A comminution apparatus, a grate segment for a discharge grate of the comminution apparatus, and a process for comminution of material

Abstract

A comminution apparatus can include a discharge grate that is configured to have openings sized to permit comminuted material of a pre-selected size range to pass through openings of the grate. The grate can be structured to permit movement of the grate so that the size of the openings of the grate may vary during operations so that comminution media utilized in a comminution chamber that may become lodges in the openings can be dislodged for passing through the opening or being directed back into the chamber to avoid blockages of the openings. Some embodiments can utilize openings that are also tapered such that the discharge sides of the openings are wider than the comminution chamber side of the openings.

Description

A COMMINUTION APPARATUS, A GRATE SEGMENT FOR A DISCHARGE GRATE OF THE COMMINUTION APPARATUS, AND A PROCESS FOR COMMINUTION OF MATERIALFIELD

[0001] The present innovation relates to devices configured to comminute material, such as mills, presses, grinding devices, or other types of comminution apparatuses, discharge grates for comminution devices, and processes for comminution of material.BACKGROUND

[0002] Mills, presses, crushers, and other types of comminution devices used to comminute material (e.g. grind, crush, break-up, and / or pulverize the material) often include a comminution media or at least one crushing body to impact material to comminute the material. Examples of comminution devices and seals used in such devices may be appreciated from International Publication Nos. WO2022157741 and WO 2011 / 130781, U.S. Patent Nos. 84,978, 252,755, 1,225,061, 1,519,989, 1,589,302, 1,965,186, 3,833,273, 3,955,766, 3,964,717, 4,339,086, 4,369,926, 4,456,267, 4,485,974, 4,582,260, 5,203,513, 5,823,450, 6,523,767, 7,677,079 8,281,473, 8,695,904, 8,632,028, 9,321,054, 9,527,087 and U.S. Pat. App. Pub. Nos. 2014 / 0151482 and 2016 / 0101426.SUMMARY

[0003] A comminution device can often have comminuted material comminuted to a sufficiently small size for passing through an outlet or discharge grate during comminution operations. For instance, ball mills and Semi-Autogenous Grinding (“SAG”) can utilize comminution media to contact material to be comminuted during comminution operations in which large pieces of minerals or other material are comminuted into smaller pieces for being output through a discharge grate or other type of outlet.

[0004] We have determined that discharge grates that may be utilized to help size comminution materials so that only sufficiently comminuted material may be passed through the discharge plate for being output by a comminution device often have openings that become blinded, or clogged. For example, comminution media can become lodged in openings of the grate and block some of the openings through which comminuted material can pass. This can contribute toa less efficient comminution process in which yield or output of a device can be reduced. Also, it can result in material being overly comminuted to a smaller size than may be needed, which can also contribute to inefficiency in comminution operations and increase the power consumption utilized in the comminution processing.

[0005] Also, the discharge grates are often relatively heavy. Also, the material of grates is conventionally configured to use a relatively ductile material that has between a 250 and 300 Brinell hardness, which can result in the grate material becoming deformed during operation that can reduce throughput and result in higher power consumption for operation.

[0006] If a comminution device grate fractures or becomes overly blinded, the comminution device may need to be shut down to replace a grate or otherwise address the issue affecting comminution device performance. Often, such a shutdown can result in a loss of between $100,000 to $200,000 per hour that the device is shutdown due to lost operational yield. This can help exemplify the significant negative operational effects that blinding and / or higher power consumption can have on comminution device performance.

[0007] Embodiments of a discharge grate can be provided that can permit a lighter weight discharge grate that can also be less susceptible to opening deformation and / or grate breakage. Also, embodiments can be structured so that openings of the grate may adjust in size during operation so that the size of an opening may cycle between two or more sizes or geometries to help avoid comminution media becoming lodged in the openings or stuck therein so that blinding of the openings can be avoided. The openings of the grate may also be tapered so that the discharge side 20ds of each opening is wider than a comminution chamber side 20cs of the opening to help facilitate dislodgement of comminution media to avoid grate blinding. We have surprisingly found that embodiments can provide a substantially greater life of a grate (e.g. embodiments of the grate may have a wear life that is as much as 50% greater than conventional grates). Embodiments can also be lighter weight and easier to install so that installation of the grate, as well as repair work of such grates may occur more easily and quickly, which can reduce downtime. Embodiments may provide improved operational performance, along with improved operational flexibility while also requiring less maintenance and less downtime.

[0008] In some embodiments, a comminution apparatus is provided. The apparatus can include a moveable body having a comminution chamber and a discharge grate positioned adjacent the comminution chamber. The discharge grate can have discharge apertures through which comminuted material is passable to discharge comminuted material from the comminution chamber. The discharge grate can have a plurality of grate segments. Each of the grate segments can include a base member having apertures defined therein, a comminution chamber facing layer having apertures defined therein, and an intermediate layer between the comminution chamber facing layer and the base member. The intermediate layer can have apertures defined therein. The apertures of the intermediate layer can be aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define the discharge apertures of the discharge grate. An elastomeric covering can also be provided for each of the grate segments. The elastomeric covering can include a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member.

[0009] In some embodiments, the comminution chamber facing layer can be moveable laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures. For example, the intermediate layer can be moveable laterally relative to the base member to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures.

[0010] In some embodiments, the elastomeric covering can be comprised of rubber or synthetic rubber. In other embodiments, the elastomeric covering can be comprised of a polymeric material.

[0011] In some embodiments, each of the discharge apertures can be tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture. In other embodiments, the discharge apertures may not be tapered.

[0012] In some embodiments, the base member can have a first portion, a second portion, and a third portion between the first portion and the second portion and the intermediate layer can include a first intermediate layer member positioned on the first portion of the base member, a second intermediate layer member positioned on the second portion of the base member, and a third intermediate layer member positioned on the third portion of the base member. The comminution chamber facing layer can include a first comminution chamber facing member positioned on the first intermediate layer member such that the first intermediate layer member is between the first portion of the base member and the first comminution chamber facing member, a second comminution chamber facing member positioned on the second intermediate layer member such that the second intermediate layer member is between the second portion of the base member and the second comminution chamber facing member, and a third comminution chamber facing member is positioned on the third intermediate layer member such that the third intermediate layer member is positioned between the third portion of the base member and the third comminution chamber facing member.

[0013] The base member can also include other portions. For instance, the base member can include a fourth portion between the first portion and the second portion and a fifth portion between the second portion and the third portion in some embodiments. A first lifter assembly can be positioned on the fourth portion of the base member and a second lifter assembly positioned on the fifth portion of the base member.

[0014] In some embodiments, the comminution apparatus can be a Semi-Autogenous Grinding (“SAG”) mill. In other embodiments, the comminution apparatus can be configured as a ball mill or other type of mill.

[0015] A grate segment for a discharge grate of a comminution apparatus is also provided. Embodiments of the grate segment can include a base member having apertures defined therein. The base member can be comprised of metal. The grate segment can also include a comminution chamber facing layer having apertures defined therein and an intermediate layer between the comminution chamber facing layer and the base member. The intermediate layer can have apertures defined therein. The apertures of the intermediate layer can be aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define discharge apertures of the grate segment.

[0016] The grate segment can also include an elastomeric covering that includes a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member.

[0017] In some embodiments of the grate segment, the elastomeric covering is comprised of rubber, synthetic rubber, or a polymeric material.

[0018] In some embodiments of the grate segment, the comminution chamber facing layer can be moveable laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures. For example, the intermediate layer can be moveable laterally relative to the base member to facilitate selfcleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures.

[0019] In some embodiments, each of the discharge apertures of the grate segment can be tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture. In other embodiments, each of the discharge apertures of the grate segment may not be tapered. In yet other embodiment, some of the discharge apertures can be tapered while others are not tapered.

[0020] In some embodiments of the grate segment, the base member has a first portion, a second portion, and a third portion between the first portion and the second portion. The intermediate layer can include a first intermediate layer member positioned on the first portion of the base member, a second intermediate layer member positioned on the second portion of the base member, and a third intermediate layer member positioned on the third portion of the base member. The comminution chamber facing layer includes a first comminution chamber facing member positioned on the first intermediate layer member such that the first intermediate layer member is between the first portion of the base member and the first comminution chamber facing member, a second comminution chamber facing member positioned on the second intermediate layer member such that the second intermediate layer member is between the second portion of the base member and the second comminution chamber facing member, and athird comminution chamber facing member is positioned on the third intermediate layer member such that the third intermediate layer member is positioned between the third portion of the base member and the third comminution chamber facing member.

[0021] The base member can also have other portions. For instance, the base member can include a fourth portion between the first portion and the second portion and a fifth portion between the second portion and the third portion. The grate segment can also include a first lifter assembly positioned on the fourth portion of the base member and a second lifter assembly positioned on the fifth portion of the base member.

[0022] A discharge grate can also be provided. Embodiments of the discharge grate can include a plurality of the discharge grate segments that are arranged and connected to form the discharge grate.

[0023] A process for comminution of material is also provided. Embodiments of the process can include moving a body having a comminution chamber therein so that comminution media within the comminution chamber move to comminute material within the comminution chamber to form comminuted material having a size that is at or below a pre-selected size threshold. The process can also include passing the comminuted material through discharge apertures of a discharge grate positioned in fluid communication with the comminution chamber. Each grate segment of the discharge grate can include a base member having apertures defined therein, a comminution chamber facing layer having apertures defined therein, and an intermediate layer between the comminution chamber facing layer and the base member. The intermediate layer can have apertures defined therein. The apertures of the intermediate layer can be aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define the discharge apertures of the discharge grate. Each grate segment of the discharge grate can also include an elastomeric covering including a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member.

[0024] In embodiments of the process, the passing of the comminuted material through the discharge apertures can be performed such that the comminution chamber facing layer moves laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures sothat grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures while the comminuted material is passed through the discharge apertures.

[0025] In some embodiments, each of the discharge apertures can be tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture. The comminuted material can pass through the tapered discharge apertures via the passing of the comminuted material through the discharge apertures.

[0026] Embodiments of the process, apparatus, and grate segment can also include other elements or other features. For example, a process control device can be utilized to facilitate control of operations of a communication apparatus and / or an embodiment of the process.

[0027] Other details, objectives, and advantages of a comminution device, discharge grate for a comminution device, and methods of making and using the same will become apparent as the following description of certain exemplary embodiments thereof proceeds.BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Exemplary embodiments of a comminution apparatus, discharge grate for a comminution device, and methods of making and using the same are shown in the drawings included herewith. It should be understood that like reference characters used in the drawings may identify like components.

[0029] Figure 1 (which can also be referred to as FIG. 1 ) is a perspective view of a first exemplary embodiment of a comminution apparatus.

[0030] Figure 2 (which can also be referred to as FIG. 2) is a schematic view of the first exemplary embodiment of a comminution apparatus.

[0031] Figure 3 (which can also be referred to as FIG. 3) is a photograph illustrating an exemplary embodiment of a discharge grate 20 positioned to define an outlet of a comminution chamber of the first exemplary embodiment of the comminution apparatus.

[0032] Figure 4 (which can also be referred to as FIG. 4) is an exploded via of metal components of an exemplary embodiment of a grate segment 21 of the exemplary embodiment of the discharge grate 20 shown in Figure 3.

[0033] Figure 5 (which can also be referred to as FIG. 5) is a perspective view of the exemplary embodiment of the grate segment 21.

[0034] Figure 6 (which can also be referred to as FIG. 6) is a perspective view of the exemplary embodiment of the grate segment 21 with a portion of the grate segment cut away. An enlarged portion of the grate segment that is circled is shown in an enlarged view in Figure 6 as well to provide an enlarged view of this segment to better illustrate the tapering of an opening of the grate segment 21.

[0035] Figure 7 (which can also be referred to as FIG. 7) is a flow chart illustrating an exemplary embodiment of a process for comminution of material.DETAILED DESCRIPTION

[0036] Referring to Figures 1-7, a comminution apparatus 1 can include at least one crushing mechanism that is utilized to comminute material fed to the apparatus. Some embodiments of the apparatus 1 can be configured as a SAG mill or other type of mill (e.g. a ball mill).

[0037] Material can be fed to the comminution apparatus 1 via at least one inlet. The comminution apparatus 1 can be configured to comminute a material such as a mineral, an ore, rock, stone, agglomerated material, cement clinker, cement raw meal, or other type of material. After the comminution mechanism 10 has comminuted (e.g. crushed, pulverized, grinded, etc.) the material to a pre-selected size or within a pre-selected size range, the apparatus 1 can be configured to output the material that is comminuted within a comminution chamber 1 la via at least one outlet. The outlet can be defined by a discharge grate 20 that is positioned adjacent to the comminution chamber 1 la so that comminuted material can pass through openings of the grate while comminution media 11b within the chamber I la can be retained in the chamber I la.

[0038] The comminution mechanism 10 can include at least one wearable surface. The wearable surface can be configured as a liner that is attached to a body 9 that is moveable to effect comminution of material. For instance, the body9 can be rotatable so that the body 9 rotates to grind, crush, or otherwise comminute material. The body 9 that can be structured in an annular configuration (e.g. pipe, tubular, etc.) that has a central comminution chamber 1 la, defined therein. The body 9 can be rotatable so that comminution media 11b (e.g. balls, impact bodies, etc.) positioned in the comminution chamber 1 la of the body are moved within the chamber I la defined by a wearable surface attached to an inner surface of the body 9 tocomminute material (e.g. ore, rock, minerals, agglomerated material, etc.) positioned within the chamber I la. The chamber I la can be defined by a wearable surface attached to the inner surface of the body 9.

[0039] The grinding media 11b and the material fed into the chamber I la can contact each other for comminution of the material fed into the chamber I la (e.g. rock, ore, mineral, agglomerated material, etc.) as the body 9 is rotated. The grinding media and material that is to undergo comminution can also contact the wearable surface in the chamber 1 la as the body is rotated during comminution operations.

[0040] The comminution apparatus 1 can include a feed duct that is in fluid communication with a vessel that retains material or other source of material so that the material is feedable to the comminution apparatus 1 via the feed duct. The material may be solid material such as particulate material within a pre-selected size range that is to be comminuted via the comminution apparatus 1 to a smaller size and subsequently output to another process device of a plant for use of the comminuted material. The plant that includes the comminution apparatus 1 may be a cement manufacturing plant or may be another type of plant, such a mineral processing plant, a material grinding facility, or another type of plant in which a material is to be crushed or otherwise comminuted to a smaller size by the comminution apparatus 1 for use in at least one other facility process or for use in transporting the material to another location in the facility or away from the facility.

[0041] A fluid flow driving mechanism such as a fan, a blower, or a pump can be connected to the housing la of the comminution apparatus 1 to help facilitate the conveying of material into the chamber I la, comminution of the material and / or output of comminuted material from the chamber I la. For instance, the fluid flow driving mechanism can be coupled to the housing 1 or fluidly connected to chamber 1 la to facilitate the conveying of comminuted material out of the comminution chamber I la. For example, the fluid flow driving mechanism can provide fluid such as air or other type of gas into the housing la of the comminution apparatus so that material within a pre-selected size range is passed through openings of the discharge grate 20 that can be in fluid communication with the comminution chamber I la. As another example, the fluid flow driving mechanism can provide a vacuum by drawing a flow of fluid out of the housing la or out of the chamber 1 la to help facilitate the flow of comminuted material out of the housing la viathe openings of the discharge grate 20 that can be in fluid communication with the comminution chamber I la.

[0042] The discharge grate 20 can be positioned adjacent to the comminution chamber I la.The discharge grate 20 can include a plurality of grate segments 21 that are connected together to form the grate 20. The grate can be circular in shape or have another shape. The grate 20 can have a comminution chamber facing side 20a and a discharge side opposite the comminution chamber facing side 20a. The grate 20 can have a plurality of discharge apertures 20o. Each of the discharge apertures can be defined so that comminuted material that is at or below a preselected size can pass through the apertures by passing through the comminution chamber facing side of the aperture to the discharge side of the aperture 20o. The grate 20 can include a plurality of grate segments 21 that are connected together to form the grate 20. The grate segments 21 can also be referred to as grate sectors. Each grate segment 21 of the grate 20 can have a plurality of discharge apertures 20o defined therein.

[0043] As may best be appreciated from Figures 3-6, the discharge grate 20 can be formed from the connection of multiple grate segments 21 to form the discharge grate 20. The grate 20 can be circular in shape or have another type of suitable shape for being positioned adjacent to an outlet end of the comminution chamber 1 la so that the comminuted material that is at are below a pre-selected size threshold can pass out of the chamber I la via the discharge apertures 20o of the grate 20. The discharge apertures 20o can be oval shaped, irregular shaped, circular shaped, rectangular shaped, polygonal shaped, or be a combination of such shapes. Also, different discharge apertures 20o can have different shapes and lengths.

[0044] Each grate segment 21 can have an inner end 21 i and an outer end 21 o. The inner end 21 i can be positioned closer to a center of the grate as compared to the outer end 21 o. A plurality of interconnected grate segments 21 can be arranged to form a grate 20 such that each grate segment 21 has other grate segments immediately adjacent to opposite sides of the grate segment 21 between the inner end 21 i and outer end 21o of the grate segment 21.

[0045] Each grate segment 21 can include a plurality of different layers that can be interconnected to form the grate segment 21. For example, each grate segment 21 can include a base member 29 that can be positioned to be closest to a discharge side of the grate segment 21or help define the discharge side of the grate segment 21. The base member 29 can be a plate comprised of steel or other suitable metal in some embodiments.

[0046] The grate segment 21 can also include a comminution chamber facing layer 25 and an intermediate layer 27 positioned between the comminution chamber facing layer 25 and the base plate 29. The comminution chamber facing layer 25 can include a single member or can include a plurality of different members that are arranged for positioning in alignment with different portions of the base plate 29. Each member of the comminution chamber facing layer 25 can be a plate that is comprised of steel or other suitable type of metal material in some embodiments. The intermediate layer 27 can include a single member or can include a plurality of different members that are arranged for positioning in alignment with different portions of the base plate 29. Each member of the intermediate layer 27 can be a plate that is comprised of steel (e.g. laminated steel, other suitable type of steel, etc.) or other suitable type of metal material in some embodiments.

[0047] Each grate segment 21 can also include one or more lifter assemblies. For example, the grate segment can include a first lifter assembly 24 and a second lifter assembly 26. The lifter assemblies can be positioned to help facilitate positioning and installation of the grate segment 21 to form the discharge grate 20. Each lifter assembly can include multiple members that can be positioned for attachment to the base member 29.

[0048] The base member 29 can have a first end and a second end opposite its first end. A first portion 29a of the base member adjacent its first end can be sized and configured to facilitate attachment to first portion of the intermediate layer 27 and / or a first portion of a comminution chamber facing layer 25. A second portion 29c of the base member 29 adjacent its second end can be sized and configured to facilitate attachment to a second portion of the intermediate layer 27 and / or second portion of the comminution chamber facing layer 25. The base member 29 can also have an intermediate portion 29b (which can also be referred to as a third portion 29b) between its first end and its second end that can be sized and shaped to facilitate attachment to a third portion of the intermediate layer 27 and / or third portion of the comminution chamber facing layer 25. In some embodiments, the intermediate portion 29b can be spaced apart from the first portion 29a and second portion 29c so that lifter assembly portions can be defined between these portions. For example, there can be a first lifter assembly portion 29d defined between the firstportion 29a and the intermediate portion 29b of the base member 29 and there can be a second lifter assembly portion 29e defined between the intermediate portion 29b and the second portion 29c of the base member 29. The first lifter assembly portion 29d can be considered a fourth portion of the base member 29 and the second lifter assembly portion 29e can be considered a fifth portion of the base member.

[0049] The first portion 29a of the base member 29 can have a plurality of apertures 29o defined therein that can be sized to help define different discharge apertures 20o of the grate 20. The second portion 29c of the base member 29 can have a plurality of apertures 29o defined therein that can be sized to help define different discharge apertures 20o of the grate 20. At least some of these apertures 29o can be sized or arranged differently as compared to the apertures 29o of the first portion 29a. The intermediate portion 29b of the base member 29 can have a plurality of apertures 29o defined therein as well. At least some of these apertures 29o of the intermediate portion 29b can be elongated and be longer than the apertures 29o of the first portion 29a and second portion 29b.

[0050] The base member 29 can also have a first lifter assembly portion 29d and a second lifter assembly portion 29e. These lifter assembly portions can also be considered fourth and fifth portions. These portions can be defined to extend along a portion of a side of the base member 29 that is opposite its discharge side. The first lifter assembly portion 29d can be sized to receive the first lifter assembly 24 for positioning of the first lifter assembly 24 on the base member 29 so that the first lifter assembly 24 extends from adjacent the first portion 29a to the intermediate portion 29b of the base member 29. The second lifter assembly portion 29e can be sized to receive the second lifter assembly 26 for positioning of the second lifter assembly 26 on the base member 29 so that the second lifter assembly 26 extends from adjacent the second portion 29c of the base member 29 to the intermediate portion 29b of the base member 29.

[0051] The base member 29 can also include a plurality of holes 29h that are defined to facilitate attachment of the different lifter assembly elements and other layer members of the grate segment 21 to the base member 29 via fasteners (e.g. rivets, bolts, etc.). In some embodiments, the holes 29h can facilitate attachment with first and second lifter assemblies 24, 2 and intermediate layer members of an intermediate layer 27. The members of a comminution chamber facing layer 25 can be attached via fasteners to the members of the intermediate layervia different fastening holes in some configurations to permit the intermediate layer 27 and comminution chamber facing layer 25 to have a slightly greater degree of motion in the lateral direction LD when in use as discussed further herein. Alternatively, holes 29h can be alignable with holes of the members of the comminution chamber facing layer 25 for fasteners to be extendable through the holes for interconnection of the different members to the base member 29.

[0052] A covering 31 of elastomeric material can also be provided to help connect the different layers and lifter assemblies to the base member 29 as well. The covering 31 can define apertures therein that are aligned with apertures of the base member 29, intermediate layer 27, and comminution chamber facing layer 25 to define the discharge apertures 20o of the grate segment 21. The elastomeric material of the elastomeric covering 31 can be natural rubber, a synthetic rubber, or other suitable type of elastomeric material. In some embodiments, the elastomeric material of the covering 31 can be a type of polymeric material.

[0053] The intermediate layer 27 can include a plurality of different intermediate layer members. For example, there can be first intermediate layer member 27a that is sized and shaped for positioning on the first portion 29a of the base member 29 so that apertures 27o of the first intermediate layer member 27a are aligned with apertures 29o defined in the first portion 29a of the base member 29. A second intermediate layer member 27c can be sized and shaped for positioned on the second portion 29c of the base member 29 so that apertures 27o of the second intermediate layer member 27c are aligned with apertures 29o defined in the second portion 29c of the base member 29. The intermediate layer 27 can also include a third intermediate layer member 27b that is sized and shaped for positioning on the intermediate portion 29b of the base member 29 so that apertures 27o of the third intermediate layer member 27b are aligned with apertures 29o defined in the intermediate portion 29b of the base member 29. The different intermediate layer members can also have holes defined therein for being aligned with holes 29h in the different portions of the base member 29 to facilitate fastening of the different members to the base member 29.

[0054] The comminution chamber facing layer 25 can include a plurality of different comminution chamber facing members. For example, there can be first comminution chamber facing member 25a that is sized and shaped for positioning on the first intermediate layermember 27a so that apertures 25o of the first comminution chamber facing member 25a are aligned with apertures 29o defined in the first portion 29a of the base member 29 and apertures 27o defined in the first intermediate layer member 27a for defining discharge apertures 20o. A second comminution chamber facing member 25c can be sized and shaped for positioning on the second intermediate layer member 27c so that apertures 25o of the second comminution chamber facing member 25c can be aligned with apertures 27o of the second intermediate layer member 27c and are also aligned with apertures 29o defined in the second portion 29c of the base member 29 to define discharge apertures 20o. The comminution chamber facing layer 25 can also include a third comminution chamber facing member 27b that is sized and shaped for positioning on the third intermediate layer member 27b so that apertures 27o of the third intermediate layer member 27b are aligned with apertures 25o defined in the third comminution chamber facing member 25b as well as apertures 29o defined in the intermediate portion 29b of the base member 29 to define discharge apertures 29o. The different comminution chamber facing members can also have holes defined therein for being aligned with holes 29h in the different portions of the base member 29 and holes in the different intermediate layer members to facilitate fastening of the different members to the base member 29.

[0055] The first lifter assembly 24 can include a plurality of first lifter assembly members. For example, the first lifter assembly 24 can include a base member 24c that can be positioned on the first lifter assembly portion 29d of the base member 29. The base member 24c of the first lifter assembly 24 can also be considered a first member of the first lifter assembly 24. The first lifter assembly 24 can also include a second member 24b that can be positioned on the base member 24c of the first lifter assembly 24 and a third member 24a that can be positioned on the second member 24b such that the second member 24b is between the base member 24c and the third member 24a of the first lifter assembly 24. Holes defined in these different members can be aligned with holes 29h defined in the base member 29 to facilitate attachment of the first lifter assembly 24 to the base member 29 via fasteners. The first lifter assembly 24 can also include one or more sleeves 24s that can extend through different aligned holes in the base member 24c, second member 24b, and third member 24a of the first lifter assembly to help facilitate fastening of these members to the base member 29 for forming the first lifter assembly 24.

[0056] One or more lifter projections 24f can also be attached to the third member 24c or can be defined to extend from the third member 24c of the first lifter assembly 25. The lifter projections 24f can be sized and configured to facilitate manipulation of the grate segment for installation of the grate segment 21.

[0057] The second lifter assembly 26 can include a plurality of second lifter assembly members. For example, the second lifter assembly 26 can include a base member 26c that can be positioned on the second lifter assembly portion 29e of the base member 29. The base member 24c of the second lifter assembly 26 can also be considered a first member of the second lifter assembly 26. The second lifter assembly 26 can also include a second member 26b that can be positioned on the base member 26c of the second lifter assembly 26 and a third member 26a that can be positioned on the second member 26b such that the second member 26b is between the base member 26c and the third member 26a of the second lifter assembly 26. Holes defined in these different members can be aligned with holes 29h defined in the base member 29 to facilitate attachment of the second lifter assembly 26 to the base member 29 via fasteners. The second lifter assembly 26 can also include one or more sleeves 26s that can extend through different aligned holes in the base member 26c, second member 26b, and third member 26a of the second lifter assembly 26 to help facilitate fastening of these members to the base member 29 for forming the second lifter assembly 26.

[0058] The base member 29, intermediate layer 27, and comminution chamber facing layer 25 can each be separated from each other via an elastomeric member 31 that can be formed to be positioned between these layers and to provide a covering of elastomeric material over the comminution chamber facing side of the comminution chamber facing layer 25 as well as the first and second lifter assemblies 24, 26. The elastomeric covering 31 can be formed to be an integral member that is formed between the different adjacent members of the different layers, base member 29 and lifter assembly members to provide a covering that can also permit the different members to move relative to each other slightly so that the discharge apertures 20o of the grate can have variable sizes and the different members may move relative to each other while the discharge grate 20 is installed and comminuted material can pass through the discharge apertures 20o.

[0059] The elastomeric covering 31 can be comprised of natural rubber or other type of elastomeric material (e.g. synthetic rubber, etc.). The elastomeric covering 31 can be provided in different ways. For example each member of the intermediate layer 27 and comminution chamber facing layer 25 as well as the members of the first and second lifter assemblies 24 and 26 can be coated by elastomeric material to provide the elastomeric covering 31. In other embodiments, the elastomeric covering can be formed in a molding operation. Ater the different members of the lifter assemblies 24, 26, intermediate layer 27, and comminution chamber facing layer 25 and the base member 29 are positioned in a mold in spaced apart relation to each other, the mold can be closed and elastomeric material can be fed into the mold, heated, and cured to form the covering 31.

[0060] The covering 31 can be provided so that is first portion 31a, a second portion 31b, and a third portion 31c of the covering that are different portions of an integrally formed covering 31. For example, the covering 31 can include a comminution chamber facing portion 31a, an intermediate layer / comminution chamber facing layer interface portion 31b, and a base member / intermediate layer interface portion 31c. The covering 31 can also include additional portions as well. For example, the covering 31 can include lifter assembly interface portions 3 Id that are positioned between the base member 29 and the base lifter assembly member of each lifter assembly as well as lifter assembly interface portions 3 Id between different members of each lifter assembly. The elastomeric covering 31 can provide a resilient covering that can permit different members of the grate segment 21 to move relative to each other to help dislodge grinding media 11b that may become lodged in the discharge apertures 20o. The motion that may be permitted can be motion along the length and / or width of the grate segment 21. For example, there can be relative back and forth motion in a lateral direction LD (between inner 21 i and outer 21o ends of the grate segment 21). The slight relative motion that can be permitted can help permit each grate segment 21 and the grate 20 to be self-cleaning to help avoid blinding, or clogging, of the discharge apertures 20o. For example, the slight relative motion in the lateral direction LD can provide a force to act on grinding media 11b within a discharge aperture 20o to help move the media out of the aperture and back into the comminution chamber 1 la or to help the grinding media 11b pass through the discharge aperture 20o.

[0061] As noted above, each discharge aperture 20o can be defined to have a particular size. Each aperture can have a thickness that extends through the thickness T of the grate segment 21. Each aperture can also have a width D and a length L. In some embodiments, each discharge aperture 20o can have a uniform width that has the same width D at its discharge side 20ds and comminution chamber facing side 20cs. In other embodiments, the discharge apertures 20o can be tapered such that the width D of each discharge aperture 20o can be larger at a discharge side of the grate segment 21 as compared to the comminution chamber facing side.

[0062] For example, as may best be appreciated from Figure 6, the discharge side 20ds of each aperture can have a width D2 that is greater than a width DI of the aperture on its comminution chamber facing side 20cs. The tapering of the aperture through the thickness T of the grate segment 21 such that the aperture becomes wider as the aperture extends from the comminution chamber facing side of the grate segment to the discharge side of the grate segment 21 can help facilitate grinding media 11b being passed through the discharge aperture 20o. For example, if grinding media 11b becomes positioned in a discharge aperture 20o, the relative motion of different layers that can be provided via the elastomeric covering 31 along with the increasing size of the aperture as it extends from the comminution facing side of the grate segment 21 to the discharge side of the grate segment 21 can permit the grinding media to be passed through the aperture to avoid the grinding media from clogging the aperture. The grinding media 11b (e.g. steel balls, metal impact bodies, etc.) can be separated from the comminuted material for subsequent use after it is passed through the aperture as well.

[0063] Embodiments of the grate segments 21 and discharge grate 20 can be sized and configured for utilization in different type of grate configurations. For example, the grate 20 and grate segments 21 can be sized and configured for use in helical, radial or S-type discharge grates. Embodiments can be provided to avoid cracking of grates 20, plugging of discharge apertures 20o, deformation of the discharge apertures 20o and / or reduce the wear experienced by the grate 20 in operation to provide a longer life for the grate 20. Embodiments can also be lighter weight to facilitate easier installation and / or maintenance. The lightweight structure can also facilitate reduced power consumption in operation of the comminution apparatus 1. We have surprisingly found that embodiments can permit improved throughput. Some embodiments can provide an improvement of up to 15% in comminution material throughput due to theavoidance of grate blinding, or clogging, for example. This significant throughput improvement can be provided via the self-cleaning configuration of the grate segments 21, which can help avoid blinding, or clogging, of the discharge openings 20o of the grate 20.

[0064] Embodiments of the comminution apparatus 1 and grate 20 can facilitate utilization of different processes for comminution of material. An example of such a process that can be performed for comminution of material is shown in Figure 7.

[0065] In a first step SI, a body 9 of a comminution apparatus can be moved (e.g. rotated) to cause grinding media 11b within a comminution chamber 1 la to make contact with material in the comminution chamber 1 la to comminute that material. The material to be comminuted can be ore, mineral, rock, agglomerated material, or other type of material.

[0066] In a second step S2, material that has been comminuted to be at or below a pre-selected size threshold can be output from the comminution chamber 1 la by passing the comminuted material through discharge apertures 20o defined in a grate 20 that is positioned at an outlet side of the comminution chamber I la. As the comminuted material passes through the discharge apertures 20o, a comminution chamber facing layer of each grate segment 21 of the grate 20 can move relative to a base member 29 of the grate segment to help prevent one or more grinding media (e.g. steel balls, balls, impact media, etc.) from becoming stuck in a discharge aperture. For example, in the event one or more grinding media elements (e.g. a steel ball, etc.) becomes lodged in the discharge aperture 20o adjacent a comminution chamber facing side 20cs of the aperture, the comminution chamber facing layer 25 of the grate segment 21 may move in a lateral direction relative to the base member 29 to facilitate motion of the grinding media through the discharge aperture 20o so it passes out of a discharge side 20ds of the aperture and avoids blinding of the aperture. The lateral motion may alternatively work to dislodge the grinding media from the discharge aperture 20o so that it is directed back into the comminution chamber I la.

[0067] In some embodiments, the grinding media that is passed through a thickness T of a grate segment 21 as it is passed through the discharge aperture 20o of the grate 20 can be positioned in a tapered discharge aperture so that the grinding media 1 lb is able to more easily pass through the aperture as it moves through the thickness T of the grate segment 21. Examples of tapereddischarge apertures 20o and the passing of grinding media through such tapered apertures can be appreciated from the above, for instance.

[0068] In a third step S3 of the process, the comminuted material passed out of the discharge grate 20 can be utilized in a process downstream of the comminution apparatus. For example, the comminuted material can be passed to another downstream process unit for use of that material or the comminuted material can be collected for storage and subsequent use in another process of a plant.

[0069] Embodiments of the process can facilitate improved throughput for a comminution apparatus 1 via the self-cleaning action of the different grate segments 21 of the grate 20 that can be provided while the body 9 is rotated to comminute material within the comminution chamber 1 la (e.g. via comminution media 1 lb moving within the comminution chamber 1 la to contact with material to be comminuted to comminute the material). Embodiments of the process can also be utilized to provide improved operational yield while consuming less power for comminution operations and incurring less wear.

[0070] It should be appreciated that modifications to the comminution device, discharge grate, and methods of making and using the same can be made to meet a particular set of criteria for different embodiments of the filtration apparatus 1 or process. For instance, the size, shape, and thickness of different structural features of the grate 20 and / or grate segments 21 can be adapted to accommodate a particular set of design criteria. As another example, the size and shape of the discharge grate 20 can be adapted to a particular type of device geometry or other set of design criteria.

[0071] As yet another example, embodiments of the comminution apparatus 1 or comminution process can each be configured to include process control elements positioned and configured to monitor and control operations (e.g. temperature sensors, pressure sensors, flow sensors, an automated process control system having at least one work station that includes a processor, non- transitory memory and at least one transceiver for communications with the sensor elements, valves, at least one motor, and controllers for providing a user interface for an automated process control system that may be run at the work station and / or another computer device of the apparatus, etc.). It should be appreciated that embodiments can utilize a distributed controlsystem (DCS) for implementation of one or more processes and / or controlling operations of an apparatus or process as well.

[0072] As another example, it is contemplated that a particular feature described, either individually or as part of an embodiment, can be combined with other individually described features, or parts of other embodiments. The elements and acts of the various embodiments described herein can therefore be combined to provide further embodiments. Thus, while certain exemplary embodiments of a process, an apparatus, a discharge grate, and methods of making and using the same have been shown and described above, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

Claims

What is claimed is:

1. A comminution apparatus comprising: a moveable body having a comminution chamber; a discharge grate positioned adjacent the comminution chamber, the discharge grate having discharge apertures through which comminuted material is passable to discharge comminuted material from the comminution chamber; the discharge grate having a plurality of grate segments, each of the grate segments including: a base member having apertures defined therein; a comminution chamber facing layer having apertures defined therein; an intermediate layer between the comminution chamber facing layer and the base member, the intermediate layer having apertures defined therein, the apertures of the intermediate layer aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define the discharge apertures of the discharge grate; an elastomeric covering, the elastomeric covering including a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member.

2. The comminution apparatus of claim 1, wherein the elastomeric covering is comprised of rubber or synthetic rubber.

3. The comminution apparatus of claim 1, wherein each of the discharge apertures is tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture.

4. The comminution apparatus of claim 1, wherein:the base member has a first portion, a second portion, and a third portion between the first portion and the second portion; the intermediate layer includes a first intermediate layer member positioned on the first portion of the base member, a second intermediate layer member positioned on the second portion of the base member, and a third intermediate layer member positioned on the third portion of the base member; and the comminution chamber facing layer includes a first comminution chamber facing member positioned on the first intermediate layer member such that the first intermediate layer member is between the first portion of the base member and the first comminution chamber facing member, a second comminution chamber facing member positioned on the second intermediate layer member such that the second intermediate layer member is between the second portion of the base member and the second comminution chamber facing member, and a third comminution chamber facing member is positioned on the third intermediate layer member such that the third intermediate layer member is positioned between the third portion of the base member and the third comminution chamber facing member.

5. The comminution apparatus of claim 4, wherein the base member includes a fourth portion between the first portion and the second portion and a fifth portion between the second portion and the third portion.

6. The comminution apparatus of claim 5, comprising: a first lifter assembly positioned on the fourth portion of the base member and a second lifter assembly positioned on the fifth portion of the base member.

7. The comminution apparatus of claim 1, comprising: a first lifter assembly positioned on the base member.

8. The comminution apparatus of claim 7, comprising: a second lifter assembly positioned on the base member.

9. The comminution apparatus of claim 1, wherein the comminution apparatus is a Semi- Autogenous Grinding (“SAG”) mill.

10. The comminution apparatus of claim 1, wherein the comminution chamber facing layer is moveable laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures.

11. The comminution apparatus of claim 10, wherein the intermediate layer is moveable laterally relative to the base member to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures.

12. The comminution apparatus of claim 10, wherein each of the discharge apertures is tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture.

13. A grate segment for a discharge grate of a comminution apparatus, the grate segment comprising: a base member having apertures defined therein, the base member comprised of metal; a comminution chamber facing layer having apertures defined therein; an intermediate layer between the comminution chamber facing layer and the base member, the intermediate layer having apertures defined therein, the apertures of the intermediate layer aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define discharge apertures of the grate segment; an elastomeric covering, the elastomeric covering including a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member.

14. The grate segment of claim 13, wherein: the base member has a first portion, a second portion, and a third portion between the first portion and the second portion; the intermediate layer includes a first intermediate layer member positioned on the first portion of the base member, a second intermediate layer member positioned on the second portion of the base member, and a third intermediate layer member positioned on the third portion of the base member; and the comminution chamber facing layer includes a first comminution chamber facing member positioned on the first intermediate layer member such that the first intermediate layer member is between the first portion of the base member and the first comminution chamber facing member, a second comminution chamber facing member positioned on the second intermediate layer member such that the second intermediate layer member is between the second portion of the base member and the second comminution chamber facing member, and a third comminution chamber facing member is positioned on the third intermediate layer member such that the third intermediate layer member is positioned between the third portion of the base member and the third comminution chamber facing member.

15. The grate segment of claim 14, wherein the base member includes a fourth portion between the first portion and the second portion and a fifth portion between the second portion and the third portion, and the grate segment also comprises: a first lifter assembly positioned on the fourth portion of the base member and a second lifter assembly positioned on the fifth portion of the base member.

16. The grate segment of claim 13, wherein the elastomeric covering is comprised of rubber or synthetic rubber.

17. The grate segment of claim 13, wherein each of the discharge apertures of the grate segment is tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture.

18. The grate segment of claim 13, wherein the comminution chamber facing layer is moveable laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures.

19. A process for comminution of material, comprising: moving a body having a comminution chamber therein so that comminution media within the comminution chamber move to comminute material within the comminution chamber to form comminuted material having a size that is at or below a pre-selected size threshold; passing the comminuted material through discharge apertures of a discharge grate positioned in fluid communication with the comminution chamber, each grate segment of the discharge grate including: a base member having apertures defined therein; a comminution chamber facing layer having apertures defined therein; an intermediate layer between the comminution chamber facing layer and the base member, the intermediate layer having apertures defined therein, the apertures of the intermediate layer aligned with the apertures of the comminution chamber facing layer and the apertures of the base member to define the discharge apertures of the discharge grate; and an elastomeric covering, the elastomeric covering including a first portion positioned on the comminution chamber facing layer, a second portion between the comminution chamber facing layer and the intermediate layer, and a third portion between the intermediate layer and the base member; and wherein the passing of the comminuted material through the discharge apertures is performed such that the comminution chamber facing layer moves laterally relative to the intermediate layer to facilitate self-cleaning of the discharge apertures so that grinding media that is lodgeable within the discharge apertures is passable through the discharge apertures to avoid blinding of the discharge apertures while the comminuted material is passed through the discharge apertures.

20. The process of claim 19, wherein each of the discharge apertures is tapered such that a discharge side of the discharge aperture is larger than a comminution chamber side of the discharge aperture.

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