The work index . W. i. was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate ... Finally the product is wet screened to find the size d80. 2.2. Ball Mill Batch Process The mill dimensions, (D × L), are 0.204 × 0.158 m and it ... The 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 Metallurgical Testing Laboratory.

2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALL-MILL SCALEUP Ball-mill scale up (Bond’s Law)Data: zBond work index w i zFeed D f and product d size (both 80% cumulative passing) Result: The specific grinding energy w Mill power draw P = wT, where T the mill capacity Mill dimensions (from Tables or charts)

Determination of Bond Index of Wasagu Manganese Ore in Kebbi State, Nigeria. ... the work index of Wasagu Manganese Ore deposit in Kebbi State of Nigeria was determined using the modified Bond’s Method of determining work index also known as Berry and Bruce method. ... out and 80% passing particle size of the ball mill feed and discharge for ...

Presently, power-based equations remain the principal method for designers to size mills and estimate the power requirement for comminution circuits. The technique is simple and it relies on the ... submitted to the Bond ball mill work index test. The number of SAG mill revolutions required to grind 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 ...

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] ... alternate method to correct for the transfer size effect. The method has similarities to the Phantom Cyclone technique, as it is also based on the decomposition of the transfer

how to determine the bond work index using lab ball mill grindability tests. Article in Engineering and Mining Journal 188(2):42-45 · February 1987 with 402 Reads Cite this publication

Number, size and mass of each ball size depends on mill load and whether or not the media is being added as the initial charge. For the initial chargin of a mill, Coghill and DeVaney (1937) defined the ball size as a function of the top size of the feed, i.e., d↓V = 0.40 K√F dB = ball size (cm) F = feed size (cm)

W is the work index measured in a laboratory ball mill (kilowatt-hours per metric or short ton) P 80 is the mill circuit product size in micrometers; F 80 is the mill circuit feed size in micrometers. Rod mill. A rotating drum causes friction and attrition between steel rods and ore particles.

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 quick method for the Bond work index approximate value determination, which is based on the first order grinding kinetics, is presented in this paper. ... is defined in a Bond ball mill on the ...

An improved method using less mass compared to the Bond Ball Mill Work Index test. The JK Bond Ball Mill (JKBBM) test, is a locked cycle grindability test conducted using a standard laboratory Bond Ball Mill with the same steel ball charge and material feed size ( passing 3.35 mm) as the Bond Ball Mill Work Index test.

Correlations for the Grindability of the Ball Mill As a Measure of Its Performance By ... standard equation used by them for the ball mill work index (Bond work index) is as follows. ... 2.2 Factors Affecting Size of Product from Ball Mill It is important to fix the point where the charge, as it is carried upward, breaks away from the ...

A study on the effect of ball diameter on breakage properties of clinker and limestone Vedat Deniz* ... required and mill size for a material. This method is complex and very lengthy. In addition, it is very ... Standard Bond Work Index tests were carried out for limestone and clinker samples and, the ...

A Bond Ball Mill Work Index test is a standard test for determining the ball mill work index of a sample of ore It was developed by Fred Bond in 1952 and modified in 1961 (JKMRC CO, 2006) This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required .

Characteristics of Mae Moh lignite: Hardgrove grindability index and approximate work index ... is a main parameter for mill sizing. Specifically, the Bond work index is suitable for utilization in ... For the simplified Bond method, an approximate work index may be determined by running a batch dry-grinding

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 provided as a standard output from a SMC Test® (Morrell, 2009). The general size reduction equation is as follows (Morrell, 2004b): 2 x 1x 4 2 1 xf W i M i x (1) where M i

A ball mill is a type of grinder used to grind and blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics and selective laser sintering.It works on the principle of impact and attrition: size reduction is done by impact as the balls drop from near the top of the shell. A ball mill consists of a hollow cylindrical shell rotating about its axis. T

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 ...

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

ball mill balls calculations bond Laboratory Ball Mill For Bond Work Index Procedure And Method . Laboratory Ball Mill For Bond Work Index Procedure And Method Xmgb Work in the ball mill, and steel balls of a certain size and number are put into the ball mill. repeatedly, and obtain the grinding work index kwh/t through calculation.

* Bond F. C., “Crushing Tests by Pressure and Impact”, Trans AIME, Vol 169, 1947, pp 58-66. 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.

Calculation of energy required for grinding in a ball mill ... The Bond work index, Wi, as an indicator of the grindability of raw materials is not a material constant but rather it changes with change of size …

Determination of Bond index of Birnin- Gwari Iron Ore in Nigeria ... ground using the laboratory ball mill grinding machine. 80% passing size for the iron ore ... The determination of work index using modified Bond’s method can be compared to method of determining it by Berry and Bruce (1966). ...

geous for being based on the Bond work indexes that are de-terminable in any well-fitted ore pretreatment laboratory (it is UDC 622.732 O. I. SKARIN (RIVS Science and Production Association) N. O. TIKHONOV (JV “IVS”) CALCULATION OF THE REQUIRED SEMIAUTOGENOUS MILL POWER BASED ON THE BOND WORK INDEXES O. I. SKARIN, Senior Researcher,

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.

1.. IntroductionA Bond Ball Mill Work Index test is a standard test for determining the ball mill work index of a sample of ore. It was developed by Fred Bond in 1952 and modified in 1961 (JKMRC CO., 2006).This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding, and for ball mill ...

conducted upon Gold Ore Samples from the Mt Todd Project Feasibility Study for ... 8.6 Bond Ball Mill Work Index Determination – Comminution Testwork Extension 51 ... Flowsheet – Sizing Testwork, Crushing <3.35 mm, Bond Ball Mill Work Index Determination

JKTech Laboratory Services Bond Ball Mill Index Test (BRMWI) A Bond Ball Mill Index Test (BBMWI) is a standard test for determining the Ball Mill Work Index of a sample of ore. The BBMWI is a measure of the resistance of the material to crushing and grinding. It can be used to determine

Alternative Approaches for Determination of Bond Work Index ... As a fast method, the determination of the Bond index from the Hardgrove index (by calculation) is almost matching with measured Bond’s work index. ... F80 is the size in microns at which 80 percent of the new feed to ball mill passes P80 is the size in micron at which 80 percent ...

Batu Hijau Model for Throughput Forecast, Mining and… used for design of the Batu Hijau grinding circuit is not discussed. Initial ore . The formula for calculating size corrected Point Load Index (Is50) is: D. P . 2 WiC = Bond Crusher Work Index, Wibm = Bond Ball Mill Index and Wirm = Bond Rod Mill Index. - 9 - .. spreadsheet rather than using the Continuous model program.

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 size as P80 and maximum and finally the type of circuit open/closed ...