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 'lockedcycle' test where ground product is removed from test cycles and replaced by fresh feed. The test much achieve a steadystate before completion.
Bond ball mill work index (BBMWI) test is a standard test used to measure the ball mill work, which is calculated in accordance with the procedure proposed by the Bond [21]. The BBMWI determines how much energy is needed to grind a sample of ore in a ball mill [22]. This measurement is expressed in kilowatthour per ton (kWh/t), which is the ...
operating work index) is also presented a product of for each simulation. For Greenfield design of an AG/SAGball mill circuit with JKSimMet, the additional power requirement in the ball mill(s) is determined with the Bond ball mill work index and the phantom cyclone technique. COMMINUTION Trusted Bench Scale and Pilot Scale
In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements of circuits containing: • AG and SAG mills. ... As a general rule Bond ball work index tests are recommended when SMC Tests® are carried out as this provides valuable additional information on the way that much ...
This Table of Ball Mill Bond Work Index of Minerals is a summary as tested on 'around the world sample'. You can find the SG of each mineral samples on the other table.
This paper examines potential relationships between UCS and Bond Work Index values (crushing, rod mill and ball mill). Data from 11 mines located around the world is analysed for correlations between UCS and various Wi values. Introduction Need to accurately predict future mine and mill production rates requires a knowledge of ore
The Bond work index, W i, is defined in a Bond ball mill on the samples of standard size − + 0 mm. In practice, it is possible to find materials of nonstandard size that are finer than 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 nonstandard size.
The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work index methodology ...
The Bond ball mill test is used to determine the socalled standard work index, which is defined as the specific energy consumption (in kWh/t) required to reduce a material from a notional ...
An SMC Test® and Bond ball mill work index test (with closing screen 150 μm) were performed on an ore sample with the following results: M i a = kWh t − 1 ; M i c = kWh − 1 ; M i h = kWh − 1 ; M i b = kWh t − 1 .
WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) WiRM Bond Rod Mill Test Work Index (kWh/t) WiSTD Standard Circuit Bond Work Index (expected or designed) used for circuit design. Specific energy requirement at ...
As such Bond ball mill work index alone is not an effective basis to estimate the comminution energy requirements for many of Newmonts operations. Figure 1 Newmont sites on the Bond intensity energy curve, comparing the BWi The position of the sites on the Bond operating work index (OWi) energy curve is presented in Figure 2. What is
BOND'S WORK INDEX: WHAT IT IS AND WHAT IT ISN'T *Alex Doll1 and Berge Simonian2 1Alex G Doll Consulting Ltd. PO Box 1236 Logan Lake, BC V0K 1W0 (*Corresponding author: a ) 2Centerra Gold Inc. Mount Milligan Mine 299 Victoria St, Suite 200 Prince George, BC V2L 5B8 Abstract
The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is timeconsuming (close to 5 hours ...
Research was performed to make an objective comparison of Bond Ball Mill Grindability Work Index results derived from using two commercial testing apparatus, from BICO and Sepor respectively, each ...
world. It shows that the ball mill work index is normally distributed with an average of and a median of kWh/t. bOnd rOd mill GrindAbility The Bond Rod Mill Grindability Test is performed similarly to the ball mill test. The feed sample is stagecrushed to ½" and the test is run under a circulating load. As in the ball mill ...
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 it is necessarily to provide a correction. The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis
The work index equation for a ball mill test was generated by Fred Bond to empirically predict the operating work index of an industrial ball mill (8 ft dia by 8 ft effective grinding length ...
Jack Levin published a paper in the Journal of the SAIMM in 1989 describing a way to use a Bond ball mill grindability test apparatus to grind materials when the feed was already finer than mm ...
The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index.
Over the years, alternative procedures to the Bond grindability test have been proposed aiming to avoid the need for the standard mill or to reduce and simplify the grinding procedure. Some of them use the standard mill, while others are based on a nonstandard mill or computation techniques.
Average grinding work index (Wi) by type of mate rial, according to Bond (see table ): The work index (Wi) expresses the kWh required to reduce a short ton of material from theoretically infinite feed size to 80 % passing a square screen opening of 100 microns. The work index values apply to ball mills grinding wet in closed circuit.
The ball mill work index is shown below. BM Wi (kWhr/st) = BM Wi (kWhr/mt) = Bond Ball Mill
The goal of this work is to create an equation to adjust a Bond ball mill work index from one P80 basis to another. The proposed model consists of two components, the variable coefficient that is ...
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.
An alternative mill ball charge is proposed that closely approximates Bond's original total ball mass, number of balls and ball surface area. Results of 30 Bond Work index tests of six pure materials (calcite, magnesite, labradorite (feldspar), quartz, andalusite and glass) using closing screen apertures (P 1 ) values of 500, 250, 125, 90 and ...
Standard Bond ball mill grindability tests and calibrated Mod Bonds, using a closing screen of 270 mesh (53 microns), classified most samples as medium to moderately hard and averaged kWh/t (Mod Bond only). The SPT lockedcycle high pressure indices (HPi) ranged from kWh/t to kWh/t averaging kWh/t.
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 mm, as required for the Bond Ball Mill Work Index test feed.
You need a twostage solution, first stage opencircuit mill and then second stage closedcircuit mill. First stage, will be broken into two parts as well, you use a Bond rod mill work index for the coarse component of the ore (+ mm) and the Bond ball mill work index for the fine component ( mm).
The ball mill grindability test is used for describing ore hardness and it is so widespread that the Bond Work Index generated from the test is often referred to as an ore characteristic. The ore resistance to grinding and energy consumption can be expressed using the work index and Bond's Third Theory.
The Bond rod mill and ball mill work indices are the most similar in size classes, both being fed material crushed to "relatively fine" sizes. Both test are also lockedcycle tumbling tests where the charge of ore in the mill is brought to a steady state over the duration of a test.
The Bond ball mill work index test has been used for ore hardness characterization for more than 80 years. Nevertheless, the test suffers from significant disadvantages when compared with other ...
The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is timeconsuming (close to 5...
A Bond laboratory ball mill work index test was conducted using a closing screen of 150 m which gave a P80 of 108 m. A calculation is required to be carried out to estimate the specific energy ...
For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding performance. Signature Plots. No general work index formula governing energy use over a range of conditions, like the Bond equation for intermediate grinding, has yet been found for the fine grinding regime. Instead, the work ...
© DZCrusher - كل الحقوق محفوظة
