Preparation method of iron oxide ore flotation inhibitor

Abstract

The invention belongs to the technical field of iron ore flotation upgrading, and particularly relates to a preparation method of an iron oxide ore flotation depressing agent, which comprises the following specific steps: S1, taking a hydrophilic organic matter, adding the hydrophilic organic matter into a ferrous chloride / ferric chloride mixed solution according to the mass volume ratio of the hydrophilic organic matter to the ferrous chloride / ferric chloride mixed solution of 20-80 g / L, and stirring for 1-2 hours at the temperature of 50-90 DEG C; performing mechanical stirring reaction for 0.5 to 1.5 hours at the rotating speed of 200 to 600 r / S2, slowly adding an oil-in-water microemulsion into the solution obtained in the step S1, keeping the temperature at 80 DEG C, and stirring and reacting at the rotating speed of 300-500 r / min for 0.5-2 hours or more; and S3, a precipitant is dropwise added into the solution obtained in the step S2, a water bath constant-temperature stirring reaction is conducted, solid-liquid separation is conducted, the pH of collected solid matter is washed to be neutral through deionized water, and the strong-hydrophilicity iron oxide ore flotation inhibitor is obtained. According to the preparation method, the hydrophilicity of the inhibitor is enhanced, the problem that the flotation inhibitor is poor in adsorption selectivity on the mineral surface is solved, and hydrophilicity and selectivity are both considered.

Description

Technical Field

[0001] The invention belongs to the technical field of iron ore flotation and quality improvement, and in particular relates to a method for preparing an iron oxide ore flotation inhibitor. Background Art

[0002] Currently, flotation processes primarily utilize starch and dextrin to suppress iron minerals, with collectors used to float quartz and iron-containing silicate gangue minerals, thereby separating the iron minerals from the gangue minerals. Not only does the flotation process require the addition of large amounts of starch or its derivatives to suppress iron minerals, but it also has a weak inhibitory effect on fine-grained hematite, resulting in poor selectivity. CN119549285A discloses an inhibitor for reverse flotation of fine-grained hematite, 2-acrylamido-2-methylpropanesulfonic acid, and CN114669401A discloses a supramolecular inhibitor for reverse flotation of iron ore, an industrial alginate polymerization inhibitor. Both inhibitors require large dosages and suffer from the problem of being unable to balance hydrophilicity and selectivity. To obtain high-quality iron concentrate, particularly the flotation separation of iron oxide ore and iron-containing silicate minerals, efficient inhibitors are essential. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing an iron oxide ore flotation inhibitor, so as to solve the problems that the existing inhibitors require a large amount of inhibitors and cannot balance hydrophilicity and selectivity.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A method for preparing an iron oxide ore flotation inhibitor, comprising the following steps: S1: Take a hydrophilic organic compound and add it to a ferrous chloride / ferric chloride mixed solution. The mass volume ratio of the hydrophilic organic compound to the ferrous chloride / ferric chloride mixed solution is 20-80 g / L. The mixture is stirred mechanically at a temperature of 50-90 °C and a speed of 200-600 r / min for 0.5-1.5 h. S2: Slowly add the oil-in-water microemulsion to the solution obtained in step S1, maintain the temperature at 80°C, and stir at 300-500 r / min for more than 0.5-2 h; S3: adding a precipitant dropwise to the solution obtained in step S2, stirring the reaction in a water bath at a constant temperature, performing solid-liquid separation, and washing the collected solid matter with deionized water to a neutral pH value to obtain a strongly hydrophilic iron oxide ore flotation inhibitor.

[0005] The reactions in steps S1, S2 and S3 are all carried out under a nitrogen atmosphere.

[0006] Preferably, the hydrophilic organic matter in step S1 is a mixture of any one of maltitol and mannitol or both and succinic acid.

[0007] Preferably, when the hydrophilic organic matter in step S1 is succinic acid and maltitol or succinic acid and mannitol, the mass ratio of succinic acid to maltitol or mannitol is 1:3 to 1:10.

[0008] Preferably, when the hydrophilic organic matter in step S1 is a combination of succinic acid, maltitol and mannitol, the mass ratio of succinic acid: maltitol and mannitol is 1:3 to 1:10, and the mass ratio of maltitol: mannitol is 1:1: to 1:5.

[0009] Preferably, the ferrous chloride / ferric chloride mixed solution in step S1 is prepared from FeCl2 and FeCl3, Fe 2+ with Fe 3+ The molar ratio is 1:2, and the concentration of the ferrous chloride / ferric chloride mixed solution is 0.01-0.1 mol / L.

[0010] Preferably, the oil-in-water microemulsion in step S2 is composed of cetyltrimethylammonium bromide, n-hexanol and water, the mass ratio of cetyltrimethylammonium bromide:n-hexanol:water is 3:2:4, and the volume ratio of the oil-in-water microemulsion and the ferrous chloride / ferric chloride mixed solution is 1:1 to 1:3.

[0011] Preferably, in step S3, the precipitant is NH4OH with a mass fraction of 25%, and the volume ratio of NH4OH to the ferrous chloride / ferric chloride mixed solution is 1:5 to 2:5.

[0012] Preferably, the constant temperature reaction temperature in step S3 is 70-90° C., and the mechanical stirring is carried out at a speed of 200-600 r / min for 1-4 h.

[0013] The application of flotation depressants in the reverse flotation process of amine collectors is as follows: (1) The iron ore sample that has been ground to monomer dissociation is prepared into a pulp, and the pH value of the pulp is adjusted to 8-11; then, an inhibitor is added to the pulp and stirred for 3 minutes, an amine collector is added and stirred for 3 minutes, and finally, a frother is added and stirred for 1 minute, and then flotation is performed to obtain the iron concentrate product.

[0014] (2) The iron ore sample that was ground to monomer dissociation was prepared into a pulp, and the pH value of the pulp was adjusted to 8-11; then, an inhibitor was added to the pulp and stirred for 3 minutes, an amine collector was added and stirred for 3 minutes, and finally a frother was added and stirred for 1 minute. The roughing time was 3 minutes; the roughing concentrate (in-tank product) was subjected to a first concentration, with the concentration collector dodecylamine at a dosage of 20 mg / L and the flotation inhibitor A at a dosage of 100 mg / L. The concentration time was 3 minutes to obtain the final flotation concentrate (in-tank product).

[0015] The flotation depressant obtained by the method can be used in various amine collector reverse flotation processes, and its application is not limited to the above two processes.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The hydrophilicity of the inhibitor is enhanced by combining multiple hydrophilic functional groups such as succinic acid, maltitol, and mannitol in the hydrophilic organic matter. At the same time, the steric hindrance of the molecular structure of succinic acid, maltitol, and mannitol and the characteristics of strong active functional group screen are utilized to improve the problem of poor adsorption selectivity of flotation inhibitors on the mineral surface. The hydrophilicity and selectivity are both taken into consideration. Compared with traditional reverse flotation starch inhibitors, the dosage is small and the selectivity is good. (2) The nano-confinement effect of the water-in-oil microemulsion is used to control the nucleation and growth of the particles, ensuring that the prepared inhibitor has a small particle size, narrow distribution, good monodispersity, and a morphology that is approximately spherical, and the particles have good dispersion stability in the oil phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Flow chart of flotation test in Examples 1-4 and Comparative Example 1 of the present invention; Figure 2 This is a flow chart of the flotation test in Examples 5-7 of the present invention and Comparative Example 2. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0019] In the following Examples 1-4 and Comparative Example 1, the minerals used are magnetite, biotite and hornblende, and the grinding fineness is -0.074 mm, accounting for 80%. The chemical analysis thereof is as follows: Example 1

[0020] 1.0 g of succinic acid and 3.0 g of maltitol were weighed separately, added to 100 mL of a 0.05 mol / L ferrous chloride / ferric chloride mixed solution, and the mixture was stirred at 70°C and 400 r / min for 1.0 h. 100 mL of an oil-in-water microemulsion composed of cetyltrimethylammonium bromide, n-hexanol, and water in a mass ratio of cetyltrimethylammonium bromide:n-hexanol:water of 3:2:4 was slowly added to the reaction mixture. The mixture was stirred at 80°C and 300 r / min for 1.0 h. 25 mL of 25% NH4OH was added dropwise to the reaction mixture. The mixture was stirred at 90°C and 300 r / min for 2.0 h to prepare flotation depressant A.

[0021] Magnetite, biotite and hornblende minerals were added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide to adjust the slurry pH to 8.0, flotation depressant A at a dosage of 200 mg / L for 3 min, collector dodecylamine at a dosage of 60 mg / L for 3 min, and frother 2# oil at a dosage of 30 g / t for 1 min before flotation. The flotation time was 3 min. The effect of the depressant was evaluated by the recovery rate of the flotation foam product. Example 2

[0022] 1.0 g of succinic acid and 5.0 g of mannitol were weighed separately and added to 100 mL of a 0.1 mol / L ferrous chloride / ferric chloride mixed solution. The mixture was stirred mechanically at 90°C and 600 r / min for 1.5 h. 50 mL of an oil-in-water microemulsion composed of cetyltrimethylammonium bromide, n-hexanol, and water in a mass ratio of cetyltrimethylammonium bromide:n-hexanol:water of 3:2:4 was slowly added to the reaction mixture. The mixture was stirred at 80°C and 300 r / min for 1.0 h. 50 mL of 25% NH4OH was added dropwise to the reaction mixture. The mixture was stirred mechanically at 70°C and 600 r / min for 1.0 h to prepare flotation depressant B.

[0023] Magnetite, biotite and hornblende minerals were added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide to adjust the slurry pH to 8.0, flotation depressant B at a dosage of 200 mg / L for 3 min, collector dodecylamine at a dosage of 60 mg / L for 3 min, and frother 2# oil at a dosage of 30 g / t for 1 min before flotation. The flotation time was 3 min. The effect of the depressant was evaluated by the recovery rate of the flotation foam product. Example 3

[0024] 2.0 g of succinic acid, 2.0 g of maltitol, and 4.0 g of mannitol were weighed separately and added to 100 mL of a 0.01 mol / L ferrous chloride / ferric chloride mixed solution. The mixture was stirred mechanically at 50°C and 200 r / min for 1.5 h. 100 mL of an oil-in-water microemulsion composed of cetyltrimethylammonium bromide, n-hexanol, and water in a mass ratio of cetyltrimethylammonium bromide:n-hexanol:water of 3:2:4 was slowly added to the reaction mixture. The mixture was stirred at 80°C and 300 r / min for 1.0 h. 40 mL of 25% NH4OH was added dropwise to the reaction mixture. The mixture was stirred mechanically at 70°C and 200 r / min for 4.0 h to prepare flotation depressant C.

[0025] Magnetite, biotite and hornblende minerals were added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide to adjust the slurry pH to 8.0, flotation depressant C at a dosage of 200 mg / L for 3 min, collector dodecylamine at a dosage of 60 mg / L for 3 min, and frother 2# oil at a dosage of 30 g / t for 1 min before flotation. The flotation time was 3 min. The effect of the depressant was evaluated by the recovery rate of the flotation foam product. Example 4

[0026] 0.6 g of succinic acid, 0.9 g of maltitol, and 4.5 g of mannitol were weighed separately and added to 100 mL of a 0.1 mol / L ferrous chloride / ferric chloride mixed solution. The mixture was stirred mechanically at 90°C and 600 r / min for 0.5 h. 35 mL of an oil-in-water microemulsion composed of cetyltrimethylammonium bromide, n-hexanol, and water in a mass ratio of cetyltrimethylammonium bromide:n-hexanol:water of 3:2:4 was slowly added to the reaction mixture. The mixture was stirred at 80°C and 300 r / min for 0.5 h. 20 mL of 25% (mass fraction) NH4OH was added dropwise to the reaction mixture. The mixture was stirred mechanically at 90°C and 600 r / min for 1.0 h to prepare flotation depressant D.

[0027] Magnetite, biotite and hornblende minerals were added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide to adjust the slurry pH to 8.0, flotation depressant D at a dosage of 200 mg / L for 3 min, collector dodecylamine at a dosage of 60 mg / L for 3 min, and frother 2# oil at a dosage of 30 g / t for 1 min before flotation. The flotation time was 3 min. The effect of the depressant was evaluated by the recovery rate of the flotation foam product.

[0028] Comparative Example 1 Magnetite, biotite and hornblende minerals were added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide to adjust the slurry pH to 8.0, gelatinized starch at a dosage of 200 mg / L for 3 min, collector dodecylamine at a dosage of 60 mg / L for 3 min, and frother 2# oil at a dosage of 30 g / t for 1 min before flotation for 3 min. The effect of the inhibitor was evaluated by the recovery rate of the flotation foam product.

[0029] like Figure 1As shown, the flotation conditions of Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 are the same, but the flotation depressants used are different. The flotation results of Example 1, Example 2, Example 3, Example 4 and Comparative Example 1 are shown in Table 1.

[0030] Table 1 Flotation test results

[0031] As can be seen from Table 1, the flotation depressant prepared by the method of the present invention has a slightly smaller inhibitory effect on magnetite than the conventional starch depressant, but the inhibitory effect of the starch depressant on iron-containing silicate minerals is significantly higher than that of the flotation depressant prepared by the method of the present invention, indicating that the method of the present invention has a good selective inhibitory effect on magnetite.

[0032] The minerals used in Examples 5-7 and Comparative Example 2 are mixed ore consisting of magnetite, biotite, and hornblende in a mass ratio of 1:1:1, and the total iron grade is 32.79%. Example 5

[0033] The mixed ore was added to water to prepare a slurry with a mass concentration of 35%, and the following substances were added to the slurry in sequence: pH adjuster sodium hydroxide, the slurry pH was adjusted to 8.0, flotation depressant A was used at a dosage of 200 mg / L, the slurry was mixed for 3 minutes, collector dodecylamine was used at a dosage of 60 mg / L, the slurry was mixed for 3 minutes, and frother No. 2 oil was used at a dosage of 30 g / t, the slurry was mixed for 1 minute, and then flotation roughing was performed, the roughing time was 3 minutes; the roughing concentrate (in-tank product) was subjected to a primary concentration, the concentration collector dodecylamine was used at a dosage of 20 mg / L, the flotation depressant A was used at a dosage of 100 mg / L, the concentration time was 3 minutes, and the final flotation concentrate (in-tank product) was obtained. Example 6

[0034] The mixed ore was added to water to prepare a slurry with a mass concentration of 35%. The following substances were added to the slurry in sequence: pH adjuster sodium hydroxide, the slurry pH was adjusted to 8.0, flotation depressant B was added at a dosage of 200 mg / L, the slurry was mixed for 3 minutes, collector dodecylamine was added at a dosage of 60 mg / L, the slurry was mixed for 3 minutes, and frother No. 2 oil was added at a dosage of 30 g / t, the slurry was mixed for 1 minute, and then flotation roughing was performed for 3 minutes. The roughing concentrate (in-tank product) was subjected to primary concentration, the collector dodecylamine was added at a dosage of 20 mg / L, the flotation depressant B was added at a dosage of 100 mg / L, and the concentration time was 3 minutes to obtain the final flotation concentrate (in-tank product). Example 7

[0035] The mixed ore was added to water to prepare a slurry with a mass concentration of 35%, and the following substances were added to the slurry in sequence: pH adjuster sodium hydroxide, the slurry pH was adjusted to 8.0, flotation depressant C was added at a dosage of 200 mg / L, the slurry was mixed for 3 minutes, collector dodecylamine was added at a dosage of 60 mg / L, the slurry was mixed for 3 minutes, and frother No. 2 oil was added at a dosage of 30 g / t, the slurry was mixed for 1 minute, and then flotation roughing was performed, the roughing time was 3 minutes; the roughing concentrate (in-tank product) was subjected to a primary concentration, the concentration collector dodecylamine was added at a dosage of 20 mg / L, the flotation depressant C was added at a dosage of 100 mg / L, the concentration time was 3 minutes, and the final flotation concentrate (in-tank product) was obtained.

[0036] Comparative Example 2 The mixed ore was added to water to prepare a slurry with a mass concentration of 35%, and the following substances were added to the slurry in sequence: pH adjuster sodium hydroxide, the slurry pH was adjusted to 8.0, gelatinized starch was added at a dosage of 200 mg / L, the slurry was mixed for 3 minutes, the collector dodecylamine was added at a dosage of 60 mg / L, the slurry was mixed for 3 minutes, and frother No. 2 oil was 30 g / t, the slurry was mixed for 1 minute, and then flotation roughing was performed, the roughing time was 3 minutes; the roughing concentrate (in-tank product) was subjected to a primary concentration, the collector dodecylamine was added at a dosage of 20 mg / L, the gelatinized starch was added at a dosage of 100 mg / L, the concentration time was 3 minutes, and the final flotation concentrate (in-tank product) was obtained.

[0037] like Figure 2 As shown, Examples 5-7 and Comparative Example 2 used the same flotation conditions, except for the flotation depressants used: the flotation depressants prepared in Examples 1-3 and gelatinized starch, respectively. The flotation conditions differed slightly from those in Example 1. A two-stage flotation process separated and removed biotite and hornblende, improving the iron grade of the flotation concentrate. The flotation results for Examples 5, 6, 7, and Comparative Example 2 are shown in Table 2.

[0038] Table 2 Mixed ore flotation test results

[0039] As shown in Table 2, the concentrate grade and iron recovery rate obtained in Examples 5-7 are higher than those in Comparative Example 2, and the separation effect of magnetite and gangue minerals is better, indicating that the flotation depressant prepared by the method of the present invention has both hydrophilicity and selectivity, and can effectively and selectively depress magnetite; the combination of succinic acid, maltitol, and mannitol in the depressant can give full play to its own advantages, and the mutual synergy of carboxyl and hydroxyl groups can significantly improve the grade and recovery rate of iron concentrate.

Claims

1. A method for preparing an iron oxide ore flotation depressant, characterized in that: The specific steps are as follows: S1: Take a hydrophilic organic compound and add it to a ferrous chloride / ferric chloride mixed solution. The mass volume ratio of the hydrophilic organic compound to the ferrous chloride / ferric chloride mixed solution is 20-80 g / L. The mixture is stirred mechanically at a temperature of 50-90 °C and a speed of 200-600 r / min for 0.5-1.5 h. S2: Slowly add the oil-in-water microemulsion to the solution obtained in step S1, maintain the temperature at 80°C, and stir at 300-500 r / min for more than 0.5-2 h; S3: adding a precipitant dropwise to the solution obtained in step S2, stirring the reaction in a water bath at a constant temperature, performing solid-liquid separation, and washing the collected solid matter with deionized water to a neutral pH value to obtain a strongly hydrophilic iron oxide ore flotation inhibitor; The reactions in steps S1, S2 and S3 are all carried out under a nitrogen atmosphere.

2. The method for preparing an iron oxide ore flotation depressant according to claim 1, wherein: The hydrophilic organic matter in step S1 is a mixture of any one of maltitol and mannitol or both and succinic acid.

3. The method for preparing an iron oxide ore flotation depressant according to claim 2, wherein: When the hydrophilic organic matter in step S1 is succinic acid and maltitol or succinic acid and mannitol, the mass ratio of succinic acid to maltitol or mannitol is 1:3 to 1:

10.

4. The method for preparing an iron oxide ore flotation depressant according to claim 2, wherein: When the hydrophilic organic matter in step S1 is a combination of succinic acid, maltitol and mannitol, the sum of the mass of succinic acid:maltitol and mannitol is 1:3-1:10, and the mass of maltitol:mannitol is 1:1:-1:

5.

5. The method for preparing an iron oxide ore flotation depressant according to claim 1, wherein: In step S1, the ferrous chloride / ferric chloride mixed solution is prepared from FeCl2 and FeCl3. 2+ with Fe 3+ The molar ratio is 1:2, and the concentration of the ferrous chloride / ferric chloride mixed solution is 0.01-0.1 mol / L.

6. The method for preparing an iron oxide ore flotation depressant according to claim 1, wherein: In step S2, the oil-in-water microemulsion is composed of cetyltrimethylammonium bromide, n-hexanol and water, the mass ratio of cetyltrimethylammonium bromide:n-hexanol:water is 3:2:4, and the volume ratio of the oil-in-water microemulsion and the ferrous chloride / ferric chloride mixed solution is 1:1 to 1:

3.

7. The method for preparing an iron oxide ore flotation depressant according to claim 1, characterized in that: In step S3, the precipitant is NH4OH with a mass fraction of 25%, and the volume ratio of NH4OH to the ferrous chloride / ferric chloride mixed solution is 1:5 to 2:

5.

8. The method for preparing an iron oxide ore flotation depressant according to claim 1, wherein: In step S3, the constant temperature reaction temperature is 70-90° C., and the mechanical stirring is carried out at a speed of 200-600 r / min for 1-4 hours.

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