Application of alkalized tea saponin as talc inhibitor

Abstract

The invention discloses application of alkalized tea saponin as a talc inhibitor, and belongs to the technical field of mineral separation. The molecular structural formula of the alkalized tea saponin is shown in the specification, wherein R is a sugar body unit; m is a cation; the alkalized tea saponin has a selective inhibition effect on flotation of talc, and is particularly suitable for flotation separation of metal sulfide ore (such as molybdenite, chalcopyrite, galena and sphalerite) and talc.

Description

Technical Field

[0001] This invention relates to a novel use of alkalized tea saponin, particularly to an alkalized tea saponin used as a talc inhibitor for separating molybdenite and talc, belonging to the field of mineral processing technology. Background Technology

[0002] Tea saponin: Hunan has many tea trees, and the residue left after pressing tea seeds to extract tea oil is rich in tea saponin. At present, tea saponin has not been well utilized for high-value purposes and is only used in pesticides, feed and other fields.

[0003] Talc depressant: In the flotation of non-ferrous metal ores, such as copper, lead, zinc, and molybdenum sulfides, talc (layered magnesium silicate gangue) has good natural floatability and is easily mixed into sulfide ore concentrates. During smelting, talc and other magnesium silicate minerals tend to increase the viscosity of the molten metal in the smelting pool, leading to excessive adhesion of metallurgical products in the slag and resulting in losses during the metallurgical process. Simultaneously, magnesium oxide is a refractory material, which can increase heating costs in the metallurgical process. Therefore, efficient talc depressant control has always been a technical problem that needs to be solved in mineral processing.

[0004] Copper sulfide (molybdenum / lead / zinc) ores are important sources of metals, which are widely used in metallurgy, electronics, aerospace, and other fields. During the flotation of sulfide ores, easily floatable gangue minerals such as talc are often present. Due to its natural hydrophobicity and layered structure, talc readily floats with the sulfide ores during flotation, leading to a decrease in concentrate grade and difficulties in subsequent separation. Currently used talc depressants such as carboxymethyl cellulose and starch, while having some inhibitory effect, suffer from problems such as high dosage, poor selectivity, and environmental unfriendliness.

[0005] Tea saponin is a natural nonionic surfactant derived from tea seeds, possessing excellent dispersibility, foaming properties, and environmental friendliness. In existing research, tea saponin is primarily used as a foaming agent or cleaning agent, as seen in Chinese patents.

[0006] Application (Publication No.: CN119111538A) discloses a bactericide whose main active component is tea saponin. Similarly, Chinese patent application (Publication No.: CN120772020A) discloses a novel activator for sulfide ore beneficiation. Its preparation method involves first mixing basic copper carbonate and ammonium chloride to obtain a first mixture, then mixing the remaining components and heating and stirring to obtain a second mixture, and finally mixing the two evenly. This activator overcomes the shortcomings of traditional activators and has highly efficient activation performance, but its production cost is too high. The application of tea saponin as a selective inhibitor in mineral flotation, particularly in the separation of sulfide ores and talc, has not yet been systematically reported. Summary of the Invention

[0007] To address the technical problems of poor selectivity, large dosage, and significant environmental impact of existing talc inhibitors, the present invention aims to provide an application of alkalized tea saponin as a talc inhibitor. Using alkalized tea saponin for the flotation separation of molybdenite and talc can selectively inhibit talc flotation while having minimal impact on the floatability of sulfide ores, significantly improving the grade of sulfide ore concentrate. Furthermore, alkalized tea saponin is mainly extracted from tea seed cake, a byproduct of camellia oil extraction, resulting in relatively low cost and reducing usage costs.

[0008] To achieve the above-mentioned technical objectives, the present invention provides an application of alkalized tea saponin as a talc inhibitor.

[0009] As a preferred embodiment, the alkalized tea saponin has the following molecular structural formula:

[0010]

[0011] Where R is a glycosome unit and M is a cation.

[0012] As a preferred embodiment, the glycosome unit is composed of 2 to 4 monosaccharides linked by glycosidic bonds. R represents a glycosome unit, which is composed of 2 to 4 monosaccharides (such as glucose, arabinose, galactose, etc.) linked by glycosidic bonds.

[0013] The alkalized tea saponin of this invention is obtained by alkalizing tea saponin. The alkalization process deprotonates some of the less stable hydroxyl groups, generating hydrophilic groups such as oxygen anions, thereby causing a fundamental change in the molecular structure of tea saponin. The alkalized tea saponin contains highly hydrophobic triterpenoid saponins, as well as highly hydrophilic monosaccharides linked by glycosidic bonds to form natural glycosides and oxygen anions, etc., and has typical "amphiphilic molecules". This structure is the basis for its selective adsorption and inhibitory behavior.

[0014] The alkalized tea saponin of this invention can act as a talc inhibitor to achieve efficient separation of copper (molybdenum / lead / zinc) sulfide minerals from talc. The fundamental reason lies in the distinctly different interactions between the alkalized tea saponin molecules and the surfaces of the two minerals. A strong hydrophobic association and van der Waals forces exist between the highly hydrophobic triterpenoid saponin moiety and the hydrophobic surface of talc. This is the main driving force enabling the alkalized tea saponin molecules to spontaneously and firmly adsorb onto the talc surface. The alkalized tea saponin, with its triterpenoid saponin moiety "lying flat" or "anchored" on the hydrophobic surface of talc, extends its hydrophilic natural glycosides and oxygen anions into the water. This adsorption configuration produces a dual inhibitory effect. After alkalized tea saponins are directionally adsorbed on the surface of talc, their extended hydrophilic natural glycosides and oxygen anions act as a physical barrier on the talc surface, significantly increasing the energy barrier for talc particles to approach air bubbles, thus hindering their collision and adhesion. Furthermore, the hydrophilic sugar chains, rich in hydroxyl and carboxyl groups, can tightly bind with water molecules through hydrogen bonds, forming a strong and stable hydration film on the talc surface. This hydration film greatly enhances the hydrophilicity of the talc surface, making it difficult for it to break through the water film and adhere to air bubbles, thereby effectively inhibiting its floating in the slurry and exhibiting a strong inhibitory effect on talc flotation.

[0015] As a preferred option, alkalized tea saponin is used as a talc inhibitor for the flotation separation of talc and metal sulfide ores. Alkaline tea saponin exhibits selective adsorption on the talc surface, while showing almost no adsorption on metal sulfide ores, thus avoiding the collecting effect of metal sulfide ores collectors on talc and inhibiting talc flotation.

[0016] As a preferred embodiment, the metal sulfide ore includes at least one of chalcopyrite, molybdenite, galena, and sphalerite.

[0017] As a preferred method, the mixed minerals, including metal sulfide ore and talc, are slurried, and alkalized tea saponin is used as a talc inhibitor, while xanthate is used as a metal sulfide ore collector for flotation separation to obtain metal sulfide ore concentrate.

[0018] The alkalized tea saponin of the present invention has wide applicability and can be used in conjunction with conventional metal sulfide ore collectors to achieve the purpose of separating metal sulfide ore from talc by flotation.

[0019] As a preferred embodiment, the slurry is prepared to adjust the pH value of the slurry to a range of 7.0 to 10.0. This maintains the stable inhibitory properties of alkalized tea saponins within a slightly alkaline pH range. pH adjustment typically uses common alkaline compounds such as lime or sodium hydroxide.

[0020] As a preferred embodiment, the reagent regime for flotation separation is as follows: the concentration of alkalized tea saponin in the pulp is 20~200 mg / L; the concentration of xanthate in the pulp is 1.0×10⁻⁶ mg / L.-4 ~10×10 -4 mol / L; the concentration of the frother in the slurry is 1×10⁻⁶. -4 ~100×10 -4 mol / L. Alkalized tea saponin can achieve highly efficient inhibition of talc at relatively low dosages. Alkalized tea saponin can be used in conjunction with xanthate, a conventional collector for metal sulfide minerals, to achieve efficient separation of talc from metal sulfides.

[0021] The preparation method of alkalized tea saponin of the present invention adopts a one-step synthesis process: tea saponin and quicklime are added to water at a molar ratio of 1:(0.01~0.05), mixed, and stirred at room temperature for 1~5 minutes to obtain alkalized tea saponin; the specific reaction formula is as follows:

[0022]

[0023] When tea saponin is dissolved in water with a small amount of quicklime, the quicklime first reacts with the water to generate Ca(OH)₂, alkalizing the system. At this time, under weakly alkaline conditions, the hydroxyl groups in the tea saponin molecule undergo partial dehydrogenation and protonation, and the low concentration of Ca... 2+ It will form a weak coordination with the oxygen anion groups after the dissociation of tea saponin, but because Ca 2+ At low concentrations, no large amount of precipitate will form. The ester groups of tea saponin undergo only slight hydrolysis under weak alkalinity, and the overall molecular structure remains intact. The hydrophilic interaction between the dissociated hydroxyl groups and sugar groups is dominant. Therefore, tea saponin will first dissolve in the alkaline aqueous solution to achieve the purpose of alkalizing the tea saponin.

[0024] This invention describes the process of separating alkalized tea saponin from metal sulfide ores (using molybdenite as an example) and talc by flotation: 220 mL of deionized water and 2 g of molybdenite / talc mixed ore are prepared into a slurry, which is then stirred at 600 rpm for 1 min, a pH adjuster is added and stirred for 2 min, alkalized tea saponin is added and stirred for 3 min, then a molybdenite collector (xanthate) is added and stirred for 3 min, and finally a frother (methyl isobutyl methanol) is added and stirred for 1 min. After standing for 1 min, the mixture is transferred to a single bubble tube for aeration flotation for 3 min, and the concentrate and tailings are obtained by filtration, drying and weighing.

[0025] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0026] The alkalized tea saponin of the present invention is used as a talc inhibitor for the flotation separation of metal sulfide ores and talc. It has the advantages of good flotation separation effect, low inhibition concentration of alkalized tea saponin, and wide applicable pulp pH range, and has broad application prospects.

[0027] The alkalized tea saponin of the present invention can be simply synthesized from tea saponin, which is simple to operate, easy to obtain, low in cost, and environmentally friendly and safe. Attached Figure Description

[0028] Figure 1 The NMR spectrum of alkalized tea saponin TS is shown in the figure.

[0029] Figure 2 The infrared spectrum of alkalized tea saponin TS.

[0030] Figure 3 The image shows the ultraviolet spectrum of alkalized tea saponin TS.

[0031] Figure 4 A graph showing the relationship between the alkalization of tea saponins and the pH adaptability of molybdenite / talc (Guangdong).

[0032] Figure 5 A graph showing the relationship between the alkalization of tea saponins and the pH adaptability of molybdenite / talc (Henan). Detailed Implementation

[0033] The technical solutions of the present invention will be described in detail below through specific embodiments, but the following specific embodiments do not limit the scope of protection of the claims of the present invention.

[0034] Unless otherwise specified, all pharmaceutical agents used in the following examples are commercially available products. All concentrations or contents in the examples are by weight percentage.

[0035] The tea saponin of this invention is a commercially available tea saponin product: CAS: 8047-15-2. Commercially available tea saponins have poor water solubility at room temperature, which fails to meet the application requirements of flotation inhibitors.

[0036] Example 1

[0037] Dissolve 1.42 g of tea saponin in 50 ml of deionized water, then add 0.07 g of quicklime (CaO). Stir at 600 rpm for 3 min to obtain alkalized tea saponin (TS). The 1H NMR spectrum of the obtained product is shown below. Figure 1 Infrared spectrum Figure 2 The ultraviolet spectrum is shown below. Figure 3 .

[0038] 1H NMR spectrum Figure 1In the figure, the strong peak near 4.8 ppm is a characteristic peak of residual HDO (water) in heavy water solvent (proton signal of a small amount of H2O in D2O), which belongs to the solvent peak; the 1.0~2.0 ppm region: corresponding to the saturated alkyl hydrogen (-CH3 / -CH2-) on the triterpene core of tea saponin, which appears as multiple overlapping small peaks; the 3.0~5.0 ppm region: corresponding to the hydrogen (-CH-OH, -CH-O-) connected to the hydroxyl / ether bond on the glycosidic chain, as well as the hydroxyl-substituted hydrogen on the triterpene core; the small peak in the 3.4~5.0 ppm range in the figure is consistent with the chemical shift range of the glycosidic chain and hydroxyl hydrogen in tea saponin.

[0039] Infrared spectroscopy Figure 2 Middle, 3402cm -1 The peak at 2929 cm⁻¹ represents the stretching vibration of the hydroxyl group in TS. -1 The peak at 1467 cm⁻¹ represents the stretching vibration of the methyl / methylene group in TS. -1 The peak at this point represents the stretching vibration of the six-membered ring of TS. This figure shows the main functional groups of the tea saponin molecule: numerous hydroxyl groups (-OH) and complex alkyl structures (-CH3 / -CH2), and the spectral characteristics are in perfect agreement with the structure of tea saponin as a glycoside compound.

[0040] Ultraviolet absorption spectrum Figure 3 In the UV spectrum, a characteristic absorption peak appears at 286 nm, and there is no typical UV spectral behavior of long-wavelength absorption caused by obvious conjugated aromatic structure. Combining the position of the characteristic absorption peak and the spectral changes, the tea saponin at the detection site can be determined.

[0041] Example 2

[0042] Example 1: Study on the performance of the inhibitor prepared for single mineral flotation. 220 mL of deionized water and 2 g of molybdenite / talc (Guangdong) were used to prepare a slurry. The mixture was then stirred at 600 rpm for 1 min, and a pH adjuster (sodium hydroxide) was added to adjust the pH to 9. The mixture was stirred for 2 min, and then the inhibitor, alkalized tea saponin, was added to adjust the inhibitor to the set concentration. The mixture was stirred for 3 min, and then the collector, xanthate (SIBX), was added to adjust the concentration to 5.0 × 10⁻⁶. -4 The concentration of the frother in the slurry was 1.5 × 10⁻⁶ mol / L, and the frother concentration in the slurry was 1.5 × 10⁻⁶ mol / L. - 4 Stir for 1 min with mol / L solution. Let stand for 1 min, then transfer to a single bubble tube for aeration flotation for 3 min. Filter to obtain concentrate and tailings, then dry and weigh.

[0043] The inhibitor shown in Example 1 of this invention, when used in conjunction with xanthate, exhibits good inhibitory activity against talc (Guangdong) and weak inhibitory activity against molybdenite. At an inhibitor concentration of 50 mg / L and pH=9, the inhibitor in Example 1 achieved a flotation recovery rate of 44.2% for talc (Guangdong) and a flotation recovery rate of 67.26% for molybdenite. See details below. Figure 4 .

[0044] from Figure 4 As shown, the inhibitor shown in Example 1 of the present invention maintains a stable inhibitory effect on sulfide minerals and talc (Guangdong) as pH increases. This demonstrates that the alkalized tea saponin flotation inhibitor shown in Example 1 has good adaptability.

[0045] Example 3

[0046] Example 1: Study on the performance of the inhibitor prepared for single mineral flotation. 220 mL of deionized water and 2 g of molybdenite / talc (Henan) were used to prepare a slurry. The mixture was then stirred at 600 rpm for 1 min, and a pH adjuster (sodium hydroxide) was added to adjust the pH to 9. The mixture was stirred for 2 min, and then the inhibitor, alkalized tea saponin, was added to adjust the inhibitor to the set concentration. The mixture was stirred for 3 min, and then the collector, xanthate (SIBX), was added to adjust the concentration to 5.0 × 10⁻⁶. -4 The concentration of the frother in the slurry was 1.5 × 10⁻⁶ mol / L, and the frother concentration in the slurry was 1.5 × 10⁻⁶ mol / L. -4 Stir for 1 min with mol / L solution. Let stand for 1 min, then transfer to a single bubble tube for aeration flotation for 3 min. Filter to obtain concentrate and tailings, then dry and weigh.

[0047] The inhibitor shown in Example 1 of this invention has good inhibitory ability against talc (Henan) and weak inhibitory ability against molybdenite; under the conditions of alkalized tea saponin concentration of 25 mg / L and pH=9, the flotation recovery rate of the inhibitor in Example 1 for talc (Henan) is 38.92%, and the flotation recovery rate for molybdenite is 67.26%. See details below. Figure 4 .

[0048] from Figure 4 , 5 As shown, the inhibitor presented in Example 1 of this invention, when used in conjunction with the collector xanthate, maintains good inhibitory activity against both talc (Henan) and talc (Guangdong). Therefore, the flotation inhibitor prepared in Example 1 exhibits good selectivity and wide applicability.

Claims

1. An application of alkalized tea saponin, characterized in that: Application as a talc inhibitor.

2. The application of an alkalized tea saponin according to claim 1, characterized in that: The alkalized tea saponin has the following molecular structural formula: ； Where R is a glycosome unit and M is a cation.

3. The application of an alkalized tea saponin according to claim 2, characterized in that: The glycosome unit is composed of 2 to 4 monosaccharides linked by glycosidic bonds.

4. The application of an alkalized tea saponin according to any one of claims 1 to 3, characterized in that: It is used as a talc inhibitor for the flotation separation of talc and metal sulfide ores.

5. The application of an alkalized tea saponin according to claim 4, characterized in that: The metal sulfide minerals include at least one of chalcopyrite, molybdenite, galena, and sphalerite.

6. The application of an alkalized tea saponin according to any one of claims 1 to 3 and 5, characterized in that: The mixed minerals, including metal sulfide ore and talc, are slurried, and alkalized tea saponin is used as a talc inhibitor. Xanthate is used as a metal sulfide ore collector for flotation separation to obtain metal sulfide ore concentrate.

7. The application of an alkalized tea saponin according to claim 6, characterized in that: The slurry preparation is to adjust the pH value of the slurry to the range of 7.0 to 10.

0.

8. The application of an alkalized tea saponin according to claim 6, characterized in that: The reagent system for flotation separation is as follows: The concentration of alkalized tea saponin in the pulp is 20-200 mg / L; The concentration of xanthate in the pulp was 1×10 -4 ~10×10 -4 mol / L; The concentration of the frother in the slurry is 1×10 -4 ~100×10 -4 mol / L.

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