JP2018183726A - Trommel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trommel which maintains sieving performance of nickel raw material ore used in an HPAL plant, and can extend its life.SOLUTION: A trommel 100 that is connected to a drum provided on a drum washer and is provided with a cylindrical screen rotatable around a shaft core, where a screen 110 includes a lattice-shaped metal grating 111 so as to extend in a shaft core direction from a connection part with the drum, and a lattice-shaped resin screen 112 is provided on the extended tip of the metal grating 111 so as to extend in the shaft core direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a trommel, and more particularly to a trommel attached to a drum washer for sieving nickel raw material ore used in an HPAL plant.

  In recent years, high pressure acid leaching using sulfuric acid has attracted attention as a method for hydrometallizing nickel oxide ore. Unlike the conventional dry smelting method, which is a conventional nickel oxide ore smelting method, this method does not include dry processes such as reduction and drying processes, and is a consistent wet process. This is advantageous. In addition, there is an advantage that a sulfide containing nickel (hereinafter, also referred to as “nickel sulfide”) whose nickel quality is improved to about 50 mass% can be obtained.

  In an HPAL plant that uses low-grade nickel ore, nickel raw material ore as a raw material is transported and supplied from the mine. This contains a large particle size ore, which becomes an obstacle when pumped with a pump or the like. Moreover, since the nickel grade of the large particle size ore is low and the leaching is only on the surface of the ore, the leaching rate needs to be removed low. Therefore, a cleaning and sieving device is installed in the nickel raw material adjustment step of adjusting the nickel raw material ore in the HPAL plant in order to remove the large particle size ore.

  As the washing and sieving device, a drum washer composed of a drum and a trommel for removing large particle size ores is used. Trommel is equipped with a cylindrical sieve mesh that is installed sideways (the shaft core is horizontal or near horizontal), and the material to be treated put into the sieve mesh by rotating the sieve mesh around the shaft core. It is an apparatus that performs classification processing of objects (processing that separates workpieces of various sizes according to their sizes). One application of such trommel is to perform nickel oxide ore classification treatment.

  For example, in order to prevent the efficiency of crushing and classification when adjusting nickel raw material ore from being significantly reduced, predetermined requirements are set on the same circumference of the cross section perpendicular to the trommel rotation axis on the inner surface of the trommel. A satisfactory projection has been proposed (see Patent Document 1).

JP 2009-173967 A

  However, when the above-described Trommel described in Patent Document 1 is used in an HPAL plant, the large particle size ore contained in the ore slurry is lifted by discharging or rotating from the drum, and falls in the middle of rotation. Due to the impact of the trommel, the screen of the trommel will be worn or damaged, requiring repair during operation. In-service repairs can affect the availability of downstream equipment and can reduce production efficiency.

  In order to avoid such a situation, a general Trommel screen using expanded metal has been used. However, if damage is confirmed during regular operation, the equipment is shut down each time. It was necessary to stop frequently because the service life was short.

  Therefore, the present invention has been proposed in view of such circumstances, and provides a new and improved trommel capable of extending the life while maintaining the sieving performance of nickel raw material ore. For the purpose.

  That is, in order to achieve the above object, according to one aspect of the present invention, there is provided a trommel that is connected to a drum provided in a drum washer, and is provided with a cylindrical screen that can rotate around an axis. A grid-like metal grating extending from the connecting portion with the drum along the axial direction, and extending along the axial direction at a tip of the metal grating. Thus, a grid-like resin screen is provided.

  In one aspect of the present invention, it is preferable that the metal grating extends to a range of 0.25 to 0.5 times the length of the screen in the axial direction.

  In one aspect of the present invention, a punching metal is further provided along the outer peripheral surface of the resin screen, and the opening of the punching metal is preferably larger than the opening of the resin screen.

  In one aspect of the present invention, the thickness of the metal grating is preferably at least 5 mm.

  In one aspect of the present invention, the metal grating may be composed of a plurality of components.

  In one aspect of the present invention, the metal grating is preferably made of carbon steel or stainless steel.

  In one aspect of the present invention, the resin screen is preferably formed of a polyurethane resin.

  In one aspect of the invention, the drum washer may be used to screen nickel raw ore in a hydrometallurgical plant.

  According to the present invention, the sieving performance of the nickel raw material ore used in the HPAL plant can be maintained and the life can be extended.

It is process drawing of the hydrometallurgical method by the high pressure acid leaching method of nickel oxide ore. It is a schematic explanatory drawing of a drum washer. It is a schematic explanatory drawing of the trommel which concerns on 1st Embodiment. It is the schematic sectional drawing which provided the punching metal on the outer side of the resin screen with which the trommel which concerns on 1st Embodiment is equipped. It is a schematic explanatory drawing of the trommel which concerns on 2nd Embodiment. 1 is a schematic explanatory diagram of a trommel based on Example 1. FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

[1. Overview]
The hydrometallurgical process of nickel oxide ore is a smelting process in which nickel is leached and recovered from nickel oxide ore using, for example, a high-pressure acid leaching method (HPAL method).

  FIG. 1 is a process diagram of a hydrometallurgical method using high pressure acid leaching of nickel oxide ore. As shown in FIG. 1, the hydrometallurgy process of nickel oxide ore includes an ore slurrying step S1 for slurrying nickel oxide ore, and an ore slurry concentration step for concentrating ore components by removing moisture contained in the ore slurry. S2 and a leaching step S3 in which sulfuric acid is added to the produced ore slurry and leaching is performed under high temperature and high pressure, and the residue (leaching residue) is separated while the obtained leaching slurry is washed in multiple stages, and impurity elements together with nickel A solid-liquid separation step S4 for obtaining a leachate containing lysate, and adjusting the pH of the leachate by adding limestone as a neutralizing agent to the leachate to separate neutralized starch containing impurity elements, and a neutralized final solution containing nickel And a neutralization step S5 to be obtained, and a sulfurization step S6 for generating a sulfide containing nickel (nickel sulfide) by adding a sulfurizing agent to the neutralized final solution.

  Furthermore, this hydrometallurgy method has a final neutralization step S7 for recovering and detoxifying the leaching residue separated in the solid-liquid separation step S4 and the poor liquid discharged in the sulfurization step S6. This final neutralization step S7 includes a first-stage neutralization treatment (first final neutralization step) using limestone as a neutralizing agent and a second-stage neutralization treatment using slaked lime as a neutralizing agent (first neutralization step). A stepwise neutralization process comprising the second final neutralization step) is performed. By performing such a two-step neutralization treatment, a neutralization treatment residue is generated and stored in a tailing dam (tailing residue).

  In the HPAL plant, a cleaning device is installed to remove the large particle size ore in the process of obtaining the ore slurry from the nickel raw material ore in the ore slurrying step S1. The cleaning device has a function of selecting nickel raw material ore because the ore is acid leached in the leaching step S3 described above. This washing apparatus is composed of a drum washer (drum type washing machine) and a sieving machine. The drum washer has a function of improving the nickel quality in the ore slurry by washing the nickel raw material ore with water.

  FIG. 2 is a schematic explanatory diagram of the drum washer. As shown in FIG. 2, the drum washer 1 includes a drum 10 and a trommel 20, and a recovery blade 11 is provided on the connection side of the drum 10 with the trommel 20. The drum 10 has a function of pulverizing, repulping (unraveling) nickel oxide ore into an ore slurry S. The collection blade 11 has a function of scooping up the ore contained in the ore slurry S from the drum 10. The trommel 20 has a function of sieving the ore contained in the ore slurry S.

  In the drum washer 1, water and nickel oxide ore are supplied from an inlet (not shown) provided on the inlet side (upstream side) of the drum 10. The slurry is made into a slurry and sent to the trommel 20 which is a large classifier, and the ore having a particle diameter of 25 mm or more contained in the ore slurry S is removed by the screen of the trommel 20. Further, the ore having a particle size of 1.4 mm or more contained in the ore slurry S that has passed through the screen is removed by a sieving machine disposed under the screen of the trommel 20.

  Therefore, a large classifier called Trommel 20 is installed on the outlet side (downstream side) of the drum 10 in order to screen the ore slurry S and the large particle size ore. The screen of the trommel 20 is made of an expanded metal, a wire mesh, or a resin screen having a cylindrical shape or a conical shape, and the trommel 20 is connected to the drum 10 so as to rotate together with the drum 10 and sieve the charged material. It has a configuration that can be separated.

  The ore slurry S delivered from the drum 10 overflows from a weir (not shown) installed near the connecting portion of the drum 10, and the ore contained in the ore slurry S is scooped up by the recovery blades 11 provided in the drum 10. And transported to the trommel 20. Here, since the ore is lifted up from the system of the drum 10 by providing the recovery blades 11 on the drum 10, the ore contained in the ore slurry is transferred from the drum 10 to the trommel 20 without any delay. As a result, the ore content is stabilized and an ore slurry is obtained, and the large particle size ore is less likely to stay in the drum 10, so that the wear of the drum 10 itself can be suppressed and the energy required for driving the drum 10 is also reduced. It is reduced.

  However, when the large particle size ore contained in the ore slurry S is transferred to the trommel 20 by the recovery blade 11, the large particle size ore falls in the form of the trommel 20 screen, and the impact is very large. As a result, the wear and damage of the screen becomes remarkable.

  Here, when the screen of the trommel 20 is broken, the large particle size ore is brought into the subsequent sieving machine, the load applied to the sieving machine is increased, and the sieving machine is easily broken. If the sieving machine breaks down, the narrow part of the pump or valve will be clogged with large-size ore, blocking the ore slurry flow path and forced to shut down the equipment for a long time to remove the clogging. Is done. In order to prevent damage to the sieving machine and clogging of the flow path, if the Trommel 20 screen is worn or damaged, the equipment is shut down and the screen is repaired even during operation of the HPAL plant. It was necessary to replace the equipment and replaced the equipment, which was a factor that reduced the operating rate of the equipment.

  In order to suppress screen wear and breakage, for example, a thick metal grating can be provided on all screens. However, at the price of securing the strength of the screen, the opening area for sieving is insufficient, and the ore slurry as a raw material is excessively discharged out of the system of the trommel 20 and the weight of the equipment also increases. And driving becomes difficult. On the other hand, when all the screens are made of resin, they have a certain level of impact resistance and wear resistance, but the strength of the resin screen itself is insufficient, and the resin screen is in operation. Openings gradually spread and ores larger than the desired particle size cannot be excluded.

  Therefore, in order to maintain the sieving performance of the screen of the trommel 20 attached to the drum washer 1 used when sieving the nickel raw material ore used in the HPAL plant, the inventor has a connecting portion with the drum 10. The present invention was completed by finding that the service life of the trommel 20 can be extended by providing a grid-like metal grating around the periphery.

[2. Trommel]
Next, the trommel according to the present embodiment will be described with reference to the drawings.

[2-1. First Embodiment]
FIG. 3 is a schematic explanatory diagram of the trommel according to the first embodiment. As shown in FIG. 3, the trommel 100 according to the first embodiment is provided with a conical (conical frustum cylindrical) screen 110 that is rotatable about an axis. The screen 110 has a function of sieving the ore transferred from the drum into a desired particle size. Since the screen 110 has a conical shape, the large particle size ore contained in the ore slurry transferred from the drum provided in the drum washer by the recovery blade is rolled on the screen 110 along a slope. Hereinafter, each component will be described.

  In the first embodiment, the screen 110 includes a grid-like metal grating 111 so as to extend along the axial direction from the connecting portion with the drum, and at the tip where the metal grating 111 extends, A grid-like resin screen 112 is provided so as to extend along the axial direction. The metal grating 111 may have an integrated configuration or may have a configuration divided into a plurality of components. This fractionated structure means a structure composed of a plurality of metal grating parts.

  Thereby, in 1st Embodiment, even if the large particle size ore contained in the ore slurry transferred by the recovery blade from the drum falls directly on the screen 110, the first hit point is impact resistant. Since it becomes the area | region of the high metal grating 111, the abrasion and damage by a direct fall are suppressed. And even if this large grain size ore gives an impact to the metallic grating 111 and then rolls further along the slope to the resin screen 112, it is weaker than the initial impact, so it is made of resin compared to the conventional screen. The screen 112 is prevented from being worn or damaged. In this way, the good sieving performance of the grid-like metal grating 111 and the grid-like resin screen 112 can be maintained. Therefore, the operation in the HPAL plant can be stably performed for a long period of time without stopping for repair or replacement of the screen 110.

  It is preferable that the metal grating 111 extends to a range of 0.25 to 0.5 times the length of the screen 110 in the axial direction, in a range of 0.3 to 0.4 times. More preferably it is. By making such a range, the falling point of the large particle size ore transferred from the drum is an area provided with the metal grating 111 while suppressing the energy required for driving the trommel 100, so that the impact caused by the collision is reduced. Can also withstand. For this reason, it is possible to maintain the function of sieving the ore of the trommel 100 without damaging the trommel 100 in a short time during the operation of the HPAL plant, and it is more reliable to extend the life of the trommel 100 itself. .

  When the metal grating 111 extends only to less than 0.3 times, it is considered that the large particle size ore transferred from the drum jumps over the metal grating 111 and falls to the resin screen 112. At that time, the trommel 100 may be damaged in a short time. In particular, when the metal grating 111 extends only to less than 0.25 times, after the large-sized ores are piled up on top of each other in addition to the movement of the large-sized ores being swept up or splashed off There is also a risk of falling onto the resin screen 112 due to the falling movement. On the other hand, when the metal grating 111 extends more than 0.4 times, the range of the metal grating 111 on the screen 110 becomes large and requires a lot of energy to rotate. In particular, when the metal grating 111 extends more than 0.5 times, if the shape of the trommel 100 spreads as it moves away from the drum side (a trumpet shape), it is at a position larger than the average radius of the trommel 100 ( The metal grating 111 is heavier than the resin property. As a result, a lot of energy is required to rotate the trommel 100 in proportion to the moment of inertia proportional to the square of the radius and further proportional to the density.

  The metal grating 111 is not particularly limited as long as it is formed of a metal, an alloy, or the like, but is preferably formed of carbon steel, stainless steel, or the like that is excellent in water resistance and impact resistance.

  The thickness of the metallic grating 111 is preferably at least 5 mm. By setting the thickness to 5 mm or more, the metal grating 111 becomes strong and can extend its life, and it becomes easy to visually check the progress of wear. When this thickness is less than 5 mm, when the large particle size ore contained in the ore slurry falls and collides, there is a possibility that the mesh opening of the lattice is expanded beyond a desired range due to the impact.

  Further, as the lattice-shaped metal grating 111, a grating having a square hole is used, but the grating is not limited thereto, and a hexagonal hole, a triangular hole, or a round hole is provided instead of the square hole. Even the metal grating 111 can be used without any problem.

  In the first embodiment, reinforcing frames 120 a and 120 b are attached to reinforce the screen 110. Specifically, the reinforcing frame 120 a is attached so as to connect the metal grating 111 and the resin screen 112. A reinforcing frame 120b is attached to the outer peripheral surface of the screen 110 along the longitudinal direction. Further, a reinforcing ring 121a is attached to the base end (end on the drum side) of the screen 110, and a reinforcing ring 121b is attached to the front end (end opposite to the drum) of the screen 110.

  The metal grating 111 is pre-configured to be divided into a plurality of grating parts. If the metal grating 111 is damaged or worn during operation at the HPAL plant, the entire metal grating 111 is replaced. Instead, it is only necessary to replace the part corresponding to the damaged area. For this reason, it is not necessary to replace the entire surface as in the case of a conventional wire mesh screen, and the cost and labor are minimized.

  The resin screen 112 is not particularly limited, but is preferably formed of one or more of a polyurethane resin, a polyester resin, a nylon resin, and a polyamide resin, and in particular, formed of a polyurethane resin excellent in impact from the outside. More preferably.

  Further, the thickness of the resin screen 112 should be such that there is no step at the boundary with the metal grating 111. If there is a step, the thickness should be smaller than the diameter of the ore particles. . In particular, it is appropriate to set the thickness to a level difference of 25 mm or less. For example, when the level difference exceeds 25 mm, the resin screen 112 is renewed (repositioned), or the resin screen 112 or the metal grating 111 is attached. It is desirable to change the step so that the step becomes 25 mm or less.

  In order to reduce the impact generated when ore moves from the metal grating 111 to the resin screen 112, it is desirable to attach the metal grating 111 and the resin screen 112 at equal angles.

  In the first embodiment, the resin screen 112 is preferably provided with a reinforcing material on the resin screen 112. FIG. 4 is a schematic cross-sectional view in which a punching metal is provided on the outer side of the resin screen provided in the trommel according to the first embodiment. In the first embodiment, a punching metal 113 is provided outside the resin screen 112 along the outer peripheral surface of the resin screen 112 as shown in FIG. Further, the opening W2 of the punching metal 113 is larger than the opening W1 of the resin screen 112 in order to ensure the function of sieving the ore as the screen 110.

  Thereby, after the large particle size ore transferred from the drum gives the impact due to the collision to the metal grating 111, even if the large particle size ore rolled along the inclination gives the impact due to the collision to the resin screen 112, Since the impact is transmitted not only to the resin screen 112 but also to the punching metal 113, the punching metal 113 can reinforce the resin screen 112, and the resin screen 112 can withstand an external impact. Thus, in the punching metal 113, the resin screen 112 functions as a reinforcing material. Therefore, the service life of the trommel 100 can be more reliably maintained, and further, the function of sieving the ore of the trommel 100 can be maintained.

[2-2. Second Embodiment]
FIG. 5 is a schematic explanatory diagram of a trommel according to the second embodiment. As shown in FIG. 5, the trommel 200 according to the second embodiment is provided with a cylindrical screen 210 that is rotatable about an axis, and reinforcing frames 220 a and 220 b and Reinforcing rings 221a and 221b are attached. Hereinafter, each component will be described. In addition, the description which overlaps with 1st Embodiment is omitted.

  In the second embodiment, the screen 210 is provided with a grid-like metal grating 211 extending from the connecting portion with the drum along the axial direction, and the tip of the metal grating 211 is extended to A grid-like resin screen 212 is provided so as to extend along the axial direction.

  When the trommel 200 is used as a drum washer, the cylindrical screen 210 is connected to the outlet side of the drum in a lateral direction, and is at a predetermined angle (for example, 1 ° to 20 ° with respect to the horizontal direction) together with the drum. ). At this time, the large particle size ore contained in the ore slurry transferred by scraping with a recovery blade from the drum provided in the drum washer rolls and discharges on the screen 210 along an inclination.

[3. Summary]
As described above, the trommel according to the first embodiment and the second embodiment is connected to the drum provided in the drum washer, and is provided with the cylindrical screen that can rotate around the axis. The screen is provided with a grid-like metal grating so as to extend along the axial direction from the connecting portion with the drum, and extends along the axial direction at the tip where the metal grating is extended. Thus, a grid-like resin screen is provided.

  Thus, by dropping the large particle size ore contained in the ore slurry by the recovery blade provided in the drum, the falling point of the large particle size ore transferred from the drum to the trommel is the region where the metal grating is provided. As a result, the trommel screen can withstand strong impacts. For this reason, the lifetime of the trommel itself can be extended without damaging the trommel screen in a short period of time during operation of the HPAL plant. As a result, it is not necessary to frequently shut down and repair or replace the trommel screen. Further, a drum washer having a drum connected to the trommel is optimal for screening nickel raw material ore in a hydrometallurgical plant because it can operate the HPAL plant efficiently with less frequent stoppages.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited to these Examples or a comparative example.

  In a HPAL (high pressure acid leaching process) plant, the nickel oxide ore was slurried as a pretreatment for acid leaching of nickel oxide ore using a drum washer with a trommel connected to the drum under the conditions of Example 1 below. And performed under the conditions of Comparative Example 1 below.

Example 1
FIG. 6 is a schematic explanatory view of a trommel based on the first embodiment. In Example 1, as shown in FIG. 6, the base end (the end on the drum side) of the screen 310 of the conical trommel 300 on which the ore discharged from the drum unit of the drum washer first falls. The first row screen 311 on the side is also a metal grating (width 800 mm) with flat steel (horizontal length 24 mm × thickness 5.0 mm) assembled in a lattice shape in consideration of impact resistance. X horizontal length 1250 mm x thickness 25 mm). The second row screen 312 and the third row screen 313 are provided with a 30 mm thick urethane screen (opening 25 mm), and a perforated iron plate with a thickness of 6 mm is further provided along the outer peripheral surface of the urethane screen for the purpose of reinforcement. A double-structured screen was installed. Further, reinforcing frames 320a and 320b and reinforcing rings 321a and 321b were mounted on the screen, respectively. The first row screen 311 to the third row screen 313 are arranged at equal intervals. The urethane screen refers to a screen made of polyurethane.

  As a result of operating the HPAL plant, as shown in Table 1, the time required for repair and the time required for replacement of the first row screen 311 were one year after the start of use. Further, the repair required time for the second row screen 312 and the third row screen 313 was 4 to 6 months from the start of use, and the replacement time was 6 to 8 months from the start of use.

(Comparative Example 1)
In Comparative Example 1, the operation was performed in the same manner as in Example 1 except that the first-row screen to the third-row screen were changed to a urethane screen having a thickness of 30 mm (aperture 25 mm).

  As a result of operation, as shown in Table 2, the time required for repairing the screen in the first row was 1 to 2 months after the start of use, and the time required for replacement was 2 to 4 months after the start of use. Moreover, the repair required time of the 2nd row screen and the 3rd row screen was 2 to 4 months from the start of use, and the replacement time was 4 to 6 months from the start of use.

(Consideration based on Examples)
Comparing Tables 1 and 2, in Example 1, the frequency of screen repair and replacement was less than that in Comparative Example 1, that is, the trommel can be used for a long time. As a result, the operating rate of this facility based on Example 1 was improved, and stable operation became possible. Also, in the operation after the implementation, only ores having a size of 25 mm or less were observed on the sieve, and it was confirmed that ore slurry containing ores having a particle diameter narrower than the screen opening could be recovered. It was.

  As described above, the metal grating was provided so as to extend along the axis from the connecting portion (the base end of the screen) with the drum used in Example 1, so that it was used in Comparative Example 1. It was confirmed that the time required for repair and the time required for replacement were longer than those of Trommel, which had a urethane screen on the entire screen. That is, it is considered that the trommel used in Example 1 was able to extend its life in the operation of the HPAL plant by providing the metal grating on the inlet side of the trommel.

1 drum washer, 10 drum, 11 recovery blade, 20 trommel, 100 trommel, 110 screen, 111 metal grating, 112 resin screen, 113 punching metal, 120a, 120b reinforcing frame, 121a, 121b reinforcing ring, 200 trommel, 210 Screen, 211 Metal grating, 212 Resin screen, 220a, 220b Reinforcement frame, 221a, 221b Reinforcement ring, 300 Trommel, 310 screen, 311 First row screen, 312 Second row screen, 313 Third row screen 320a, 320b Reinforcement frame, 321a, 321b Reinforcement ring, S Ore slurry

Claims (8)

A trommel that is connected to a drum provided in a drum washer, and is provided with a cylindrical screen that can rotate around an axis,
The screen is provided with a grid-like metal grating so as to extend from the connecting portion with the drum along the axial direction.
A trommel characterized in that a lattice-shaped resin screen is provided at the tip of the metal grating extending so as to extend along the axial direction.   The trommel according to claim 1, wherein the metallic grating extends to a range of 0.25 to 0.5 times the length of the screen in the axial direction. A punching metal is further provided along the outer peripheral surface of the resin screen,
The trommel according to claim 1 or 2, wherein an opening of the punching metal is larger than an opening of the resin screen.   The trommel according to any one of claims 1 to 3, wherein a thickness of the metallic grating is at least 5 mm or more.   The trommel according to any one of claims 1 to 4, wherein the metal grating has a plurality of components.   The trommel according to any one of claims 1 to 5, wherein the metallic grating is made of carbon steel or stainless steel.   The trommel according to any one of claims 1 to 6, wherein the resin screen is made of a polyurethane resin.   The trommel according to any one of claims 1 to 7, wherein the drum washer is used for sieving nickel raw material ore in a hydrometallurgical plant.

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