Ball mill media optimization - Metcom Tech

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 grinding, and needs to be adjusted for those applications. Other guides (e.g. Azzaroni,

BOND'S WORK INDEX: WHAT IT IS AND WHAT IT ISN'T

The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of –0.45 in the 100 µm to 200 µm size range, not the –0.50 exponent empirically measured by F. Bond. The work index increase between 100 µm and 76 µm is due to a porphyritic grain size that causes a spike in energy

Relationships between comminution J energy and ... - …

Table I shows the Bond ball mill work index obtained for the ore samples as well as the iron and silica content in concentrate and tail after LIMS. The concentrate weight recovery was in the order of 50–60%. Furthermore it may be observed that the Bond ball mill work indices for the ore (Wi) varies from 14.6 to 20.9 kWh/t.

THE BOND WORK INDEX OF LIMESTONE AND ANDESITE …

THE BOND WORK INDEX OF LIMESTONE AND ANDESITE MIXTURES** Abstract This paper investigates grinding of mineral mixtures with different grindabilities in the Bond ball mill. Understanding the ore mixture grinding is of great …

Determination of Bond Work Index of Lucky Cement …

In this regard calculation of work index of limestone made by standard Bond grindability test. Ball mill was employed to conduct the grinding test of seven different samples. Among all seven samples collected from the different faces of quarry, Bond work index of limestone Face4A results less than 20kwh/t, remaining 6 samples are marked as hard -

SIZE REDUCTION - Universiti Teknologi Malaysia

Bond's Law: work required using a large-size feed is proportional to the square root of the ... The work index for limestone is 12.74. kW P D mm D mm m pb pa 169.6) 50.8 1 3.175 1 ... 10 kW is needed to operate the empty mill. By reducing the clearance between the crushing head and the cone, the differential screen analysis of ...

JKTech Technical Article

• Grindability as indicated by the bond ball mill work index (BWi) ranged from 10–35 kWh/t, with the majority between 15 and 27 kWh/t. No clear relationships in terms A*b and/or BWi was identified with geological aspects logged from the drill core such as weathering, lithology, alteration, alteration intensity, veining or combinations of these.

JK Bond Ball Mill Test - JKTech

JK Bond Ball Mill Test Since its introduction in the 1960s, the Bond Ball Mill Work Index (BBMWi) parameter has been extensively used in predicting ball mill power draw. Use of Work Index Along with comminution circuit design the work index parameter is widely used in tracking mill performance. Due to the age and lack of controls for the test,

The MiniBond test: description, calibration and sources …

Bond ball mill work index test, in order to have a quantitative evaluation of the success of any alternative test. Consequently, this paper presents a new test, termed the MiniBond test. The new test has more than 80 individual calibration points collected over a range of ore types, ore deposits, and closing screen sizes.

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 ...

(PDF) Determination of Bond Work Index of Lucky Cement ...

Index Terms — Ball mill, Bond Work Index, Comminution, Grindability, Liberation, Limestone, Ultra-fine particles 1 I NTRODUCTION N a mineral process ing plant, comminutio n …

20150505 Bond Efficiency-GMG-ICE-v1-r04 Determining …

Where, WioACTis the Actual Operating Bond Work Index (kWh/t), W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the 80% passing size of circuit feed (µm). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal

(PDF) The Bond work index of limestone and …

In this study, It is secured calibration data for the Bond's work index of Korean desulfurization limestones according to the mining location with the standard …

AMIT 135: Lesson 7 Ball Mills & Circuits – …

Mill Type Overview. Three types of mill design are common. The Overflow Discharge mill is best suited for fine grinding to 75 – 106 microns.; The Diaphram or Grate Discharge mill keeps coarse particles within the mill for additional …

Bond Work Index Tables (Wi) | PDF | Rock …

Bond Work Index Tables (Wi) - Free download as PDF File (.pdf), Text File (.txt) or view presentation slides online. Here there are given tables from various sources for the Bond work index values of mining materials (ores, …

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

submitted to the Bond ball mill work index test. The number of SAG mill revolutions required to grind the material to a P 80 of 1.7 mm is used to predict AG/SAG specific energy using quation 4. Correction E factors for feed size and pebble ing are applied to the AG/SAG specific energy, as well as specific crush

Bond Work Index Report Matrix House

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. 2. Procedure 2.1. Bond Ball Mill Grindability The sample was crushed to passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.

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

The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis to another. The proposed model consists of two components, the variable coefficient that is determined from a specific work index determination and a fixed exponent determined by a calibration procedure.

Characteristics of Mae Moh lignite: Hardgrove …

test using ball-race test mill was performed. Knowing the Hardgrove indices, the Bond work indices of some samples were estimated using the Aplan's formula. The approximate work indices were determined by running a batch dry-grinding test using a laboratory ball mill. Finally, the work indices obtained from both methods were compared.

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 ...

Investigation into the applicability of Bond Work Index ...

Bond Work Index (BWI) & Hardgrove Grindability Index (HGI) tests for biomass & coal. • BWI can predict the potential for mill choking of biomass in a tube and ball mill. • HGI is a poor method of predicting grindability of biomass in vertical spindle mills. • Pellets should be composed of pre-densified particles close to the target size. •

USING THE SMC TEST® TO PREDICT COMMINUTION …

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, 2004. a) 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 ...

GMSG GUIDELINE: DETERMINING THE BOND …

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

Bond Work Index Procedure and Method

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 equation application methods are used to process <1/2″ ore samples in a Ball Mill using a standard ball charge.. Below describes in general terms the Bond Work Index Procedure used by a Professional …

Improved characterisation of ball milling energy ...

The Bond Ball Mill Work index (BBWi) is the industry standard procedure for assessing the grindability of ores. The test involves conducting a locked-cycle grinding test using ond's standard mill design. The locked-cycle test enables a batch process to emulate the grinding behaviour of a continuous mill