A method of mineral processing

Abstract

The application discloses a beneficiation method, which is suitable for efficient pre-concentration of various target ores, can be combined with a flotation process, saves a large amount of flotation reagent cost, and greatly reduces subsequent chemical waste residue and wastewater emission pollution. The method comprises the following steps: adding a heavy medium with preset characteristics and a density between target ores and main gangue tailings into target ore raw materials, adding water to the obtained mixed ore materials to prepare a pulp, and then feeding the pulp into a spiral beneficiation chute; under the screening of the beneficiation chute, a target ore, a heavy medium and a gangue tailing flow are formed; on the basis that the target ore and the gangue tailing have been separated by the heavy medium, the gangue tailing is separated from the ore materials, so that the gangue tailing and the target ore are separated; and the target ore and the heavy medium are separated by using the preset characteristics of the heavy medium, and a preliminary beneficiation process is completed. The beneficiation process can solve the technical problem that two minerals are too close in density, separation is difficult, and multiple repeated separation operations are required.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ore dressing, in particular to a spiral chute ore dressing method using heavy medium. BACKGROUND

[0002] The existing ore dressing technology, in the target ore and gangue density close to the mineral, such as oxidized copper ore, often contains malachite, siliceous malachite, water chalcoalumite, etc. When the spiral chute ore dressing is running, the pulp film flow will be mixed with the intermediate ore belt between the two minerals with too close density, which will lead to the difficulty in separation, and the repeated separation operation will increase the cost of ore dressing. If the target ore enrichment degree is not enough in the previous spiral ore dressing process, and too much impurity mineral with close density is carried, then it will lead to the need to add various chemical agents in the subsequent flotation process, thereby greatly increasing the cost, and greatly increasing the amount of chemical waste and wastewater, polluting the environment.

[0003] And using the traditional heavy medium added heavy liquid ore dressing, although it can separate two minerals with close density, but it is in the high-speed rotation of the cyclone to make the heavy medium suspended in the liquid to form a heavy liquid flow, the heavy liquid running pressure of the cyclone heavy medium is high, the equipment loss is large, and a complete set of facilities such as medium discharge and medium regeneration is also needed, which has the problems of high cost, complex process, and long time period required for ore dressing.

[0004] In view of the above problems, there is an urgent need for an ore dressing method that can efficiently separate minerals with close density with simple process and low cost. SUMMARY

[0005] In view of the above problems, the present application provides an ore dressing method which does not need a heavy liquid separation method, and can realize efficient, simple and low-cost separation of minerals with close density by using a spiral chute, and the specific steps include:

[0006] S1, adding a heavy medium with a preset characteristic significantly different from the target ore and a density between the target ore and the main gangue tailings to the target ore raw material to obtain a mixed ore material;

[0007] S2, after the mixed ore material obtained in S1 is slurried with water, it is sent into a spiral ore dressing chute, and under the screening of the ore dressing chute, a target ore, a heavy medium and a gangue tailings mineral flow belt are formed in sequence;

[0008] S3, on the basis that the target ore and the gangue tailings mineral flow belt have been separated by the heavy medium mineral flow belt, the gangue tailings are separated from the ore material at the discharge port of the spiral chute, thereby realizing the separation of the gangue tailings and the target ore;

[0009] S4, separating the target ore and the heavy medium by using preset characteristics of the heavy medium to complete the primary beneficiation process.

[0010] Preferably, in step S3, the spiral chute is provided with at least two discharge outlets, one of which is used to collect the gangue tailings stream, and the remaining discharge outlets are used to collect at least one of the target ore stream and the heavy medium stream, or one of which is used to collect the gangue tailings stream, and the remaining discharge outlets are used to collect at least one of the target ore stream and the heavy medium stream.

[0011] Preferably, the target ore is one of non-magnetic ores, and the preset characteristics of the heavy medium are magnetic, and in step S4, the target ore and the heavy medium are separated by using the magnetic difference between the target ore and the gangue tailings to pass the ore through a magnetic separation mechanism.

[0012] Preferably, the target ore is copper ore, and before step S1, the target ore is first crushed and ground to a particle size of more than 90% of the copper ore, and then the magnetic minerals in the target ore are separated out by a magnetic separator.

[0013] Preferably, in step S4, the target ore stream is taken out of the discharge outlet at the bottom of the spiral chute and passed through a magnetic separator to remove the magnetic heavy medium.

[0014] Preferably, the target ore is one of non-conductive ores, and the preset characteristics of the heavy medium are conductive, and in step S4, the target ore and the heavy medium are separated by using the conductivity difference between the target ore and the gangue tailings to pass the ore through a traditional electrostatic separation method.

[0015] Preferably, the particle size of the heavy medium is larger than that of the target ore, and in step S4, the target ore and the heavy medium are separated by using the size difference between the target ore and the gangue tailings to pass the ore through a traditional sieve.

[0016] Preferably, the target ore is one of oxidized copper ore, phosphate ore, spodumene ore, fluorite ore, and calcite ore.

[0017] Preferably, it further comprises step S5 of further separating and recovering the heavy medium entrained in the gangue tailings obtained in step S3.

[0018] Preferably, the spiral beneficiation chute comprises an intermediate column and a chute body mounted to the intermediate column, the chute body is provided with sieve patterns, the sieve patterns divide the chute body into three parts with decreasing smoothness from inside to outside, the sieve patterns of the middle part are opposite to the sieve patterns of the two sides in inclination direction, and the middle part accounts for one-third to one-half.

[0019] Preferably, in step S1, the mass ratio of the added heavy medium and the target ore raw material is 0.4-1.0:1.0.

[0020] Compared with the prior art, the present application has the beneficial effect that: by artificially adding customized heavy medium particles with preset characteristics, the density of which is between that of the target ore and the tailings, and through the spiral chute, the heavy medium particles squeeze away the minerals with a density higher than and lower than their own, forming a wider intermediate density film flow ore belt width, thereby achieving the beneficiation effect of conveniently intercepting and obtaining higher grade and higher recovery rate of minerals. That is, the core of the present process is to skillfully use the heavy medium with an intermediate density and make the heavy medium have different characteristics for the target ore. The minerals with close densities that are difficult to separate by traditional spiral beneficiation are converted into the target ore and the heavy medium which are relatively easy to separate. Although the densities of the target ore and the heavy medium are closer, based on the different characteristics of the two, the separation will be relatively easy. The difficulty of separating minerals with small density difference is reasonably resolved, the heavy medium can be recycled, and the traditional spiral beneficiation process can also be used, which has the advantages of simple process, low cost and high efficiency. The present technology has positive significance for the low-grade polymetallic refractory minerals that exist universally at home and abroad, and is suitable for efficient pre-concentration of various target ores. It can be combined with the flotation process to save a lot of flotation reagent cost. Compared with the traditional spiral beneficiation process, it also greatly reduces the chemical waste residue and wastewater discharge of the subsequent flotation process, reducing pollution. Compared with the heavy medium separation technology, the present technology has the advantages of low cost, simple and efficient process. In addition, the spiral chute design in the present technology, combined with the customized heavy medium process, can improve the beneficiation and separation effect. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the process flow chart of the copper ore embodiment in the present application;

[0022] Figure 2 is the overall view of the spiral beneficiation chute in the embodiment of the present application;

[0023] Figure 3 is the data table after the oxidation copper ore is removed. DETAILED DESCRIPTION

[0024] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described with reference to the drawings, but the protection scope of the present application is not limited to the following description.

[0025] The present application is particularly suitable for screening target ores and tailings with close densities. Of course, it is also applicable to minerals with large density differences, but the traditional spiral beneficiation can be used to separate minerals with large density differences. The process includes the following steps:

[0026] S1, add heavy medium with preset properties and density between target ore and main gangue tailings to the target ore raw material to obtain mixed ore material; of course, the ore material is subjected to traditional pretreatment such as crushing and grinding, so that the target mineral is in a dissociated particle size, and the customized heavy medium can be directly added before the beneficiation process.

[0027] S2, the ore material to which the heavy medium is added in S1 is subjected to mixing and stirring to obtain mixed ore material; of course, the mixed ore material needs to be stirred into ore slurry by adding water before being fed into the spiral beneficiation chute, and the heavy medium will squeeze away the minerals with a density higher than or lower than itself due to the density between the target ore and the gangue tailings, forming a relatively wide intermediate density film flow ore belt width, so that the ore material will gradually form the target ore, the heavy medium, and the gangue tailings ore material belt arranged in sequence under the screening of the spiral chute.

[0028] S3, based on the separation of the target ore and the gangue tailings by the heavy medium, the gangue tailings are separated from the ore material by intermediate interception or a separate discharge port at the bottom of the spiral chute (the position, number, and size of the discharge port are matched with the proportion of the target ore and the tailings and the heavy medium), so as to realize the preliminary separation of the gangue tailings and the target ore; at this time, only the preliminary separation of the gangue tailings is realized, and a small amount of heavy medium is mixed in the gangue tailings, the target ore discharge port is also mixed with heavy medium, but the main gangue tailings are basically not mixed, and other minerals are also mixed in the heavy medium.

[0029] S4, the heavy medium has specific properties that are significantly different from the properties of the target ore, such as particle size, electrical conductivity, or magnetism, etc., and the target ore and the heavy medium are separated by the difference in properties between the heavy medium and the target ore to complete the preliminary beneficiation process.

[0030] In step S1, the mass ratio of the added heavy medium to the target ore raw material is 0.1-1.0:1.0, and the heavy medium needs to have sufficient amount, so as to ensure that it can form a wide ore belt, which not only enables the target ore and the gangue to be fully separated, but also facilitates the operation of the separation process and easy collection.

[0031] In step S3, the spiral chute is provided with at least two discharge ports, taking two discharge ports as an example, one discharge port is used for separating the gangue tailings (which may contain part of the heavy medium), and the other discharge port is used for collecting the target ore and the heavy medium, and then separating the heavy medium and the target ore. Preferably, three discharge ports are provided, one of which is used for preliminary separation of the gangue tailings (which may contain part of the heavy medium), the second is used for preliminary separation of the target ore (which may contain part of the heavy medium), and the relative not to add the heavy medium The ore separation process contains a small amount of gangue, and the heavy medium contained in the heavy medium is slightly more, but the subsequent heavy medium separation process is much easier. The middle discharge port is used for preliminary collection of the heavy medium (the position and width of the discharge port can be controlled, and the collected heavy medium is basically pure, which is convenient for recycling). Compared with two discharge ports, three discharge ports also preliminarily separate the heavy medium, reduce the content of the target ore, and reduce the difficulty of separating the heavy medium and the target ore. Of course, the heavy medium ore stream and the gangue ore stream can be further separated.

[0032] In an embodiment, the target ore is one of non-magnetic ores, and the preset characteristics of the heavy medium are magnetic. In step S4, the magnetic difference between the target ore and the gangue tailings is used to separate the target ore and the heavy medium through a magnetic separation mechanism. Since the ore separation through the magnetic separation mechanism is a conventional technical means, and is not the core of the present application, the specific structure and method of the magnetic separation process are not described here. Of course, since the target ore is non-magnetic, after the ore is crushed in the early stage, a step of magnetic separation can be performed first to separate the magnetic impurities in the ore. In this way, when the heavy medium and the target ore are separated later, the heavy medium obtained by separation does not contain magnetic impurities.

[0033] In another embodiment, the target ore is one of non-conductive ores, and the preset characteristics of the heavy medium are conductive. In step S4, the conductive difference between the target ore and the gangue tailings is used to separate the target ore and the heavy medium through a conventional electrostatic separation method. Since the ore separation through the electrostatic separation method is a conventional technical means, and is not the core of the present application, the specific structure and method of the process are not described here. Of course, since the target ore is insulating, after the ore is crushed in the early stage, a step of electrostatic separation can be performed first to separate the conductive impurities in the ore. In this way, when the heavy medium and the target ore are separated later, the heavy medium obtained by separation does not contain conductive impurities.

[0034] In another embodiment, the particle size of the heavy medium is greater than that of the target ore, of course, the ore can be ground in the pretreatment stage to have a desired particle size range, so the heavy medium can also be customized to a reasonable size. In step S4, the particle size difference between the target ore and the gangue tailings is used to separate the target ore and the heavy medium through a traditional screen. Since the screen separation method is the most basic and common technical means, and is not the core of the present application, the specific structure and method of this process will not be described here.

[0035] In the above several embodiments, the heavy medium and target ore separation device can be directly placed at the discharge port of the spiral chute, so that the discharge port of the spiral chute can be directly used as the feed port of the next process.

[0036] In addition, the process also includes step S5, which is to further separate and recover the heavy medium entrained in the gangue tailings obtained in step S3. Because the heavy medium and the gangue do not have the characteristic difference between the heavy medium and the target ore, this separation can use a traditional separation process, of course, the heavy medium in the gangue can also be selected not to be recovered, because the content is not high.

[0037] In this process, a spiral chute is also needed, and a traditional spiral chute can also achieve good results, but in order to further improve the separation effect, the present application also redesigns the spiral chute for this heavy medium process. The spiral separation chute comprises an intermediate column and a chute body mounted on the intermediate column, the chute body is provided with a screen ridge, the screen ridge divides the chute body into three parts with decreasing smoothness from inside to outside, wherein the screen ridge of the middle part is opposite to the screen ridge of the two sides in inclination direction, and the middle part accounts for one third to one half. The intermediate column and the chute body are also provided with a vibration structure. The above-mentioned chute body design is to cooperate with the heavy medium, from inside to outside, the density is arranged from large to small, the smoothness of the outermost side is the smallest, but the mineral density is smaller, so it is easier to form a flow rate difference, and the opposite inclination direction of the convex ridge can make the heavy medium more easily separated from the two sides, so that the mineral flow boundary is more obvious, which is more conducive to the collection and separation of the discharge port.

[0038] Taking a non-magnetic ore as an example, the process is used to separate and separate the non-magnetic target mineral particles and the gangue mineral particles in the ore slurry, and the general process flow is as follows:

[0039] S1, a method for applying heavy medium film flow separation in a spiral chute separation device, a pre-made heavy medium (preset characteristics are magnetic) powder is added to the target mineral powder raw material;

[0040] S2, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, S1 said pre-made heavy medium powder density is between the density of two minerals to be separated, and has a density difference of 0.2 or more for each of the two minerals to be separated;

[0041] S3, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, S2 said pre-made heavy medium powder mixed with the target mineral in an amount of 2:1 by weight;

[0042] S4, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, the mixed mineral powder obtained in S3 is added with water to form a slurry, and the concentration of the slurry is 50% or less by weight of solid and liquid;

[0043] S5, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, the slurry in S4 is fed into the spiral chute, and the slurry flows down along the spiral chute to form centrifugal motion;

[0044] S6, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, the slurry in S5 has a running width that is expanded in the centrifugal motion of the spiral chute, forming a slurry film flow;

[0045] S7, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, the slurry film flow in S6 contains mineral particles with suitable looseness, wherein particles of different densities are crowded and collide with each other, low-density particles are pushed away from the circular peripheral channel by high-density particles, and gradually form a density gradient circular peripheral banding operation of mineral particles;

[0046] S8, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, the slurry in S7 is basically separated by the density gradient circular peripheral banding operation of mineral particles, forming a circular peripheral banding film flow of mineral particles arranged in order, including target minerals with larger density, heavy medium with medium density, and gangue tailings with smaller density;

[0047] S9, a method of applying heavy medium film flow beneficiation in a spiral chute beneficiation device, in S8, the spiral chute beneficiation device is provided with at least two discharge ports, one of which is away from the center column of the device to collect the relatively small density gangue mineral containing heavy medium, and the other is close to the center column of the device to collect the relatively large density target mineral containing heavy medium.

[0048] Take copper ore as an example, the main process flow is as follows: first, the copper ore is crushed and ground to a particle size of more than 90% of the copper ore, and the magnetic minerals in the ore powder are separated out by a magnetic separator, and the remaining non-magnetic minerals are mixed with the heavy medium powder with magnetism in a suitable proportion, and then water is added to form a slurry, which is sent into the spiral chute for downward movement to form a centrifugal film flow of particles, and two kinds of ore slurry produced from the bottom of the spiral chute are separated by a magnetic separator to remove the heavy medium with magnetism, and then two kinds of minerals with different densities are obtained: heavy copper concentrate and light gangue tailings, realizing efficient pre-concentration of copper ore before flotation. Specific embodiments

[0050] The following takes malachite copper oxide ore as an example to explain the process of the patent in detail, and other mineral species will not be listed here. Compared with the present embodiment, the process of other mineral species can be combined with the existing technology, and the specific process steps are explained as follows:

[0051] The raw ore is malachite copper oxide ore from Zambia, Africa, containing 0.665% copper.

[0052] Referring to Figure 1 , the beneficiation method includes the following steps:

[0053] S1: The raw copper oxide ore is coarsely crushed by an eccentric crusher to obtain a first crushed material below 20 mm, and the material on the screen is fed into a cone crusher for secondary crushing. The linear vibrating screen and the cone crusher form a closed loop screening and crushing route. After three cycles, the raw ore is crushed to 5 mm or less, accounting for 85-95%, and then fed into a ball mill for grinding. The ball mill produces a material with a particle size of 0.074 mm or less, accounting for 70%, which is then fed into a stirring barrel with water to obtain a slurry with a concentration of 30-40%;

[0054] S2: The slurry of S1 is sent to a magnetic separator to remove the magnetic minerals in the raw ore, and the non-magnetic minerals are mixed with the heavy medium powder with magnetism in a ratio of 1:1 to form a transition heavy medium slurry. The density of the copper oxide mineral in the slurry is about 3.9, the density of the gangue tailings is about 2.65, and the density of the heavy medium is artificially set at about 3.3. The particle size of the heavy medium is as close as possible to the particle size of the target mineral, both of which are 70% below 0.074 mm.

[0055] Please refer to Figure 2 , S3: The slurry in S2 is sent to a beneficiation spiral chute for separation, the diameter of the beneficiation spiral chute is 1.2 meters, the pitch is 0.72 meters, and there are 5 turns. Please refer to Figure 2, the mineral slurry is formed into different density mineral film flow particles by rotating along the multi-turn spiral chute, including different density particles of heavy medium being sequentially graded by density under the action of centrifugal force, and after the mineral particles are graded, a heavy mineral zone, a heavy medium zone and a light mineral zone are formed, wherein the heavy medium zone is located between the heavy mineral zone and the light mineral zone, and can separate the heavy mineral zone and the light mineral zone to a sufficient width for convenient interception, and the three outlets at the bottom of the spiral chute are collected: a mixture of heavy mineral and heavy medium A, a heavy medium concentrate B, and a mixture of light tailings and heavy medium C; if the spiral chute is used for mineral separation without the participation of heavy medium, the running mineral film flow will be difficult to separate due to the too close separation of the intermediate mineral zone between the concentrate and the tailings, and the mineral separation needs to be repeated multiple times, increasing the mineral separation cost; and the artificially customized heavy medium particles are used to push away the minerals with a density higher than or lower than the density of the heavy medium particles to form a relatively wide intermediate density film flow mineral zone, thereby facilitating interception and obtaining a mineral separation effect with high grade and high recovery rate.

[0056] S4: Collecting the mineral A, the mineral B and the mineral C into a magnetic separator with a magnetic field strength of 0.5T to remove the medium, and obtaining the gravity separation copper concentrate and the tailings without the heavy medium, wherein the grade of the gravity separation copper concentrate is 2.22%, and the gravity separation copper concentrate can be directly sent to the flotation operation for further enrichment into a copper concentrate product.

[0057] Figure 3 The data table after removing the medium shows that the use of the heavy medium in the spiral chute for mineral separation can improve the copper production rate, the addition of the artificial heavy medium mineral can separate the target mineral and the tailings impurities by a wide distance for convenient interception of the pure target mineral, the target mineral zone and the tailings zone are separated by the wide heavy medium zone, and the use of the magnetic property of the heavy medium can effectively remove the impurities in the oxidized copper ore, which can equivalent to the copper concentrate production rate of 8 times of the flotation process, and replace 90% of the chemical flotation process, thereby greatly reducing the chemical waste residue and wastewater discharge pollution.

[0058] The above embodiments are only preferred embodiments of the present application, and of course cannot limit the scope of the present application, and any equivalent changes made according to the claims of the present application still belong to the scope of the present application.

Claims

1. A beneficiation method for screening separation of target ore and gangue tailings in a mineral charge, characterized by, Includes the following steps: S1. Add a heavy medium with preset characteristics that are significantly different from the target ore and with a density between that of the target ore and the main gangue tailings to the target ore raw material to obtain a mixed ore material; S2. After adding water to the mixed ore obtained in S1 to make slurry, it is sent to the spiral mineral processing sluice. Under the screening of the mineral processing sluice, the target ore, heavy medium, gangue tailings flow zone will be formed in sequence. S3. Based on the separation of the target ore and gangue tailings material flow zones by the heavy medium material flow zone, the gangue tailings are separated from the ore at the discharge port of the spiral chute, thereby achieving the separation of gangue tailings and target ore. S4. Utilize the preset characteristics of heavy media to separate the target ore and heavy media, thus completing the preliminary mineral processing process; The target mineral raw material is one of the following: copper oxide ore, phosphate rock ore, spodumene ore, fluorite ore, and calcite ore. The spiral ore beneficiation sluice includes an intermediate column and a sluice body installed on the intermediate column. The sluice body is provided with screening ridges, which divide the sluice body into three parts with decreasing smoothness from the inside to the outside. The screening ridges in the middle part are inclined in the opposite direction to the screening ridges on both sides, and the middle part accounts for one-third to one-half of the total area.

2. The beneficiation method according to claim 1, characterized in that, In step S3, the spiral chute is provided with at least two discharge ports, one of which is used to collect the gangue tailings flow, and at least one of the remaining discharge ports is used to collect the target ore flow and the heavy medium flow, or; One outlet is used to collect the gangue tailings flow, and at least one of the remaining outlets is used to collect the target ore flow, while the other is used to collect the heavy medium flow.

3. The beneficiation method according to claim 1, characterized in that, The target ore is a type of non-magnetic ore, and the heavy medium is magnetic. In step S4, the target ore and the heavy medium are separated by a magnetic separation mechanism by utilizing the magnetic difference between the target ore and the gangue tailings.

4. The beneficiation method according to claim 3, characterized in that, The target ore is copper ore. Before step S1, the process includes first crushing and grinding the copper ore into powder with a liberation degree of more than 90%, and then using a magnetic separator to separate the magnetic minerals from the target ore raw material.

5. The beneficiation method according to claim 4, characterized in that, In step S4, at the discharge port at the bottom of the spiral chute, the target ore stream is passed through a magnetic separator to remove the magnetic heavy medium.

6. The beneficiation method according to claim 1, characterized in that, The target ore is a type of non-conductive ore, and the heavy medium is designed to be conductive. In step S4, the target ore and the heavy medium are separated by a conventional electrostatic separation method by utilizing the difference in conductivity between the target ore and the gangue tailings.

7. The beneficiation method of claim 1, wherein, The particle size of the heavy medium is larger than that of the target ore. In step S4, the target ore and the heavy medium are separated by passing the ore through a conventional screen, taking advantage of the difference in particle size between the target ore and the gangue tailings.

8. The beneficiation method of claim 1, wherein, It also includes step S5: further separating and recovering the heavy media entrained in the gangue tailings initially obtained in step S3.

9. The beneficiation method according to any one of claims 1 to 8, characterized in that, In step S1, the mass ratio of the added heavy medium to the target mineral raw material is 0.4-1.0:1.0.

Images