size reduction - SlideShare
1. Bond's work index is the work required to reduce unit weight from a theoretical infinite size to 80% passing 100µm. 2. This theory is useful for rough mill sizing. 3. The work index is useful for comparing efficiency of milling operations 23. Kick's Theory 24. For compression of large particles kick's theory is useful. 25.
Mineral Comminution fine / ultrafine grinding
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 accredited laboratory for fine grinding. We have comminution equipment including ball mills, rod mills and a range of crushing equipment.
Ball Mill Design/Power Calculation
A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work index of 15 and a size distribution of 80% passing ¼ inch (6350 microns).
Comminution testing - JKTech - University of Queensland
An improved method using less mass compared to the Bond Ball Mill Work Index test. The JK Bond Ball Mill (JKBBM) test, is a locked cycle grindability test conducted using a standard laboratory Bond Ball Mill with the same steel ball charge and material feed size ( passing 3.35 mm) as the Bond Ball Mill Work Index test.
Bond Ball Mill Work Index | GTEK
Bond Ball Mill Work Index. GTEK Bond Ball Mill Work Index is used for determine the grindability of materials, and help to choose the most suitable type and model of grinding equipment. Ask For Quote Donwload. Find more details in the options below. Photo.
MODELING OF SIZE REDUCTION, PARTICLE SIZE ANALYSIS …
Model parameters like degree of uniformity in size and statistical average diameter of ground products, mean sizes of ground particles, Bond's work index, specific energy consumption for grinding, and flow characteristics indicate cinnamon and coriander are suitable for grinding with hammer mill while turmeric is suitable for
Operating work index is not the specific energy consumption
However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameter-Kwhr/m3-, so it is more complex than just specific energy consumption ...
Optimization and Performance of Grinding Circuits: The ...
were conducted; standard Bond tests to determine ore grindability and work indices, batch grinding tests to determine parameters for breakage and selection functions, and standard ball mill tests for mineral liberation characterization by an automated mineral liberation analyzer (MLA).The tests were conducted in a size range from 0.063 to 2 mm.
Milling Circuit Calculations | Request PDF
The Bond work index is one of the most useful and interesting parameters used in designing grinding equipment. However, it must be obtained under restrained conditions, especially in …
Particle-size reduction - Chemical Engineering | Page 1
d p = Particle size of product, as defined as the sieve size through which 80% of the product would pass, µm. Bond's work index, by definition, is the energy required per unit mass to reduce the particle size from infinity to 100 µm. It is independent of particle size, but does depend on the machine and mechanism of size reduction.
Bond Work Index - Determination of the Bond Work Index of ...
[2] "The Bond work index refers to the measure of the material's hardness or resistance to crushing and grinding, and is numerically expressed as the kilowatt hours per short ton required to reduce the material from theoretically infinite feed size to 80% passing 100 µ.m." [2] It is calculated using the equation below: W i = 4.45 P i 0 ...
Bond F C Crushing And Grinding Calculations Allis Chalmers ...
Crushing And Grinding Calculations Mining. F. C. Bond, Crushing and Grinding Calculations, F. C. Bond, Crushing and Grinding Calculations, British Chemical Engineering, Vol. 6, 1961, pp. 378-385. has been cited by the following article TITLE A New Approach to the Calculation of Work Index and the Potential Energy of a Particulate Material.
CORRELATION BETWEEN BOND WORK INDEX AND …
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
Breakthrough in Clinker Grinding
are smaller than the characteristic size). Bond's work is notable because of its widespread adoption in the design of most modern industrial grinding circuits. Bond developed a work index function that he suggested was a measure of the crack length needed to …
Bond Work Index Procedure and Method
The Bond grindability was calculated to be 1.21 g net undersize/revolution by averaging the results from the last 3 runs on the Bond Mill. The grindability is defined as the ease at which a mineral particle is reduced to a predetermined size …
Comminution testing to reduce risk | FL
The FL P150 High-Pressure Grinding Roll (HPGR) sizing machine is used for all initial HPGR lab-scale test work. The pilot-scale crusher is designed to process ore in the identical manner of an industrial unit, as it employs the exact same breaking mechanism.
Investigation into the applicability of Bond Work Index ...
The Bond Work Index (BWI or W i) is defined as the calculated specific energy (kW h/t) applied in reducing material of infinite particle size to 80% passing 100 μm . The higher the value for W i, the more energy is required to grind a material in a ball mill [10], [26] .
Unit Operations in Food Processing - R. L. Earle
Grinding and cutting. Energy Used in Grinding Kick's Law Rittinger's Law Bond's Law Work Index New Surface Formed by Grinding shape factors specific surface Grinding equipment. Crushers Hammer mills Fixed-head mills Plate mills
how do i calculate energy balance of a grinding mill
Know more. What exactly is 'Work Index' and how can I make use of it - Metcom, 'Work Index' is to measuring energy in size reduction what the 'meter' is to, For example, a grinding circuit is processing 450 t/h (of dry feed) with a mill drawing, Then WIo, the "Operating Work Index" of this circuit, is calculated as follows:, ball mill ...
Multi-Compartment Rod/Ball Mill Evaluation on Bauxite ...
Traditionally, the sizing of mills for the minerals industry is based on the Bond Work Index (BWI) [1]. The standard Bond test is performed in a mill with predefined characteristics and in a dry process, with subsequent application of correction factors proposed by Bond and Rowland for equipment sizing [2]. Bauxite grinding typically has ...
Characteristics of Mae Moh lignite: Hardgrove grindability ...
pulverized. However, this index can not be used to size a pulverizer and mill power directly. Only the specific energy, mill power over capacity, is a main parameter for mill sizing. Specifically, the Bond work index is suitable for utilization in many industrial grinding processes (Rhodes, 1998). *Corresponding author.
Mechanism of size reduction - SlideShare
Bond's law Bond terms Ei the work index, and expresses it as the amount of energy required to reduce unit mass of material from an infinite particle size to a size L2 of 100 μm, that is q =∞. The size of material is taken as the size of the square hole through which 80 per cent of the material will pass. 31.
Grinding Machining Process : Complete Notes - mech4study
The self-sharpening behaviour of grinding wheel is a necessary part of the grinding machine and the selection of the grinding wheel depends on the work material. The bond between the abrasives is not too strong if the bonds retain the abrasives strongly then it will not allow the abrasive to be pulled out after wear.
C O N S U L T I N G L T D TECHNICAL MEMORANDUM
The Bond Work Index Before the 1950's the grinding industry had no ability to scale-up grinding results from laboratory to industrial mill sizes, or to reliably estimate the specific energy when either a feed or product size changed.
SAGMILLING .:. Articles
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.
Metallurgical Engineering – Jet Rom Solution
The Bond Ball Mill Work Index can be used in the design calculations and simulations of a new grinding circuit. 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 10 kg of – 3.35 mm.
GMSG GUIDELINE: DETERMINING THE BOND …
Use of the Bond Work Index to size industrial grinding equipment was widely known. Bond also described its application for measuring grinding circuit efficiency. Bond Work Index efficiency has been widely used by industry, but until now without concise standard methods, or a formal guideline, for doing so. The Bond Efficiency SubCommittee of -
Size Reduction - an overview | ScienceDirect Topics
Size reduction by mechanical actions, often called shredding or grinding, has been reported 14,15,16,17,18,19,20 and many types of equipment are commercially available for processing textile and carpet waste. 21, 22 In a typical process, the feedstock is cut by a rotary drum fitted with hardened blades against a feeding bed, and the cut ...
THE BOND WORK INDEX OF LIMESTONE AND ANDESITE …
Bond work index value of these components mixtures is greater than the Bond work in-dex of harder components, clinker. Oner (2000) have conducted a research of clinker and blast furnace slag mixture Bond Work Index in different mass propor-tions. He found out that these values are always lower than the Bond Index obtained
Energy Use of Fine Grinding in Mineral Processing ...
where W is the specific grinding energy (kWh/t), W i is the Bond ball mill work index (kWh/t), F80 is the feed 80 pct passing size (μm), and P80 is the product 80 pct passing size (μm). It can be seen that in the regime in which the Bond equation is valid, energy use increases exponentially as product size decreases with constant feed size ...
Table of Bond Work Index by Minerals
Source 1: Table of materials reported by Fred Bond Source 2: Outokumpu, The science of comminution Source 3: Equipment and pipelines Source 4: Tenova Bateman mills (AG/SAG, Rod, Ball Mills) Source 5: Doering international Source 6: SME handbook of mineral processing, N.L Weiss Editor, NY 1985. Bond Work Index Tester
Bond Work Index (Energy equation) - Grinding ...
The Bond Work Index is a factor that measures the energy consumed in size reduction operation of the ore. The Bond's Work Index equation is: W=WI* (10/√P80 -10/√F80) where W= the energy input (Work input) per ton, kwh/metric ton WI= Work Index= specific energy per ton, kwh/metric ton (characterizes the ore)
CONTRIBUTION TO DETERMINATION OF COAL GRINDABILITY …
of Hardgrove Grindability Index (HGI) values to Bond Work Index (Wi). Paper also provides information on ... specification and is significant also for the design of capacity of particularization equipment and grinding ... sample of grain size below 4.75 mm is ground and subsequently screened for preparation of analytical sample of
Bond Work Index - an overview | ScienceDirect Topics
The Bond work index is not solely a material constant but is influenced by the grinding conditions. For example, the finer the grind size desired, the higher is the kWh/t required to grind to that size. Magdalinovic [38] measured the Bond work index of three ore types using different test screen sizes.
GRINDING MACHINES - Carnegie Mellon University
work. Grinding machines have some special safety precautions ... well as the motor rating determine the wheel size capacity of the machine. Suitable wheel guards and tool rests are ... The most common bonds used in grinding wheels …