## Bond Work Index Procedure and Method

Jun 06, 2015 · This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six mesh or finer feed ore samples. These

## Correction of Bond Ball Mill Work Index Test for Closing ...

Dec 07, 2018 · It is commonly known that one must run the Bond ball mill work index test such you pick a closing mesh to give a P80 close to desired grind size. This is because work index frequently changes as a function of the product size in comminution. If target grind size during a project is changed, or if the test is run at the wrong product size, then ...

## Bond Work Index - an overview | ScienceDirect Topics

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 material ...

## QUICK METHOD FOR BOND WORK INDEXAPPROXIMATE

The aim of this study was to develop a new method for assessing the Bond work index in a ball mill (BBWI), which is based on a first order kinetics present in the Bond ball mill for grinding mineral raw materials (Austin et al., 1981; Ahmadi and Shahsavari, 2009). Theoretical basis of quick procedure

## GMSG GUIDELINE: DETERMINING THE BOND EFFICIENCY OF ...

Bond Test WI’s (kWh/t): Rod Mill: Ball Mill: 9.5 kWh/t.8 9 kWh/t . Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 mµ (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod µ

## 20150505 Bond Efficiency-GMG-ICE-v1-r04 Determining the ...

Wi Bond Work Index (kWh/t) WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index ... size coarser than the plant ball mill circuit P80. If choos-ing between two standard mesh sizes, choose the finer ... dicted by the Bond design/scale-up method for the

## MODELING THE SPECIFIC GRINDING ENERGY AND BALL-MILL

21 CONCLUSIONS Continued In the present work, equations were also derived, giving: zthe ball-mill power drawP as a function of its dimensions: internal mill diameter D and length L, zthe ball-mill power drawP as a function of the feed D f (mm) and the product size d (mm), the Bond work index w i (kWh/short ton) and the mill throughput T (short ton/h), zthe ball-mill dimensions (D and L), when ...

## Orway Mineral Consultants Canada Ltd. Mississauga, ON ...

Drop Weight Index (DWi) and the coarse ore grinding index (M ia). Test data from the Bond ball mill work index test is used to calculate the fine grinding index (M ib). The M ia and M ib indices are used to calculate specific energy for the coarse (W a) and fine (W b) components of the total grinding specific energy at the pinion (W

## Ball mill media optimization - Metcom Tech

B Recommended make-up ball size, inches. F80 Circuit feed 80 percent passing size, microns. K A constant, 350 for wet overflow mills, etc. WI Bond test Work Index, kWh/short ton. SG Ore specific gravity. Cs Mill speed in percent of critical. ID Mill inside (liners, working) diameter, feet. It pre-dated (semi-)autogenous

## Bond Work Index - an overview | ScienceDirect Topics

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 material ...

## DETERMINATION OF THE BOND’S WORK INDEX OF

The work index expresses the resistance of the material to grinding. It represents the kilowatt hours per tonne required to reduce the material from theoretically infinite feed size to 80 passing 100μm (Wills and Napierpercent -Munn, 2006). Bond devised several methods for predicting ball-mill and rod-mill energy requirements and

## Procedure for determination of ball Bond work index in the ...

The Bond ball mill grindability test is run in a laboratory until a circulating load of 250% is developed. It provides the Bond Ball Mill Work Index which expresses the resistance of material to ...

## Application of Operating Work Indices in Autogenous ...

Ball Mill Wio, BWio 8.6 Circuit Wio, OWio 14.6 Bond Ball Mill Work Index, BWi, kWh/t 13.4 Bond Rod Mill Work Index, RWi, kWh/t 18.1 Table 1. Example of AG/SAG Ball Mill Circuit 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 ...

## Calculating Power Draw when sizing Ball Mills - Grinding ...

The discussion you have initiated is very interesting indeed. I too am not an expert in ball mill sizing but from what my general understanding goes, method to calculate Bond's Work Index (WI) takes into consideration a 250% circulating load and ball mill sizing is based on the WI.

## O. I. SKARIN N. O. TIKHONOV CALCULATION OF THE

Standard size ranges and the related Bond work indexes Feed size F 80, μm Product size P 80, μm Work index 100000 10000 crushing CWI 10000 2100 rod milling RWI 2100 100 ball milling BWI Fig. 1. Laboratory equipment used by RIVS for determining the Bond work

## Bond Grinding Circuit Efficiency - ceecthefuture.org

Mill Ball Mill Closed circuit crushing to 16 mm Open circuit 8’ dia. rod mill to 1 mm Closed circuit 8’ dia. ball mill to P80 um The ore Test Work Index = Circuit Operating Work Index 9 The Standard Bond Circuit Coarse Ore Bins Fine Ore Bins Screen Crushing Screen Classification Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL WORK ...

## Grinding Mill Computer Model

3.3 Ball Mill Design The ball mill designs also follow the Bond/Rowlings method with comparison with other methods. Again the method of use is the same 3.4 SAG/BM Combined design This is the combined model of the SAG and BM models. The difference is that a provision in the BM model allows for the fact that finished product is in the BM feed.

## Bond Index & Hardgrove Grindability Index Tests for ...

Test conducted on a Bond Index testing mill (Bico-Braun, USA) 700ml of sample milled for 100 revolutions. New number of revolutions is calculated to produce fines equal to 1/3.5 of the total charge of the mill. The Bond Work Index W i expresses the resistance of the material to grinding to a specified product size (kWh/ton) The Work Input W ...

## Characteristics of Mae Moh lignite: Hardgrove grindability ...

For the simplified Bond method, an approximate work index may be determined by running a batch dry-grinding test. The test was performed using a 25 cm diameter tumbling ball mill with material hold-up of about 10%, media loading of about 25% and a unit interstitial filling. Two kilograms of the 5 mm lignite samples were ball-milled for 10 ...

## Ball Mill Design/Power Calculation

Dec 12, 2016 · 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 ...

## SAGMILLING.COM .:. Articles

Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes It is commonly known that one must run the Bond ball mill work index test such you pick

## sizing of ball mill based on grindability index

Grindability Index Test Method & Procedure - 911Metallurgist The proposed grindability test uses the Bond standard test mill and a .... Energy required For grinding: comparison of plant data, estimates based on the Bond Work ...size to another. it can be expressed in different ways, the best known being the ... in a laboratory hatch ball mill, and the times required for each material to be ...

## Determination Of The Bond Work Index Using An Ordinary ...

Numerically, the work index is the energy required in kwh/t to reduce a given material from theoretically infinite feed size to 80% passing 100 microns. The work index of a particular material is determined in the laboratory by conducting the standard Bond grindability test. Bond developed separate tests for the rod mill and the ball mill.

## A comparison of the Bond method for sizing wet tumbling ...

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. In order to ...

## P80 of Bond ball mill Work Index tests

Dec 04, 2020 · The laboratory procedure for running a Bond ball mill work index test requires that the operator choose a closing screen sieve size. The instruction is to

## A new approach to Bond grindability and work index ...

Mar 01, 2003 · W i =1.1× 44.5 P i 0.23 G bg 0.82 10/ P 80 − 10/ F 80 W i is the work index (kwh/t); P i, screen size at which the test is performed (106 μm); G bg, Bond’s standard ball mill grindability, net weight of ball mill product passing sieve size P i produced per mill revolution (g/rev); P 80, sieve opening which 80% of the product passes (μm ...

## Determination of the Bond work index on samples of non ...

Nov 21, 2012 · The Bond work index, W i, is defined in a Bond ball mill on the samples of standard size − 3.327 + 0 mm. In practice, it is possible to find materials of non-standard size that are finer than 3.327 mm.. In this work, a procedure for the calculation of the Bond work index is suggested for cases when the Bond grindability test is conducted on samples of non-standard size.

## Product size distribution function influence on ...

Dec 10, 2016 · Differences up to 6,2% in the Bond ball mil work index can be observed due to different siz distribution in P 80 calculation.. 13 ores were tested using the Bond ball mill grindability test, obtaining P 80 using different interpolation functions. Rosin Rammler’s model showed the best behavior, so its use must be not only suggested, but recommended.

## C O N S U L T I N G L T D TECHNICAL MEMORANDUM

EF5BM=[ P80+10.3 1.145×P80] ( 3 ) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a “single-stage ball mill” calculation, the F80 is actually the rod mill feed size (10,000 µm) from Table 1 and the P80 is the ball mill circuit product. The EF5 factor only applies below 75 µm to ball

## General work input function for sizing grinding ball mills ...

Nov 01, 2002 · Equations for power draft, capacity and work input for predicting the performance of industrial grinding mills are derived based on torque measurements using a laboratory instrumented mill. These derivations are based on mechanical principles and on the first-order kinetics of the grinding process. Rittinger’s, Kick’s and Bond’s laws express work input as work index (Wi) times a particle ...

## A CRITICAL REVIEW OF GRINDING DESIGN PROCEDURES FOR

Jan 08, 2021 · energy, using Bond equations. Its value is determined in the MacPherson Test or as an operating work index by using values from an operating circuit. Its value is only valid at the stated SAG product size. • Transfer size (T80) is the term used to describe the SAG mill product that is sent to the ball mill. For peak performance and balancing ...

## Technical Information - SMC Testing

However, if the sample is to be prepared by cutting with a diamond saw (cut-core method) as little as 5kg is normally sufficient. Also remember that the products from the SMC Test® can be re-used for Bond ball work index testing, the SMC Test® being effectively used as a feed preparation step for the Bond ball work index test.

## Operating work index is not the specific energy consumption

Oct 24, 2018 · However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameter-Kwhr/m3-, so it

## Using modelling and simulation for the design of full ...

Dec 01, 1997 · Table 2 gives details of the Bond laboratory ball mill. 1320 S. Mormll and Y. T. Man Ball Mill I1_ Fresh feed ~-~ ~_. r~ ~ ~-~ ~ size Screen u/size Ball mill discharge Fig.4 The flowsheet of the Bond ball mill test TABLE 2 Bond ball mill details Diameter (m) Length (m) Speed (rpm) Speed (fr. crit) Ball load (%) Ball top size (mm) 0.305 0.305 70 ...

## Model:Morrell Mi SMC SAG - SAGMILLING.COM

The method requires all the elements of the ball mill work index test to be filled in: Ball mill Wi test closing screen size, umclosing, µm; Ball mill Wi test product size, P 80, µm; Ball mill Wi test feed size, F 80, µm; Ball mill Wi grams per revolution at test conclusion, gpr; Required parameters. F 80, µm is the 80% passing size of the ...

## (PDF) Determination of work index in a common laboratory mill

A comparative analysis was made with simulation results, using various methodologies, of the ball mill Bond test based on real values of the work index. This analysis was carried out with various ...

## (PDF) Rapid determination of Bond rod-mill work index by ...

The exper- method, the t-test is performed on work index values by the two iment results confirm that the introduced method is a rapid and methods in respect of the standard Bond method. Tables 3 and 4 accurate method to determine the Bond rod-mill work index.