JP6836166B2 - Wear-resistant protective cover and wear-resistant sieve using it - Google Patents

Description

The present invention relates to a wear-resistant protective cover and a wear-resistant sieve using the same. Specifically, a wear-resistant protective cover that is installed at the outlet of an industrial furnace and is used by covering a metal rod (so-called grizzly bar) that constitutes an wear-resistant sieve that is expected to be used in a high-temperature environment of 700 ° C or higher. The present invention relates to an abrasion resistant sieve configured by a grizzly bar covered with such an abrasion resistant protective cover.

Large-sized wear-resistant material, also commonly referred to as grizzly bear, to separate large lumps and other bulky materials mixed in high-temperature waste discharged from industrial furnaces that perform various heat treatments. Sieve (in this specification, this is referred to as "wear resistant sieve") is used.

In general, an wear-resistant sieve has a structure in which grizzly bars made of metal rod-shaped members are arranged in parallel with each other (see FIG. 1). The wear-resistant sieve as shown in the figure is installed on the discharge end side of a rotary kiln that discharges zinc oxide burnt ore that has reached a high temperature of about 900 to 1200 ° C. in the manufacturing process of zinc oxide ore by the Waelz process, for example. It is used as a device for separating the discharged high-temperature burnt ore into granular pellets that can be transported as they are in the next process and huge lumps that cannot be transported. The huge lumps that remain on the grizzly bar and are separated and recovered are discharged to a dedicated outlet.

The zinc oxide burnt ore still maintains a high temperature state of about 700 to 900 ° C. even at the time of discharge. As represented by this example, the grizzly bar constituting the wear-resistant sieve is usually constantly exposed to a violent collision with a vigorous falling hot burnt ore or agglomerates. Therefore, a protective member (referred to as "wear-resistant protective cover" in the present specification) that is resistant to high-temperature brittleness is usually installed on the top surface side thereof.

Here, the conventional "wear-resistant protective cover" for a wear-resistant sieve is a wear-resistant material in a plurality of box-shaped and triangular prism-shaped cells formed by the iron plate 51, as in the wear-resistant protective cover 5 shown in FIG. Those having a triangular roof-like outer shape formed by a complicated structure in which 52 is embedded by thermal spraying have been widely used. Therefore, it takes time and effort to manufacture the wear-resistant protective cover, and since a large amount of expensive wear-resistant material is used, the manufacturing cost is very high.

On the other hand, a grizzly bar having a structure in which a ceramic member is fixed to the upper portion thereof has also been proposed (see Patent Document 1). However, since this wear-resistant protective cover is made of ceramic, it cannot have as much impact resistance as a metal-based wear-resistant material. Therefore, for example, the impact resistance is insufficient for use in places where constant collision with high-temperature powders, granules or lumps is expected as described above, and the range of usage conditions thereof. Had significant restrictions.

Japanese Unexamined Patent Publication No. 2002-219416

An object of the present invention is that, for example, it can be sufficiently used in a situation where constant collision with a high-temperature powder, granule or lump is expected in a high-temperature environment of 700 ° C. or higher. It is an object of the present invention to provide a wear-resistant protective cover for a grizzly bear of a wear-resistant sieve, which has excellent wear resistance in an environment, yet has a simple structure and can be manufactured at low cost.

As a result of diligent studies, the present inventor has found that the above problems can be solved by an inexpensive and easily available wear-resistant protective cover having a simple structure in which general-purpose wear-resistant plate materials are laminated. I came up with the idea and completed the present invention. Specifically, the present invention provides the following.

(1) An wear-resistant protective cover for a grizzly bar of an wear-resistant sieve, which includes a core portion and an outer shell portion that covers both side surfaces and the top surface side of the core portion. Both the core portion and the outer shell portion are made of a wear-resistant plate material having an wear-resistant layer formed on one surface of a metal flat plate, and the core portion is formed of a plurality of the wear-resistant plate materials. When installed on the grizzly bar, the grizzly bars are laminated in parallel along a direction perpendicular to the installation surface of the grizzly bar, and the outer shell portion is formed by the wear-resistant plate material and the wear-resistant layer on the surface. A wear-resistant protective cover that is joined to both side surfaces and the top surface side of the core portion in a manner exposed to the surface.

According to the invention of (1), the wear-resistant protective cover has a simple structure in which an inexpensive and easily available wear-resistant material is simply laminated. As a result, it has sufficient wear resistance in a situation where constant collision with high-temperature powders, granules or lumps is expected in a high-temperature environment of 700 ° C. or higher, and yet it is low. A wear-resistant protective cover for grizzly bears that can be manufactured at low cost can be obtained.

(2) The width of the plurality of laminated wear-resistant plate materials gradually decreases toward the top surface side of the wear-resistant protective cover, so that the wear-resistant plate material is on the top surface side of the core portion. A mountain-shaped inclined surface is formed along both side ends of the sex plate material, and the wear-resistant plate material is joined to the inclined surface to form a gable roof-shaped outer shell portion on the top surface side. The wear-resistant protective cover according to (1).

According to the invention of (2), a gable roof-shaped outer shell portion is provided on the top surface side of the wear-resistant protective cover of (1) only by changing the cut width of the wear-resistant plate material constituting the core portion. It was assumed that it was formed. According to this, while maintaining the merit of the invention of (1) that it can be manufactured at low cost, the shape of the top surface side of the wear-resistant protective cover that covers the top surface side of the grizzly bar is the gable roof shape. It is possible to avoid the accumulation, accumulation and sticking of powder and the like that should be sieved below the wear-resistant sieve on the grizzly bar, and contribute to further improvement of the durability of the wear-resistant protective cover itself. it can.

(3) The wear-resistant protective cover according to (1) or (2), wherein the wear-resistant material constituting the wear-resistant layer of the wear-resistant plate is a high-chromium cast iron-based wear-resistant material.

According to the invention of (3), the wear-resistant plate material used in the wear-resistant protective cover of (1) or (2) is a general-purpose wear-resistant member, which is easily available, and has heat resistance and wear resistance. A high-chromium cast iron-based wear-resistant material with excellent properties was used. As a result, the above-mentioned effects of the invention of (1) or (2) can be enjoyed more easily with higher accuracy and also in terms of economy.

(4) An wear-resistant sieve in which the wear-resistant protective cover according to any one of (1) to (3) is installed so as to cover the top surface side of the grizzly bar.

According to the invention of (4), in the wear-resistant sieve that is expected to be used in the high temperature environment as described above, the wear-resistant sieve is included by reducing the frequency of repair and replacement of the grizzly bar or its protective cover. The productivity of the manufacturing plant can be improved.

(5) Sorting of fired products, which comprises an industrial furnace for discharging granular or powdery fired products fired at 700 ° C. or higher, and a wear-resistant sieve according to (4) installed on the discharge end side of the industrial furnace. Facility.

According to the invention of (5), for example, at the discharge end of a rotary kiln that discharges a fired product having a high temperature of 700 ° C. or higher, the operating efficiency of equipment for sorting coarse discharge in the fired product is improved by a wear-resistant sieve. Can be made to.

(6) A wear-resistant sieve according to (4) is installed on the discharge end side of a rotary kiln for a reduction roasting process and / or a rotary kiln for a drying and heating process in a zinc oxide ore production plant by the Waelz process. Zinc oxide ore manufacturing plant.

According to the invention of (6), the wear-resistant sieve of (4) can be used in a zinc oxide ore production plant by the Waelz process. According to this, as a technology for efficiently and economically recovering zinc in iron scrap, it is possible to contribute to improving the productivity of the above-mentioned manufacturing plant, which greatly contributes to resource recycling in Japan, which does not have mineral resources. ..

According to the present invention, it can be sufficiently used in a situation where constant collision with a high-temperature powder, granule or lump is expected in a high-temperature environment, and wear resistance in such an environment. It is possible to provide a wear-resistant protective cover for a grizzly bear of an wear-resistant sieve, which is excellent in structure and can be manufactured at low cost with a simple structure.

It is a top view of the wear-resistant sieve provided with the grizzly bar in which the wear-resistant protective cover of the present invention is installed on the top surface side. It is an elevation view which shows typically the whole structure of the wear-resistant sieve shown in FIG. FIG. 5 is a perspective view of an embodiment in which the wear-resistant protective cover of the present invention is installed on the top surface side of the grizzly bar. It is a front view and the top view which show the structure of the wear-resistant protective cover of this invention. FIG. 5 is a perspective view of an embodiment in which a conventional wear-resistant protective cover is installed on the top surface side of a grizzly bar.

Hereinafter, a preferred embodiment of the wear-resistant protective cover of the present invention and the wear-resistant sieve using the cover will be described. The present invention is a large industrial sieve having a function of being installed on the discharge end side of various industrial furnaces for discharging powdery, granular or lumpy high-temperature discharges and selecting coarse discharges from these discharges. It is a technology that can be widely applied in general. As a specific example, as described above, this technique can be preferably used on the discharge end side of a rotary kiln that discharges zinc oxide burnt in the process of producing zinc oxide ore by the Waelz process. In the following, when the wear-resistant protective cover of the present invention and the wear-resistant sieve using the same are applied to the production process of zinc oxide ore, more specifically, the wear-resistant protective cover on the discharge end side of the rotary kiln constituting the process. An embodiment when used in a manufacturing plant equipped with a wear sieve will be described in detail as an example of a preferred embodiment of the present invention. However, the present invention is not limited to the embodiments described below, and changes can be made without changing the gist of the present invention.

<Abrasion resistant sieve>
As shown in FIGS. 1 and 2, the wear-resistant sieve 10 has a sieving surface formed by arranging a plurality of grizzly bars 2 in parallel, and sifts high-temperature powder and high-temperature lumps. It is a large sorting device that can be used. Each grizzly bar 2 is made of a metal rod-shaped member, and covers the top surface side of the grizzly bar 2, that is, the side where high-temperature burnt ore constantly hits directly when the wear-resistant sieve 10 is used. A wear resistant protective cover 1 is installed.

The wear-resistant sieve 10 is installed at a position where the high-temperature discharge can be dropped onto the grizzly bar 2 on the discharge end side of an industrial furnace that discharges high-temperature discharge such as a rotary kiln constituting a zinc oxide ore manufacturing plant. Will be done. Then, as shown in FIG. 2, the wear-resistant sieve 10 is usually installed so that the sieve surface formed by the grizzly bar 2 is an obliquely oriented surface.

Further, as shown in FIG. 2, the wear-resistant sieve 10 is attached by attaching the grizzly bar 2 in a state where its end is connected to the disc plate 3 eccentrically installed with respect to the rotation axis. It is preferable that the grizzly bar 2 reciprocates up and down once as the rotation shaft makes one rotation. Further, it is more preferable that the adjacent grizzly bars 2 are attached so that the phases of the eccentricity of the adjacent grizzly bars 2 are displaced by 180 degrees, so that the adjacent grizzly bars 2 repeatedly move up and down in opposite directions. A wear-resistant sieve in which the grizzly bar 2 is installed in such a swingable manner is also referred to as a swaying rostrum. The wear-resistant sieve 10 of the present invention can be preferably applied to such a swaying rostrum. Such a swaying rostrum can prevent the accumulation, accumulation, and sticking of discharges such as powder that should be sieved below the wear-resistant sieve on the sieve surface with higher accuracy, and the huge amount remaining on the sieve surface. Productivity of the manufacturing plant in which this is placed as an abrasion-resistant sieve with high sorting ability, which has few problems such as clogging due to large lumps and can quickly discharge the huge lumps remaining on the sieve surface. It can contribute significantly to the improvement.

For example, in the process of producing zinc oxide ore by the Waelz process, when high-temperature discharges in which agglomerates and powders are mixed from a rotary kiln for drying and heating are sieved by the wear-resistant sieve 10, a plurality of grizzly bars are used. Of the high-temperature powders, granules or lumps dropped on the sieve surface of the abrasion-resistant sieve 10 composed of 2, only lumps having a certain size or larger remain on the grizzly bar 2. , It rolls on a sieve surface arranged so as to be an inclined surface and is discharged to a dedicated discharge port. Then, the powdery substance, the granular substance or the lumpy substance having a particle size of a certain value or less falls downward from the sieve surface and is carried out to the next step by the conveyor 4.

<Abrasion resistant protective cover>
As shown in FIG. 3, the wear-resistant protective cover 1 is installed so as to cover the top surface side of the grizzly bar 2 constituting the wear-resistant sieve 10.

As shown in FIGS. 3 and 4, the wear-resistant protective cover 1 is configured to include at least core portions 11 and 12 and outer shell portions 13 and 14 covering the core portions 11 and 12. The wear-resistant protective cover 1 has a simple structure in which the core portions 11 and 12 and the outer shell portions 13 and 14 are all made of a wear-resistant plate material that is easily available as a general-purpose member. It is characterized by that.

The wear-resistant plate materials 111 and 121 constituting the wear-resistant protective cover 1 are particularly limited to metal plate materials having a wear-resistant layer formed on one surface and having desired heat resistance and wear resistance. Various metal plate materials can be appropriately used without limitation. However, a metal plate whose wear-resistant layer is formed by a high-chromium cast iron-based wear-resistant material that has a good balance of heat resistance, wear resistance, and availability including price due to being a general-purpose product is resistant. It can be particularly preferably used as the wear-resistant plate materials 111 and 121. As the metal plate subjected to the wear-resistant treatment with a high-chromium cast iron-based wear-resistant material, for example, a TOP plate (trade name “TOP Gr-C”) manufactured by Tokuden Co., Ltd. can be used. The component of "TOP Gr-C" is a high Cr cast iron-based + composite carbide, and the hardness is 80HS or more and 90HS or less in shore hardness.

As shown in FIGS. 3 and 4, the core portions 11 and 12 of the wear-resistant protective cover 1 have a plurality of wear-resistant plate members 111 and 121 with respect to the installation surface of the grizzly bar 2 when they are installed on the grizzly bar 2. It consists of a structure in which the bears are stacked in parallel along the vertical direction. It is preferable that the wear-resistant plate members 111 and 121 to be laminated are joined by thermal spraying of a chromium-based wear-resistant material.

Further, as shown in FIGS. 3 and 4, the wear-resistant protective cover 1 preferably has a gable roof-shaped outer shell portion formed on the top surface side thereof. Of the core portions 11 and 12, in a part of the core portion 11 and 12 closer to the top surface side (top surface side core portion 12), the widths of the wear-resistant plate members 121a to 121 constituting this portion are wear-resistant as shown in FIG. By making the protective cover 1 gradually decrease toward the top surface side, a mountain-shaped inclined surface is formed along both side ends of the wear-resistant plate members 121a to 121, thereby forming a single type. The shape of the top surface of the core can be made into such a gable roof shape only by a simple process of changing the cut width of the plate material. Regarding the shape of the gable roof on the top surface side, the apex angle of the gable roof, that is, the angle formed by the two inclined surfaces is, for example, 90 ° can be mentioned as an example of the preferable angle. ..

Further, as shown in FIGS. 3 and 4, the outer shells 13 and 14 of the wear-resistant protective cover 1 have the core portions 11 and 12 in such a manner that the wear-resistant plate material is exposed on the surface. It consists of a structure that is joined to both sides and the top surface. The wear-resistant plate materials forming the outer shells 13 and 14 are preferably joined to the cores 11 and 12 by thermal spraying of a chromium-based wear-resistant material.

As shown in FIGS. 3 and 4, when the wear-resistant protective cover 1 has a gable roof-shaped outer shell formed on the top surface side thereof, the core portions 11 and 12 are closer to the bottom surface side. The outer shell portion 13 (side surface side outer shell portion 13) is on the side surface of a part (bottom side core portion 11), and the outer shell portion 14 is on both inclined surfaces of the gable roof-shaped top surface side core portion 12. (Top surface side outer shell portion 14) are joined to each other to form the outer shell portion of the wear resistant protective cover 1.

It is preferable that the wear-resistant protective cover 1 is further provided with a connecting portion 15 that can be easily installed on the grizzly bar 2 and can improve the stability of the connecting portion after installation. .. The connecting portion 15 is preferably a member having a U-shaped cross section as shown in FIG. 3, and may be a member processed from a steel material or the like, but the core portions 11 and 12 and the outer shell portions 13 and 14 It is more preferable that the same wear-resistant plate material as the one constituting the above is processed and formed into the above shape. As for the joining between the connecting portion 15, the core portions 11, 12, and the outer shell portions 13, 14, it is preferable to join by spraying a chromium-based wear-resistant material as described above. It is preferable that the connection portion 15 and the grizzly bar 2 are fixed by tightening with removable bolts or the like so that the replacement work can be easily performed at the time of wear.

<Zinc oxide ore manufacturing plant>
The production plant for zinc oxide ore by the Waelz process is a reduction roasting process in which zinc-containing ore such as steel dust is reduced and roasted to obtain crude zinc oxide dust, and fluorine and cadmium from the crude zinc oxide dust obtained in the reduction roasting process. An industrial plant that carries out a process of sequentially performing a wet step of obtaining a crude zinc oxide cake by separating and removing such substances, and a drying and heating step of drying and heating the crude zinc oxide cake obtained in the wet step to obtain zinc oxide ore (roasted ore). Is. The present invention is the rotary kiln for reduction roasting (RRK) used in the above-mentioned reduction roasting step, the rotary kiln for drying and heating (DRK) used in the drying and heating step, or the same plant in such a zinc oxide ore production plant. It can be preferably used as a fired product sorting device installed on the discharge end side of both of these rotary kilns to screen out high temperature discharges up to 700 ° C. or higher.

[Reduction roasting process]
In the reduction roasting step, a process of reducing and roasting a raw material or the like in which steel dust is pelletized together with a reducing material in advance by a rotary kiln for reduction roasting (RRK) is performed. In this reduction roasting process, the maximum temperature of the object to be processed is controlled to be about 1100 to 1200 ° C. The RRK is provided with an oil burner on the discharge end side for discharging the residue (clinker), and is heated by a direct fire from the discharge end side. The exhaust gas temperature on the charging end side is controlled at an appropriate temperature within the range of 400 ° C. to 700 ° C. And in RRK, by adding limestone as a calcium source, the melting point of the residue in the furnace is raised and adjusted so that the beco does not adhere to the kiln, but coke etc. whose combustion state is easy to maintain The use of charcoal material, and the reduced metallic iron is rapidly oxidized in the kiln when the carbon monoxide gas concentration decreases, and heat is generated during the oxidation reaction, resulting in the residue especially near the discharge end. The temperature tends to be high, and due to this, beco is likely to be generated on the discharge end side in the furnace. Therefore, in many cases, a device called a coaching cutter for preventing excessive generation of the beco is provided, which mechanically scrapes off the beco during the kiln operation. In this case, the RRK discharge is a lump. Some peeled beco may be mixed. In particular, in such RRK, it is essential to provide an wear-resistant sieve on the discharge end side of the object to be treated. Then, in the wear-resistant sieve installed in such an embodiment, the wear-resistant protective cover of the present invention can be used extremely preferably.

[Wet process]
In the wet step following the reduction roasting step, water-soluble impurities such as chlorine, fluorine, and cadmium contained in the crude zinc oxide dust obtained in the reduction roasting step are separated and extracted into the treatment liquid, and further solid-liquid separation treatment is performed. A wet treatment is performed in which impurities are removed from the crude zinc oxide dust by a water washing method to obtain a crude zinc oxide cake.

[Drying and heating process]
In the drying and heating step, the crude zinc oxide cake obtained in the wet step is put into a rotary kiln (DRK) for drying and heating and calcined to produce a high-grade zinc oxide ore while further reducing the halogen concentration. Perform processing. The crude zinc oxide cake is charged into the DRK in the form of a hydrous cake by a quantitative charging device such as a screw feeder. The crude zinc oxide cake charged into the DRK is granulated into pellets on the charging end side inside the rotary kiln, then dried, heated, and fired on the discharging end side. The DRK is provided with an oil burner on the discharge end side for discharging zinc oxide ore, and is heated by a direct flame from the discharge end side. The temperature of the zinc oxide ore burnt discharged from the rotary kiln is maintained and managed so as to be in the range of 900 ° C. or higher and 1200 ° C. or lower. Similar to RRK, in DRK, the zinc oxide ore on the discharge end side near the flame of the burner tends to become high in temperature, and beco is likely to be generated in the kiln on the discharge end side. Therefore, in the DRK, the deposits adhering to the inner wall may be peeled off and discharged as a large mass from the discharge end of the kiln. If a mass of a certain size or larger is discharged and carried out to the next process as it is, it may cause various failures and production troubles, so it has a sorting function to sort and separate it. It is necessary to install a wear-resistant sieve. Then, in the wear-resistant sieve installed in such an embodiment, the wear-resistant protective cover of the present invention can be used extremely preferably.

As a wear-resistant plate material that has been subjected to wear-resistant treatment with a high-chromium cast iron-based wear-resistant material, the TOP plate manufactured by Tokuden Co., Ltd. (trade name "TOP Gr-C", base material thickness 6 mm, wear-resistant layer) A wear-resistant protective cover having a gable roof shape as shown in FIG. 3 was manufactured using a thickness of 6 mm and a total thickness of 12 mm), and its effect was verified by a test operation.

As for the core portion, the above wear-resistant plate material was cut into a length of 500 mm and a width of 100 mm, six plates were laminated, and the plate materials were welded and joined to each other to form a rectangular parallelepiped bottom side core portion. Further, on the top surface side of the bottom surface side core portion, the above-mentioned wear-resistant plate material cut into a length of 500 mm and a width of 76 mm is superposed, and the plate material is cut into a length of 500 mm and a width of 52 mm. The same plate material was cut into a length of 500 mm and a width of 28 mm, and the plates were sequentially laminated and welded to each other to form a gable roof-shaped top side core portion.

Regarding the outer shell portion, the above-mentioned wear-resistant plate material cut into a length of 500 mm and a width of 76 mm is welded and joined to both side surfaces of the bottom surface side core portion 11 formed as described above, and the side surface outside A shell was formed. Further, the above wear-resistant plate material cut into a length of 500 mm and a width of 71 mm is welded and joined to both slopes on the top surface side of the bottom surface side core portion 11 formed as described above, and the top surface side is formed. The outer shell was formed.

Each of the above wear-resistant plate materials was joined with a tensile strength class 60 wire, and the joined portion was hardened and built-up with a Cr-Nb-V welding rod. Further, the same hardening overlay treatment was performed on the gaps between the plate materials.

The wear-resistant protective cover manufactured as described above is attached to the grizzly bar of the wear-resistant sieve installed on the discharge end side of the rotary kiln (DRK) for drying and heating in a manufacturing plant that manufactures zinc oxide by the Waelz process, and tested. It has been in operation for half a year. Before the start of this test operation, the wear-resistant protective cover having the conventional structure shown in FIG. 5 was attached. As shown in FIG. 5, this conventional structure wear-resistant protective cover has a structure in which a wear-resistant material is embedded in a plurality of box-shaped and triangular prism-shaped cells formed by an iron plate 51 by thermal spraying, and is wear-resistant. As the wear material, a high chrome cast iron-based wear-resistant material similar to the wear-resistant material of the above-described embodiment was used.

The manufacturing time of the wear-resistant protective cover of the example was reduced to about half as compared with the conventional structure. In addition, the manufacturing cost could be reduced to 60% as compared with the conventional structure. On the other hand, the degree of wear of the wear-resistant protective cover after the test operation was continued for half a year was comparable to that of the conventional structure.

Based on the above, the wear-resistant protective cover of the present invention has a simple structure and can be manufactured at low cost, but has excellent wear resistance in a high temperature environment of 700 ° C. or higher. Repair of the grizzly bar or its protective cover It was confirmed that the frequency of replacement can be reduced to improve the productivity of a production plant including a wear-resistant sieve, which is represented by a production plant of zinc oxide ore by the Waelz process.

1 Abrasion resistant protective cover 11, 12 Core part 111, 121 Abrasion resistant plate material 13, 14 Outer shell part 15 Connection part 3 Disc plate 4 Conveyor 5 Abrasion resistant protective cover (conventional type)
51 Iron plate 52 Abrasion resistant material 10 Abrasion resistant sieve

Claims (6)

A wear-resistant protective cover for grizzly bars on wear-resistant sieves.
It includes a core portion and an outer shell portion that covers both side surfaces and the top surface side of the core portion.
Both the core portion and the outer shell portion are made of a wear-resistant plate material in which a wear-resistant layer is formed on one surface of a metal flat plate.
The core portion is formed by laminating a plurality of the wear-resistant plate materials in a direction perpendicular to the installation surface of the grizzly bar at the time of installation on the grizzly bar.
The outer shell portion is a wear-resistant protective cover in which the wear-resistant plate material is joined to both side surfaces and the top surface side of the core portion in such a manner that the wear-resistant layer is exposed on the surface. By gradually reducing the width of the plurality of laminated wear-resistant plate materials toward the top surface side of the wear-resistant protective cover, the wear-resistant plate material is placed on the top surface side of the core portion. A mountain-shaped sloping surface is formed along both ends,
By joining the wear-resistant plate material to the inclined surface,
The wear-resistant protective cover according to claim 1, wherein a gable roof-shaped outer shell portion is formed on the top surface side. The wear-resistant protective cover according to claim 1 or 2, wherein the wear-resistant material constituting the wear-resistant layer of the wear-resistant plate material is a high-chromium cast iron-based wear-resistant material. A wear-resistant sieve in which the wear-resistant protective cover according to any one of claims 1 to 3 is installed so as to cover the top surface side of the grizzly bar. An industrial furnace for discharging granular or powdery fired products fired at 700 ° C. or higher, and a fired product sorting facility in which the wear-resistant sieve according to claim 4 is installed on the discharge end side of the industrial furnace. It is a production plant of zinc oxide ore by the Waelz method.
A zinc oxide ore manufacturing plant in which the wear-resistant sieve according to claim 4 is installed on the discharge end side of the rotary kiln for the reduction roasting process and / or the rotary kiln for the drying and heating process.

Images