A method for selectively floating separation of zircon and kyanite in a beach placer

Abstract

The application provides a method for selectively floating and separating zircon and kyanite in beach placer, and relates to the technical field of resource recycling. The method comprises the following steps: firstly, slurry is formed by adjusting beach placer ore, and a pH adjusting agent is added into the slurry to adjust the pH of the slurry to 8-10; then, an inhibitor, an anionic collector and a foaming agent are sequentially added into the slurry, and the slurry is floated, so that the kyanite enters the foam product, and the zircon remains in the tank product, thereby realizing the reverse flotation separation of the zircon and the kyanite. The method has the advantages of simple process flow, stable reagent system and high separation efficiency, and is suitable for the efficient separation and comprehensive utilization of resources of the zircon and the kyanite in the beach placer.

Description

Technical Field

[0001] This invention relates to the field of resource recycling technology, and in particular to a selective flotation separation method for zircon and kyanite in coastal placer deposits. Background Technology

[0002] Zircon (ZrSiO4) is an important industrial mineral raw material with wide applications in ceramics, refractories, casting, and nuclear industries. Kyanite (Al2SiO5) is an important raw material for high-performance refractories.

[0003] In coastal placer deposits, zircon and kyanite often coexist. Their close association and widespread coexistence in coastal placer deposits pose significant challenges to their individual recovery. Because the two minerals have similar densities, traditional gravity separation processes rely on density differences for separation. However, the density difference between zircon (approximately 4.7 g / cm³) and kyanite (approximately 3.6 g / cm³) is relatively limited, making effective separation difficult with conventional gravity separation processes. Typically, only preliminary enrichment is achieved, resulting in high impurity content in the concentrate, which fails to meet the high-purity raw material requirements of industrial applications. Current research on kyanite beneficiation mainly focuses on its separation from gangue minerals such as quartz, feldspar, and mica, while research on the flotation separation of kyanite and zircon is limited.

[0004] Patent application CN 102744144 A discloses a beneficiation method for preparing kyanite ore, which uses a combination of magnetic separation-gravity separation-flotation-acid leaching to prepare kyanite concentrate. The process is complex, and it is only for kyanite ore, without mentioning a method for separating kyanite that is associated with zircon.

[0005] Therefore, it is of great significance to develop a new method that can achieve efficient separation of zircon and kyanite. Summary of the Invention

[0006] To address the technical problem of the similar density of zircon and kyanite in coastal placer deposits, making effective gravity separation difficult, this invention provides a selective flotation separation method for zircon and kyanite in coastal placer deposits. By adjusting the pulp pH to a slightly alkaline condition and adding inhibitors, fatty acid anionic collectors, and frothers, the collectors preferentially adsorb onto the surface of kyanite, causing kyanite to enter the froth product while zircon remains in the product, thus achieving efficient separation of the two minerals. The technical solution is as follows: A selective flotation separation method for zircon and kyanite in coastal placer deposits, the method comprising: S1. Prepare the raw coastal sand ore into a slurry; S2. Add pH adjuster to the slurry to adjust the pH of the slurry to 8-10; S3. Add inhibitor, anionic collector and frother to the slurry in sequence to perform flotation on the slurry. Kyanite enters the froth product and zircon remains in the product in the tank, realizing the reverse flotation separation of zircon and kyanite.

[0007] The S1 coastal sand deposit has a ZrO2 grade of 20-40%, an Al2O3 grade of 15-30%, and a particle size of 0.074-0.180 mm.

[0008] The slurry concentration in S1 is 20%~40%.

[0009] The pH adjuster in S2 is one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, calcium oxide, and calcium hydroxide, and the total amount of pH adjuster is 0.6~3 Kg / t.

[0010] The inhibitor in S3 is one or more of water glass, sodium fluorosilicate, and sodium hexametaphosphate, and the total amount of inhibitor is 0.05~0.15Kg / t.

[0011] The anionic collector in S3 is a fatty acid collector, including one or more of sodium oleate, oleic acid, linoleic acid, linolenic acid, lauric acid, and palmitic acid, with a total amount of collector of 0.6~4 kg / t.

[0012] The foaming agent in S3 is one or more of sodium di(2-ethylhexyl) succinate sulfonate, sodium diisooctyl succinate sulfonate, and No. 2 oil, and the total amount of foaming agent is 0.2 to 2 kg / t.

[0013] The flotation process in S3 includes at least one roughing stage, with the tailings from the previous roughing stage serving as the feed for the next roughing stage, and all roughing concentrates combined to form the final concentrate.

[0014] In S3, the amount of reagent used in the subsequent roughing process is half that used in the previous roughing process.

[0015] After adding the pH adjuster in step S2, stir for 3-5 minutes. After adding the inhibitor in step S3, stir for 3-5 minutes. Then, add the collector and stir for 4-6 minutes. After adding the frother and stirring for 1-3 minutes, float the mixture. The flotation time is 3-8 minutes.

[0016] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: Compared with current gravity separation processes, the flotation process provided by this invention can not only obtain higher concentrate grades, but also achieve a comprehensive improvement in the recovery rate of useful minerals, and has a wide range of applicable particle sizes.

[0017] This invention uses sodium oleate as a kyanite collector, which has good selectivity for kyanite but almost no selectivity for zircon. It is effective in reducing the zircon grade in kyanite concentrate and can provide high-quality raw materials for subsequent kyanite production and application.

[0018] Compared with traditional gravity separation processes, the flotation process of this invention has the advantages of simple process, low energy consumption and stable operation.

[0019] In summary, the process of this invention is simple, the reagent system is stable, and the separation efficiency is high. It is suitable for the efficient separation and comprehensive utilization of zircon and kyanite in coastal placer deposits and has good prospects for industrial application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a selective flotation separation method for zircon and kyanite in coastal placer deposits provided by an embodiment of the present invention; Figure 2 is a stereomicroscope image of kyanite concentrate, zircon, and actual ore after flotation separation of a coastal placer provided in an embodiment of the present invention, wherein (a) is the actual ore, (b) is the kyanite ore after flotation separation, and (c) is zircon. Figure 3 This is an infrared spectrum of a pharmaceutical preparation found in coastal sand deposits, provided in an embodiment of the present invention. Figure 4 This is an infrared spectrum of kyanite in a coastal placer deposit before and after the application of a pharmaceutical agent, provided in an embodiment of the present invention. Figure 5 This is an infrared spectrum of zircon in a coastal placer deposit before and after the application of a reagent, provided in an embodiment of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0023] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0024] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0025] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0026] This invention provides a method for the selective flotation separation of zircon and kyanite in coastal placer deposits. For example... Figure 1 The flowchart shown illustrates a selective flotation separation method for zircon and kyanite in coastal placer deposits. This method may include the following steps: S1. Prepare the raw coastal sand ore into a slurry; S2. Add pH adjuster to the slurry to adjust the pH of the slurry to 8-10; S3. Add inhibitor, anionic collector and frother to the slurry in sequence to perform flotation on the slurry. Kyanite enters the froth product and zircon remains in the product in the tank, realizing the reverse flotation separation of zircon and kyanite.

[0027] The following description, in conjunction with specific embodiments, illustrates this point.

[0028] Example 1

[0029] A coastal placer deposit has a raw ore grade of 31.19% ZrO2 and 22.68% Al2O3. The main minerals in the slurry are kyanite and zircon, with small amounts of rutile and quartz. First, 0.6 kg / t of sodium carbonate is added to adjust the slurry pH to 8, and the mixture is stirred for 3 minutes. Then, 0.6 kg / t of water glass is added, and the mixture is stirred for 3 minutes. Next, 1 kg / t of sodium oleate collector is added, and the mixture is stirred for 5 minutes. Then, 0.3 kg / t of No. 2 oil is added, and the mixture is stirred for 2 minutes. The mixture is then subjected to ambient temperature flotation, undergoing a four-stage roughing process (each roughing concentrate is combined into the final concentrate). The resulting flotation froth is kyanite, and the slurry in the tank is zircon.

[0030] After flotation, the product is filtered, dried, weighed, and chemically analyzed.

[0031] The results showed that the Al2O3 grade in the flotation froth increased to 57.20%, with a recovery rate of 91.88%; the ZrO2 grade in the product remaining in the tank reached 49.68%, with a recovery rate of 99.01%. This example successfully verified the good selectivity of sodium oleate for kyanite and effectively reduced the zircon grade in kyanite concentrate.

[0032] Example 2

[0033] A coastal sandy ore with the same properties as in Example 1 was used, with a ZrO2 grade of 31.19% and an Al2O3 grade of 22.68%. First, sodium hydroxide was added as a modifier at a dosage of 1.5 kg / t to adjust the pH of the slurry to 9, and the mixture was stirred for 3 minutes. Then, 0.6 kg / t of water glass was added, and the mixture was stirred for 3 minutes. Subsequently, linoleic acid was added as an anionic collector at a dosage of 1 kg / t to adjust the slurry, and the mixture was stirred for 5 minutes. Next, No. 2 oil was added at a dosage of 0.3 kg / t, and the mixture was stirred for 2 minutes. Then, room temperature flotation was performed. After four roughing processes, the flotation froth was obtained as kyanite, and the slurry in the tank was obtained as zircon.

[0034] The test results after flotation showed that the Al2O3 grade in the flotation foam increased to 55.62%, with a recovery rate of 89.35%; the ZrO2 grade in the product remaining in the tank reached 48.91%, with a recovery rate of 97.25%.

[0035] This example demonstrates that, under pH 9 conditions, changing the type of fatty acid can still achieve effective separation of the two minerals.

[0036] Example 3

[0037] A coastal sandy ore with the same properties as in Example 1 was used, with a ZrO2 grade of 31.19% and an Al2O3 grade of 22.68%. First, calcium oxide was added to adjust the slurry pH to 8 at a rate of 2 kg / t, and the mixture was stirred for 3 minutes. Then, 0.6 kg / t of water glass was added and stirred for 3 minutes. Next, a complex fatty acid collector (mainly oleic acid and palmitic acid) was added at a rate of 2 kg / t and stirred for 5 minutes. Subsequently, No. 2 oil was added as a frother at a rate of 0.3 kg / t and stirred for 2 minutes. Finally, room temperature flotation was carried out. After four roughing separation processes, the flotation froth was obtained as kyanite, and the slurry in the tank was obtained as zircon.

[0038] The test results after flotation showed that the Al2O3 grade in the flotation foam increased to 54.37%, with a recovery rate of 88.42%; the ZrO2 grade in the product remaining in the tank reached 49.52%, with a recovery rate of 96.83%.

[0039] This embodiment verifies that even with a high amount of collector, the process still exhibits excellent sorting performance and strong system stability.

[0040] Comparative Example 1

[0041] The same coastal placer deposit with the same properties as in Example 1 was separated using a traditional shaking table separation process. The raw ore had a ZrO2 grade of 31.19% and an Al2O3 grade of 22.68%. The test results showed that the ZrO2 grade in the gravity concentrate was 45.35% with a recovery rate of 85.42%, and the Al2O3 grade in the tailings was 40.23% with a recovery rate of 81.67%. A large amount of kyanite and zircon could not be effectively liberated.

[0042] Compared to Example 1, the conventional gravity separation process in Comparative Example 1 only achieved preliminary enrichment, resulting in a higher impurity content in the concentrate product. This demonstrates that the flotation process of the present invention, which uses a pH adjuster to a weakly alkaline state and is combined with a fatty acid collector, not only has a shorter process and higher separation efficiency, but also significantly improves the concentrate grade and the recovery rate of useful minerals.

[0043] The selection results of Examples 1-3 and Comparative Example 1 are shown in Table 1.

[0044] Table 1. Test Results

[0045] according to Figure 2 Zircon particles are mainly irregularly shaped, mostly pink, yellow, or colorless and transparent, with a clean surface and a typical vitreous luster. Kyanite particles are mainly tabular and elongated columnar crystals, predominantly pale blue, some nearly colorless, and a few yellow, transparent to translucent, with a distinct vitreous luster. In actual mineral samples, the mineral composition is quite complex, with kyanite and zircon closely associated, making effective separation difficult. After flotation treatment according to this invention, kyanite particles are significantly enriched, and the zircon content is significantly reduced, indicating that this invention can achieve highly efficient and selective separation of kyanite and zircon.

[0046] In the flotation system of this invention, fatty acid anionic collectors exist in the form of carboxylate ions under weakly alkaline conditions, as shown in the Fourier transform infrared (FTIR) spectrum. Figure 3 , Figure 4 and Figure 5 Analysis showed that after the collector acted on the kyanite surface, the symmetric stretching vibration peak of the carboxylate group decreased from 1450 cm⁻¹. - ¹Shifted to 1464 cm - ¹(Offset 14 cm) - ¹), asymmetric stretching vibration peak (1562 cm⁻¹) - ¹) The disappearance indicates that the carboxylate groups of the collector underwent chemical coordination adsorption with the Al active sites on the kyanite surface; sodium oleate –CH2- and –COO groups can still be observed in kyanite after water glass treatment. -The characteristic peaks showed only a slight decrease in intensity, indicating that sodium oleate can still be effectively adsorbed onto the kyanite surface. Since no obvious characteristic peaks of water glass were detected, it suggests that the adsorption of water glass on the kyanite surface is weak, and its impact on the adsorption of sodium oleate and the hydrophobicity of kyanite is minimal.

[0047] In contrast, sodium oleate can adsorb onto the zircon surface, but the adsorption amount is small. After pretreatment with water glass, the characteristic peak intensity of sodium oleate is significantly weakened, while the OH characteristic peak of water glass appears, indicating that water glass preferentially adsorbs onto the zircon surface and occupies active sites, effectively inhibiting the adsorption of sodium oleate. Therefore, water glass can enhance the hydrophilicity of the zircon surface, achieving selective inhibition of zircon adsorption.

[0048] Based on the difference in surface chemical properties of these minerals, kyanite preferentially adheres to bubbles and enters the foam product, while zircon remains in the product inside the tank, thus achieving selective separation of the two minerals.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A selective flotation separation method for zircon and kyanite in coastal placer deposits, characterized in that, The method includes: S1. Prepare the raw coastal sand ore into a slurry; S2. Add pH adjuster to the slurry to adjust the pH of the slurry to 8-10; S3. Add inhibitor, anionic collector and frother to the slurry in sequence to perform flotation on the slurry. Kyanite enters the froth product and zircon remains in the product in the tank, realizing the reverse flotation separation of zircon and kyanite.

2. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The S1 coastal sand deposit has a ZrO2 grade of 20-40%, an Al2O3 grade of 15-30%, and a particle size of 0.074-0.180 mm.

3. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The slurry concentration in S1 is 20%~40%.

4. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The pH adjuster in S2 is one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, calcium oxide, and calcium hydroxide, and the total amount of pH adjuster is 0.6~3 Kg / t.

5. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The inhibitor in S3 is one or more of water glass, sodium fluorosilicate, and sodium hexametaphosphate, and the total amount of inhibitor is 0.05~0.15Kg / t.

6. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The anionic collector in S3 is a fatty acid collector, including one or more of sodium oleate, oleic acid, linoleic acid, linolenic acid, lauric acid, and palmitic acid, with a total amount of collector used of 0.6~4 kg / t.

7. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The foaming agent in S3 is one or more of sodium di(2-ethylhexyl) succinate sulfonate, sodium diisooctyl succinate sulfonate, and No. 2 oil, and the total amount of foaming agent is 0.2~2 Kg / t.

8. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, The flotation process in S3 includes at least one roughing stage, with the tailings from the previous roughing stage serving as the feed for the next roughing stage, and all roughing concentrates combined to form the final concentrate.

9. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 8, characterized in that, In S3, the amount of reagent used in the subsequent roughing process is half that used in the previous roughing process.

10. The selective flotation separation method for zircon and kyanite in coastal placer deposits according to claim 1, characterized in that, After adding the pH adjuster in step S2, stir for 3-5 minutes. After adding the inhibitor in step S3, stir for 3-5 minutes. Then add the collector and stir for 4-6 minutes. After adding the frother and stirring for 1-3 minutes, float the mixture. The flotation time is 3-8 minutes.

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