CN215613052U

CN215613052U - Ore washing device

Info

Publication number: CN215613052U
Application number: CN202121418797.9U
Authority: CN
Inventors: 彭翔龙; 谢克炜; 梁用全
Original assignee: Dongguan Wuquan Machinery Co ltd
Current assignee: Dongguan Wuquan Machinery Co ltd
Priority date: 2021-06-24
Filing date: 2021-06-24
Publication date: 2022-01-25
Anticipated expiration: 2031-06-24

Abstract

The utility model discloses an ore washing device, which comprises a mounting plate, a cleaning barrel rotatably arranged on the mounting plate, and a driving mechanism arranged on the mounting plate, wherein the cleaning barrel comprises a feeding barrel, a cleaning barrel and a discharging barrel which are communicated, the feeding barrel is provided with a feeding hole for receiving ores and cleaning liquid, a plurality of discharge openings are uniformly distributed in the circumferential direction of the opposite rear end of the cleaning barrel, the cleaning liquid and silt are discharged from the discharge openings, the discharging barrel comprises a plurality of material distributing openings uniformly distributed on the barrel wall of the opposite rear end of the discharging barrel and a discharging hole arranged at the end part of the discharging barrel, the cleaning barrel on the mounting plate or the mounting plate is obliquely arranged, so that the feeding hole is higher than the material distributing openings and the discharging hole, the driving mechanism can drive the cleaning barrel to rotate, so that the ores roll from the feeding hole to the material distributing openings and the discharging hole, and are repeatedly washed by the cleaning liquid in the rolling process, and the ores with relatively small and large diameters and the large diameters are respectively discharged from the material distributing openings and the discharging hole, the device has the advantages of simple structure, small occupied area, good cleaning effect and high utilization rate.

Description

Ore washing device

Technical Field

The utility model relates to the technical field of ore mining, in particular to an ore washing device.

Background

The ore has many impurity at the back surface of exploiting out, be silt or like the material of silt mostly, when using these ore metallurgy, if it is that surperficial impurity does not get rid of totally, then can influence follow-up crushing to the ore, gravity select, the magnetic separation, operation such as flotation and refining, and then have very big influence to the product that refines, consequently, before ore processing, need be with impurity sanitization such as silt on its surface to avoid the argillaceous thing in the silt mineral raw materials to block up crushing and screening plant.

Therefore, there is a need for an ore washing device with simple structure, small floor space, good cleaning effect and high utilization rate to clean the ore.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an ore washing device which is simple in structure, small in occupied area, good in cleaning effect and high in utilization rate.

In order to achieve the purpose, the utility model discloses an ore washing device, which comprises a mounting plate, a cleaning barrel and a driving mechanism, wherein the cleaning barrel is rotatably arranged on the mounting plate, the driving mechanism is arranged on the mounting plate and is connected with the cleaning barrel, the cleaning barrel comprises a feeding barrel, a cleaning barrel and a discharging barrel which are sequentially communicated along the longitudinal direction of the cleaning barrel, the feeding barrel is provided with a feeding hole for receiving ore and cleaning liquid, the cleaning barrel is provided with a certain length, a plurality of discharge openings are uniformly distributed on the cleaning barrel in the circumferential direction of the opposite rear end of the cleaning barrel, the cleaning liquid and silt are discharged from the discharge openings, the discharging barrel comprises a plurality of discharge openings uniformly distributed on the barrel wall of the opposite rear end of the discharging barrel and discharge openings arranged at the end part of the discharging barrel, the cleaning barrel on the mounting plate or the mounting plate is obliquely arranged, so that the feeding hole is higher than the discharge openings and the discharge openings, and the driving mechanism can drive the cleaning barrel to rotate, so treat abluent ore by the feed inlet towards divide the material mouthful to reach the direction of discharge gate rolls, and washes repeatedly through the washing liquid at the in-process that rolls, washs back diameter size ore that is little relatively by divide the material mouthful ejection of compact, diameter size ore that is big relatively by the discharge gate ejection of compact.

Compared with the prior art, the cleaning barrel of the ore washing device provided by the utility model comprises a feeding barrel, a cleaning barrel and a discharging barrel which are sequentially communicated, cleaning liquid for ores to be cleaned and cleaning ores enters the feeding barrel from a feeding hole of the feeding barrel, the cleaning liquid passes through a cleaning barrel with a certain length and is discharged from a material distributing port and a material discharging port of the discharging barrel, the cleaning barrel is obliquely arranged on the mounting plate or the mounting plate, so that the feeding hole is higher than the material distributing port and the material discharging port, therefore, when the cleaning barrel rotates under the driving of the driving mechanism, the ores roll towards the material distributing port and the material discharging port from the feeding hole in the cleaning barrel under the action of self gravity and the rotating force of the cleaning barrel, so that the comprehensive washing is realized in the rolling process, and the cleaning effect is better; the cleaned cleaning liquid and silt are discharged from a plurality of discharge openings which are uniformly distributed at the circumferential direction of the opposite rear end of the cleaning barrel, most of the cleaning liquid attached to the surface of the cleaned ore is thrown off to be discharged from the discharge openings in the rotating process, the liquid and silt discharging speed is high, and the silt is discharged at the position relatively far away from the discharge openings and the discharge openings by combining the material distributing openings and the discharge openings which are arranged at the opposite rear end of the discharging barrel, so that the finally discharged ore is cleaner; in addition, the plurality of distributing openings are uniformly distributed on the cylinder wall of the discharging cylinder body, the discharging opening is formed in the end portion of the discharging cylinder body, so that ores with relatively small diameter sizes after being cleaned can be screened and discharged through the distributing openings, and ores with relatively large diameter sizes are discharged through the discharging opening, and accordingly primary screening of the ores is achieved.

Preferably, a plurality of first blades are uniformly distributed on the inner circumferential wall of the feeding cylinder body, the first blades are spirally arranged to form a centrifugal force, and a plurality of second blades which are arranged at intervals are respectively arranged on the inner circumferential wall of the cleaning cylinder body and the inner circumferential wall of the opposite front end of the discharging cylinder body.

Preferably, the cleaning cylinder comprises three cleaning sections and a water leakage section which are sequentially communicated, and the drain outlet is arranged on the water leakage section.

Preferably, the discharging barrel comprises a receiving section and a screening section which are communicated, the receiving section is communicated with the cleaning barrel, and the material distributing opening and the material outlet are correspondingly arranged on the barrel wall and the end part of the screening section.

Preferably, the driving mechanism comprises a driving motor, a gear connected to the output end of the driving motor, and a gear ring convexly arranged on the peripheral wall of the cleaning cylinder, the gear ring is meshed with the gear, and the driving motor can drive the gear to rotate, so that the gear ring drives the cleaning cylinder to rotate along with the gear ring.

Preferably, the ore washing device further comprises at least two supporting assemblies arranged on the mounting plate in parallel and at intervals, each supporting assembly comprises two supporting seats symmetrically arranged on the mounting plate by taking the cleaning cylinder as a center, two rollers correspondingly arranged on the two supporting seats one by one, and a roller ring convexly arranged on the peripheral wall of the cleaning cylinder, a guide groove corresponding to the shape of the roller ring is arranged on the peripheral wall of the roller, and the roller ring is rotatably erected in the guide grooves of the two rollers opposite to the roller ring.

Preferably, the driving mechanism is located at the opposite center of the mounting plate, the opposite front end, the opposite center and the opposite rear end of the mounting plate are respectively provided with one of the supporting components, and the supporting components located at the opposite center of the mounting plate are arranged in a staggered manner with the driving mechanism.

Preferably, the material distribution port includes a first sieve distribution port, a second sieve distribution port and a third sieve distribution port which are sequentially arranged along the longitudinal direction of the discharge cylinder, the number of the first sieve distribution port, the number of the second sieve distribution port and the number of the third sieve distribution port are all plural, the plural first sieve distribution ports, the plural second sieve distribution ports and the plural third sieve distribution ports are respectively and uniformly arranged in the circumferential direction of the cylinder wall of the discharge cylinder, and the diameter sizes of the first sieve distribution port, the second sieve distribution port and the third sieve distribution port may be different.

Preferably, the first sub-sieve opening, the second sub-sieve opening and the third sub-sieve opening are circular holes or strip-shaped holes.

Preferably, the material distribution opening is used for screening and discharging ores with the diameter size of 10mm-50mm, and the material discharge opening is used for discharging ores with the diameter size of 50mm-500 mm.

Drawings

Fig. 1 is a schematic perspective view of the ore washing apparatus of the present invention.

Fig. 2 is a side view of the ore washing apparatus of the present invention.

Fig. 3 is a top view of the ore washing apparatus of the present invention.

Fig. 4 is a sectional view taken along a-a in fig. 3.

Detailed Description

In order to explain technical contents and structural features of the present invention in detail, the following description is made with reference to the embodiments and the accompanying drawings.

Referring to fig. 1 to 4, the present invention provides an ore washing apparatus 100 suitable for cleaning and screening ores. The ore washing device 100 provided by the preferred embodiment of the utility model comprises a mounting plate 10, a cleaning barrel 20 rotatably installed on the mounting plate 10, and a driving mechanism 30 installed on the mounting plate 10 and connected with the cleaning barrel 20, wherein the cleaning barrel 20 comprises a feeding barrel 21, a cleaning barrel 22 and a discharging barrel 23 which are sequentially communicated along the longitudinal direction of the cleaning barrel, the feeding barrel 21 is provided with a feeding hole 211 for receiving ores and cleaning liquid, the cleaning barrel 22 has a certain length, a plurality of discharge openings 221 are uniformly distributed on the circumference of the opposite rear end of the cleaning barrel 22, the cleaning liquid and silt are discharged from the discharge openings 221, the discharging barrel 23 comprises a plurality of discharge openings 231 uniformly distributed on the barrel wall of the opposite rear end of the discharging barrel and a discharge hole 232 arranged at the end of the discharging barrel, the mounting plate 10 or the cleaning barrel 20 on the mounting plate 10 is obliquely arranged, so that the feeding hole 211 is higher than the discharge openings 231 and the discharge openings 232, the driving mechanism 30 can drive the cleaning barrel 20 to rotate, so that the ore to be cleaned rolls from the feeding port 211 to the direction of the material separating port 231 and the discharging port 232, and is repeatedly washed by the cleaning solution in the rolling process, the ore with relatively small diameter size after being cleaned is discharged from the material separating port 231, and the ore with relatively large diameter size is discharged from the discharging port 232. The inclination angle of the mounting plate 10 relative to the horizontal plane is 5-6 degrees when the mounting plate is mounted, or the inclination angle of the cleaning cylinder 20 relative to the mounting plate 10 when the cleaning cylinder is mounted on the mounting plate 10 is 5-6 degrees, and the cleaning liquid used in the application is specifically industrial water.

With reference to fig. 2 and 4, specifically, in this embodiment, a plurality of first blades 24 are uniformly distributed on the inner peripheral wall of the feeding cylinder 21, and the plurality of first blades 24 are spirally arranged to form a centrifugal force, so that the ore entering the feeding cylinder 21 is tumbled and thrown into the cleaning cylinder 22, thereby the cleaning effect is better, the ore to be cleaned is not stacked in the feeding cylinder 21, and the feeding is better and smoother. The inner peripheral wall of the cleaning cylinder 22 is provided with a plurality of second blades 25 arranged at intervals, so that the cleaning effect is further improved, and the ore accumulation is prevented. A plurality of second blades 25 arranged at intervals are also arranged on the inner peripheral wall of the opposite front end of the discharging cylinder 23, so that the screening efficiency and effect can be improved. The first blade 24 is a spiral blade, and the second blade 25 is a straight blade or an inclined blade.

Referring to fig. 1, 3 and 4, in the present embodiment, the cleaning cylinder 22 includes three cleaning sections 22a and a water leakage section 22b, which are sequentially connected, and the drain opening 221 is disposed in the water leakage section 22 b. The discharging cylinder 23 comprises a receiving section 23a and a screening section 23b which are communicated, the receiving section 23a is used for being communicated with the cleaning cylinder 22, and the distributing port 231 and the discharging port 232 are correspondingly arranged at the cylinder wall and the end of the screening section 23 b. Wherein, the cleaning section 22a of the relative front end of the cleaning cylinder 22 is communicated with the output end of the feeding cylinder 21, and the water leakage section 22b of the relative rear end of the cleaning cylinder 22 is communicated with the receiving section 23a of the discharging cylinder 23. More specifically, a plurality of second blades 25 are uniformly distributed on each inner peripheral wall of the three cleaning sections 22a of the cleaning cylinder 22, and the second blades 25 between the three cleaning sections 22a are arranged in a staggered manner, so that the second blades 25 arranged in the cleaning section 22a at the opposite front end of the cleaning cylinder 22 and the first blades 24 in the feeding cylinder 21 can be butted in a one-to-one correspondence manner, the ore turning effect is better, and the cleaning effect is further improved.

Referring to fig. 1 to 4, in the embodiment, the driving mechanism 30 includes a driving motor 31, a gear 32 connected to an output end of the driving motor 31, and a gear ring 33 protruding on an outer peripheral wall of the cleaning cylinder 20, the gear ring 33 is engaged with the gear 32, and the driving motor 31 can drive the gear 32 to rotate, so that the gear ring 33 drives the cleaning cylinder 20 to rotate. The driving motor 31 is installed at the opposite center of the mounting plate 10, the toothed ring 33 is detachably installed at the opposite center of the cleaning cylinder 20, and the feeding port 211 of the feeding cylinder 21, the material distributing port 231 and the material discharging port 232 of the discharging cylinder 23 are suspended at the front and rear opposite ends of the mounting plate 10. Of course, in other embodiments, the number of the driving motors 31, the gears 32 and the gear rings 33 arranged in a one-to-one correspondence may also be 2 or 3, so as to meet the requirements of different capacities.

Referring to fig. 1 to 4, in the present embodiment, specifically, the ore washing device 100 of the present invention further includes at least two supporting assemblies 40 disposed on the mounting plate 10 in parallel and spaced apart, each supporting assembly 40 includes two supporting bases 41 disposed on the mounting plate 10 symmetrically with respect to the cleaning drum 20, two rollers 42 disposed on the two supporting bases 41 in a one-to-one correspondence manner, and a roller ring 43 protruding from the outer circumferential wall of the cleaning drum 20, a guiding groove 421 corresponding to the shape of the roller ring 43 is disposed on the outer circumferential wall of the roller 42, and the roller ring 43 is rotatably mounted in the guiding groove 421 of the two rollers 42 opposite to the roller ring 43.

Preferably, the mounting plate 10 is provided with a carrying assembly 40 at each of the opposite front end, the opposite center and the opposite rear end, so that the multiple carrying assemblies 40 can provide more stable supporting force for conveniently carrying the rotating washing drum 20. When the driving mechanism 30 is installed at the relative center of the mounting plate 10, the carrying assembly 40 located at the relative center of the mounting plate 10 and the driving mechanism 30 are arranged in a staggered manner, so that the two components act separately without interfering with each other, the structure of the whole device is more compact, and the layout is more reasonable. Specifically, the rollers 42 in each carrying assembly 40 can be arranged at the same height, and when in use, the mounting plate 10 is only required to be arranged obliquely, and the cleaning cylinder 20 is arranged obliquely therewith, so that the height of the feeding port 211 can be higher than the height of the material distributing port 231 and the material discharging port 232; or, the supporting heights of the rollers 42 of at least two supporting assemblies 40 are sequentially reduced from front to back, so that the cleaning cylinders 20 supported on the supporting assemblies 40 are obliquely arranged on the mounting plate 10, and the height of the feeding port 211 is larger than the heights of the material distribution port 231 and the material distribution port 232, thereby facilitating cleaning and material distribution.

Referring to fig. 1, fig. 3 and fig. 4, specifically, in the present embodiment, the material dividing port 231 includes a first material dividing port 2311, a second material dividing port 2312 and a third material dividing port 2313 sequentially arranged along the longitudinal direction of the discharging cylinder 23, the number of the first material dividing port 2311, the number of the second material dividing port 2312 and the number of the third material dividing port 2313 are all plural, and the plural first material dividing ports 2311, the plural second material dividing ports 2312 and the plural third material dividing ports 2313 are respectively and uniformly arranged in the circumferential direction of the cylinder wall of the discharging cylinder 23, and the diameter sizes of the first material dividing port 2311, the second material dividing port 2312 and the third material dividing port 2313 may be different to correspond to ores with different diameter sizes, thereby realizing the screening and the collection of ores with different diameter sizes, and effectively improving the screening efficiency. The first sub-sieve port 2311, the second sub-sieve port 2312 and the third sub-sieve port 2313 are circular holes or strip-shaped holes. In other embodiments, when the first sifting port 2311, the second sifting port 2312 and the third sifting port 2313 have the same diameter size, the sifting of the ore within the same diameter size range is correspondingly completed.

In general, the material separating port 231 is used for screening and discharging ores with the diameter size of 10mm-50mm, and the material discharging port 232 is used for discharging ores with the diameter size of 50mm-500 mm. Specifically, the first sifting port 2311 is used for sifting and discharging small-particle ore with a diameter size of less than 10mm, the second sifting port 2312 is used for sifting and discharging ore with a diameter size of 10mm to 30mm and relatively larger particles, and the third sifting port 231 is used for sifting and discharging ore with a diameter size of 30mm to 50mm and relatively larger particles.

Referring to fig. 1 to 4, the operation of the ore washing apparatus 100 of the present invention will be further described:

when the device is used, the mounting plate 10 is obliquely mounted on a rack or other bearing objects, the driving mechanism 30 drives the cleaning barrel 20 to rotate, after the ore to be cleaned and the industrial water for cleaning the ore enter the rotating cleaning barrel 20 from the feeding hole 211 of the feeding barrel 21, the ore continuously rolls in the direction of the discharging hole 232 in the cleaning barrel 20 under the action of self gravity and the rotating force of the cleaning barrel 20, so that the ore passes through the cleaning barrel 22 with a certain length and is comprehensively washed in the rolling process, the industrial water with silt after cleaning is discharged from the discharging hole 221 at the relative rear end of the cleaning barrel 22, most of residual water attached to the surface of the cleaned ore is thrown off to be discharged from the discharging hole 221 in the rotating process, and finally, the cleaned and primarily dewatered ore is screened and discharged from the material distributing hole 231 and the discharging hole 232 of the discharging barrel 23, the ore with relatively small diameter size is screened and discharged by the material distributing opening 231, while the ore with relatively large diameter size is screened and discharged by the material discharging opening 232, so that the automatic flow operation of cleaning and screening the ore is realized.

Compared with the prior art, the cleaning cylinder 20 of the ore washing device 100 provided by the utility model comprises a feeding cylinder 21, a cleaning cylinder 22 and a discharging cylinder 23 which are sequentially communicated, cleaning liquid for ores to be cleaned and cleaning ores enters the cleaning cylinder 20 from a feeding hole 211 of the feeding cylinder 21, the cleaning liquid passes through a cleaning cylinder 22 with a certain length and is discharged from a material distributing hole 231 and a material discharging hole 232 of the discharging cylinder 23, and the cleaning cylinder 20 is obliquely arranged on the mounting plate 10 or the mounting plate 10, so that the feeding hole 211 is higher than the material distributing hole 231 and the material discharging hole 232, when the cleaning cylinder 20 rotates under the driving of the driving mechanism 30, the ores roll in the direction from the feeding hole 211 to the material discharging hole 232 in the cleaning cylinder 20 under the action of self gravity and the rotating force of the cleaning cylinder 20, thereby realizing the complete cleaning in the rolling process and having better cleaning effect; the cleaning liquid and the silt after cleaning are discharged from a plurality of discharge openings 221 uniformly distributed in the circumferential direction of the opposite rear end of the cleaning cylinder 22, and most of the cleaning liquid attached to the surface of the cleaned ore is thrown off to be discharged from the discharge openings 221 in the rotating process, so that the liquid and the silt are fast in discharge speed, and the silt is discharged at the position relatively far away from the

discharge openings

231 and 232 by combining the material distribution openings 231 and the discharge openings 232 arranged at the opposite rear end of the discharge cylinder 23, so that the finally discharged ore is cleaner; in addition, the plurality of material distributing openings 231 are uniformly distributed on the cylinder wall of the material discharging cylinder 23, the material discharging openings 232 are formed in the end portion of the material discharging cylinder 23, so that ores with relatively small diameter sizes after being cleaned can be screened and discharged through the material distributing openings 231, and ores with relatively large diameter sizes are discharged through the material discharging openings 232, and accordingly primary screening of the ores is achieved.

The above disclosure is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the utility model, so that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the utility model.

Claims

1. An ore washing device is characterized by comprising a mounting plate, a cleaning barrel which is rotatably arranged on the mounting plate, and a driving mechanism which is arranged on the mounting plate and connected with the cleaning barrel, wherein the cleaning barrel comprises a feeding barrel, a cleaning barrel and a discharging barrel which are sequentially communicated along the longitudinal direction of the cleaning barrel, the feeding barrel is provided with a feeding hole for receiving ore and cleaning liquid, the cleaning barrel is provided with a certain length, a plurality of discharge openings are uniformly distributed in the circumferential direction of the cleaning barrel relative to the rear end of the cleaning barrel, the cleaning liquid and silt are discharged from the discharge openings, the discharging barrel comprises a plurality of material distributing openings uniformly distributed on the barrel wall of the rear end of the cleaning barrel and a discharge opening arranged at the end part of the discharging barrel, the cleaning barrel on the mounting plate or the mounting plate is obliquely arranged, so that the feeding hole is higher than the material distributing openings and the discharge opening, and the driving mechanism can drive the cleaning barrel to rotate, so treat abluent ore by the feed inlet towards divide the material mouthful to reach the direction of discharge gate rolls, and washes repeatedly through the washing liquid at the in-process that rolls, washs back diameter size ore that is little relatively by divide the material mouthful ejection of compact, diameter size ore that is big relatively by the discharge gate ejection of compact.

2. The ore washing device according to claim 1, wherein a plurality of first blades are uniformly distributed on the inner circumferential wall of the feeding cylinder, the plurality of first blades are spirally arranged to form a centrifugal force, and a plurality of second blades are arranged at intervals on the inner circumferential wall of the cleaning cylinder and the inner circumferential wall of the opposite front end of the discharging cylinder respectively.

3. The ore washing device according to claim 1, wherein the cleaning cylinder comprises three cleaning sections and a water leakage section which are communicated in sequence, and the drain opening is arranged on the water leakage section.

4. The ore washing device according to claim 1, wherein the discharge barrel comprises a receiving section and a screening section which are communicated with each other, the receiving section is communicated with the cleaning barrel, and the material dividing port and the discharge port are correspondingly arranged on the barrel wall and the end part of the screening section.

5. The ore washing device according to claim 1, wherein the driving mechanism comprises a driving motor, a gear connected to an output end of the driving motor, and a toothed ring protruding from an outer peripheral wall of the washing drum, the toothed ring is engaged with the gear, and the driving motor can drive the gear to rotate, so that the toothed ring drives the washing drum to rotate along with the toothed ring.

6. The ore washing device of claim 1, further comprising at least two supporting assemblies arranged on the mounting plate in parallel and at intervals, wherein each supporting assembly comprises two supporting seats symmetrically arranged on the mounting plate by taking the cleaning drum as a center, two rollers arranged on the two supporting seats in a one-to-one correspondence manner, and a roller ring protruding on the peripheral wall of the cleaning drum, the peripheral wall of each roller is provided with a guide groove corresponding to the shape of the roller ring, and the roller ring is rotatably erected in the guide grooves of the two rollers opposite to the roller ring.

7. A mineral washing apparatus according to claim 6, wherein the drive mechanism is located at the opposite centre of the mounting plate, the opposite front, centre and rear ends of the mounting plate each being provided with a said carriage assembly, and the carriage assemblies at the opposite centre of the mounting plate are arranged offset from the drive mechanism.

8. The ore washing device according to claim 1, wherein the material dividing port includes a first screen dividing port, a second screen dividing port and a third screen dividing port sequentially arranged along a longitudinal direction of the discharging cylinder, the number of the first screen dividing port, the second screen dividing port and the third screen dividing port is plural, the plural first screen dividing ports, the plural second screen dividing ports and the plural third screen dividing ports are respectively and uniformly arranged in a circumferential direction of the cylinder wall of the discharging cylinder, and the diameter sizes of the first screen dividing port, the second screen dividing port and the third screen dividing port may be different.

9. The ore washing apparatus of claim 8, wherein the first, second and third sub-screen openings are circular or strip-shaped openings.

10. The ore washing device according to claim 1, characterized in that the material dividing opening is used for screening and discharging ore with the diameter size of 10mm-50mm, and the material discharging opening is used for discharging ore with the diameter size of 50mm-500 mm.