A vanadium conversion agent and its preparation method and application, and a method for extracting vanadium

Abstract

The present invention belongs to the field of metallurgical technology, and specifically relates to a vanadium conversion agent and its preparation method and application, and a method for extracting vanadium. When the vanadium conversion agent provided by the present invention is used to extract vanadium from vanadium-containing materials, it has good adhesion and affinity with vanadium-containing material powder. During the roasting process, the low-valent vanadium inside the vanadium-containing material begins to be converted into pentavalent vanadium. The carbon dioxide gas generated by the decomposition of sodium bicarbonate and the expansion of silicon can make the pellet material produce a loose porous structure, increase its contact area with oxygen, effectively improve the reaction efficiency, shorten the reaction time, and improve the vanadium conversion rate; moreover, the vanadium pentoxide in the vanadium conversion agent further induces the low-valent vanadium to be converted into pentavalent vanadium, so that the low-valent vanadium in the vanadium-containing material has a high conversion rate and a high leaching rate under the action of the vanadium conversion agent, so that the vanadium conversion rate can reach more than 90%.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a vanadium conversion agent and a preparation method and application thereof, and a method for extracting vanadium. Background Art

[0002] As an extremely important industrial raw material, vanadium and vanadium-containing compounds have broad application prospects in many fields such as steel, alloys, chemicals, medicines, catalysis, new pigments and battery technology. At present, the market demand for vanadium and vanadium-containing compounds increases year by year, and is in a situation of supply exceeding demand. In vanadium ore, most of the vanadium enters the mineral lattice in a trivalent state. This type of lattice structure is very stable, and the vanadium is in a bound state and is difficult to be dissolved and leached by water, acid or alkali. Therefore, to leach this part of vanadium, it is necessary to first destroy these stable lattice structures, release the vanadium bound in the lattice structure, and then oxidize and convert it. Chinese patent CN108034807A discloses a conversion agent for extracting vanadium from vanadium ore and a method of using the same, which includes vanadium silicide, vanadium pentoxide and methyl red sodium salt. The conversion agent can be used as the roasting and conversion oxidation of various vanadium ores, has strong adaptability, fast vanadium conversion speed and high conversion rate, but methyl red sodium salt is toxic, which increases production risks. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a vanadium conversion agent and its preparation method and application, and a method for extracting vanadium. The vanadium conversion agent provided by the present invention can improve the conversion rate of vanadium in vanadium-containing materials, and is safe and low-cost.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a vanadium conversion agent, which comprises the following components by weight:

[0006] 80-90 parts of vanadium silicide, 2-6 parts of vanadium pentoxide, and 10-20 parts of sodium bicarbonate.

[0007] Preferably, the vanadium conversion agent comprises the following components in parts by mass: 82-89 parts of vanadium silicide, 3-5 parts of vanadium pentoxide, and 12-18 parts of sodium bicarbonate.

[0008] The present invention also provides a method for preparing the vanadium conversion agent described in the above technical solution, comprising the following steps:

[0009] Vanadium silicide, vanadium pentoxide and sodium bicarbonate are mixed and crushed to obtain a vanadium conversion agent.

[0010] Preferably, the mixing is carried out under stirring conditions; the stirring speed is 90 to 120 rpm.

[0011] Preferably, the crushing is grinding; the particle size of the vanadium conversion agent obtained by the crushing is 60 to 80 meshes.

[0012] The present invention also provides the use of the vanadium conversion agent described in the above technical solution or the vanadium conversion agent prepared by the preparation method described in the above technical solution in vanadium extraction.

[0013] The present invention also provides a method for extracting vanadium, comprising the following steps:

[0014] Mixing vanadium-containing material powder and vanadium conversion agent, adding water to the obtained mixture to make pellets, and obtaining pellets;

[0015] The pellet material is sequentially subjected to roasting, leaching, extraction, precipitation and decomposition to obtain vanadium pentoxide;

[0016] The vanadium conversion agent is the vanadium conversion agent described in the above technical solution or the vanadium conversion agent prepared by the preparation method described in the above technical solution.

[0017] Preferably, the mass ratio of the vanadium-containing powder to the vanadium conversion agent is 3-6:94-97.

[0018] Preferably, the particle size of the vanadium-containing powder is 60-100 meshes.

[0019] Preferably, the calcination temperature is 270-850° C. and the calcination time is 3-4 hours.

[0020] The invention provides a vanadium conversion agent, which comprises the following components by weight: 80-90 parts of vanadium silicide, 2-6 parts of vanadium pentoxide and 10-20 parts of sodium bicarbonate. When the vanadium converter provided by the present invention is used to extract vanadium from vanadium-containing materials, the vanadium converter and vanadium-containing material powder are made into pellets. The vanadium converter has good adhesion and affinity. During the roasting process, under the action of the vanadium converter, low-valent vanadium in the vanadium-containing material begins to be converted into pentavalent vanadium, and carbon dioxide gas generated by the initial decomposition of sodium bicarbonate will cause salt explosion in the pellets, so that a honeycomb shape appears in the pellets. At the same time, the expansion of silicon increases the volume of the pellets. With the increase of the roasting temperature, the carbon dioxide gas generated by the decomposition of sodium bicarbonate continues to increase the volume of the pellets, and the obtained loose and porous pellets can increase the contact area between the pellets and oxygen, effectively improve the reaction efficiency, shorten the reaction time, and further improve the conversion rate of vanadium. Moreover, the vanadium pentoxide in the vanadium converter further induces the low-valent vanadium to be converted into pentavalent vanadium, so that the low-valent vanadium in the vanadium ore has a high conversion rate and a high leaching rate under the action of the vanadium converter, and the vanadium conversion rate can reach more than 90%. In addition, the vanadium conversion agent of the present invention can coexist with the vanadium-containing powder for a long time, and will not produce a reduction reaction on the converted and leached pentavalent vanadium even at high temperature. Moreover, the sodium bicarbonate in the vanadium conversion agent provided by the present invention is cheaper, more widely available, safer and more reliable than methyl red sodium salt, which effectively improves the economic benefits of the enterprise. DETAILED DESCRIPTION

[0021] The present invention provides a vanadium conversion agent, characterized in that it comprises the following components by mass:

[0022] 80-90 parts of vanadium silicide, 2-6 parts of vanadium pentoxide, and 10-20 parts of sodium bicarbonate.

[0023] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0024] The vanadium conversion agent provided by the present invention comprises 80 to 90 parts by mass of vanadium silicide (VSi2), preferably 82 to 89 parts by mass.

[0025] Based on 1 mass part of vanadium silicide in the vanadium conversion agent, the vanadium conversion agent provided by the present invention includes 2 to 6 parts of vanadium pentoxide (V2O5), and more preferably 3 to 5 parts.

[0026] Based on 1 mass part of vanadium silicide in the vanadium conversion agent, the vanadium conversion agent provided by the present invention includes 10 to 20 parts of sodium bicarbonate (baking soda), and more preferably 12 to 18 parts.

[0027] The present invention also provides a method for preparing the vanadium conversion agent described in the above technical solution, comprising the following steps:

[0028] Vanadium silicide, vanadium pentoxide and sodium bicarbonate are mixed and crushed to obtain a vanadium conversion agent.

[0029] The invention mixes vanadium silicide, vanadium pentoxide and sodium bicarbonate to obtain a mixed raw material.

[0030] In the present invention, the mixing is preferably carried out under stirring conditions; the stirring speed is preferably 90 to 120 rpm, more preferably 90 to 100 rpm; and the mixing is preferably carried out under normal temperature and pressure conditions.

[0031] The present invention has no particular limitation on the mixing process, and any mixing process known in the art may be used.

[0032] After obtaining the mixed raw material, the present invention crushes the mixed raw material to obtain a vanadium conversion agent.

[0033] In the present invention, the crushing is preferably grinding; the particle size of the vanadium conversion agent obtained by the crushing is preferably 60-80 meshes, more preferably 70-80 meshes; the crushing is preferably carried out under normal temperature and pressure.

[0034] The present invention also provides the use of the vanadium conversion agent described in the above technical solution or the vanadium conversion agent prepared by the preparation method described in the technical solution in vanadium extraction.

[0035] The present invention also provides a method for extracting vanadium, comprising the following steps:

[0036] Mixing vanadium-containing material powder and vanadium conversion agent, adding water to the obtained mixture to make pellets, and obtaining pellets;

[0037] The pellet material is sequentially subjected to roasting, leaching, extraction, precipitation and decomposition to obtain vanadium pentoxide;

[0038] The vanadium conversion agent is the vanadium conversion agent described in the above technical solution or the vanadium conversion agent prepared by the preparation method described in the above technical solution.

[0039] The present invention mixes vanadium-containing material powder and a vanadium conversion agent to obtain a mixed material.

[0040] In the present invention, the mass ratio of the vanadium-containing powder to the vanadium conversion agent is preferably 3-6:94-97, more preferably 3-5:95-97.

[0041] In the present invention, the particle size of the vanadium-containing powder is preferably 60-100 mesh, more preferably 80-100 mesh; the vanadium-containing powder is preferably obtained by crushing the vanadium-containing material; the crushing equipment is preferably a crusher; the vanadium-containing material preferably includes one or more of vanadium slag, vanadium-containing stone coal, vanadium oxide mud and vanadium-containing industrial waste, more preferably vanadium-containing stone coal. When the vanadium-containing material is the above multiple types, the present invention has no special restrictions on the ratio of different types of vanadium-containing materials, and any ratio can be used.

[0042] In the present invention, the vanadium content of the vanadium-containing stone coal is preferably 0.8-16wt.%, more preferably 0.8-1wt.% or 14-16wt.%; the vanadium content of the vanadium-containing industrial waste is preferably 3-8wt.%.

[0043] In the present invention, the mixing is preferably performed under stirring conditions; the stirring speed is preferably 90 to 120 rpm, more preferably 100 to 120 rpm.

[0044] After obtaining the mixed material, the present invention adds water to the mixed material to make balls, thereby obtaining pellets.

[0045] The present invention has no special limitation on the amount of water added, and the amount of water added can be selected according to actual needs.

[0046] The present invention has no particular limitation on the process of making the balls, and any ball making process known in the art may be used.

[0047] In the present invention, the diameter of the pellets is preferably 4 to 5 cm, more preferably 4 to 4.5 cm.

[0048] After obtaining the pellets, the present invention bakes the pellets.

[0049] In the present invention, the calcination temperature is preferably 270 to 850° C., more preferably 300 to 800° C.; the calcination time is preferably 3 to 4 hours, more preferably 3 to 3.5 hours.

[0050] In the present invention, the calcination comprises: first heating from room temperature to a first temperature, and keeping the temperature for the first calcination; and second heating from the first temperature to a second temperature, and keeping the temperature for the second calcination.

[0051] In the present invention, the first temperature is preferably 270-350°C, more preferably 270-300°C; the first calcination time is preferably 1-2h, more preferably 1-1.5h; the first heating rate is preferably 2.5-4°C / min, more preferably 3-4°C / min.

[0052] In the present invention, the second temperature is preferably 350-850°C, more preferably 600-850°C; the second calcination time is preferably 1-2h, more preferably 1-1.5h; the second heating rate is preferably 5.5-10°C / min, more preferably 9-10°C / min.

[0053] In the present invention, the diameter of the pellets after the first calcination is preferably increased to 6-7 cm, and the diameter of the pellets after the second calcination is preferably increased to 7-8 cm.

[0054] After the calcination, the present invention preferably cools the calcined product to room temperature to obtain a calcined material. In the present invention, the cooling is preferably natural cooling or blower cooling, more preferably natural cooling.

[0055] The present invention mixes vanadium-containing material powder and a vanadium converter to prepare a pellet material. The vanadium converter has excellent adhesion and affinity. During the roasting process, when the temperature rises to a first temperature, under the action of the vanadium converter, low-valent vanadium in the vanadium-containing material begins to be converted, and sodium bicarbonate begins to preliminarily decompose to generate carbon dioxide. The carbon dioxide gas generated by high-temperature decomposition causes salt explosion in the pellet, so that a honeycomb shape appears in the pellet, and the expansion of silicon increases the volume of the pellet; when the temperature rises to a second temperature, sodium carbonate generated by the decomposition of sodium bicarbonate further decomposes to generate carbon dioxide, so that the volume of the pellet continues to increase. The loose and porous nature of the pellet increases the contact area between the pellet and oxygen, which can effectively improve the reaction efficiency, shorten the reaction time, and further improve the conversion rate of vanadium; the vanadium pentoxide in the vanadium converter further induces low-valent vanadium to be converted into pentavalent vanadium. Under the action of the vanadium converter, the low-valent vanadium in the vanadium-containing material has a fast conversion speed and a high leaching rate, and the vanadium conversion rate can reach more than 90%. In addition, the vanadium conversion agent of the present invention can coexist with the vanadium-containing material powder for a long time, and will not reduce the converted and leached pentavalent vanadium even at high temperature.

[0056] After obtaining the calcined material, the present invention sequentially leaches, extracts, precipitates and decomposes the calcined material to obtain vanadium pentoxide.

[0057] The present invention has no particular limitation on the leaching, extraction, precipitation and decomposition processes, and any leaching, extraction, precipitation and decomposition processes known in the art may be used.

[0058] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0059] Example 1

[0060] 90 parts of vanadium silicide (VSi2), 5 parts of vanadium pentoxide (V2O5) and 15 parts of sodium bicarbonate (baking soda) were stirred at 90 rpm at room temperature and pressure, and then ground to obtain a vanadium conversion agent (particle size of 80 mesh);

[0061] 97 kg of vanadium-containing stone coal (containing 0.8 to 1 wt.%) was weighed and crushed to a particle size of 100 meshes, and 3 kg of the above-mentioned vanadium conversion agent was added, that is, the addition amount was 3%. After stirring evenly at 90 rpm, water was added to form pellets with a diameter of 4 to 5 cm. The temperature was first increased from room temperature to 270°C at a rate of 4°C, and then roasted for 2 hours. After the volume of the pellets increased to a diameter of 6 to 7 cm, the temperature was further increased to 850°C at a rate of 10°C and roasted for 2 hours. The volume of the pellets continued to increase to a diameter of 7 to 8 cm. After the color of the pellets turned grayish white, they were cooled to room temperature, and then conventional leaching, extraction, precipitation and decomposition were carried out to obtain vanadium pentoxide. The vanadium conversion rate was measured to be 95% according to YB / T5304-2006.

[0062] Example 2

[0063] 89 parts of vanadium silicide (VSi2), 3.5 parts of vanadium pentoxide (V2O5) and 10 parts of sodium bicarbonate (baking soda) were stirred at 90 rpm at normal temperature and pressure, and then ground to obtain a vanadium conversion agent (particle size of 80 mesh);

[0064] 94 kg of vanadium-containing stone coal (containing 14-16 wt.%) was weighed and crushed to a particle size of 100 meshes, and 6 kg of the above-mentioned vanadium conversion agent was added, that is, the addition amount was 6%. After stirring evenly at 120 rpm, water was added to form pellets with a diameter of 4-5 cm. The temperature was first increased from room temperature to 270° C. at a rate of 4° C., and then roasted for 2 h. After the volume of the pellets increased to a diameter of 6-7 cm, the temperature was then increased to 850° C. at a rate of 10° C. and roasted for 2 h. The volume of the pellets continued to increase to a diameter of 7-8 cm. After the color of the pellets turned grayish white, they were cooled to room temperature, and then conventional leaching, extraction, precipitation and decomposition were carried out to obtain vanadium pentoxide. The vanadium conversion rate measured according to YB / T5304-2006 was 95%.

[0065] Example 3

[0066] 90 parts of vanadium silicide (VSi2), 4 parts of vanadium pentoxide (V2O5) and 11 parts of sodium bicarbonate (baking soda) were stirred at 90 rpm at room temperature and pressure, and then ground to obtain a vanadium conversion agent (particle size of 80 mesh);

[0067] 90 kg of vanadium-containing stone coal (containing 0.8 to 1 wt.%) and 6 kg of vanadium-containing industrial waste (containing 3 to 8%) were weighed and crushed to a particle size of 100 meshes, and then 4 kg of the above-mentioned vanadium conversion agent was added, i.e., the addition amount was 4%. After being stirred evenly at 90 rpm, water was added to form pellets with a diameter of 4 to 5 cm. The pellets were heated from room temperature to 270° C. at a rate of 4° C., and then roasted for 2 h. After the pellet volume increased to a diameter of 6 to 7 cm, the pellets were heated to 850° C. at a rate of 10° C. and roasted for 2 h. The pellet volume continued to increase to a diameter of 7 to 8 cm. After the pellet color changed to grayish white, the pellets were cooled to room temperature, and then conventional leaching, extraction, precipitation and decomposition were carried out to obtain vanadium pentoxide. The vanadium conversion rate measured according to YB / T5304-2006 was 94%.

[0068] Comparative Example 1

[0069] The difference from Example 1 is that the vanadium conversion agent is 85 parts of vanadium silicide, 2 parts of vanadium pentoxide and 8 parts of methyl red sodium salt, and the rest of the contents are the same as Example 1. According to YB / T5304-2006, the vanadium conversion rate in Comparative Example 1 is 93%.

[0070] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for extracting vanadium, characterized in that: The following steps are involved: Mixing vanadium-containing material powder and vanadium conversion agent, adding water to the obtained mixture to make pellets, and obtaining pellets; The pellet material is sequentially subjected to roasting, leaching, extraction, precipitation and decomposition to obtain vanadium pentoxide; The vanadium conversion agent comprises the following components in parts by mass: 80-90 parts of vanadium silicide, 2-6 parts of vanadium pentoxide, 10-20 parts of sodium bicarbonate; The roasting comprises: first heating from room temperature to a first temperature, and then maintaining the temperature for the first roasting; The second heating is from the first temperature to the second temperature, and the temperature is kept to perform the second roasting; The first temperature is 270-350°C; the first calcination time is 1-2h; the heating rate of the first heating is 2.5-4°C / min; The second temperature is 350-850° C.; the second calcination time is 1-2 hours; and the heating rate of the second heating is 5.5-10° C. / min.

2. The method according to claim 1, characterized in that The vanadium conversion agent comprises the following components in parts by mass: 82-89 parts of vanadium silicide, 3-5 parts of vanadium pentoxide, and 12-18 parts of sodium bicarbonate.

3. The method according to claim 1 or 2, characterized in that The preparation method of the vanadium conversion agent comprises the following steps: Vanadium silicide, vanadium pentoxide and sodium bicarbonate are mixed and crushed to obtain a vanadium conversion agent.

4. The method according to claim 3, characterized in that The mixing is carried out under stirring conditions; the stirring speed is 90-120 rpm.

5. The method according to claim 3, characterized in that: The crushing is grinding; the particle size of the vanadium conversion agent obtained by crushing is 60 to 80 meshes.

6. The method according to claim 1, characterized in that The mass ratio of the vanadium-containing powder to the vanadium conversion agent is 3-6:94-97.

7. The method according to claim 1 or 6, characterized in that: The particle size of the vanadium-containing powder is 60-100 meshes.