A collector suitable for limestone type zinc oxide ore flotation and its flotation application method

Abstract

The application discloses a collector suitable for limestone type zinc oxide ore flotation and a flotation application method thereof. The collector is composed of 3-dodecyloxypropylamine hydrochloride and lauryl alcohol phosphate potassium with a molar ratio of 2-4:1. When used, 3-dodecyloxypropylamine and lauryl alcohol phosphate potassium are mixed into a 4-6% aqueous solution according to the molar ratio, and an equal molar amount of hydrochloric acid is added, and the system is reacted until it becomes a transparent homogeneous aqueous solution. The ore is ground and slurried, and 300-600 g / t dispersant, 500-1000 g / t activator and 300-500 g / t collector are added in sequence, and after each addition, stirring is carried out for 1-5 min, and roughing concentrate and roughing tailings are obtained through flotation. The roughing concentrate is cleaned for 3-4 times, 100-300 g / t depressant is added each time, the foam obtained through cleaning is zinc concentrate, and tailings are returned to the previous operation in sequence. The roughing tailings are cleaned for 2-3 times, only collector is added in the last section, 100-300 g / t activator and 100-200 g / t collector are added in each section in sequence, stirring is carried out for 1-5 min after each addition, and the material in the tank obtained through cleaning is the final tailings, and the concentrate is returned to the previous operation in sequence.

Description

Technical Field

[0001] This invention belongs to the field of mineral flotation technology, specifically relating to a collector suitable for the flotation of limestone-type zinc oxide ore and its flotation application method. Background Technology

[0002] Zinc oxide ores constitute a significant proportion of my country's zinc resources. Their main industrial minerals include smithsonite (ZnCO3) and hemimorphite (Zn4Si2O7(OH)2·H2O), with smithsonite being the most widely distributed and abundant typical zinc oxide mineral. Based on the composition of gangue minerals, zinc oxide ores can be classified into sandstone and limestone types. Sandstone-type zinc oxide ores are dominated by silicate minerals such as quartz and clay. Due to their complex mineral composition, fine grain size, and high content of primary and secondary slime, the beneficiation process is relatively complex, making it difficult to improve separation indicators. Limestone-type zinc oxide ores are dominated by carbonate minerals such as calcite and dolomite. The target mineral, smithsonite, and the gangue minerals both belong to the carbonate class, sharing similar surface properties and floatability, resulting in poor flotation selectivity and extremely high separation difficulty. A large amount of low-grade zinc oxide ore in my country has been stockpiled and abandoned due to a long-term lack of economically feasible beneficiation technologies, causing a serious waste of zinc resources. Therefore, developing a high-efficiency, low-consumption, and highly adaptable zinc oxide ore collector and its supporting flotation technology is of great significance for improving the comprehensive utilization rate of zinc resources in my country and ensuring the security of strategic non-ferrous metal supply.

[0003] In the flotation of limestone-type zinc oxide ores, smithsonite is often closely associated with carbonate gangues such as calcite and dolomite. These minerals are highly similar in crystal structure and surface metal sites (both are carbonates of zinc, calcium, and magnesium), and traditional collectors such as amines and fatty acids lack selectivity for these minerals. Simultaneously, zinc oxide ores commonly contain clay minerals such as chlorite and kaolinite, which easily generate fine-grained slime during grinding. This slime has a large specific surface area and high surface activity, easily forming a non-selective capping layer on the smithsonite surface, severely affecting the flotation recovery of the target mineral. Therefore, the development direction for the flotation of limestone-type zinc oxide ores is to improve the selectivity of collectors and develop a complementary flotation application process. Summary of the Invention

[0004] The first objective of this invention is to provide a collector suitable for the flotation of limestone-type zinc oxide ore; the second objective of this invention is to provide a method for applying the collector in flotation.

[0005] The first objective of this invention is achieved as follows: the collector suitable for flotation of limestone-type zinc oxide ore is composed of 3-dodecyloxypropylamine hydrochloride and potassium lauryl phosphate in a molar ratio of 2 to 4:1.

[0006] The second objective of this invention is achieved as follows: the flotation application method of the collector includes the following steps: A. Preparation of the collector: Mix 3-dodecyloxypropylamine and potassium lauryl phosphate according to the molar ratio, dissolve in water, and prepare an aqueous solution with a total solute mass fraction of 4-6%. Under stirring conditions, add industrial concentrated hydrochloric acid in an equal molar amount to 3-dodecyloxypropylamine, and continue stirring until the reaction system becomes a transparent homogeneous aqueous solution.

[0007] B. Slurry preparation: The limestone-type zinc oxide ore is crushed, ground, and mixed into a slurry.

[0008] C. Slurry flotation: Under stirring conditions, a dispersant of 300-600 g / t is added to the slurry, followed by a smithsonite activator of 500-1000 g / t, and then a prepared collector of 300-500 g / t. Each reagent is stirred for 1-5 minutes after addition, followed by aerated flotation to obtain flotation froth rougher concentrate and rougher tailings from the tank. The roughing concentrate is subjected to 3 to 4 cleaning processes. Calcite and dolomite inhibitors are added to each process at a rate of 100 to 300 g / t. The foam obtained from the cleaning process is the zinc concentrate. The tailings from the cleaning process are returned to the previous process in sequence, forming a closed loop. The roughing tailings are subjected to 2-3 scavenging processes. Except for the last stage where only 100-200 g / t of collector is added, each of the other stages first adds smithsonite activator at a dosage of 100-300 g / t, followed by the prepared collector at a dosage of 100-200 g / t. Each reagent is stirred for 1-5 minutes after addition. The material in the tank obtained from the scavenging process is the final tailings. The concentrate from the scavenging process is returned to the previous stage, forming a closed-loop cycle.

[0009] Compared with the prior art, the technical solution described in this invention has the following advantages: 3-Laurixamine, molecular formula C 15 H 33 NO, with a molecular weight of 243.43, contains both amino and ether polar groups and long-chain alkyl hydrophobic groups in its molecular structure. It can achieve selective adsorption through the synergistic effect of electrostatic attraction and hydrogen bonding. At the same time, it enhances the hydrophobic flotation process with its excellent surface activity, exhibiting superior collection performance compared to traditional dodecylamine.

[0010] Potassium dodecyl phosphate (C663-2000) 12 H 25 K₂O₄P, with a molecular weight of 342.49, has a phosphate group that can react with specific metal ions (such as Zn). 2+Selective chemisorption occurs, and the long-chain alkyl groups provide hydrophobic effects, exhibiting good selectivity and collection ability in the flotation separation of complex minerals such as smithsonite.

[0011] However, the aforementioned two collectors have limited solubility in aqueous solutions, making it difficult to fully utilize their effectiveness when used alone. This technical solution converts 3-dodecyloxypropylamine into hydrochloride salt using equimolar amounts of hydrochloric acid. On one hand, the protonation of the tertiary (or primary) amine to form a cationic ammonium salt enhances its water solubility and dispersibility. On the other hand, this cationic group not only preferentially adsorbs onto smithsonite, which has a higher surface negative charge density, through electrostatic attraction, but its long-chain alkyl groups can also pre-arrange in the slurry, providing hydrophobic binding sites for subsequent anionic collectors.

[0012] The phosphate group of potassium lauryl phosphate has a very strong coordinating ability, particularly for Zn. 2+ The selectivity stability constant is significantly higher than that for Ca 2+ and Mg 2+ This is because the Ca exposed on the surface of calcite and dolomite in limestone-type ores... 2+ and Mg 2+ Although both are metal ions, their ionic radius, polarization ability, and coordination field environment are similar to those of Zn. 2+ The differences are significant; the phosphate groups cannot form equally stable chemical bonds on their surface, thus achieving highly selective separation at the molecular level.

[0013] In this technical solution, the cationic 3-dodecyloxypropylamine hydrochloride preferentially adsorbs onto the surface of smithsonite, reducing its surface energy and neutralizing some of the charge; the anionic potassium lauryl phosphate is then firmly anchored to Zn²⁺ sites through chemical bonds. The two form a mixed hydrophobic film on the mineral surface, with interpenetrating and densely packed hydrophobic chains far exceeding those of a single collector, greatly enhancing the adhesion strength between bubbles and mineral particles, achieving a synergistic effect of strong adsorption and strong hydrophobicity.

[0014] Furthermore, the flotation process provided by this technical solution can fully guarantee the maximization of mineral processing efficiency and product grade. Based on the strong chemical anchoring effect of the prepared collector, the flotation process adopts a sufficient dosage scheme in the roughing stage to ensure that the target mineral surface is preferentially saturated and covered, thus promoting the full floatation of the target mineral.

[0015] During the beneficiation stage, carboxymethyl cellulose is used to selectively chelate and desorb the small amount of reagent remaining on the surface of calcite and dolomite, while having minimal impact on the already firmly chemically adsorbed smithsonite-collector complex, thus ensuring concentrate grade. During the scavenging stage, the addition of an activator not only activates the small amount of undumped smithsonite but also acts as a buffer to adjust the pulp pH and ionic strength, maintaining the collector's optimal dissociation state and achieving dynamic equilibrium of the beneficiation environment in a closed-loop cycle. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the technical solution described in this invention. Detailed Implementation

[0017] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the scope of protection of the present invention.

[0018] The collector for flotation of limestone-type zinc oxide ore according to the present invention is characterized in that the collector is composed of 3-dodecyloxypropylamine hydrochloride and potassium lauryl phosphate in a molar ratio of 2 to 4:1, wherein the 3-dodecyloxypropylamine hydrochloride is generated by reacting 3-dodecyloxypropylamine with an equimolar amount of hydrochloric acid.

[0019] The preferred molar ratio of 3-dodecyloxypropylamine hydrochloride to potassium lauryl phosphate is 3:1.

[0020] The collector is prepared according to the following method: Mix 3-dodecyloxypropylamine and potassium lauryl phosphate in the molar ratio described above, dissolve in water, and prepare an aqueous solution with a total solute mass fraction of 4-6%. Under stirring conditions, add an equal molar amount of industrial concentrated hydrochloric acid to 3-dodecyloxypropylamine, and continue stirring until the reaction system becomes a transparent homogeneous aqueous solution.

[0021] The flotation application method of the collector includes the following steps: A. Preparation of the collector: Mix 3-dodecyloxypropylamine and potassium lauryl phosphate according to the molar ratio, dissolve in water, and prepare an aqueous solution with a total solute mass fraction of 4-6%. Under stirring, add an equal molar amount of industrial concentrated hydrochloric acid (HCl mass fraction of 36-38%) to 3-dodecyloxypropylamine, and continue stirring until the reaction system becomes a transparent, homogeneous, and stable aqueous solution.

[0022] B. Slurry preparation: The limestone-type zinc oxide ore is crushed, ground, and mixed into a slurry.

[0023] C. Slurry flotation: Under stirring conditions, a dispersant of 300-600 g / t is added to the slurry, followed by a smithsonite activator of 500-1000 g / t, and then a prepared collector of 300-500 g / t. Each reagent is stirred for 1-5 minutes after addition, followed by aerated flotation to obtain flotation froth rougher concentrate and rougher tailings from the tank. The roughing concentrate is subjected to 3 to 4 cleaning processes. Calcite and dolomite inhibitors are added to each process at a rate of 100 to 300 g / t. The foam obtained from the cleaning process is the zinc concentrate. The tailings from the cleaning process are returned to the previous process in sequence, forming a closed loop. The roughing tailings are subjected to 2-3 scavenging processes. Except for the last stage where only 100-200 g / t of collector is added, each of the other stages first adds smithsonite activator at a dosage of 100-300 g / t, followed by the prepared collector at a dosage of 100-200 g / t. Each reagent is stirred for 1-5 minutes after addition. The material in the tank obtained from the scavenging process is the final tailings. The concentrate from the scavenging process is returned to the previous stage, forming a closed-loop cycle.

[0024] In the collector preparation process, the total solute mass fraction of the aqueous solution is preferably 5%. The concentrated industrial hydrochloric acid is added under stirring conditions, with the addition rate controlled to maintain the temperature of the reaction system at 40-50°C. The stirring time is 10 minutes. The stable aqueous solution refers to a solution that shows no stratification or precipitation after standing for 24 hours.

[0025] In the slurry preparation process, the slurry has a grinding fineness of -0.074 mm and a content of 60-70%, and the slurry liquid-solid ratio is 2:1.

[0026] In the slurry flotation process, the dispersant added during the flotation operation is water glass, preferably at a dosage of 500~600g / t, and the stirring time is 3~5min; the smithsonite activator added is ethylenediamine phosphate, preferably at a dosage of 800~1000g / t, and the stirring time is 2~4min.

[0027] In the slurry flotation process, the amount of collector added during the flotation operation is 450~500g / t, and the stirring time is 1~2min.

[0028] In the slurry flotation process, the amount of collector added during the scavenging operation is 100g / t, and the stirring time is 1~2min.

[0029] In the pulp flotation process, the calcite and dolomite inhibitors added in the fine-graining operation are carboxymethyl cellulose, and the stirring time is 2-3 minutes.

[0030] In the slurry flotation process, the smithsonite activator added in the scavenging operation is ethylenediamine phosphate, and the stirring time is 2-3 minutes.

[0031] Example 1

[0032] The limestone-type zinc oxide ore in Lanping, Yunnan Province, has a zinc grade of 8.29% and an oxidation rate of 85.72%. Zinc mainly exists in the form of smithsonite, and the gangue minerals are mainly carbonate minerals such as calcite and dolomite.

[0033] A. Preparation of the collector: 3-Dodecyloxypropylamine and potassium lauryl phosphate were mixed in a molar ratio of 3:1, dissolved in water, and prepared as an aqueous solution with a total solute mass fraction of 5%. Under stirring, an equimolar amount of concentrated industrial hydrochloric acid was added, with the addition rate controlled to maintain the temperature of the reaction system at 40-50℃. After the addition was complete, stirring was continued for 10 minutes until the reaction system became a transparent, homogeneous, and stable aqueous solution.

[0034] B. Slurry preparation: Crush the limestone-type zinc oxide ore to -2mm, then take 500g of ore sample and place it in a mill, add 500ml of water and grind it to a fineness of -0.074mm content of 65%, place the ore sample in a 1.5L flotation cell and adjust the slurry to a liquid-solid ratio of 2:1.

[0035] C. Slurry flotation: Under stirring conditions, add water glass dispersant at a dosage of 500 g / t to the slurry and stir for 5 min. Then add ethylenediamine phosphate activator for smithsonite at a dosage of 1000 g / t and stir for 3 min. Next, add the prepared collector at a dosage of 450 g / t and stir for 2 min. Then, carry out aerated flotation to obtain flotation froth rougher concentrate and rougher tailings of the material in the tank. The roughing concentrate was placed in a 1.0L flotation machine and subjected to three cleaning processes. Carboxymethyl cellulose (CMC) was added in cleaning process I, 200g / t in cleaning process II, and 100g / t in cleaning process III. The mixture was stirred for 2 minutes after each addition. The foam obtained after the three cleaning processes was the zinc concentrate with a zinc grade of 31.22% and a zinc recovery rate of 85.35%. The tailings from the cleaning processes were returned to the previous process, forming a closed-loop cycle. The roughing tailings are subjected to three scavenging processes. In scavenging operations I and II, ethylenediamine phosphate activator is added at a dosage of 300 g / t and stirred for 3 min. Then, the prepared collector is added at a dosage of 100 g / t and stirred for 2 min. In scavenging operation III, only the collector is added at a dosage of 100 g / t and stirred for 2 min. The material in the tank after the three scavenging operations is the final tailings, with a zinc grade of 1.57% and a recovery rate of 14.65%. The concentrate from the scavenging operations is returned to the previous operation, forming a closed-loop cycle.

[0036] Example 2

[0037] The limestone-type zinc oxide ore in Zhaotong, Yunnan Province, has a zinc grade of 11.88% and an oxidation rate of 78.34%. Zinc mainly exists in the form of smithsonite, and the gangue minerals are mainly carbonate minerals such as calcite and dolomite.

[0038] A. Preparation of the collector: 3-Dodecyloxypropylamine and potassium lauryl phosphate were mixed in a molar ratio of 3:1, dissolved in water, and prepared as an aqueous solution with a total solute mass fraction of 5%. Under stirring, an equimolar amount of concentrated industrial hydrochloric acid was added, with the addition rate controlled to maintain the temperature of the reaction system at 40-50℃. After the addition was complete, stirring was continued for 10 minutes until the reaction system became a transparent, homogeneous, and stable aqueous solution.

[0039] B. Slurry preparation: Crush the limestone-type zinc oxide ore to -2mm, then take 500g of ore sample and place it in a mill, add 500ml of water and grind it to a fineness of -0.074mm content of 70%, place the ore sample in a 1.5L flotation cell and adjust the slurry to a liquid-solid ratio of 2:1.

[0040] C. Slurry flotation: Under stirring conditions, add water glass dispersant at a dosage of 600 g / t to the slurry and stir for 5 min. Then add ethylenediamine phosphate activator for smithsonite at a dosage of 800 g / t and stir for 3 min. Next, add the prepared collector at a dosage of 500 g / t and stir for 2 min. Then, carry out aerated flotation to obtain flotation froth rougher concentrate and rougher tailings of the material in the tank. The roughing concentrate was placed in a 1.0L flotation machine and subjected to three cleaning processes. Carboxymethyl cellulose (CMC) was added in cleaning process I, 200g / t in cleaning process II, and 100g / t in cleaning process III. The mixture was stirred for 3 minutes after each addition. The foam obtained after the three cleaning processes was the zinc concentrate with a zinc grade of 33.72% and a zinc recovery rate of 87.73%. The tailings from the cleaning processes were returned to the previous process, forming a closed-loop cycle. The roughing tailings are subjected to three scavenging processes. In scavenging operations I and II, ethylenediamine phosphate activator is added at a dosage of 300 g / t and stirred for 3 min. Then, the prepared collector is added at a dosage of 100-200 g / t and stirred for 2 min. In scavenging operation III, only the collector is added at a dosage of 100 g / t and stirred for 2 min. The material in the tank after the three scavenging operations is the final tailings, with a zinc grade of 2.11% and a recovery rate of 12.27%. The concentrate from the scavenging operations is returned to the previous operation, forming a closed-loop cycle.

Claims

1. A collector suitable for flotation of limestone-type zinc oxide ore, characterized in that, The collector is composed of 3-dodecyloxypropylamine hydrochloride and potassium lauryl phosphate in a molar ratio of 2 to 4:

1.

2. The collector according to claim 1, characterized in that, The molar ratio of 3-dodecyloxypropylamine hydrochloride to potassium lauryl phosphate is 3:

1.

3. The collector according to claim 1, characterized in that, The collector is prepared according to the following method: Mix 3-dodecyloxypropylamine and potassium lauryl phosphate in the molar ratio described above, dissolve in water, and prepare an aqueous solution with a total solute mass fraction of 4-6%. Under stirring conditions, add an equal molar amount of industrial concentrated hydrochloric acid to 3-dodecyloxypropylamine, and continue stirring until the reaction system becomes a transparent homogeneous aqueous solution.

4. A flotation application method for the collector according to any one of claims 1 to 3, characterized in that, The process includes the following steps: A. Preparation of the collector: 3-dodecyloxypropylamine and potassium lauryl phosphate are mixed in the molar ratio described above, dissolved in water, and prepared into an aqueous solution with a total solute mass fraction of 4-6%. Under stirring conditions, an industrial concentrated hydrochloric acid with an equal molar amount to 3-dodecyloxypropylamine is added, and stirring is continued until the reaction system becomes a transparent homogeneous aqueous solution. B. Slurry preparation: Crushing, grinding, and preparing the limestone-type zinc oxide ore into a slurry; C. Slurry flotation: Under stirring conditions, a dispersant of 300-600 g / t is added to the slurry, followed by a smithsonite activator of 500-1000 g / t, and then a prepared collector of 300-500 g / t. Each reagent is stirred for 1-5 minutes after addition, followed by aerated flotation to obtain flotation froth rougher concentrate and rougher tailings from the tank. The roughing concentrate is subjected to 3 to 4 cleaning processes. Calcite and dolomite inhibitors are added to each process at a rate of 100 to 300 g / t. The foam obtained from the cleaning process is the zinc concentrate. The tailings from the cleaning process are returned to the previous process in sequence, forming a closed loop. The roughing tailings are subjected to 2-3 scavenging processes. Except for the last stage where only 100-200 g / t of collector is added, each of the other stages first adds smithsonite activator at a dosage of 100-300 g / t, followed by the prepared collector at a dosage of 100-200 g / t. Each reagent is stirred for 1-5 minutes after addition. The material in the tank obtained from the scavenging process is the final tailings. The concentrate from the scavenging process is returned to the previous stage, forming a closed-loop cycle.

5. The flotation application method of the collector according to claim 4, characterized in that, In the process of preparing the collector, the industrial concentrated hydrochloric acid is added under stirring conditions, and the addition rate is such that the temperature of the reaction system is controlled at 40~50℃.

6. The flotation application method of the collector according to claim 4, characterized in that, In the process of preparing the collector, the stirring time is 10 minutes.

7. The flotation application method of the collector according to claim 4, characterized in that, In the slurry preparation process, the slurry has a grinding fineness of -0.074 mm and a content of 60-70%, and a liquid-to-solid ratio of 2:

1.

8. The flotation application method of the collector according to claim 4, characterized in that, In the slurry flotation process, the amount of collector added during the flotation operation is 450~500g / t, and the stirring time is 1~2min.

9. The flotation application method of the collector according to claim 4, characterized in that, In the slurry flotation process, the amount of collector added during the scavenging operation is 100g / t, and the stirring time is 1~2min.

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