RU2798529C2 - Vertical ball mill, stator segment for vertical ball mill and method for maintenance of vertical ball mill - Google Patents

Abstract

FIELD: equipment for grinding minerals.

SUBSTANCE: vertical ball mill contains a rotor fixed in the axial and radial direction at the upper end and hanging down, a stator radially surrounding the rotor, not loaded by the mass of the rotor, installed without the use of additional elements and having a side surface oriented tangentially to the rotor and having a cylindrical shape with mould tolerance, and base plate. The stator contains at least two stator segments separated from each other, installed without support separately from each other and movable relative to each other, each of them contains at least one side edge of the wall extending from the upper edge of the wall forming the side surface to the bottom edge of the wall, a sealing surface for sealing against another stator segment in each case, and on the bottom edge a bearing surface sized to suit the load and designed to seal against the base plate.

EFFECT: invention provides high efficiency during use.

17 cl, 13 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The invention relates to a vertical ball mill, in particular for pre-grinding material such as minerals, a stator segment for a vertical ball mill, and a method for maintaining a vertical ball mill.

BACKGROUND OF THE INVENTION

In a ball mill, grinding materials are used for grinding. In this case, the material to be ground is loaded into a slurry, also called "pulp" or "slurry", and moved inside the mill. Grinding materials, as a rule, have a spherical shape and are called, among other things, grinding balls or bodies. The material to be ground is understood in particular to be minerals and mineral aggregates, in particular metal ores, as well as substances of similar hardness, in particular coal ores, recoverable materials, etc. In the following description, the grinding of minerals will be described by way of example.

In conventional mills, minerals are mixed with grinding balls to grind the minerals. Some of the grinding balls and minerals rise to a height determined by the design and from that height fall back into the bed of the rest of the grinding balls and minerals. In this case, the falling grinding balls collide with the rest of the grinding balls. The minerals between them are broken.

A conventional ball mill may comprise, for example, a horizontal, i.e. rotating around a horizontal axis drum, wherein the minerals are crushed by the action of the grinding balls. In the case of a stirrer-type mill, gravity ("gravity mill") is also used as an essential element for generating the grinding forces.

In a mill that uses predominantly gravity, a hydrostatic pressure is set to promote grinding. This design means multiple lifting of the grinding materials. This requires lifting work provided by a rotatable auger. Grinding takes place in the layer of balls. Most of the load is due to gravity, and a smaller part is due to centrifugal forces. The part of the crushing forces that occurs under the action of gravity cannot be changed. Thus, the crushed material is lifted by the screw and returned down to the periphery. The primary transportation of the crushed material is provided by a screw, and a certain part is provided by the action of hydrodynamic forces in the pulp. Such a grinding or conveying mechanism may result in the discharge of coarse material. Typically, this requires an external fractionation circuit.

In the prior art, there are many variants of devices for grinding minerals, which can be simplistically classified as horizontal and vertical mills. A vertical agitator mill containing grinding aids for homogenizing, dispersing and grinding solids in liquids is disclosed in patent application DE 1 901 593 (A1). In addition, vertical mills have proven themselves in the mining industry (mines, etc.) (see, in particular, patent application WO 2007/019602 A2).

An alternative is mills in which the grinding forces are predominantly generated in the fluidized grinding bed and can be generated and controlled by the rotor speed (so-called "fluidized bed mills"). At IMCET 2013 (“23rd International Mining Congress and Exhibition in Turkey”, Kemer/Antalya/Turkey, April 16-19, 2013, in particular, at session 1, a vertically oriented mill for fine grinding of minerals was proposed: “Technology A new concept for fine grinding by I. Roito et al. Outotec HIG Mills: Fine Grinding Technology. The proposed mill for fine grinding of pre-ground minerals contains a vertically oriented stator, consisting of two half-shells and containing stationary annular grinding disks, the stator being suspended on a solid platform, and a rotor mounted on one side in the stator and containing a shaft on which rotary grinding disks are installed. In addition to the central rotor, driven by motor-reducers up to 5000 kW installed on the platform, the stator is also suspended on the specified platform. An inhomogeneous mixture containing water and grinding materials is ground between rotating and stationary grinding disks fixed on the body until the material to be ground reaches the required grain size and granulometric composition. This occurs when the net volume (filling volume) is not more than 30 m ³ . To make the grinding process fundamentally possible, the grinding method used in the process (sometimes referred to as the HIG process; ultrafine grinding technology) involves the grinding of pre-treated minerals in several stages.

DISCLOSURE OF THE INVENTION AND SOME VARIANTS OF ITS IMPLEMENTATION

Given the above and using the proposed approach, a vertical ball mill is proposed, in particular for coarse pre-grinding of minerals, a stator segment for a vertical ball mill, as well as a method for maintaining a vertical ball mill with features disclosed in independent claims. Preferred embodiments and refinement of the approach set forth herein are disclosed in the specification and dependent claims.

Embodiments of the present invention advantageously reduce the energy consumption for pre-grinding of minerals and thereby increase efficiency, as well as modify the design of the mill used for pre-grinding, so as, in particular, to facilitate its assembly, disassembly and maintenance.

In particular, the proposed approach provides a robust structure that can be designed to reduce material consumption and significantly lighten the design compared to prior art concepts. Thus, the structure, partially disassembled, can be transported relatively easily to the area in the immediate vicinity of the mine or to the site of operation. The required regular maintenance work can be significantly reduced and simplified using the approach proposed in this application. The concept of the machine reduces the risk of injury. The overhaul of the proposed mill can be relatively simple, ie, specially trained personnel may not be required. In addition, the approach outlined in this application may improve process control and facilitate correction of the quality of the mined material. The crushed material can be subjected to further processing or cleaning and/or transferred directly to the next process. In the case of major and current repairs for disassembly and assembly, as a rule, no additional lifting mechanisms are required. Spare parts can be stored at the production site, taking up little space, in the same volume as the main components to be replaced, such as the mill shaft with grinding discs or individual grinding cylinders. Horizontal shifting and positioning of spare parts can be carried out safely by several people, for example with guides and rollers. Added to this is the reliable and fast emptying of the chopping cylinder without significant loss of material.

According to a first aspect of the invention, a vertical ball mill is provided, in particular for grinding pre-ground material such as minerals. The vertical ball mill contains: (i) a rotor fixed in the axial and radial direction at the upper end and hanging down, (ii) a stator radially surrounding the rotor, not loaded by the mass of the rotor, installed without the use of additional elements and having a tangentially oriented side surface to the rotor and having an approximately cylindrical shape, with shape tolerance, and (iii) a base plate on which the stator mass rests. In this case, the stator comprises at least two stator segments, which can be separated from each other, installed without support separately from each other and move relative to each other. Each of the stator segments contains at least one side edge of the wall, a sealing surface for sealing against another stator segment in each case, and on the lower edge - a bearing surface, the dimensions of which correspond to the load, and which is intended for sealing against the base plate. In this case, said side edge of the wall extends from the top edge of the wall forming the side surface to the bottom edge of the wall. The stator segment uses the bearing surface as a bearing on the base plate at right angles to the bearing surface of the base plate with an angular tolerance.

In addition, in a second aspect of the invention, a stator segment installed without the use of additional elements is provided for a vertical ball mill according to the present application. It contains: i) a wall having the shape of a cylindrical segment with a shape tolerance; ii) at least one sealing surface located on the side edge of the wall, extending from the upper to the lower edge of the wall, and designed to seal against another segment of the stator; iii) a bearing surface located on the lower edge, sized appropriately for the load and allowing the stator segment to be mounted on the bearing surface of the ball mill base plate at right angles with angular tolerance. In this case, the stator, installed without the use of additional elements and having a side surface formed by walls and having the shape of a round cylinder with a shape tolerance, may contain several stator segments, and the stator in the assembled state may be supported in the form of a base plate that can withstand the mass of the stator.

Further, according to a third aspect of the invention, there is provided a maintenance method for a vertical ball mill, in particular for grinding pre-ground material such as minerals. The vertical ball mill may correspond to the aforementioned ball mill according to an embodiment of the first aspect of the invention and, as in the previous example, comprises a rotor axially and radially fixed at the upper end and hanging down, a stator radially surrounding the rotor, not loaded by the mass of the rotor, mounted without the use of additional elements and having a side surface oriented tangentially to the rotor and having an approximately cylindrical shape, with a shape tolerance, and a base plate on which the stator mass rests. The stator contains at least two stator segments, which can be separated from each other, installed without support separately from each other and move relative to each other. Each of the stator segments comprises at least one side edge of the wall extending from the top edge of the wall forming the side surface to the bottom edge of the wall, a sealing surface for sealing against the other stator segment in each case, and on the bottom edge, a bearing surface, dimensioned to suit the load and designed to seal against the base plate. The stator segment uses the bearing surface as a bearing on the base plate at right angles to the bearing surface of the base plate with an angular tolerance. The method comprises at least the following steps, preferably in this order:
dividing the stator into stator segments, the stator being divided along the sealing surfaces,
installing accessories under at least one of the stator segments, and
lateral displacement of the stator segment and auxiliaries by means of a shifting device.

The stator segment can be lifted off the base plate using hoists before the accessories are installed and mounted on the auxiliaries using hoists.

The ideas of embodiments of the present invention may be considered, inter alia, and without limiting the scope of protection of the invention, as based on the concepts and results described below.

A vertical ball mill can be understood as a device for grinding the material to be ground using grinding materials. The material to be ground can be, for example, pre-pulverized rock or minerals from a mine. The rock or minerals can, for example, be crushed and fractionated in a crusher, roller mill (with high pressure grinding rollers), self-attrition mill or partial self-attrition mill before being fed to the vertical ball mill.

The vertical ball mill described in this application can be used at the stage of grinding the extracted raw materials. The material to be ground is fed into the ball mill in lumps or in the form of a suspension in a fluid carrier or conveying medium. The carrier medium can be, for example, water. The material to be ground may contain a portion of the desired raw material. For example, the material to be ground may contain a portion of the ore. The main part of the crushed material may not contain the desired raw material. As a result of grinding, small particles are formed, which are processed in subsequent stages of the process. The proportion of particles containing the desired raw material can be increased, for example, in the next stage of enrichment. For example, at the stage of enrichment, you can use a different density of particles of material that does not contain raw materials, and particles that contain the desired raw materials.

The proposed vertical ball mill can have a large filling volume in excess of 20 m ³ . In practice, for economical pre-grinding of minerals, mills with a net volume (filling volume) of 20 to 150 m ³ are required. In order to obtain a large filling volume, the vertical ball mill is sized appropriately, so it exhibits large size and weight. The speed of the grinding discs can be up to 15 m/s. The power of the drive motors can reach approximately 12,500 kW.

The grinding materials may, for example, have a spherical shape. Grinding materials may contain wear resistant materials. In particular, the hardness of the grinding materials may exceed the hardness of the grinding material. The grinding materials may comprise, for example, a metallic material, in particular steel or a ceramic material.

The grinding materials, the material to be ground and the carrier medium are surrounded by a liquid-tight sheath. During operation, the shell is connected to the substrate without the possibility of movement. Thus, the shell can be called a "stator". Grinding materials are moved in the shell by means of a drive element of a ball mill. The drive element can be called a "rotor". Grinding materials can move in the stator in an approximately circular path, without appreciable displacements up and/or down. The circular path can run perpendicular to the main vertical axis of the ball mill within the angular tolerance. Angular tolerance can be called "position tolerance". The angular tolerance may be, for example, 10° or less, preferably 5° or less, particularly preferably 2° or less.

The material to be ground is abraded or ground between the grinding materials when the grinding materials are pushed against each other and/or rolled against each other at different speeds. The different speeds of the grinding materials are obtained due to the fact that the grinding materials in the immediate vicinity of the rotor move approximately at the speed of the surface of the rotor. In contrast, the grinding materials in the immediate vicinity of the stator are essentially not moved. Thus, between the rotor and the stator there is a profile of the speed of movement of the grinding materials. Faster grinding materials closer to the rotor collide with or rub against slower grinding materials closer to the stator.

The rotor can be aligned on the main axis with an angular tolerance. The rotor can be made with the possibility of rotation around the main axis. The rotor can be mounted in a cantilevered way. In this case, the rotor may not be supported at the lower end. However, additional bearing support of the lower end should not be ruled out. Due to its own weight, the rotor can be held in a suspended position, that is, in such a way that it is essentially perpendicular to the substrate.

The stator can be opened from above. The rotor may be immersed in a carrier medium containing the material to be ground and the grinding materials substantially vertically from above. The rotor can be installed independently of the stator. The stator may be spatially, statically and/or mechanically separated from the rotor or rotor bearing.

The stator has an approximately cylindrical side surface with shape tolerance. In other words, the stator may surround a volume in the form of a cylinder, in particular a round cylinder. To this end, the stator may preferably have an approximately circular cross-section within the shape tolerance, i.e. it may have a rotationally symmetrical shape. The stator may also have an oval, triangular, octagonal, polyhedral or substantially polygonal cross section. The cross-sectional area can be kept constant, within shape tolerance, from the bottom edge of the stator to the top edge of the stator. The shape tolerance describes the allowable deviation from the cylindrical shape. The shape tolerance may be, for example, 10% or less, preferably 5% or less, particularly preferably 2% or less, based on the overall dimensions of the stator. In other words, the stator may be out of round within the shape tolerance.

The lateral surface describes the interface between the grinding materials, the carrier medium and the material to be ground. The side surface may be formed by the inner surface of the stator. The side surface may be perpendicular or plumb vertical within the angular tolerance.

The base plate transfers the mass of the stator, the grinding materials, the carrier medium and the material to be ground completely, or at least in the predominant part, to the base and is designed for the corresponding load. The base plate can be rigidly connected to the base. The base plate may contain a bearing surface as a mating area with the stator. The bearing surface may be shaped to match the stator cross-sectional shape within the shape tolerance. The base plate may be flat on one face or two opposite faces. The base plate may contain a reinforcing insert in the region of the bearing surface. The base plate may comprise a metallic material. The base plate may, for example, be a separate component and be supported on the base. The base plate can also be mounted on supports and arranged in such a way that it can be installed at some distance from the base. Alternatively, the base plate may be in the form of a specially designed section of the base.

The stator segment may have a substantially arcuate base shape. The wall of the stator segment forms a subregion of the lateral surface. The wall can reproduce a range of side surface angles. If the stator consists of two stator segments, each of the two walls can reproduce a range of 180° angles. In the case of three stator segments, each wall can reproduce an angle range of 120°. In the case of n>3 stator segments, each wall can reproduce a range of (360/n)° angles. The stator segments can be divided in various ways in the circumferential direction.

The wall thickness is suitably designed for the load. In particular, the wall of the stator segment can be structurally designed, i.e., in particular, have a thickness and/or stiffeners to withstand the forces and loads that occur in the case of the described mill, in particular when the stator segments are installed on the base.

A protective layer can be applied to the inner surface of the wall to prevent direct contact between the grinding materials and the wall. Stiffening ribs can be provided on the outer side of the wall.

The side edges of the wall may be oriented perpendicular to the top and/or bottom edge within the angular tolerance. The sealing surface may be oriented perpendicular to the tension direction of the connecting elements for connecting the stator segments. With a tangential tension direction, the sealing surface can be oriented radially. With a radial tension direction, the sealing surface can be oriented tangentially. The support surface may be oriented perpendicular to the intended load direction. The support surface can be oriented horizontally within the angular tolerance. The sealing surface and/or the bearing surface may be formed by stiffening ribs located on the edges of the wall.

The stator segments are movable and/or liftable from the base plate. Prior to this, the mechanical connection to the base plate may be exposed. Thanks to the mobility of the stator segments, the vertical ball mill can be easily opened. Access to the rotor in an open ball mill is easy and maintenance work can be easily done on the inner surfaces of the stator segments.

On the inner surface of the walls of the stator segments, several horizontal ribs can be provided, located at some distance from each other vertically and having the shape of a ring segment. On the assembled stator, the ribs may form inwardly projecting annular surfaces, referred to in this application as braking surfaces. The rotor may comprise a plurality of horizontal disks spaced vertically apart, each having an outer annular surface, referred to in this application as a "loading surface". The ribs and discs may be arranged alternately in the vertical direction. The inner diameter of the braking surfaces may be smaller than the outer diameter of the loading surfaces. In this way, the braking and loading surfaces can overlap, at least partially, in the horizontal direction. A meandering labyrinth can be formed between the ribs and discs. The labyrinth increases the resistance to pulp movement through the ball mill. Therefore, the ribs are considered as deflection surfaces. The ribs can be oriented perpendicular to the wall within the angular tolerance. The disks can be oriented perpendicular to the rotor shaft within the angular tolerance. The discs may be round within shape tolerance. The disks may also be polygonal. The ribs or braking surfaces as well as the walls can be provided with a protective layer, for example preventing direct contact with the grinding balls. The discs may also contain a protective layer. The protective layer may be replaceable. The ribs forming a common braking surface on the assembled stator may be located at the same height on the stator segment and have the same width or height. The fins and disks can be spaced at equal distances from each other. The discs may contain holes between the loading surfaces and the rotor shaft. The loading surfaces of the rotor, as a rule, increase the contact area of the carrier medium, the crushed material and grinding materials with the rotor. Feeding surfaces can improve the acceleration of the carrier medium, grinding material and grinding media. The speed of movement of a point on the disks increases in proportion to the distance from the axis of rotation of the rotor. The loading surfaces move at the highest speed on the outer diameter of the rotor. The braking surfaces of the stator increase the contact area of the carrier medium, crushed material and grinding materials with the stator. Braking and loading surfaces can improve respectively the deceleration or acceleration of the carrier medium, grinding material and grinding materials. During operation, a large speed difference occurs between the loading and braking surfaces. As a result, a large velocity gradient develops in the carrier medium, the grinding material and the grinding materials, which leads to a large difference in speeds between the individual grinding materials. A high speed difference leads to an increase in impact or friction forces, and the material to be ground is effectively ground. The main grinding area of the vertical ball mill can be located between the loading and braking surfaces.

On the outer side of each stator segment, thrust elements can be provided for lifting and moving the corresponding stator segment. The thrust members may be fixed points specifically designed to make contact with the lifting device. The thrust elements can be dimensioned according to the load. The thrust elements can be connected to the wall and/or stiffeners using a reinforcing structure. For example, thrust elements can be connected with additional ribs. For safety reasons, the dimensions of the thrust elements can be taken with a margin. Thrust elements can be designed specifically for a given type of lifting mechanism. For example, stop rods can be used for belts, cables, chains, and eyelets. Thrust eyes may be provided for hooks. Thrust surfaces can be used to absorb the pressure forces of lifting devices.

Each of the stator segments in the area of the lower edge of the wall may contain thrust elements designed, in particular, for mounting hydraulic jacks. To this end, the stop elements may comprise, for example, stop surfaces oriented substantially horizontally. In addition, the thrust elements may have a special mating geometry. For example, spherical or spherical dome shaped surfaces on the anvil or elevator may interact with spheres or spherical domes on the elevator or anvil to form an angle-insensitive support.

The thrust elements can define the corner points of a virtual horizontal polygon, in particular a triangle whose geometric center is located on a vertical axis passing through the center of gravity of the standing stator segment. In the case of a triangle, the geometric center is located at the intersection of the bisectors of the angles of the triangle. In the case of a square, the geometric center is located at the intersection of the diagonals of the square. The distribution of mass between the thrust elements can be set by the position of the thrust elements. Matching the axis through the center of gravity and the center point of the polygon can maximize the tipping resistance when lifting the stator segment.

The ball mill may include a shear device for lateral displacement of the stator segments separated from each other, and the shear device contains movable auxiliary devices designed to be installed between thrust elements and guides located on the ground and oriented parallel when the stator segment is raised, and to move along the guides together with a stator segment laid on them. The guides can be rigidly connected to the base. Auxiliary devices may contain plain bearings or rolling elements to reduce friction during movement. The rolling elements can be, for example, rollers mounted for rotation. The rollers themselves can be supported by rolling or sliding bearings. In the case of a sleeve bearing, the mass of the stator segment is distributed over a large area, whereby a low contact pressure can be achieved. Plain bearings are lubricated using a lubrication system. Alternatively or in addition, the material pairs between the plain bearings and the guide may have a low coefficient of friction. For example, a plain bearing may comprise a sliding surface of PTFE, POM, or a similar material. The stator segment can be moved along with the auxiliaries using a mover. The movement device may be mounted between the stator segment and the fixed point and develops tensile and/or compressive forces in the direction of movement determined by the guides. The moving device may, for example, comprise at least one coiled cable, a chain hoist or a hydraulic cylinder.

The shearing device may comprise at least one inclined support for use of a thrust element mounted at some distance from the vertical from the bearing surface on at least one of the guides to prevent the stator segment from tilting during lifting and shifting. The tilt support can hold the stator segment at an appropriate distance from the ground. To do this, the inclined support can connect the guide with a higher thrust element at an angle of inclination. The tilt support can be movable, i.e. move independently of the stator segment, and can be attached to the stator segment only when the stator segment needs to be moved.

Alternatively, the ramp may be rigidly connected to the stator segment and remain in place during operation. The tilt support can be connected to the bottom thrust element by means of a bottom connection. The bottom connection can prevent the tilt support from slipping sideways. The tilt support can also be used to orient vertical flanges. One of the thrust elements for lifting the stator segment can be mounted on an inclined support. Further, on the lower edge of the wall, two further lifting elements can be arranged, positioning them generally on a connecting line passing through the center of gravity of the standing stator segment.

The stator segment may contain at least one working platform. The work platform can be oriented horizontally on a standing stator segment within the position tolerance. The working platform may extend along the outer contour of the stator segment. The lower working platform can be located on top of the stator segment. The minimum vertical distance between higher work platforms may be appropriate for the height of a standing person. A ladder can be mounted on the tilt support to allow access to the work platform. The work platform and ladder may include railings and/or fall protection devices. The stator segment for maintenance work can be easily accessed from the work platform. The working platform makes it possible not to use mobile scaffolding during maintenance work.

The guides may be recessed into the base of the ball mill and may be additionally covered with guards when not in use. For example, guides can be cemented. The guides can be laid into recesses in the base. Protective devices protect the guides from dirt and damage. In particular, this makes it possible to protect the surface of the guides from damage. The upwardly oriented surface of the protective device covering one or more rails may be flush with the surface of the base. The guards may be designed so that they can be walked on. Thus, the space around the vertical ball mill remains accessible.

The ball mill may include an unloader for emptying the ball mill. Since the grinding materials are left in the ball mill during operation, before opening the stator, the grinding materials can be unloaded by means of an unloading device together with the rest of the carrier medium and the material to be ground. The unloading device can be made, for example, in the form of a damper or a valve in the wall of the stator segment.

The unloading device may include an inclined base within the bearing surface of the base plate. One of the stator segments may include an unloading hole for the unloading device in the area of the lower point of the inclined base. The inclined base allows the grinding materials to flow sideways under gravity during discharge. The inclined base has a slope from the lowest point to the highest point. The slope may, for example, be within an angular tolerance of 1-5°, preferably 2-3°, particularly preferably 2.5°. The inclined base can be made in the form of an inclined plane. The inclined base can also be made in the form of a three-dimensional surface oriented towards the bottom point. The discharge hole is a through hole in the wall. The discharge opening can be made in the form of a pipe connection. The pipe connection can be made, for example, in a standard manner. The pipe connection can be made, for example, in the size DN 150. The relief opening can contain a suitable fitting, such as a gate valve, damper, cock or valve.

One of the stator segments may contain at least one flushing hole of the unloader in the region of the upper point of the inclined base. A flushing fluid, in particular a flushing liquid, can enter the interior of the stator through the flushing opening. The flushing hole can be made in the form of a pipe connection. The flushing hole can be made, for example, in a standard way. The flushing port can be made, for example, in the size DN 100. The flushing port can contain a suitable fitting, such as a gate valve, damper, cock or valve. The flushing port may be located opposite the discharge port. The emptying of the ball mill is supported by washing. For example, a fluid may be introduced through a flush port, causing the fluid to generate a flush stream over the ramp.

The ball mill may include a frame separated from the stator. The frame supports may be supported on the base of the ball mill in such a way that they are located at some distance to the side of the stator. At least one cross beam of the frame may connect the supports above the stator. The bearing arrangement of the rotor may be supported on a cross beam. In other words, the ball mill may be provided with a frame designed so that it is separate from the stator and does not transfer the load to the stator, and the bearing and drive support is held and supported on the cross beam of this frame in such a way that these components do not transfer load on the stator. The frame may consist, for example, of steel beams screwed together. The frame can be made in the form of a portal, under which the stator is located. Thanks to the frame, the stator can be dismantled without the need to replace the rotor. The stator segments can be moved laterally away from the rotor, for example for maintenance work.

The ball mill may include a disconnect device for lateral disconnection of the rotor, which can be disconnected from the top sleeve. The disconnecting device may include at least one guide and one connecting device. The connecting device can be designed in such a way that it is connected to the rotor in the area of the connecting device, lowered onto the guide along with the rotor and moved along the guide along with the rotor. The decoupler can move the rotor to a serviceable position while leaving the drive in place. The rotor can be separated from the drive in the area of the clutch. The coupling can be screwed, for example, with several screws. A thrust element can be connected to the coupling, which allows lifting the disconnected rotor with a crane. The geometry of the coupling device may correspond to the contour of the rotor in the area of the clutch. The coupling device may surround the rotor shaft. The connecting device may contain thrust elements for attaching the lifting mechanism. In particular, the thrust members can be designed to support hydraulic jacks. The guides may also contain thrust elements for attaching hydraulic jacks. The decoupling device may include, in particular, two guides located on both sides of the rotor shaft.

The frame may contain a maintenance cabin in the area of the rotor clutch. The clutch can be accessed from the maintenance cab. The maintenance cabin can be used to securely store tools. The maintenance booth can protect the clutch from the environment.

It should be noted that some of the possible features and advantages of the invention are described herein with reference to various embodiments of a ball mill, a stator segment, or a ball mill maintenance method. The person skilled in the art will appreciate that the features of the ball mill, stator segment and method can be combined, transferred, adapted and/or replaced as appropriate to obtain other embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below with reference to the accompanying drawings, and neither the drawings nor the description can be interpreted as limiting the scope of protection of the invention.

In FIG. 1 is a three-dimensional view of a vertical ball mill according to one embodiment;

In FIG. 2 is a three-dimensional view of an open vertical ball mill according to one embodiment;

In FIG. 3 is a three-dimensional view of a stator segment of a vertical ball mill according to one embodiment;

In FIG. 4 is a sectional view of a vertical ball mill according to one embodiment;

In FIG. 5 is a sectional view of a vertical ball mill according to one embodiment;

In FIG. 6 is a flow chart of a maintenance method for a vertical ball mill according to one embodiment;

In FIG. 7 is a three-dimensional view of a closed vertical ball mill according to one embodiment;

In FIG. 8 is a three-dimensional view of an open vertical ball mill according to one embodiment;

In FIG. 9 is a three-dimensional view of a stator segment of a vertical ball mill according to one embodiment;

In FIG. 10 is a three-dimensional view of the working platform of a vertical ball mill according to one embodiment;

In FIG. 11 is a three-dimensional view of a vertical ball mill shear device according to one embodiment;

In FIG. 12 is a detailed view of the support flange of a vertical ball mill according to one embodiment; And

In FIG. 13 is a detailed view of the sealing flange of a vertical ball mill according to one embodiment.

The figures are shown schematically and not to scale. Like reference numerals in the figures refer to identical or functionally identical elements.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

In FIG. 1 is a three-dimensional view of a vertical ball mill 100 in accordance with one embodiment. In a ball mill 100 having a very large filling volume of 12 m ³ to about 150 m ³ , a slurry of coarsely ground material can be continuously ground in a carrier fluid by moving the grinding materials, with grinding being performed from an average initial grain size of about 10-100 times to the average specified grain size. Grinding materials can be, in particular, metal and/or ceramic balls, the diameter of which is about 2-50 times the diameter of the original grain size. In this case, the initial grain size can be up to 15 millimeters. In this case, the grinding materials may have a size of 5 to 50 millimeters. As a result, the ball mill 100 can be used as a grinding stage in a multi-stage development process such as raw material mining. In this case, the crushed material may contain the desired minerals and waste rock, which must be separated.

Ball mill 100 includes a suspended rotor for moving grinding materials. A free-standing stator 102 radially surrounds the ball mill chamber 100 and the rotor, acting as a sheath for the slurry and grinding materials. The volume of the working chamber shown here inside the stator 102 of the ball mill 100 is between 12 and 150 cubic meters. During operation, the working chamber is predominantly filled with a layer of grinding materials containing a plurality of grinding materials. In this case, the slurry containing coarsely ground material is continuously introduced into the layer of grinding materials in the lower part of the working chamber at a flow rate of 50 to 5000 cubic meters per hour. The material to be ground is ground as it passes through the layer of grinding materials. At the top of the working chamber, the slurry containing the crushed material flows out of the layer of grinding materials and is removed from the working chamber, while the grinding materials remain in the working chamber.

When the rotor rotates during the grinding process, a shear flow is formed between the stator 102 and the rotor, since the boundary layer between the rotor and the slurry surrounding the rotor and containing grinding materials is moved essentially with the angular frequency of rotation of the rotor, and the boundary layer between the stator and the slurry, containing grinding materials is essentially stationary at the stator 102. A shear flow velocity profile is formed between the rotor boundary layer and the stator boundary layer, as the slurry and grinding materials move faster the closer they are to the rotor. The speed profile causes a lot of collisions between fast and slow grinding materials, resulting in grinding of the grinding material located between them. The material to be ground is washed upward by the flow of the carrier medium in the working chamber, which is formed during the passage of the suspension through the layer of grinding materials.

The stator 102 includes a side surface 104 having a substantially approximately cylindrical shape and enclosing the rotor as shown in FIG. At its upper end, the rotor is mounted axially and radially above the stator 102 and hangs down into the working chamber. The bearing and driving device 106 of the rotor rests directly on the base 110 of the ball mill 100 by means of a free-standing frame 108. In this case, the bearing and driving device 106 includes four electric motors 107 with a total power of 0.8 to 12.5 megawatts, which drive the rotor through general transmission. It is also possible to use a smaller number of at least one electric motor. There is no bearing contact between frame 108 and stator 102. The torque of the bearing and drive device 106 through the frame 108 is diverted to the base 110. The stator 102 is installed without the use of additional elements on the base plate of the ball mill 100. The base plate perceives the mass of the stator 102, the reactive torque of the drive, as well as the mass of grinding materials, minerals and carrier medium onto base 110. In FIG. 1 base plate is closed by stator 102.

The stator 102 can be divided, in particular for maintenance purposes. In this case, the stator 102 consists of two almost identical stator segments 112. Stator 102 may also include more than two stator segments 112. The stator segments 112 are interconnected by sealing flanges 114. The sealing flanges 114 extend from the upper edge of the stator 102 to the lower edge of the stator along the side edges of the wall 116 of the stator segments 112. To connect the stator segments 112, for example, sealing flanges 114 can be screwed on. To separate the stator segments 112, the screws can be loosened again. Alternatively, adjacent stator segments 112 may be otherwise releasably mechanically coupled to each other. The sealing flanges 114 form the sealing surfaces 118 to hermetically seal the working chamber. Additional seals may be located between the sealing surfaces 118. Sealing surfaces 118 or seals prevent leakage of the slurry in the connecting seams of the stator 102. The sealing flanges 114 may further include drainage channels. The drainage channels can purposefully divert possible leakage of the carrier medium into the collection system. The wall 116 of the segment 112 of the stator reproduces the segment of the side surface 104 of the stator 102, having the approximate shape of a cylindrical segment and reinforced on the outside with several tangential ribs 117 of stiffness. In addition, the wall 116 from the outside is reinforced with several ribs 119 oriented in the axial direction. The sealing flanges 114 substantially correspond to the axial stiffeners 119 along the side edges. The stiffening ribs 117, 119 reinforce the stator 112, in particular to resist the hydrostatic pressure of the carrier medium.

A peripheral support flange 120 is provided on the lower edge of each stator segment 112. The support flange 120 is a tangential rib extending along the lower edge of the walls 116. forces due to the mass of the stator segments 112 and possibly also the mass of the grinding materials and the material to be ground can be dissipated. For example, the support flanges 120 may be screwed to the base plate. The support flanges 120 form a support surface 122 of the stator 102 that is sized to match the load. The stator 102 rests with its entire mass on the base plate by means of the base surface 122. The base surface 122 simultaneously serves as the sealing surface 118 and seals the connection with the base plate. The seal may also be located between the bearing surface 122 and the base plate. Drainage channels may also be located between the support surface 122 and the base plate.

To access the rotor, the working chamber can be emptied, i.e. the grinding material and grinding materials can be removed. The stator segments 112 can then be moved laterally. Before moving open the mechanical connection between the segments 112 of the stator and between the segments 112 of the stator and the base plate. The stator segments 112 can then be individually lifted by means of a lifting device to move them laterally apart from the base plate. For example, hydraulic jacks can be used as a lifting device. For lifting, each stator segment 112 includes a plurality of thrust members 124. The thrust members 124 are located in the region of the lower edge of the wall 116. In this case, the thrust members 124 are in the form of brackets protruding beyond the bearing surface 122 and comprise downward thrust surfaces.

In one embodiment, ball mill 100 includes a shear 126. Shear 126 includes three travel paths 128 per stator segment 112 along which stator segment 112 can be moved away from another stator segment 112. In this case, the movement paths 128 are formed by guides 130 anchored into base 110. Guides 130 and base 110 can bear the mass of stator segment 112 with a margin. For displacement, the lifting segment 112 of the stator is lowered by means of a lifting device onto the auxiliary devices. The auxiliaries are positioned between the thrust members 124 and the guides 130 and receive the mass of the stator segment 112 lowered thereon by the guides 130. The auxiliaries provide clearance between the bearing surface 122 and the base plate even in the re-lowered state. The stator segment 112 is moved along the movement path 128 by means of auxiliary devices.

In one embodiment, the auxiliary devices are in the form of skids that slide over the surface of the rails 130 with a sliding lining and additional lubrication. Traction and/or propulsion systems may be used to move the stator segment 112 along the rails 130.

In an alternative embodiment, to move the stator segment 112, strong rollers are provided, located between the thrust elements 124 and the base 110, having the dimensions corresponding to the load, and transferring the mass of the stator segment 112 directly to the base 110. The stator segment 112 can be freely moved on strong rollers.

In one embodiment, at least one of the stator segments 112 has at least one ramp 132. Prior to movement, the ramp 132 may be rigidly attached to the stator segment 112, or alternatively may be secured to the thrust elements 124 segments 112 of the stator provided for this. The tilt support 132 can be supported on the base 110 by means of a strong roller. Alternatively, the ramp 132 may be part of a shear device 126. The ramp 132 is then connected to one of the rails 130 by an additional accessory 134. The accessory 134 may be in the form of a skid. An additional accessory 134 may be secured to prevent lift from the rail 130. To do this, the accessory 134 may at least partially surround the rail 130. The accessory 134 may transmit compressive and tensile forces to the rail 130. In addition, the length of the ramp 132 can be adjusted to compensate for the rise and fall of the stator segment 112 or to correct the angular position of the stator segment 112 relative to another stator segment 112.

In the illustrated embodiment, the guides 130 are housed in the grooves of the base 110. This allows the guides 130 to be closed during operation of the ball mill 100, whereby they are better protected from damage and contamination than when open.

In FIG. 2 is a three-dimensional view of an open vertical ball mill 100 in accordance with one embodiment. In this case, the ball mill 100 essentially corresponds to the ball mill shown in FIG. 1. In contrast to FIG. 1, in this case the stator segments 112 are separated from each other. The stator segments 112 are raised on the thrust members 124, and thereby lifted off the base plate 200. Between the thrust members 124 and the guides 130 are auxiliary devices 134 on which the stator segment 112 auxiliary devices are placed. As a result, the support surfaces 122 are located at some distance from the bearing surface 201 of the base plate 200. Using the traction device 202, the stator segments 112 were laterally displaced from the base plate 200 on the auxiliary devices 134 along the trajectory 128 of the movement given by the guides 130, thus, so that service or maintenance can be carried out on the rotor 204 and/or the inner surface 206 of the stator 102. In the example shown, the stator segments 112 have been moved in opposite directions.

On the inner surfaces 206 of the walls 116 of the segments 112 of the stator, several horizontal ribs 208 can be provided, located at some distance from each other vertically and having the shape of a segment of the ring. The ribs 208 of both stator segments 112 may be equally spaced. During operation of the vertical ball mill 100, the flat sides of each rib 208 serve as annular slurry braking surfaces 210. In addition, the ribs 208 serve as deflection surfaces for the slurry flowing upwards through the ball mill 100 towards the rotor 204. The ribs 208 are equally spaced from each other. The ribs 208 on the inner surface 206 may (but need not) have a height and/or vertical distance from each other greater than those of the tangential ribs 117 on the outer side. It is also possible to design the mill cylinder without internal ribs.

The rotor 204 is shown separately from the bearing and drive device 106 and detached laterally. The rotor 204 includes several discs 212 mounted on the rotor shaft 205, spaced vertically apart and oriented perpendicular to the rotor shaft 205. On the flat sides of each disc 212, two annular loading surfaces 214 are provided to guide the slurry. The disks 212 contain holes 213 directed towards the shaft 205 of the rotor. The spokes 215 pass through holes 213 between the loading surfaces 214 and the rotor shaft 205.

When the ball mill 100 is ready for operation, the ribs 208 and discs 212 may be located in the working chamber so that they are located at some distance from each other and alternately above each other, while the braking surfaces 210 and the loading surfaces 214 can, at least at least partially overlap in the horizontal direction. By overlapping ribs 208 and discs 212 in a ready-to-operate state, a labyrinth is formed between stator 102 and rotor 204, extending the path of the slurry through ball mill 100. A configuration without internal ribs 208 is also possible. At the upper end of rotor 204, a clutch 216 is provided, through which the rotor 204 may be releasably coupled to the bearing and drive device 106.

The frame 108 includes a disconnect device 218 for disconnecting the rotor 204. The disconnect device 218 includes guides 130 connected to the frame 108 and protruding laterally beyond the transverse beams of the frame 108, and a connecting device 220. The guides 130 are located on opposite sides of the rotor shaft 205.

For the purpose of disconnection, the connector 220 is connected in the area of the clutch 216 to the rotor 204, which is connected to the bearing and drive device 106. The connector 220 is essentially U-shaped and can be pushed laterally onto the rotor shaft 205. Subsequently, the open end of the coupling device 220 is closed with a latch 222. The diameter of the coupling 216 is greater than the diameter of the shaft 205 of the rotor. Coupling device 220 is lifted to rest on clutch 216 and bearing and driver device 106 is unloaded, while the mass of rotor 204 is taken up by connector device 220. After that, clutch 116 is disconnected from bearing and driver device 106. Coupling device 220, together with the disconnected rotor 204, is lowered to supported on the rails 130. The rotor 204, together with the connector 220, is moved along the rails 130 until the connector 216 is adjacent to the crossbeam and accessible from above. Subsequently, the sleeve 216 can be lifted out of the connector 220 by means of an adapter using a crane. The connecting device 220 may include, for example, a sliding lining.

Features of the embodiment depicted in FIG. 1 and 2 are disclosed below, including with sometimes modified wording.

In FIG. 1 and 2, a ball mill 100 is shown, with the mill drive serving as the bearing and driving apparatus 106 and comprising the motor(s) 107 and transmission, located together with the mill shaft serving as the rotor shaft 205, at the top of the vertical mill on the mill platform or frame, which may serve as a frame 108. Grinding discs 212 are mounted on the mill shaft, and the shaft together with these discs may be referred to as a rotor 204. The platform at the top of the mill takes only the mass of the rotor, motor and transmission, resulting in relatively small forces. These forces are especially small compared to the forces acting when the entire mill is suspended from the top.

The grinding cylinder of the ball mill 100, which serves as the stator 102 and contains a wear-resistant lining and fixed disks in the form of ribs 208, is not structurally connected to the mill drive. The grinding cylinder can be divided into two halves of the grinding cylinder containing fixed discs. The sealing on the vertical flange and the radial flange is realized by means of an open seam. The mass of the grinding cylinder, fixed disks, grinding materials and suspension, called in this case "pulp" and consisting of the material to be ground and the carrier medium, is transferred through the anchorage to the base and diverted to the base. The design of the grinding cylinder is essentially stable enough to absorb forces. The base plate 200 is anchored in the concrete of the base to absorb and dissipate the forces of the grinding cylinder. An additional wear pad protects the base plate 200, is supported only by its own weight, and can be mechanically secured and easily removed. The pulp inlet is at the bottom side and the pulp outlet is at the top side.

During operation of the ball mill 100, the interior of the grinding cylinder or mill cylinder is filled up to 80% of the height of the grinding cylinder with grinding media (not shown in the figure). The pulp is in the gaps between the grinding bodies and above the layer of grinding bodies. In this case, the ball mill 100 is emptied through the holes into the base of the mill.

The vertical ball mill 100 shown here can be used in particular for primary, ie coarse, grinding. In this case, the material to be ground, having a maximum grain size F100 of 10 to 15 mm or F80 of 250 µm to 5 mm, is ground in an economical manner to a P80 fineness of 100 µm.

For fine-range grinding, the ball mill variant 100 can be used. In this case, fine-range refers to grinding to a P80 product fineness of 40 to 300 µm. In the fine range, the feed fineness is preferably less than 500 µm.

In the case of the proposed vertical ball mill 100, the grinding materials are oriented in a substantially vertical direction. Lifting works are practically non-existent. Grinding takes place in the areas between the rotor disks 212 and the housing disks formed by the ribs 208. The grinding chamber, and hence the feed of the material to be ground with grinding materials, is very well defined. This improves the grinding efficiency. The forces required for grinding are largely due to centrifugal forces. Under the action of gravity, there is a contact or compressive force between the grinding materials, increasing from top to bottom, and hydrostatic pressure in the stator 102, increasing from top to bottom. The speed and mass of grinding materials can influence and change the abrasive forces. The transport of the material to be ground in the vertical ball mill 100 is carried out by the gripping forces in the pulp generated by the feed pump. The holding time, and therefore the energy consumed, can be affected by the controlled delivery of the feed pump. The finished material is transported through the holes in the rotor and taken up from the mill to the bypass. A separate external monitoring loop is generally not required. However, if necessary, such a circuit can be provided.

The fine grained material presented here from the vertical ball mill 100 has a close to uniform particle size distribution, which is convenient for the next stage of processing (flotation, leaching). This corresponds to the steep progression of the grinding curve depicted in the RRRS diagram. Close to uniform particle size distribution is obtained by minimizing overgrinding. To do this, in the proposed approach, the finished product is removed from the grinding process as quickly as possible. The better this is done, the steeper the particle size distribution curve will be. Therefore, the grinding chamber of the vertical ball mill 100 is configured to meet the above conditions. This is achieved, essentially, holes in the form of holes 213 in the disks 212 of the rotor. The pump transports the pulp from the bottom up, drives it through the holes and the grinding chamber and transports fine fractions of the crushed material there. The speed is determined by the performance of the pump. The capacity is adjusted to ensure that the product is removed to the required fineness and that the coarser material remains in the grinding chamber of the mill. The crushed material, which has already reached the required fineness, is removed from the grinding chamber as quickly as possible. Thus, regrinding does not occur.

In order to be able to start maintenance work on the ball mill 100, the interior of the grinding cylinder is emptied. In this case, the grinding media and the slurry are discharged through holes and pipes into the mill base, in particular by opening the respective valves. Grinding bodies and pulp exit the grinding chamber through the holes into the base under the action of its own weight. The emptying volume can be adjusted by valves and maintained by rotating the rotor. Pipelines direct the grinding media and slurry to a suitable conveyor system installed under the mill base. As a conveyor system, for example, a belt conveyor, a screw conveyor, a pump or a bucket conveyor can be used. The list is not exhaustive.

The conveyor system transports the grinding media and slurry sideways from the ball mill 100 to a height sufficient to be loaded into a container or truck. This procedure is continued until the ball mill 100 is completely empty.

To open the stator 102 by sliding one of the stator segments 112 in the form of the first half of the grinding cylinder, the sliding guides 130 are closed and cleaned. In this case, in particular, the surface of the sliding guides is cleaned. After that, mounting supports or ramps 132 are installed on both halves of the mill cylinder, and the flanged threaded connections of the pulp supply and discharge pipes are opened. After that, the vertical and radial flange threaded connections are separated, and three hydraulic cylinders are installed in each half of the grinding cylinder. Using three hydraulic cylinders, half of the chopping cylinder is raised by about 25 mm, three Teflon skids are attached to the half of the chopping cylinder, and another skid is attached to the mounting support. Half of the chopping cylinder is lowered by three hydraulic cylinders until the Teflon sled rests on the slide rails. Then the traction and driving cylinders on both sides are connected to the provided stops of the grinding cylinder or sled. The mounting support is extended by the hydraulic cylinder until half of the chopping cylinder is raised. The half of the chopping cylinder is brought into the intended maintenance position by means of two traction and driving cylinders.

To dismantle the mill shaft as a release device 218, a carriage or shaft mounting cart is moved in the direction of the installed shaft. The carriage for mounting the shaft is lifted about 25 mm upwards by means of four hydraulic cylinders, and the shaft clamp is closed and clamped around the shaft element. After that, the tightening screws are unscrewed. The shaft mounting carriage, together with the clamped and disengaged shaft, is lowered by means of four hydraulic cylinders until the shaft mounting carriage is placed on the sliding guide. By means of at least one hydraulic shifting cylinder, the carriage for mounting the shaft, together with the shaft, is moved to a lateral or raised position, in which the shaft can be shifted using the built-in crane. Here, a means of fixing the shaft or an eye is installed on the shaft coupling. The shaft can now be lifted onto the built-in crane hook. The shaft can be installed in a suspended holding device or placed on a special repair trailer.

In FIG. 3 is a three-dimensional view of a stator segment 112 of a vertical ball mill in accordance with one embodiment. Stator segment 112 substantially corresponds to one of stator segments 112 in FIG. 1 and 2. In contrast to that shown in FIG. 1 and 2, in the illustrated embodiment, the stator consists of three stator segments 112. Wall 116 reproduces a 120° arc. The sealing flange 114 and the sealing surface 118, as well as the bearing flange 120 and the bearing surface 122, contain through holes 121, allowing each of these elements to be screwed to an appropriately designed counterpart, that is, to another sealing surface of another stator segment 112 or to the bearing surface of the bearing. plates. The depicted stator segment 112 has a mass of approximately 30 tons. Nine segments of ribs, equally spaced apart, are located on the inner surface 116.

Thrust elements 124, made in the form of brackets, protrude in the radial direction beyond the bearing surface 122 and in each case are connected to the wall 116 by two axial stiffeners. Two thrust elements 124 are located in the region of the lower corners of the wall 116.

In FIG. 4 is a sectional view of a vertical ball mill 100 according to one embodiment. Ball mill 100 essentially corresponds to the ball mill shown in FIG. 1 and 2. The ball mill 100 includes an unloader 400 for emptying the working chamber. The base plate 200 of the ball mill 100 includes an inclined base 402 as part of the unloader 400. On the inclined base 402, a surface surrounded by a bearing surface 201 that receives the mass of the stator segments 112 rises above the surface 201 and is oriented obliquely relative to the horizontal, at an angle of about 2.5 up to 30°.

One of the stator segments 112 includes a relief hole 404 in the region of the lowest point of the ramp 402, that is, where the surface of the ramp 402 is closest to the bearing surface 201. In this case, the relief hole 404 is in the form of a radially oriented pipe connecting flange. During operation, the discharge opening 404 may be closed with suitable fittings. For emptying, the valve is opened. In this case, in addition to the ball mill 100, the base 110 includes a cavity 406 in the area in front of the discharge opening 404, and containers for removing grinding materials can be placed in the cavity in order to empty the working chamber. Grinding materials, along with adhering slurry residue, can be discharged by gravity into a shipping container located in cavity 406 through discharge opening 404. During discharge, rotor 204 may be driven to eject grinding materials deposited on discs 212 to the outside.

In one embodiment, the other stator segment 112 includes at least one flush hole 408 at the top of ramp 402, i.e., where the ramp surface 402 is furthest from bearing surface 201. In this case, flush hole 408 also made in the form of a radially oriented pipe connecting flange. The flush port 408 is diametrically opposed to the discharge port. Flush port 408 can assist in emptying the process chamber by directing fluid flow into discharge port 404. During operation, flush port 408 is also closed with suitable fittings.

In addition to the upper radial and axial mounting in the bearing and drive device 106, the rotor 204 can also be mounted on the base plate 200 by means of a floating bearing. To do this, at the lower end of the rotor shaft, a bearing pin is provided, installed in a floating bearing. Changes in the length of the rotor 204 can be compensated for by offsetting the floating bearing on the bearing journal.

In FIG. 5 is a sectional view of a vertical ball mill 100 in accordance with one embodiment. Ball mill 100 essentially corresponds to the ball mill shown in FIG. 4. The difference is that in this case, the base plate 200 at least partially covers the cavity 406. In this case, the base plate 200 contains at least one discharge opening 404. When the valve is opened, the contents of the working chamber flows out through the discharge hole 404.

In one embodiment, the base plate 200 includes a plurality of discharge openings 404. The discharge openings 404 are arranged to be distributed over the base plate 200. The plural discharge openings 404 collectively have a large cross-sectional area, resulting in faster emptying.

In one embodiment, the transport system 500 for removing the contents of the working chamber from the cavity 406 is located in the cavity 406. For example, the conveyor system 500 may be in the form of a belt or screw conveyor. The transport system 500 has a lift height sufficient to transport the contents to transport containers placed at ground level. The transport container can also be located under the mill in such a way that no transport device is needed.

In FIG. 6 is a flowchart of a vertical ball mill maintenance method 600 in accordance with one embodiment. Using the method 600, it is possible to carry out maintenance on a ball mill, especially for the pre-grinding of minerals. The method 600 includes a split step 602, a set step 606, and an offset step 610.

The vertical ball mill contains a rotor fixed in the axial and radial direction at the upper end and hanging down. In addition, the vertical ball mill contains a stator that surrounds the rotor radially, is not loaded by the mass of the rotor, and is installed without the use of additional elements. The rotor contains a side surface oriented tangentially to the rotor and having an approximately cylindrical shape with a shape tolerance. In addition, the vertical ball mill includes a base plate holding the stator mass. The stator contains at least two stator segments, which can be separated from each other, installed without support separately from each other and move relative to each other. Each of the stator segments comprises at least one side wall edge extending from the top edge of the wall forming the side surface to the bottom edge of the wall, a sealing surface for sealing against the other stator segment in each case. In addition, each of the stator segments has, on its lower edge, a bearing surface, the dimensions of which correspond to the load, and which is intended for sealing against the base plate. The bearing surface of the stator segment uses the bearing surface of the base plate at right angles with angular tolerance.

In a separation step 602, the stator is divided into stator segments, with the stator being separated along the sealing surfaces. To do this, the mechanical connections between adjacent stator segments can be exposed.

At installation step 606, the accessories are installed under the stator segment. In this case, the auxiliaries can be positioned and configured in such a way that the stator segment can fully rest on the auxiliaries and move with them.

At 610 shifting, the stator segment and accessories can be shifted laterally by the shifter. In this case, at least one of the stator segments is shifted substantially horizontally, its mass preferably continuing to be transferred to the base of the ball mill via auxiliary devices.

A ball mill containing a stator which is opened in the manner described above can be easily serviced afterwards. In particular, the working chamber is easily accessible, which makes it possible to clean it and/or replace wearing parts.

In one embodiment, method 600 includes a raise step 604 and a lower step 608. In lifting step 604, at least one of the stator segments is lifted by the lifting devices, the stator segment being lifted off the base plate. It is enough to raise the stator segment by a few millimeters or a few centimeters. The lifting can be carried out from below, in particular by means of hydraulic lifting devices supporting the thrust elements on the respective stator segment. At step 608 lowering the stator segment is lowered onto the accessories.

In the disclosed design of the ball mill stator, said stator rests on a base plate and thus indirectly on the base, which allows the stator to be easily opened, preferably with only a small number of trained personnel and/or under difficult conditions, in order to then be able to service the ball mill. . The design described above allows for faster maintenance. Since the mill can then be quickly returned to the production process again, productivity increases.

In FIG. 7 is a three-dimensional view of a closed vertical ball mill 100 in accordance with one embodiment. In this case, the ball mill 100 essentially corresponds to the ball mill shown in FIG. 1. In addition, the ball mill 100 includes work platforms 700 at several levels, located one above the other, on the frame 108 and on the stator 102. The work platforms 700 are fenced around the perimeter with railings. Stator segments 112 and frame 108 comprise work platforms 700 on two levels. Frame 108 also includes work platforms 700 arranged on two levels. Thus, the ball mill 100 contains four levels.

The work platforms 700 of the stator segment 112 are interconnected by a ladder 702. The ladder 702 is mounted on an inclined support 132, which in this case is permanently installed. Ladder 702 contains a protective fence in the form of a basket. The ramp 132 is connected to both work platforms 700 or to the support structure of the work platforms 700 and is oriented substantially parallel to the longitudinal axis of the stator 102. The ramp 132 is positioned so that it can be placed separately from the stator segment 112 on the work platforms 700. Due to the permanently mounted ramp 132, the stator 102 contains only two thrust members 124 in the area of the sealing flanges 114. A third thrust member 124 is mounted at the lower end of the ramp 132. platforms 700 stator 102.

Access to the work platforms 700 on the frame 108 is through a ladder shaft 704. The ladder shaft is located adjacent to the frame 108. On the third level, the frame 108 contains a maintenance cabin 706 from which a protected access to the coupling between the bearing and drive device 106 and the rotor is possible, as well as to the disconnecting device. The maintenance cabin 706 is surrounded by work platforms 700 at the periphery. .

Frame 108 is made in the form of a wooden frame. In this case, the frame 108 from the side of the stairwell 704 is made in the form of a three-dimensional frame and contains six vertical elements in two parallel rows. On the two lower levels of the frame 108, the work platforms 700 are located on the frame beams connecting the vertical members. In the closed state of the ball mill 100, the stator work platforms 700 are also accessible from the work platforms 700 of the frame 108. From the side opposite the stairwell 704, the frame 108 is made in the form of a flat frame containing three vertical elements in a row.

In FIG. 8 is a three-dimensional view of an open vertical ball mill 100 in accordance with one embodiment. In this case, the ball mill 100 essentially corresponds to the ball mill shown in FIG. 7. For reasons of clarity, the rotor is not shown. In this case, the stator segments 112 are shown separately from each other and offset sideways. Unlike FIG. 1-6, in this case, the base plate 200 is configured to be raised above the surrounding ground surface. The inclined base 402 is made in the form of an inclined end surface of a truncated cylinder protruding beyond the bearing surface 201, that is, protruding into the stator 102 when the ball mill 100 is closed.

Each auxiliary device 134 includes a frame 800 connecting all three thrust elements 124 of the stator segment 112 and fixing their positions relative to each other. Accessory devices 134 can be easily lifted on the frame 800, for example, using a built-in crane, and moved to a storage location. After separating the stator segments 112, lifting of the stator segments 112 on the thrust members 124 was performed to disengage them from the base plate 200. The auxiliaries 134, together with the frame 800, were installed between the locking elements 124 and the shifter 126. The stator segments 112 were then lowered onto the auxiliaries. devices 134. The accessories 134 comprise their own drive 802. Using the drive 802, the accessories 134, together with the stator segments 112 mounted thereon, were moved laterally along the shifter 126 into service positions.

In FIG. 9 is a three-dimensional view of a stator segment 112 of a vertical ball mill in accordance with one embodiment. In this case, stator segment 112 substantially corresponds to one of the stator segments in FIG. 7 and 8. Unlike the stator segments shown in FIGS. 1-5, the stator segment 112 includes only one stiffening rib 117 on the outer surface. Rib 117 stiffness is located in the lower region of the side surface 104 above the axial ribs 119 of the thrust elements 124.

The work platforms 700 are configured to surround the side surface 104. On the inner surface, that is, the side facing the side surface 104, the work platforms 700 comprise a semicircular arcuate cutout for the stator segment 112. On the outside, that is, on the side away from the side surface 104, the work platforms 700 have an angular shape. All external sides of the work platforms 700 are enclosed by railings and thresholds 900. The thresholds 900 protrude upward from the bottom surface of the work platforms 700 and prevent objects from falling.

The work platforms 700 comprise a cutout in the area of the sealing flange 114. Thus, the sealing flange 114 is not interrupted by the work platforms 700. In the cutout area, the work platforms 700 are located on the side of the stator segment 112 behind the plane of the sealing surface 118 or behind the sealing flange 114. Thus, the sealing flange 114 is accessible from both sides, and stator segment 112 can be connected to another stator segment (not shown) in an ergonomic working position.

Ladder 702 is located on one side of the ramp 132 and includes a passage in a basket-shaped enclosure at the height of each of the two work platforms 700. The railing is interrupted in the area of the passages.

In FIG. 10 is a three-dimensional view of the work platform 700 of a vertical ball mill, in accordance with one embodiment. In this case, the work platform 700 substantially corresponds to one of the work platforms in FIG. 7. The work platform 700 has a rectangular shape. Similar to the work platforms in FIG. 9, the work platform 700 is enclosed on two outer sides by thresholds 900 protruding from the bottom surface and railings. Beneath the bottom surface, the work platform 700 includes a supporting structure. In particular, the lower surface is reinforced with ribs. On the two inner surfaces of the work platform 700, the ribs contain mounting holes for attaching the work platform 700 to the ball mill.

Each of the four corners of the work platform 700 is provided with a lifting stop 1000 recessed into the bottom surface. The work platform 700 can be quickly and easily assembled and disassembled using the built-in crane and the 1000 jacks.

In FIG. 11 is a three-dimensional view of a shear device 126 of a vertical ball mill 100, in accordance with one embodiment. In this case, the shifter 126 substantially corresponds to the shifter of FIG. 8. The shifting device 126 is located on the rails 130. The accessories 134 are located between the thrust members 124 and the rails 130. The frame 800 is substantially V-shaped and connects the accessories 134 mounted on the thrust members 124. Each of the two accessories 134, mounted on the segment 112 of the stator, contains the electric drive 802.

In FIG. 12 is a detailed view of the support flange 120 of a vertical ball mill 100, in accordance with one embodiment. The base flange 120 uses a base plate 200. The base plate 200 corresponds to the view in FIG. 8. The support flange 120 and bearing surface 201 comprise grooves 1200 arranged in a uniform pattern. At the same time, the grooves 1200 on the bearing surface 201 are made in the form of T-shaped grooves for receiving T-shaped bolts (not shown in the figure) for screwing the stator 102 to the base plate 200. In the released state, the T-shaped bolts can be removed laterally from the T-bolt. shaped grooves and grooves 1200 of the support flange 120 and, thus, are not an obstacle to the lateral shift of the stator segments 112.

In FIG. 13 is a detailed view of the sealing flange 114 of the vertical ball mill 100, in accordance with one embodiment. The ball mill 100 is closed in this case. In this case, the sealing flanges 114 of the interconnected stator segments 112 are pressed against each other by hinged clamps 1300. The clamps 1300 comprise a main U-shaped main body 1302 and surround both sealing flanges 114 from the outside. On the outer side of one of the segments 112 of the stator are loops 1304, on which the loops of the clips 1300 are fixed, which allows them to rotate in a horizontal plane. Each main body 1302 includes at least one threaded hole 1306 in which a screw spindle 1308 is rotatably mounted to compress the sealing flanges 114.

In one embodiment, the sealing flanges 114 are connected to each other by hinged jaws 1310. The jaws 1310 are mounted on hinges 1304 so that they can be rotated in a horizontal direction. The clamping jaws 1310 include an inclined tapered vertical slot 1312. The slot 1312 is wider than the two sealing flanges 114 combined. At its narrower end, slot 1312 is narrower than the sealing flanges 114. The sealing flanges 114 are inserted into the slot 1312 by turning the jaws 1310. If the sides of the slot 1312 use the sealing flanges 114, then the jaws 1310 can be wedged against the sealing flanges 114, for example , hammer blows. To release the jaws 1310, for example, a wedge can be pushed between the jaws 1310 and side surface 104 to push the jaws 1310 away from the sealing flanges 114.

Finally, it should be noted that terms such as "comprising", "having", etc., do not exclude any other elements or steps, and terms such as "he" or "one" do not exclude the plural. The reference designations in the claims are not to be considered as having a limiting character.

List of reference symbols

100 - ball mill

102 - stator

104 - side surface

106 - bearing and drive unit

107 - electric motor

108 - frame

110 - base

112 - stator segment

114 - sealing flange

116 - wall

117 - tangential stiffeners

118 - sealing surface

119 - axial stiffeners

120 - support flange

121 - through holes

122 - supporting surface

124 - thrust element

126 - shifting device

128 - trajectory of movement

130 - guide

132 - inclined support

134 - auxiliary device

200 - base plate

201 - bearing surface

202 - traction device

204 - rotor

205 - rotor shaft

206 - inner surface

208 - rib

210 - braking surface

212 - disk

213 - holes

214 - loading surface

215 - knitting needles

216 - clutch

218 - disconnecting device

220 - connecting device

222 - latch

400 - unloader

402 - inclined base

404 - discharge hole

406 - cavity

408 - flush hole

500 - transport system

600 - vertical ball mill maintenance method

602 - separation stage

604 - lifting stage

606 - installation step

608 - lowering stage

610 - offset stage

700 - working platform

702 - stairs

704 - stairwell

706 - maintenance cabin

800 - frame

802 - drive

900 - thresholds

1000 - lifting stop

1200 - groove

1300 - clamp

1302 - main building

1304 - loop

1306 - threaded hole

1308 - screw spindle

1310 - clamping jaws

1312 - slot

Claims (17)

1. Vertical ball mill (100) designed for preliminary grinding of minerals, containing: a rotor (204), fixed in the axial and radial direction at the upper end and hanging down, a stator (102), radially surrounding the rotor (204), not loaded with mass rotor (204), installed without the use of additional elements and having a side surface (104) oriented tangentially to the rotor (204) and having a cylindrical shape with a tolerance for the shape, and a base plate (200) holding the stator mass (102), moreover stator (102) contains at least two stator segments (112) separated from each other, installed without support separately from each other and movable relative to each other, each of the stator segments (112) contains at least one side edge of the wall ( 116) extending from the upper edge of the wall (116) forming the side surface (104) to the lower edge of the wall (116), the sealing surface (118) for sealing against the other segment (112) of the stator in each case, and on the lower edge - bearing surface (122) with dimensions corresponding to the load and intended for sealing relative to the base plate (200), wherein the segment (112) of the stator uses the bearing surface (122) as a support on the bearing surface (201) of the base plate (200) at a right angle with angle clearance. 2. Ball mill (100) according to claim 1, in which several horizontal ribs (208), located at a distance from each other vertically and having the shape of a ring segment, are provided on the inner surface (206) of the walls (116), moreover, on the assembled the stator (102) ribs form inwardly protruding annular braking surfaces (210), and the rotor (204) contains several horizontal disks (212) located vertically apart from each other, each of them having an external annular loading surface (214), moreover, the ribs (208) and discs (212) are arranged alternately in the vertical direction and the braking surfaces (210) and loading surfaces (214) can be overlapped, at least partially, in the horizontal direction. 3. Ball mill (100) according to one of the previous paragraphs, in which on the outer side of each stator segment (112) thrust elements (124) are provided for lifting and moving the corresponding stator segment (112). 4. Ball mill (100) according to claim 3, in which each segment (112) of the stator in the region of the lower edge of the wall (116) contains thrust elements (124) designed for mounting hydraulic jacks. 5. Ball mill according to one of paragraphs. 3, 4, in which the stop elements (124) define the corner points of a virtual horizontal polygon, in particular a triangle; its geometric center is located on a vertical axis passing through the center of gravity of the standing segment (112) of the stator. 6. Ball mill (100) according to one of paragraphs. 3-5, containing a shear device (126) for lateral displacement of the stator segments (112) separated from each other, and the shear device (126) contains movable auxiliary devices (134) designed to be installed between the thrust elements (124) and guides (130 ) located on the ground and oriented parallel when the stator segment (112) is raised, and to move along the guides (130) together with the stator segment (112) laid on them. 7. Ball mill (100) according to claim 6, in which the shear device (126) contains at least one inclined support (132) for using a thrust element (124) installed at a distance from the vertical from the support surface (122) at least measure on one of the rails (130) to prevent tilting of the stator segment (112) during lifting and shifting. 8. Ball mill (100) according to one of paragraphs. 6, 7, in which the guides (130) are recessed into the base (110) of the ball mill (100) and can be additionally covered with protective devices during the period when they are not used. 9. Ball mill (100) according to one of the previous paragraphs, containing an unloading device (400) for emptying the ball mill (100). 10. Ball mill (100) according to claim 9, in which the unloader (400) contains an inclined base (402) within the bearing surface (201) of the base plate (200), and one of the segments (112) of the stator contains an unloading hole ( 404) of the unloader (400) in the area of the lower point of the inclined base (402). 11. Ball mill (100) according to claim 10, in which one of the segments (112) of the stator contains a flushing hole (408) of the unloader (400) in the region of the upper point of the inclined base (402). 12. Ball mill (100) according to one of the previous paragraphs, containing a frame (108) separated from the stator (102), and the frame supports (108) are used as a support for the base (110) of the ball mill (100) with a side shift from the stator (102) and at least one cross beam of the frame (108) connects the supports above the stator (102), with the bearing and drive device (106) of the rotor (204) being used as a support on the cross beam. 13. Ball mill (100) according to one of the previous paragraphs, containing a disconnect device (218) for lateral disconnection of the rotor (204), which can be disconnected from the upper sleeve (216), and the disconnect device (218) contains at least one guide (130) and a connecting device (220), moreover, the connecting device (220) is intended for connection with the rotor (204) in the area of the coupling (216), for lowering onto the guide (130) together with the rotor (204) and moving along the guide (130 ) together with the rotor (204). 14. Ball mill (100) according to paragraphs. 12 and 13, the frame (108) comprising a maintenance cabin (706) in the area of the clutch (216). 15. Segment (112) of the stator for a vertical ball mill (100) according to one of paragraphs. 1-14, installed without the use of additional elements, containing: a wall (116) having the shape of a cylinder segment within the shape tolerance, at least one sealing surface (118) located on the side edge of the wall (116), extending from the upper edge wall (116) to the lower edge of the wall (116) and intended for sealing against another segment (112) of the stator, and a support surface (122) located on the lower edge and having dimensions corresponding to the load, with which the segment (112) of the stator can be installed on the bearing surface (201) of the base plate (200) of the ball mill (100) at a right angle with an angular tolerance, and the stator (102) installed without the use of additional elements and having a side surface (104) formed by walls (116) and having shape-tolerant cylinder shape may comprise several stator segments (112), wherein the assembled stator may rest on a base plate (200) supporting the mass of the stator (102). 16. Method (600) for dismantling the stator of a vertical ball mill (100) intended for preliminary grinding of minerals, wherein the vertical ball mill (100) comprises a rotor (204) fixed in the axial and radial direction at the upper end and hanging down, a stator (102 ), radially surrounding the rotor (204), not loaded by the mass of the rotor (204), installed without the use of additional elements and having a side surface (104) oriented tangentially to the rotor (204) and having a cylindrical shape with a shape tolerance, and a base plate (200), which uses as a support the mass of the stator (102), and the stator (102) contains at least two segments (112) of the stator, separated from each other, installed without support separately from each other and movable relative to each other, and each of the segments (112) of the stator contains at least one side edge of the wall (116) extending from the upper edge of the wall (116), forming the side surface (104), to the lower edge of the wall (116), sealing surface (118) for sealing relative to the other segment (112) of the stator in each case, and on the lower edge - the bearing surface (122) with dimensions corresponding to the load and intended for sealing against the base plate (200), and the segment (112) of the stator uses the bearing surface (122) in as a support on the bearing surface (201) of the base plate (200) at a right angle with an angular tolerance, and the method (600) comprises: dividing (602) the stator (102) into stator segments (112), and the stator (102) is divided along the sealing surfaces (118), installation (606) of auxiliary devices (134) under at least one of the stator segments (112) and side displacement (610) of the stator segment (112) and auxiliary devices (134) using a shifting device (126). 17. The method (600) of claim 16, wherein the stator segment (112) can be lifted off the base plate (200) using lifting devices and placed on the accessories (134) using lifting devices.

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