Grinding & Classification Circuits

Grinding & Classification Circuits2018-06-17T09:51:34-04:00
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Started by Babacata
Could someone please provide me a link or probably send a copy of Moly-Cop Tools 3.0 software? It's not listed on their site anymore. Thanks.
Last commented on by banyechan
Hi,can you send me Moly-cop tools 3.3 for a share? Thanks a lot
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Started by John Leumas
I am looking for information on methods to weigh or count grinding balls being added to a large SAG mill. We have rotary feeders and launders that allow balls to roll by gravity from the launder to the SAG mill belt conveyor about 50 ft upstream of t...
Last replied to by Todd H
I would calibrate the bin level and install an ultrasonic sensor in it.  Alternatively, you could install a metal detector and use the output to count balls going into the mill. https://buntingmagne...
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Started by adbcbd
Hello,  I have around 10 Kgs in total of different stone ores like sulfur and quartz and stibnite that I need to grind to 1.5mm.  However, I don't want to pay much and don't have so much free time to spend grinding. I tried to search for solution...
Last commented on by SmartDog
Time vs money
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610
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Started by Partha@Mech
E= 10 Wi (1/√P80- 1/√F80) E= Specific Energy, Wi= Work Index,P80= Output,F80= Feed After this we need to multiply certain factors such wet/dry Factor, Separation Factor, Dia. factor,  Open/Closed Circuit Factor etc.. E= 10 Wi (1/√P80- 1/√...
Last replied to by David
"Awaiting for real answers based on research" Really? And you want this.... for free? You should contact info@bhagawati.com They are expert at this and certainly should be able to answer this very...
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435
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Started by psvssharsha
How to control Ball mill grinding & classification circuit without DCS system for effective control on continuous operation
Last replied to by David
Hello C yes, Saeed is correct. Power-draw is your main driving factor. % Solids out of the mill is next. You will play around and identify what the optimum % Solids is for your situation. Personally,...
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Started by Ilkaar
Dear all,  What can be the causes of coarse balls ejection from a ball mill? this happened after liners replacement.  
Last replied to by htnenado
Any increases to density within the mill when the ball loading is high can cause the balls to discharge. Keeping the BM % solids low will allow you to operate with higher loading but the mill becomes ...
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Started by Millza79
For an existing concentrator (with existing installed crushers and mills) where a new deposit is being locked at. What comminution tests should you do? I would have thought SMC and BBMWI are a must, with maybe UCS and crushing impact tests also impo...
Last commented on by Alex Doll
hmm, the parser screwed up the maths. It was supposed to say "current ore RWi much less than BWi, but new ore RWi much greater than BWi", then...
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Started by weethengtan
Hi, there. Currently our open-circuit, wet overflow rod mill 6ft x 12ft, feed size
Last replied to by weethengtan
Hi Alex, Thank you for your guidance. I came across a relationship in an article stating Q = k*L*D^2.5 where Q is capacity and k is a constant. It's great to find similarity with your relationship in ...
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Started by banyechan
Our customers in CaCo3 grinding fileds,just sent us operating conditions in grinding.What types of balls are better for drying grinding?  
Last replied to by weiliu2002
Cast balls are better for drying grinding and forged balls are not. In a drying grinding circumstance, working temperature of balls can reach to 300 above which will temp the forged balls and therefor...
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Started by Brendan158
Hello Mets, I'm looking for information around rod mill media size selection to prevent rod tangling. There is the rule that the length of the mill/rod should be 1.4 to 1.6 times the diameter but there is very little information on if there is a min...
Last replied to by Brendan158
How does make-up rod diameter affect the risk of tangling?
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Started by akfury
Running flat gold & Garnet through impact mill / grinder. Will the gold roll up into a ball somewhat? I'm talking 20- concentrates.
Last commented on by SmartDog
Other than by hand, no
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335
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Started by Jorge Quintanilla
Tin Ore Classification  One of the most recent tin projects in Bolivia involves the classification into four ranges:1. -1,800 micron +850 micron2. - 850 micron +212 micron3. -212 micron +45 micron4. -45 micron +30 micronTo obtain this classificatio...
Last commented on by Jorge Quintanilla
Excellent observation. I appreciate the comment that helps us in making decisions
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264
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Started by akfury
Running this dirt in any gravity separation I've tried induces packing/plugging and gold loss. All kinds of sluice setups & centrifuge. Centrifuge struggles and is too little production. Looking at Hydrocyclone for results? Problem areas are mainly 3...
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Started by Namo2014
I need help on calculating (formula) SAG Mill volume solids and what a power load curve means? I have attached a sample of bearing press vs power draw for one of our SAG mills. Could someone help me with what my load curve means?  
Last replied to by Jorge
Follow the link below, https://www.911metallurgist.com/ag-sag-grinding-circuit-automatic-control/
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777
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Started by m_aazami
Hello Everybody my question is: in whole the document about technical specification of ball charge media of ball mill, it is stated that the hardness of ball media in startup of the plant should be a little lower than ball media in continuous opera...
Last replied to by SmartDog
The slightly lower hardness is to allow the media to establish a natural size distribution faster.  When the mill is first stated a guess is made is to a media distribution and then it is operated to...
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Started by Saghar
Hello, I am working on air classification operations in a cement plant. The final air classifiers (High efficiency type, manufactured by polysius) have high values of bypass, let's say around 40%. I wanted to know what are common practices to reduce ...
Last commented on by Saghar
That was very useful. Thanks I will declare the results if I can change the feed rate of the classifier
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Started by Saghar
Can anyone kindly help me determine selection function and breakage function in a laboratory rod mill? I need a reference that completely describes the process of determining grinding kinetics in rod mills
Last replied to by Saghar
Thanks for answering. I have determined the selection and breakage function in case of ball mills previously, using modified H&F method. Now I need to know that how different is the procedure for a r...
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608
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Started by Dachmann
Hello, I was told in this forum that economic efficiency is one of the major reasons for the ongoing popularity of Tumbling Mills in mineral processing. Concerning my questions I need some insight of experts with practical experience. Looking at SA...
Last replied to by David
A case by case trade off is to be done. Farnell Thomson Montreal based could do this. Here is a paper you will find useful.
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763
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Started by MSKabir
During rotation of a SAG mill, the three prominent zones are the grinding zone, tumbling or cascading zone and the cataracting zone (crushing zone). Are there any studies about the percentage of wear in the areas mentioned and what type of wear domin...
Last commented on by MSKabir
Thank you so much for the valuable feedback.
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691
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Started by MSKabir
After perusing through research articles I found out that the two most commonly used mill liners are pearlitic steel and white cast irons. However, I was wondering, what situations would involve using pearlitic steel as liner material or vice versa d...
Last commented on by MSKabir
Thank you so much for the feedback
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Started by JuniorMet
How do you determine the charge level in a SAG mill and/or a ball mill (balls+pulp+rocks) and the interstitial space?
Last replied to by David
https://www.sagmilling.com/tools_millfilling
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Started by JuniorMet
Hi colleagues. I want to know what is the percent solids we are working at, inside the sag mill. Should I sample the pulp discharged to the sump and measure % solids there? How can I calculate the solids percent using the circulating load or the over...
Last replied to by Todd H
It is always best if you can measure the solids directly but it is not always possible plus on a SAG there is often a trommel and a screen in the way.  You need to measure all the flows and the sump ...
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Started by Sarah
Hello everyone,   I would like to know which one is efficient in iron ore crushing and grinding circuit: Jaw crusher+SAG mill+ ball mill 3 stage crushing + 2 stage grinding (ball mill)   Regards, Suvd
Last replied to by SmartDog
Without looking at the tonnages involved and the ore characteristics it cannot be determined. Both are efficient depending on your ore.  The actual efficiency of one over the other is dependent on th...
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Started by Chisomi
what is dry classification
Last replied to by SmartDog
The following is a very simplified look at the topic. Mechanical classification is primarily done using vibrating screens or profile wire/sieve bends screens.  Centrifugal classification primarily d...
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Started by Millza79
For a SAG Mill or ball mill; what is the difference between a installed motor power and Mill Motor Size at Pinion?   And why do SAG mills have a different Mill Motor Sizes at Pinion than ball mills (when they both have constant installed motor pow...
Last replied to by SmartDog
In addition to Alex's comments, there are additional "losses" in the mechanical side.  The input to the gears  and the output from the pinion to the shell are always different, with mechanical losse...
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Started by richardh
Hi What is the optimum method of controlling a cluster of hydrocyclones used in a closed mill circuit so as to obtain the best performance?    Is simple sump level control sufficient?
Last replied to by Alex Doll
Ideal hydrocyclone control is constant pressure, feed density, and flow rate. These three things are difficult to control in the real world which is why people settle for poor hydrocyclone performance...
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Started by Eder Figueiredo
Hi everybody, During performing some Ultrasonic Testing (UT) to measure the thickness of the mill discharge trunnion I found excessive wear. I can say it is in a critical state. Everything indicates that slurry seeped underneath trunnion or shell ...
Last commented on by Eder Figueiredo
Thanks, David. I will look for a Devcon representative in Brazil and also consider Hoffman engineering as a second option. For temporary repair with reinforced urethane filler. Does the structural ...
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803
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Started by Babacata
Dear All, I would appreciate your opinion, if you could give me some indication on our ball consumption at our factory, do you think that there is a room for significant improvement?   I am attaching the basic data sheet of our zinc-lead mine/fac...
Last replied to by David
if you want to reduce ball consumption, reduce your ore feed size. 35 mm is large https://www.911metallurgist.com/typical-average-grinding-ball-consumption/
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Started by Tristopher1234
Our 12,500,lb cap. Ball mill is not level. This causes the charge to be 65% or so on one end and the other level is way below the balls on the other end.  I would think that this would not allow the material to grind properly on either end. The mil...
Last replied to by Alex Doll
What happens when you increase the water addition?  A higher pulp density might help to level out the charge. Is the mill actually level, or is it tipped towards one side? Are the lifters the same ...
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Started by Rahul bhoraniya
hello everyone  please tell me how to measure capacity of batch type ball mill used in Ceramic body or Sanitaryware body? How to calculate guide me
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Started by hojjat78
can we use polyurethane liners for ball mills? compared to rubber based liners, what are the advantages and disadvantages of polyurethane liners  
Last replied to by hojjat78
thanks
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777
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Started by Sandyhose
Hi There, We have a wet overflow rod mill which is being used to grind Malachite. We want to convert it into ball mill to get the finer product 80% passing 70 micron. Can we do the same? simply, can we convert rod mill to ball mill? if yes then wha...
Last replied to by SmartDog
Balls are usually added to the mill with the ore feed (after the initial charge).  This requires a bin over the feed belt and feeder to add the balls at the desired rate.  These are usually of the t...
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Started by Hamid72
Hello everybody We have a ball mill in our plant with 2m diameter and 7 m length. I think that It is not a standard ball mill. Now I want to calculate the power draw of this ball mill and know how much must be the loaded ball in this ball mill. Can ...
Last commented on by mashudu
very helpful. thanks
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798
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Started by Hamid72
We are adding a new line of Iron concentration in our plant. And now I want to sizing a hydrocyclone so I need to know circulating load. How can I calculate the best circulating load for this circuit? Thank you for your help
Last commented on by Hamid72
Thankyou so much
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1129
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Started by amit_antu412
How can i control mill load with Trunnion bearing pressure ? We have faulty load cell in our SAG mill. We have previous relation trends when load cell was working fine. We need to develop relationship formula . Please assist me.
Last replied to by Jorge
Follow the link, https://www.911metallurgist.com/grinding/bearing-pressure-to-mill-load-control/ https://www.911metallurgist.com/ag-sag-grinding-circuit-automatic-control/  

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