Jul 20, 2021· The plant's enrichment scheme includes two types of grinding mills – a SAG mill (semi-self-grinding) and a BALL mill (ball grinding). The semi-self-grinding mill (SAG) is 12.192 m in diameter and 7.01 m in length. Its capacity 898 cubic meters. The operating load is 626 tons. The mill is fed 125 mm grinding balls.
The dry self-grinding machine/semi-self-grinding machine is a kind of equipment which uses the ore itself to crush and grind. The barrel has larger diameter, shorter length and larger feeding size, which can replace medium crushing, fine crushing and coarse crushing. Production Process. Generally, the amount of steel balls added from the mill is 2-3X of the effective volume of the mill, and ...
measure both ball load and pulp slurry positions inside a running mill. The main data are provided in terms of toe and shoulder angles. (Figure 6.) The pulp density is an important parameter which influences the grinding efficiency. In iron ore, for instance, a variation of …
5 m3, while the volume of the chamber between the sump approximately pipe and pump discharge and the point of measurement of slurry density is approximately 2,0 m3 . The hold-up of slurry in the mill is assumed to be 30% of the volume of the load, which in turn occupies 45% of the volume of the mill.
Jun 30, 2007· The grinding efficiency of semi autogenous milling or ball milling depends on the tumbling motion of the total charge within the mill. Utilization of this tumbling motion for efficient breakage of particles depends on the conditions inside the mill. However, any kind of monitoring device to measure ...
The MillSense system provides on-line analysis of the mill charge position and volume by directly measuring the charge's toe and shoulder angles. The volumetric charge measurement has proven to be an invaluable input for mill optimization and for decreasing disturbances caused by ore changes.
Ball Mill AG/SAG Mill min max min max DESIGN DATA diameter inside shell (m) 0.9 7.9 1.8 12.2 belly length inside liners (m) 1.5 12.2 0.5 9.6 liner thickness (mm) 51 152 51 152 diameter inside shell (ft) 3 26 6 40 belly length inside liners (ft) 5 40 1.5 31.5 liner thickness (inch) 2 6 2 6
Jul 22, 2016· A distinctly noisy or mill that rattles suggests grinding media is impacting on the liners and causing unnecessary wear and possibly damage. …
Measurement of net ball volume in a SAG or ball mill can also be done by completing a grind out and re-measuring the volume with MillMapper. These volumes are accurate to the nearest 1% and account for change in internal mill volume due to liner wear and also account for the volume taken up by the feed and discharge cone which are not accounted ...
Apr 06, 2018· Mill Steel Charge Volume Calculation We can calculate the steel charge volume of a ball or rod mill and express it as the % of the volume within the liners that is filled with grinding media While the mill is stopped, the charge volume can be gotten by measuring the diameter inside the liners and the distance from the top of the
ball mill grinding media wear rate calculation. JADE monitors the power drawn and the mill load of the ball mill such that proper charging conditions are 2.1 Excessive wear of Steel Balls (Grinding media) Equation (1) outlines this relationship between . feed rate of 300ton/hr and a media wear rate of 0.24kg/ton, after 8hours, 576kg of grinding.
mill for a 1m diameter mill and n is the number of revs per minute of the mill - Morgardshammar/Marcy equation. Mill diameter inside liners - D D = Dshell-0.15 Allowance for liners Approximate mill diameter is derived from: Power =5.*6115 DL24. 6* La= * D where a is the aspect ratio L/D derived from a regression equation on 25 manufacturers' mill
Jun 19, 2015· We can calculate the steel charge volume of a ball or rod mill and express it as the % of the volume within the liners that is filled with grinding media. While the mill is stopped, the charge volume can be gotten by measuring the diameter inside the liners and the distance from the top of the charge to the top of the mill.
The fraction of mill volume occupied by rocks, grinding media and slurry in grinding mills are dominant factors influencing AG and SAG mill power draw and grinding rate. Hence accurate mill filling measurements are needed for modelling mills. To that end, it is usually necessary to enter the confined space of a grinding mill, a task that involves a degree of safety risk and a potentially ...
Sep 20, 2018· SAG mills contain a combination of mineral and a number of steel balls which together with the water can take up to 33% of the mill's effective volume (where the grinding occurs), while the balls take up 15% of the mill volume. A mill with very little load is associated with a loss of material at discharge and a useless wear of the grinding ...
In the case of the large SAG mill referred to in Fig. 1, the mill's initial volume is 757m 3 when new liners are installed, with the volume on average increasing to 792 m 3 at the end of shell ...
The comprehensive 360° mill vibration analysis is displayed as a real-time polar plot and estimates the position of the impact zone. The MillSlicer also determines a Liner Damage Level signal that can be used by the operator to minimise metal-on-metal impact and prolong liner and grinding media life.
In Mineral Processing Design and Operations (Second Edition), 2016. 8.3.1 Rod Mill Charge. Rod mill charges usually occupy about 45% of the internal volume of the mill. A closely packed charge of single sized rods will have a porosity of 9.3%. With a mixed charge of small and large diameter rods, the porosity of a static load could be reduced even further.
Mar 21, 2007· Similar to the impeller design affecting pump capacity, the pulp lifter design affects the discharge capacity (or mill throughput) of AG and SAG grinding mills. Generally, the discharge from AG/SAG mills consists of one or both of the following components: slurry (water and finer particles) and pebbles (20-100 mm).
The charge level of a mill can be described as the volume occupied by the grinding media (including empty spaces) as a fraction of the total volume avail-able inside the equipment. Assuming this definition, other measurements may be taken considering the total charge that includes the rock charge; in this case, applicable to SAG and AG mills.
The PSD from multiple revolutions of AG/SAG mill surface vibration data has been shown to be a good bulk spectroscopic inferential measure (particularly in terms of frequency band power) of what ...
A further attempt to measure inside the mill was detailed by Martins in his doctoral thesis at McGill University Montreal, Quebec. Martins presented the study of an instrumented ball, a camera system and a DEM analysis to propose mill entropy measurement. The system was successful in laboratory scale with wood and plastic as the mill charge.
However in sag mills and in partcular ag mills the grinding media derive from the feed ore. The feed ore hardness and size distribution therefore dictate the number and size distribution of the grinding media which will vary greatly from mill to mill and ore type to ore type.
Mar 09, 2021· Additionally, it is difficult to measure the internal physical parameters of charge (grinding media and iron ore) temperature inside the mill because of the harsh environment itself. Therefore, to understand the mechanism of heat transfer and improve the grinding efficiency, the heat transfer model should be established and the thermal breakage ...
It also monitors the particle size of the material entering the mill, enabling the intelligent software to calculate the optimum mill load target based on current liner and ore parameters. The aim is to maximize volume while ensuring that input energy is used efficiently to reduce particle size, giving you optimum mill performance.
Effects of grinding media shapes on load behaviour and mill power ... mills. To a large extent the focus has been on how grinding media shapes affect milling ... An inductive proximity probe was used to determine the load orientation of the grinding media .... Material properties such …
Jan 01, 2015· In a SAG mill, the ore itself along with steel grinding media is used to grind ore from 200 mm down to 0.1 mm as a means to liberate the valuable minerals (Wills & Napier-Munn, 2006). In these mills, total charge volume occupies approximately 35% of the mill interior, and the charge is lifted by lifter bars along the interior of the mill shell ...
How To Calculate Charge Volume In Ball Or Rod Mill. Calculation for filling of grinding media charge calculating volume of grinding media charge to calculate grinding media charge for continuous type ball mill m 0000676 x d2 x l example to calculate grinding media charge for a 180 cm dia x 180 cm long batch type ball mill with duralox 50.