design of bond rod mill work index

Commentary on the apparatus of theBondrodmillWorkIndex. by Alex Doll December, 2015 [email protected] TheBond"Third Theory" of comminution was originally divided into three size classes reflecting the varieties of comminution equipment common during the time period whenBond(and his collaborators) were gathering the information to calibrate comminution models.

BondRodMillGrindability Test. The test determines theBondRodMillWorkIndexwhich is used withBond'sThird Theory of Comminution to calculate net power requirements when sizing ballmills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standardrodmill.

BondRodMillGrindability Test. Grinding Solutions can carry outBondRodMillWorkIndextests to determine the energy requirements for milling ore in arodmill. The test requires a minimum of 20kg of -12.5mm material. Closing screen sizes typically range from 4.75mm to 212µm. AbrasionIndexTest

RodMillPower Draft.Rodmillpower is dependent onmillcapacity andworkindex.Millpower increases with: Increasingrodcharge; Increasingmillspeed; Increasingmilllength. Rowland and Kjos (1980) provided an expression to quantify power draw at the pinion shaft per unit mass ofrods: P↓M / M↓R = 1.752 D↑0.33 (6.3 - 5.4J↓R) Φ ...

See this useful summary Table ofBondWorkIndexby Minerals. For any circuit, whether a crushing circuit, arodmill, or a closed ballmillcircuit, theWorkIndexalways means the equivalent amount of energy to reduce one ton of the ore from a very large size to 100 um. The sample was received crushed appropriately for the ballmilltest.

The standardBondRodMillWorkIndextest procedure is firstly to stage crush the feed to pass 12.7 mm, and size a representative sample. The test then involves a series of batch grinds in a standardBondrodmill. ABondrodmillis 0.305m by 0.610m, with wave liners (ofa form described byBond), which runs at 40rpm and tilts as described below.

This Grindability Test orBondBallMillWorkIndexProcedure is used to determine theBondWorkIndexofminus six mesh or finer feed ore samples. These equation application methods are used to process <1/2″ ore samples in a BallMillusing a standard ball charge.. Below describes in general terms theBondWorkIndexProcedure used by a Professional Metallurgical Testing Laboratory.

The basic parameters used in ballmilldesign(power calculations),rodmillor any tumblingmillsizing are; material to be ground, characteristics,BondWorkIndex, bulk density, specific density, desiredmilltonnage 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 open/closed ...

RodMillWorkIndexTable Previous Next Here is a list presented in table form ofRodMillWorkIndexas tested/presented by SME handbook of mineral processing, N.L Weiss Editor, N.Y. 1985.

To calculateBondrod-millworkindices, the four samples were screened and the particle size distributions plotted in Fig. 2.The plot was used to find F 80 of the samples for calculations. Fig. 3, Fig. 4 show the grinding kinetics of Pb, Cu, Fe, and Mn ores in theBondrod-millin different test-sieves. The slopes of all lines in the figures are equal to the k value of Eq.

The grinding jar for theBondIndexRodMillis 12″ x 24″ in size and has a wave-shapeddesign. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball orrodmill. TheRodMillWorkIndex(RWI) is used for particle size determination in a size range from 25 mm down to 2.1 mm whereas BallMillWork...

The TitanBondWorkIndexRodMillis one-piece cast construction with integral wave liners of a form described byBond. Thismillis used to perform the necessary metallurgical testing to determine the grinding characteristics of ores and power requirements for operating production-sizerodmills.

Bond'sapproach consists of determining the ore hardness characteristics, orWorkIndex(Wi) via standardized laboratory testwork. The full suite ofBondcomminution tests provide the BallMillWorkIndex(BWi), theRodMillWorkIndex(RWi), the CrusherWorkIndex(CWi) and the AbrasionIndex(Ai).

standardBondcrushing, androdmillworkindices, abrasion indices and by Dawson forBondBallMillWorkIndextests using crushed feed, and Standard Autogenous GrindingDesign(SAGDesign) Tests, patented by Outokumpu. (See reference 8 below). The comparison of these results gives context to how the various measurements relate to each

TheBondrodmillworkindexis not as common as theBondballmillworkindex, and there are two different variations on themillapparatus.The SAGMILLING.COM models expect amillwith a "wave liner", and is not compatible withmillsusing "smooth liners".

Thedesigncharacteristics of industrialrodmillsare similar to ballmills. Mostrodmillsused in mineral processing are of the overflow discharge type as illustrated in Figure 7.2a. Centre peripheral (Figure 7.2c) and end peripheral dischargemills(Figure 8.1) are also in use.The feed end is generally fitted with spout feeders, scoop feeders, double scoop feeders or drum feeders.

No 1rodmill/ballmillcircuit was operating very effi ciently when comparing the combined operatingworkindices for bothmillswith therodmilland ballmilllaboratoryworkindices. Note, in Figure. 1, that therodmillproduct slope is less than 0.5 due to an extra amount of nes present being fi fi ner than 650 μm.

BondBallMillWorkIndex, BWi, kWh/t 13.4BondRodMillWorkIndex, RWi, kWh/t 18.1 Table 1. Example of AG/SAG BallMillCircuit Wio Calculations [1] [2] ABstrAct Optimum use of power in grinding, both in terms of grinding efficiency and use of installed capital, can have a large effect on profitability.

The MacPerson Autogenous Grindability Test determines the MacPherson Correlated AutogenousWorkIndex*. This can be used in conjunction with theBondRodand BallMillWorkIndices to determine power requirements, and to suggest circuit configurations for autogenous grinding (AG) and semi-autogenous grinding (SAG) circuits.

carried out with theBondballmillandrodmillgrindability tests. As discussed earlier in this paper, it is important in this case to match the reduction size of the test to that desired from the industrialmill. As such, primary ballmillsshould be designed with therodmillworkindex, and single-stage ballmillsshould

W is theworkindexmeasured in a laboratory ballmill(kilowatt-hours per metric or short ton) P 80 is themillcircuit product size in micrometers; F 80 is themillcircuit feed size in micrometers.Rodmill. A rotating drum causes friction and attrition between steelrodsand ore particles.

Generally,Bondworkindexis a common method for selecting comminution equipment as well as estimation of grinding efficiency and calculating required power. In the current research, a simple, fast and accurate procedure is introduced to find the

TheBondballmillworkindextest is thought to be additive because of its units of energy; nevertheless, experimental blending results show a non-additive behavior. [18] The SPI(R) value is known not to be an additive parameter, however errors introduced by block kriging are not thought to be significant .

Key Words: Comminution Tests,BondWorkIndices, JKTech, GrindingMillDesign, ... standardBondcrushing, androdmillworkindices, abrasion indices and by... More details » Get Price a fracture toughness based model for the prediction of power

ballmilland can be performed at mesh sizes ranging from 48 mesh to 400 mesh.BondBallMillWorkIndex(and modifiedBondWorkIndex) data can be used in the CEET® grinding simulator. • TheBondRodMillGrindability Test determines theBondRodMillWorkIndexwhich is used to determine net power requirements for sizingrodmills. The ...

21 CONCLUSIONS Continued In the presentwork, equations were also derived, giving: zthe ball-millpower drawP as a function of its dimensions: internalmilldiameter D and length L, zthe ball-millpower drawP as a function of the feed D f (mm) and the product size d (mm), theBondworkindexw i (kWh/short ton) and themillthroughput T (short ton/h), zthe ball-milldimensions (D and L), when ...

ABondBallMillWorkIndexmay also be used in the simulation and optimisation of existingmill(s) and the associated grinding circuit(s). Sample Requirements: A minimum of 8 kg of material crushed to nominally minus 10 mm is preferred. JKTech would stage crush the sample to minus 3.35 mm, as required for theBondBallMillWorkIndextest feed.

• thebondballmillworkindices determinations gave reasonably reproducible results, • significant variation was observed in the measurement of thebondrodmillworkindexon at least one sample tested, and • large variations in abrasionindexand crushingworkindexwere due to variations in the test method across the laboratories.

BondRodMillGrindability Test. The test determines theBondRodMillWorkIndexwhich is used withBond'sThird Theory of Comminution to calculate net power requirements when sizing ballmills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standardrodmill.