In ball milling, the Bond ball mill work index can be used to determine specific energy at a range of feed and product sizes. The Bond top size ball formula can be used to estimate the media size required. No such standard formulas exist in fine grinding. Energy and media parameters must instead be determined in the laboratory for every new ...
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.
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 …
The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. The test requires a minimum of 10kg of sample that has been stage-crushed to passing size of <3.35 mm.
Insmart Bond Work Index Ball Mill, work index Mill
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.
The Bond grindability testing procedure has been standardized to obtain the same grindability values, i.e., Bond work index (BWi), on the same ore when tests are performed in different laboratories or by different operators. This is accomplished by the standardization of mill dimensions, tumbling speed, grinding-ball charge weight and distribution, sample charge …
µm. Note that—in order for no correction factor for ball mill product fineness to apply—the ball mill circuit P80 should be no less than approximately 70 µm (Bond, 1962). This Bond Efficiency determination should not be applied to cir-cuits with a P80 finer than approximately 70 µm without making qualifications. 3.
The work index expresses the resistance of the material to grinding. It represents the kilowatt hours per tonne required to reduce the material from theoretically infinite feed size to 80 passing 100μm (Wills and Napierpercent -Munn, 2006). Bond devised several methods for predicting ball-mill and rod-mill energy requirements and
Bond Index Ball Mill / Rod Mill BT 100 XL - RETSCH. The Bond Index conforming rod charge consists of: 6 rods of 125" diameter and 21" length 2 rods of 175" diameter and 21" length The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or …
plant ball mill's grinding efficiency (Fig. 1). The functional performance parameters "mill grinding rate through the size of ... 350 for wet overflow mills, etc. WI Bond test Work Index, kWh/short ton. SG Ore specific gravity. Cs Mill speed in percent of …
The grinding jar of the Bond Index Ball Mill measures 12″ x 12″ and has well-rounded corners. Module Rod Mill Minerals pre-crushed to < 12.50 mm and sieved Drillcore pre-crushed to < 12.50 mm and sieved Half a drillcore pre-crushed to < 12.50 mm and sieved The Bond Index conforming rod charge consists of: 6 rods of 1.25" diameter and 21" length
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. The simplified test method described in this paper is an alternative procedure to the ball mill grindability test.
Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes It is commonly known that one must run the Bond ball mill work index test such you pick a closing mesh to give a P80 close to desired grind size.
The FC Bond Mill was designed by F. C. Bond for use in determining the Bond Ball Mill Index, a measure of grindability and power required to mill various ores. FC Bond Mills are used in laboratories throughout the world. A copy of Fred C. Bond's Method of Crushing and Grinding for determination of the Bond Index is included with each mill.
The Bond Index conforming rod charge consists of: 6 rods of 1.25" diameter and 21" length. 2 rods of 1.75" diameter and 21" length. The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.
BBMWi: Bond Ball Mill Work Index C i: Crushing parameter COV: Coefficient of variation DWi: Drop Weight Index DWT: Drop Weight Test E: Young´s modulus of Elasticity Ecs: Specific Comminution Energy E is: Specific input energy F 80: 80% of the feed passing
The Bond Ball Mill Work Index is a measure of the resistance of the material to grinding in a ball mill. It can be used to determine the grinding power required for a given throughput of material under ball mill grinding conditions. It is a 'locked cycle' test conducted in closed circuit with a laboratory screen.
standard Bond crushing, and rod mill work indices, abrasion indices and by Dawson for Bond Ball Mill Work Index tests using crushed feed, and Standard Autogenous Grinding Design (SAGDesign) Tests, patented by Outokumpu. (See reference 8 below). The comparison of these results gives context to how the various measurements relate to each
We require a minimum of the feed size (F80), product size (P80), Bond Ball Mill Work Index (kWh/mt), feed rate (tons/hr) and Ore Specific Gravity (t/m). However, we would prefer to have more detail so that a proper mill sizing assessment can be completed. Please complete the attached form with as much detail as possible.
Ball Mill Wio, BWio 8.6 Circuit Wio, OWio 14.6 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 ...
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 kilowatt-hour per ton (kWh/t), which is the ...
Bond ball mill and grind for an arbitrary number of mill revolutions (N 1 = 50, 100 or 150 revolutions). After grinding, screen the sample on the comparative sieve and determine
Bond/Barratt Specific Energy Consumption SABC Model. This is a SAG or AG mill plus ball mill model that estimates the overall circuit specific energy consumption using the classical Bond work index equation for multi-stage crushing and single-stage ball milling (E ssbm) including Rowland efficiency factors.The circuit E total is equal to the E ssbm plus an inefficiency factor …
Bond's work index which is defined as the resistance of the material to grinding. The standard equation used by them for the ball mill work index (Bond work index) is as follows. / F 80 80 0.23 0.82 /10 44.5 1.1 GP W i bg i (4)
80 sizes typically reached by conventional ball milling. The delineating size between coarse and fine grinding is 750 µm. SMC test results are used to determine the Drop Weight Index (DWi) and the coarse ore grinding index (M ia). Test data from the Bond ball mill work index test is used to calculate the fine grinding index (M ib). The M ia and M
BALL MILLS, ROD MILLS & BOND INDEX MILLS Labtech Essa manufacture a range of metallurgical laboratory sized ball and rod mills to suit most applications. Included in the range is a Bond index mill which has specific application in establishing the grindability of ores (see sheet 2 of this data sheet) The ball and the rod mill are of essentially ...
For overflow ball mills, the charge should not exceed 45% of the mill volume . For grate discharge mills, the charge should occupy about 50% of the mill volume . Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge, He, and the radius of the mill, R, i.e.,
Essa® Bond Test-Work Equipment. Internationally accepted mineral metallurgical standard test procedures to determine the physical properties of ores include the Bond ball mill work index and the Bond rod mill work index. These are empirical indices determined by close circuit grindability tests developed by F.C.Bond in the mid 1930's.
SAG grindability index; Bond ball mill work index; Required parameters. F 80, µm is the 80% passing size of the fresh feed to the circuit (expected to be a Bond-compatible size distribution). P 80, µm is the 80% passing size of the circuit product (expected to be …
The paper presents the relative errors of the obtained value from the actual Bond Ball Mill Index, the average working hours for the testing procedure and necessary equipment. Keywords: Ball Mill Work Index, Bond Index, Grindability, Ball grinding, Ore testing, Grinding energy consumption, Physical and mechanical ore properties
SMC Data Processing. The results from conducting the SMC Test® are used to determine the drop-weight index (DWi) which is a measure of the strength of the rock as well as the comminution indices Mia, Mih and Mic. In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements of ...
This video was put together by Joshua Wright and Aldo Vasquerizo as a supplemental lecture for University of Nevada Reno.If you have any questions, need advi...
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 feed.
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. • Ball mills • Rod mills • Crushers • High Pressure Grinding Rolls (HPGR)
micrometers in size. 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 test is performed on a raw material approximately weighing 10 kg, which coarseness is -3.327 mm.
The laboratory procedure for running a Bond ball mill work index test requires that the operator choose a closing screen sieve size. The instruction is to choose a …