Beneficiation method for improving iron grade of ultra-fine particle magnetite by utilizing ultrasonic waves and dispersing agent

Abstract

The invention discloses a beneficiation method for improving the iron grade of ultra-micro-fine particle magnetite by using ultrasonic waves and a dispersing agent, which comprises the following steps: (1) taking an ultra-micro-fine particle magnetite sample in a container, and adding water for size mixing to obtain magnetite ore pulp; (2) an ultrasonic disperser is used for conducting ultrasonic dispersion on the ultra-fine particle magnetite ore pulp, agglomeration structures among mineral particles are destroyed, and the mineral particles are evenly dispersed in the ore pulp; (3) a dispersing agent is added, a layer of film is formed between magnetite particles and a liquid medium under the action of a stirrer, repulsive force among the particles is improved, and therefore the particles are prevented from being gathered again; and (4) the pretreated ore pulp is subjected to wet type magnetic separation operation through a wet type roller magnetic separator, and a magnetic separation concentrate product is obtained. By means of ultrasonic pretreatment and addition of a dispersing agent sodium hexametaphosphate, the grade of the ultra-fine particle magnetite magnetic concentrate can be effectively improved. The technological process is short and easy to operate and control, the grade of magnetic concentrate is improved, the mineral separation efficiency is improved, and the method is an efficient and economical ultra-fine particle magnetite separation method.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and relates to an ore dressing method which utilizes ultrasonic waves and a dispersant to improve the grade of ultrafine magnetite magnetic separation concentrate. Background Art

[0002] The magnetite ore with fine grains is a typical refractory iron ore. Although my country's iron ore resources are rich, the ore bodies are poor and fine. At present, about 30% of the ore grades in China are between 20% and 30%, which need to be enriched through mineral processing. Low-grade iron ore accounts for about 8%, with a reserve of about 5.2 billion tons, of which magnetite is the main mineral and is classified as ultra-poor magnetite resources.

[0003] In order to select high-grade magnetite concentrate, it is often necessary to finely grind the magnetite. As the grinding particle size decreases, the specific magnetic susceptibility of the magnetite monomer particles gradually decreases, and the coercive force gradually increases. The difference between the specific magnetic susceptibility of magnetite monomers and rich intergrowths is much smaller than the difference between magnetite and gangue minerals. The strong magnetic field in the magnetic separation area not only makes it very easy for magnetite monomers to form magnetic agglomerates, but also causes intergrowths and gangue to be mixed into the agglomerates, which in turn leads to the enhancement of the inclusion of gangue minerals and strongly magnetic ore particles, affecting the final concentrate grade.

[0004] Ultrasonic mineral processing is a technology that uses the physical effects of ultrasound in the ore pulp to disperse and pre-treat mineral particles. When ultrasound acts on a liquid containing mineral particles, it can produce a variety of physical phenomena such as cavitation effect, vibration effect and thermal effect. These phenomena can change the surface properties of mineral particles, such as enhancing the interaction between minerals and water, thereby improving the dispersion of minerals; or by destroying the adsorption layer on the surface of the mineral, improving the separation effect of the target mineral from other substances. In addition, ultrasound can penetrate into the interior of mineral particles and tiny gaps, and through its unique vibration and cavitation effects, it can effectively break the binding force between minerals, promote the separation of target minerals and impurities, and improve the efficiency and recovery rate of mineral processing. At present, ultrasonic technology has been widely used in mining, metallurgy and other fields.

[0005] Dispersants are used to change the surface electrical properties of fine minerals to make them charged or to disperse fine mineral particles due to steric hindrance. Sodium hexametaphosphate (sodium hexametaphosphate is a commonly used dispersant in mineral processing. It is a long-chain inorganic polyphosphate with a chemical formula of (NaPO3)6 and good water solubility. The phosphorus-oxygen bond in the sodium hexametaphosphate molecule breaks to form a negatively charged phosphate ion (PO4 3-), these negative charges can be adsorbed onto the surface of positively charged particles to form a double electric layer structure; since charges of the same kind repel each other, direct contact and aggregation between particles are prevented. In addition to the charge effect, long-chain or multi-ring sodium hexametaphosphate molecules can also be physically entangled or adsorbed on the surface of particles to form a protective film, increase the distance between particles, further reduce the probability of collision, and avoid agglomeration. Summary of the invention

[0006] In view of the defects existing in the prior art, the present invention proposes a beneficiation method for improving the iron grade of ultrafine magnetite using ultrasound and dispersants. The method first uses the mechanical vibration and cavitation effect generated by ultrasound (i.e., forming tiny bubbles in the liquid, which grow rapidly and collapse, releasing a large amount of energy) to break the agglomerates in the ultrafine magnetite and promote the uniform distribution of particles; and the dispersant added subsequently can form a thin film between the magnetite particles and the liquid medium, and can disperse the various charges on the surface of the mineral particles, showing a strong negative charge, which can hinder the aggregation of spherical particles with the same negative charge, thereby preventing the particles from re-aggregating. This method not only improves the dispersion efficiency of magnetite, but also ensures the dispersion stability over a long period of time, which is of great significance for improving product quality and performance. The present method can effectively improve the iron grade of ultrafine magnetite concentrate, thereby improving the utilization rate of my country's iron ore resources.

[0007] The present invention is achieved by adopting the following technical solutions:

[0008] 1. A method for beneficiating ultrafine magnetite by using ultrasound and dispersant to improve the iron grade, characterized by the following steps:

[0009] (1) taking an appropriate amount of ultrafine magnetite in a container, adding water to form a slurry with a concentration of 20-25 wt%;

[0010] (2) using an ultrasonic disperser to ultrasonically disperse the slurry prepared in step (1) to destroy the agglomeration structure between the mineral particles so that the mineral particles are evenly dispersed in the slurry, the processing time being 0 to 2 minutes;

[0011] (3) adding a dispersant to the slurry after the dispersion treatment in step (2) and stirring, wherein the dispersant is sodium hexametaphosphate, the amount of the dispersant is 500-1500 g / t, the stirring speed is 400-600 r / min; and the stirring time is 3-5 min.

[0012] (4) subjecting the ore pulp obtained in step (3) to magnetic separation to obtain magnetite magnetic separation concentrate and magnetic separation tailings.

[0013] The main phases of the ultrafine magnetite ore are: 48wt% magnetite, 5wt% hematite, 3wt% limonite, 1wt% pyrite and 43wt% gangue minerals;

[0014] The ultra-fine magnetite ore has a total iron grade of 36.88%, D 50 3.54μm, D 90 The particle size is 9.50 μm; the degree of magnetite dissociation is 91.2%.

[0015] The ultrasonic instrument is an ultrasonic cleaning machine of model JG-28K36;

[0016] The dispersant is sodium hexametaphosphate, and the preparation method of the dispersant is: weigh sodium hexametaphosphate in a beaker, and add water to make a solution with a concentration of 1%;

[0017] The magnetic separation operation adopts a wet drum magnetic separator with a magnetic field strength of 180mT.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. A beneficiation method for improving the iron grade of ultrafine magnetite by using ultrasound and dispersant is proposed. The use of ultrasound and dispersant can effectively prevent the aggregation of magnetic particles and non-magnetic particles, break the formation of magnetic agglomeration or release magnetic agglomeration, reduce the entrainment of gangue in the concentrate, and force the discharge of gangue; the addition of dispersant can not only increase the repulsive force between particles, but also form a protective layer on the surface of particles to prevent particles from re-agglomerating, which helps to maintain the long-term stability of the slurry, avoid the decline of sorting effect due to agglomeration, ensure that the particles are evenly distributed in the slurry, thereby improving the sorting effect, making the final product higher in purity and lower in impurity content.

[0020] 2. The above method of the present invention mainly pre-treats ultrafine magnetite slurry with ultrasound and the addition of dispersants, thereby improving the grade of magnetic separation concentrate, the process flow is relatively simple, easy to operate and control, can flexibly respond to different raw material conditions, improve the scope of application of the process, and has low production cost. In addition, due to the use of ultrasound and dispersants, magnetite particles are more evenly distributed in the slurry, reducing the entrainment of gangue minerals caused by agglomeration. Therefore, this method has significant advantages in improving magnetite separation efficiency, dispersion stability, magnetic separation effect, and improving product quality, and is an efficient, economical, and environmentally friendly method for separating fine magnetite. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, wherein:

[0022] Figure 1is a process flow chart of the present invention;

[0023] Figure 2 This is a picture of ultrafine magnetite slurry without ultrasonic dispersion;

[0024] Figure 3 This is a picture of ultrafine magnetite slurry after ultrasonic dispersion. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] Example 1

[0027] A method for beneficiating ultrafine magnetite by using ultrasound and dispersant to improve the iron grade of ultrafine magnetite, the specific steps of which are as follows:

[0028] (1) Water is added to the ultrafine magnetite ore to a concentration of 20 wt % to obtain an ultrafine magnetite slurry.

[0029] (2) dispersing the adjusted ultrafine magnetite slurry through an ultrasonic instrument for 2 minutes;

[0030] (3) adding a dispersant sodium hexametaphosphate solution to the ultrafine magnetite slurry, the dispersant dosage is 1000 g / t, stirring the slurry after adding the dispersant, the stirring speed is 500 r / min, and the stirring is uniformly stirred for 3 min;

[0031] (4) Under the condition of a magnetic field strength of 180 mT, a wet drum magnetic separator is used to perform magnetic separation on the treated ultrafine magnetite slurry to obtain magnetic concentrate and magnetic tailings.

[0032] The main phases of the ultrafine magnetite ore described in this embodiment are: magnetite content is 48wt%, hematite content is 5wt%, limonite content is 3wt%, pyrite content is 1wt%, and gangue mineral content is 43wt%;

[0033] The ultrafine magnetite ore in this example has a total iron grade of 36.88%, D 50 3.54μm, D 90 is 9.50μm; the degree of magnetite dissociation is 91.2%;

[0034] In this embodiment, the total iron grade of the magnetic concentrate treated with ultrasonic dispersion reaches 62.12%, and the iron recovery rate is 83.35%. Compared with the conventional ultrafine magnetite magnetic separation process, the grade is increased by 4.54%, and the iron recovery rate does not change much.

[0035] Example 2

[0036] A method for beneficiating ultrafine magnetite by using ultrasound and dispersant to improve the iron grade of ultrafine magnetite, the specific steps of which are as follows:

[0037] (1) Water is added to the ultrafine magnetite ore to a concentration of 20 wt % to obtain an ultrafine magnetite slurry.

[0038] (2) dispersing the adjusted ultrafine magnetite slurry through an ultrasonic instrument for 1 min;

[0039] (3) adding a dispersant sodium hexametaphosphate solution to the slurry after ultrasonic dispersion treatment, the amount of the dispersant is 1000 g / t, stirring the slurry after adding the dispersant, the stirring speed is 500 r / min, and the stirring is uniformly stirred for 3 min;

[0040] (4) Under the condition of a magnetic field strength of 180 mT, a wet drum magnetic separator is used to perform magnetic separation on the treated ultrafine magnetite slurry to obtain magnetic concentrate and magnetic tailings.

[0041] The main phases of the ultrafine magnetite ore described in this embodiment are: magnetite content is 48wt%, hematite content is 5wt%, limonite content is 3wt%, pyrite content is 1wt%, and gangue mineral content is 43wt%;

[0042] The ultrafine magnetite ore in this example has a total iron grade of 36.88%, D 50 3.54μm, D 90 is 9.50μm; the degree of magnetite dissociation is 91.2%;

[0043] In this embodiment, the total iron grade of the magnetic concentrate treated with ultrasonic dispersion reaches 60.74%, and the iron recovery rate is 84.73%. Compared with the conventional ultrafine magnetite magnetic separation process, the grade of the magnetic concentrate can be increased by 3.16%, and the iron recovery rate does not change much.

[0044] Finally, it should be noted that the above is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for beneficiating ultrafine magnetite by using ultrasound and dispersant to improve the iron grade of ultrafine magnetite, characterized in that Follow these steps: (1) taking an appropriate amount of ultrafine magnetite in a container, adding water to form a slurry with a concentration of 20-25 wt%; (2) using an ultrasonic disperser to ultrasonically disperse the slurry prepared in step (1) to destroy the agglomeration structure between the mineral particles so that the mineral particles are evenly dispersed in the slurry, the processing time being 0 to 2 minutes; (3) adding a dispersant to the slurry after the dispersion treatment in step (2) and stirring, wherein the dispersant is sodium hexametaphosphate, the amount of the dispersant is 500-1500 g / t, the stirring speed is 400-600 r / min; and the stirring time is 3-5 min. (4) subjecting the ore pulp obtained in step (3) to magnetic separation to obtain magnetite magnetic separation concentrate and magnetic separation tailings.

2. The method for beneficiating ultrafine magnetite by using ultrasound and dispersant according to claim 1, characterized in that: The main phases of the ultrafine magnetite ore in (1) are: magnetite content is 48wt%, hematite content is 5wt%, limonite content is 3wt%, pyrite content is 1wt%, and gangue mineral content is 43wt%; The ultra-fine magnetite ore has a total iron grade of 36.88%, D 50 3.54μm, D 90 The particle size is 9.50 μm; the degree of magnetite dissociation is 91.2%.

3. The method for beneficiating ultrafine magnetite by using ultrasound and dispersant according to claim 1, characterized in that: The ultrasonic instrument in (2) is a JG-28K36 ultrasonic cleaning machine.

4. The method for beneficiating ultrafine magnetite by using ultrasound and dispersant according to claim 1, characterized in that: The dispersant in (3) is sodium hexametaphosphate, and the preparation method of the dispersant is as follows: weigh sodium hexametaphosphate in a beaker, and add water to prepare a solution with a concentration of 1%.

5. The method for beneficiating ultrafine magnetite by using ultrasound and dispersant according to claim 1, characterized in that: The magnetic separation operation in (4) uses a wet drum magnetic separator with a magnetic field strength of 180mT.

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