Payment & Shipping Terms:
|Product Name:||Rod Mill||Motor Type:||AC Motor|
|Weight:||20-175 T||Warranty:||1 YEAR|
|Effective Volume:||4.6~60.7m3||Coal Water Slurry Rod Mills:||3.2x4.5~4.0x6.7m|
|Max .Effective Volume:||77.6m3||Port:||QingDao,TianJin,ShangHai|
150T/H Ore Grinding Mill,
77.6m3 Ore Grinding Mill,
77.6m3 quartz sand grinding mill
Rod mills are very similar to ball mills, except they use long rods for grinding media. The rods grind the ore by tumbling within the the mill, similar to the grinding balls in a ball mill. To prevent the conditions leading to rod charge tangling, the length to diameter ratio is maintained at 1.4 to 1.6. Rod mills accept feed up to about 50 mm (2 in.) and produce a product in the size range of 3000 to 270 mm (–4 to –35 mesh). Grinding action is by line contact between the rods extending the length of the mill. Rods tumble and spin in roughly parallel alignment simulating a series of roll crushers. This results in preferential grinding of coarse material and minimizes production of slimes.
Of the three main types of rod mill, overflow, end peripheral discharge, and center peripheral discharge only the overflow mill is in common usage. Wet grinding rod mills are normally used in the mineral processing industry. Dry grinding is used in some areas; however, it is confronted with problems and should be avoided except where absolutely necessary. Rod mills operate at lower speed than ball mills since the rods are rolled and not cascaded. For an equivalent grind, a rod mill uses less steel than a ball mill because of the lower speed and better contact between the media and ore. The rod charge must be maintained in good working condition, and broken and worn rods must be removed. Rod mills usually require greater operator attention. It is important that the rods stay essentially parallel to one another. If rods become misaligned, grinding action is lost and, more importantly, rod tangles occur. Maximum rod length is limited to about 6.1 m (20 ft). This in turn limits the length, diameter, and capacity of rod mills. The heavier rods acting upon the lifters and liners result in greater wear on the mill liners.
Rod mills normally carry 35 to 65% rod charge by volume. The limits on charge level are (1) keeping the feed end trunnion open so that feed will get into the mill, and (2) keeping the rod charge low so rods will not work their way into discharge openings where they can cause rod tangling.
Rod mills Applications
The rod mill, a tumbling mill characterized by the use of rods as grinding media, is used for grinding ores, coal/coke, and other materials for both wet
and dry applications. The rod mill performs best when making products having a top size of 4 mesh to 16 mesh operating in open circuit, or as fine as 35 mesh operating in closed circuit with a screen or other sizing device. The rod mill accepts feed ore as coarse as 1 1/2” top size although better performance is obtained by restricting ore feed size to 3/4”.
Materials too wet for fine crushing and dry screening may be wet ground in a rod mill. Practice has demonstrated the ability of a rod mill to dry grind damp materials that will pack or plug other grinding equipment. and scrap loss are reduced by correct selection of liners for the specific grinding duty. Additional
benefit results from use of a backing material, such as rubber between the liners and the mill shell.
The cylindrical mill adopts the driving type edge-driving, center-driving, edge-driving with multi-point meshing, etc; driven by asynchronous motor +reducer +pinion and gear as well as synchronous motor + air lclutch + pinion and gear.
Generally supported by static-dynamic pressure bearing on both ends. Fuuly closed self-aligning 120º osculation rocker bearing is used. Also single or double slipper staic- dynamic bearings can be used. The bush is made by NC machine.
The large open gear is designed using AGMA standard, Equipped with reliably sealed gear housing and grease ahtomatic spraying lubrication system.
The shell is key part of a mill. Carry out finite element analysis on it with computer to ensure the reliable operation;
The shell is automatically welded, ultrasonic inspected, wholly annealed and machined by large special machine tools on one chucking; there special seal on static-dynamic connection parts , ch as feed and discharge hoper, trunnion, etc, to prevent oil and slurry leakage;
The liner is of wear-resistance material mad by our company, wich has been specially heat-treated, with high hardness and long service life. Also other wear-resistance casting or rubber liner can be used;
There are slow speed drive for medium and large mill;
The high and low pressure lubricating station is equipped for medium and large mill;
The control and protection system is controlled by PLC.
Historically, rod mills have been used as the first grinding stage after crushing in mineral benefici ation circuits. The rod mill product was further ground in ball mills before separation of valuable minerals from the host rock. With the advent of semi-autogenous (SAG) mills replacing secondary and tertiary crushing as well as first stage grinding,the rod mill has fallen out of favor for new large mineral beneficiation circuits.
A recent application for a trunnion overflow rod mill is in the preparation of coal and petroleum coke slurries for Integrated Gasification Combined Cycle electric power generation and co-generation
facilities. The relatively coarse open circuit rod mill product, plus the ability to not generate excess fines, is key to making a high percent solids, low viscosity slurry capable of being pumped directly into the gasification reactor vessel. This service has been proven to be an excellent application for the traditional design rod mill.
End peripheral discharge rod mills are used most frequently for dry grinding operations. Grinding damp materials to moderately coarse products in open circuit is feasible by using hot air, inert gas,or combustion gases to air-sweep the rod mill.A recent new application for the end peripheral discharge rod mills has been the preparation of fuel for Circulating Bed Boilers (CFB). It is critical to have a coarse product with the fewest amount
of fines for this product as the fuel mass must be fluidized by combustion airflow. This same airflow will elutriate excess fines from the fuel mass be-fore combustion is complete and reduce boiler efficiency through loss of the fuel fines with the ash.
Rod Mill Main Technical Parameters:
|Load of grinding media (t)||Electromotor||Size
Contact Person: sales