Transportation status display system and raw ore pre-processing equipment equipped with the same

Abstract

To provide a conveying situation display system capable of quickly and surely notifying a field worker of a situation thereof, when clogging is generated inside a hopper and a device trouble is generated due to a property of an article to be conveyed, a human error or the like.SOLUTION: According to a belt conveyor 6 for conveying raw material ore such as, for example, nickel oxide ore or the like having a moisture content of 20 mass% or more and 50 mass% or less, that is supplied from a lower end part of a hopper 5; provided are a detector 10 that outputs a signal by detecting this situation at a time when it is interrupted to convey the raw material ore, and a display part 20 comprising a first pilot lamp that is lit by the signal output from the detector 10 and a second pilot lamp for displaying an operation situation of the belt conveyor 6.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a transportation status display system that displays the transportation status in a transportation facility for raw ore that is processed by a method such as hydrometallurgy for nickel oxide ore, and to a raw ore pretreatment facility equipped with the same. [Background technology]

[0002] As a hydrometallurgical method for nickel oxide ore, a high pressure acid leaching method using sulfuric acid, also called HPAL (High Pressure Acid Leaching) method, is known. This hydrometallurgical method is a process in which the treatment is consistently performed in a wet manner from the raw material nickel oxide ore to the production of the product nickel-cobalt mixed sulfide, and is therefore more advantageous in terms of energy and cost than the conventional pyrometallurgical method for smelting nickel oxide ore, which has a reduction process and a drying process. In addition, the hydrometallurgical method has the advantage that the nickel-cobalt mixed sulfide with a nickel content of about 50 mass% can be efficiently produced from low-grade nickel ore with a nickel content of about 1%.

[0003] In the hydrometallurgical plant where the treatment is performed by the HPAL method, in order to increase the reaction efficiency during the acid leaching treatment of the raw ore consisting of nickel oxide ore, the raw ore is introduced into a pretreatment facility in which a plurality of devices such as a crusher and a sieving machine are continuously connected via a conveying facility such as a belt conveyor, thereby pretreating the raw ore to make the particle size finer in stages. In this case, if the supply of raw ore to each device is temporarily interrupted or, conversely, if it is excessively supplied and becomes overloaded, the pretreated raw ore cannot be stably supplied to the downstream processing step, so that the productivity decreases and the quality of the product decreases. In order to prevent such problems, a technique has been proposed in which a hopper for feeding the material to be conveyed is provided in front of the belt conveyor to measure the level of the powder and granular material in the hopper, or a detector is provided to detect that the material to be conveyed is being conveyed on the belt conveyor.

[0004] For example, Patent Document 1 discloses a technique in which a bypass pipe is provided on the wall of a charging hopper of a conveying facility having a structure in which a charging hopper is provided between two consecutive belt conveyors for transporting pig iron-making raw materials, the bypass pipe extends obliquely downward from the upper limit of the capacity of the charging hopper, and a tray biased upward by a spring is provided so as to be movable in the vertical direction directly below the lower end outlet of the bypass pipe. As a result, when pig iron-making raw materials are excessively supplied beyond the capacity of the charging hopper, the excess pig iron-making raw materials are received in the tray via the bypass pipe, and the tray moves downward by gravity. As a result, a limit switch striker provided on the tray activates a limit switch, making it possible to stop the drive motor of the belt conveyor.

[0005] Furthermore, Patent Document 2 discloses a technology in which a rotating detection arm is provided in the center of the width of the belt conveyor, and a sensor is used to detect whether the detection arm is tilted in the conveying direction by the object, thereby detecting that an object is being conveyed on the belt conveyor. Patent Document 3 discloses a technology in which a light-projecting device and a light-receiving device are provided on both sides of the width of the belt conveyor, and whether an object is being conveyed on the belt conveyor is detected based on whether the object blocks a light beam that travels straight between these devices. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 57-181718 [Patent Document 2] Japanese Patent Publication No. 54-027167 [Patent Document 3] Japanese Utility Model Application Publication No. 60-193489 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when handling moist and sticky ore, such as raw ore stored outdoors in a stockpile, the technology of Patent Document 1 may cause the bypass pipe to be blocked by sticky ore and may not function properly. In addition, moist ore is difficult to spread evenly on the surface of the conveyor, so if the ore is unevenly distributed at the ends in the width direction, it will not be possible to detect it with the detection arm of Patent Document 2. It is considered that the technology of Patent Document 3 can detect moist ore, but conversely, when dry ore with little moisture is transported, dust that is blown up from the ore during transportation may adhere to the surfaces of the light projector and light receiver, making accurate detection impossible.

[0008] The present invention has been made in consideration of the problems associated with the conventional conveying equipment described above, and has an object to provide a conveying status display system that can quickly and reliably inform on-site workers of a situation when a blockage occurs in a hopper or an equipment trouble occurs due to the properties of the conveyed material, human error, or the like in a conveying equipment for raw ore such as nickel oxide ore being processed in a hydrometallurgical plant. [Means for solving the problem]

[0009] In order to achieve the above object, the raw ore conveyance status display system according to the present invention comprises a detector that detects a break in the conveyance of raw ore on a belt conveyor that conveys raw ore supplied from a lower end of a hopper and outputs a signal, and a display unit having a first indicator light that is turned on by the signal output from the detector and a second indicator light that displays the operating status of the belt conveyor. The detector is composed of a rod-shaped portion extending across the belt conveyor at a position above the belt conveyor and immediately downstream of the lower end of the hopper, a support portion rotatably supporting the rod-shaped portion, a plurality of swinging bodies hanging down from the rod-shaped portion and capable of swinging freely, and a sensor portion which detects that the inclination angle of the swinging body when it comes into contact with the raw material ore being transported by the belt conveyor becomes less than a predetermined angle and outputs a signal, and the detector further includes a stopper formed of an elastic body which prevents the swinging body from swinging in the opposite direction to the transport direction of the belt conveyor. It is characterized by: Effect of the Invention

[0010] According to the present invention, in a conveying facility for raw ore such as nickel oxide ore, when a blockage occurs in a hopper or an equipment trouble occurs due to a human error such as a delay in the timing of feeding the ore by a wheel loader or the properties of the conveyed material, it is possible to promptly and reliably inform an on-site worker of the situation. This makes it possible to minimize the influence of problems such as a decrease in the amount of raw ore fed to the downstream processing step. In addition, since it is no longer necessary to have a worker who monitors the condition inside the hopper, which was previously necessary, it is possible to reduce costs. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a block flow diagram of a pretreatment process of nickel oxide ore in which a pretreatment facility equipped with a raw ore transport status display system according to the present invention is suitably used. [Diagram 2] 1 is a schematic vertical cross-sectional view of a pretreatment facility equipped with a transport status display system according to an embodiment of the present invention. [Diagram 3] 3 is a side view showing a detector constituting the transport status display system of FIG. 2. [Figure 4] 4 is a cross-sectional view of the detector of FIG. 3 as viewed from the direction of the arrows along line IV-IV. [Diagram 5] 3A and 3B are diagrams showing a state in which the first display unit in the transport status display system of FIG. 2 is turned off and turned on to inform the wheel loader operator of the need to add raw ore. FIG. [Figure 6] FIG. 13 is a diagram showing a state in which the conveyor belt operation indicator light is on and the hopper supervisor is giving a signal to permit loading, in a method for displaying the transport status of a comparative example of the present invention, to inform the wheel loader operator of the need for loading raw ore ore ore to be loaded, (a), and a state in which the conveyor belt stop indicator light is on and the hopper supervisor is giving a signal to prohibit loading, (b). [Figure 7]7A and 7B are diagrams showing how the belt conveyor stops due to (a) a misidentification of the amount of ore in the hopper by the hopper monitor and (b) a lack of communication between the hopper monitor and the wheel loader operator in the transport status display method shown in Fig. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the transport status display system of the present invention will be described with reference to the drawings. The transport status display system of the embodiment of the present invention is suitably adopted in a transport facility for nickel oxide ore used as a raw material in a hydrometallurgical plant that performs processing by the HPAL method. The HPAL method generally includes a leaching process in which a raw material ore made of nickel oxide ore is charged into an autoclave together with sulfuric acid and acid leaching treatment is performed under high temperature and high pressure, a neutralization process in which the obtained leachate containing nickel and cobalt is neutralized to obtain a neutralized end liquid from which impurity elements contained in the leachate have been removed, a liquid purification process in which a sulfurizing agent such as hydrogen sulfide gas is added to the neutralized end liquid under a slightly pressurized atmosphere to obtain a nickel recovery mother liquor from which zinc has been removed, and a sulfurization process in which a sulfurizing agent such as hydrogen sulfide gas is added to the nickel recovery mother liquor under a pressurized atmosphere to produce a nickel-cobalt mixed sulfide.

[0013] In the above hydrometallurgical plant, the raw material ore used as the raw material is crushed and classified to adjust the particle size to a fine size in order to increase the reaction efficiency during the acid leaching treatment, and then charged into an autoclave. Specifically, as shown in Fig. 1, nickel oxide ore mined from a mine is first loaded onto a coarse screen with a mesh size of 300 mm, for example, by a wheel loader in a coarse particle removal process, and coarse particles that cannot pass through the coarse screen with a mesh size of 300 mm (referred to as "over 300 mm"; the same applies below) are removed on the surplus side, while particles that have passed through the screen (referred to as "under 300 mm"; the same applies below) are collected on the surplus side.

[0014] Next, in the first sieving process, the above-mentioned under 300 mm is introduced into a vibrating sieve, where it is sieved through a first screen with a mesh size of, for example, 150 mm, so that the over 150 mm that cannot pass through the first screen is removed on the surplus side, and the under 150 mm that passed through the first screen is collected on the surplus side. Next, in the washing process, the above-mentioned under 150 mm is put into a rotatably supported drum-type rotary crusher called a trommel, where it is crushed by agitation caused by the rotation of the machine, while being washed by spraying washing water on it.

[0015] Next, in the second sieving process, the ore crushed and washed by the drum-type rotary crusher is introduced into a wet vibrating sieve, where it is sieved, for example, by a second screen with a mesh size of 25 mm while being washed with washing water such as industrial water sprayed from above. As a result, ore over 25 mm that cannot pass through the second screen is removed on the sieve top side, and ore under 25 mm that passed through the second screen is collected on the sieve bottom side in the form of an ore slurry.

[0016] Next, in the third sieving step, the ore slurry containing the above-mentioned 25 mm ore under is introduced into a wet vibrating sieve machine, where it is sieved through a third screen with a mesh size of, for example, 1.4 mm while being washed with washing water such as industrial water sprayed from above. As a result, the 1.4 mm ore over that cannot pass through the third screen is removed on the surplus side, and the 1.4 mm ore under that passed through the third screen is collected on the underside in the form of an ore slurry.

[0017] Next, in the gravity settling process, the ore slurry containing the 1.4 mm ore under is introduced together with a coagulant into a thickener consisting of a roughly cylindrical settling tank and a rake that rotates along the bottom of the tank, where it is concentrated by gravity settling and discharged from the bottom as an ore slurry with a slurry concentration of about 40% or more. The ore slurry thus prepared in the pretreatment process is pressurized by a slurry pump and sent to the autoclave for the leaching process described above.

[0018] Next, the first half of the pretreatment equipment in which the coarse particle removing step and the first sieving step of the above pretreatment steps are performed will be described in detail with reference to FIG. The pretreatment equipment in the first half shown in FIG. 2 is composed of a lattice-shaped member or a plurality of parallel rod-shaped members, and is preferably an inclined coarse screen with a mesh size of 300 mm. The static grizzly 1 classifies the raw material nickel oxide ore fed by a wheel loader W to remove coarse materials, a chute 2 that guides the raw material ore that passes through the static grizzly 1 to the equipment below, a vibrating sieve 3 that sieves the raw material ore guided by the chute 2 using a vibrating first screen with a mesh size of, for example, 150 mm, an oversize chute 4 that receives the 150 mm over particles discharged from the upper side of the first screen, a hopper 5 that temporarily stores the 150 mm under particles on the lower side of the first screen, and a belt conveyor 6 that transports the 150 mm under particles discharged from the lower end of the hopper 5 to a drum-type rotary crusher (not shown) in the downstream stage.

[0019] The conveyance status display system according to the embodiment of the present invention is composed of a detector 10 that detects an interruption in the conveyance of raw material ore under 150 mm as the conveyed object conveyed on the belt conveyor 6 and outputs a signal, and a display unit 20 having a first indicator light that is turned on by the signal output from the detector 10 and a second indicator light that displays the operating status of the belt conveyor 6. The conveyance status display system according to the embodiment of the present invention that is composed of the detector 10 and the display unit 20 will be described in detail below.

[0020] In the pretreatment facility in which the conveying status display system according to the embodiment of the present invention is installed, the raw ore is generally made of moist nickel oxide ore having a moisture content of 20% by mass or more and 50% by mass or less, so that clogging may occur in the first screen of the vibrating sieve 3, or a so-called bridge may be formed in the hopper 5, preventing the raw ore from being smoothly discharged from the lower end. In addition, the raw ore temporarily stored in the hopper 5 is preferably in a height range of 500 to 1000 mm from the bottom, but if the height in the hopper 5 exceeds 1000 mm due to excessive charging of the raw ore by a wheel loader, etc., clogging may occur in the hopper 5.

[0021] If clogging occurs in the vibrating sieve 3 or blockage occurs in the hopper 5, the raw ore cannot be transported smoothly on the belt conveyor 6. Therefore, by providing the belt conveyor 6 with a mechanical detector 10 that detects an interruption in the transport of the raw ore on the belt conveyor 6 and outputs an electric signal, it is possible to indirectly notify on-site workers of the occurrence of clogging in the vibrating sieve 3 or blockage in the hopper 5.

[0022] Specifically, as shown in Figures 3 and 4, the detector 10 is composed of a rod-shaped portion 11 extending across the belt conveyor 6 at a position above the belt conveyor 6 and immediately downstream of the lower end of the hopper 5 in the conveying direction, a support portion 12 rotatably supporting both ends of the rod-shaped portion 11, a plurality of freely swinging bodies 13 hanging down from the rod-shaped portion 11, and a sensor portion 14 which detects, based on the rotation angle of the rod-shaped portion 11, that the inclination angle θ of the plurality of swinging bodies 13 when they come into contact with the raw ore transported by the belt conveyor 6 becomes less than a predetermined angle.

[0023] By installing the rod-shaped part 11 with the rocking body 13 as close as possible to the lower end of the hopper 5, any problem in the transport state of the transported object by the belt conveyor 6 can be detected quickly, so that the problem can be prevented from spreading to the subsequent leaching process and thereafter. There is no particular limit to the number of rocking bodies 13, but it is preferable to have a total of three rocking bodies 13, located approximately at the center in the axial direction of the rod-shaped part 11 and on both sides. This allows reliable detection even when the transported object is placed on the belt conveyor 6 and transported unevenly in the width direction. In addition, the overall weight can be reduced, which reduces the impact with the transported object and makes it possible to suppress wear and deformation of the rocking body 13.

[0024] When three oscillating bodies 13 are provided, as shown in Fig. 4, it is preferable to install the oscillating bodies 13 at a distance from each other so that they are located at approximately the center in the width direction of each of the areas A1, A2, and A3 obtained by dividing the effective conveying area A of the belt conveyor 6 into approximately three equal parts in the width direction. This makes it possible to detect the conveyed object more reliably. If the number of oscillating bodies 13 is two or less, it becomes difficult to detect the raw ore if it is conveyed only at the approximately center or only at the end in the width direction of the belt conveyor 6. On the other hand, if the number of oscillating bodies 13 exceeds three, the overall weight becomes heavy, and it is necessary to make the rod-shaped part 11 and the support part 12 have strength commensurate with the weight, which increases the cost.

[0025] The support 12 is provided on the upper surface of the base 8 that projects horizontally from the upper end of the leg 7, and the leg 7 is attached to a frame 6a that supports the rollers of the belt conveyor 6. The base 8 is preferably structured to be vertically movable relative to the leg 7. This can be achieved, for example, by fastening the leg 7 and the base 8 with bolts and nuts, and by making the bolt hole in the leg 7 for inserting the bolt an elongated hole extending vertically or by providing multiple bolts in the vertical direction.

[0026] In this way, by making the base part 8 movable in the vertical direction, when the grain size, characteristics, transport amount, etc. of the objects transported by the belt conveyor 6 change, the height of the base part 8 can be appropriately adjusted to set the inclination angle θ when the oscillator 13 abuts against the objects and tilts to a suitable angle. The inclination angle θ of the oscillator 13 is preferably about 15 to 30°, and more preferably about 20°.

[0027] In FIG. 4, the rod-shaped portion 11 is supported at both ends by two support parts 12, but the present invention is not limited to this, and the rod-shaped portion 11 may be supported by three or more support parts 12. In this case, it is preferable to use a long member such as an L-shaped steel or a C-shaped steel for the base part 8 on which the support part 12 is provided, and to span the base part 8 between a pair of legs 7 on both sides in the width direction of the belt conveyor 6. This can prevent the rod-shaped portion 11 from bending due to the impact when the rocking body 13 comes into contact with the transported object. A pair of side plates 9 are provided at both ends in the width direction of the belt conveyor 6 to prevent the transported object from falling. The area between the pair of side plates 9 is the effective transport area A described above.

[0028] The above-mentioned oscillating body 13 is preferably made of carbon steel so that at least its tip is not easily worn or deformed, since it is constantly in contact with the raw material ore transported by the belt conveyor 6. The shape of the oscillating body 13 may be a strip having a constant width and thickness as shown in FIG. 4, but it is preferable that the shape is gradually narrowed toward the tip. In either case, it is preferable that the tip of the oscillating body 13 is parallel to the conveyor surface of the belt conveyor 6 as shown in FIG. 4. That is, since the conveying roller of the belt conveyor 6 is generally rotatably attached to the frame 6a so that the rotation axis on both sides in the width direction is inclined, it is preferable that the tip of the two on both sides of the three oscillating bodies 13 is inclined along the conveyor surface.

[0029] As shown in FIG. 3, the distance D1 between the tip of the oscillator 13 when it is hanging down without contacting the object to be conveyed and the conveyor surface of the belt conveyor 6 is preferably 30 mm or more and 70 mm or less. If the distance is less than 30 mm, the belt of the belt conveyor 6 may come into contact with the tip of the oscillator 13 and be deformed when it is lifted due to vibration or the like, and if the distance exceeds 70 mm, the raw ore conveyed by the belt conveyor 6 may not be detected. In order to increase the strength, it is preferable to provide the oscillator 13 with a plate-like rib extending in the longitudinal direction. In this case, a rib made of a long plate-like member may be fixed to the center of the oscillator 13 in the width direction by welding so as to have a T-shaped cross section, or the oscillator 13 having the rib may be integrally formed by folding a rectangular plate-like member into a T-shaped cross section.

[0030] As shown in Fig. 3, the rocker 13 tilts to the right side of the drawing as shown by the dashed line when it comes into contact with an object being transported by the belt conveyor 6, and hangs straight down as shown by the solid line when the transport of the object is interrupted. If the rocker 13 tilts to the left side of the drawing beyond the position where it hangs straight down, there is a risk that the rocker 13 will deform or that erroneous detection will occur in the sensor unit 14. To prevent this, it is preferable to provide a stopper 15 so that the rocker 13 does not tilt to the opposite side with respect to the transport direction of the belt conveyor 6. This can increase the reliability of the detector 10. The material of the stopper 15 is not particularly limited, but an elastic material such as rubber is preferable.

[0031] 3, in order to equalize the height of the mountain formed on the conveyor surface by the raw ore discharged from the lower end of the hopper 5, it is preferable to provide a leveling plate 5a at the lower end of the hopper 5 at a position corresponding to at least the downstream side of the belt conveyor 6. In this case, the distance D2 between the lower end of the leveling plate 5a and the conveyor surface of the belt conveyor 6 is preferably 500 mm or more and 540 mm or less. If this distance D2 is less than 500 mm, the wet raw ore is likely to accumulate or be compacted at the lower end of the hopper 5, and the lower end may be blocked. Conversely, if it exceeds 540 mm, the raw ore is likely to be loaded on the belt conveyor 6 in excess of its carrying capacity, and the safety device of the drive motor of the belt conveyor 6 may be activated, causing the belt conveyor 6 to stop.

[0032] There is no particular limitation on the detection method of the sensor unit 14, and a contact or non-contact sensor can be used, and the ON / OFF of the first indicator light of the display unit 20 is controlled by the signal output from this sensor unit 14. For example, when a limit switch is used in the sensor unit 14, a limit switch striker provided at the end of the rod-shaped portion 11 can activate the limit switch or move it away from the limit switch depending on the angle of rotation of the rod-shaped portion 11.

[0033] That is, as shown in Fig. 5(a), when the raw ore is being stably transported by the belt conveyor 6, the oscillator 13 of the detector 10 tilts at an angle θ in the transport direction and the rod-shaped part 11 rotates by the same angle θ, so that the limit switch striker provided on the rod-shaped part 11 is separated from the limit switch, and a state in which no signal is output to the first indicator light of the display part 20 can be maintained. In this case, the first indicator light remains off.

[0034] On the other hand, as shown in Fig. 5(b), when the transport of the raw ore by the belt conveyor 6 is interrupted, the swinging body 13 of the detector 10 hangs straight down, so that the limit switch striker provided on the rod-shaped part 11 can be brought into contact with the limit switch to output a signal to the first indicator light of the display part 20. In this case, the first indicator light turns on, so that the operator of the wheel loader W knows that the transport of the raw ore by the belt conveyor 6 has been interrupted, i.e., the hopper 5 is empty, and can promptly input raw ore into the Static Grizzly 1.

[0035] In the above-mentioned ON / OFF control of the first indicator light, the first indicator light is not turned on while the raw ore is being transported by the belt conveyor 6, so that the problem of excessive raw ore being put into the hopper can be prevented. In other words, if the first indicator light is turned off when the transport of the raw ore by the belt conveyor 6 is interrupted, there is a risk that the operator of the wheel loader W will continue to put raw ore into the Static Grizzly 1 when the first indicator light goes out due to a malfunction. It is preferable to use a rotating light as this first indicator light, and it is desirable that the color of the rotating light be different from the colors of the permission indicator light and the prohibition indicator light of the second indicator light described later.

[0036] In addition to the first indicator light, the display unit 20 has second indicator lights consisting of a permission indicator light and a prohibition indicator light that indicate the operation status of the belt conveyor 6. The former permission indicator light is an indicator light that lights up, for example, blue when the belt conveyor 6 is operating. On the other hand, the latter prohibition indicator light is an indicator light that lights up, for example, red when the belt conveyor 6 stops operating for some reason. The operator of the wheel loader W determines whether or not to input raw ore into the Static Grizzly 1 by referring to the lighting status of the permission indicator light and prohibition indicator light of the second indicator light in addition to the lighting or extinguishment of the first indicator light (rotating light), as shown in Table 1 below.

[0037] [Table 1]

[0038] As shown in Table 1 above, the operator of the wheel loader W loads raw ore into the Static Grizzly 1 only in mode 1 when the permission indicator light is on, the prohibition indicator light is off, and the rotating light is on. In mode 2, the permission indicator light and prohibition indicator light are the same as in mode 1, but since the rotating light is off, the operator only prepares for loading so that the hopper 5 does not overflow. In modes 3 and 4, the operation of the belt conveyor 6 has stopped for some reason, so loading work is not performed regardless of whether the rotating light is on or off. Next, the present invention will be described in more detail with reference to examples and comparative examples. EXAMPLES

[0039] (Comparative Example) In a hydrometallurgical plant where raw ore is treated by the HPAL method, the raw ore, nickel oxide ore stored outdoors in a stockpile state, was charged into the static grizzly of the pretreatment facility using a wheel loader in order to be crushed and classified in the pretreatment facility. At that time, as shown in Figures 6(a) and (b), the inside state of the hopper 5 and the conveying state of the raw ore on the belt conveyor 6 were visually confirmed by worker O, and the operator of the wheel loader W was instructed to allow or prohibit charging based on the results of the confirmation.

[0040] That is, as shown in Fig. 6(a), when the transport of the raw ore by the belt conveyor 6 is interrupted, the "adding permitted" signboard is raised, and as shown in Fig. 6(b), when the raw ore is continuously transported by the belt conveyor 6, the "adding prohibited" signboard is raised. This means that the operator of the wheel loader W is instructed to add raw ore when all the raw ore that has been added is discharged from the hopper 5 and the conveyor belt 6 stops transporting the raw ore.

[0041] The operator of the wheel loader W was made to decide whether to load or stop the raw ore after checking the above-mentioned signal of "loading permission" or "loading prohibition" from the worker O, as well as the indicator light that indicates whether loading permission or prohibition of the raw ore is installed next to the hopper 5. As shown in Fig. 6(a), the indicator light for loading permission (blue) is lit while the belt conveyor 6 is in operation, and as shown in Fig. 6(b), the indicator light for prohibition of loading (red) is lit when the belt conveyor 6 is stopped.

[0042] As a result, due to human error such as a mistake in visually checking the condition of the raw ore inside the hopper by worker O as shown in Fig. 7(a) or a lack of communication between worker O and the operator of the wheel loader W as shown in Fig. 7(b), even though raw ore remained in the hopper 5 and on the belt conveyor 6, the wheel loader W continued to load more raw ore, causing excessive accumulation of raw ore in the hopper 5, which resulted in the belt conveyor 6 becoming overloaded and the safety device activating and stopping it. In order to restart the belt conveyor 6, transportation by the wheel loader W had to be stopped and the raw ore in the hopper 5 had to be removed manually, which affected the processing in the downstream leaching process and subsequent processes, and reduced the production volume of the hydrometallurgical plant.

[0043] (Example) A conveyance status display system consisting of a detector 10 and a display unit 20 as shown in FIG. 2 was introduced into the pretreatment facility of the hydrometallurgical plant of the comparative example, and the operator of the wheel loader W was made to input raw ore into the Static Grizzly 1 based on the modes 1 to 4 shown in Table 1 displayed by the display unit 20. The detector 10 used had a structure in which three band-shaped rockers 13 made of carbon steel with a width of 50 mm were suspended from a rod-shaped part 11 at a distance of 500 mm from each other as shown in FIG. 4. The height of the rod-shaped part 11 was adjusted so that the tip of each rocker 13 was 50 mm away from the conveyor surface of the belt conveyor 6, and a signal was output to the display unit 20 when the inclination angle θ of the rocker 13 became less than 20°. In addition, a Patlite (registered trademark) was adopted as the first indicator light of the display unit 20, and the indicator light indicating input permission or input prohibition of the comparative example was adopted as the second indicator light.

[0044] As a result, the average interval between feeding raw ore became 85 seconds, which was shortened by about 30 seconds compared to the average feeding interval of 116 seconds in the case of feeding based on instructions from worker O in the above comparative example, as shown in Table 2 below. In addition, the problem of clogging of hopper 5 due to excessive feeding of raw ore into hopper 5 caused by human error no longer occurred. Note that in feeding No. 6 in the comparative example, the feeding interval became 50 seconds due to an instruction error by worker O, causing the hopper 5 to become clogged.

[0045] [Table 2] [Explanation of symbols]

[0046] 1. Static Grizzly 2 Shots 3 Vibrating sieve machine 4. Oversized Shot 5. Hopper 5a Scraping board 6. Conveyor Belt 6a Frame 7 Legs 8 Base 9 Side Plate 10 Detectors 11 Rod-shaped part 12 Support part 13. Rocking Body 14 Sensor section 15 Stopper 20 Display section W Wheel Loader O Worker

Claims

1. the conveyor belt conveying the raw ore supplied from the lower end of the hopper detects an interruption in the conveyance of the raw ore and outputs a signal; and an indicator having a first indicator light turned on by the signal output from the detector and a second indicator light for indicating the operating status of the conveyor belt, the detector is composed of a rod-shaped portion extending across the belt conveyor at a position above the belt conveyor and immediately downstream of the lower end of the hopper, a support portion rotatably supporting the rod-shaped portion, a plurality of swinging bodies hanging down from the rod-shaped portion and capable of swinging freely, and a sensor portion which detects that the tilt angle of the swinging body when it comes into contact with the raw material ore being transported by the belt conveyor becomes less than a predetermined angle and outputs a signal; A conveying status display system, characterized in that the detector further includes a stopper formed of an elastic material to prevent the oscillating body from oscillating in a direction opposite to the conveying direction of the belt conveyor.

2. 2. The conveying status display system according to claim 1, wherein the distance between the tip of the oscillator and the conveyor surface of the belt conveyor is 30 mm or more and 70 mm or less, and the predetermined angle is within a range of 15 to 30 degrees.

3. 3. A raw ore pretreatment facility comprising an inclined coarse screen for removing coarse particles contained in raw ore, a vibrating sieve for sieving the raw ore that has passed through the coarse screen, a hopper for temporarily storing the raw ore that has passed through the vibrating sieve, and a belt conveyor for transporting the raw ore discharged from the lower end of the hopper, wherein the conveyor has a transport status display system as described in claim 1 or 2 installed therein.

4. The raw ore pretreatment equipment described in claim 3, characterized in that a raw ore scraping plate is provided at the lower end of the hopper, and the distance between the lower end of the scraping plate and the conveyor surface of the belt conveyor is 500 mm or more and 540 mm or less.

5. 5. The raw ore pretreatment facility according to claim 3 or 4, wherein the raw ore is nickel oxide ore having a moisture content of 20% by mass or more and 50% by mass or less.

Images