Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
  • B02C17/18—Details
  • B02C17/183—Feeding or discharging devices
  • B02C17/1835—Discharging devices combined with sorting or separating of material
  • B02C17/1855—Discharging devices combined with sorting or separating of material with separator defining termination of crushing zone, e.g. screen denying egress of oversize material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C23/00—Auxiliary methods or auxiliary devices or accessories specially adapted for crushing or disintegrating not provided for in preceding groups or not specially adapted to apparatus covered by a single preceding group

Definitions

• the invention relates to grinding mills, and more particularly to a grate panel, a grate panel support element, an arrangement at a grinding mill discharge end and a method for disassembling a discharge end of a grinding mill.
• Open-ended mills can provide a solution to this problem removing the need for pulp lifters such that slurry can flow unhindered though the grate and out of the mill.
• the maintenance of open-ended grinding mills has caused some difficulties, since it has been necessary to mount and unmount at least some of the structural parts from the inside of the grinding mill, whereby at least some work phases have required workers to get inside the grinding mill volume to do some of the maintenance tasks. This typically lengthens the maintenance breaks and can even risk the occupational safety of the workers.
• An object of the present invention to provide a new grate panel, a new grate support element, a new arrangement at a grinding mill discharge end, and a method for disassembling a discharge end of a grinding mill, which are character ized by what is stated in the independent claims. Some preferred embodiments are disclosed in the dependent claims.
• the invention is based on the idea of configuring grate panels and grate support elements in such a manner that mounting and unmounting of the main parts of the discharge end of an open-ended grinding mill can be done from the outside of the grinding mill.
• An advantage of the method and arrangement of the new grate panel, the new grate support element, the new arrangement at a grinding mill discharge end and the new method for disassembling a discharge end of a grinding mill is that the maintenance of the grate is quicker and easier.
• the method according to the current solution also enables more efficient use of machinery and even robots and automation. The current solution can, therefore, reduce the number and/or dura tion of maintenance breaks needed and improve occupational safety.
• Figure 1 illustrates schematically a grinding mill seen from a side
• Figure 2 illustrates schematically an open-ended grinding mill seen from the second end
• Figure 3 shows a part of an open-ended grinding mill in perspective
• Figure 4 shows a detail from a discharge end of an open-ended grinding mill in perspective
• Figure 5 shows a detail from a discharge end of an open-ended grinding mill shown from a side of the grinding mill;
• Figure 6 shows a grate support element according to an example of an embodiment
• Figure 7 shows a grate panel according to an example of an embodiment and shown in perspective from the side configured to be directed to the outside of the grinding mill;
• Figure 8 shows a detail of a grinding mill at the discharge end according to an embodiment;
• Figures 9 and 10 illustrate different embodiments of grate panels
• Figures 11 to 19 illustrate schematically details of cross sections of grate panels according to different embodiments
• Figure 20 illustrates an example embodiment of an arrangement at a grinding mill discharge end
• Figure 21 illustrates an embodiment of a method for disassembling a discharge end of a grinding mill.
• the drawings are for illustrative purposes only and are not shown is scale. For the sake of clarity, not all the similar features have been numbered in the figures.
• Figure 1 illustrates schematically a grinding mill 2.
• Figure 2 illustrates schematically a grinding mill 2 seen from a second end 10, in other words the dis charge end 10 of the grinding mill.
• Figures 1 and 2 only show some features of the grinding mill 1 that help understanding the current solution. It is clear for a person skilled in the art that a grinding mill may and usually does comprise other features as well.
• a grinding mill 2 such as the grinding mill of Figure 1, comprises a drum comprising a cylindrical shell 11.
• the longitudinal axis 9 of the drum is arranged in a substantially horizontal position in a use position of the grinding mill 2.
• the longitudinal axis 9 of the drum refers to the axis extending along the centre line of the shell 11 from one end of the cylinder shaped shell to another.
• Horizontal position refers to the longitudinal axis 9 ex tending in a substantially horizontal direction.
• the longitudinal axis 9 extends in a direction that is closer to a horizontal direction than a vertical direc tion.
• the use position refers to a position the grinding mill 2 is arranged in when used for grinding, for instance for ore grinding, in a production environment.
• the drum comprises a first end 14 at the feed end of the shell and a sec ond end at the discharge end 10 of the shell.
• the feed end refers to the end at which the material to be ground is fed into the drum.
• the discharge end refers to the end at which the ground material is discharged from the drum.
• the discharged material comprising ground material and possibly liquids is also called slurry in this application.
• the grinding mill 2 may comprise various process duties including but not limited to a ball mill, a pebble mill, an autogenous mill (AG mill), or a semi- autogenous mill (SAG mill). Working principles of such grinding mills are known and are not explained in more detail in this description.
• the grinding mill 2 typically further comprises a bearing 15 supporting the drum at the discharge end 10.
• the bearing 15 may comprise any suitable type of bearing, such as a rolling element bearing, a hydrostatic bearing or a hydrody namic bearing. It should also be noted that the grinding mill 2 may also have addi- tional bearings supporting the drum and/or other parts of the grinding mill 2. Such bearings 15 for supporting the drum of the grinding mill are known as such and are not explained in more detail.
• a grinding mill 2 may be an open-ended grinding mill.
• Open-ended grinding mill refers to a grinding mill that does not have a discharge trunnion, pulp lifters to lift the ground material to the discharge trunnion or a solid discharge head plate.
• An open-ended grinding mill may comprise a discharge grate 16 instead of the discharge trunnion, pulp lifter and solid discharge head plate, whereby the ground material is discharged through the discharge grate 16. In a fully open-ended grinding mill, there is no need to lift the ground material to discharge it.
• the open-ended grinding mill 2 may comprise a partial head plate 23 at the discharge end. Such a grinding mill may also be called a semi- open-ended grinding mill.
• a semi-open-ended grinding mill may be similar to the fully open-ended grinding mill, but it may have a partial head plate 23 at the dis charge end of the shell extending partially from a perimeter of the shell 11 towards the longitudinal axis 9 of the drum, but without a discharge trunnion and no tradi tional pulp lifters.
• the partial head plate 23 at the discharge end 10 of the shell 11 may extend a distance of preferably less than 50 percent, more preferably less than 30 percent and most preferably less than 15 percent of the length the radius 24 of the shell from the edge of the shell 11 towards the longitudinal axis 9 of the drum.
• the area of the discharge end 10 of the drum extending from the inner edge of the partial head plate 23 towards the longitudinal axis 9 of the drum may define a dis charge opening.
• the discharge opening may be provided with a discharge grate 16.
• the ground material may, thus, be discharged from the discharge grate 16 straight to the atmosphere.
• Figure 3 shows a part of a grinding mill 2, more particularly a part of an open-ended grinding mill 2, in perspective
• Figure 4 shows a detail from a discharge end of an open-ended grinding mill in perspective
• Figure 5 shows a detail from a discharge end of an open-ended grinding mill shown from a side of the grinding mill.
• Figure 6 shows a grate support element according to an example of an embod iment
• Figure 7 shows a grate panel according to an example of an embodiment and shown in perspective from the side configured to be directed to the outside of the grinding mill.
• a grate support element 1 for an open-ended grinding mill 2 may comprise an outer perimeter section 3, an inner section 4, and at least one vane 5.
• the vane 5 may be configured to extend between the outer perimeter section 3 and the inner section 4, for instance in a direction radial with respect to the outer perimeter 6 of the grate support element 1 or in a curved manner.
• the grate support element 1 thus, refers to an element configured to be mounted at a discharge end 10 of a shell 11 of the open-ended grinding mill 2 and to support one or more grate panel(s) of the open-ended grinding mill 2.
• the inner section 4 refers to the section of the grate support element 1, which is provided at the end of the grate support element 1 that is directed towards the middle 12 of the cross section of the grinding mill 2 at the discharge end 10, when the grate support element 1 is mounted to the grinding mill 2.
• the outer perimeter section 3 refers to the section of the grate support element 1, which is provided at the end of the grate support element 1 that is directed away from the middle 12 of the cross section of the grinding mill 2 at the discharge end 10, when the grate support ele ment 1 is mounted to the grinding mill 2, in other words at the distal end of the grate support element 1.
• Figure 8 shows a detail of a grinding mill at the discharge end according to an embodiment.
• a grate support element 1 for supporting a grate 25 of an open-ended grinding mill 2 may comprise an outer perimeter sec- tion 3 directed towards a middle 12 of the cross section of the grinding mill 2 in the transverse direction of the grinding mill 2, an inner section 4 directed away from the middle 12 of the cross section of the grinding mill 2 in the transverse direction of the grinding mill, and at least one vane 5 extending between the outer perimeter section 3 and the inner section 4 in such a manner that the vane 5 has an inner section side end connected to the inner section 4 and an outer perimeter section side end connected to the outer perimeter section 3.
• the vane 5 extending between the outer perimeter section 3 and the inner section 4 in such a manner that the vane 5 has an inner section side end connected to the inner section 4 and an outer perimeter section side end connected to the outer perimeter section 3 refers to the vane having a first end at the outer perimeter section and another end a second end at the inner section of the grate support element.
• the grate support element 1 may further comprise a mounting flange 30 at the outer perimeter of the grate support element 1.
• the mounting flange 30 is configured to enable mounting of the grate support element 1 to a shell 11 of the grinding mill 2 at an area of the shell not intruding to the grinding mill volume 28.
• the mounting flange 30 may extend outwards from the middle 12 of the cross section of the grinding mill 2.
• the mount ing flange 30 may extend from the outer perimeter end of the vane 5 in a direction directed outwards from the middle 12 of the cross section of the grinding mill 2.
• the mounting flange 30 may form a flange with a shape of a ring or a section of a ring at the outer perimeter section 3 part of the grate support element 1.
• the mounting flange 30 may be configured to extend beyond the inner perimeter of the shell 11 at the discharge end 10 and not to extend to the area of the discharge end opening of the shell 11, when the grate support element 1 is mounted to the grinding mill 2, for example to the shell 11.
• the mounting flange 30 may be configured to be mounted to the discharge end face of the grind ing mill 2, and the shell 11, and not to protrude into the inside or inner volume 28 of the shell 11, when the grate support element 1 is mounted to the grinding mill 2 via the mounting flange 30.
• the mounting flange 30 may be provided with flange openings 26 configured for bolts for mounting the grate support ele ment 1 to the grinding mill 2.
• the flange openings 26 may be configured to extend through the mounting flange 30 in a horizontal direction, when the grate support element 1 is mounted in the grinding mill 2.
• the flange openings 26 may be configured to extend in the longitudinal direction of the grinding mill 2, when the grate support element 1 is mounted to the grinding mill 2.
• at least some of the flange openings 26 may be configured as blind holes.
• the mounting flange 30 may be config ured to extend outwards beyond a diameter of an inner volume 28 of the shell 11 of the grinding mill 2, when the grate support element 1 is mounted in the grinding mill 2.
• the mounting flange 30 may be configured not to protrude to the area inside the inner perimeter of the cylindrical shell 11 of the grinding mill 2, when the grate support element 1 is mounted to the grinding mill 2. This has many benefits including not limiting the flow of ground material and avoiding a surface of high wear and a point of stiffness discontinuity at the discharge end of the shell 11.
• the grate support element 1 may com prise a mounting surface parallel to the end of the of the shell 11 of the grinding mill 2.
• this mounting surface comprises a surface within the area of the mounting flange 30. More preferably, this mounting surface comprises a surface within the area of the mounting flange 30 configured to be directed towards the shell 11, when the grate support element 1 is mounted to the grinding mill 2, such as to the discharge end of the shell.
• the vane 5 extends between the outer pe rimeter section 3 and the inner section 4 in a direction radial with respect to the cross section of the grinding mill 2 in the transverse direction.
• the vanes 5 may thus be configured to extend radially from the outer perim eter of the discharge end of the shell 11, when a plurality of grate support elements 1 or one or more grate support elements 1 comprising a plurality of vanes 5 are mounted to the grinding mill 2.
• the vane 5 extends between the outer pe rimeter section 3 and the inner section 4 in a curved manner.
• the vanes may be configured to curve for instance in a direction of a plane defined by the vanes 5 or in a direction transverse to the direction of the plane defined by the vanes 5.
• the plane defined by the vanes refers to a plane defined by the direc tion, in which the vane 5 extends from the outer perimeter section 3 towards the inner section 4.
• a curve in a direction of the plane refers to the vane being curved, or angled, with respect to the radial direction directed from the outer pe rimeter edge 8 towards the middle 12 of the cross section of the grinding mill 2, when the grate support element 1 is mounted to a grinding mill 2.
• the vane 5 may for instance be configured to extend from the outer perimeter section 3 towards the inner section in a spiralling manner.
• a curve in a direction transverse to the direction of the plane defined by the vanes 5 refers to the vane 5 being con figured to be curved towards and/or outwards from the volume of the grinding mill 2, when mounted to the grinding mill 2.
• the angle or the curvature may vary along the length of the vane 5.
• an open-ended grinding mill 2 comprises a shell 11 comprising an inner volume 28 for material to be ground and at least one grate support element 1 according to an embodiment described in this description, or a combination of such embodiments, mounted to the shell at a discharge end 10 of the grinding mill 2.
• the shell 11 comprises a shell flange 27 extending in a radial direction away from the inner volume of the shell 11, and the grate support element 1 is mounted via the mounting flange 30 to the shell flange 27.
• the mounting flange 30 and the shell flange 27 are provided with flange openings 26 for bolts for mounting the grate support element 1 to the shell 11.
• the flange openings 26 are configured to be aligned when the grate support element 1 is mounted to the shell 11.
• the flange openings 26 in the mounting flange 30 and in the shell flange 26 are preferably configured to extend through the mounting flange 30.
• the grate support element 1 is preferably mounted to the shell 11 by bolts extending in a horizontal direction through the flange openings 26 in both the mounting flange 30 and the shell flange 27, when the grate support element 1 is mounted in the grinding mill 2 and the grinding mill 2 is in a use position.
• the vane 5 is provided with at least two vane openings 19 along its length for attaching the grate support element 1 to a grate panel 20.
• the vane 5 may be angled with respect to a plane 7 defined by the outer edge 8 of the outer perimeter section 3 in such a manner that the inner section 4 is configured to be provided outwards from the plane 7 defined by the outer edge 8 of the outer perimeter section 3, when the grate support element 1 is mounted to the open-ended grinding mill 2.
• the vane 5 may be angled with respect to a plane defined by the outer perimeter of the grate support element 1.
• the inner section 4 may protrude outwards from the grinding mill volume 28, when the grate support element 1 is mounted to the open-ended grinding mill 2, more particularly at a discharge end 10 of the open- ended grinding mill 2.
• the grate support element 1 may be flat.
• the vane 5 may extend in a direction parallel, or substantially parallel, to the plane 7 defined by the outer edge 8 of the outer perimeter section 3, instead of being angled to the plane.
• the grate support element 1 in its entirety may, thus, be configured to be positioned into a vertical position when mounted to the grinding mill 2, instead of protruding outwards from the volume 28 of the grinding mill 2.
• the embodiments may otherwise be similar to one another and comprise similar features and combinations thereof.
• the angle 13 between the vane 5 and the plane 7 defined by the outer edge 8 of the outer perimeter section 3 is in the range of 5 to 30 degrees.
• the vane 5 protrudes outwards from the grinding mill volume, in other words from the inside of the shell 11, at an angle 13 in the range of 5 to 30 degrees, when the grate support element 1 is mounted to the open- ended grinding mill 2, more particularly at a discharge end 10 of the open-ended grinding mill 2.
• the angle 13 between the vane 5 and the plane 7 defined by the outer edge 8 of the outer perimeter section 3 may vary at one, two or more points along the length of the vane or continuously over the length of the vane. In other words, the angle 13 between the vane 5 and the plane
• the angle 13 between the vane 5 and the plane 7 defined by the outer edge 8 of the outer perimeter section 3 may be arranged to vary contin uously over the length of the vane 5.
• the vane 5 may thus be angled in a curved manner with respect to the plane 7 defined by the outer edge
• the vane 5 may com prise a same angle with respect to the plane 7 defined by the outer edge 8 of the outer perimeter section 3 along a first portion of the length of the vane 5 and a continuously varying angle along a second portion of the length of the vane 5.
• the grate support element 1 comprises a shape of a conical wheel or a conical disc, or a shape of a section of a conical wheel or a conical disc.
• the grate support element 1 comprising a shape of a section of a conical wheel or a conical disc refers to such a shape that a plurality of grate sup port elements 1 arranged adjacently to one other in such a manner, that their inner sections 4 are directed to a common middle point and their outer perimeter sec tions 3 are directed away from the common middle point, form a conical wheel shape or a conical disc shape.
• the grate support element 1 and a grate panel 20 are attached fixedly to one another to form a uniform structure.
• one grate support element 1 alone forms a grate support structure 22.
• a grate support structure 22 comprises at least two grate support elements 1 described in this description and the accompa nying drawings.
• an open-ended grinding mill 2 comprises a grate support structure 22 and/or at least one grate support element 1 described in this description.
• such an open-ended grinding mill 2 further comprises a grate 25 and a cylindrical shell 11, and the grate support structure 22 is mounted to the grate 25 and the cylindrical shell 11.
• the grate support structure 22 is mounted removably at least to the cylindrical shell 11.
• the middle part of the grate support structure 22 com prising the inner section of the grate support structure 22 extends outwards from the cylindrical shell. More particularly, in such an embodiment, the middle part of the grate support structure 22 comprising the inner section of the grate support structure 22 extends outwards from the cylindrical shell 11 in the longitudinal di rection of the cylindrical shell 11.
• Figures 9 and 10 illustrate different embodiments of grate panels and Figures 11 to 19 illustrate schematically details of cross sections of grate panels according to different embodiments.
• a grate panel 20 for an open-ended grinding mill 2 comprises a sector or a part of a sector of a grate 25 of an open-ended grinding mill 2 and at least one groove portion 33 configured to open towards the grinding mill volume 28 side of the grate panel, when the grate panel 20 is mounted onto the grinding mill 2.
• grate panels 20 are shown in Figures 7, 9 and 10, and some details of grate panels 20 are shown in Figures 11 to 19.
• a grate panel 20 may comprise the whole sector or segment of the grate 25 or two or more grate panels may be configured to be mounted adjacent to one another in a radial direction along a vane 5 of a grate support element 1 and/or circumferen tially .
• each grate panel comprises two groove portions 33, one on each side 35 of the grate panel 20 configured to be di rected towards a grate panel 20 adjacent in the circumferential direction.
• one grate panel 20 may comprise one groove portion 33 for instance at one side 35 of the grate panel or at the middle area of the grate panel 20 extending from an inner end 36 of the grate panel towards an outer end 37 of the grate panel 20.
• a grate panel 20 may comprise a groove portion 33 on at least one side 35 of the grate panel and/or at least one groove portion 33 at the middle area of the grate panel 20 extending from an inner end 36 of the grate panel towards an outer end 37 of the grate panel 20.
• the groove portion 33 is preferably provided with at least one through hole opening for a mounting member, such as a bolt or similar.
• the middle area of the grate panel refers to an area of the grate panel 20 provided between the sides 35 of the grate panel configured to be directed to- wards a grate panel 20 adjacent in the circumferential direction, for instance at the centre of the grate panel 20.
• the inner end 36 of the grate panel 20 refers to the end of the grate panel 20 configured to be directed towards the middle 12 of the cross section of the grinding mill 2, when the grate panel 20 is mounted to a grind ing mill 20.
• the outer end 37 of the grate panel 20 refers to the end of the grate panel 20 configured to be directed towards the outer perimeter of the grinding mill 2, or in other words away from the middle 12 of the cross section of the grinding mill 2, when the grate panel 20 is mounted to a grinding mill 20.
• both sides 35 of the grate panel config ured to be directed towards adjacent grate panels, more particularly adjacent cir cumferentially, are provided with groove portions 33 in such a manner that groove portions 33 of two adjacent grate panels mounted side by side form together a groove portion 33 opening towards the grinding mill volume 28 side of the grate panels 20.
• Some examples of such embodiments are shown in Figures 7 and 9 to 13.
• at least one groove portion 33 may be pro vided entirely in one grate panel 20.
• At least one of the groove portions 33 has a U-shaped, V-shaped, cut-V-shaped, half-U-shaped, half-V-shaped or half-cut-V- shaped cross section, when seen from an end 36, 37 of the grate panel provided between the sides 35 of the grate panel 20.
• the U-shapes and half-U-shapes may be angular, such as in the embodiments of Figures 11, 15, 17, 18 and 19, or they may be rounded, such as in the embodiment of Figure 14.
• the cut-V-shapes and half-cut-V-shapes may be cut at both the side of the groove portion 33 configured to be directed towards the outside 34 of the grinding mill 2, in other words at the bottom of the "V", and at the side of the groove portion 33 configured to be directed towards the volume 28 of the grinding mill 2, in other words at the sides of the "V", as in the embodiment of Figure 13, or at just one of the sides, in other words just at the bottom or just at the sides of the "V”.
• the cross section of the groove portion 33 and/or vane 5 may vary, as long as they are configured to fit each other and the groove portion 33 is configured to open towards the volume 28 side of the grinding mill 2.
• both sides 35 of the grate panel 20 con figured to be directed towards adjacent grate panels 20, more particularly towards grate panels adjacent in a circumferential direction, are provided with half-U- shaped, half-V-shaped or half-cut-V-shaped groove portions 33 in such a manner that the half-U-shaped, half-V-shaped or half-cut-V-shaped groove portions 33 of two adjacent grate panels 20 mounted side by side are configured to form together a U-shaped, V-shaped or cut-V-shaped groove portion 33 opening towards the grinding mill volume 28 side of the grate panels, respectively. Examples of such embodiments are shown in Figures 7, 9, 10 and 11-13.
• the groove portion 33 may be provided as a recess in the grate panel 20. Examples of such embodiments are shown for in stance in Figures 7, 9, 10 and 11-17. According to another embodiment, the groove portion 33 may be provided by forming protrusions on both sides of the groove portion 33, either instead of or in addition to providing a recess in the grate panel 20. Examples of such an embodiment are shown in Figures 18 and 19.
• the protru- sions may be provided as an integral part of the grate panel 20, such as in the em bodiment of Figure 18, or as separate protrusion parts 43, which may be attached to the grate panel fixedly or removably, as in the embodiment of Figure 19.
• the vane 5 may be provided entirely in the groove portion 33. According to another embodiment, only a part of the cross sec- tion of the vane 5 may be provided inside the groove portion 33.
• a part of the lifter bar 32 or wear liner 39 is provided inside the groove portion 33.
• a grate support element 1 for an open-ended mill 2 comprises at least three vanes 5 extending from a distal end of the grate sup- port element, in other words from the outer perimeter 6 of the grate support ele ment 1, towards the middle end of the grate support element 1 directed towards the middle 12 of the cross section of the open-ended grinding mill 2, and an inner section 4 connecting the vanes 5 at the middle end of the grate support element 1.
• each vane 5 may be provided with at least one opening 19 for a mount- ing member configured to align with at least one of the through hole openings of a grate panel 20 according to an embodiment described in this description and ac companying figures or a combination thereof, when the grate panel 20 is mounted to the grate support element 1.
• the vanes 5 may be provided at an angle 13 in relation to cross-sectional plane 7 of the open- ended grinding mill 2 in such a manner that the middle end of the grate support element 1, in other words the inner section 4, protrudes away from a grinding mill volume 28 side of the grate support element 1.
• the grate support element 1 may further comprise an outer perimeter section 3 connecting the vanes 5 at the distal end of the grate support element 1.
• one or more grate support elements 1 are configured to form a grate support structure 22
• the inner section 4 connecting the vanes 5 at the middle end of the grate support element 1 is configured to form a ring-like inner perimeter for the grate support element, such as in the embodiments of Fig ures 3 to 6.
• the inner section 4 connecting the vanes 5 at the middle end of the grate support element 1 is configured to form a solid round centre part for the grate support element 1.
• the grate support structure 22 comprises an aperture 23 in the middle part of the grate support structure 22, the aperture 23 being defined by the inner section(s) 4 of the grate support element(s) 1, more particularly defined by inner perimeters of inner sections 4 configured to form a ring-like inner perimeter.
• the aperture 23 has a di ameter in a range of 0 to 50 percent of the diameter 24 of the outer perimeter of the grate support structure 22.
• an arrangement 40 at a grinding mill discharge end comprises at least one grate panel 20 according to an embodiment described in this description or accompanying figures or a combination of such embodiments, and at least one grate support element 1 according to an embodiment described in this description or accompanying figures or a combination of such embodiments.
• each grate support element vane 5 is preferably provided in a groove portion 33 of a grate panel 20 on the grinding mill volume 28 side of the grate panel 20, at least some of the openings 38, 19 for mounting members in the grate panel 20 and in the grate support element 1 are configured to be aligned, when a grate support element vane 5 is provided in a groove portion 33 of the grate panel 20, and the grate support element 1 is mounted to the grate panel 20 by mounting members arranged in the aligned open ings 19, 38.
• Figure 20 illustrates an example embodiment of such an arrangement at a grinding mill discharge end.
• the arrangement comprises at least one a wear liner 39 or a lifter bar 32 mounted to at least one vane 5 of a grate support element 1.
• the wear liner 39 or the lifter bar 21 comprises at least one opening 41 configured to be aligned with at least one opening 19 of the grate support element, when the wear liner 39 or the lifter bar 32 is mounted to the grate support element 1, and the wear liner 39 or the lifter bar 32 is mounted to the vane 4 of the grate support element 1 via the same mount ing member that mounts the grate support element 1 to the grate panel 20.
• grate panels 20 form a surface 42 that in terfaces with the wear liner 39 or the lifter bar 32 mounted to the vane(s) 5 in such a manner that a seamless wear surface is formed.
• the wear surface refers to the surface of the arrangement 40 directed towards the volume 28 of the grinding mill 2 and is, thus, provided in contact with the material to be ground and, therefore, subject to wear.
• Figure 21 illustrates an embodiment of a method for disassembling a discharge end 10 of a grinding mill 2.
• Such a method for disassembling a discharge end 10 of a grinding mill 2 may comprise removing 110 at least one grate panel 20 according to an embodiment described in this description and accompanying drawings or a combination of the embodiments from the outside 34 of the grinding mill 2, and removing 120 after removing the grate panel 20 or simultaneously with removing the grate panel 20 at least one grate support element 1 according to an embodiment described in this description and accompanying drawings or a com bination of the embodiments from the outside 34 of the grinding mill 2.
• the at least one grate panel 20 and the at least one grate support element 1 are removed simultaneously, this may take for instance in such a man- ner, that the grate panel 20 and the grate support element 1 are mounted to one another or they are attached fixedly to each other.
• the grate panel 20 and the grate support element 1 may be mounted to one another for instance via mounting mem bers.
• the method may further comprise remov- ing after removing the grate panel 20 or simultaneously with removing the grate panel 20 at least one wear liner 39 or at least one lifter bar 32 from the outside of the grinding mill 3.
• this may take for instance in such a manner, that the at least one grate panel 20 and the at least one wear liner 39 and/or at least one lifter bar 32 are mounted to one another or they are attached fixedly to each other.
• the grate panel 20 and the wear liner 39 and/or the lifter bar 32 may be mounted to each other for in stance via mounting members.
• the grate support element 1 may be pro- vided with a mounting flange 30 at the outer perimeter 6 of the grate support ele ment 1 configured to mount the grate support element 1 to a shell of the grinding mill 2.
• removing 120 the grate support element 1 may comprise unmounting from the outside 34 of the grinding mill 2 the mounting flange 30 of the grate support element 1 from the shell 11 of the grinding mill and lifting the unmounted grate support element 1 from the grinding mill 2.
• the mounting flange 30 may be provided as an integral part of the grate support element 1.
• the mounting flange 30 may be provided as a separate structural part and be configured to be connected to the grate support element fixedly or removably.
• Removing a grate panel 20, a grate support element 1, a wear liner 39 and/or a lifter bar 32 from the grinding mill 2 refers to lifting the grate panel 20, grate support element 1, the wear liner 39 and/or the lifter bar 32 from its place in the grinding mill and lifting it off to be refurbished, recycled or disposed.
• the grate 25 of the grinding mill 2 may be formed of 3 to 9 segments, whereby each of the segments forms a segment of the grate 25 in the range of 40 to 120 of the grate.
• a grate of a grinding mill 2 may be formed of 3 to 9 such segments mounted adjacent to one another in a circumferential manner, each inner section 4 directed towards the middle 12 of the of the cross section of the grinding mill 2, to form a round grate 25.
• the grate 25 may for instance comprise 3 segments each forming a 120-degree segment of the grate, and in another embodiment, the grate 25 may comprise 4 segments each forming a 90-degree segment of the grate 25 and so on.
• a benefit of such embodiments is that the segments 29 are lighter and easier to handle than in embodiments, where one or two segments form the grate.
• the method may further comprise stop- ping the grinding mill 2 to such a position that grate panel 20 to be removed is provided above the charge before being removed from the grinding mill 2.
• the grinding mill 2 may be stopped at a position, where the grate panel to be removed is provided at the top or close to the top of the grate 25.
• a benefit of such embodiment is that it is easier to replace a grate panel without stopping the process completely and emptying the shell 11 from slurry and ground material for the maintenance is not necessary.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Crushing And Grinding (AREA)
• Grinding Of Cylindrical And Plane Surfaces (AREA)

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