WO2023229494A1

WO2023229494A1 - Method for extracting vanadium from petroleum coke combustion ash

Info

Publication number: WO2023229494A1
Application number: PCT/RU2023/050053
Authority: WO
Inventors: Инсаф Шарифуллович САЙФУЛЛИН; Николай Захарович ЛЯХОВ; Галина Алексеевна ЛУКОМСКАЯ; Владимир Леонидович СКОБЕЛЕВ; Камиль Закирьянович ШАКИРОВ; Наиль Ульфатович Маганов; Рудольф Дитрихович РЕМПЕЛЬ; Тагир Самигуллович АЙНУЛЛОВ; Алексей Владимирович Зурбашев
Original assignee: Публичное акционерное общество "Татнефть" имени В.Д. Шашина
Priority date: 2022-05-26
Filing date: 2023-03-17
Publication date: 2023-11-30

Abstract

The invention relates to the field of chemical technology and non-ferrous metallurgy and can be used for extracting vanadium from petroleum coke combustion ash. Petroleum coke combustion ash is leached, and vanadium is then extracted from the pregnant solution. Leaching is carried out using a solution of sulphuric acid with a concentration of from 20 to 50 g/l at a temperature of from 20 to 50°С for 2 hours with sodium sulphite or calcium sulphite or ammonium sulphite being added during the leaching process in an amount whereby sulphite ions are equivalent to 80-140% of the vanadium content of the ash. Vanadium is extracted from the pregnant solution by precipitating the hydroxide of vanadium (+4) during neutralization of the obtained solution with soda ash or caustic soda to pH 6-8. The method makes it possible to achieve a high level of extraction of vanadium into solution from both vanadium-poor and vanadium-rich ash, as well as to increase the productivity of the method and to reduce energy and material costs.

Description

Method for extracting vanadium from petroleum coke combustion ash

The present invention relates to the field of chemical technology and non-ferrous metallurgy and can be used to extract vanadium from petroleum coke combustion ash.

In known methods, vanadium is leached either directly from petcoke after its preliminary preparation, or from ash obtained by burning petcoke.

There is a known method for extracting vanadium from petroleum coke (RU patent No. 2647725, MIK S22V 34/22, S22V 3/06, S22V 7/00, publ. 03/19/2018, Bulletin No. 8), including its grinding to a particle size of 0.100 mm and leaching, where leaching is carried out in a mixture of concentrated sulfuric and nitric acids in a ratio of 1:1 at a temperature of 95 to 105°C with a ratio of petroleum coke to a mixture of acids of 1:3 to 3:1 for 1 to 2 hours.

The disadvantages of this method are the high energy costs of maintaining a temperature from 95 to 105°C with a ratio of petroleum coke and a mixture of acids from 1:3 to 3:1 for 1 to 2 hours and high material costs for using large quantities of concentrated acids. Another disadvantage is that the use of petroleum coke treated with concentrated acids as a fuel during subsequent combustion is a big problem.

There is also a known method for extracting vanadium and nickel from coke for demetallization of petroleum feedstock (RU patent No. 2685290, MPK S22V 34/22, S22V 7/00, SOYU 31/00, SOYU 53/10, published 04/17/2019, Bulletin No. 11 ), including grinding of raw materials in the presence of an alkali metal salt, oxidative roasting, leaching by heating with water and sequential isolation of vanadium and nickel compounds, while grinding is carried out in the presence of 0.1 -0.3 May. % manganese dioxide to particles whose size does not exceed 0.05 mm, 8-10 wt. are used as an alkali metal salt. % sodium chloride, 0.5-1.0 wt. % carbonate sodium, before oxidative roasting, granulation is carried out in the presence of an ammonium nitrate solution, oxidative roasting is carried out in four stages in compliance with the temperature regime:

1) heating and drying from 20 to 150-200°C,

2) preliminary calcination from 150-200 to 650°C,

3) calcination at a constant temperature of 850°C,

4) cooling from 850 to 120°C,

Leaching is carried out sequentially with water at a ratio of S:L = 1: 2.0-2.5 and a solution of sulfuric acid at a ratio of S:L = 1: 1-2.5 in the presence of an oxidizing agent H2O2, the leaching solutions with water and acid are combined and separation is carried out vanadium and nickel compounds.

The disadvantages of this method are the high energy costs of maintaining the temperature, especially for calcination - 850 °C and the high material costs of using large quantities of hydrogen peroxide (H2O2), as well as the need to introduce a complex mixture of sodium chloride, manganese dioxide and nitrate into the charge before firing .

The closest to the proposed method in terms of the conditions for preparing ash is the method for extracting metals from refining residues (patent RU No. 2578891, MPK S22V 26/20, S22V 7/00, S22V 3/04, publ. 03.27.2016, bulletin No. 9). The method involves burning petroleum coke at temperatures up to 900 °C to use the resulting heat in the energy sector. From the resulting ash, oxidative leaching of vanadium (+5) and molybdenum (+6) is carried out with a solution of sodium hydroxide with the addition of hydrogen peroxide and sulfuric acid leaching of nickel from the resulting cake. From an alkaline productive solution, selective precipitation of ammonium vanadate and ammonium polymolybdate is carried out by adjusting the pH with acid and adding ammonium sulfate. Nickel is precipitated as hydroxide as a result of neutralization of the sulfuric acid solution with magnesium oxide.

The disadvantages of this method include high energy costs for maintaining temperature, high consumption of reagents and complex composition of waste solutions, the need for additional equipment and premises for its placement. In addition, the method can be relatively effective only if metal-rich ash is processed and alkaline solutions rich in vanadium and molybdenum are obtained, since the precipitation of ammonium vanadate and ammonium polymolybdate with an acceptable degree of extraction is technically possible only from rich solutions.

Technical objectives are to create a method for extracting vanadium from ash, ensuring a high degree of extraction of vanadium into solution from both poor and vanadium-rich ash, increasing the productivity of the method by eliminating preliminary oxidative roasting and other additional operations of vanadium oxidation, reducing energy and material costs due to the extraction of vanadium using the optimal technological regime without additional reagents and equipment.

Technical problems are solved by a method for extracting vanadium from petroleum coke combustion ash, including leaching of petroleum coke combustion ash and subsequent extraction of vanadium from the productive solution.

What is new is that leaching is carried out with a solution of sulfuric acid with a concentration of 20 to 50 g/l at a temperature of 20 to 50 ° C for 2 hours; during the leaching process, sodium sulfite or calcium sulfite, or ammonium sulfite is added in an amount of 80-140 % of sulfite ion from the vanadium content in the ash, and the extraction of vanadium from the productive solution is carried out by precipitation of vanadium hydroxide (+4) in the process of neutralizing the resulting solution with soda ash or caustic soda to pH 6-8.

Also new is that sodium salt of sulfurous acid with an active sulfite ion content of 57-63% is used as sodium sulfite. Also new is that calcium salt of sulfurous acid with an active sulfite ion content of 40-66% is used as calcium sulfite.

Also new is that a solution of ammonium sulfite-bisulfite with an active sulfite ion content of 12-40% is used as ammonium sulfite.

To implement the method use:

Sodium sulfite is an inorganic compound, sodium salt of sulfurous acid with the chemical formula NagS03, according to GOST 5644-75, used as a vanadium reducing agent (+5), with an active sulfite ion content of 57-63%.

Calcium sulfite is an inorganic compound, a calcium salt of sulfurous acid with the chemical formula Ca803, a precipitate with an active sulfite ion content of 40-66%.

Ammonium sulfite - as ammonium sulfite (due to its instability in dry form), an industrial solution of ammonium sulfite-bisulfite is used, containing ammonium sulfite (NH4)2SO3 and ammonium bisulfite NH4HSO3 in various proportions and qualified by the content of sulfite ion as a solution with pH 4, 6-6, 8, with a content of active sulfite ion of 12-40%.

Commercial sulfuric acid H2SO4 in accordance with GOST 2184-2013 for preparing a solution for vanadium leaching.

Soda ash NagCO3 according to GOST 5100-85 in dry form or in the form of a 20% solution, or caustic soda (caustic soda) according to GOST R55064-2012.

The proposed method for extracting vanadium from petroleum coke combustion ash involves leaching the petroleum coke combustion ash and subsequent extraction of vanadium from the productive solution.

Leaching is carried out with a solution of sulfuric acid with a concentration of 20 -50 g/l (pH 0.7-0.8) at a temperature of 20 to 50°C for 2 hours with by adding sulfite salts to the pulp during the leaching process: sodium sulfite or calcium sulfite, or ammonium sulfite, as a reducing agent of vanadium (+5) to vanadium (+4).

The selected leaching condition - the sulfuric acid concentration range of 20-50 g/l - ensures that vanadium is transferred into solution in the form of a stable and soluble vanadyl ion VO 2+, in which vanadium has an oxidation state of +4. A sulfuric acid concentration of more than 50 g/l is excessive, and at a concentration of less than 20 g/l, polymeric forms of vanadium (+5) may appear in the solution, which can negatively affect the completeness of the subsequent separation of vanadium from the solution.

The leaching temperature regime - 20-50 °C, on the one hand, provides the necessary rate of reduction of vanadium with sulfite ion, on the other hand, ensures sufficient solubility of the sulfite ion, preventing the distillation of sulfur dioxide. The proposed temperature range makes it possible to create in the solution the maximum concentration of the reducing agent - sulfite ion, with minimal losses to side processes that intensify with increasing temperature.

For effective absorption of the reducing agent - sodium sulfite, or calcium sulfite, or ammonium sulfite, it is recommended to introduce it into the process in an amount of 80-140% of the sulfite ion of the vanadium content in the ash. This amount is necessary and sufficient to achieve the required extraction of vanadium into the solution. At a lower flow rate, the required completeness of vanadium recovery (+5) is not achieved and the extraction of vanadium into the solution is reduced. With a higher consumption of sulfite ion, part of the reagent is not absorbed by the ash. The resulting excess decomposes in an acidic environment with the formation of sulfur dioxide, which is distilled into the gas phase and pollutes the environment.

The duration of leaching - 2 hours is sufficient, during this time sodium sulfite, or calcium sulfite, or ammonium sulfite interacts with vanadium (+5) and other components of the ash, with This ensures complete assimilation of the sulfite ion and the elimination of the leakage of unassimilated sulfur dioxide.

Vanadium (+4) is extracted from the resulting productive solution by precipitating it in the form of poorly soluble vanadium hydroxide (+4) V(OH)4. The maximum completeness of vanadium precipitation is achieved by neutralizing the solution with soda ash or caustic soda to pH 6-8.

If molybdenum and nickel are present in the initial ash, these metals are also transferred into solution during the leaching of vanadium. From the productive solution, molybdenum is extracted selectively by sorption on a weakly basic anion exchanger using a known technology before the precipitation of vanadium, and nickel is precipitated in the form of a basic carbonate after the precipitation of vanadium, by increasing the pH to 9-10 with soda, also using a known method.

In comparison with existing methods for extracting vanadium from the ash of burning fuel oil or coke, the proposed method for extracting vanadium from the ash of burning petroleum coke eliminates the operations of oxidative roasting of the ash, leaching of vanadium with a solution of soda or alkali in the presence of an oxidizing agent - hydrogen peroxide, and a complex scheme for separating vanadium from alkali solutions or soda used for leaching.

In the process of burning petroleum coke, depending on the completeness of combustion, ash can be obtained that differs in the content of vanadium and other components: poor (ash in which the content of a useful component (metal) is not high, therefore, when processing such ash using known methods, additional concentration operations are required vanadium) and relatively rich ash (ash that does not require additional concentration). Typical compositions are shown in the table. The most representative composition is sample No. 2, which refers to the poor. When ash is leached in the presence of sodium sulfite or calcium sulfite, or ammonium sulfite, a high degree of vanadium extraction into solution is achieved from both vanadium-poor and vanadium-rich ash. During the subsequent precipitation of vanadium under the selected conditions, a high degree of vanadium precipitation is achieved both from poor solutions and from rich solutions (in contrast to the prototype, according to which it is difficult to precipitate ammonium vanadate from poor solutions without concentration). The resulting enriched precipitates of vanadium (+4) hydroxide can be processed into vanadium pentoxide by known methods.

We will consider the implementation of the method using examples of specific implementation on samples with different contents of vanadium and other components, the composition of which is given in the table.

Table. Content of main components in ash samples

Examples of practical application.

Example 1. A weighed 100 g sample of crushed petroleum coke combustion ash No. 1 is mixed in a reactor with 500 ml of sulfuric acid solution with a concentration of 50 g/l at a temperature of 30°C. During the leaching process, sodium sulfite is added to the pulp with an active sulfite ion content of 58.4%. The total consumption of sodium sulfite is 1.46 g (which corresponds to 140% of the sulfite ion content of vanadium in a sample of ash, the amount of vanadium V in the first sample is 0.61%).

So, if a 100 g sample contains 0.61 g of vanadium, then the amount of sulfite ion: 0.61x140/100 = 0.854 g. If the content of sulfite ion in sodium sulfite is 58.4%, the amount of sodium sulfite is: 0.854 xO/58, 4= 1.46 g. The duration of the process is 2 hours. Soda ash is added to the solution filtered after leaching with a vanadium content of 1.1 g/l until the solution reaches pH 8. The resulting precipitate of vanadium hydroxides (+4) is filtered and dried. The residual vanadium content in the filtered solution was 0.03 g/l. Recovery at the precipitation stage is 97.3%. The yield of vanadium sediment is 2.2 g, the vanadium content in it is 27.3%. The residual vanadium content in the leaching cake after washing with a sulfuric acid solution was 0.07%, which corresponds to the extraction of vanadium into the solution with leaching of 88.5%. The total recovery of vanadium is 86.1%.

Example 2. A 100 g sample weighing 100 g of crushed ash from sample No. 2 is mixed in a reactor with 500 ml of sulfuric acid solution with a concentration of 20 g/l at a temperature of 20°C. During the leaching process, sodium sulfite with a sulfite ion content of 58.4% is added to the pulp. The total consumption of sodium sulfite was 10.1 g (which corresponds to 140% of the sulfite ion of the vanadium content, which in the second sample was 4.22%). The duration of the process is 2 hours. Caustic soda is added to the filtered solution after leaching containing 8.23 g/l of vanadium with stirring until the solution reaches a pH of 7.6. The resulting precipitate of vanadium hydroxides (+4) is filtered off and dried. The residual vanadium content in the filtered solution was 0.03 g/l. Recovery at the precipitation stage is 99.6%. The yield of vanadium sediment was 11.76 g, its vanadium content was 34.3%. The residual vanadium content in the cake after ash leaching was 0.056%. The total recovery of vanadium into the product was 98.0%.

Example 3. A 100 g sample of crushed ash from sample No. 3 is mixed with 500 ml of sulfuric acid solution with a concentration of 45 g/l at a temperature of 50 °C, while sodium sulfite with a sulfite ion content of 58.4% is added to the pulp. The total consumption of sodium sulfite is 29 g (which corresponds to 140% of the sulfite ion of the amount of vanadium in the ash sample, the vanadium V content in the third sample is 12.1%).

The duration of the process is 2 hours. Soda ash is added to the filtered solution after leaching containing 23.8 g/l of vanadium with stirring until the solution reaches pH 6. The resulting precipitate is filtered off and dried. The sediment yield was 26.7 g, the vanadium content in it was 50.19%. The residual vanadium content in the solution after precipitation is 0.064 g/l, extraction during precipitation is 99.7%. The residual vanadium content in the cake after leaching is 0.21%. Extraction into solution - 98.3%. The total recovery of vanadium into the product was 98.0%.

Example 4. A 100 g sample of crushed ash from sample No. 3 is mixed with 500 ml of sulfuric acid solution with a concentration of 45 g/l at a temperature of 50 °C, while sodium sulfite with a sulfite ion content of 58.4% is added to the pulp. The total consumption of sodium sulfite is 18.1 g (which corresponds to 87.6% of the vanadium content in the ash sample, the vanadium V content in the third sample is 12.1%). The duration of the process is 2 hours. Caustic soda is added to the filtered solution after leaching containing 22.9 g/l of vanadium with stirring until the solution reaches pH 6. The resulting precipitate is filtered off and dried. The sediment yield was 23.0 g, the vanadium content in it was 48.7%. The residual vanadium content in the solution after precipitation is 0.072 g/l, extraction during precipitation is 99.7%. The residual vanadium content in the cake after leaching is 0.64%. Extraction into solution - 94.7% The total extraction of vanadium into the product was 94.4%.

Example 5. A 100 g sample weighing 100 g of crushed ash from sample No. 2 is mixed in a reactor with 500 ml of sulfuric acid solution with a concentration of 35 g/l at a temperature of 20°C. During the leaching process, a solution of ammonium sulfite with a sulfite ion concentration of 18% is added to the pulp. The total consumption of sulfite ion was 3.4 g (80% of the amount of vanadium in the sample), which corresponds to the amount of ammonium sulfite-bisulfite solution - 18.7 g. The duration of the process is 2 hours. Caustic soda is added to the solution filtered after leaching with a vanadium content of 8.04 g/l with stirring until the solution reaches a pH of 7.6. The resulting precipitate of vanadium hydroxides (+4) is filtered off and dried. The residual vanadium content in the filtered solution was 0.03 g/l. Recovery during sedimentation is 99.6%. The yield of vanadium sediment was 11.9 g, its vanadium content was 33.9%. The residual vanadium content in the cake after ash leaching was 0.2%. The total recovery of vanadium into the product was 94.9%.

Example 6. A 100 g sample of crushed ash from sample No. 2 is mixed in a reactor with 500 ml of sulfuric acid solution with a concentration of 50 g/l at a temperature of 20°C. During the leaching process, a solution of ammonium sulfite with a sulfite ion concentration of 18% is added to the pulp. The total consumption of sulfite ion was 5.9 g (140% of the vanadium content in the ash sample, which is 4.22% in the second sample), which is contained in 32.8 g of sulfite-bisulfite solution. The duration of the process is 2 hours. Caustic soda is added to the filtered solution after leaching containing 8.23 g/l of vanadium with stirring until the solution reaches a pH of 7.6. The resulting precipitate of vanadium hydroxides (+4) is filtered off and dried. The residual vanadium content in the filtered solution was 0.03 g/l. Recovery during precipitation - 99.6%. The yield of vanadium sediment was 12.3 g, its vanadium content was 33.1%. The residual vanadium content in the cake after ash leaching was 0.12%. The total recovery of vanadium into the product was 97.2%.

Example 7. A 100 g sample weighing 100 g of crushed ash from sample No. 2 is mixed in a reactor with 500 ml of sulfuric acid solution with a concentration of 50 g/l at a temperature of 40°C. During the leaching process, calcium sulfite with a sulfite ion content of 52% is added to the pulp. The total consumption of sulfite ion was 5.06 g (120% of the vanadium content in the ash sample, which was 4.22% in the second sample), which was contained in 9.74 g technical calcium sulfite Process duration - 2 hours. Caustic soda is added to the solution filtered after leaching with a vanadium content of 8.15 g/l with stirring until the solution reaches a pH of 6.6. The resulting precipitate of vanadium hydroxides (+4) is filtered off and dried. The residual vanadium content in the filtered solution was 0.03 g/l. Recovery during precipitation - 99.6%. The yield of vanadium sediment was 12.6 g, its vanadium content was 32.0%. The residual vanadium content in the cake after ash leaching was 0.145%. The total recovery of vanadium from ash to sediment was 96.2%.

The above examples show that when leaching ash in the presence of sodium sulfite or calcium sulfite, or ammonium sulfite, a high degree of extraction of vanadium into solution is achieved from both vanadium-poor and vanadium-rich ash. During the subsequent precipitation of vanadium under the selected conditions, a high degree of vanadium precipitation is achieved both from poor solutions and from rich solutions. The resulting enriched precipitates of vanadium (+4) hydroxide can be processed into vanadium pentoxide by known methods.

The proposed method for extracting vanadium from ash provides a high degree of extraction of vanadium into solution, the degree of precipitation (extraction) of vanadium is 97-99.7%, the total extraction of vanadium from the ash of burning petroleum coke into sediment is 86-98%, the productivity of the method increases (the total time spent on implementing the method) due to the exclusion of preliminary oxidative roasting and other additional operations of vanadium oxidation. Also, the proposed method for extracting vanadium from petroleum coke combustion ash allows for significant savings in material resources by eliminating the high consumption of expensive reagents (caustic soda, ammonium salts and hydrogen peroxide) and additional equipment, the possibility of neutralizing the resulting solution with cheap soda, as well as the possibility of extracting vanadium from both rich and lean ash, without reducing the efficiency of vanadium extraction. In addition, the problem of recycling waste solutions of a less complex composition is significantly simplified in comparison with the prototype.

Claims

Claim

1. A method for extracting vanadium from petroleum coke combustion ash, including leaching of petroleum coke combustion ash and subsequent extraction of vanadium from the productive solution, characterized in that leaching is carried out with a sulfuric acid solution with a concentration of 20 to 50 g/l at a temperature of 20 to 50° C for 2 hours, during the leaching process, sodium sulfite or calcium sulfite, or ammonium sulfite is added in an amount of 80-140% of the sulfite ion of the vanadium content in the ash, and vanadium is extracted from the productive solution by precipitation of vanadium hydroxide (+4) in the process of neutralizing the resulting solution with soda ash or caustic soda to pH 6-8.

2. The method for extracting vanadium from petroleum coke combustion ash according to claim 1, characterized in that sodium salt of sulfurous acid with an active sulfite ion content of 57-63% is used as sodium sulfite.

3. The method for extracting vanadium from petroleum coke combustion ash according to claim 1, characterized in that the calcium salt of sulfurous acid with an active sulfite ion content of 40-66% is used as calcium sulfite.

4. A method for extracting vanadium from petroleum coke combustion ash according to claim 1, characterized in that a solution of ammonium sulfite-bisulfite with an active sulfite ion content of 12-40 is used as ammonium sulfite