WO2023141730A1

WO2023141730A1 - Device, system and method for draining liquids from inside mills

Info

Publication number: WO2023141730A1
Application number: PCT/CL2022/050010
Authority: WO
Inventors: Juan Patricio MURA ULLOA; Eric Edgardo JORQUERA GALLARDO; Diego Ignacio NUÑEZ CUEVAS; Mauricio Hernán SEGOVIA SEDÁN
Original assignee: Compañía Electro Metalúrgica S.A.
Priority date: 2022-01-28
Filing date: 2022-01-28
Publication date: 2023-08-03

Abstract

The present invention relates to a device, system and method that allow liquids to be drained from inside mills without needing to dismantle the interior liners.

Description

DEVICE, SYSTEM AND METHOD FOR DRAINING LIQUIDS FROM THE INTERIOR OF MILLS

FIELD OF THE INVENTION

The present invention relates to the mining industry. In particular, the present invention relates to a device, system and method that allows liquids to be drained from inside the mills without the need to dismantle the interior linings.

STATE OF THE ART

Currently in the mining industry, specifically in semi-autogenous mills (SAG) and ball mills, the water must be evacuated inside the mills when carrying out maintenance, emergency stops or scheduled stops, in order to improve the safety and cleanliness conditions for the work of the personnel and equipment used.

At present, the drainage of water is done by removing some interior linings of the mill to uncover the anchoring holes in the body of the mill, so that the water drains through the holes by the action of gravity. The procedure described is high risk, since it requires operators and machinery to enter the interior of the mill to remove the linings, since inside the mill there are rocks, grinding elements mixed with water and mud, so the workers and machinery are at risk of slipping or being struck by rocks and grinding media that slide or fall from the top of the mill body. This procedure requires valuable extra time, additional maneuvering procedures and equipment, and involves additional risks for workers removing the liners.

Various alternatives have been found in the state of the art, which partially solve the technical problem posed.

Within what is known is the publication EP1027934A1, which discloses a mill where the outer casing of the mill is made up of at least two components of the casing fixed to each other by fixing elements and removable from each other where a closing element in the outlet of the grinding casing allows the drainage of the grinding media which can be filled into it. However, the type of gates described in this publication is not applicable to semi-autogenous mills or ball mills, since the gate is constantly hit by the material inside the mill, so it will eventually end up failing due to wear and plastic deformation. Additionally it is noted that prior art technology does not allow draining the mill from any position, but requires rotating the body of the mill to specific positions, which is disadvantageous.

Another document is publication US3001730A, which discloses a spherical mill instead of a drum or cylindrical type, and having two duplicate sections arranged to be joined to complete the mill enclosure with each section comprising an integral set of shell portions. and liner, including a weep hole with inner liner and a hinge. However, this type of gate is not compatible with the mill linings required in semi-autogenous mills or ball mills and is an element directly exposed to wear caused by the material inside the mill, which is why the gate ends up failing. due to wear and plastic deformation. Additionally it is noted that prior art technology does not allow draining the mill from any position, but requires rotating the body of the mill to specific positions, which is disadvantageous.

To correct the problem, a mill drainage system is required that allows liquids to be drained from inside the mill without having to dismantle the interior linings, that does not alter the structure of the mantle of the body of the mill and that is compatible with the shapes of inner linings used in the art.

SUMMARY DESCRIPTION OF THE INVENTION

In view of the above, a drainage system is proposed that can be used in conjunction with mill linings with external bolting and would allow not having to remove linings, since it is installed in the same perforations available in the mantle for fastening the pipes. linings, generating a fluid connection between the interior of the mill and the exterior of the mill. To achieve this, an elongated drainage device is used that is installed in the free perforations of the mill body, allowing the use of a suction pump or water impulsion to drain more quickly than with conventional methods, it does not require removing linings to the draining operation, and reduces the times of evacuation of water and associated procedures.

The proposed drainage system contains components that are easy to replace compared to prior art and can be implemented in all the individual lining elements inside the mill, allowing system availability. proposed drain in whatever position is required. Another advantage in this regard is related to the fact that the proposed invention presents the alternative of being used by evacuation in series, allowing draining from multiple areas of the mill at the same time, which leads to further improvement in evacuation times.

Additionally, the proposed drainage system allows connection to pumps and systems for cleaning, purifying and/or collecting drained water to be reused as required.

DESCRIPTION OF THE FIGURES

Figure 1 shows a schematic view in longitudinal section of a mill lining of the state of the art.

Figure 2 shows a schematic view in longitudinal section of an exemplary embodiment of the present technology.

Figure 3 shows a schematic cross-sectional view of an exemplary embodiment of the present technology showing a drainage device and an anchor bolt.

Figure 4 shows a schematic cross-sectional view of an exemplary embodiment of the present technology where two drainage devices can be seen in the same cross section.

Figure 5 shows a schematic sectional view of an exemplary embodiment of a drainage device of the present technology.

Figure 6 shows a schematic sectional view of various components of an exemplary embodiment of a drainage device of the present technology.

Figure 7 shows a schematic sectional view of a mill where multiple drainage devices have been installed at various points around its circumference, where a water extraction system can also be seen using pumps.

DETAILED DESCRIPTION OF THE INVENTION

The present invention describes a drainage system that allows liquids and water to be drained from the interior of semi-autogenous mills, rod mills and ball mills without the need to remove the liners for the draining operation, and which also reduces evacuation times. of water and associated procedures. To achieve this, the present technology takes advantage of pre-existing anchor holes in the shell of the mills, which are commonly used to insert anchor bolts that hold the interior linings of the mill. Usually the mantle of the mill body has more anchor holes than those required to support the linings. It is in these additional anchor holes that the present technology introduces a drainage device comprising an elongated and hollowed-out drainage body that fluidly connects the interior of the mill with the exterior.

The drainage bodies are inserted into the anchoring holes of the mill body and are fastened to the interior linings by means of threaded connections at a first end of the drainage body, these connections being the same ones used to insert the bolts that hold the drainage bodies. inner linings, that is, they can be the fastening nuts of the mill linings.

On the other hand, to be able to hold the drainage bodies, torque must be applied to the drainage bodies, for this purpose the drainage bodies also comprise a clamping area that is outside the mantle of the mill body that can have a hexagonal cross section , triangular, square, pentagonal, other regular polygon shape or shape with opposite parallel faces, this section allows to hold the drain body using wrenches or other tools.

In order to prevent liquids from leaving the interior of the mill through the drainage device during normal operation of the mill, the drainage devices include a lid, plug or plug cover that is coupled to a second end of the drainage body, which closes the external outlet of the drainage body. The plug cover is attached to a second threaded end next to the fastening area and it is in this same second threaded end where different types of couplings can also be connected to connect hoses and hydraulic pumps directly to the drainage body, allowing for better extraction. of fluids and allowing them to be redirected towards containers or towards operations where water or liquids can be reused. The plug cover may have a hexagonal, triangular, square, pentagonal, other regular polygonal shape, or shape with opposite parallel faces for ease of installation and removal.

In other embodiments of the present invention, the second end of the drainage bodies comprises connection means other than threaded connections, allowing hoses or ducts to be coupled.

To improve the operation of the system, the mill linings comprise one or more drainage perforations that open out at the end of the drainage body located inside the mill. In an alternative embodiment, employing two or more drain perforations improves drainage of liquid or water from the inside the mill, because in case any of the perforations are covered by stones, ground material, or other, the uncovered perforations allow to continue draining through the drainage body.

Using the described system, when draining the liquids inside the mill, it is no longer necessary to introduce personnel into the mill, nor is it necessary to dismantle the interior linings, which can weigh several tons each, but rather all the cleaning can be done. operation from abroad. For this, the lid or plug cover of the drainage devices must be removed and after the drainage devices must be oriented towards the lower quadrant of the mill, then it is possible to drain the water through the drainage devices using the force of gravity. or by driving suction or impulsion hydraulic pumps.

Depending on the grinding material, it is possible that fine particles enter the interior of the cavity of the drainage body, and may even block the outlet of the liquids, so when removing the plug cover, the cavity of the body is cleaned drainage using brushes, scrapers or inserting rods. In other embodiments, to prevent clogging of the cavity of the drainage body, an elongated interior body with a substantially similar or equivalent shape to that of the interior of the cavity is introduced inside it, thus preventing material from accumulating in the cavity, reducing clogging and reducing drainage times. In other exemplary embodiments, the inner body is coupled with the stopper cover, and may even form a single body.

Another of the advantages provided by this system is that it allows the water extracted from the mill to be channeled and redirected to reuse it in another activity, thereby reducing the amount of water required throughout the operation of a mill.

With reference to figure 1, a schematic view in longitudinal section of a mill lining system of the state of the art is shown, where a mill lining 200 is observed attached to a mill body 300 by means of fastening bolts 203 installed through anchor holes 301 . In technologies such as the one illustrated in figure 1, to drain the interior of the mills, some of the mill linings 200 must be removed, extracting the anchor bolts 203 and introducing equipment and people inside the mill body 300 still loaded with rocks, water, mud and grinding elements such as balls or steel bars. This type of drainage operations are considered high risk, since the personnel must enter a dark closed chamber with slippery surfaces where they also tend to detach rocks from the linings located in the upper part of the mantle of the mill body 300.

In contrast to the above, Figure 2 shows a schematic view in longitudinal section of an exemplary embodiment of the present technology, where a drainage device 100 is observed installed in one of the anchor holes 301 that were previously kept empty, allowing fluid connection between the interior and exterior of the mill body 300 through drainage perforations 201, without the need to structurally modify the mill body 300 and without the need to loosen or remove mill liners 200.

Referring to Figure 3, a schematic cross-sectional view of an exemplary embodiment of the present technology is shown showing a drainage device 100 and an anchor bolt 203 connected to clamping nuts 202 of the mill lining 200. It can be seen that the mill lining 200 associated with the present technology can have multiple drainage perforations 201, which can lead to a drainage device 100 or to an anchor bolt 203, which allows one or more to be used, as necessary. more 203 anchor bolts can be replaced by 100 drainage devices to reduce drainage times. Similarly, if the load stress to which the mill linings 200 are subjected increases, it is possible to replace drainage devices 100 with anchor bolts 203 to improve the holding of the mill lining 200, improving safety and reducing the probability of a coating coming off. Additionally, to improve the attachment to the mill, the drainage devices are installed using washers 204 like those usually used in anchor bolts 203.

Referring now to figure 4, it shows a schematic cross-sectional view of an exemplary embodiment of the present technology where two drainage devices 100 can be seen in the same cross section. It is also observed that some drainage devices also include an internal body 106 that prevents clogging inside the drainage device 100, which allows the interior of the mill to be drained more quickly, since in drainage devices that do not have an internal body 106 Interior cleaning may be necessary before using the drainage system. Finally, it is also noted that the drainage perforations 201 can have an inclination or an inclined section with respect to the central axis of the drainage devices 100 to prevent liquids from settling inside the mill. On the other hand, Figure 5 shows a schematic view in section of an exemplary embodiment of a drainage device 100 of the present technology where two or more drainage perforations 201 are included, which allows improving the drainage of liquids from the inside. of the mill, because in the event that a rock, mud or other material clogs one of the drainage holes 201, it will still be possible to drain the water through the drainage device 100 since the liquids will continue to flow through the drainage holes 201 that are kept uncovered. Figure 5 also shows how the plug cover 108 engages with a second threaded end 104, leaving free access for manipulation of the fastening area 105.

In figure 6(a) an exemplary embodiment of the drainage device 100 of the present technology is observed, while figure 6(b) shows the general shape of the drainage body 101 and indicates the position of a first threaded end 103 which is the one that engages with the threaded surface of the fastening nuts 202 of the aforementioned mill liners. Also noted is cavity 102, which may have a circular or polygonal cross section to facilitate insertion of an inner body 106.

On the other hand, figure 6 (c) shows an inner body 106 that can also include an inner seal 107 that seals the space between the inner body 106 and the cavity 102 to prevent liquids from entering said space and to prevent the entry of sludge and solid materials, reducing clogging and facilitating mill drainage.

For its part, Figure 6 (d) shows a plug cover 108 with a threaded connection inside, where the larger threaded connection is used to connect the plug cover 108 to the threaded end 104, while the smaller threaded connection allows a detachable inner body 106 to be coupled. The threaded connections can have their helical orientation in the same direction, but preferably they have opposite directions between them. It is also appreciated that the plug cover 108 can also contain an outer seal 109 in the shape of a ring that allows sealing the space between the plug cover 108 and the edge of the threaded end 104 of the drain body 101 .

Figure 6(e) illustrates an alternative embodiment of the present technology, where the plug cover 108 and the inner body 106 are united in a single body.

Figure 7 shows a schematic sectional view of a stopped mill, where it can be seen that the material inside the mill separates into two main phases, in the upper part remains a phase made up mainly of grinding liquid 302 formed by water and grinding fluids, and a second denser phase in the lower part formed by the solid grinding material that settles in the form of solid elements, sludge, water and grinding liquids.

Figure 7 also shows an exemplary embodiment where multiple drainage devices 100 have been installed at various points around the circumference of the mill body 300, which allows the drainage system to be used in any rotation position of the mill, eliminating the need to rotate the mill body to specific positions to drain. In the embodiment illustrated in Figure 7, one or more drain devices 100 located below the grinding liquid level 302 may be uncovered to allow fluids and water within the mill to be drained out by the action of the mill. the force of gravity.

Still referring to Figure 7, drain devices 100 located below the grinding liquid level 302 can also be connected to hoses 304 to direct the extracted fluids and water, where in an alternative embodiment of the present technology, the hoses can be connected to 305 pumps that allow to reduce the times required to drain the fluids and water from inside the mill. In a preferred embodiment, two or more hoses 304 are connected to each other by a connector 306 that is in fluid connection with one or more pumps 305 to reduce the times required to drain fluids and water from inside the mill. Although any of the drainage devices 100 located below the grinding liquid level 302 can be connected to pumps 305, it has been observed that the extraction of the fluids and the water inside the mill by means of pumps is carried out more quickly when the pumps 305 connect fluidly with drainage devices 100 that are located above the level of accumulated grinding material 303 .

In a preferred embodiment, the present technology refers to a drainage system for draining liquids from inside a mill body 300 comprising: a mill lining 200 with at least one fastening nut 202 and at least one drainage perforation 201, wherein the mill liner 200 is positioned on the inner surface of the mill body 300; at least one drainage device 100 comprising a drainage body 101 that passes through the mill body 300, wherein the drainage body 101 has a cavity 102, a first threaded end 103 that engages with the clamping nut 202, a clamping zone 105 located on the outside of the mill body 300; and a plug cover 108 that fits into a second end 104 of the drainage body 101; wherein the cavity 102 of each drainage body 101 is in fluid connection with the at least one drainage perforation 201 .

In an embodiment of the present technology, the drainage device further comprises a removable inner body 106 that is housed in the cavity 102 of the drainage body.

In another embodiment of the present technology the inner body 106 is coupled to the plug cover 108.

In another embodiment of the present technology the inner body 106 and the stopper cover 108 form a single body.

In another embodiment of the present technology the inner body 106 further comprises an inner seal 107 and the plug cover 108 further comprises an outer seal 109.

In another embodiment of the present technology the second end 104 is a threaded end.

In another embodiment of the present technology the second end 104 further comprises a hose coupling.

In another embodiment of the present technology, the clamping zone 105 has a hexagonal, triangular, square, pentagonal, regular polygonal, or a shape with opposite parallel faces.

In another embodiment, the present technology refers to a drainage method for draining liquids from inside a mill body 300 comprising the steps of: providing in the mill body 300 at least one drainage device 100 comprising a body drainage 101 passing through the mill body 300, wherein the drainage body 101 has a cavity 102, a first threaded end 103, a second end 104 and a clamping area 105 adjacent to the second end 104; and a stopper cover 108 that is coupled to the second end 104 of the drainage body 101; wherein the cavity 102 fluidly connects the inside of the mill body with the outside; removing the plug cover 108 from at least one of the drainage devices 100 in the lower quadrant of the mantle of the mill; and drain the liquids from inside the mantle of the mill.

In another embodiment of the present technology the step of removing the plug cover 108 further comprises cleaning and uncovering the interior cavity 102. In another embodiment of the present technology, the step of removing the stopper cover 108 further comprises removing a removable inner body 106 that is housed in the cavity of the drainage body 101 .

In another embodiment of the present technology, after removing the plug cover 108, it further comprises the step of connecting a hydraulic pump 305 in fluid connection with the at least one drainage hole 201 through the second end 104 of the drainage body 101; and wherein the step of draining the liquids further comprises activating the hydraulic pump 305 to suck the liquids.

In another embodiment of the present technology the step of removing the plug cover 108 further comprises rotating the mill mantle locating the drainage device 100 in the lower quadrant of the mill mantle.

APPLICATION EXAMPLE

In an exemplary embodiment, the present technology was used in tests to drain liquids from within a ball mill at a mining facility. From the mill stoppage operation records, it can be seen that, using the conventional methodology that includes removing some linings from the mill, the drainage operation took between 10 and 12 hours, taking an average of 11.2 hours.

In a first set of tests, the mill in question had 208 drainage devices installed around the entire perimeter of the mill. Subsequently, the time required to drain the liquids inside was timed using only the force of gravity, observing that the drainage operation took between 7 and 9 hours, taking an average of 7.9 hours.

In a second set of tests carried out in the same mill, hydraulic pumps were connected to the drainage devices and then turned on to more quickly suck the liquids inside, observing that the drainage operation took between 1 and 2 hours. taking an average of 1.6 hours.

Therefore, from this example it can be seen that the present technology reduces the average time required for the draining operation by 29.5%, draining only by gravity with 208 drainage devices distributed around the perimeter of the mill and by 85.7 % when used together with hydraulic pumps, in addition to allowing the draining operation to be carried out without the need for personnel to enter the mill and without the need to remove lining plates.

REFERENCE NUMBERS In order to clarify the present description, a list with the components of the invention and their respective reference numbers is included below.

100 drainage device

101 Drain body

102 cavity

103 First End

104 Second End

105 Clamping Zone

106 Inner body

107 inner seal

108 Plug cover

109 Outer Seal

200 mill lining

201 Drainage drilling

202 Clamping nut

203 Anchor bolt

204 Golilla

300 mill body

301 Anchor Drilling

302 Grinding water

303 Material in grinding

304 Hoses

305 Bomb

306 collector

Finally, it should be noted that the different particular parameters of the invention, such as the dimensions, the choice of materials, and specific aspects of the preferred configurations described above can be varied or modified depending on the operating requirements. Accordingly, the specific configurations described above are not intended to be limiting, and such variations and/or modifications are within the spirit and scope of the invention.

Claims

1 - A drainage system for draining liquids from inside a mill body (300) comprising: a mill lining (200) with at least one fastening nut (202) and at least one drainage hole (201) , wherein the mill liner (200) is positioned on the inner surface of the mill body (300); at least one drainage device (100) comprising a drainage body (101) that passes through the mill body (300), wherein the drainage body (101) has a cavity (102), a first end (103) threaded that engages with the clamping nut (202), a clamping zone (105) located on the outside of the mill body (300); and a stopper cover (108) that is coupled to a second end (104) of the drainage body (101); wherein the cavity (102) of each drainage body (101) is in fluid connection with the at least one drainage perforation (201).

2- The drainage system according to claim 1 wherein the drainage device further comprises a removable inner body (106) that is housed in the cavity (102) of the drainage body.

3- The drainage system according to claim 2 wherein the inner body (106) is coupled to the stopper cover (108).

4- The drainage system according to claim 2 wherein the inner body (106) and the stopper cover (108) form a single body.

5- The drainage system according to claim

wherein the inner body (106) further comprises an inner seal (107) and the plug cover (108) further comprises an outer seal (109).

6- The drainage system according to claim 1 wherein the second end (104) is a threaded end.

7- The drainage system according to claim 1 wherein the second end (104) further comprises a coupling for hoses.

8- The drainage system according to claim 1 wherein the clamping area (105) has a hexagonal, triangular, square, pentagonal, regular polygonal cross section or a shape with opposite parallel faces.

9- A drainage device (100) to drain liquids from inside a mill body (300) comprising: a drainage body (101) that goes through the mill body (300), wherein the drainage body (101) has a cavity (102), a first threaded end (103), a second end (104) and a zone clamp (105) adjacent to the second end (104); and a stopper cover (108) that is coupled to the second end (104) of the drainage body (101); wherein the cavity (102) fluidly connects the ends of the drainage body (101).

The drainage device (100) according to claim 9, wherein the drainage device further comprises a removable inner body (106) that is housed in the cavity of the drainage body.

1 1 - The drainage device (100) according to claim 10 wherein the inner body (106) is coupled to the plug cover (108).

12- The drainage device (100) according to claim 10, wherein the inner body (106) and the stopper cover (108) form a single body.

13- The drainage device (100) according to claim 9 wherein the second end (104) is a threaded end

14- The drainage device (100) according to claim 9, wherein the clamping area (105) has a hexagonal, triangular, square, pentagonal, regular polygonal cross section or a shape with opposite parallel faces.

15- The drainage device (100) according to claim 9 wherein it further comprises a grommet (107) adjacent to the clamping area (105).

16- A drainage method for draining liquids from inside a mill body (300) comprising the steps of: providing in the mill body (300) at least one drainage device (100) comprising a drainage body (101) that goes through the mill body (300), where the drainage body (101) has a cavity (102), a first threaded end (103), a second end (104) and a fastening area (105). ) adjacent to the second end (104); and a stopper cover (108) that is coupled to the second end (104) of the drainage body (101); wherein the cavity (102) fluidly connects the inside of the mill body with the outside; remove the plug cover (108) from at least one of the drainage devices (100) in the lower quadrant of the mantle of the mill; and drain the liquids from inside the mantle of the mill.

17- The drainage method according to claim 16 wherein the step of removing the plug cover (108) further comprises cleaning and uncovering the interior cavity (102). 18- The drainage method according to claim 16, wherein the step of removing the plug cover (108) further comprises removing a removable inner body (106) that is housed in the cavity of the drainage body (101).

19- The drainage method according to claim 16 wherein after removing the plug cover (108) it also comprises the step of connecting a hydraulic pump (305) in fluid connection with the at least one drainage hole (201) through of the second end (104) of the drainage body (101); and wherein the step of draining the liquids further comprises activating the hydraulic pump (305) to suck the liquids.

20- The drainage method according to claim 16 wherein the step of removing the plug cover (108) further comprises rotating the mill mantle locating the drainage device (100) in the lower quadrant of the mill mantle.