A method for flotation separation of refractory scheelite

Abstract

This invention belongs to the field of mineral processing technology, specifically relating to a method for the flotation separation of refractory scheelite. It employs polyglutamic acid as an inhibitor, which adsorbs onto the surface of calcite minerals, increasing the hydrophilicity of calcite minerals and thus selectively inhibiting calcite. Compared to traditional flotation processes, this method achieves good flotation separation of scheelite and calcite using only a very small amount of inhibitor and collector. Furthermore, polyglutamic acid is non-toxic, widely available, low-cost, and offers significant economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, specifically a method for flotation separation of refractory scheelite. Background Technology

[0002] Tungsten possesses excellent thermal conductivity, high hardness, and chemical stability. Due to its unique physical properties and superior physicochemical characteristics, it is widely used in high-tech product manufacturing and is an irreplaceable strategic metal for industrial development. China is known as the "Kingdom of Tungsten," with vast tungsten ore reserves. Among the many tungsten-bearing minerals, only wolframite and scheelite have significant mining and industrial value. However, with the increasing exploitation of tungsten resources, high-quality wolframite has been depleted. The comprehensive utilization of low-grade scheelite with complex associated components has become the mainstream approach. Scheelite, being a calcium-bearing mineral, often occurs in close association with calcium-bearing gangue minerals such as calcite in deposits. This makes the separation of scheelite from calcite a recognized technical challenge in mineral processing, prompting extensive research by domestic and international researchers on the separation of this type of ore.

[0003] Due to the generally low grade, uneven particle size distribution, and complex associated components of scheelite in my country, flotation is the most commonly used method for scheelite recovery. However, fatty acid collectors are typically added to improve the floatability of scheelite. Calcite and scheelite share the same Ca active sites and have very similar physicochemical properties. Furthermore, calcite exhibits excellent natural floatability, making the flotation separation of scheelite and calcite extremely difficult. Therefore, selectively reducing the floatability of calcite by adding depressants is crucial. However, existing depressants not only require large amounts of reagent and have poor calcite suppression effects, but also inhibit scheelite formation while suppressing calcite, resulting in low separation efficiency between scheelite and calcite, which is detrimental to the efficient utilization of scheelite resources. Summary of the Invention

[0004] To address the problems existing in the prior art, the main objective of this invention is to propose a flotation separation method for refractory scheelite, and to develop an inhibitor with high selectivity and excellent inhibition effect on calcite, thereby achieving efficient flotation separation of scheelite and calcite, which is of great significance for the efficient and comprehensive utilization of scheelite.

[0005] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0006] A method for flotation separation of refractory scheelite includes the following steps:

[0007] S1. Obtain slurry from difficult-to-process scheelite;

[0008] S2. Adjust the pH of the slurry and stir;

[0009] S3. Add polyglutamic acid to the slurry and stir for 3-5 minutes; the method of adding polyglutamic acid is as follows: the polyglutamic acid is prepared into a solution with a concentration of 0.1-1.0 wt%, and the solution volume is 10-60 mg / L;

[0010] S4. Continue adding sodium oleate and stirring. Finally, aeration flotation is used to obtain a foam product and a product in the tank. The foam product is scheelite, and the product in the tank is calcite.

[0011] As a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S1, the refractory scheelite raw material is ground finely, and the ground mineral raw material is added to the flotation cell of the flotation machine. Water is added to the flotation cell and stirred to obtain a uniform slurry.

[0012] As a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S1, the refractory scheelite raw material is ground to a particle size of 38-74 μm.

[0013] As a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S1, the solid-liquid ratio of the mineral raw material to water is 1:10 to 30 g / mL.

[0014] In a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S1, the rotation speed of the flotation machine is 1800-2000 r / min.

[0015] In a preferred embodiment of the flotation separation method for refractory scheelite described in this invention, the stirring time in step S2 is 3-5 minutes.

[0016] As a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S2, the pH value of the slurry is adjusted by a pH adjuster, wherein the pH adjuster is hydrochloric acid or sodium hydroxide.

[0017] In a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S2, the pH value of the slurry is adjusted to 7-11.

[0018] In a preferred embodiment of the flotation separation method for refractory scheelite described in this invention, the stirring time in step S4 is 3-5 minutes.

[0019] As a preferred embodiment of the flotation separation method for refractory scheelite according to the present invention, in step S4, sodium oleate is added in the following manner: sodium oleate is prepared into a solution with a concentration of 0.2-1.0 wt%, and the solution volume is 20-50 mg / L.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention proposes a method for the flotation separation of refractory scheelite, using polyglutamic acid as an inhibitor. Polyglutamic acid can adsorb onto the surface of calcite minerals, increasing the hydrophilicity of calcite minerals and thus selectively inhibiting calcite. Compared with traditional flotation processes, good flotation separation of scheelite and calcite can be achieved with very small amounts of inhibitors and collectors. At the same time, polyglutamic acid is non-toxic, widely available, low in cost, and has significant economic benefits. Detailed Implementation

[0022] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The main objective of this invention is to propose a flotation separation method for refractory scheelite, and to develop an inhibitor with high selectivity and excellent inhibition effect on calcite, so as to achieve efficient flotation separation of scheelite and calcite, which is of great significance for the efficient and comprehensive utilization of scheelite.

[0024] According to one aspect of the present invention, the present invention provides the following technical solution:

[0025] A method for flotation separation of refractory scheelite includes the following steps:

[0026] S1. Obtain slurry from difficult-to-process scheelite;

[0027] S2. Adjust the pH of the slurry and stir;

[0028] S3. Add polyglutamic acid to the slurry and stir for 3-5 minutes. The method of adding polyglutamic acid is as follows: prepare a solution with a concentration of 0.1-1.0 wt% and use a solution volume of 10-60 mg / L. If the concentration of polyglutamic acid is too high, the dissolution of polyglutamic acid will be more difficult, and the error caused by the dosing operation will be greater. If the concentration of polyglutamic acid is too low, the required volume of polyglutamic acid reagent will be too large, which can easily cause a sudden change in flotation concentration before and after the addition of reagent.

[0029] S4. Continue adding sodium oleate and stirring. Finally, aeration flotation is used to obtain a foam product and a product in the tank. The foam product is scheelite, and the product in the tank is calcite.

[0030] Preferably, in step S1, the refractory scheelite raw material is ground finely, and the ground mineral raw material is added to the flotation cell of the flotation machine. Water is added to the flotation cell and stirred to obtain a uniform slurry. More preferably, the refractory scheelite raw material is ground to a particle size of 38-74 μm; the solid-liquid ratio of the mineral raw material to water is 1:10-30 g / mL; and the rotation speed of the flotation machine is 1800-2000 r / min. Specifically, the solid-liquid ratio of the mineral raw material to water can be, for example, but not limited to, any one or a range between any two of 1:10 g / mL, 1:12 g / mL, 1:15 g / mL, 1:18 g / mL, 1:20 g / mL, 1:23 g / mL, 1:25 g / mL, 1:27 g / mL, and 1:30 g / mL; the rotational speed of the flotation machine can be, for example, but not limited to, any one or a range between any two of 1800 r / min, 1850 r / min, 1900 r / min, 1950 r / min, and 2000 r / min.

[0031] Preferably, in step S2, the pH value of the slurry is adjusted to 7-11 using a pH adjuster, which is hydrochloric acid or sodium hydroxide, and the stirring time is 3-5 minutes. Specifically, the pH value can be, for example, but not limited to, any one of 7, 8, 9, 10, 11 or any range between any two; the stirring time can be, for example, but not limited to, any one of 3 minutes, 3 minutes 30 seconds, 4 minutes, 4 minutes 30 seconds, 5 minutes or any range between any two.

[0032] Preferably, in step S3, the polyglutamic acid is added as follows: the polyglutamic acid is prepared into a solution with a concentration of 0.1-1.0 wt%, and the solution volume is 10-60 mg / L; specifically, the solution concentration can be, for example, but not limited to, any one or any two of 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%; the solution volume can be, for example, but not limited to, any one or any two of 10 mg / L, 15 mg / L, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L, 60 mg / L; the stirring time is, for example, but not limited to, any one or any two of 3 min, 3 min 30 s, 4 min, 4 min 30 s, 5 min.

[0033] Preferably, in step S4, sodium oleate is added by preparing a solution with a concentration of 0.2-1 wt% and using a solution volume of 20-50 mg / L.

[0034] The stirring time is 3 to 5 minutes. Specifically, the solution concentration can be, for example, but not limited to, any one or any two of 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, and 1.0 wt%; the solution volume can be, for example, but not limited to, any one or any two of 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, and 50 mg / L; and the stirring time can be, for example, but not limited to, any one or any two of 3 minutes, 3 minutes 30 seconds, 4 minutes, 4 minutes 30 seconds, and 5 minutes.

[0035] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0036] Example 1

[0037] A method for flotation separation of refractory scheelite includes the following steps:

[0038] S1. Obtain slurry from difficult-to-process scheelite;

[0039] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0040] S2. Add sodium hydroxide to adjust the pH of the slurry to 9 and stir for 3 minutes;

[0041] S3. Add 20 mg / L of 0.5 wt% polyglutamic acid to the slurry and stir for 5 min;

[0042] S4. Continue to add 20 mg / L of 0.5 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is performed to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and the in-tank product are dried, weighed and analyzed. The mineral processing results are shown in Table 1.

[0043] Table 1. Mineral processing results of Example 1

[0044]

[0045] Example 2

[0046] A method for flotation separation of refractory scheelite includes the following steps:

[0047] S1. Obtain slurry from difficult-to-process scheelite;

[0048] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0049] S2. Add hydrochloric acid to adjust the pH of the slurry to 8 and stir for 3 minutes;

[0050] S3. Add 20 mg / L of 1.0 wt% polyglutamic acid to the slurry and stir for 3 min;

[0051] S4. Continue to add 30 mg / L of 0.5 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is used to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and the in-tank product are dried, weighed and tested. The mineral processing results are shown in Table 2.

[0052] Table 2. Mineral processing results of Example 2

[0053]

[0054] Example 3

[0055] A method for flotation separation of refractory scheelite includes the following steps:

[0056] S1. Obtain slurry from difficult-to-process scheelite;

[0057] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0058] S2. Add sodium hydroxide to adjust the pH of the slurry to 10 and stir for 5 minutes;

[0059] S3. Add 50 mg / L of 0.5 wt% polyglutamic acid to the slurry and stir for 5 min;

[0060] S4. Continue to add 40 mg / L of 1.0 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is used to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and the in-tank product are dried, weighed and tested. The mineral processing results are shown in Table 3.

[0061] Table 3. Mineral processing results of Example 3

[0062]

[0063] Comparative Example 1

[0064] A method for flotation separation of refractory scheelite includes the following steps:

[0065] S1. Obtain slurry from difficult-to-process scheelite;

[0066] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0067] S2. Add hydrochloric acid to adjust the pH of the slurry to 8 and stir for 5 minutes;

[0068] S3. Add 150 mg / L of 0.5 wt% water glass to the slurry and stir for 5 min;

[0069] S4. Continue to add 80 mg / L of 0.5 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is used to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and the in-tank product are dried, weighed and tested. The mineral processing results are shown in Table 4.

[0070] Table 4 shows the mineral processing results of Comparative Example 1.

[0071]

[0072] Comparative Example 2

[0073] A method for flotation separation of refractory scheelite includes the following steps:

[0074] S1. Obtain slurry from difficult-to-process scheelite;

[0075] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0076] S2. Add sodium hydroxide to adjust the pH of the slurry to 9 and stir for 3 minutes;

[0077] S3. Add 90 mg / L of 0.3 wt% polyaspartic acid to the slurry and stir for 5 min;

[0078] S4. Continue to add 50 mg / L of 0.4 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is performed to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and in-tank product are dried, weighed and analyzed. The mineral processing results are shown in Table 5.

[0079] Table 4. Mineral processing results of Comparative Example 2

[0080]

[0081] Comparative Example 3

[0082] A method for flotation separation of refractory scheelite includes the following steps:

[0083] S1. Obtain slurry from difficult-to-process scheelite;

[0084] Grind the refractory scheelite to 38-74 μm, take 2g of the ground mineral raw material and add it to the flotation cell of the hanging flotation machine. Set the speed of the flotation machine to 1900 r / min, add 40mL of water and stir to obtain a uniform slurry.

[0085] S2. Add sodium hydroxide to adjust the pH of the slurry to 9 and stir for 3 minutes;

[0086] S3. Add 100 mg / L of 0.2 wt% carboxymethyl cellulose to the slurry and stir for 5 min;

[0087] S4. Continue to add 70 mg / L of 0.5 wt% sodium oleate and stir for 3 min. Finally, aeration flotation is used to obtain foam product and in-tank product. The foam product is scheelite and the in-tank product is calcite. The foam product and in-tank product are dried, weighed and tested. The mineral processing results are shown in Table 6.

[0088] Table 6. Mineral processing results of Comparative Example 3

[0089]

[0090] As can be seen from Examples 1-3 and Comparative Examples 1-3 of the present invention, the present invention uses polyglutamic acid as an inhibitor. Polyglutamic acid can be adsorbed on the surface of calcite minerals, increasing the hydrophilicity of calcite minerals, thereby producing a selective inhibitory effect on calcite. As can be seen from Comparative Example 2, even if polyaspartate ammonium, which is also an amino acid, is used, even if a larger amount is added, the effect of polyglutamic acid of the present invention cannot be obtained. Compared with the traditional flotation process, the present invention can achieve good flotation separation of scheelite and calcite with a very small amount of inhibitor and collector. At the same time, polyglutamic acid is non-toxic, widely available, low in cost, and has significant economic benefits.

[0091] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for flotation separation of refractory scheelite, characterized in that, Includes the following steps: S1. Grind the refractory scheelite raw material into a fine powder, add the finely ground mineral raw material into the flotation cell of the flotation machine, add water to the flotation cell and stir to obtain a uniform slurry; the solid-liquid ratio of the mineral raw material to water is 1:10~30 g / mL; S2. Adjust the pH of the slurry to 7-11 and stir; S3. Add polyglutamic acid to the slurry and stir for 3-5 minutes; the method of adding polyglutamic acid is as follows: the polyglutamic acid is prepared into a solution with a concentration of 0.1-1.0 wt%, and the solution volume is 20-50 mg / L; S4. Continue to add sodium oleate and stir. The sodium oleate is added in the following way: the sodium oleate is prepared into a solution with a concentration of 0.2~1.0wt%, and the solution volume is 20~40mg / L. Finally, aeration flotation is used to obtain foam product and in-tank product. The foam product is scheelite, and the in-tank product is calcite.

2. The method according to claim 1, characterized in that, In step S1, the refractory scheelite raw material is ground to a particle size of 38~74μm.

3. The method according to claim 1, characterized in that, In step S1, the rotational speed of the flotation machine is 1800~2000 r / min.

4. The method according to claim 1, characterized in that, In step S2, the stirring time is 3-5 minutes.

5. The method according to claim 1, characterized in that, In step S2, the pH value of the slurry is adjusted using a pH adjuster, which is hydrochloric acid or sodium hydroxide.

6. The method according to claim 1, characterized in that, In step S4, the stirring time is 3-5 minutes.

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