• Application of Operating Work Indices in Autogenous

    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 profitability. Mill operators have long used operating

  • How to Measure Grinding Efficiency

    The first two Grinding Efficiency Measurement examples are given to show how to calculate Wio and Wioc for single stage ball mills. Figure 1. The first example is a comparison of two parallel mills from a daily operating report. Mill size 5.03m x 6.1m (16.5′ x 20′ with a ID of 16′).

  • Factors Affecting Ball Mill Grinding Efficiency

    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 size and mill speed that take this factor into account.

  • Bond Grinding Circuit Efficiency

    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

  • How to Improve Ball Mill Performance

    Ball mill circuit classification system performance is considered here first because it provides the basis for subsequent characterization of ball mill breakage efficiency. Major design and operating variables in closed circuit ball milling of a specified feed to a desired product size are summarized in Table 1.

  • ball mill operatng work index calculation

    ball mill operatng work index effeciency. ball mill operatng work index effeciency A more sustainable approach to assessing comminution efficiency The Bond operating work index is in common use for assessment of comminution efficiency This method was developed for rod and grinding ball . Contact Supplier

  • Operating work index is not the specific energy consumption

    24/10/2018· The work index can either be measured in the laboratory (the Bond ball mill work index determination is a common example) or it can be calculated from the operating performance of a milling

  • (PDF) A quick method for bond work index approximate value

    The Bond work index, Wi, 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

  • Bond Work Index Formula-Equation
    Basic EquationsSize Distribution and Exposure RatioEquations For Work Index VariationsWork Index and Crack EnergyThe basic work index equation is:W = 10 Wi/√P – 10 Wi/√F(1)where W is the work input required in kilowatt hours per short ton to grind from 80% passing F microns to 80% passing P microns, and Wi is the work index, or the grinding resistance parameter. It represents the energy input required in kilowatt hours to reduce a short ton from theoretSee more on 911metallurgist
  • Orway Mineral Consultants Canada Ltd. Mississauga, ON

    Bond’s approach consists of determining the ore hardness characteristics, or Work Index (Wi) via standardized laboratory testwork. The full suite of Bond comminution tests provide the Ball Mill Work Index (BWi), the Rod Mill Work Index (RWi), the Crusher Work Index (CWi) and the Abrasion Index (Ai). Over the years, it has been determined that

  • (PDF) A quick method for bond work index approximate value

    The Bond work index, Wi, 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

  • Calculate a Mill's Operating Work Index

    Use this online formula to calculate a Ball Mill, Rod Mill or SAG Mill Operating Work Index. Based on Fred Bond’s work you can estimate the energy used into your grinding circuit. This is the most accurate and informative method, but much of the data necessary for its application is not yet available. A) Total Apparent Volumetric Charge Filling including balls and excess slurry on top of


    two. Results of Bond ball mill tests conducted with closing screens of 75 µm or finer are to be treated with caution. The Bond Work Index relationship has been noted to apply down to approximately 70 m, and perhaps no finerµ,without making qualifications. Calculations: First, calculate the actual Operating Work Index, WloACT-, of the


    In the prerequisite module entitled "Work Index Efficiency", you have learned about work index analysis* to define overall grinding circuit efficiency. In rod milling, you can use work index analysis to relate design and operating variables to overall circuit efficiency. However, you cannot use work index analysis for the same purpose on ball mill


    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

  • Bond Tests Mining SGS

    Bond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond’s Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standard rod mill. It can be

  • Bond Ball Mill Index Test JKTech

    A Bond Ball Mill Work Index may also be used in the simulation and optimisation of existing mill(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 the Bond Ball Mill Work Index test

  • Index Bond Ball Mill haagdeko.de

    Application Of Operating Work Indices In Autogenous . 2015-12-16ball mill wio, bwio 8circuit wio, owio 14bond ball mill work index, bwi, kwht 13bond rod mill work index, rwi, kwht 18table 1xample of agsag 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.

  • Model:Bond HPGR and ball mill SAGMILLING.COM

    where CF is the Es calibration factor (in the Circuit Settings) for ball mill operating work index versus laboratory ball mill work index. A value of zero means use the Bond/Rowland S formula to predict E ball, a value of -0.05 means use 5% less than Bond/Rowland S formula to predict E ball. CF is a negative number if Wi O is less than

  • The operating principle of the ball mill

    The operating principle of the ball mill consists of following steps. In a continuously operating ball mill, feed material fed through the central hole one of the caps into the drum and moves therealong, being exposed by grinding media. The material grinding occurs during impact falling grinding balls and abrasion the particles between the balls.


    lifter configurations and operating parameters on the mill efficiency and performance. The MillTraj software was also utilized to simulate the outermost charge trajectories in terms of lifter profiles and mill speeds. For the mill with higher mill load and lower speed, the power draw of the mill differed slightly for the different lifters with the same face angles of 20o. Rail lifter drew


    work index covering grinding of fine particles is labelled M ib (Morrell, 2008). M ia values are provided as a standard output from a SMC Test® (Morrell, 2004a) whilst M ib values can be determined using the data generated by a conventional Bond ball mill work index test (M ib is NOT the Bond ball work index). M ic and M ih values are also

  • Model:Bond/Barratt SAB Model SAGMILLING.COM

    The resultant operating work index of the ball mill will vary according to the ratio of the ball mill, rod mill and crushing work index values and for an Andean copper porphyry is typically in the range of 80% of the measured ball mill work index value. Testwork Required. Bond ball mill work index; Bond rod mill work index

  • Mill (grinding) Wikipedia

    Rod mills are less common than ball mills for grinding minerals. The rods used in the mill, usually a high-carbon steel, can vary in both the length and the diameter. However, the smaller the rods, the larger is the total surface area and hence, the greater the grinding efficiency. Autogenous mill

  • Benchmarking: Morrell Mih Tropicana SAGMILLING.COM

    Predicts 1% increase in ball mill operating work index (17.75) versus laboratory Wi (17.5). Discussion. The comparison of predicted specific energy consumption versus

  • Bond Work Index Tests Grinding Solutions Ltd

    Bond Work Index Tests. Grinding Solutions offers a range of Bond Work Index Testing from crushability and abrasion to ball and rod mills. For more information on the tests please see below: Bond Low Energy Impact Test. The Bond Low-Energy Impact test can be used to determine the Crusher Work index (CWi), also known as the Impact Work Index. The

  • Operational work index for grinding plants ScienceDirect

    The results may be extended to other grinding plants. Keywords: grinding plant, work index, operational work index, soft-sensors Introduction The concept of operating work index, Wiop, has been used to evaluate the efficiency of a grinding circuit (Rowland, 1973). Work indices obtained from operating data on any mill can be compared to

  • 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

  • Fine grinding in a horizontal ball mill ScienceDirect

    Because of this, grinding below 25 μm in a horizontal ball mill is not practicable. The aim of this experimental work was to study the effect of ball size on the feed and product size distributions in a ball mill fine grinding situation. 2. Mill feed/ball size distribution

  • Ball mill Wikipedia

    A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints.Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls.