Method for improving double-reverse flotation froth of silicon-calcium collophanite

Abstract

The invention belongs to the technical field of phosphorite beneficiation, and particularly discloses a method for improving silicon-calcium collophanite double-reverse flotation froth, which comprises the following steps: adjusting the pH value of phosphorite pulp to be acidic by using oxalic acid, adding a magnesium removal collecting agent for reverse flotation magnesium removal to obtain magnesium-removed concentrate pulp, adding activated carbon into the magnesium-removed concentrate pulp, uniformly mixing, diluting the ore pulp, adjusting the pH value to be 6.5-8, and filtering to obtain the silicon-calcium collophanite double-reverse flotation froth. Adding the foam-inhibiting agent and uniformly mixing; and a cation collecting agent is added for dealumination and desiliconization reverse flotation, and ore pulp obtained after reverse flotation is subjected to solid-liquid separation, so that phosphate concentrate is obtained. According to the method provided by the invention, the pH is adjusted by adopting oxalic acid during reverse flotation magnesium removal, activated carbon is added into ore pulp after magnesium removal to mix an adsorption agent, and a foam inhibition agent is added; the physical and chemical properties of the surface of the foam can be changed, the half-life period of the foam is greatly shortened, and the beneficiation effect is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphate ore dressing, and relates to a froth flotation method for improving the double-reverse process of siliceous-calcium colloidal phosphate. Background Art

[0002] Collophanite is a collection of phosphate-based minerals containing associated minerals such as calcium, magnesium, aluminum and iron. Most collophanites cannot be directly used for chemical production and require mineral processing and impurity removal.

[0003] Double reverse flotation process is an effective means for the comprehensive development and utilization of medium and low-grade calcium silicate colloidal phosphate resources. It removes the aluminum silicate gangue by reverse flotation first and then removes the carbonate gangue by reverse flotation, or removes the carbonate gangue by reverse flotation first and then removes the silicate gangue by reverse flotation. In the double reverse flotation process, problems such as large flotation foam volume, high foam viscosity and poor fluidity are important factors restricting its continuous production operation. Cationic collectors have strong foaming properties for flotation of oxidized ores. The surface tension of amine cationic flotation foam is small, and a large amount of foam forms a dense and stable foam layer; the residual collector or Ca2+, Mg2+, PO3-4 and SO2-4 in the slurry leads to the deterioration of flotation foam and the decrease of collector selectivity; in addition, a part of ore slime will be produced during the grinding process. The fine-grained ore slime covers the surface of large-grained minerals, which not only reduces the selectivity of the collector, but also makes the flotation foam viscous.

[0004] CN112058503A discloses a double reverse flotation process for silico-calcium collophosphate, which is processed by reverse flotation demagnesiumization, reverse flotation demagnesium rough concentrate dehydration and slurry adjustment, reverse flotation desiliconization, etc., to finally obtain the concentrate. In the dealuminization stage of this process, a foaming cationic collector is used, and the foam has the characteristics of large foam volume, strong rigidity, and strong stability. In the reverse flotation demagnesiumization, phosphoric acid is used as a pH adjuster. The introduction of PO3-4 into the flotation system will aggravate the foam problem caused by cations.

[0005] CN 105562213A discloses a method for preparing sulfuric acid as a phosphate ore reverse flotation inhibitor, which comprises crushing the phosphate ore and using sulfuric acid for slurry preparation as a reverse flotation inhibitor. Although local materials can be used and the cost is low, the use of sulfuric acid as an inhibitor has a complex process flow, a large number of operations and dosing points, a large amount of sulfuric acid, and difficult operation and control, resulting in serious scaling of equipment pipelines.

[0006] CN 118477759A discloses an inhibitor for flotation quality improvement and impurity reduction of calcium-magnesium phosphate ore and its application, which uses organic acid and inorganic salt compounds as inhibitors and conventional fatty acid or amine agents as collectors to achieve effective flotation separation of phosphate ore. However, the residual collector or Ca2+, Mg2+, PO3-4 and SO2-4 in the ore pulp are not treated, resulting in relatively difficult control of flotation foam.

[0007] The cationic collectors commonly used in the market for flotation of oxidized ores have strong foaming properties. The surface tension of amine cationic flotation foam is small, and a large amount of foam forms a dense and stable foam layer, which is not suitable for direct application in production. Summary of the invention

[0008] The invention provides a method for improving the double reverse flotation foam of calcareous silicate collophanite. By optimizing the reagent system, the mutual influence of anionic and cationic collectors can be weakened, the influence of inevitable ions can be reduced, the foaming performance of the cationic collector can be inhibited, the surface tension of the foam can be increased, the fluidity of the cationic flotation foam can be improved, and the utilization rate of medium and low-grade calcareous silicate collophanite can be improved.

[0009] In order to achieve the above objectives, the present invention adopts the following technical solution: a method for improving the double reverse flotation foam of calcareous siliceous collophosphate, comprising the following steps: S1. The pH of the phosphate slurry is adjusted to be acidic by using oxalic acid, and a demagnesizing collector is added to perform reverse flotation demagnesization to obtain a demagnesized concentrate slurry; S2. Add activated carbon to the de-magnesium concentrate slurry and mix well. Then dilute the slurry, adjust the pH value to 6.5-8, and add the antifoaming agent and mix well. S3, adding cationic collector to S2 to carry out dealumination and desiliconization reverse flotation, and the slurry after reverse flotation is separated into solid and liquid to obtain phosphate concentrate.

[0010] Optionally, the P2O5 grade of the phosphate ore in the phosphate slurry is 20~30wt%, the Al2O3 grade is 2.0~7.0 wt%, and the MgO grade is 1.0~5.0 wt%.

[0011] Optionally, the concentration of the phosphate slurry in S1 is 30-35wt%, and the pH is adjusted to 4-5 using oxalic acid.

[0012] Optionally, the de-magnesium collector in S1 is XF-01, and the addition amount is 0.5~2.5kg / t.

[0013] Optionally, the amount of activated carbon added in S2 is 30-200 g / t; and the mixture is mixed for more than 10 minutes after addition.

[0014] Optionally, the water used for dilution in S2 is the water obtained after solid-liquid separation in S3, which is diluted to a pulp concentration of 15-30wt%; and the pH is adjusted with sodium carbonate and / or sodium bicarbonate.

[0015] Optionally, the antifoaming agent is one or more of polyether compounds, higher carbon alcohols or silicone oil defoaming agents; it is prepared into a 5-15% solution and the added amount is 30-300 g / t.

[0016] Optionally, the antifoaming agent satisfies at least one of the following conditions: the polyether compound is polyoxyethylene ether, polypropylene glycol and / or polyethylene glycol; the higher carbon alcohol is n-butanol, n-pentanol, isopentanol and isooctyl alcohol; the silicone oil is hydroxy silicone oil and / or polydimethylsiloxane.

[0017] Optionally, the ion collector is a mixture of quaternary ammonium and ether amine.

[0018] Optionally, the amount of cationic collector added is 100-500 g / t.

[0019] The present invention has the following beneficial effects: In the ore dressing stage of calcareous collophosphate ore, the present invention firstly performs reverse flotation to remove magnesium under acidic conditions, and specifically adopts oxalic acid to adjust the pH value. Compared with the traditional phosphoric acid or sulfuric acid, on the one hand, oxalic acid can be used to adjust the pH value of the pulp, and on the other hand, the inevitable ions such as Ca2+ and Mg2+ generated by the dissociation of C2O2-4 and grinding weaken its activation effect. In addition, it also avoids the introduction of PO3-4 and SO2- 4. The ore pulp obtained after reverse flotation and de-magnesiumization is mixed with activated carbon, which is used to remove the anion collector adsorbed on the surface of the mineral particles during the reverse flotation process to avoid the mutual influence of anions and cations during the reverse flotation process; and anti-foaming agents are added, among which higher carbon alcohols mainly play a defoaming role. Higher carbon alcohols with good dispersibility diffuse to the foam surface and react with the active functional groups on the foam surface to change the stability of the foam. Some molecules in the polyether molecules can replace the active molecules in the flotation foam film, change the properties of the film and make it fragile. Silicone oil derivatives can reduce the surface tension of the bubbles. Silicone oil has high wettability and is difficult to dissolve in water. It is easy to form a thin film on the foam, which can hinder the interaction between molecules and thus inhibit the formation of foam; then reverse flotation under neutral conditions is carried out to remove silicon and aluminum, which can improve the physical and chemical properties of the foam surface and greatly reduce its half-life, solving the problems of large flotation foam volume, high viscosity and poor fluidity in the traditional double reverse flotation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0022] Example 1 The double reverse flotation method of siliceous calcium collophosphate ore has the following specific operating steps: 1-1. After the phosphate ore is ground by water, phosphoric acid is used to adjust the pH value of the pulp to 4.8 and reverse flotation is carried out to remove magnesium. The collector for magnesium removal is XF-01, and the addition amount is 1.00kg / t. The Ca2+ content in the magnesium removal concentrate filtrate is 840 ppm, the Mg2+ content is 328 ppm, the PO3-4 content is 7881 ppm, and the SO2-4 content is 2110 ppm. Sodium carbonate is used to adjust the pH value to the range of 7-7.5, and then 280g / t of quaternary ammonium and ether amine (mass ratio 2:1) are added as collectors for reverse flotation to dealuminate and desiliconize. The flotation foam is fine and viscous, and the half-life exceeds 30 minutes.

[0023] 1-2. Under the same process conditions as 1-1, oxalic acid was used instead of phosphoric acid, and the Ca2+ content in the de-magnesiumized concentrate filtrate was reduced to 233 ppm, the Mg2+ content was 121 ppm, the PO3-4 content was 478 ppm, and the SO2-4 content was 80 ppm; the de-magnesiumized concentrate slurry was de-medicated with 50 g / t activated carbon powder, the slurry concentration was diluted to 20% with return water, and the pH value was adjusted to within the range of 7-7.5 with sodium carbonate; polypropylene glycol, isopentanol and hydroxy silicone oil were mixed in a mass ratio of 2:1:1 to prepare a 5% concentration solution, which was added to the slurry in an amount of 70 g / t; then quaternary ammonium and ether amine were added for reverse flotation dealumination (same as 1-1), the dealumination foam was significantly increased, and the foam half-life was reduced to 4 minutes.

[0024] Example 2 2-1. A certain calcareous colloidal phosphate mine adopts a double reverse flotation process of first flotation de-magnesiumization and then flotation de-siliconization and de-aluminization. Phosphoric acid is used as a pH adjuster in the de-magnesiumization stage, and the de-magnesiumization collector is XF-01, with an addition amount of 900g / t. The pH value of the de-magnesiumized concentrate filtrate obtained is adjusted to 7.5 with sodium carbonate, and etheramine is used for reverse flotation de-siliconization and de-aluminization. After 50 cycles of reverse flotation de-magnesiumization operation, the Ca2+ content in the return water is 621 ppm, the Mg2+ content is 870 ppm, the PO3-4 content is 6456 ppm, and the SO2-4 content is 2477 ppm.

[0025] 2-2, compared with 2-1, oxalic acid was used instead of phosphoric acid, and 60g / t activated carbon powder was added before desiliconization to remove the drug, and then sodium carbonate was used to adjust the pH value of the ore pulp to 7.5, and then etheramine was used for reverse flotation to remove silicon and aluminum. Compared with 2-1, the Ca2+ content in the return water dropped to 115 ppm, the Mg2+ content was 96 ppm, the PO3-4 content was 279 ppm, and the SO2-4 content was 101 ppm.

[0026] 2-3. Compared with 2-2, after adjusting the pH to 7.5, polyoxyethylene ether, polyethylene glycol, n-pentanol and dimethylsiloxane are mixed in a ratio of 2:1:1:1 to prepare a 5% antifoaming agent solution, which is added to the slurry for mixing at a dosage of 50 g / t; finally, etheramine is added for desiliconization and dealumination. After using the inhibitor, the amount of flotation foam is significantly reduced, the thickness of the flotation foam layer is reduced to 40% of the original, the foam half-life is reduced to 3 minutes, the fluidity of the desiliconization and dealumination flotation foam is significantly improved, and the defoaming and antifoaming effects of the mixed agent are fully exerted.

[0027] Example 3 The foaming test was carried out using a homemade cylindrical foaming device with a diameter of 10 cm and a height of 60 cm. The reagent mixing speed was 300 rpm and the inflation flow rate was 0.1 cubic meter per hour.

[0028] 3-1. Add 500 ml of deionized water to the foaming device, add etheramine at a speed of 300 rpm and stir thoroughly. The addition amount is 2 g / 100 L, and then blow for 2 minutes. The thickness of the foam layer is 39 cm and the foam half-life is 65 minutes.

[0029] 3-2. Under the same conditions as 3-1, after adding the same amount of etheramine, polyoxyethylene ether, isoamyl alcohol and hydroxy silicone oil are mixed in a ratio of 4:2:1 and added in an amount of 0.8 g / 100 L. Then, aerate for 2 minutes, the foam thickness is 17 cm, and the foam half-life is 7 minutes.

[0030] Example 4 The foaming test was carried out using a homemade cylindrical foaming device with a diameter of 10 cm and a height of 60 cm. The reagent mixing speed was 300 rpm and the inflation flow rate was 0.1 cubic meter per hour.

[0031] 4-1. Add 500 ml of a solution containing a quaternary ammonium salt into the foaming device for a foaming test. The dosage of the agent is 2 g / 100 L. Compressed air is introduced for 2 minutes. The thickness of the foam layer is 33 cm and the foam half-life is 47 minutes.

[0032] 4-2. Under the same conditions as 4-1, after adding the etheramine, a mixed antifoaming agent was added to suppress the flotation foam. The antifoaming agent was prepared by mixing polyoxyethylene ether, polyethylene glycol, n-pentanol and dimethylsiloxane in the ratio of 2:2:2:3. The dosage was 1.3 g / 100 L. The foam thickness was reduced to 12 cm and the foam half-life was reduced to 4 minutes.

[0033] Example 5 5-1. The double reverse flotation process of silico-calcium collophosphate ore is adopted, which is firstly desiliconization by flotation under neutral conditions and then demagnesiumization by reverse flotation under acidic conditions. Phosphoric acid is used to adjust the acidity and alkalinity of the ore pulp in the demagnesiumization stage. The cationic collector remaining in the desiliconization and dealuminization stages still has good foaming properties under acidic conditions. The demagnesiumization flotation foam is abundant, the foam properties are stable, the half-life is long, and the fluidity is poor; the desiliconization and dealuminization effects are poor.

[0034] 5-2. The process flow is changed to de-magnesium first and then de-siliconization. Oxalic acid is used to adjust the acidity and alkalinity of the de-magnesium operation pulp. 50g / t activated carbon powder is used to remove the medicine from the de-magnesium concentrate pulp. Sodium carbonate is used to adjust the pH value to 7. Polypropylene glycol, isoamyl alcohol and hydroxy silicone oil are mixed in a ratio of 2:1:1 to inhibit de-siliconization foam. The dosage is 60g / t. Under the same cationic collector dosage, the amount of de-siliconization flotation foam is significantly reduced, the flushing water can easily break the flotation foam, the foam half-life is significantly shortened, and the process has strong continuity.

[0035] The above embodiments describe the preferred implementation of the present invention, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for improving the double reverse flotation foam of siliceous-calcium collophanite, characterized in that: The following steps are involved: S1. The pH of the phosphate slurry is adjusted to be acidic by using oxalic acid, and a demagnesizing collector is added to perform reverse flotation demagnesization to obtain a demagnesized concentrate slurry; The magnesium-free concentrate slurry obtained in S2 and S1 is mixed with activated carbon, and then the slurry is diluted, and the pH value is adjusted to 6.5-8, and an antifoaming agent is added and mixed; S3, adding cationic collector to S2 to carry out dealumination and desiliconization reverse flotation, and the slurry after reverse flotation is separated into solid and liquid to obtain phosphate concentrate.

2. The method according to claim 1, characterized in that: The P2O5 grade of the phosphate ore in the phosphate slurry is 20~30wt%, the Al2O3 grade is 2.0~7.0 wt%, and the MgO grade is 1.0~5.0 wt%.

3. The method according to claim 1, characterized in that: The concentration of the phosphate slurry in S1 is 30-35wt%, and the pH is adjusted to 4-5 using oxalic acid.

4. The method according to claim 1, characterized in that: The de-magnesium collector in S1 is XF-01, and the addition amount is 0.5~2.5kg / t.

5. The method according to claim 1, characterized in that: The amount of activated carbon added in S2 is 30-200 g / t; after adding, the mixture is mixed for more than 10 minutes.

6. The method according to claim 1, characterized in that: The water used for dilution in S2 is the water obtained after solid-liquid separation of S3, which is diluted to a pulp concentration of 15-30 wt %; sodium carbonate and / or sodium bicarbonate are used to adjust the pH.

7. The method according to any one of claims 1 to 6, characterized in that: The antifoaming agent is one or more of polyether compounds, higher carbon alcohols or silicone oil defoaming agents; the antifoaming agent is then prepared into a 5-15% solution, and the usage amount is 30-300g / t.

8. The method according to claim 7, characterized in that The antifoaming agent meets at least one of the following conditions: the polyether compound is polyoxyethylene ether, polypropylene glycol and / or polyethylene glycol; the higher carbon alcohol is n-butanol, n-pentanol, isopentanol and isooctyl alcohol; the silicone oil is hydroxy silicone oil and / or polydimethylsiloxane.

9. The method according to claim 1, characterized in that: The cationic collector is one of quaternary ammonium and ether amine or a mixture thereof in a certain proportion.

10. The method according to claim 9, characterized in that: The amount of cationic collector added is 100~500g / t.

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