Vanadium slag pretreatment desiliconization method

Abstract

The invention discloses a vanadium slag pretreatment desiliconization method which comprises the following steps: adding an alkaline solution into vanadium slag, and uniformly stirring and mixing to enable material liquid to be in full contact; heating, stirring and reacting in a water bath kettle, reacting silicon in the vanadium slag with an alkali solution, and entering the solution from the vanadium slag; the slurry is subjected to solid-liquid separation, the liquid is silicon-containing alkali liquor, and the solid is desiliconized wet vanadium slag; and drying the wet vanadium slag in a drying oven, and grinding by a ball mill to obtain the desiliconized vanadium slag. Compared with an existing vanadium slag pretreatment desiliconization method, the method has the advantages that only the alkaline solution is used for desiliconization, other impurities are not introduced in the desiliconization process, the amount of tailings in the later period is small, and environmental benefits are good.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and more specifically, relates to a method for pre-treating and desiliconizing vanadium slag. Background Art

[0002] Vanadium is an important nonferrous metal, which is widely used in metallurgy, chemical industry, atomic energy and aviation. Vanadium slag is an important vanadium resource, and more than 85% of vanadium products are obtained from vanadium slag. At present, the vanadium extraction processes include sodium roasting-water leaching vanadium extraction, blank roasting-low acid vanadium extraction, calcium roasting-sulfuric acid leaching, direct acid leaching, etc. However, in addition to the main vanadium iron and manganese, vanadium slag also contains 3% to 17% silicon, and the presence of silicon often increases the amount of sodium salt added during the roasting process, the stability of the roasting process is difficult to control, the vanadium conversion rate is low during direct acid leaching, and the silicon in the subsequent vanadium products is difficult to remove. Therefore, pre-treatment of vanadium slag and removal of silicon in vanadium slag before vanadium extraction can effectively solve the above problems and obtain better economic benefits.

[0003] Currently, there are few methods for pretreatment and desiliconization of vanadium slag, and most of them have complex processes, are difficult to operate, and are costly, and have not been industrially commercialized.

[0004] Patent CN102329954A discloses a method for pre-treating converter vanadium slag by alkaline leaching and desiliconization under the action of an electric field, wherein the vanadium slag is mixed with sodium hydroxide and calcium fluoride to form a slurry, which is then leached in a leaching tank with electrodes, followed by solid-liquid separation, and finally the desiliconized vanadium slag is obtained. Patent CN108130425A discloses a method for pre-treatment desiliconization and medium circulation of vanadium slag, wherein the vanadium slag is wet-milled with a calcium-containing material and an alkaline medium, and the obtained slurry is subjected to flotation desiliconization to obtain a desiliconized refined vanadium slag. The above two methods have a long process flow, a complex process, and both use calcium-containing materials, which will increase the final amount of waste slag and increase the industrial production cost.

[0005] The above existing technologies for pretreatment of vanadium slag for removing silicon still cannot meet the demand for desiliconization of vanadium slag in actual industrial production. Summary of the invention

[0006] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0007] In order to achieve these purposes and other advantages according to the present invention, a method for pretreatment and desiliconization of vanadium slag is provided, comprising the following steps:

[0008] Step 1, adding alkaline solution to the powdered vanadium slag passed through a 200-mesh sieve, stirring to make them fully contact, to prepare a slurry;

[0009] Step 2: heating the slurry in a water bath, stirring the reaction, and then separating the solid and the liquid to obtain a filter residue;

[0010] Step 3: drying the filter residue in an oven to constant weight; then grinding the filter residue evenly with a ball mill and passing it through a 200-mesh sieve to obtain desiliconized vanadium slag for subsequent vanadium extraction.

[0011] Preferably, in step 1, the content of vanadium in the vanadium slag as V2O5 is 8wt% to 12wt%, the content of silicon in the vanadium slag as SiO2 is 3% to 17%, and the alkaline solution is a sodium hydroxide solution with a concentration of 50% to 80%.

[0012] Preferably, in step 1, the solid-liquid ratio of the vanadium slag to the alkaline solution is 1-2:3-4.

[0013] Preferably, in step 2, the water bath heating temperature is 60° C. to 90° C., the stirring speed is 150 r / min to 300 r / min, and the reaction time is 30 to 180 min.

[0014] Preferably, in the step 2, a multifunctional vacuum filter is used for filtration during solid-liquid separation.

[0015] Preferably, in step three, the oven temperature is set to 95°C to 105°C.

[0016] Preferably, in the step three, a ball milling medium is added during ball milling, the ball milling medium is a steel ball, the ball milling speed is 60 to 120 rpm, and the ball milling time is 2 to 6 hours.

[0017] Preferably, after the filter residue is ball-milled in step three, the filter residue is subjected to secondary desiliconization, and the specific method is: the ball-milled filter residue is soaked in water, and then ferric chloride solution and polyacrylamide solution are added thereto, and then ultrasonic treatment is performed, and after the treatment, the solid-liquid separation is performed, and the solid is placed in an oven again to be dried to constant weight to obtain the desiliconized vanadium slag for subsequent vanadium extraction.

[0018] Preferably, the water immersion temperature is 75-100° C., the filter residue is completely immersed in the water, the mass ratio of the filter residue, ferric chloride and polyacrylamide is 2:0.05-0.1:0.05-0.1, the ultrasonic frequency is 25 kHz, and the ultrasonic treatment is carried out for 30-90 minutes.

[0019] The present invention has at least the following beneficial effects:

[0020] (1) Compared with the existing vanadium slag pretreatment desiliconization method, the present invention only uses sodium hydroxide and does not introduce calcium-containing media, thereby reducing the subsequent tailings discharge and solid waste discharge, having good environmental benefits, and does not introduce other impurities during the pretreatment process, which facilitates the subsequent impurity removal of the vanadium slag;

[0021] (2) Compared with the existing method of pre-treatment and desiliconization of vanadium slag, the process flow of the present invention is simple, and only heating and stirring, followed by filtering and drying are required to obtain the desiliconized vanadium slag, and the desiliconization effect is good, which has advantages in industrial application.

[0022] (3) The present invention can also perform secondary desiliconization on the filter residue after desiliconization by water immersion, thereby further reducing the silicon content in the vanadium slag without introducing new impurities.

[0023] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention.

[0024] Description of the drawings: Figure 1 This is a schematic diagram of a method for pretreatment and desiliconization of vanadium slag according to the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] Example 1

[0027] A method for pretreatment and desiliconization of vanadium slag, comprising the following steps:

[0028] Step 1, take 150g of powdered vanadium slag through a 200 mesh sieve, the vanadium content in the vanadium slag is 10.63wt% as V2O5, and the silicon content in the vanadium slag is 7.38wt% as SiO2, slowly add 300mL of 50% sodium hydroxide solution to the vanadium slag, and stir and mix well to prepare a slurry;

[0029] Step 2: introduce the ore slurry into a glass container, heat it in a water bath and stir it for reaction, the water bath temperature is 95°C, the stirring speed is 160r / min, and the stirring reaction time is 120min; the fully reacted ore slurry is vacuum filtered to separate the solid and liquid to obtain filter residue and filtrate, and the filtrate can be used for desiliconization treatment again;

[0030] Step 3: Place the obtained filter residue in an oven and dry it at 105°C to constant weight. Grind the dried vanadium residue with steel balls in a ball mill at a grinding speed of 80 rpm for 45 minutes. After grinding evenly, pass it through a 200-mesh sieve to obtain the desiliconized vanadium residue for subsequent vanadium extraction.

[0031] The content of vanadium in the desiliconized vanadium slag is 10.16wt% as V2O5, and the content of silicon in the vanadium slag is 0.31wt% as SiO2.

[0032] Example 2

[0033] A method for pretreatment and desiliconization of vanadium slag, comprising the following steps:

[0034] Step 1, take 200g of powdered vanadium slag through a 200 mesh sieve, the vanadium content in the vanadium slag is 10.12wt% as V2O5, and the silicon content in the vanadium slag is 8.34wt% as SiO2, slowly add 300mL of 50% sodium hydroxide solution to the vanadium slag, and stir and mix well to prepare a slurry;

[0035] Step 2: Pour the ore slurry into a glass container, heat it in a water bath and stir it for reaction. The water bath temperature is 75°C, the stirring speed is 150r / min, and the stirring reaction time is 120min. The fully reacted ore slurry is vacuum filtered to separate the solid and liquid to obtain filter residue and filtrate. The filtrate can be used for desiliconization again.

[0036] Step 3: Place the obtained filter residue in an oven and dry it at 105°C to constant weight. Grind the dried vanadium residue with steel balls in a ball mill at a grinding speed of 80 rpm for 45 minutes. After grinding evenly, pass it through a 200-mesh sieve to obtain the desiliconized vanadium residue for subsequent vanadium extraction.

[0037] The content of vanadium in the desiliconized vanadium slag is 9.98wt% as V2O5, and the content of silicon in the vanadium slag is 0.43wt% as SiO2.

[0038] Example 3

[0039] A method for pretreatment and desiliconization of vanadium slag, comprising the following steps:

[0040] Step 1, take 200g of powdered vanadium slag through a 200 mesh sieve, the vanadium content in the vanadium slag is 11.31wt% as V2O5, and the silicon content in the vanadium slag is 8.53wt% as SiO2, slowly add 300mL of 60% sodium hydroxide solution to the vanadium slag, and stir and mix well to prepare a slurry;

[0041] Step 2: Pour the ore slurry into a glass container, heat it in a water bath and stir it for reaction, the water bath temperature is 85°C, the stirring speed is 180r / min, and the stirring reaction time is 150min; the fully reacted ore slurry is vacuum filtered to separate the solid and liquid to obtain filter residue and filtrate, and the filtrate can be used for desiliconization treatment again;

[0042] Step 3: Place the obtained filter residue in an oven and dry it at 105°C to constant weight. Grind the dried vanadium residue with steel balls in a ball mill at a grinding speed of 80 rpm for 45 minutes. After grinding evenly, pass it through a 200-mesh sieve to obtain the desiliconized vanadium residue for subsequent vanadium extraction.

[0043] The content of vanadium in the desiliconized vanadium slag is 10.78wt% as V2O5, and the content of silicon in the vanadium slag is 0.33wt% as SiO2.

[0044] Example 4

[0045] A method for pretreatment and desiliconization of vanadium slag, comprising the following steps:

[0046] Step 1: Take 200g of powdered vanadium slag through a 200-mesh sieve, the vanadium content of the vanadium slag being 9.63wt% as V2O5, and the silicon content of the vanadium slag being 7.11wt% as SiO2, slowly add 400mL of 65% sodium hydroxide solution to the vanadium slag, and stir and mix thoroughly to prepare a slurry.

[0047] Step 2: Pour the ore slurry into a glass container, heat it in a water bath and stir it for reaction, the water bath temperature is 90°C, the stirring speed is 160r / min, and the stirring reaction time is 180min; the fully reacted ore slurry is vacuum filtered to separate the solid and liquid to obtain filter residue and filtrate, and the filtrate can be used for desiliconization treatment again;

[0048] Step 3: Place the obtained filter residue in an oven and dry it at 105°C to constant weight. Grind the dried vanadium residue with steel balls in a ball mill at a grinding speed of 80 rpm for 45 minutes. After grinding evenly, pass it through a 200-mesh sieve to obtain the desiliconized vanadium residue for subsequent vanadium extraction.

[0049] The content of vanadium in the desiliconized vanadium slag is 9.51wt% as V2O5, and the content of silicon in the vanadium slag is 0.36wt% as SiO2.

[0050] Example 5

[0051] A method for pretreatment and desiliconization of vanadium slag, comprising the following steps:

[0052] Step 1, take 150g of powdered vanadium slag through a 200 mesh sieve, the vanadium content in the vanadium slag is 10.63wt% as V2O5, and the silicon content in the vanadium slag is 7.38wt% as SiO2, slowly add 300mL of 50% sodium hydroxide solution to the vanadium slag, and stir and mix well to prepare a slurry;

[0053] Step 2: introduce the ore slurry into a glass container, heat it in a water bath and stir it for reaction, the water bath temperature is 95°C, the stirring speed is 160r / min, and the stirring reaction time is 120min; the fully reacted ore slurry is vacuum filtered to separate the solid and liquid to obtain filter residue and filtrate, and the filtrate can be used for desiliconization treatment again;

[0054] Step 3: Place the obtained filter residue in an oven and dry it at 105°C to constant weight. Grind the dried vanadium slag evenly with steel balls in a ball mill and pass it through a 200-mesh sieve. Add 80°C hot water to the ball-milled filter residue for water immersion until the filter residue is completely immersed. Add 0.5L of 75mg / L ferric chloride solution and 0.5L of 75mg / L polyacrylamide solution during water immersion, and then ultrasonically treat it at 25kHz for 60min. After the treatment, separate the solid and liquid, and place the solid in an oven again to dry it to constant weight to obtain the desiliconized vanadium slag for subsequent vanadium extraction.

[0055] The content of vanadium in the desiliconized vanadium slag is 10.16wt% as V2O5, and the content of silicon in the vanadium slag is 0.18wt% as SiO2.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 5 is that 0.5 L of 150 mg / L ferric chloride solution and 0.5 L of 150 mg / L polyacrylamide solution are added thereto during water immersion, and the remaining steps are consistent with embodiment 6.

[0058] The content of vanadium in the desiliconized vanadium slag is 10.04wt% as V2O5, and the content of silicon in the vanadium slag is 0.11wt% as SiO2.

[0059] Comparative Example 1

[0060] The difference between this comparative example and Example 5 is that only ferric chloride solution is added after water immersion in step 3, and no polyacrylamide solution is added. The rest is consistent with Example 5.

[0061] The content of vanadium in the desiliconized vanadium slag is 10.14wt% as V2O5, and the content of silicon in the vanadium slag is 0.16wt% as SiO2.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 5 is that after the water soaking in step 3, only the polyacrylamide solution is added, and no ferric chloride solution is added. The rest is consistent with Example 5.

[0064] The content of vanadium in the desiliconized vanadium slag is 10.15wt% as V2O5, and the content of silicon in the vanadium slag is 0.15wt% as SiO2.

[0065] Comparative Example 3 This comparative example is desiliconized according to the method of patent CN102329954A, including:

[0066] Step 1, taking 150g of powdered converter vanadium slag after passing through a 200 mesh sieve (75μm) and mixing it with a sodium hydroxide solution to prepare a slurry; wherein the vanadium element in the vanadium slag is 10.63wt% in terms of V2O5, the silicon content in the vanadium slag is 7.38wt% in terms of SiO2, the concentration of the sodium hydroxide solution is 10mol / L, and 10mL of the sodium hydroxide solution is used for every 1g of the converter vanadium slag;

[0067] Step 2: Place the slurry obtained in step 1 in a leaching tank with electrodes and connect the power supply to pre-treat the slurry for leaching reaction; wherein the anode current density is 800 / m 2 , the leaching temperature is 80℃, and the leaching time is 2h;

[0068] Step 3: solid-liquid separation is performed on the slurry after the pretreatment leaching reaction in step 2 to obtain filter residue, and the obtained filter residue is dried at 105° C. for 3 hours. The dried filter residue is ground and evenly passed through a 100-mesh sieve (0.15 mm) to obtain pretreated converter vanadium slag for acid leaching of vanadium.

[0069] The content of vanadium in the desiliconized vanadium slag is 9.24wt% as V2O5, and the content of silicon in the vanadium slag is 2.08wt% as SiO2.

[0070] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for pretreatment and desiliconization of vanadium slag, characterized in that: The following steps are involved: Step 1, adding alkaline solution to the powdered vanadium slag passed through a 200-mesh sieve, stirring to make them fully contact, to prepare a slurry; Step 2: heating the slurry in a water bath, stirring the reaction, and then separating the solid and the liquid to obtain a filter residue; Step 3: drying the filter residue in an oven to constant weight; then grinding the filter residue evenly with a ball mill and passing it through a 200-mesh sieve to obtain desiliconized vanadium slag for subsequent vanadium extraction.

2. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step 1, the content of vanadium in the vanadium slag is 8wt% to 12wt% as V2O5, the content of silicon in the vanadium slag is 3% to 17% as SiO2, and the alkaline solution is a sodium hydroxide solution with a concentration of 50% to 80%.

3. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step 1, the solid-liquid ratio of the vanadium slag to the alkaline solution is 1-2:3-4.

4. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step 2, the water bath heating temperature is 60° C. to 90° C., the stirring speed is 150 r / min to 300 r / min, and the reaction time is 30 to 180 min.

5. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step 2, a multifunctional vacuum filter is used for filtration during solid-liquid separation.

6. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step 3, the oven temperature is set to 95°C to 105°C.

7. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: In the step three, a ball milling medium is added during ball milling, the ball milling medium is a steel ball, the ball milling speed is 60 to 120 rpm, and the ball milling time is 2 to 6 hours.

8. The method for pretreatment and desiliconization of vanadium slag according to claim 1, characterized in that: After the filter residue is ball-milled in step three, the filter residue is subjected to secondary desiliconization. The specific method is: the filter residue after ball milling is soaked in water, and then ferric chloride solution and polyacrylamide solution are added thereto, and then ultrasonic treatment is performed. After the treatment, the solid-liquid separation is performed, and the solid is placed in an oven again to dry to constant weight to obtain the desiliconized vanadium slag for subsequent vanadium extraction.

9. The method for pretreatment and desiliconization of vanadium slag according to claim 8, characterized in that: The water immersion temperature is 75-100° C. During the water immersion, it is ensured that the filter residue is completely immersed. The mass ratio of the filter residue, ferric chloride and polyacrylamide is 2:0.05-0.1:0.05-0.

1. The ultrasonic frequency is 25 kHz and the ultrasonic treatment is carried out for 30-90 minutes.

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