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.

According to the Bond standard procedure, the work index is determined by simulating a dry grinding in a closed circuit in the Bond ball mill to achieve 250% circulating load (Bond, 1949, 1952, 1961).

Comminution tests are important to establish the power consumption to grind the ore to the required size for liberation purposes. Bond Closed Circuit Grindability Tests Determining the Bond work indexes of a sample involves tests using laboratory scale grinding circuits.

The Bond rod mill grindability test is a widely used tool to estimate the response of ores to rod milling. However, the mass of ore required to conduct the test, which can typically vary from ...

Milling – Rod / Ball Mills including Bond Ball Work / Grindability Index . MARC manufactures a wide range of ball and rod mills to suit most metallurgical laboratory applications. Our range extends from small 6L jar-type mills that are manually positioned on rollers to large 30L size mills.

Essa manufactures a range of metallurgical laboratory size ball and rod mills to suit most applications. Included in the range is a Bond Index Mill, which has specific …

According to the Bond standard procedure, the work index is determined by simulating a dry grinding in a closed circuit in the Bond ball mill to achieve 250% circulating load (Bond, 1949, 1952, 1961).

The rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 mm (½ inch, the original test being developed in imperial units) to a product size of approximately 1 mm (in the original and still the standard, 14 mesh; see Chapter 4 for definition of mesh), thus determining the rod mill work index ...

Bond Rod Mill Grindability Test. Grinding Solutions can carry out Bond Rod Mill Work Index tests to determine the energy requirements for milling ore in a rod mill. The test requires a minimum of 20kg of -12.5mm material. Closing screen sizes typically range from 4.75mm to 212µm. Abrasion Index Test

Cleaning and Storing of Ball Mill Charge after the Bond Work Index Procedure is done: Add about 500 g of silica sand into the mill containing the ball charge. Seal the mill. Rotate for 20 revolutions to clean. Empty the mill charge and sand into the ball try once grinding is complete. Clean out the mill using a brush. Put the lid on the mill.

FIGURE 5: BOND ROD MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 35 WiRM (metric) The lack of fit observed relating the crushing Work Index was expected to carry over to the other Bond Work Indices. Figure 5 displays the plot of rod mill Work Index (Wi RM) versus UCS. These

Apr 27, 2016· rod milling, is fitted to a tumbling test, referred to as the Bond rod mill work index (WiRM, or RWi). The apparatus used to determine this work index was described in 1943 by Bond & Maxton and a slightly different apparatus was described by Bergstrom in 1985.

The Bond ball mill work index test 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 .

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 ...

At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill. The Rod Mill Work Index (RWI) is used for particle size determination in a size range from 25 mm down to 2.1 mm whereas Ball Mill Work Index (BWI) is used for the range from 2.1 mm down to 100 µm. Adjustment of grinding parameters:

Rod mills normally carry 35 to 65% rod charge by volume. The limits on charge level are (1) keeping the feed end trunnion open so that feed will get into the mill, and (2) keeping the rod charge low so rods will not work their way into discharge openings where they can cause rod tangling.

The Bond ball mill work index is one of the most commonly used grindability tests in mining, and is often referred to as the Bond work index.. The test is a 'locked-cycle' test where ground product is removed from test cycles and replaced by fresh feed.

Ball Mill Bond Work Index: WiB = 12.1 kWh/st Rod Mill Bond Work Index: WiR = 10.5 kWh/st Impact Bond Impact Index: WiI = 7.9 kWh/st SAG Power ... MEI Online - Bond Work Index An abreviated test that did not reach steady state as a Bond Work Index does would only be ... mill sizing etc.

Measuring ore grindability in rod mills. The Bond Rod Mill Work Index is a measure of the resistance of the material to grinding in a rod mill. It can be used to determine the grinding power required for a given throughput of material under rod mill grinding conditions. It is a 'locked cycle' test conducted in closed circuit with a laboratory ...

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 …

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.

The standard Bond Rod Mill Work Index test 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 standard Bond rod mill. A Bond rod mill is 0.305m by 0.610m, with wave liners (of a form described by Bond), which runs at 40rpm and tilts as described below.