To buy second-hand ball mill key concerns 
The choose and buy of second-hand ball mill buyers themselves need to take some risks, so in the choose and buy must focus on looking for some qualified manufacturers. For the product to also want to do some understanding, often appear the following ball mill where the problem can be focused on. 
A, ball mill gear or bearing vibration and noise is too big. 
1. The bearing cover or bearing screws is loose. 
2. Bearing wear nothing. 
3. The bearing installation of large amount of bad or shaft bunches of low (especially for processing precision of herringbone gear) 4. The gear wear and tear or lubricating oil dirty and lack of lubricating oil. 
5. The meshing of gear, gear radial or axial runout is too large. 
6. Big gear coupling screw loosening or counterpart screw loose. 
7. The gear machining accuracy don't meet requirement. 
Second, why ball mill gear tooth surface wear too fast? 
1. The poor lubrication 
2. The meshing clearance is too large or too small contact isn't good 
3. The quality of gear cutting out requirements (such as tooth profile, radial and axial runout, heat treatment) 4. 5. Poor material ball mill gear assembly is not reasonable 
6. Teeth into the sand 
Three, ball mill transmission shaft and the bearing coupling bolt fracture. 
1. Large and small gear meshing is not correct, when tooth wear nothing, vibration big 2. Bearing installation and cooperate with the incorrect or bolt and nut loose or too tight. 
3. The shaft, the shaft coupling concentricity, levelness deviation is too large 
4. Loose shaft fixed on the healthy and cooperate with the wrong way 
5. The ball mill load is too large 
6. Poor intensity or material 
7. Processing and manufacturing quality is bad 
Four, ball mill tooth or tooth broke 
1. The ball mill teeth into the metal objects 
2. The impact load and additional load is too large 
3. The fatigue 
4. The ball mill material 
5. Improper assembly 
6. Processing bad tooth shape is not correct 
Five, the ball mill load current increases obviously 
1. The cylinder plus the ball too much or too much ore 
2. Poor lubrication bearing 
3. Gear excessive wear or vibration 
4. The move is a message bearing level is not consistent or coupling deflection 
5. The feeding device and the big spoon head screw loose connection 
6. Lining uneven weight along the circumference 
7. Ball mill belt is loose 
8. The ore fluid concentration is too high 
9. Ball mill has additional load 
Six, ball mill is starting up or load too much 
1. Stop for a long time, cylinder body is heavy fact, damp material when starting the ball load does not fall. 
2. The ball mill rotating parts have obstacles 
3. The ball mill for ore blockage 
Seven leak slurry, ball mill cylinder 
1. The lining board (board) in the screw loose or broken, seal gasket wear 2. Ball mill liner wear 3. Cylinder connecting parts is not tight