RU2847995C1 - Method for controlling the acid leaching process of calcined vanadium-containing clinker - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: present invention discloses a method for controlling the acid leaching process of calcined burnt vanadium-containing clinker. The method includes mixing the calcined burnt clinker with a first leaching agent to obtain a clinker suspension; mixing concentrated sulphuric acid with a second leaching agent to obtain a first solution; adding the first solution to the clinker suspension at a uniform rate to obtain a third solution; controlling the pH of the third solution at a level of 2.5-3.5; carrying out a leaching reaction, followed by solid-liquid separation to obtain a vanadium-containing leaching solution and vanadium extraction tailings.

EFFECT: reduction of vanadium losses during acid leaching, reduction of leaching time, prevention of local high temperatures, acidity and high impurity content caused by the direct addition of concentrated sulphuric acid.

9 cl, 1 dwg, 8 ex

Description

Field of technology

The present invention relates to the technical field of vanadium hydrometallurgy and, in particular, to a method for controlling the process of acid leaching of calcined burnt clinker.

State of the art

Vanadium, an important microalloying element, is widely used in metallurgy, the chemical industry, aerospace, and other fields. It significantly improves the strength, toughness, ductility, and other properties of steel, and also provides important support for quality assurance in key national projects. Vanadium and titanium magnetite are processed in blast furnaces or electric furnaces at high temperatures to produce vanadium-containing ferrowater. Vanadium slag is obtained by selective oxidation of ferrowater, which is used as a raw material for vanadium extraction. In the production of vanadium oxide, typical vanadium extraction processes include calcination roasting and acid leaching of vanadium-containing materials.

After calcination and roasting of vanadium slag, vanadium exists in the form of pentavalent vanadium, which can be dissolved in the solution by adding sulfuric acid to control the leaching pH of 2.8-3.5. More than 80% of the vanadium leaching reaction occurs within 15 minutes of the start of the leaching process, requiring a large amount of sulfuric acid consumed during this time. In actual production, localized excess acidity is usually caused by the rapid addition of sulfuric acid, uneven addition, and so on. Depending on the vanadium form, at a low pH of the leaching solution and a high concentration of pentavalent vanadium, the solution system becomes unstable, vanadium easily hydrolyzes and precipitates, leading to vanadium losses. Therefore, the TV content in vanadium mining tailings obtained from industrial production fluctuates greatly and ranges from 1.0% to 1.7%.

Thus, the problem of excessive local acidity, which easily leads to vanadium loss, during acid leaching of calcined burnt clinker has become a technical challenge that needs to be addressed by specialists in this field.

Based on this, the prior art still needs improvement.

Brief description of the invention

In order to solve the above technical problem, in some embodiments of the present invention, a method is provided for controlling the process of acid leaching of calcined calcined clinker to solve the technical problem caused by excessive local acidity in the process of acid leaching of calcined calcined clinker of the prior art.

In order to solve the above technical problem, in some embodiments of the present invention, a method for controlling the process of acid leaching of calcined burnt clinker is disclosed, in which the leaching agent is divided into two parts, where one part is used to prepare a clinker suspension by mixing with calcined burnt clinker, and the other part is used to dilute concentrated sulfuric acid.

Additionally, it includes:

Stage 1: mixing the calcined burnt clinker with the first leaching agent to obtain a clinker slurry;

Step 2: Mixing concentrated sulfuric acid with the second leaching agent to produce the first solution;

Stage 3: adding the first solution to the clinker slurry at a uniform rate to obtain the third solution;

Step 4: controlling the pH of the said third solution at 2.5~3.5, carrying out the leaching reaction, and then solid-liquid separation to obtain a vanadium-containing leaching solution and a vanadium extraction tail product.

Additionally, in the second stage, the amount of the said concentrated sulfuric acid is 0.6-0.8 times greater than the total amount of concentrated sulfuric acid consumed in the process of leaching calcined burnt clinker.

Additionally, in the first stage, the mass ratio of said calcined burnt clinker and said first leaching agent is 1:1~2.

Additionally, in the first stage, the first leaching agent is water, reused wastewater treatment water, or a vanadium-containing solution.

Additionally, in the second stage, the second leaching agent is water or recycled wastewater.

Additionally, in the third stage, said first solution is added to said clinker suspension at a uniform rate for 15 minutes or more.

The time for adding the first solution to the clinker suspension at a uniform rate is 15-25 minutes.

Additionally, said third solution has a liquid to solid mass ratio of (2~10):1;

Preferably, the mass ratio of liquid to solid in said third solution is (2~4):1.

In addition, said vanadium-containing solution includes a vanadium tailings wash solution.

By using the above technical solution, the present invention has at least the following positive effects:

The present invention provides a method for controlling the acid leaching process of calcined burnt clinker with low cost and ease of operation, in which the leaching agent is divided into two parts for use, where one part is used for grinding clinker, the other part is used for diluting concentrated sulfuric acid used for leaching, and then adding a leaching agent containing sulfuric acid to a clinker suspension to improve the liquid-to-solid ratio in the suspension and at the same time achieving rapid leaching of vanadium, and preventing local high acidity, high temperature and high impurity content caused by the direct addition of concentrated sulfuric acid.

Description of graphic materials

In order to more clearly illustrate the technical solutions in the embodiments or prior art of the present invention, the accompanying drawings will be briefly presented below, which will be used in describing the embodiments or prior art, and it is obvious that the accompanying drawings in the following description represent only some embodiments of the present invention, and that for a person skilled in the art, other accompanying drawings can be obtained in accordance with these drawings without creative work.

Fig. 1 shows a block diagram of a method for controlling the process of acid leaching of calcined fired clinker disclosed in some embodiments of the present invention.

Detailed description

The following detailed description of embodiments of the present invention is described in more detail in connection with the accompanying drawings and embodiments. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present invention, but should not be used to limit the scope of the present invention, which can be implemented in many different forms and is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

These embodiments are provided to make the invention comprehensive and complete and to adequately convey the scope of the invention to those skilled in the art. It should be noted that the relative arrangement of parts and steps, components, materials, numerical expressions, and values given in these embodiments of the invention should be considered exemplary and not limiting, unless otherwise specifically stated.

It should be noted that in the description of the present invention, unless otherwise specified, "multiple" means greater than or equal to two; the terms "upper," "lower," "left," "right," "inside," "outside," and the like indicate orientation or positional relationships only for the purpose of facilitating the description of the invention and simplifying the description. The present invention and the simplification of the description are not intended to indicate or imply that the mentioned device or element must have a certain orientation, be constructed, and operate in a certain orientation, and therefore should not be considered as a limitation of the present invention. If the absolute position of the described object changes, the relative positional relationship can be changed accordingly.

Furthermore, the words "first," "second," and the like, as used in the present invention, do not indicate any order, quantity, or importance, but are used only to distinguish various parts. "Perpendicular" is not strictly perpendicular, but is within the margin of error. "Parallel" is not strictly parallel, but is within the margin of error. The words "including" or "containing" and other similar words mean that the elements preceding the word encompass the elements listed after the word and do not exclude the possibility of encompassing other elements.

It should also be noted that in the description of the present invention, unless otherwise expressly provided and limited, the terms "installed," "connected," and "attached" should be understood in a broad sense, for example, it can be a fixed connection or a connectable connection. For example, it can be fixed, removable, or integrated; it can be directly or indirectly connected via an intermediate carrier. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood in each individual case. When a specific device is described as located between a first device and a second device, there may or may not be an intermediate device between this specific device and the first device or the second device.

All terms used in this document have the same meaning as understood by a person skilled in the art to which this invention pertains, unless otherwise defined. It should also be understood that terms defined, for example, in a general-purpose dictionary, should be interpreted as having a meaning corresponding to their meaning in the context of the relevant technology and should not be interpreted with idealized or highly formalized meanings unless expressly defined herein.

Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, the techniques, methods, and devices should be considered as part of the specification.

As shown in Fig. 1, in some embodiments of the present invention, a method for controlling the acid leaching process of calcined calcined clinker is disclosed, in which the leaching agent is divided into two parts, where one part is used to prepare clinker slurry by mixing with calcined calcined clinker, and the other part is used to dilute concentrated sulfuric acid. In particular, the control method may consist of the following steps:

Step 1. Mixing the calcined burned clinker with the first leaching agent to obtain a clinker slurry; wherein the weight ratio of the calcined burned clinker and the total first leaching agent is preferably 1:1~2. Said first leaching agent may be selected from water, reused wastewater treatment water, or a vanadium-containing solution, wherein the vanadium-containing solution may include, but is not limited to, a vanadium tailings wash solution or a vanadium-containing leaching solvent, i.e., a wash filtrate obtained at the end of the acid leaching after filtration and washing. The leaching solvent in the first acid leaching may be process water, which may be filtered and washed to produce vanadium-containing solvent for reuse in the next leaching, and the wash filtrate may be used as vanadium-containing leaching solvent.

Step 2. Mixing concentrated sulfuric acid with a second leaching agent to obtain a first solution; the amount of said concentrated sulfuric acid preferably comprises 0.6-0.8 of the total amount of concentrated sulfuric acid consumed in the leaching process of said calcined burnt clinker. Said second leaching agent may be selected from water or recycled wastewater.

Step 3. Under the stirring state, the first solution is added to the clinker slurry at a uniform speed to obtain the third solution. The time for adding the first solution to the clinker slurry at a uniform speed is controlled and is preferably more than 15 minutes. If the time is too short, it easily leads to excessive local acidity, resulting in an unstable solution system, and vanadium is easily hydrolyzed and precipitated, causing losses. In addition, the time for adding the first solution to the clinker slurry at a uniform speed can be controlled and is 15~25 minutes. The liquid-to-solid mass ratio of the third solution is preferably (2~10):1, more preferably (2-4):1.

Stage 4. The pH of the third solution is controlled to 2.5~3.5, a leaching reaction is performed, and then solid-liquid separation is performed to obtain a vanadium-containing leaching solution and a vanadium extraction tailings. At this stage, the pH can be adjusted using dilute sulfuric acid, and the concentration of dilute sulfuric acid can be controlled at around 50%.

In an embodiment of the present invention, the leaching agent is divided into two parts for use, where one part is used for clinker pulp, one part is used for leaching diluted with concentrated sulfuric acid, and then the leaching agent containing sulfuric acid is added to the clinker pulp, which improves the liquid-solid ratio in the pulp and at the same time realizes rapid leaching of vanadium, and avoids problems in terms of high local acidity, high temperature, high impurity content, etc., which occur when concentrated sulfuric acid is directly added.

The technical solutions of the present invention are described in more detail below using embodiments.

Comparative example 1:

100g of calcined burnt clinker (TV=7.07%, P=0.066%) was taken, 250ml of water was added, and 50% diluted sulfuric acid was used with stirring to adjust the pH of the system to 3.0, and the reaction was carried out for 60 min, and the solid-liquid separation was carried out to obtain a leaching liquid (V=23.82g/L, P=0.03g/L) and vanadium tailings slag (TV=1.14%). The sulfuric acid consumption for the leaching process was 5.5ml of equivalent concentrated sulfuric acid, and the vanadium dissolution rate was 84.84%.

Example 1:

(1) Take 100 g of calcined burnt clinker (TV=7.07%, P=0.066%), add 100 ml of water and mix well to obtain clinker suspension A;

(2) Take 3.3 ml of concentrated sulfuric acid, add 150 ml of water and mix well to obtain solution B;

(3) Solution B was added to clinker slurry A at a uniform rate, the addition time was controlled and was 15 minutes to obtain slurry C. At this time, the liquid to solid ratio of slurry C was 2.53:1;

(4) The pH of suspension C was controlled to 3.0 using 50% dilute sulfuric acid, and after a leaching reaction for 40 min, solid-liquid separation was carried out to obtain a vanadium-containing leaching solution (V=24.22 g/L, P=0.018 g/L) and a vanadium tail (TV=1.05%).

The consumption of sulfuric acid for the leaching process was 5.2 ml of equivalent concentrated sulfuric acid, and the degree of vanadium dissolution was 86.03%.

In general, the liquid-to-solid ratio of the C slurry should be controlled at 2-4:1, mainly to obtain a vanadium leaching solution with a higher vanadium concentration (V>20 g/L), which is convenient for subsequent vanadium precipitation to obtain vanadium oxide products. The liquid-to-solid ratio of the C slurry is the preferred value for actual production based on calcined clinker (TV=6-10%). Theoretically, the liquid-to-solid ratio of this C slurry can be increased to more than 10:1, only to achieve a vanadium concentration of less than 10 g/L.

Comparative example 2:

100 g of calcined burned clinker (TV=8.54%, P=0.058%) were taken, 300 ml of vanadium-containing solution (V=3.15 g/l) were added and 50% diluted sulfuric acid was used with stirring to adjust the pH of the system to 2.8, the reaction was carried out for 80 min, after which solid-liquid separation was carried out to obtain a leaching solution (V=28.31 g/l, P=0.028 g/l) and vanadium tailings slag (TV=1.08%). The sulfuric acid consumption for the leaching process was 6.7 ml of equivalent concentrated sulfuric acid, and the degree of vanadium dissolution was 88.24%.

Example 2:

(1) 100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 100 ml of vanadium-containing solution (V=3.15 g/l) was added and mixed well to obtain clinker suspension A;

(2) Take 5.4 ml of concentrated sulfuric acid, add 200 ml of water, mix well to obtain solution B;

(3) Solution B was added to clinker slurry A at a uniform rate, the addition time was controlled and was 25 minutes to obtain slurry C. At this time, the liquid to solid ratio of slurry C was 3.05:1;

(4) Using 50% dilute sulfuric acid to control the pH of suspension C at 2.8, the leaching reaction was carried out for 60 min, solid liquid separation, vanadium leaching solution (V=28.61 g/L, P=0.020 g/L) and vanadium tailings (TV=0.96%) were obtained.

The consumption of sulfuric acid during the leaching process was 6.6 ml of concentrated sulfuric acid, and the degree of vanadium dissolution was 89.43%.

Comparative example 3:

100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 400 ml of recycled water for wastewater treatment (V=0.1 g/L) was added and 50% diluted sulfuric acid was used with stirring to adjust the pH of the system to 2.5, the reaction was carried out for 80 min, after which solid-liquid separation was carried out to obtain a leaching solution (V=18.57 g/L, P=0.035 g/L) and a vanadium tailings residue (TV=1.21%). The sulfuric acid consumption for the leaching process was 7.1 ml of equivalent concentrated sulfuric acid, and the degree of vanadium dissolution was 86.96%.

Example 3:

(1) 100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 200 ml of reused water for wastewater treatment (V=0.1 g/l) were added, mixed well and clinker suspension A was obtained;

(2) Take 5.5 ml of concentrated sulfuric acid, add 200 ml of water, mix well to obtain solution B;

(3) Solution B was added to clinker slurry A at a uniform rate, and the addition time was controlled and was 25 minutes to obtain slurry C. At this time, the liquid to solid ratio of slurry C was 4.05:1;

(4) The pH of suspension C was controlled at 2.5, 50% dilute sulfuric acid was used, the leaching reaction lasted 40 min, the solid was separated from the liquid, and a vanadium leaching solution (V=19.28/l, P=0.021 g/l) and vanadium tail (TV=0.91%) were obtained.

The consumption of sulfuric acid for the leaching process was 6.8 ml of concentrated sulfuric acid, the degree of vanadium dissolution was 90.19%.

Comparative example 4:

100 g of calcined burned clinker (TV=8.54%, P=0.058%) were taken, 600 ml of vanadium-containing solution (V=3.15 g/l) were added, 50% diluted sulfuric acid was used with stirring to adjust the pH of the system to 2.8, the reaction was carried out for 80 min, after which solid-liquid separation was carried out to obtain a leaching solution (V=15.70 g/l, P=0.021 g/l) and vanadium tailings slag (TV=1.06%). The sulfuric acid consumption for the leaching process was 7.2 ml of equivalent concentrated sulfuric acid, the degree of vanadium dissolution was 88.52%.

Example 4:

(1) 100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 200 ml of vanadium-containing solution (V=3.15 g/l) were added and mixed well to obtain clinker suspension A;

(2) Take 5.8 ml of concentrated sulfuric acid, add 400 ml of water, mix well to obtain solution B;

(3) Solution B was added to clinker slurry A at a uniform rate, and the addition time was controlled and was 25 minutes to obtain slurry C. At this time, the liquid to solid ratio of slurry C was 6.06:1;

(4) Using 50% dilute sulfuric acid to control the pH of suspension C at 2.8, the leaching reaction was carried out for 60 min, the solid liquid was separated, the vanadium leaching solution (V=15.17 g/L, P=0.020 g/L) and the vanadium tail (TV=0.93%) were obtained.

The consumption of sulfuric acid during the leaching process was 6.8 ml of concentrated sulfuric acid, and the degree of vanadium dissolution was 89.82%.

Comparative example 5:

100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 1200 ml of recycled water for wastewater treatment (V=0.1 g/L) was added and 50% diluted sulfuric acid was used with stirring to adjust the pH of the system to 2.8, the reaction was carried out for 80 min, after which solid-liquid separation was carried out to obtain a leaching solution (V=6.31 g/L, P=0.022 g/L) and a vanadium tailings residue (TV=1.04%). The sulfuric acid consumption for the leaching process was 8.0 ml of equivalent concentrated sulfuric acid, and the degree of vanadium dissolution was 88.81%.

Example 5:

(1) 100 g of calcined burnt clinker (TV=8.54%, P=0.058%) were taken, 200 ml of reused water for wastewater treatment (V=0.1 g/l) were added, mixed well and clinker suspension A was obtained;

(2) Take 6.0 ml of concentrated sulfuric acid, add 1000 ml of water, mix well to obtain solution B;

(3) Solution B was added to clinker slurry A at a uniform rate, and the addition time was controlled and was 25 minutes to obtain slurry C. At this time, the liquid to solid ratio of slurry C was 12.06:1;

(4) The pH of suspension C was controlled to 2.8 using 50% dilute sulfuric acid, the leaching reaction lasted for 40 min, after which the solid liquid was separated to obtain a vanadium leaching solution (V=6.58/l, P=0.021 g/l) and vanadium tail (TV=0.90%).

Sulfuric acid consumption during the leaching process was 7.4 ml of equivalent concentrated sulfuric acid, and the vanadium dissolution rate was 90.05%. In this case, the C-liquid-to-solid suspension ratio was higher than 10:1, which was favorable for increasing the vanadium leaching rate. However, the vanadium concentration in the resulting leaching solution was below 8 g/L, which did not facilitate further vanadium extraction to produce vanadium oxide products.

Various embodiments of the present invention have been described in detail to date. To avoid obscuring the spirit of the present invention, certain details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the foregoing description.

Although certain specific embodiments of the present invention have been described in detail using examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that the above embodiments may be modified or some technical features may be equivalently substituted without departing from the scope and spirit of the present invention. In particular, each of the technical features mentioned in the various embodiments may be combined in any manner, provided there are no structural contradictions.

Claims (14)

1. A method for controlling the process of acid leaching of calcined burnt vanadium-containing clinker, characterized in that it includes: stage 1: mixing said calcined burnt clinker with a first leaching agent to obtain a clinker slurry; Step 2: Mixing concentrated sulfuric acid with the second leaching agent to produce the first solution; Stage 3: adding the first solution to the clinker slurry at a uniform rate to obtain the third solution; Stage 4: controlling the pH of the said third solution at 2.5-3.5, carrying out a leaching reaction, and then solid-liquid separation to obtain a vanadium-containing leaching solution and a vanadium extraction tailings slag. 2. A method for controlling the process of acid leaching of calcined burnt clinker according to claim 1, characterized in that in the second stage the amount of said concentrated sulfuric acid is 0.6-0.8 times greater than the total amount of concentrated sulfuric acid consumed in the process of leaching the calcined burnt clinker. 3. A method for controlling the process of acid leaching of calcined fired clinker according to claim 1, characterized in that at the first stage the mass ratio of said calcined fired clinker and all of said first leaching agent is 1:1-2. 4. A method for controlling the process of acid leaching of calcined burnt clinker according to claim 1, characterized in that at the first stage, said first leaching agent is water, reused water for wastewater treatment, or a vanadium-containing solution. 5. A method for controlling the process of acid leaching of calcined burnt clinker according to claim 1, characterized in that in the second stage, said second leaching agent is water or reused water for wastewater treatment. 6. A method for controlling the process of acid leaching of calcined fired clinker according to claim 1, characterized in that in the third stage, said first solution is added to said clinker suspension at a uniform rate for 15 minutes or more. 7. A method for controlling the process of acid leaching of calcined fired clinker according to paragraph 6, characterized in that the time of adding said first solution to said clinker suspension at a uniform rate is 15-25 minutes. 8. A method for controlling the process of acid leaching of calcined fired clinker according to claim 1, characterized in that the mass ratio of liquid to solid in said third solution is (2-10):1; Preferably, the mass ratio of liquid to solid in said third solution is (2-4):1. 9. A method for controlling the process of acid leaching of calcined fired clinker according to claim 4, characterized in that said vanadium-containing solution includes a washing solution of vanadium mining tailings.