Chapter 3 - Particle Technology Size Reduction 3.2.2 Bond crushing law and work index. The work required to form particles of size Dp from very large feed is proportional to the square root of the surface-to-volume ratio of the product, spvp.
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 100 passing size of 3.35 mm.
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 power.
The Bond work index determination according to the standard Bonds test is done on all these samples with compara-tive sieve size of 74, 105 and 150 microns. The Bond Work Index is calculated using the formula Bond, 1961 1 where W i Bond work index kWht P c test sieve mesh size m
The Bond Standard Circuit Work Index used for circuit design specific energy requirement, at the drive pinions, which is equal to the ores combined laboratory test Work Index. These are equal tothe expected or design Work Index of the Bond Standard Circuit, which is
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 Bonds Third Theory of Comminution to calculate net power requirements when sizing ball mills. Various correction factors may have to be applied.
occurs. The work input, assuming no change in work index, is .194 kwhton. For a mine crushing 50 million tons per year, a reduction of 1.8 million kilowatt-hours, or about 125,000 per year is realized. The second possibility is a decrease in Wi. There is evidence that work index bears a
The mineral processing research institute has a sample crushing room and can conduct rock ore identification, Bond grinding work index test, intelligent laser particle size detection and so on.
ability to work harden while crushing, which extends its wear life dramatically. u Liners work hardens by compressive forces and at any given time the work hardened face is only about 2-3mm. The speed at which the liner work hardens increases as the percentage manganese content increases so12-14 work hardens slowest amp 20-24 ...
Jan 01, 2016 Currently, the dimensions of the largest Blake-type jaw crusher in use are 1600 mm 2514 mm with motor ratings of 250300 kW. Crushers of this size are manufactured by Locomo, Nordberg Metso and others. The Metso crusher is the C 200 series having dimensions 1600 mm 2000 mm driven by 400 kW motors. Table 4.1.
Sep 16, 2020 mineral particles was higher than 1000. Occurrence of a given mineral was counted when it has appeared in the nod grid. Liberated ore minerals were counted separately, and separately in intergrowths. It was possible to distinguish three types of mineral intergrowths with carbonates, quartz and clay minerals. Bond work index W
Mar 20, 2013 A typical recirculation load for an attrition ball mill processing limestone with a bond work index of 10 and a feed particle size of 14x 0is between 140 to 150. Calcium Carbonate Crushing Grading Production Line Process
A refining process that uses electricity to collect mineral particles. An analysis of ore to determine its chemical content. A form of pyrometallurgy involving extremely high temperatures. The grindability of minerals is measured in Bond flux density. Scoville scale of attraction. Bond work index. Mohs scale of mineral hardness.
Basics in Minerals Processing BASICS IN MINERAL PROCESSING. 354 Pages. Basics in Minerals Processing BASICS IN MINERAL PROCESSING. Simphiwe Nzuza. Download PDF. Download Full PDF Package. This paper. A short summary of this paper. 24
Using the Bond hypothesis the Vibratory Work Indexes were determined for the tested materials. Their values are higher than limestone and diabase Work Indexes available in the known literatures. The explanation may be greater amount of energy transferred to the material during vibratory crushing, which results in much higher efficiency of the ...
FIGURE 1 BOND CRUSHING WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS, MPa 10 20 30 40 50 WiC metric The scatter of the points in Figure 1 indicates no correlation between crushing work index and UCS.
A clear definition of the required crushing capacities and the desired product quality can be precisely determined by using the Bond Index test methods. Using the Bond Index test procedures it is possible to calculate crushing abrasion behavior of mineral samples. This knowledge is essential to define the required ball mill layout and ...
Rittingers theory and law of the energy expended in crushing of .. of the weaker bonds, and the particles thus formed are free to resume their. determination of the bonds work index of baban Keywords Grindability, comminution, energy, mineral, comparative The Bond work index Wi is used as a measure of grindability of an ore Deniz, 2003.
Handbook of Crushing Glossary of Terms Angle of Nip The angle formed between the moving surface of a crusher roll or jaw plate and the stationary plate surface at which point the material will be pinched. Angle varies with machine size and material lump size. Bond Work Index BWI
Tests range from industry standards, such as Bond Work Index Testing, to cutting-edge techniques such as pulp chemistry monitoring, to help optimise comminution circuits. We are also a Metso accredited laboratory for fine grinding. We have comminution equipment including ball mills, rod mills and a range of crushing equipment.
Jul 02, 2021 Nov 26, 2012 Bonds work index E1 is the energy required for grinding per unit mass for sand Bonds work index E1 is the energy required for grinding per unit mass for sand Bonds . Ammtec Bond rod mill work index, Bond ball mill work index and Bond abrasion index are carried out on sub samples cut from the main tumbling test sample.
Mic Ore work index in crusher circuits kWht Mih Ore work index in HPGR circuits kWht P100 100 passing size or closing screen aperture m P80 80 passing size of the circuit product m SABC Semi-Autogenous-Ball-Milling-Crushing SAG Semi-Autogenous Grinding x1x3 Generic terms for P80 W Specific energy work input kWht
May 18, 2021 The composites from the identical unsorted sample of quarter drill core will be subjected to SMC tests for comminution, Bond Work Index tests, bulk mineral content analysis, and
The Bond low-energy impact crushing work index more informally, the Bond crushing work index is not as common as the Bond ball mill work index, and it is a notoriously noisy test.. The test is a per-specimen test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus.
where Wi is the Bond Work Index, again in energy per unit mass terms. The index is defined as the energy required to crush from infinite size down to 100 m, hence the 10 inside the brackets. Bonds Work Index values, in kWh per short ton i.e. 2000 lbs or 907 kg, roughly follow the Mohs scale of hardness, see Table 11.1.
energy impact work index a.k.a. crushing work index is conducted only on coarse specimens placed one at a time in the testing apparatus. With respect to the crushing work index test, F.C. Bond 1946 specifies that In the standard method of testing only broken pieces that
Jan 01, 2016 Mineral Work Index W i P 80 Abrasion Index A i ... Bonds crushing work index of gypsum. 3.4. A sample of granite passing a 7.5 cm square opening screen was suspended in a Bonds pendulum test. The length of the pendulum was 413 mm and the mass of hammers is 13.6 kg each. The sample was completely crushed when the initial position of ...
Grindability. by Ames. Ore grindabihty refers to the ease with which materials can be comminuted and data from grindability tests are used to evaluate crushing and grinding efficiency.Probably the most widely used parameter to measure ore grindability is the Bond work index W The work index, Wi, is calculated kWh per ton applied in reducing ...
Mineral Processing - Crushing - Plant design, construction, operation and optimisation ... GRINDABILITY TESTS Bond Rod mill work Index The rod mill work Index is also normally distributed with and average and median of 14.8kWht It is common to observe difference between the ball and rod mill caused by variation in ore hardness The ...
coal marl bond work index increased to 23, 21 and 12,respectively and HGI raised to 46, 24 and 14. Bond work index of porous coal did not change. The optimum crushing and grinding method for clean coal production was discussed and designed. The Standard Bond Grindability Test The most widely known measure of grindability
Sep 01, 2017 In the next step, the performance of rock fragments in comminution processes was examined by conducting some crushing and grinding experiments. Results showed that the blasting process can reduce the Bond work index of fragments as
The most widely used parameter to measure ore hardness is the Bond work index Wi. Calculations involving Bonds work index are generally divided into steps with a different Wi determination for each size class. The low energy crushing work index laboratory test is conducted on ore specimens larger than 50 mm, determining the crushing work index Wi C, CWi or IWi impact work index.
49 rows Jun 19, 2015 This Table of Ball Mill Bond Work Index of Minerals is a summary as tested on around the ...
Abstract 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 comminution plants designing. Determining the Bond work index value
The crushing energy in mineral processing industry is usually determined by empirical Bond index, regardless of the mechanical properties of a rock. Although several attempts have been made to obtain the comminution energy based on theoretical approaches, it would be beneficial to examine this relation based on physical concept.