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 circuits with a P80 finer than approximately 70 µm without making qualifications. 3. Calculate the circuit ...
WhatsApp: +86 18838072829
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.
WhatsApp: +86 18838072829
The formula for calculating passing reduction ratio: P r = F80 / P80. Where: P r = Passing Reduction Ratio. F 80 = 80% Passing Size of Feed. P 80 = 80% Passing Size of Product. Let's solve an example; Find the passing reduction ratio when the passing size of feed is 21 and the passing size of product is 3.
WhatsApp: +86 18838072829
1. Reference ore Run a series of work index tests on a reference ore, as was done by Josefin. Then compute the specific energy consumption E for each test using Bond's Equation. Plot this specific...
WhatsApp: +86 18838072829
For a great presentation on How to Interpret Particle Size Distribution Data D50 D80 D90 and D10 you need to see https:// ...
WhatsApp: +86 18838072829
Defining P50 and P80 2 UNCLASSIFIED Defining P50 / P80 P50 and P80 refer to a confidence level regarding the probability of the cost not being exceeded, and does not indicate a quantum of cost or proximity to the actual cost realised. That is, P80 is not a cost plus/minus 20% but instead it is a cost that will not be exceeded 80% of the time.
WhatsApp: +86 18838072829
P = size in microns of the screen opening which 80% of the product will pass F = size in microns of the screen opening which 80% of the feed will pass When the above equation is used, the following points should be borne in mind: The values of P and F must be based on materials having a natural particle size distribution.
WhatsApp: +86 18838072829
Do you need a quick estimation of a ball mill's capacity or a simple method to estimate how much can a ball mill of a given size (diameter/lenght) grind for tonnage a product P80 size? Use these 2 tables to get you close. No BWi Bond Work Index required here BUT be aware it is only a crude approximation for "most soft ores" from F80 1 cm ...
WhatsApp: +86 18838072829
How to Calculate Charge Volume in Ball or Rod Mill | .. To calculate grinding media charge for continuous type ball mill, M = x D2 x L Example ..
WhatsApp: +86 18838072829
V — Effective volume of ball mill, m3; G2 — Material less than in product accounts for the percentage of total material, %; G1 — Material less than in ore feeding accounts for in the percentage of the total material, %; q'm — Unit productivity calculated according to the new generation grade (), t/(). The values of q'm are determined by ...
WhatsApp: +86 18838072829
As a review, the Functional Performance Equation, well documented and industrially validated (McIvor 2006, Bartholomew 2014), is shown below: QQ = 䝂ꈪMM × 㻨誧CC㻨誨 × GG × 䝂ꈪ GG Where: = metric tonnes per hour of new fines (
I'm designing a ball mill circuit to grind the crushed gold ore from F80 to P80 130 microns, simulation showed if we use one ball mill it would be 3m x with 800hp motor, and if I use 2 ball mills with same power then each would be x and 420hp, to split the power equally between 2 ball mills (first mill open circuit and secon...
WhatsApp: +86 18838072829
INTRODUCTION The energy consumption for grinding, according to Bond (1961), is deter mined by the formula: / 10 10 (I) The work index is determined by grinding experiments carried out in a labo ratory Bond ball mill. Based on the results of grinding experiments, numerical values of the work index Wi are calculated according to the formula ...
WhatsApp: +86 18838072829
The bottom parameters used in ball milling design (power calculations), rod mill or any tumbling mill page is; material to be ground, property, Bond Employment Card, bulk density, specific density, wish mill tonnage capacity DTPH, operates % stables or pulp density, feed extent as F80 and maximum 'chunk size', product size as P80 and maximum and ending the class of circuitry open/closed ...
WhatsApp: +86 18838072829
6. Product P80 of any intermediate crushing circuits treating primary crusher product (µm) 7. Product P80 of any intermediate HPGR circuit ahead of the tumbling mill stage(s) (µm) 8. Product P80 of the tumbling mill stage(s) (µm) •If there are multiple stages of grinding (, SAG milling followed by ball milling), only the P80 of the
WhatsApp: +86 18838072829
circuit P80 target size) material in the ball mill. It can be measured and then increased through pump and cyclone adjustments. By so transferring the application of ball mill power from fine (minus P80 product size) to coarse material, circuit efficiency is increased and overgrinding is decreased. The other factor that determines overall
WhatsApp: +86 18838072829
Technical Information. Information about sample size, calibration, precision and accuracy. The SMC Test® is the most widelyused comminution test in the world for AG SAG Mills, HPGRs and Crushers. The SMC Test® was developed to provide a range of useful comminution parameters through highly controlled breakage of rock samples.
WhatsApp: +86 18838072829
Gpb = the net screen undersize product per revolution in the laboratory ball mill (g/rev) P80 = 80% passing size of the closing screen undersize (µm) F80 = 80% passing size of the fresh feed (µm) f P 80 = + P 80 / f F 80 = + F 80 / . A worked example is given in Appendix A.
WhatsApp: +86 18838072829
One can argue the f50 is a more realistic value since balls wear and the average ball size might be closer to half the maximum. Then the multiple would be closer to 13 times the maximum particle size fed to the ball mill. A f80 = 6 mm would need a ball size of 75 mm. An empirical model from "Emerging Trends in Mineral Processing", 2005, is ...
WhatsApp: +86 18838072829
Therefore, a 350hp motor is required and this in turn indicates that an 812 (8′ x 12′) Rod Mill is required. In the same way Fig. 3 indicates that an 800hp motor and a 101/214 or ′ by 14′ Ball Mill is required. Following is a condensed tabulation of the above selections. Sizing a Ball or Rod Mill
WhatsApp: +86 18838072829
Optimum ball charge in a SAG mill is a function of many factors. Some are discussed below. For a SAB or SABC circuit. In general, the higher the ball charge the higher the throughput (and fine feed helps as well). Of course, you need a bigger ball mill. But, high ball loads mean higher ball consumption in the circuit.
WhatsApp: +86 18838072829
Bond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond's Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closedcircuit dry grindability test performed in a standard rod mill.
WhatsApp: +86 18838072829
Example Select (a) the size and (b) number of cyclones for a ball mill circuit for the following conditions: • Target overflow particle size is 80% passing 90 µm (, P 80 =90 µm).. The pressure drop across the cyclone is 50 kPa.. Slurry feed rate to the cyclone is 1,000 m 3 h −1.. Slurry is 28% by volume of solids specific gravity (55% solids by weight).
WhatsApp: +86 18838072829
Contribute to naicha22/2022 development by creating an account on GitHub.
WhatsApp: +86 18838072829
I'm interested to know when sizing a new ball mill, as to why recirculating load has no effect on the power calculation, although it will have effect on volumetric capacity naturally. ... The test provides the energy required to reduce a known mass of material from a F80 to a proposed P80 as stated above, nominally 106um (though specific ...
WhatsApp: +86 18838072829
Bond ball mill test procedure were carried out on crushed ( mm / 6 mesh) material at different screen closing sizes (300 µm, 212 µm, 150 µm, 106 µm, and 75 µm). The screening process was conducted in four sets of 12inch diameter screens for sufficient amount of time to avoid too much materials fed into the screen at one time.
WhatsApp: +86 18838072829
The approximate horsepower HP of a mill can be calculated from the following equation: HP = (W) (C) (Sin a) (2π) (N)/ 33000. where: W = weight of charge. C = distance of centre of gravity or ...
WhatsApp: +86 18838072829
Evolution of the ball grinding charge distributions proposed by Bond. Ball Charge Distribution 1961 Ball Charge Distribution 1999 Ball Size Balls Ball Size Balls inch cm Number Weight (g) inch cm Number Weight (g) 43 8803 25 5690 67 7206 39 5137 10 672 60 4046
WhatsApp: +86 18838072829
Since there are not that many small SAG mill operations of under 2000 TPD, and most sub2000 TPD mills are built with rod mills and/or ball mills only; the upstream crusher plant needs to have sufficient crushing power to provide a P80 to grinding of typically <″ (40 mm) and often as finely crushed as <3/8″ (9 mm).
WhatsApp: +86 18838072829
How to use this calculator: Choose a type of operation (drilling, reaming, boring, counterboring, face milling, slab milling/side milling, end milling, or turning), select your stock material, choose a material for the tool (highspeed steel or carbide), input the quantity of teeth for the tool and the diameter of the workpiece/cutter. Hit the ...
WhatsApp: +86 18838072829
Typically R = 8. Rod Mill Charge: Typically 45% of internal volume; 35% 65% range. Bed porosity typically 40%. Height of bed measured in the same way as ball mills. Bulk density of rods = tons/m3. In wet grinding, the solids concentration 1s typically 60% 75% by mass. A rod in situ and a cutaway of a rod mill interior.
WhatsApp: +86 18838072829
P80 Product Size 70% minus 200 mesh (75 microns) Ore's Bond Work Index Circulating Load 400% Ball Mill Power 800 HP. ... The solids content of the ball mill discharge is controlled by a ratio control loop, whereby barren solution addition is proportional to the ball mill feed. The set point of the controller is the percent solids desired ...
WhatsApp: +86 18838072829
A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
Copyright © 2023 GMC Co., Ltd. SiteMap
