阅读说明：本技术 提钒尾渣造球提钒的方法 (Method for pelletizing and extracting vanadium from vanadium extraction tailings ) 是由 郭继科 申彪 李明 蒋霖 于 2020-05-20 设计创作，主要内容包括：本发明属于钒的冶金技术领域,具体涉及提钒尾渣造球提钒的方法。本发明所要解决的技术问题是提供能够降低浸出残渣中钒含量的提钒尾渣造球提钒的方法。该方法包括如下步骤：a、将含钒物料与提钒尾渣混匀,干燥得混合料1；b、混合料1与钠盐混合,得混合料2,以氢氧化钠、粘结剂和水制备粘结溶液,将混合料2与粘结溶液混合,制得湿球团；c、将湿球团烘干,焙烧,浸出。采用本发明方法可使浸出后的残渣中的钒含量可降低至0.3％以下。(The invention belongs to the technical field of vanadium metallurgy, and particularly relates to a method for extracting vanadium by pelletizing vanadium extraction tailings. The invention aims to solve the technical problem of providing a method for extracting vanadium by pelletizing vanadium extraction tailings, which can reduce the content of vanadium in leaching residues. The method comprises the following steps: a. mixing the vanadium-containing material and the vanadium extraction tailings uniformly, and drying to obtain a mixture 1; b. mixing the mixture 1 with sodium salt to obtain a mixture 2, preparing a bonding solution by using sodium hydroxide, a bonding agent and water, and mixing the mixture 2 with the bonding solution to obtain wet pellets; c. and drying, roasting and leaching the wet pellets. The method can reduce the vanadium content in the leached residue to below 0.3 percent.)

1. The method for pelletizing and extracting vanadium from vanadium extraction tailings is characterized by comprising the following steps: the method comprises the following steps:

a. mixing the vanadium-containing material and the vanadium extraction tailings uniformly, and drying to obtain a mixture 1;

b. mixing the mixture 1 with sodium salt to obtain a mixture 2, preparing a bonding solution by using sodium hydroxide, a bonding agent and water, and mixing the mixture 2 with the bonding solution to obtain wet pellets;

c. and drying, roasting and leaching the wet pellets.

2. The method for pelletizing and extracting vanadium from the vanadium extraction tailings according to claim 1, which is characterized by comprising the following steps: in step a, at least one of the following is satisfied:

the vanadium-containing material is sieved by a 120-mesh sieve in a particle size ratio of more than 80 percent;

the vanadium-containing material is at least one of vanadium-titanium magnetite, converter vanadium slag, vanadium-phosphorus iron ore, vanadic soil or vanadium-containing fly ash;

the vanadium extraction tailings are dried sodium salt roasting water extraction vanadium tailings;

the mass content of vanadium in the vanadium extraction tailings is 0.6-1.5%;

drying until the moisture content of the mixture 1 is less than or equal to 5.0 percent;

the mass ratio of the vanadium-containing material to the vanadium extraction tailings is 0-1.0: 1.0.

3. The method for pelletizing and extracting vanadium from the vanadium extraction tailings according to claim 1 or 2, which is characterized by comprising the following steps: in the step b, the sodium salt is at least one of sodium carbonate, sodium bicarbonate, sodium sulfate or sodium chloride.

4. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 3, characterized by comprising the following steps: in the step b, the mixture 1 and sodium salt are mixed according to the mass ratio of the element sodium to the vanadium of 0.8-1.5.

5. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 4, characterized by comprising the following steps: in the step b, the mass ratio of the sodium hydroxide to the binder to the water is 0.1:1.0: 10.0-20.0.

6. The method for pelletizing and extracting vanadium from the vanadium extraction tailings according to claim 5, which is characterized by comprising the following steps: the binder is at least one of humic acid, coal tar, pitch, pulp waste liquid, syrup or starch.

7. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 6, characterized by comprising the following steps: in the step b, the water content of the wet pellets is 15-20%; the particle size of the wet pellets is 10-30 mm.

8. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 7, characterized by comprising the following steps: in step c, the wet pellets are dried until the water content is less than or equal to 4%.

9. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 8, characterized by comprising the following steps: in the step c, the roasting temperature is 800-870 ℃; the roasting time is 30-60 min.

10. The method for pelletizing and extracting vanadium from vanadium extraction tailings according to any one of claims 1 to 9, characterized by comprising the following steps: in step c, at least one of the following is satisfied:

crushing the roasted clinker until the granularity is larger than 80 percent of the roasted clinker, and sieving the clinker by a 120-mesh sieve;

leaching the roasted clinker and water according to a liquid-solid ratio of 1: 1-3: 1 mL/g;

the leaching temperature is 80-95 ℃; the leaching time is 20-30 min.

Technical Field

The invention belongs to the technical field of vanadium metallurgy, and particularly relates to a method for extracting vanadium by pelletizing vanadium extraction tailings.

Background

The converter vanadium slag is a main raw material for producing vanadium oxide, the traditional process for extracting vanadium from the converter vanadium slag is vanadium slag-sodium roasting-hot water leaching vanadium extraction, the obtained leachate is used for precipitating vanadium by acidic ammonium salt, part of the obtained leaching tailings returns to a roasting system, and part of the leaching tailings continues to extract vanadium deeply. In order to realize the deep vanadium extraction of the tailings, domestic and foreign production enterprises and scientific research units research the secondary sodium salt roasting fire method of the tailings and wet methods of high-acid leaching, pressure oxidation acid leaching, alkali leaching and the like of the tailings.

Patent document CN109825723A discloses a method for deep extraction of vanadium by using alkaline tailings, which directly mixes the alkaline tailings as a raw material with a vanadium-containing material to perform a roasting reaction-water leaching extraction of vanadium; patent document CN107586948A discloses a method for deep extraction of vanadium from vanadium slag, in which vanadium slag and sodium carbonate are roasted and then soaked in water, tailings are soaked in acid, and the obtained two solutions are mixed to extract vanadium.

Compared with the traditional vanadium slag vanadium extraction process, the tailings deep vanadium extraction process still has two technical problems, one is that the vanadium in the tailings can be only reduced to about 0.6 percent from about 1.0 percent, the vanadium extraction rate is low, and the residual vanadium content in the tailings is high; secondly, in order to realize high extraction rate of vanadium in the tailings, adding other vanadium-containing materials to mix with the tailings, increasing roasting temperature and adding sodium salt additive are effective means, but when the roasting temperature is higher than 780 ℃, low-melting-point phase is easy to appear in roasting equipment, so that the materials are bonded and agglomerated, the working condition of the equipment is worsened, and the roasting conversion rate is reduced.

In order to solve the contradiction between the high extraction rate of vanadium and the working condition of equipment, the vanadium content in the roasting raw materials is reduced, the roasting temperature is reduced, and the roasting time is prolonged in the industry, but the contradiction can be relieved, the operation efficiency is reduced, and the extraction rate of vanadium is still low.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for extracting vanadium by pelletizing vanadium extraction tailings, which can reduce the content of vanadium in leaching residues.

The invention adopts the technical scheme to solve the technical problems and provides a method for extracting vanadium by pelletizing vanadium extraction tailings, which comprises the following steps:

a. mixing the vanadium-containing material and the vanadium extraction tailings uniformly, and drying to obtain a mixture 1;

b. mixing the mixture 1 with sodium salt to obtain a mixture 2, preparing a bonding solution by using sodium hydroxide, a bonding agent and water, and mixing the mixture 2 with the bonding solution to obtain wet pellets;

c. and drying, roasting and leaching the wet pellets.

In the method for pelletizing and extracting vanadium from the vanadium extraction tailings, in the step a, the particle size of the vanadium-containing material is more than 80 percent of that of the vanadium-containing material passing through a 120-mesh sieve.

Further, the vanadium-containing material is at least one of vanadium titano-magnetite, converter vanadium slag, vanadium-phosphorus iron ore, vanadium soil or vanadium-containing fly ash.

Further, the vanadium extraction tailings are dried sodium salt roasting water extraction vanadium tailings.

Further, the mass content of vanadium in the vanadium extraction tailings is 0.6-1.5%.

Further, the drying is carried out until the moisture content of the mixed material 1 is less than or equal to 5.0 percent.

Further, the mass ratio of the vanadium-containing material to the vanadium extraction tailings is 0-1.0: 1.0.

In the method for pelletizing and extracting vanadium from the vanadium extraction tailings, in the step b, the sodium salt is at least one of sodium carbonate, sodium bicarbonate, sodium sulfate or sodium chloride.

Preferably, the sodium salt is sodium carbonate.

Further, the mixture 1 and the sodium salt are mixed according to the mass ratio of the element sodium to the vanadium of 0.8-1.5.

Further, the mass ratio of the sodium hydroxide to the binder to the water is 0.1:1.0: 10.0-20.0.

Further, the binder is at least one of humic acid, coal tar, pitch, pulp waste liquor, syrup or starch.

Further, the moisture content of the wet pellets is 15-20%; the particle size of the wet pellets is 10-30 mm.

In the method for pelletizing and extracting vanadium from the vanadium extraction tailings, in the step c, the wet pellets are dried until the water content is less than or equal to 4%.

Further, the roasting temperature is 800-870 ℃; the roasting time is 30-60 min.

Furthermore, the roasted clinker is crushed until the granularity is larger than 80 percent of the clinker passing through a 120-mesh sieve.

Further, the roasted clinker and water are leached according to the liquid-solid ratio of 1: 1-3: 1 mL/g.

Further, the leaching temperature is 80-95 ℃; the leaching time is 20-30 min.

The invention has the beneficial effects that:

the method takes tailings of vanadium slag subjected to sodium salt roasting-water vanadium extraction as a raw material, and performs pelletizing, drying and high-temperature roasting to recover residual vanadium, and after powdery vanadium slag is prepared into spherical vanadium slag blocks, main low-melting-point phases formed in the roasting process are fixed in the pellets, so that the material adhesion phenomenon is controlled, roasting equipment is stable and controllable, the vanadium content in the leached residues can be reduced to be below 0.3%, and the roasting time is greatly reduced.

Detailed Description

Specifically, the invention provides a method for pelletizing and extracting vanadium from vanadium extraction tailings, which comprises the following steps:

a. uniformly mixing the vanadium-containing material and the dried sodium-roasting water-leaching vanadium extraction tailings according to the mass ratio of 0-1.0: 1.0, and drying to obtain a mixture 1 with the water content of less than or equal to 5.0%;

b. mixing the mixture 1 with sodium salt according to the mass ratio of the element sodium to the element vanadium of 0.8-1.5 to obtain a mixture 2, preparing a binding solution from sodium hydroxide, a binder and water according to the mass ratio of 0.1:1.0: 10.0-20.0, and mixing the mixture 2 with the binding solution to obtain wet pellets with the water content of 15-20% and the particle size of 10-30 mm;

c. and drying the wet pellets until the water content is less than or equal to 4%, roasting at 800-870 ℃ for 30-60 min, and leaching the roasted clinker and water at 80-95 ℃ for 20-30 min according to a liquid-solid ratio of 1: 1-3: 1 mL/g.

In the step a of the invention, the water content of the mixture 1 is controlled to be below 5.0 percent, because a sufficient amount of the bonding solution needs to be added when the mixture 1 is pressed into the ball, if the water content of the mixture 1 is too high, the addition amount of the bonding solution is limited, the bonding solution is easy to adhere to a die and is difficult to demould when the addition amount of the bonding solution is too high, the compression strength of the ball is low and the ball is difficult to form when the addition amount of the bonding solution is too low, and in addition, the water content of the mixture 1 is too high, and the material is easy to agglomerate when sodium salt.

In the step b, the mixture 1 and sodium salt are mixed according to the mass ratio of the element sodium to the vanadium of 0.8-1.5, wherein the mass ratio of the sodium to the vanadium is converted into the mass ratio of the sodium oxide to the vanadium pentoxide in the vanadium slag. In order to ensure that vanadium can be effectively converted into sodium vanadate, the mass ratio of sodium to vanadium is controlled within the range.

In the step b, the sodium hydroxide, the binder and the water are prepared into the binding solution according to the mass ratio of 0.1:1.0: 10.0-20.0, so that the sodium hydroxide and the binder are fully reacted in the aqueous solution, and the binding solution can ensure certain viscosity and is favorable for pelletizing.

In the step b, in order to facilitate pelletizing, the moisture content of the wet pellets is controlled to be 15-20%, the moisture content is too low, pelletizing is difficult, and the pulverization rate is high in the pelletizing process; the water content is too high, the pelletizing is difficult, the compression strength of the pellets is low, and the drying difficulty is increased.

In the step c of the invention, the wet pellets can be roasted by adopting material dynamic roasting equipment, such as a multi-hearth furnace and a rotary kiln, and can also be roasted by adopting material static roasting equipment, such as a muffle furnace, a rotary furnace and a sintering machine.

According to the method, the vanadium extraction tailings are prepared into the pellets, the tailings or clinker are prevented from being added in the roasting process, the reaction heat is basically consumed by the internal reaction of the pellets in the roasting process in the pellet roasting mode, the low-melting-point phase is fixed in the pellets, the chemical reaction is sufficient, the contact surface between the pellets is small, and the bonding probability is greatly reduced.

According to the method, the roasting temperature is controlled to be 800-870 ℃, the vanadium-containing phase in the tailings is favorably damaged, the oxidation reaction and the sodium treatment reaction speed are accelerated, in the reaction process, low-valence vanadium in ferrovanadium spinel is oxidized into high-valence vanadium and then reacts with sodium salt to form water-soluble vanadate, the low-valence vanadium in other phases and the high-valence vanadium phase wrapped in the tailings can also react with the sodium salt under the high-temperature oxidation condition, the vanadium conversion rate in the roasting process can reach about 92%, and the vanadium content in the leached residues of the obtained clinker is lower than 0.3%.

The invention is further illustrated by the following examples.