hydrochloric acid, preferably, with stirring sediment filter for better laundering of ferric chloride. After washing the precipitate it is still wet, ceria, which is sent for drying in a drying case at temperature of 105 C to constant mass obtaining cerium-containing finished product - cerium dioxide.

The proposed method allows us to extract from used catalysts for dehydrogenation of olefinic hydrocarbons, the most costly component of high yield and obtain a product of high purity.

Output (degree of extraction) the product is considered as the ratio of the content of cerium dioxide in the catalyst to actually extracted cerium dioxide. The best way out is achieved by variation and combination techniques and technological conditions of carrying out of experiments.

The purity of the obtained compounds is calculated from the results of their analysis x-ray fluorescence or atomic methods [GOST 23862.0-79. Rare-earth metals and their oxides. General requirements for methods of analysis. M: IPK Publishing standards. 2003; international standard ISO 12677:2003 Chemical analysis of refractories - method (XRF) using -alloy wheels» (ISO 12677:2003 Chemical analysis of refractory products by X-ray fluorescence (XRF) - Fused cast bead method); GOST 12364 - 84. Steel alloyed and high-alloyed. Methods for determination of cerium; GOST 23862.2-79. Rare-earth metals and their oxides. Direct spectral method for determination of impurities oxides of rare earth elements].

The invention is illustrated by examples of specific performance.

Table 1 shows examples of extraction of cerium of various waste catalysts for dehydrogenation of olefinic hydrocarbons and the results of extraction of cerium in various conditions.

Example 1

Chopped in the disintegrator about 120 g spent catalyst firm Basf, Germany, brand S6-34 containing 9,60% of the mass, cerium dioxide, up to the size of particles not exceeding 0.20 mm Crushed catalyst subjected in a muffle furnace at a temperature of 650C for 3 hours, then calcined catalyst cool to room temperature.

After the exposure time consistently merge a solution from the surface sediment and sediment filter with a pore size of the filter material not more than 2 microns. The filter cake washed with distilled water of 800 ml, with stirring sediment filter for better laundering of ferric chloride. After washing sludge is dried in a drying case at temperature of 105 C to constant weight in 3 hours. After cooling, the sediment, which is a ceria, it is weighed and analyze its composition. The mass of the resulting sludge cerium dioxide was 7,75,

The contents of elements in the catalyst in the sediment determined by x-ray fluorescence analysis. Was taken for analysis crushed and dried to a constant weight catalyst, and the composition of cerium dioxide determined in the sample after drying. According to the results, 100 g of the original sample catalyst contained 9.60 g SEO 2 , and in balance derived from cerium dioxide contained in the terms of oxides of 99.6% CEO 2% and 0.4% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product was 99.6%.

The degree of purity of the obtained cerium dioxide confirms also diffractogram CeO 2 obtained from spent catalyst shown in Fig.

All peaks in the x-ray relate to SEO 2 , [Crystallographic database WWW-MINCRYST. http://database.iem.ac.ru/mincryst/rus/; Crystallography Open Database http://sdpd.univ-lemans.fr/cod/]is almost identical to the data of the crystallographic database not only the values of the interplanar distances, but also values of the relative intensities of the peaks, which testifies to high degree of purity of the produced substances.

Output is considered as the ratio of the content of cerium dioxide in the catalyst to actually extracted cerium dioxide. Release calculation was carried out as follows.

100 g of the catalyst received 7,75 g cerium dioxide. Cerium dioxide content in the product is 99.6%, therefore the mass of the CeO 2 equals 7,75*0,996=7,72, the Output was: 7,72*100/9,60=80,4%.

Example 2

Spend as in example 1, with the following amendments.

Crushed catalyst firm Basf, Germany, brand S6-34, subjected in a muffle furnace at a temperature of 700oC C for 6 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 9.60 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.1% CeO 2 and 0.9% Fe 2 O3, that characterizes the purity of cerium dioxide. Thus, the purity of the product was 99,1%.

100 g of the catalyst received 7,90 g cerium dioxide. Cerium dioxide content in the product is 99.1%), therefore, the mass 0 2 equals 7,90*0,991=7,83 . amounted to: 7,83*100/9,60=81,5%.

Example 3

Spend as in example 1, with the following amendments.

Crushed catalyst firm Basf, Germany, brand S6-34, subjected in a muffle furnace at a temperature of 800 degrees C for 6 hours.

Withstand solution at a temperature of 20 to + / -3 C for the formation of crystals cerium dioxide within 12 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 9.60 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.0% CeO 2 and 1.0% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99,0%.

100 g of the catalyst received 7,93 g cerium dioxide. Cerium dioxide content in the product is 99.0%, therefore the mass of SEO 2 is equal to 7.93*0,990=7,85, the Output was: 7,85*100/9,60=81,8%.

Example 4

Spend as in example 1, with the following amendments.

Crushed catalyst firm Basf, Germany, brand S6-34, subjected in a muffle furnace at a temperature of 700oC C for 3 hours.

The temperature of the dissolution of the catalyst is 110 C.

Boiling solution in hydrochloric acid is 30 minutes.

The aging time of the solution at a temperature of 0 to + / -3 C for the formation of crystals cerium dioxide is 3 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 9.60 g SEO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.1% CEO 2 and 0.9% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product was 99,1%.

100 g of the catalyst received 7,87 g cerium dioxide. Cerium dioxide content in the product is 99.1%, therefore the mass of the CeO 2 equals 7,87*0,990=7,80, the Output was: 7,80*100/9,60=81,2%.

Example 5

Spend as in example 1, with the following amendments.

Crushed catalyst firm Basf, Germany, brand S6-34, subjected in a muffle furnace at a temperature of 700oC C for 6 hours.

The ratio of hydrochloric acid to the mass of the catalyst is 10:1 ml/year

Boiling solution in hydrochloric acid is 30 minutes. The aging time of the solution at a temperature of 20 to + / -3 C for the formation of crystals cerium dioxide is 3 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 9.60 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.5% CeO 2% and 0.5% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99.5%.

Spend as in example 1, with the following amendments. As the spent catalyst for dehydrogenation of in isoprene use -08, the composition of which is the following:

Oxide element

Content, % of mass.

Crushed catalyst brand -08 (Russia)subjected in a muffle furnace at a temperature of 700oC C for 6 hours.

The temperature of the dissolution of the catalyst is 110 C.

Boiling solution in hydrochloric acid is 30 minutes.

According to the results of the analyses in 100 g of the original sample catalyst contained 11,40 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides 99,3% CeO 2 and 0.7% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99.3%.

100 g of the catalyst received 9,29 g cerium dioxide. Cerium dioxide content in the product is 99,3%, therefore the mass of SEO 2 equals 9,29*0,993=9,22, the Output was: 9,22*100/11,40=80,9%.

Example 7

Spend as in example 1, with the following amendments.

Crushed catalyst brand -08 (Russia)subjected in a muffle furnace at a temperature of 700oC C for 6 hours.

The ratio of hydrochloric acid to the mass of the catalyst is 10:1 ml/year

According to the results of the analyses in 100 g of the original sample catalyst contained 11,40 g SEO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.0% CEO 2 and 1.0% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99,0%.

100 g of the catalyst received 9,34 g cerium dioxide. Cerium dioxide content in the product is 99.0%, therefore the mass of SEO 2 equals 9,34*0,990=9,25, the Output was: 9,25*100/11,40=81,1%.

Example 8

Spend as in example 1, with the following amendments.

Crushed catalyst brand -08 (Russia)subjected in a muffle furnace at a temperature of 800 degrees C for 3 hours.

The ratio of hydrochloric acid to the mass of the catalyst is 10:1 ml/year

Boiling solution in hydrochloric acid is 30 minutes.

According to the results of the analyses in 100 g of the original sample catalyst contained 11,40 g SEO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.4% CEO 2 and 0.6% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99.4 per cent.

100 g of the catalyst received 9,37 g cerium dioxide. Cerium dioxide content in the product was 99.4%, therefore the mass of the CeO 2 equals 9,37*0,994=to 9.32, the Output was: to 9.32*100/11,40=81,7%.

Example 9

Spend as in example 1, with the following amendments. Use exhaust catalyst the following composition:

Oxide element

content, % mass

Crushed catalyst brand (Russia)subjected in a muffle furnace at a temperature of 800 degrees C for 3 hours.

The aging time of the solution at a temperature of 0 to + / -3 C for the formation of crystals cerium dioxide is 6 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 7,10 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides 99,2% CeO 2 and 0.8% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99.2%.

100 g of the catalyst received 5,78 g cerium dioxide. Cerium dioxide content in the product or 99.2%, therefore the mass of the CeO 2 equals 5,78*0,992=5,74, the Output was: 5,74*100/7,10=80,8%.

Example 10

Spend as in example 1, with the following amendments.

Crushed catalyst brand (Russia)subjected in a muffle furnace at a temperature of 700oC C for 6 hours.

The ratio of hydrochloric acid to the mass of the catalyst is 10:1 ml/year

The aging time of the solution at a temperature of 20 to + / -3 C for the formation of crystals cerium dioxide is 3 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 7,10 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides of 99.6% CeO 2% and 0.4% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product was 99.6%.

100 g of the catalyst received 5,80 g cerium dioxide. Cerium dioxide content in the product is 99.6%, therefore the mass of the CeO 2 equals 5,80*0,996=5,77, the Output was: 5,77*100/7,10=81,3%.

Example 11

Spend as in example 1, with the following amendments.

Crushed catalyst brand (Russia)subjected in a muffle furnace at a temperature of 800 degrees C for 6 hours.

The aging time of the solution at a temperature of 20 to + / -3 C for the formation of crystals cerium dioxide is 12 hours.

According to the results of the analyses in 100 g of the original sample catalyst contained 7,10 g CeO 2 , and in the dried sediment derived from cerium dioxide contained in the terms of oxides 99,3% CeO 2 and 0.7% Fe 2 O 3 that characterizes the purity of cerium dioxide. Thus, the purity of the product amounted to 99.3%.

100 g of the catalyst received 5,83 g cerium dioxide. Cerium dioxide content in the product is 99,3%, therefore the mass of the CeO 2 equals 5,83*0,993=5,79, the Output was: 5,79*100/7,10=81,5%.

Examples of extraction of cerium.

View catalyst

Calcination temperature °C

Time calcination, h

The ratio of the volume of acid to the mass of catalyst g:ml

Temperature of dissolution, C

Boiling, min

Crystallization temperature, C

Time of crystallization, hour

Cerium dioxide content in the catalyst, g

Weight cerium dioxide in the dried residue, g

Output, %

Cleanliness %

-08

-08

-08

1. Method of extraction of cerium from waste catalysts for dehydrogenation of olefinic hydrocarbons, which consists in the fact that the extraction of cerium carried out after preliminary preparation of the catalyst, thus conduct grinding spent catalyst, chopped catalyst subjected at a temperature of 650-800°for 3-6 h after calcination catalyst to cool to room temperature and conduct extraction of cerium compounds dissolution of calcined catalyst in concentrated hydrochloric acid, solution obtained with suspended particles cerium dioxide is heated to boiling, maintained at a temperature of boiling 100-110°for 30-120 min and within 3-12 hours at a temperature of 0-20°C with obtaining of sludge, which separated from the mother solution by filtration through plum solution from the surface of the sediment on the filter with a pore size of the filter material not more than 2 microns, the filter cake washed from compounds of iron and dried to a constant weight cerium dioxide.

2. The method according to claim 1, wherein the dissolution take concentrated hydrochloric acid in the ratio to the catalyst equal to 8:1 to 10:1.