CN218250601U

CN218250601U - Wear-resistant lining element and grinding machine

Info

Publication number: CN218250601U
Application number: CN202220066044.4U
Authority: CN
Inventors: I·范齐尔; C·尼科尔斯
Original assignee: Metso Outotec Finland Oy
Current assignee: Metso Finland Oy
Priority date: 2021-01-18
Filing date: 2022-01-11
Publication date: 2023-01-10
Anticipated expiration: 2032-01-11
Also published as: EP4029609A1; CN114798094A; WO2022152667A1

Abstract

A wear-resistant liner element (30, 30 ') for a grinding mill is provided with an expandable ejector unit (50), the expandable ejector unit (50) being arranged between an outer surface of the wear-resistant liner element (30, 30') and an opposed inner surface of a housing or end wall of the mill. The ejector unit (50) has a first portion for abutting or engaging with the outer surface of the wear-resistant liner element (30, 30 ') and a second portion for abutting or engaging with the inner surface of the shell or end wall, and the ejector unit (50) is operable to increase the spacing between its first and second portions to increase the spacing between the outer surface of the wear-resistant liner element (30, 30') and the inner surface of the shell or end wall. The present disclosure also relates to a grinding mill.

Description

Wear-resistant lining element and grinding machine

Technical Field

The present invention relates to a wear-resistant liner element for a grinding mill, a grinding mill comprising such wear-resistant liner element, a method of removing at least one wear-resistant liner element from a grinding mill, and the use of an expandable ejector unit, such as a lifting bag or the like, for removing a wear-resistant liner element from a grinding mill.

Background

Grinders are used to grind ore or primary crusher products.

One type of grinding machine comprises a drum in which the material to be ground, i.e. the charge, is ground by rotating the drum. The drum may be oriented horizontally or vertically. The charge is ground by the collision of the charge portions with each other and with the particles surrounding and impacting the charge.

In certain types of horizontal drum mills, known as ball mills or pebble mills, balls of hard material are introduced into the drum with the charge. As the drum rotates, the charge is also ground by the impact from the balls.

Another type of mill comprises a vessel in which a stirrer is arranged. In the vessel there is provided a grinding medium such as steel balls or ceramic or natural pebbles. Water and the material to be ground are fed into the container. By means of a rotating stirrer, the charge is agitated, so that the grinding media grind the material to be ground by friction (abrasion) and abrasion (abrasion). This type of mill can be oriented either vertically or horizontally.

The internal components of such mills are subject to severe wear during the grinding process. Thus, the internal components of the grinding mill may be covered with some sort of wear protection, such as wear-resistant lining elements. In a vertical mill, the inner peripheral surface of the (substantially cylindrical) shell may be provided with wear-resistant lining elements. In a horizontal mill, material to be ground (e.g. lumps of ore) is fed into one end of the mill and ground product is removed from the other end, and both the (substantially circular) inlet end wall and the (substantially cylindrical) inner peripheral surface of the housing and the (substantially circular) discharge end wall may be provided with wear resistant lining elements.

In addition to protecting the mill shell from wear caused by impact and friction of the mill charge, such wear resistant liner elements can also be operated to lift and tumble mill contents in the necessary manner to produce a grinding action. To accomplish this, the mill liner profile must be made of a highly wear resistant material and employ the correct geometry to help determine the height of the mill charge and how the material is ground.

In the past, grinding mills have typically been lined with various steel or iron alloys, cast metal liners such as manganese steel or chilled cast iron, depending on the characteristics of the material to be ground and the particular classification of the intended service of the machine. Manganese steels combine extremely high toughness with high wear resistance.

With advances in material technology and design skills, there are currently some alternatives to metal liners. Rubber compounds and composites have been developed to protect mill casings from wear, while new cast alloys and wear plates may be incorporated into the rubber to resist high impact friction. Rubber steel composite (Polymet) and metal lining are common in primary mills.

Typically, wear-resistant lining elements wear and deform due to the large pressure and impact load forces they transmit. It is common to use a backing behind the wear-resistant liner element-usually a rubber backing, as is common with vertical mills with Polyurethane (PU) -to provide further protection as well as corrosion protection and to prevent irregularities, thereby facilitating contact between the outward-facing surface of the wear-resistant liner element and the inward-facing surface of the mill shell, i.e., the shell and the end wall. In fact, the loading forces must be transferred from the mill structural component protected by the wear-resistant liner element to the wear-resistant liner element, for which a close contact between the back face of the wear-resistant liner element and the inner surface of the shell or end wall is required. The rubber backing is typically bonded to the inwardly facing surface of the mill housing by an adhesive, such as a cured adhesive.

The wear-resistant lining elements are replaced periodically, for example at intervals of 4, 12, 18 or 24 months. It is cumbersome to replace the wear-resistant lining elements. Generally, the shell liner is composed of a plurality of metal segments (e.g., made of manganese steel) that are installed in end-to-end relationship with their flat ends nearly touching, usually with a small gap between the ends. After a certain period of operation, these segments may be difficult to remove: on the one hand, the partial charge combines with the slurry in the mill to produce a cement-like mass which will enter between the liners and make removal of the liners more difficult. Small grinding media or small pieces of grinding balls that have become loose may also enter between the liners. On the other hand, as the liner is subjected to large impacts, metal flow (linear strain) occurs along the length of the liner, wherein linear expansion of the liner segments generates large pressures at the abutting flat end faces, which tends to lock the liner segments in place and make them difficult to remove for maintenance. The wear-resistant lining elements are thus removed one by one using a rock crusher, i.e. a hydraulic or pneumatic hammer, which is driven behind the wear-resistant lining elements.

In large mills, it is easy to replace more than 1000 wear lining elements (hundreds for the shell and hundreds for the end walls). Existing methods for removing and replacing wear-resistant lining elements, also known as "re-lining", are time consuming, often requiring several days to complete. This means down time and lost production for the mill operator.

Furthermore, these wear-resistant lining elements are large and heavy and difficult to handle in a safe and reliable manner. Different types of tools and lifting devices have been provided in order to be able to handle the lining elements in a manner safe for maintenance personnel. Removal of wear-resistant lining elements is also a dangerous task requiring the use of hot work.

An exemplary grinding mill shell liner element is disclosed in US4,231,528. US 2005/0116077A1 describes a shell liner profile. An exemplary grinding mill end liner is known from US 2,893,650, and AU 2014/201893A1 discloses an apparatus and method for treating an end wall liner element of a grinding mill.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is an object of the present invention to facilitate the removal of worn liner elements from a grinding mill.

In order to achieve this object, the invention provides a wear-resistant lining element for a cylindrical housing of a horizontal or vertical grinding mill according to the invention, and a wear-resistant lining element for an end wall of a horizontal grinding mill according to the invention.

According to the invention, the wear-resistant lining element is provided with an expandable ejector unit arranged between the outer surface of the wear-resistant lining element and the opposite inner surface of the casing or end wall of the grinding mill. The ejector unit has a first portion for abutting or engaging with the outer surface of the wear-resistant lining element and a second portion for abutting or engaging with the inner surface of the shell or end wall, and is operable to increase the spacing between the first portion and the second portion, thereby increasing the spacing between the outer surface of the wear-resistant lining element and the inner surface of the shell or end wall.

The ejector unit is mounted in its undeployed state between the outer surface of the wear-resistant lining element and the opposite inner surface of the housing or end wall. In other words, the ejector unit is pre-mounted between the wear-resistant lining element and the opposite surface of the housing or end wall. If it is time to remove the wear-resistant lining element, the ejector unit is operated to expand it, prying the wear-resistant lining element off its support.

Thus, the present invention does not require the use of hydraulic/pneumatic hammers to assist in the removal of worn wear-resistant lining elements from the grinding mill and does not require workers to operate directly in the area of the wear-resistant lining elements.

The utility model discloses still make the down time during the maintenance show and reduce.

Thus, the present invention will improve overall shutdown efficiency and effectiveness for all relining operations.

According to an embodiment of the invention optional further features of a wear lining element for a grinding mill of the invention are recited.

The wear-resistant lining element for the shell may have a substantially elongated shape with a profiled cross-section. The wear-resistant lining element for the end wall may substantially have the shape of a segment of a circle or a part thereof.

The ejector unit may be expanded pneumatically or hydraulically. In principle, mechanically operable ejector units, such as high-power springs or servo-driven link arms which are released by remote control, are also conceivable.

The ejector unit may be operable to increase the volume of the ejector unit. In particular, the expandable ejector unit may comprise a lifting bag.

The hoisting bag is capable of lifting loads of several tons, wherein a hoisting bag with a capacity of e.g. eight tons may be used for the purpose of the invention (currently used wear-resistant lining segments for grinding mills have a weight of up to 8 tons). The lift bag is typically inflated using compressed air, and in some cases water or mud.

Compared to other types of jacking equipment (jacking equipment), lift bags have major advantages such as small insertion height, fast operation speed, etc. They are also lightweight and require little maintenance.

The hoisting bag to be used according to the invention can be made of one or more layers on each side. Suitable materials for the one or more layers include aramid with neoprene (Kevlar) and woven steel. The surface of the lift bag may be configured to provide a non-slip effect.

The lifting bag works according to the following principle: force (F) = pressure (P) x area (a). It would therefore be advantageous to provide a lifting bag having a sufficiently large surface area to apply the required force to the wear-resistant liner element to be removed.

Suitable high pressure inflatable lifting bags are available on the market, for example from MatJack for lifting, moving, unfolding and securing applications.

The wear-resistant lining element may also comprise means for operating the ejector units, which means comprise, for example, hydraulic or pneumatic lines or hoses extending to each ejector unit in the grinding mill.

The ejector unit may be arranged in the region of an edge of the wear-resistant lining element. The removal of the wear-resistant lining element is thereby easier than in the case where the ejector unit is to be arranged in the central region of the wear-resistant lining element: when activated, the ejector unit acts on the edge portion of the wear-resistant lining element to "peel" the wear-resistant lining element off the underlying surface of the shell or end wall.

The wear-resistant lining element may comprise a cavity or groove in the outer surface to accommodate the expandable ejector unit. The groove serves as an ejector unit engagement section. In other embodiments, the ejector unit may be mounted between the rear or outer surface of the wear-resistant lining element and the opposite surface of the shell without the need to form such a groove in the rear face of the segment.

According to the invention, the ejector unit is a part that can be operated pneumatically or hydraulically.

According to the invention, the ejector unit is a component that can be operated to increase its volume.

The invention also provides a grinding mill according to the invention, wherein at least one wear-resistant lining element is provided with an expandable ejector unit, which ejector unit is arranged between the outer surface of the wear-resistant lining element and the opposed inner surface of the shell or end wall. The ejector unit has a first portion for abutting or engaging with the outer surface of the wear-resistant lining element and a second portion for abutting or engaging with the inner surface of the shell or end wall, and is operable to increase the spacing between the first portion and the second portion, thereby increasing the spacing between the outer surface of the wear-resistant lining element and the inner surface of the shell or end wall.

The wear-resistant lining element of the grinding mill may comprise one or more of the features described above for the wear-resistant lining element and the expeller unit.

The grinding mill may further comprise means for operating the ejector units, for example comprising hydraulic or pneumatic lines or hoses extending to each ejector unit in the grinding mill.

The wear-resistant liner elements may be supported end-to-end in the longitudinal direction of the shell and/or in a circular array on the inner surface of the at least one end wall, and a series of a plurality of wear-resistant liner elements is arranged such that one, more or all wear-resistant liner elements in the series are provided with an ejector unit.

In principle one lifting bag may be installed to act on a plurality of (adjacent) wear-resistant lining elements. A load distributor plate may then be provided so that the lifting bag is not affected by any potential gaps between the wear-resistant lining elements, or if one wear-resistant lining element falls off before the other.

In the grinding machine, a backing such as a rubber backing may be provided on the inner surface of the shell or end wall, which faces the outer surface of the wear-resistant lining element, to provide foundation protection and prevent unevenness. The rubber backing may be bonded to the inner surface of the housing or end wall in its known manner by use of a suitable adhesive.

The grinder may also be associated with a control unit to control the activation of the one or more ejector units, e.g. from a remote location, e.g. by a wireless connection.

The present invention also provides a method of removing at least one wear-resistant lining element from a grinding mill according to the present invention, wherein the wear-resistant lining element (30, 30 ') is attached to the inner surface of the shell or end wall of the grinding mill, the outer surface of the wear-resistant lining element (30, 30') facing the inner surface of the shell or end wall. The method comprises the following steps: arranging an expandable ejector unit between an outer surface of the wear-resistant lining element and an opposite inner surface of the shell or end wall, the ejector unit having a first portion for abutting or engaging the outer surface of the wear-resistant lining element and a second portion for abutting or engaging the inner surface of the shell or end wall; and operating the ejector unit to increase the spacing between the first and second portions to increase the spacing between the outer surface of the wear liner element and the inner surface of the shell or end wall.

According to the invention, the wear-resistant lining elements are arranged end-to-end along the length of the shell in at least one row, and in each row a critical wear-resistant lining element is removed, for example by means of a thermal spray gun, before activating the ejector unit or ejector units in the row.

If the wear-resistant liner elements are arranged in a circular array on the inner surface of at least one end wall, one critical wear-resistant liner element in the array may be removed, for example by means of an associated ejector unit, in order to relieve any stress prior to removing the remaining segments in the array by activating the respective ejector unit or units or by other means. In an embodiment, only the critical wear-resistant lining elements are removed with the ejector unit, while the remaining elements in the array on the end wall are removed by the replacement means.

Ejector units for individual segments in a row or array may be activated individually to remove segments individually along the housing or end wall; or a plurality of ejector units may be activated simultaneously to remove a plurality, possibly a plurality, of adjacent wear lining elements simultaneously.

If multiple rows of liners are provided, as is often the case in grinding mills, multiple rows of segments are typically removed beginning with a row of liner elements in the lower portion of the mill.

After the removal of the row of elements is completed, the removed wear-resistant lining elements may be removed from the grinding mill in any known manner.

According to the present invention, the present invention covers the use of an expandable ejector unit, such as a lifting bag, for removing a wear-resistant liner element from a grinding mill, wherein the wear-resistant liner element is attached to an inner surface of a shell or end wall of the grinding mill, an outer surface of the wear-resistant liner element facing the inner surface of the shell or end wall, the ejector unit is arranged between the outer surface of the wear-resistant liner element and the opposite inner surface of the shell or end wall, and the ejector unit has a first portion for abutting against or engaging the outer surface of the wear-resistant liner element, and a second portion for abutting against or engaging the inner surface of the shell or end wall, and the ejector unit is operable to increase the spacing between the first portion and the second portion, thereby increasing the spacing between the outer surface of the wear-resistant liner element and the inner surface of the shell or end wall.

Finally, the invention also relates to a wear-resistant lining element for a grinding mill according to the invention. The wear-resistant liner element according to the present invention comprises an ejector unit engagement section configured to receive or accommodate an expandable ejector unit.

The wear-resistant liner element according to the present invention and the expandable ejector unit configured to be received or accommodated may comprise any of the above features or a combination thereof.

Furthermore, the ejector unit engaging section may e.g. be a groove or a cavity in the outer surface of the wear-resistant lining element to accommodate an expandable ejector unit. The recess or cavity may have a temporary, easily removable material inserted therein during installation. When it is desired to install the ejector units, the insert may be removed or destroyed in situ in order to make room for the ejector units.

The shape of the recess in the wear-resistant lining element may be designed to match the shape of an ejector unit, such as a lifting bag. The matching shape may provide a form fit between the ejector unit and the wear-resistant lining element.

Drawings

The above and other objects, features and advantages of the present invention will be better understood from the following illustrative and non-limiting detailed description of preferred embodiments thereof, made with reference to the accompanying drawings, wherein like reference numerals will be used for like elements, in which:

fig. 1 schematically shows a shell of a horizontal grinding mill equipped with wear-resistant lining elements;

FIG. 2a shows an exemplary shell liner element for a grinding mill and FIG. 2b shows an exemplary endwall liner element for a grinding mill;

figure 3a is a schematic view of a shell liner element according to an embodiment of the present invention;

FIG. 3b shows the lift bag in a deflated state;

fig. 4a and 4b show a wear-resistant lining element with a lifting bag in perspective view and from the side;

fig. 5a and 5b show the wear-resistant lining element with the lifting bag inflated, again in perspective view and from the side; and

fig. 5c shows the lifting bag in an inflated state.

Detailed Description

Fig. 1 schematically shows a grinding mill. The sole purpose of this diagram is to explain the basic working principle of the grinding machine, which should not be understood to mean any limitation of the invention. The mill shown here is a horizontal mill designed for grinding, for example, raw ore (ground ore) and generally comprising a cylindrical housing made of steel supported for rotation about a horizontal axis, and a vertical end wall bounding a charge. The utility model is also suitable for a vertical mill.

The inner peripheral surface of the housing and the inner surface of the end wall, particularly the inner surface of the discharge end wall, are subjected to significant wear and wear. In order to control the movement of the ore in the mill and to protect the steel shell and the end walls from wear and corrosion, wear resistant lining elements are mounted on the steel shell and the end walls.

Fig. 1 shows that the inlet end wall, the cylindrical part of the casing and the discharge end wall of the mill are each provided with wear-resistant lining elements. The cylindrical shell is lined by a plurality of substantially flat liner members (e.g., made of manganese steel) which are mounted in end-to-end relationship with their flat ends nearly in contact, typically with a small gap between the ends, and which are supported in a cylindrical array by being individually bolted to the inner surface of the mill shell. After a certain period of operation, these wear-resistant lining elements may be difficult to remove: on the one hand, a portion of the charge combines with the mud within the mill, creating a cement-like mass that will get between the liners and make removal of the liners more difficult. Small grinding media or small pieces of grinding balls that have become loose may also enter between the liners. On the other hand, as the liner is subjected to large impacts, metal flow (linear strain) occurs along the length of the liner, with linear expansion of the liner elements creating large pressures at the abutting flat end faces, which tend to lock the liner segments in place and make them difficult to remove for maintenance.

Fig. 2a shows one of the substantially flat liner elements 30 (also referred to as "casing liner") for the inner periphery of the casing. The wear-resistant lining element shown here has a specific profile to assist in moving the material to be ground within the grinding mill, but this profile is not essential to the invention and other profiles may be used.

The shell liners may be alternately spaced by lifting bars (lifter-bar) for lifting ore to the top of the rotating shell or drum where it tumbles under gravity from the top to the bottom of the rotating shell or drum where it is crushed or reduced in size. On the other hand, the liner itself may be configured with raised ribs to act as lifters (lifters) when lifting ore.

The inlet and outlet end walls are provided with wear-resistant lining elements 30'. Since the end wall is substantially cylindrical, the wear-resistant lining element 30' for the end wall ("end wall lining") generally has the shape of a segment of a circle. Although the endwall liner in fig. 2b is made of two parts, other configurations may be employed in this regard.

In the operating condition of the mill, a rubber backing (not specifically shown) will be provided between the outer surface of the wear-resistant liner element 30, 30' and the inwardly facing circumferential surface of the shell or end wall. The rubber backing is provided in its known manner to form a base protection and prevent irregularities to assist contact between the outwardly facing surfaces of the wear-resistant lining elements 30, 30' and the inwardly facing surfaces of the shell and end walls.

Wear-resistant lining elements are usually bolted to the shell and the end walls. For this purpose, the wear-resistant lining element can be equipped with a through-hole, a threaded insert or a threaded bushing.

It is apparent that the casing liner and endwall liner are subject to severe wear and tear due to the high impact loads and friction that continues during grinding operations, thus requiring periodic replacement of the liner.

In order to facilitate removal of the wear-resistant lining elements from the shell or the end wall and replacement with new wear-resistant lining elements, at least some of the wear-resistant lining elements 30, 30 'are provided with expandable ejector units (not shown in fig. 1, 2a and 2 b), respectively, which are arranged between the outer surface of the wear-resistant lining elements 30, 30' and the opposite inner surface of the shell or the end wall. The ejector unit is expandable to increase the spacing between the outer surface of the wear-resistant liner element 30 and the inner surface of the shell or end wall. The ejector unit is mounted in its undeployed state between the outer surface of the wear-resistant lining element and the opposite surface of the housing or the end wall. In other words, the ejector unit is pre-mounted between the wear-resistant lining element 30 and the opposite surface of the casing or end wall.

If it is time to remove the wear-resistant lining element 30, 30', the ejector unit 50 is operated to expand it to lever the wear-resistant lining element 30, 30' off its support.

Thus, the present invention does not require the use of hydraulic/pneumatic hammers to assist in the removal of worn wear-resistant lining elements from the grinding mill and avoids the need for workers to be present in the area of the wear-resistant lining elements themselves. On the other hand, this will significantly reduce the down time during maintenance.

The invention comprises an ejector unit that can be expanded in different ways, for example pneumatically or hydraulically. One practical embodiment of an expandable ejector unit is an inflatable lifting bag 50, which is also used in the embodiment shown in fig. 1-5. The lifting pockets 50 are arranged between the outer surface of the wear-resistant lining elements 30, 30' and the opposite inner surface of the mill shell or end wall. The lifting bag 50 has opposed major surfaces, a first major surface abutting or engaging the outer surface of the wear-resistant liner element 30, 30' and a second major surface abutting or engaging the inner surface of the shell 40. The lift bag 50 is installed in its deflated state. When the lifting bag 50 is operated to inflate, the volume of the lifting bag 50 increases and the spacing between the first and second surfaces increases, thereby pushing the wear-resistant lining element 30, 30 'away from the inner surface of the shell or end wall, thereby removing the wear-resistant lining element 30, 30' from the shell or end wall. Thus, the force exerted by the lift bag 50 helps break up any material, such as cement-like materials or grinding ball pieces, that has deposited in the gaps between the liner elements over time, and keeps the liner elements stuck.

Fig. 3a shows a wear-resistant liner element 30, 30' for a grinding mill, which currently does not have a lifting bag 50. The wear-resistant liner element 30, 30' of the present embodiment differs from similar wear-resistant liner elements of the prior art in that the back face of the wear-resistant liner element 30, 30' contains a cavity or recess 60 therein which is large enough to accommodate the deflated lifting bag 50 when the wear-resistant liner element 30, 30' is mounted on a grinding machine.

Fig. 3b shows an exemplary embodiment of a lifting bag, which is commercially known as "MatJack" for lifting, moving, unfolding and securing applications. The lifting bag is capable of lifting a predetermined weight, such as 6 tons, if inflated with air at a corresponding pressure. In the present embodiment the lifting bag has an approximately square shape, but the lifting bag for the invention may also have other shapes, such as rectangular or circular.

The recesses 60 in the lifting pocket 50 and the wear-resistant liner elements 30, 30 'have matching shapes, for example, to provide a form fit between the lifting pocket 50 and the wear-resistant liner elements 30, 30'. In this embodiment, the lifting bag 50 has four lugs 51 integrally molded to its edge for lifting or attachment to a fixture. In this embodiment, the grooves 60 in the back face of the wear-resistant lining element 30, 30' comprise corresponding cut-outs 61.

In other embodiments, the lifting bag 50 may be installed between the rear surface of the wear-resistant liner element 30, 30 'and the opposite surface of the shell 40 without the need to form such a groove 60 in the rear face of the wear-resistant liner element 30, 30'.

The lift bag 50 works according to the following principle: force (F) = pressure (P) x area (a). Thus, the surface area of the lift bag 50 should be large enough to generate the required force. The surface area of the lifting pocket 50 relative to the surface area of the wear-resistant lining element 30, 30', i.e. the surface area of the rear or outer surface of the wear-resistant lining element, should suitably be a sufficient percentage, as shown in fig. 3 a. In the illustrated embodiment, the surface area of the lifting pocket 50 may be up to about one-fourth the surface area of the rear or outer surface of the wear-resistant liner element 30, 30', for example.

Fig. 4a and 4b show the wear-resistant lining element 30, 30' in perspective view and from the side, the lifting bag 50 being mounted in the above-mentioned recess 60. Fig. 5a and 5b show the wear-resistant lining element 30, 30' again in perspective view and from the side with the lifting bag 50 inflated. An exemplary lift bag 50 is also shown in an inflated state (fig. 5 c). Fig. 5a and 5b are partial views of the wear-resistant lining element 30, 30' and the shell or end wall from the side and in perspective in a state in which the lifting bag 50 located between the outer surface of the wear-resistant lining element 30, 30' and the inner surface of the shell or end wall has been inflated and has separated the wear-resistant lining element 30, 30' from the shell or end wall.

To operate the ejector unit, i.e. the lifting bags 50, pneumatic lines or hoses (not shown) extend from each lifting bag in the mill towards a source of compressed air (not shown). The lifting bag 50 in fig. 3b and 5c comprises a corresponding connector 52 for a pneumatic line. Pneumatic lines from multiple lift bags 50 may be combined through respective manifolds. A control unit (not shown), such as a push button, deadman, or joystick controller, is provided to control the supply of compressed air to inflate one or more of the lift bags 50, either individually or simultaneously.

Considering the mill as a whole, one or more wear-resistant lining elements in each row (for the shell) or array (for the end wall) are provided with an ejector unit. In one embodiment only one wear-resistant lining element in each row or array is provided with an ejector unit, or even only one wear-resistant lining element in the shell or an end wall. Once the wear-resistant lining element is removed, the remaining wear-resistant lining element falls off or at least is more easily removed.

In principle, the lifting pockets 50 for the individual segments 30, 30 'in a row can be activated one by one in order to remove the segments 30, 30' one by one along the length of the housing and along the perimeter of the end walls. It is also contemplated that multiple lift bags 50 may be activated simultaneously to remove multiple, and possibly multiple, adjacent wear-resistant liner elements 30, 30' simultaneously. In any event, the process will continue until all of the elements 30, 30' in a row have been dismantled and are ready for removal from the mill.

The detached wear-resistant lining elements 30, 30' are then removed from the mill in any known manner.

Each wear-resistant lining element 30, 30' shown in fig. 1 may be provided with a lifting bag 50. In a practical embodiment, one wear liner element 30, 30 'of a row of wear liner elements 30, 30' will be provided with an expandable ejector unit, for reasons which will be explained further below.

In the shown embodiment, the lifting pockets 50 are provided in the area of the top edge of the respective wear-resistant lining element 30, 30'. The removal of the wear-resistant lining elements 30, 30 'is thereby easier than if the lifting bag 50 would be arranged in the central area of the wear-resistant lining elements 30, 30': when inflated, the lifting bag 50 then acts on the upper portion of the wear-resistant lining element 30, 30 'to "peel" the wear-resistant lining element 30, 30' off the underlying surface of the shell or end wall.

The utility model discloses will improve the shut down efficiency and the efficiency to whole relining work again comprehensively.

Although an embodiment of the present invention has been described with reference to fig. 1 to 5c, the scope of the present invention is not limited to the embodiment, but is defined by the appended claims. Various modifications are included within the scope.

For example, in the present embodiment, each lifting pocket 50 is associated with one wear-resistant liner element 30, 30'. In principle, it is conceivable to associate the lifting bag 50 with a plurality, i.e. two, three or more adjacent wear-resistant lining elements 30, 30', which elements will then be acted upon simultaneously.

Claims

1. A wear-resistant lining element for a cylindrical shell of a horizontal or vertical grinding mill,

wherein the grinding mill comprises a cylindrical shell configured such that at least one wear-resistant lining element (30) can be attached to the cylindrical shell, the outer surface of the wear-resistant lining element (30) facing the inner surface of the shell,

it is characterized in that the preparation method is characterized in that,

the wear-resistant lining element (30) is provided with an expandable ejector unit (50), the expandable ejector unit (50) being arranged between an outer surface of the wear-resistant lining element (30) and an opposite inner surface of the shell, and

the ejector unit (50) has a first portion for abutting or engaging with the outer surface of the wear-resistant lining element (30) and a second portion for abutting or engaging with the inner surface of the shell, and the ejector unit (50) is operable to increase the spacing between its first and second portions to increase the spacing between the outer surface of the wear-resistant lining element (30) and the inner surface of the shell.

2. A wear-resistant lining element according to claim 1, characterized in that the wear-resistant lining element (30) has a flat, elongated shape.

3. A wear-resistant lining element for an end wall of a horizontal grinding mill,

wherein the grinding mill comprises a cylindrical housing rotatable about a horizontal axis, and vertical end walls for bounding the charge, at least one of the end walls being configured such that at least one wear-resistant lining element (30 ') can be attached thereto, an outer surface of the wear-resistant lining element (30') facing an inner surface of the end wall,

it is characterized in that the preparation method is characterized in that,

the wear-resistant lining element (30') is provided with an expandable ejector unit (50), the expandable ejector unit (50) being arranged between an outer surface of the wear-resistant lining element (30) and an opposite inner surface of the end wall, and

the ejector unit (50) has a first portion for abutting or engaging with the outer surface of the wear-resistant lining element (30 ') and a second portion for abutting or engaging with the inner surface of the end wall, and the ejector unit (50) is operable to increase the spacing between its first and second portions to increase the spacing between the outer surface of the wear-resistant lining element (30') and the inner surface of the end wall.

4. A wear-resistant lining element according to claim 3, characterized in that the wear-resistant lining element (30') has the shape of a circle segment or a part of a circle segment.

5. A wear-resistant lining element according to claim 3, characterized in that the ejector unit (50) can be operated pneumatically or hydraulically.

6. A wear-resistant lining element according to claim 3, characterized in that the ejector unit (50) is operable to increase its volume.

7. A wear-resistant lining element according to claim 6, characterized in that the ejector unit (50) comprises a lifting bag.

8. A wear-resistant lining element according to any one of claims 3 to 7, characterized by further comprising operating means of the ejector unit (50).

9. A wear-resistant lining element according to claim 8, characterized in that the operating means comprise hydraulic or pneumatic lines extending to each expeller unit (50) in the grinding mill.

10. A wear-resistant lining element according to any one of claims 3 to 7, characterized in that the ejector unit (50) is arranged in the region of an edge of the wear-resistant lining element (30, 30').

11. A wear-resistant lining element according to any one of claims 3 to 7, characterized in that the outer surface of the wear-resistant lining element (30, 30') is configured to receive or accommodate an expandable ejector unit (50).

12. A wear-resistant lining element according to claim 10, characterized in that the outer surface of the wear-resistant lining element (30, 30') contains a cavity or groove (60) therein to accommodate an expandable ejector unit (50).

13. A grinding mill, characterized in that the grinding mill comprises at least one wear-resistant lining element according to any one of claims 1-12.

14. A grinding mill according to claim 13, further comprising means for operating the ejector units (50), such as hydraulic or pneumatic lines or hoses extending to each ejector unit (50) in the grinding mill.

15. A grinding mill according to any of claims 13 or 14, characterized in that the wear-resistant liner elements (30, 30 ') are supported end-to-end in the longitudinal direction of the shell and/or in a circular array on the inner surface of at least one end wall, and that a series of a plurality of the wear-resistant liner elements (30, 30') is arranged such that one, more or all wear-resistant liner elements in the series are provided with an ejector unit (50).

16. A grinding mill according to claim 13 or 14, wherein a backing such as a rubber backing is provided on an inner surface of a shell or end wall, the inner surface facing the outer surface of the wear-resistant lining element, the rubber backing being adhered to the inner surface of the shell or end wall.

17. A finishing machine as claimed in claim 13 or 14, characterized in that the finishing machine is associated with a control unit to control the activation of one or more ejector units, for example from a remote location, for example by means of a wireless connection.

18. A wear-resistant lining element for a cylindrical shell of a horizontal or vertical grinding mill,

it is characterized in that the preparation method is characterized in that,

the wear-resistant liner element (30) comprises an ejector unit engagement section configured to receive or accommodate an expandable ejector unit (50), the expandable ejector unit (50) being arranged between an outer surface of the wear-resistant liner element (30) and an opposite inner surface of the shell, the ejector unit (50) having a first portion for abutting or engaging the outer surface of the wear-resistant liner element (30) and a second portion for abutting or engaging the inner surface of the shell, and the ejector unit (50) being operable to increase the spacing between the first portion and the second portion, thereby increasing the spacing between the outer surface of the wear-resistant liner element (30) and the inner surface of the shell.

19. A wear-resistant lining element for an end wall of a horizontal grinding mill,

it is characterized in that the preparation method is characterized in that,

the wear-resistant liner element (30 ') comprises an ejector unit engaging section configured to receive or accommodate an expandable ejector unit (50), the expandable ejector unit (50) being arranged between an outer surface of the wear-resistant liner element (30') and an opposite inner surface of the end wall, the ejector unit (50) having a first portion for abutting or engaging the outer surface of the wear-resistant liner element (30 ') and a second portion for abutting or engaging the inner surface of the end wall, and the ejector unit (50) being operable to increase the spacing between its first and second portions to increase the spacing between the outer surface of the wear-resistant liner element (30') and the inner surface of the end wall.

20. A wear-resistant lining element according to claim 18 or 19, characterized in that the ejector unit engaging section is a groove (60) in the outer surface of the wear-resistant lining element (30, 30') for accommodating the expandable ejector unit (50).