Dry Grinding Ball Mill

Ball millOperating instructionI. General Introduction for Ball Mill1. Structure:1. Feeder; 2. Feeding unit; 3. Discharging unit; 4. Cylinder;5. Girth gear; 6.Rack; 7. Transmission Division; 8. Bearing DivisionFig I Diagram of Ball MillAs shown in Fig I, the ball mill generally consists of eight parts: feeder, main bearing, feeding unit, cylinder, discharging unit, gear mechanism, gear cover, and foundation.As per the types of ball mills, they can be classified into overflow type (MQY type) and trellis type (MQG type).As per driving types of ball mills, they can be classified into dextrorotary type and laevorotatory type.As per modes of installing ball mills, they can be classified into with base plate type and without base plate type. With regards to ball mill with base plate, except an additional base plate, all the other parts are the same as those of ball mill without base plate. Below 15 series is with base plate.As per motor modes of ball mills, they can be classified into YR motor and JR motor. The structure difference between two types is the motor, the parts march to the motor and basement. The principle of two type marched is: to adopt YR motor when smaller than 80KW, to adopt JR motor when larger than 80KW.II. Installation of Ball Mill:1. Foundation of Ball Mill:① The foundation of ball mill is made of reinforced concrete. The foundation shall be solid and firm, and shall not sink. In case of slight sinkage, make sure to ensure consistent sinkage of each part of the foundation. Otherwise, it may exert negative effect upon normal working and operation of the ball mill.② Only relevant dimensions that can ensure correct installation of the ball mill are listed on the ball mill foundation drawing provided by us. The materials, structural design and peripheral dimensions of the foundation shall be determined according to geologic condition and other actual conditions of the user's installation site.2. General Precautions for Installation:① Before installation, check whether the foundation meets the requirements. Hole pitch of each anchor bolt on the foundation and permissible error of height mark of the foundation shall be in conformity with Table 1.Table 1  Hole pitch of each anchor bolt on the foundationand permissible error of height markHole Pitch L orHeight Mark H (㎜)Permissible Error (㎜)Dimensional deviation of relative position between height marks (㎜)≤500±11＞500～1000±1.51.5≥1000±22② Check the quantity of the parts and components; check whether they are provided completely.③ Before installation, clean the surface of the parts and components, remove the burrs, rustings, foreign matters and oil stain.④ During installation, protect each coupling and fitting surface properly, apply clean lubricating oil onto each sliding matching surface, and apply clean lubricating grease to each fixed coupling surface. 3. Main parameter of the Ball Mill:  Table 2modelCylinder diameterCylinder lengthRotary speedMotor modelMotor powerMotor speedEffective volumeMaximum load of ball090990090037.1Y180L-615KW9700.911.50918900180037.1Y200L-815KW7400.911.512281200280029.5YR280S-855KW7252.8515301500300029.8JR117-880KW72551021302100300024.05JR136-8180KW7359.01821362100360024JR137-8210KW7351121.621402100400024JR138-8245KW73512.123.524362400360022.5JR138-8A280KW743142624402400400022.5JR138-8B320KW743152624422400420022.5JR500L2-8355KW745162624452400450022.5JR500L3-8380KW7451729.527362700360021.6JR500L3-8380KW74519.436  4. Installation of the Ball Mill:A. Installation of rotating part: The parts such as feeder, charging unit, cylinder, girth gear, discharging unit and main bearing of the ball mill have been assembled prior to delivery, which constituting the rotating part of ball mill.① Put the lower part of gear cover at corresponding position on the foundation.② Put the anchor bolt of main bearing block into corresponding ground hole, unbolt the nut and gasket, etc. Put four groups of adjusting blocking iron onto the position of bed plate of each bearing block. While putting, make each group of blocking iron approach the hole of anchor bolt as close as possible and four groups of blocking iron be arranged as symmetrically as possible.③ Adjust the positions of bearing block and bed plate of bearing block.Loosened the Bolt before the bearing block and the bearing bed plate, adjust the adjustable bolts and nuts at both sides of bed plate of bearing block, to make longitudinal center of bed plate of bearing block coincide with the center of bearing block as much as possible.④ Lift the rotating part (please note: the casting lifting rings on charging and discharging end caps at both ends of ball mill shall be only used for lifting the end caps, and shall not be used for lifting the rotating part) and descend it gradually after spotting its location, to make axial diameter at both ends fall onto the corresponding Sizing Block. During the whereabouts of T-Anchor Bolt should be the lower part of the first card into the corresponding slots in Leong.⑤ Adjust radial position of bed plate of bearing:After the rotating part is lifted onto corresponding position, ensure that permissible error of parallelism between the center connection of bed plate of bearing block at both ends of ball mill and the ball mill center line lined out on the foundation ≤0.5/1000㎜ (designed on the basis of centers of two main bearings). Method of checking and adjusting: line out perpendicular line at the center of longitudinal end face of two bearing blocks, measure the distance between perpendicular line and center line of ball mill lined out on the foundation; in case of exceeding permissible error, lift the rotating part and re-install it.⑥  Adjust center height, radial and axial level and bearing block:After the bed plate of bearing block of rotating part is placed onto the foundation, find out correct center height of bearing block, radial and axial levels of bearing block synchronically and make them meet the following requirements:Permissible error of center height of bearing block ≤±4㎜; permissible error of levelness of bed plate of each bearing block ≤0.1/1000㎜. Measuring method: measure the levelness by placing the level meter in axial and radial directions at corresponding positions of bed plate of bearing block and the bearing.Permissible error of levelness of connection by axle center for two bearing blocks ≤0.2/1000㎜ (calculated on the basis of two bearing centers). Ensure that the discharging end is lower.⑦ After the position and level of both bearing block and bed plate of bearing block is adjusted and set properly, tighten the connecting bolts between bearing block and bed plate of bearing, and tighten the adjustable bolts and anchor bolts of bed plate of bearing block. And then, re-check the levelness at each position with the aforesaid method. In case of exceeding permissible error, loosen the anchor bolts and re-adjust them until the levelness at each position meets the requirements after tightening the anchor bolts.B. Installation of driving unitInstallation of this part includes installing such parts as pinion seat, reducer, motor, couplings, and gear cover, etc.① Put the anchor bolts of pinion seat, reducer and motor into corresponding holes on the foundation, and take off their nuts and gaskets. Place four groups of adjusting blocking iron on respective locating position of pinion seat, reducer and motor. While placing them, make each group of blocking iron approach the hole of anchor bolt as close as possible, and four groups of blocking iron be arranged as symmetrically as possible.② Cover high-speed and low-speed shaft ends of the reducer with high-speed and low-speed coupling casing. Put the pinion seat and the reducer and motor with base plate onto their positions respectively. And pull the anchor bolts through corresponding holes, and mount the gaskets and nuts.③ Adjust the positions and levels of pinion seat, reducer and motor synchronically, with the result of adjustment meet the following requirements:a. Permissible error of levelness of pinion shaft ≤0.1/1000㎜. And the deviation direction is consistent with the deviation direction of rotating part. Permissible error of parallelism between axial line of pinion and girth gear ≤0.1/1000㎜. Contact area when bull gear engages with the pinion ≥ 40% of tooth depth, ≥50% of face-width. In order to achieve the above mentioned requirements for engagement of pinion and girth gear, re-adjust the position of axial line of rotating part, if necessary. The gear backlash of bull gear engages with the pinion should meet the requirement of table 3.Table 3  Gear backlash of bull gear engages with the pinion Cylinder diameter（mm）Length of cylinder（mm）Gear backlash（mm）φ90018000.84~1.2φ120016002800φ150020000.84~1.230003500φ210024000.84~1.3300036004000φ240036000.84～1.4240004200φ270036000.84～1.424000 b. Permissible error of levelness of reducer and motor ≤0.1/1000㎜.Permissible error of coaxiality between pinion shaft and low-speed shaft of reducer ≤φ0.3.Permissible error of coaxiality between motor shaft and reducer shaft ≤0.3.④ After adjusting and leveling the position and level of each component of the driving unit properly, assemble the coupling of each component correctly.⑤ Assembling of gear cover:a. Adjustment before installing gear cover:For the deformed gear covers during transportation, shaping should be conducted prior to assembling, to meet requirements. Resetting of the sealing felt strip along the pinion shaft of gear cover, to make it available with a reliable sealing to pinion shaft after assembling.b. Assembling of gear cover:Foreign objects and oil on the bull gear and pinion before assembling of gear cover should be well cleaned before locating the lower-cover of gear as required. Check the assembling clearances and sealing clearances at each spot to ensure that sealings are in good conditions as required before fixing the upper cover of gear. Check now the assembling clearance and sealing condition of gear cover at each spot to ensure full compliance. In case of complete compliance, tighten all the bolts of gear cover.c. Grouting of anchor bolt holes of foundation and tightening of anchor bolts:After installation and adjustment of all the above parts, grouting of sandstone and concrete grout can be conducted into each anchor bolt hole as required. Please note that for anchor bolt holes of main bearing seat without ground beam and pinion seat, to ensure a grouting till bottom for ground beam, check again the installation requirements at each place as per instructions above after concrete mortar in each anchor bolt hole is fully dried. If any change or unconformity is found, make further micro adjustment till installation at each place reach requirements and then tighten each anchor bolts at each spot to finish the installation.5. Precautions for Installation of Each Part of Ball Mill:① Lead paint should be applied between end cover of loading/unloading and drum flange face when making assembling. However, spacer is prohibited.②Rolling bearing inner ring and feeding cover journal and discharging journal cover for light Journal cover fit (P7 with) the application of heat bearing assembly installed law. When the bearing assembly can be placed in the oil, with oil heated to about<100℃  and then removed bearings while it is hot, set in the Journal. After cooling bearings, bearings installed in the building before rolling bearings should be applied within the proper calcium-based grease.③Before and after the installation of the two bearings, shall be guaranteed the top hole and the hole cup oil tank top unimpeded, to ensure that the ball mill can be used in continuous rolling bearing oiling④Connection of end cover of loading/unloading with each drum flange is the same as that of girth gear with each drum flange, i.e. all the bolts of a couple of connecting flange receive concentric drilling, with three reamed bolts equispaced circumferentially. Therefore, in the event of disconnecting the connection between them, make markings of assembling positions before disconnecting, to facilitate future assembling.⑤The cast flying-rings on the loading/unloading end cover shall only be used for purpose of lifting end covers, and shall not be used for lifting the well-assembled end covers and drums.6. Casting rings on the feed or discharge cover is only for use when lifting cover, you can not make it used in lifting cover assembled and the cylinder.specfication itemsφ1200× 1600 φ1500×2000 φ1500×2400φ2400×3600φ2700×360030003000400018003500360042004000Face runout（㎜）≤0.7≤0.8≤0.9≤1.0≤1.0Radial runout of tooth ring(㎜)≤0.9≤1≤1Table 4 Permissible error of heavy gear ring surface and tooth ring radial runout Ⅳ.  Test-Run of Ball Mill1. Preparation before test run① Check dryness and insulation of electric car and also no-load running.② Check carefully the fasteners at each spot to see if there is any loosening.③ Lubrication of each oil site:A. See Table 6 for the lubricant and lubricating methods for each oil site of ball millTable 6  Lubricant and lubricating methods for each oil site of ball millOil siteMain bearing andpinion bearingReducerOpen type bull gearLubricant types & lubricating methodsLithium base grease, manual charging grease into oil-cup intermittentlyFill gear oil tank at one go for continuous lubricationManual charging lithium base grease intermittently for lubricationB. The points below shall be followed besides filling lubricating grease for ball mill and each oil site as required in Table 6:① Lubricating grease in each bearing oil-cup should be filled till oil circuit is full.② For reducer, its oil groove (sump) should have its grease level between 0.7~1 gear of the bottom gear .③ For gear pair of drum lubricated with grease, apply moderate lubricating grease between each tooth of bull gear.④ Check if the sealing device at each sealing spot complies with requirements.⑤ Check if each safety device is complete and reliable.⑥  Conduct no-load (no balls added or no feeding) barring. Check if each rotating part of ball mill is blocked or there is any abnormal sound.2. No-Load Test-Run:After approved through no-load barring of ball mill, no-load test-run can be conducted, which shall meet the following requirements:① Lubrication of all oil sites are normal without any leaking.② Heating with main bearing≤40℃③ Stable running of ball mill without any abnormality.④ No loosening with lining board and any driving parts.⑤ No significant change with power consumption for ball mill, with no abnormal occurrence for continuous running over 8hours.3. Loaded Test-RunLoaded test-run can be conducted after approved through no-load test-run of ball mill, which shall meet the following requirements:① 20～30％ of the required load of balls and materials shall be loaded into ball mill prior to running, and add 10％ of the load every 30 minutes after running for 8～10 hours and approved normal, until continuous running of 10～20hours under normal feeding, after reaching the full load.② Stable running of ball mill without any intense and periodic beats, or impact sound.③ Current and temperature rise of motor are within permissible range.④ Normal lubrication at each lubricating point, with temperature rise of main bearing≤40℃.⑤ No leakage of water, mortar or oil with each seal spot.⑥  Check if there is any loosening with all fasteners.Ⅴ  Operation, Service and Maintenance of Ball Mill1. Operation of ball mill:① Startup of ball millA. Check if all connecting bolts are tightened before startup of ball mill, and if there is any loosening with all connected parts.B. Check if lubrication of oil site meet requirements.C. Check if there is anything around ball mill and sorting machine, which may prevent the machines from running.D. Startup sequence for devices of loop; start ball mill before sorting machine, followed by ore feeding after normal running.② Stop of grinding loop:If grinding loop stops running, stop ore feeder first. Then stop ball mill after the ores are processed inside the drum of ball mill. Take out the screw axis of the sorting machine out of the sand surface. Stop the sorting machine finally.2. Service and maintenance of ball mill① Service of ball millA. Grease filling cycle of each oil site:Once per shift for main bearing and pinion bearing.For bull gear lubricated with lubricating grease, apply grease once between each tooth of bull gear for each shift.Add whenever there is shortage of grease with reducer's grease tank.B. Check periodically the bolts of lining board and elsewhere. Repair immediately in case of anything abnormal.② Maintenance of ball millPlanned maintenance is required to ensure safe running and long service-life of ball mill.A. Minor maintenance: once a month, including emergent accident handling, mainly referring to replacement of minor parts or adjustment, mostly replacing the wearing parts (like lining board) and setting the engagement for the drum gear.B. Medium maintenance: once a year, including cleaning and adjustment in a large scale over all parts of equipment, replacing substantial wearing parts.C. Major maintenance (overhauling): focusing on replacement and repairing of all main parts and components, like bull gear apart from the tasks as for minor and medium maintenance.③ Precautions for maintenance of millD. The axial structure of pinion and pinion shaft shall be symmetrical to increase the efficiency of mill pinion. Therefore, when one side of a pinion tooth cannot be used further during application due to wearing, dismantle the pinion shaft together with pinion from gear holder, and turn by 180°before re-installation. This will enable the use of the good tooth of pinion on the other side to proceed the job.E. Causes for frequent errors and troubleshooting for ball mill, see Table 7.Table 7  Causes for frequent errors and troubleshootingErrorsCausesCounter-measuresMain bearing heating, with abnormal sound, power disconnection due to motor overload1. Poor lubricating2. Muddy sand into main bearing3. Bearing broken4. Main bearing not properly fixed5. Too much or not sufficient for ore feeding1. Add lubricating grease2.Cleaning bearing and replace grease3.Replace bearing4. Reset bearing5. Adjust ore feedMotor overload or failure when starting ball millProblem with electric partRemove problems with electric partOver-current or not stable current with motor1. Feeder loosened2. Foreign objects inside ore feed3. Not proper lubrication with main bearing4. Concentration too high with discharge material5. Unbalanced weight or not evenly worn with lining board inside drum6. Wearing of gear too much7. Error with electric circuit of motor1. Tighten feeder2. Remove foreign objects from ore feed3. Improve lubrication4. Adjust operation5. Replace lining board6. Replace /repair gear7. Remove electric errorVibration of ball mill1.Not proper engagement of gear or over worn2.Anchor bolt or bolt loosened3.Connecting bolt of bull gear loosened4.Lining board fall off1.Adjust gear-side clearance or replace2.Tighten bolt3.Tighten bolt4.Check and tighten lining boardSudden strong vibration or impact sound1.Foreign objects mixed into gear engagement clearance2.Pinion gliding3.Teeth of gear broken4.Bearing or anchor bolt loosened1. Remove foreign objects2.Adjust pinion3.Replace gear4.Tighten boltWater leaking where cover is connected with drum or lining board bolt1.Bolt connecting end cover with drum get loose2.Bolt of lining board loose, broken or sealing spacer damaged1.Tighten bolt2.Tighten or replace bolt or replace sealing spacer