Procedure for determination of ball Bond work index in the commercial operations …
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, …
the work index depending on the grind size. In this way, work index values are usually obtained for some specific grind size that characterizes the grinding operation to design or under evaluation. This study was carried out in a standard bond ball mill 305 mm x 305 mm size in mineral processing laboratory, in the mining engineering department ...
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. Mill operators have long used operating ...
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, industrial minerals and rocks). These work indexes can be used for the determination of tumbling mills (rod, ball mills ...
The Bond ball work index is widely used in the field of minerals processing as an indicator of ore grindability. The work index is determined by means of a locked-cycle test procedure that typically requires seven to eight cycles to stabilise at a …
Here is the old Allis-Chalmers Bond Work Index Grindability Test Procedure. The standard feed is prepared by stage crushing to all passing a 6 mesh sieve, but finer feed can be used when necessary. It is screen analyzed and packed by shaking in a 1000-cc graduated cylinder, and the weight of 700 cc is placed in the mill and ground dry at 250 ...
Determination of Bond Index of Wasagu Manganese. ABSTRACT. the grinding power required for a given throughput of material under ball mill grinding consitions JKTech Pty, A Bond Ball Mill Work Index test may be required for the design of a, sample of ore that is typical of the proposed feed to the plant.
The results suggest that the Starlight primary (fresh) mineralisation has a Bond Ball Work Index value of 11.2-13.1 kWh/t lower than many primary Yilgarn gold …
A Bond ball mill work index is then performed on the mill product for the design of SAG-ball mill circuits. This is important because it was found that there was a 1–1.5 kWh/t higher ball mill work index if the –3.35 mm ball mill test feed size is obtained by SAG mill grinding compared with crushing.
A quick procedure with two grinding cycles for the determination of the Bond. work index approximate value is exactly the same as in the first two …
measured, and the Bond work index (BWI) is calculated as follows: Where P1 is the aperture of the closing screen in microns, and F 80 and P 80 are the 80% passing sizes of the test feed and product. The world relies widely on the ball mill work index for the design and analysis of ball mill circuits, even those that treat
(U.S. coal, metals, and minerals mining, 2007) 0.6 Table II. Comminution Equipment, Size Classes, and Grinding Mechanisms Grinding Level Equipment ''Typical'' P80 (lm) Dominant Breakage Mechanism* Coarse AG/SAG mill 500 to 10,000 impact+abrasion+attrition Intermediate ball mill 40 to 400 impact+attrition tower mill 40 to 400 attrition
FIGURE 6: BOND BALL MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 WiBM (metric) Figure 6 displays the plot of ball mill Work Index (Wi BM) versus UCS. Still no relationship is observed.
A method of grinding a mineral-containing ore, which includes grinding the mineral-containing ore in a primary milling process and thereafter fine grinding the mineral-containing ore in a secondary ball-mill. A composite grinding medium comprising a mixture of steel balls and pebbles is used in the secondary ball-mill. The pebbles have an average size which is …
The Bond work index can be determined by many ways, some of them are as follows: with the traditional standard method in a (1) Bond-ball mill or in a (2) Hardgrove mill with the conversion of the Hardgrove method's result to Bond work index by an empirical formula, (3) with the more work-saving Karra algorithm (compared to the standard Bond ...
The actual minerals are rarely used, particularly diamond, as it is expensive to procure. For instance, a fingernail is often used to represent hardness scale 2.5 and a steel file for 6.5. The testing process involves starting at the soft end of the scale and working through until one of the minerals/materials leaves a permanent indentation.
B - Bonds On/Off Help on Above Escobar C, Cid-Dresdner H, Kittl P, Dumler I, American Mineralogist, 56 (1971) p.489-498, The relation between light wolframite and common wolframite, sample: light wolframite
The work index, w, is a parameter which presents the ore grindability and is used in Bond fo rmula. The required energy to break and reduced or es size is …
Testwork: Bond abrasion index SAGMILLING. Test name: Bond Abrasion Index Abbreviation Alternate Forms Ai Typical F 80 size Typical P 80 size 19 000 µm n/a Models: Steel wear calculation The Bond Abrasion Index is a measure of how readily a rock sample will wear away steel that comes into contact with it.
A Bond ball work index test for a composite prepared from the remaining sample mass of four of the six original samples was calculated at about 20 kWhr/tonne. Gravity recovery and screened metallic analyses indicate that there was likely not a presence of coarse "nugget" gold, and that a gravity recovery circuit would not likely be included ...
The work index (Wi) is calculated in a laboratory-scale ball mill with Bond equation. The Bond work index has been widely used in designing full-scale mills but the Bond test is rather complex, lengthy susceptible to procedural errors and this is why attempts have been made to abbreviate and simplify Bond test procedure ( Weiss, 1985 ). 2.
Observed reductions in the Bond ball work index have typically been in the range 0–10%. The equations used in this paper makes no specific allowance for the influence of micro-cracking. However, if HPGR products are available which can be used to conduct Bond ball work index tests on, then M ib values obtained from such tests can be used in Eq. .
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 …
From an ore hardness and comminution perspective, the majority of South Australian magnetite ores have a rock strength classified as soft to medium with Bond crushing work index (CWi) values typically 10–20 kWh/t, abrasion index (Ai) values 0.2–0.6 (majority <0.5) and Bond ball mill work index (BWi) values 11–19 kWh/t.
Average annual production of 303,000 ounces of gold over a 10.3 year life of mine within proposed pit shell; ... Bond Rod Work …
There were sulphide minerals present with sulphur grades in the deeper samples ranging from 0.62% as high as 3.3% but they did not present refractory recovery issues in the samples tested. Other potentially deleterious elements such as mercury, tellurium ... • Bond Ball Mill Work Index (BWi) – average 14.6 kWh/t (medium to hard)
Bond procedure is followed, the Bond work index is relatively consistent anywhere in the world, and should be very repeatable [4]. Figure 1 shows a histogram of Bond ball mill work index frequency from A.R. MacPherson Consultants (ARMC). This database covers a fraction of all the tests performed by ARMC over the years and around the world.
Abstract. 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 ball milling. This happens after 7–10 grinding cycles, which shows that the procedure is a lengthy and complex one and is therefore ...
This ball mill is typically designed to grind mineral ores and other materials with different hardness, and it is widely used in different fields, such as ore dressing, building material field, chemical industry, etc. Due to the difference of its slurry discharging method, it is divided to two types: grid type ball mill and overflow type ball mill.
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.
Table of Bond Work Index by Minerals. Mar 19,, 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, Basalt, 189, 171, 188, 190, 190, Concentrator Manuals/Procedures Crushing & Screening Dewatering Equipment Feeders.
published his method of energy calculation with an index called Bond work index (Bond 1961). In the 1970s, the population balance or selection and breakage function model was at the forefront of research (Fuerstenau et al. 1973). A number of advancements were made in the application of this model to ball mill grinding.
Gangue minerals include dominantly plagioclase and quartz along with sericite/muscovite, K-feldspar, and carbonates. Comminution: Bond Ball Mill Work Index (BWI) testing was performed on nine samples. The indices varied from 16.9 to 20.6 kWh/t, with an average of 18.6 kWh/t.
Table 4 shows the Bond work indices for some minerals and industrial materials from [25]. Note that the real circuit mills present work indices greater than those in laboratory tests, in a typical ...
Notes: Indicated Mineral Resources and Inferred Mineral Resources are reported in accordance with NI 43-101 with an effective date of the 12 th of August 2021, for the Koné deposit within the KGP.; The updated MRE is reported on a basis and is constrained within an optimal pit shell generated at a gold price of US$1,500/ounce.
The work performed included analysis of operating performance data from 49 mills and included extensive determinations of the Bond Abrasion Index for different ore types. For an improved understanding, the wear rate constant is directly related to the grinding media consumption rate expressed in grams of steel per kWh drawn by the mill, using ...
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial ...
Bond impact crushability work index (CWi) ( Bond, 1963) results reported for iron ores vary from hard iron ore (17.7 kWh/t) to medium hardness iron ore (11.3 kWh/t) and friable iron ore (6.3 kWh/t) ( Table 2.11; Clout et al., 2007 ).
