ball mill drive reduction in norway

Ball mills are usually designed with a maximum reduction factorratio of 601 although it is possible to achieve reduction ratios of up to 701 The electric drive for a ball mill should be able to handle loads where the ball mill is charged by up to 45 with balls

Ball milling is a size reduction technique that uses media in a rotating cylindrical chamber to mill materials to a fine powder As the chamber rotates the media is lifted up on the rising side and then cascades down from near the top of the chamber

Ball mills tumble iron or steel balls with the ore The balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds The feed to ball mills dry basis is typically 75 vol ore and 25 steel The ball mill is operated in closed circuit with a particlesize measurement device and sizecontrol cyclones

These large coal crushing drive systems are usually rotated by motordriven gearing A typical application consists of a motordriven primary singlestage reducer that through a flexible coupling drives a large open pinion which in turn meshes with a large ball mill ring girth gear that is attached directly to the ball mill

Ball Mills Steel Ball Mills Lined Ball Mills Particle size reduction of materials in a ball mill with the presence of metallic balls or other media dates back to the late 1800’s The basic construction of a ball mill is a cylindrical container with journals at its axis

A ball mill also known as pebble mill or tumbling mill is a milling machine that consists of a hallow cylinder containing balls mounted on a metallic frame such that it can be rotated along its longitudinal axis The balls which could be of different diameter occupy 30 – 50 of the mill volume and its size depends on the feed and mill size

Sep 29 2015 · The present work aims at exploring the size reduction of γAl 2 O 3 using three mill types single ball mill air jet mill and planetary ball mill In a similar manner to previous studies Zhou and Snyder 1991 Knozinger and Ratnasamy 1978 Xray diffraction XRD and Transmission Electron Microscopy TEM have been used to characterise

In general ball mills can be operated either wet or dry and are capable of producing products on the order of 100 pm This duty represents reduction ratios as great as 100 The ball mill an intermediate and finegrinding device is a tumbling drum with a 40 to 50 filling of balls usually steel or steel alloys

Nov 30 2015 · PRINCIPLE A ball mill works on the principle of impact and attrition size reduction is done by impact as the balls drop from near the top of the shell 7 CONSTRUCTION Wet or dry ball mill grinding machine consists of following parts 1 Feeding part 2 Discharging part 3 Turning and driving part gear motor etc 4 Rotating balls 8

The basic parameters used in ball mill design power calculations rod mill or any tumbling mill sizing are material to be ground characteristics Bond Work Index bulk density specific density desired mill tonnage capacity DTPH operating solids or pulp density feed size as F80 and maximum ‘chunk size’ product size as P80 and maximum and finally the type of circuit openclosed