A soft potassium magnesium alum flotation composite reagent, its preparation method and uses

Abstract

This invention relates to a highly stable soft potassium magnesium alum flotation composite reagent, belonging to the field of mineral processing flotation reagent technology. The composition, by mass ratio, is as follows: 15-25 parts dodecylbenzenesulfonic acid triethanolamine salt as the main collector, 3-8 parts sodium fatty acid methyl ester sulfonate as the auxiliary collector, 8-12 parts polyoxyethylene sorbitan fatty acid ester as the stabilizer, 3-5 parts methyl isobutyl methanol as the frother, 1-3 parts fatty alcohol polyoxyethylene ether as the foam regulator, 0.5-1.5 parts sodium polyphosphate as the dispersant, and 8-15 parts isopropanol as the co-solvent. This invention also discloses a method for using the aforementioned soft potassium magnesium alum flotation composite reagent. By introducing a nonionic surfactant as a stabilizer, this invention forms a mixed micelle system with the anionic collector, significantly improving the physical stability and shelf life of the reagent. In soft potassium magnesium alum flotation, the reagent of this invention can achieve a K⁺ recovery rate of over 96%, reduce the Na⁺ content to below 1.0%, and the reagent dosage is only 2000-350 g / t, demonstrating excellent flotation performance and promising industrial application prospects.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing flotation reagent technology, specifically relating to a soft potassium magnesium alum flotation composite reagent, and more particularly to a highly stable, long-term storable concentrated liquid preparation and its preparation method and application. Background Technology

[0002] Soft potassium magnesium sulfate (K₂Mg(SO₄)₂·6H₂O) is an important intermediate for potassium extraction from sulfate-type salt lake brines. It is also a high-quality, multi-element, chlorine-free potassium fertilizer, rich in potassium, magnesium, sulfur, and other nutrients, suitable for chlorine-sensitive crops such as fruit trees and tobacco. Currently, the extraction of soft potassium magnesium sulfate mainly employs the "conversion-flotation method," where potassium mixed salt ore is obtained through solar evaporation in salt fields, followed by flotation separation and purification. During the flotation process, the selectivity and stability of the collector are crucial.

[0003] In existing technologies, flotation collectors for soft potassium magnesia mainly include carboxylic acids, fatty amides, morpholines, and sulfonates. For example, Chinese patent publication CN115888990B discloses a composite flotation reagent for soft potassium magnesia, composed of alkylbenzene sulfonate (R-C6H4NaO3S) and a frother, which can obtain soft potassium magnesia concentrate with high recovery rates. However, this reagent is mostly prepared on-site, and the storage stability problem of the high-concentration surfactant complex system has not been solved. Furthermore, the collector component is singular, and its adaptability to complex ores needs improvement. Chinese patent publication CN120515587A proposes a sulfosuccinate salt collector, but similarly, it does not address the stability of the finished reagent. In addition, existing reagents are mostly powders or require on-site preparation, which leads to inconveniences in storage and transportation, and difficulties in dissolution and dispersion in industrial applications.

[0004] Therefore, it is of great significance to develop a high-concentration, stable, and highly effective soft potassium magnesium alum flotation composite reagent that can be directly applied in industrial applications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a soft potassium magnesium alum flotation composite reagent with reasonable composition, good stability and excellent flotation effect.

[0006] Another technical problem to be solved by the present invention is the preparation method and application of the aforementioned soft potassium magnesium alum flotation composite reagent.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: This invention relates to a soft potassium magnesium alum flotation composite reagent, characterized in that it is mainly composed of the following components by mass ratio: Main collector: Triethanolamine dodecylbenzenesulfonate 15-25; Collecting aid: Sodium methyl ester sulfonate of fatty acids 3-8; Stabilizer: 8-12g of polyoxyethylene sorbitan fatty acid ester; Foaming agent: 3-5% methyl isobutyl alcohol; Foam regulator: fatty alcohol polyoxyethylene ether 1-3; Dispersant: Sodium polyphosphate 0.5-1.5; Cosolvent: Isopropanol 8-15.

[0008] Furthermore, the compound agent is preferably a concentrated liquid preparation, dissolved in deionized water; and an appropriate amount of pH adjuster is added to make the final pH of the agent 8.0 to 9.0.

[0009] Furthermore, the mass ratio of the main collector to the auxiliary collector is preferably (4-8):1, and more preferably 4:1.

[0010] Furthermore, the preferred mass ratio of the total mass of the collector components (main collector + auxiliary collector) to the foaming agent methyl isobutyl methanol is (15-20):3, and even more preferably 17:3.

[0011] Furthermore, the polyoxyethylene sorbitan fatty acid ester is preferably Tween 80; the fatty alcohol polyoxyethylene ether is preferably the emulsifier MOA-7; and the pH adjuster is preferably triethanolamine.

[0012] Furthermore, the main collector, triethanolamine dodecylbenzenesulfonate, is preferably generated by an in-situ neutralization reaction of dodecylbenzenesulfonate or sodium dodecylbenzenesulfonate with triethanolamine.

[0013] The present invention also provides a method for preparing the above-mentioned soft potassium magnesium alum flotation composite reagent, comprising the following steps: (1) Preparation of base solution: Add the prescribed amount of deionized water, isopropanol and sodium polyphosphate to the reaction vessel, stir and heat to 40-45℃; under stirring conditions, add polyoxyethylene dehydrated sorbitan fatty acid ester and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until completely dissolved to obtain a uniform and transparent micelle base solution. (2) Pre-neutralization of the main collector: In another container, dodecylbenzenesulfonic acid and triethanolamine are mixed according to the stoichiometric ratio of the neutralization reaction, the reaction temperature is controlled at ≤50℃, and the reaction is stirred until clear to obtain a pre-neutralized solution of dodecylbenzenesulfonic acid triethanolamine salt; (3) Compounding of collector components: Under the condition of stirring, the pre-neutralized liquid obtained in step (2) is slowly added to the base solution in step (1); then the formulated amount of sodium fatty acid methyl ester sulfonate is added, and stirring is continued until it is completely dissolved and dispersed. (4) Addition of foaming agent and volume adjustment: Cool the system to below 35°C, add methyl isobutyl methanol, and stir evenly; add the remaining deionized water to the total amount of the formula, and adjust the pH to 8.0-9.0 with triethanolamine; continue stirring for 1-2 hours to homogenize; (5) Maturation and inspection: Stop stirring and let the prepared reagent stand for 24 to 48 hours to mature, so as to obtain a uniform and stable soft potassium magnesium alum flotation composite reagent.

[0014] Furthermore, the agent described in step (5) was placed at 4°C and 40°C for 7 days respectively, and there was no stratification, precipitation or crystallization.

[0015] The present invention further provides the application of the above-mentioned soft potassium magnesium alum flotation composite reagent in soft potassium magnesium alum flotation separation.

[0016] The present invention also discloses a flotation method for soft potassium magnesium alum, comprising the following steps: adding the soft potassium magnesium alum flotation composite reagent directly to the flotation slurry, or adding it after pre-diluting it with water to a working solution of 1-5 wt%, wherein the reagent dosage is 200-350 g / t of raw ore based on the total effective components of the collector; and performing flotation separation to obtain soft potassium magnesium alum concentrate.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention introduces polyoxyethylene dehydrated sorbitan fatty acid ester nonionic surfactants as stabilizers to form a mixed micelle system with anionic collectors, which significantly improves the physical stability and shelf life of the agent and solves the technical problem of easy layering and precipitation in high-concentration surfactant compound systems.

[0018] (2) A stepwise preparation process is adopted. First, a nonionic surfactant micelle substrate is constructed, and then an anionic collector is introduced. This avoids precipitation or flocculation that may occur when ionic surfactants and nonionic surfactants are directly mixed, thus ensuring the uniformity and stability of the system.

[0019] (3) The main collector is triethanolamine dodecylbenzenesulfonate, which improves the water solubility and low temperature stability of sodium dodecylbenzenesulfonate and enhances the applicability of the agent.

[0020] (4) The composite reagent of the present invention has excellent application effect in soft potassium magnesium alum flotation: the K⁺ recovery rate in the flotation concentrate can reach more than 96%, and the Na⁺ content can be reduced to less than 1.0%, which is better than the existing technology; at the same time, the reagent dosage is reduced to 200~350 g / t, which is economical.

[0021] (5) The pharmaceutical preparation of the present invention is a concentrated liquid preparation with a high content of active ingredients, which is convenient for industrial production, storage, transportation and use, and has broad industrial application prospects. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments. The raw materials used in the embodiments are all commercially available industrial grade or chemically pure.

[0023] Example 1: A soft potassium magnesium alum flotation composite reagent, with the following formula by mass percentage: Main collector: 20% triethanolamine dodecylbenzenesulfonate; Collector aid: 5% sodium methyl ester sulfonate of fatty acids; Stabilizer: 10% polyoxyethylene sorbitan fatty acid ester; Foaming agent: 4% methyl isobutyl alcohol; Foam conditioner: 2% fatty alcohol polyoxyethylene ether; Dispersant: 1% sodium polyphosphate; Co-solvent: 10% isopropanol; pH adjuster: Apply an appropriate amount to achieve a final pH of 8.5 for the reagent; Deionized water: Replenish to 100%.

[0024] Preparation method: (1) Preparation of base solution: Add deionized water (80% of the total amount), isopropanol and sodium polyphosphate to the reaction vessel, stir and heat to 42°C; add Tween 80 and MOA-7 in sequence while stirring, and continue stirring until completely dissolved to obtain a homogeneous and transparent base solution.

[0025] (2) Pre-neutralization of the main collector: Take dodecylbenzenesulfonic acid (the amount required to react with triethanolamine to generate 20% dodecylbenzenesulfonic acid triethanolamine salt) and triethanolamine (theoretical amount), add a small amount of water, control the temperature ≤45℃, stir the reaction for 30 min, and obtain a clear pre-neutralized solution.

[0026] (3) Collector component compounding: The pre-neutralized liquid is slowly added to the base solution under stirring; then sodium fatty acid methyl ester sulfonate is added and stirred until completely dissolved and dispersed.

[0027] (4) Addition of foaming agent and volume adjustment: Cool the system to 30°C, add methyl isobutyl methanol and stir evenly; add the remaining deionized water to the total volume, adjust the pH to 8.5 with triethanolamine; continue stirring for 1.5 h to homogenize.

[0028] (5) Maturation and testing: Stop stirring and let stand for 36 hours to mature. The resulting reagent is a uniform semi-transparent liquid. Stability test: After being placed at 4℃ and 40℃ for 7 days, there was no layering, precipitation or crystallization, and the appearance remained uniform.

[0029] Example 2 follows the same formulation and preparation method as Example 1, except that the formulation ratio is adjusted as follows: 15% main collector, 8% auxiliary collector, 12% stabilizer, 5% foaming agent, 1% foam regulator, 0.5% dispersant, 8% isopropanol, and the remainder is water (pH adjusted to 8.0).

[0030] The preparation steps are the same as in Example 1. The resulting drug is stable.

[0031] Example 3 follows the same formulation and preparation method as Example 1, except that the formulation ratio is adjusted as follows: 25% main collector, 3% auxiliary collector, 8% stabilizer, 3% foaming agent, 3% foam regulator, 1.5% dispersant, 15% isopropanol, and the remainder is water (pH adjusted to 9.0).

[0032] The preparation steps are the same as in Example 1. The resulting drug is stable.

[0033] Comparative Example 1 (Prior Art CN115888990B Example 2) The reagent was prepared according to the formulation of Example 2 in Chinese patent document CN115888990B: the collector was C. 18 H 29 NaO3S (R is a C12 straight-chain alkyl group), foaming agent is MIBC, mass ratio is 80:20, prepared on-site, not prepared as a concentrated solution.

[0034] flotation test Flotation tests were conducted using the conversion products of a potassium mixed salt ore from a salt lake. The chemical composition of the ore sample ranged as follows: K⁺ 12%–16%, Na⁺ 7%–10%, SO₄²⁻ 30%–35%, Cl⁻ 10%–15%, Mg²⁺ 3%–7%, with particles smaller than 0.15 mm accounting for 67.13%. Flotation pulp preparation: 180 g of the ore sample was mixed with 550 g of a co-saturated mother liquor of soft potassium magnesium sulfate and potassium chloride. The chemical composition of the mother liquor was as follows: K⁺ 1.0%–3.0%, Na⁺ 2.5%–4.0%, Mg²⁺ 3.5%–5.0%, SO₄²⁻ 6.0%–12.0%, Cl⁻ 11.0%–15.0%. The pulp temperature was controlled at 25℃. Flotation was performed using the reagents from Example 1 and Comparative Example 1, respectively, with a reagent dosage of 350 g / t based on the effective component of the collector. The flotation process was as follows: reagents were added and stirred for 2 min, followed by skimming for 4 min to obtain concentrate and tailings. The measured chemical composition of the ore sample used in this experiment was: K⁺ 12.06%, Na⁺ 8.70%, Mg²⁺ 6.14%, Cl⁻ 20.20%, SO₄²⁻ 31.30%.

[0035] Flotation results showed that, using the composite reagent of Example 1 of this invention, the concentrate obtained contained 18.89% K⁺ and 1.00% Na⁺, with a K⁺ recovery rate of 96.18%. In contrast, using the reagent of Comparative Example 1 under the same conditions, the concentrate contained 18.71% K⁺ and 1.00% Na⁺, with a K⁺ recovery rate of 95.66%. Compared to the comparative example, the reagent of this invention increased the K⁺ recovery rate by 0.52 percentage points, and slightly improved the K⁺ grade in the concentrate while maintaining the same Na⁺ content, indicating that the reagent of this invention has stronger collecting ability and better selectivity.

[0036] Stability test The reagents from Examples 1-3 were sealed and placed in a 54°C incubator for 14 days (accelerated aging test), and the changes in appearance were observed. The results showed that all samples remained uniform and transparent, without layering, precipitation, or crystallization, proving that the reagents of this invention have good long-term storage stability.

[0037] Drug dosage optimization experiment Flotation tests were conducted using the reagent from Example 1 at different dosages. When the reagent dosage was 150 g / t, the K⁺ content in the concentrate was 18.02%, the Na⁺ content was 1.12%, and the K⁺ recovery rate was 92.47%; at 250 g / t, the K⁺ content was 18.56%, the Na⁺ content was 1.05%, and the K⁺ recovery rate was 94.83%; at 350 g / t, the K⁺ content was 18.89%, the Na⁺ content was 1.00%, and the K⁺ recovery rate was 96.18%; and at 450 g / t, the K⁺ content was 18.91%, the Na⁺ content was 1.01%, and the K⁺ recovery rate was 96.21%. The results indicate that the suitable dosage is 200-350 g / t, and further increasing the dosage does not significantly improve the recovery rate.

[0038] In summary, the soft potassium magnesium alum flotation composite reagent provided by this invention has excellent flotation performance and stability, can achieve efficient separation of soft potassium magnesium alum, and has low reagent dosage, making it suitable for industrial applications.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A soft potassium magnesium alum flotation composite reagent, characterized in that, Based on mass ratio, it mainly consists of the following components: Main collector: Triethanolamine dodecylbenzenesulfonate 15-25; Collecting aid: Sodium methyl ester sulfonate of fatty acids 3-8; Stabilizer: 8-12g of polyoxyethylene sorbitan fatty acid ester; Foaming agent: 3-5% methyl isobutyl alcohol; Foam regulator: fatty alcohol polyoxyethylene ether 1-3; Dispersant: Sodium polyphosphate 0.5-1.5; Cosolvent: Isopropanol 8-15.

2. The soft potassium magnesium alum flotation composite reagent according to claim 1, characterized in that, The compound agent is a concentrated liquid preparation, dissolved in deionized water; then an appropriate amount of pH adjuster is added to make the final pH of the agent 8.0-9.

0.

3. The soft potassium magnesium alum flotation composite reagent according to claim 2, characterized in that, The pH adjuster is triethanolamine.

4. The soft potassium magnesium alum flotation composite reagent according to claim 1 or 2, characterized in that, The mass ratio of the main collector to the auxiliary collector is (4-8):1; the mass ratio of the total mass of the main collector and the auxiliary collector to the mass of the foaming agent is (15-20):

3.

5. The soft potassium magnesium alum flotation composite reagent according to claim 4, characterized in that, The mass ratio of the main collector to the auxiliary collector is 4:1; the mass ratio of the total mass of the collector components to the mass of the foaming agent is 17:

3.

6. The soft potassium magnesium alum flotation composite reagent according to claim 1 or 2, characterized in that, The main collector, triethanolamine dodecylbenzenesulfonate, is generated by an in-situ neutralization reaction of dodecylbenzenesulfonate or sodium dodecylbenzenesulfonate with triethanolamine.

7. The soft potassium magnesium alum flotation composite reagent according to claim 1 or 2, characterized in that, The stabilizer, polyoxyethylene sorbitan fatty acid ester, is Tween 80; the foam regulator, fatty alcohol polyoxyethylene ether, is emulsifier MOA-7.

8. A method for preparing the soft potassium magnesium alum flotation composite reagent according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Preparation of substrate solution: Add deionized water, isopropanol and sodium polyphosphate to the reaction vessel, stir and heat to 40-45℃; under stirring conditions, add polyoxyethylene dehydrated sorbitan fatty acid ester and fatty alcohol polyoxyethylene ether in sequence, and continue stirring until completely dissolved to obtain a uniform and transparent micelle substrate solution. (2) Pre-neutralization of the main collector: In another container, dodecylbenzenesulfonic acid and triethanolamine are mixed according to the stoichiometric ratio of the neutralization reaction, the reaction temperature is controlled at ≤50℃, and the reaction is stirred until clear to obtain a pre-neutralized solution of dodecylbenzenesulfonic acid triethanolamine salt; (3) Compounding of collector components: Under the condition of stirring, the pre-neutralized liquid obtained in step (2) is slowly added to the base solution in step (1); then the formulated amount of sodium fatty acid methyl ester sulfonate is added, and stirring is continued until it is completely dissolved and dispersed. (4) Addition of foaming agent and volume adjustment: Cool the system to below 35°C, add methyl isobutyl methanol, and stir evenly; add deionized water, and adjust the pH to 8.0-9.0 with triethanolamine; continue stirring for 1-2 hours to homogenize; (5) Maturation and inspection: Stop stirring and let the prepared reagent stand for 24 to 48 hours to mature, so as to obtain a uniform and stable soft potassium magnesium alum flotation composite reagent.

9. The use of the soft potassium magnesium alum flotation composite reagent according to any one of claims 1 to 7, characterized in that, The application described is to use the soft potassium magnesium alum flotation composite reagent as a soft potassium magnesium alum flotation separation reagent.

10. A method for flotation of soft potassium magnesium alum, characterized in that, The process includes the following steps: adding the soft potassium magnesium alum flotation composite reagent according to any one of claims 1 to 7 directly to the flotation pulp, or adding it after diluting it with water to a working solution of 1 to 5 wt%, with the reagent dosage being 200 to 350 g / t of raw ore based on the total effective components of the collector; Flotation separation was carried out to obtain soft potassium magnesium sulfate concentrate.