Calculate Top Ball Size of Grinding Media Equation amp Method. Although it was developed nearly 50 years ago Bond s method is still useful for calculating necessary mill sizes and power consumption for ball and rod mills This paper discusses the basic development of the Bond method the determination of the efficiency correction factors based on mill dimensions and …

The Work Index is used when determining the size of the mill and grinding power required to produce the required ore throughput in a ball mill [Bond 1961].

grams per revolution (Gbp) is the ball mill grindability. The ball mill work index, Wi (kWh/short ton) is calculated from the following equation (Bond 1961):1 The mill should be cleaned by either blowing air into it or wiping the interior with a cloth and or brush. The FC Bond ball mill is now ready for the next sample.

This study was carried out in a standard bond ball mill 305 mm x 305 mm size in mineral processing laboratory, in the mining engineering department at King Abdulaziz University, KSA as shown in Figure 2. Grinding media of steel balls weighing 20.5 kg has been used. The details of the mill charge are given in Tab le 1.

This paper compares the performance of a 25/75 pebble/ball (volume ratio) composite charge to ball-milling, under conditions typical for a ball-mill in SABC circuits, i.e. a large ball top size (75 mm), a high mill speed (75% of critical speed) and a coarse feed top size (19 mm).

Ball Mill Design Parameters Size rated as diameter x length. Feed System One hopper feed Diameter 40 – 100 cm at 30 ° to 60 ° Top of feed hopper at least 1.5 meter above the center line of the mill. Feeder Single or double helical scoop feeder or a spout feeder Double helical feeders used in closed-circuit with classifiers

ball mill sizing with bond method work index base A comparison of the Bond method for sizing wet tumbling. · A comparison is made of the results from a ball mill model simulation with those of the conventional Bond ball mill design method, for a material whose breakage characteristics and Work Index have been determined.

dard Circuit, assume 2.44 m diameter overflow mills, and use a rod mill F80 of 16,000 µm and a rod mill P80 of 1,000 µm. Note that—in order for no correction factor for ball mill product fineness to apply—the ball mill circuit P80 should be …

The grinding-product size, P, in a Bond ball mill, which is given by the aperture size which passes 80% of the grinding product as a function of the …

savings compared to conventional ball milling. The HPGR and air classification circuit used 20 – 30 % less energy than the HGPR, screen, ball mill circuit. While VRM was estimated to use 10 – 30 % less energy (depending on the type of VRM) than a ball mill circuit for a …

At result B = 25mm or less necessary to use the correction factor 1.3, i.e. the grinding balls average diameter should be 32.5 mm in the feed mixture. We draw your attention, a larger grinding balls need to use for future loads.

Factors Affecting Ball Mill Grinding Efficiency. 25/10/2017 The following are factors that have been investigated and applied in conventional ball milling in order to maximize grinding efficiency: a) Mill Geometry and Speed – Bond (1954) observed grinding efficiency to be a function of ball mill diameter, and established empirical relationships for recommended media …

The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5′ x 5′ Ball Mill has a working diameter of 5′ inside the liners and has 20 per cent more capacity than all other ball mills designated as 5′ x ...

A comparison of the Bond method for sizing wet tumbling ball mills with a size—mass balance simulation model. ... A comparison is made of the results from a ball mill model simulation with those of the conventional Bond ball mill design method, for a material whose breakage characteristics and Work Index have been determined. ...

The Bond Index conforming rod charge consists of: 6 rods of 1.25" diameter and 21" length. 2 rods of 1.75" diameter and 21" length. The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.

First, a Jar Mill grindability test requires a 5 lb. (2 kg) sample and produces a direct measured specific energy (net Hp-hr/t) to grind from the design feed size to the required product size. The second test, a Bond Work Index determination, results in a specific energy value (net Hp-hr/t) from an empirical formula.

At Cadia the first Vertmill sizing was based on a Bond Wi of 16 kwh/t ten years ago the ore BWi is now 18.5 kwh/t after ten years so if you turn up at site and compare what the Ball mill or Vertimill or SAG is doing now with what it was sized based on ten years then for sure they are all under-performing 15%.

The method is used to size a cement ball mill. Efficiency correction factors are applied with the Bond equation. The method is valid both for clinker grinding and for raw materials grinding. This method only gives a rough and initial idea for sizing a cement ball mill.

Corrected Ball Mill Feed, and 3. T2': the particle size distribution of the Corrected Ball Mill Feed. With two equations and three unknowns, there are several solutions to equations [5] and [6], depending on the value attributed to the Fines Factor (Q1), each yielding different Corrected Ball Mill Feed Size Distributions (T'2). This is

size of the feed and the product ( m), respectively. Bond developed a standard laboratory test for the determination of the work index for ball and rod mills in 1952 and modified it in 1961. The standard Bond ball mill grindability test is a closed circuit dry grinding test with a 250% circulating load. The standard procedural outline of the

ball mill sizing with bond method work index base A comparison of the Bond method for sizing wet tumbling. A comparison is made of the results from a ball mill model simulation with those of the conventional Bond ball mill design method, for a material whose breakage characteristics and Work Index have been determined.

The Bond Index for Ores a You wish to estimate the size of a grinding mill without making any actual grinding tests. Using the Bond Work Index Wi for each material as given in the Lecture Notes, calculate the approximate kWhr per short ton needed to grind the following average materials from 4 mesh 4699 μm to 200 mesh 74 μm: 1

mill charge. The media sizing formula of Bond is the proven calculation to confirm the required media size. B Ø (mm) = 20.17 · C Ø (mm) = 18.15 · B ball diameter in (mm) C Cylpebs diameter in (mm) F size of mill feed in micron, 80 % of new mill feed passing Wi Bond Work Index (KWh/t) Cs per cent of critical mill speed (%)

mill charge. The media sizing formula of Bond is the proven calculation to confirm the required media size. B Ø (mm) = 20.17 · C Ø (mm) = 18.15 · B ball diameter in (mm) C Cylpebs diameter in (mm) F size of mill feed in micron, 80 % of new mill feed passing Wi Bond Work Index (KWh/t) Cs per cent of critical mill . Get price

The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index. For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill (see Figure 3.10), a question arises as to whether this practice will alter the ball mill work index (BW i) of the …

The Bond_Mill Sizing spreadsheet was designed to determine the most appropriate mill dimensions and operating conditions for a given grinding task (known ore properties plus desired mill throughput and feed and product sizes), based on the traditional Bond's Law and the Hogg & Fuersteneau Power Model (see Mill Power_Ball Mills spreadsheet for ...

Ball mill charge size distributions originally specified for Bond grindability tests to determine the Bond Work index (BWi) are not commercially available. Those proposed to date do not match all of Bond's (1961) original specifications of total ball mass, number and surface area.

The High Energy Ball Mill Emax combines high-frequency impact, intensive friction, and controlled circular jar movements to a unique and highly effective size reduction mechanism. The grinding jars have an oval shape and are mounted on two discs respectively which move the jars on a circular course without changing their orientation.

validity of each theory within a certain particle size range. This study illustrated that Kicks law was applicable in the crushing range (above 1 cm in diameter) . Bond's theory was more suited to the particle size ranges involved in conventional ball and rod mill grinding (5 to 250 mm). Rittinger's law showed more _app1icability to the fine

The Bond test applies a standardized ball mill of 305 mm (12 in.), both in diameter and length, with a grinding media charge of certain size distribution and operated at a defined speed. The sample amount is defined by the bulk volume …

The Ball Mill Charge: Clean the Ball Mill and accessory equipment before starting. Count and weigh the Balls by sizing group. Record the results on the Ball Count and Charge Weight Determination form. Determine a charge weight made up of exactly 285 steel Balls weighing as close to 20,125 grams as possible.

Well, this safety factor can cost you much in recovery and/or mill liner wear andBall Mill Design/Power Calculation,19/6/2015· 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 ...

A Bond ball mill work index is then performed on the mill product for the design of SAG-ball mill circuits. This is important because it was found that there was a 1–1.5 kWh/t higher ball mill work index if the –3.35 mm ball mill test feed size is obtained by SAG mill grinding compared with crushing.

Bond equation of cement ball mill sizing. Nov 12, 2015 · The method is used to size a cement ball mill. Efficiency correction factors are applied with the Bond equation. The method is valid both for clinker grinding and for raw materials grinding. This method only gives a rough and initial idea for sizing a cement ball mill.

Ball Mill Design/Power Calculation. Jun 19, 2015· 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 …

El archivo "Bond_mill_Sizing.xls" cuenta con dos hojas: 1. About. Puede encontrar descripción programa que incluye marco teórico, entrada datos, ejecución programa y sugerencias útiles. 2. Data_File. En esta hoja se realizan los cálculos, para ello ingresar datos sobre geometría molino, condiciones operación, características mineral ...