Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Mill Scale Uses and Applications
Q. Is mill scale used as a black oxide for production of thermit portions to welding or the rails?
Mahmood Noori- Tehran -Iran
January 4, 2021
⇩ Related postings, oldest first ⇩
Q. My company uses iron ore (magnetite) in its process. However, a large amount of mill scale has become available and we are looking at it as a substitute or supplement. What is the basic composition of mill scale and the difference between it and magnetite and black iron oxide? Can mill scale be used in place of magnetite or black iron oxide?
Fred S [last name deleted for privacy by Editor]- Charlotte, North Carolina
2002
A. Maybe, Fred. But with no info on what sort of process, there's no way anybody can answer :-)
Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
2002
2002
Tip: Readers often just skip abstract questions;
they want to learn from your actual situation.
Q. Please answer me this question! I need help!
Arash M [last name deleted for privacy by Editor]- Iran
? Hi, cousin Arash. Sorry, but people need to know your intended application to hazard a guess.
Mill scale is the hardened, oxidized, surface that develops on steel as it is hot processed. It contains iron and oxidized iron but probably poorly defined contaminants like oils and carbonates. Putting this stuff into an unknown "process" might work excellently, or poorly, or fail completely -- but powder explosions of all sorts are a commonplace, and the large surface area could cause the reaction to proceed instantaneously and explode and kill people! Please try your best to explain what your intended "process" is. Thanks.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002
A. Our factory mixes a few percent of mill scale into iron ore fines before they are sintered so that we could get a higher grade of Fe content.
Charles Yu- Qingdao, Shandong, China
March 3, 2008
Can Mill Scale replace black iron oxide or magnetite?
2003
Tip: Readers often just skip abstract questions;
they want to learn from your actual situation.
Q. Can anybody tell the difference between Iron Mill Scale, Black Iron Oxide, Magnetite (Iron ore)? If the basic composition is the same, can Mill scale be used in place of Black Iron oxide or Magnetite.
R. Dan- India
A. Well, there have been many attempts to use mill scale but all have failed because of structural faults in mill scale. It cannot be used in most applications but if you tell which application would you like to use it, I think all in the room can guide you better.
Dr Kolbasaki- Russia
2003
A. Mill scale can replace certain percentage of iron ore in steel mill, but usually not exceeding 10%. We are buying mill scale all over the world to supply to steel mills in China.
WQ. Hao- Nanjing, China
April 21, 2011
Q. Would it be possible to use iron mill scale with 98% content of Fe2O3 as raw material for making magnets.
Edward Gantz- Birmingham, England
2004
Q. Can iron mill scale powder be used without purification as black iron oxide for ferrites.
R. Dan [returning]metal , alloys & oxide powders - India
2004
A. Well mill scale needs to be purified as it contains contaminants like sulfur and phos. magnetically it needs to be separated and texture modified by heat treating it to 670 °C. then it can be used as magnetite.
Er manuj kaushesh- Solan (H.P), India
2004
Q. I would like to know more about the uses for mill scale. Also if the product is useful in industry what is the price tag on mill scale?
Chris Scheeperstrader - Richards Bay, South Africa
2006
A. Well I used to use about about 1,000 tons per year. It was used in a ferro-cement mix and poured into a polyethylene shell. These were sold as wheel weights for lawn and garden tractor wheels for extra weight for traction. Weights were 20-75 lbs.
Paul Rybak- Topton, North Carolina
2007
Q. Can Iron mill scale be recycled? if so, by which method since it contains so many substances like Cu, Ni, CaO, SiO, and hydrocarbon.
Terence MbinowohManagement Instructor - Göttingen, Germany
2007
Q. We are exploring the use of mill scale (small percentage) in our Pellet Plant coming up in India. We are beneficiating Iron Ore fines bearing Fe 56% to 300-325 mesh and then using a series of hydro-cyclones to bring the Fe up to 64%. I would like to explore the use of mill scale in crushed form (325 mesh/44 microns) for: 1. upgrading by green ball Fe content & 2. increase the quality of finished pellets in terms of reduction.
Any suggestions / opinions / advice is solicited.
- Kolkata, WB, India
2007
Q. Hi Everybody,
I would like to know what are industries that use iron mill scale as raw materials? What are the industrial uses of Iron Mill Scale? Can any of you help me?
exporter - Coimbatore, India
April 15, 2009
Q. Hi to all of the readers
I just wanted to have a solution about mill scale: how can I remove SiO2 from mill scale.
Thanks
exporter - Karachi,Pakistan
October 16, 2009
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Q. Dear sir Student - Karachi, Pakistan October 21, 2011 |
Q. Dear sir,
Please tell me about iron oxide scale and how to leach it in acidic solution or use it in another application.
My company is a beam and rod rolling mill.
Thanks a lot.
- ahwaz, khuzestan, Iran
November 10, 2009
Q. I have a proposal to compact Mill scale (Fe 60% to 70%) from Steel Mills by briquetting it. The briquettes to be used along with heavy melting scrap in electric arc furnaces. There are briquetting machines available in the world market having a capacity to make 30 to 100 mts per hr of briquettes. The bonding used is Sodium Silicate and hydrated lime. I shall be grateful if you could advise if this method of recycling of Mill scale would be beneficial to steel making in the electric arc furnaces. The costs benefits are considerable given the demand and high prices for heavy melting scrap. Thanks for your time
Regards,
- Mumbai, India
January 9, 2010
Q. Is it possible to use mill scale as the feed in sponge iron production?
Tahsin Rahman- Dhaka, Bangladesh
January 25, 2010
Q. Is the form of iron oxide in mill scale suitable for the adsorbtion of phosphates from water? Does anybody know whether mill scale is ever used in this way?
Jerome Davis- Cape Town, South Africa
September 4, 2010
Q. Dear sir
I'm working in one of the alloy production company, since we started the production of LOW CARBON FERRO CHROME. For this we have taken CHROME ORE, AL POWDER, SODIUM NITRATE & MILL SCALE.
I want to know the main usage of MILL SCALE in this chemical combination, that why we have to use MILL SCALE. Please clear my doubt
employee - Vizag, AP, India
December 31, 2010
March 13, 2011
Tip: Readers often just skip abstract questions;
they want to learn from your actual situation.
Q. Do we rally need magnetite to grind mill scale to 325 mesh?
ASHISH AGARWAL- raipur, India
Q. I own a rolling plant producing structure angles and channels. It generates about 100 tonnes of mill scale per month. Is there some kind of technology that can convert mill scale back to pure Fe which can be melted in blast furnaces to produce ingots and billets. Also, can mill scale be directly melted to produce pure iron. I Would be more than happy to give more information if required.
warm regards,
Abhinav
- Delhi, India
March 28, 2011
Q. Is it possible to produce iron powder from mill scale?
For example, at first we can powder mill scale and then using a gas like CO, reduce the powder to iron powder?
- Ahvaz, Iran
May 19, 2011
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Ed. note-- Gentle Readers: If you know enough about mill scale to be able to pose a question, you may know enough about it to be able to help one of the dozen people waiting in line in front of you. A dozen unanswered questions in a row can be the death of any public forum thread, so there really is no point in making the list of unanswered questions still longer. So we won't waste your time and ours adding additional questions until some answers are posted. Thanks for your understanding, and please try to help!
A. Mill scale is the result of an oxidizing layer of steel products as it is processed in a rolling mill. It is collected with coolant and lubricating oils and normally held in a collection tank/pond. During its mixture with the liquids the steel scale will oxidize further until it reverts to iron oxide (Fe2O3). If the scale is collected and dried right away some will be in the form of Fe, FeO, Fe3O4, Fe2O3 and the total Fe content could be as high as 99% or whatever level the steel products are at the mill. The size of the mill scale will be from dust size in microns up to normally 6 mm, perhaps longer as it is scale it will flake off the steel.
Processes exist to recover and use the mill scale as well as all other iron/Fe bearing materials wastes in steel mills and use it directly in a furnace to make new steel.
- Estacada, Oregon, USA
November 16, 2011
A. Mill scale is oxides of iron and alloying elements present in steel. Obviously, it is a rich source of iron. Most of the steel plants recycle mill scale through sintering or pelletization. However, a value-added utilization of mill scale is in steel making after converting it into briquettes. Briquettes can be tailor made by combining with other Plant wastes, such as coke breeze, lime fines, and iron bearing wastes, to suit a particular utilization. It offers excellent techno-economic benefits.
Yes, mill scale can be converted into pure iron by subjecting it to reduction process. Though it is time consuming, powder iron is manufactured through this route as well.
- Mumbai, Maharashtra, India
May 2, 2012
Q. We are interested in making use of mill scale to recover ferrous by adding the same in induction furnace after making briquets. We need your help in going into the process.
Tipirneni Jeji PrasadEngg Works - Vijayawada, AP, India
May 18, 2012
A. Hi, our parent company in China uses mill scale as a raw material for magnetic material production.
Lei Song- Australia
June 25, 2012
Q. CAN MILL SCALE BE USED AS COMPOSITE MATERIAL?
WHAT WILL THE EFFECT ON ITS PROPERTIES WHEN IT IS CONVERTED TO NANO POWDER?
student - INDIA
January 17, 2013
Q. I have a proposal to compact Mill scale (Fe 60% to 70%) from Steel Mills by briquetting it. The briquettes to be used along with heavy melting scrap in electric arc furnaces. There are briquetting machines available in the world market having a capacity to make 30 to 100 mts per hour of briquettes. The bonding used is Sodium Silicate and hydrated lime. I shall be grateful if you could advise if this method of recycling of Mill scale would be beneficial to steel making in the electric arc furnaces. The costs benefits are considerable given the demand and high prices for heavy melting scrap.Thanks for your time
Regards
Seshadri
- Mumbai, Maharashtra, India
July 16, 2013 2nd Request
Q. I WANT COMPLETE REACTION TO PROCESS MILL SCALE TO BE USED IN REPLACEMENT OF SCRAP IN EAF.
THANKS
STEEL MILL - KARACHI SIDH PAKISTAN
March 22, 2014
A. Mill scale could be pressed by roller type briquette machine. And then it is charged into furnace for recycle. This solution is great for you.
Rexxar Songmachinery - Gongyi, Henan, China
July 13, 2014
Does mill scale have some elemental Fe?
Q. Is there any possibility of mill scale having some Fe in elemental form?
BIVEK KUMARthermite - Kanpur,Uttar Pradesh, India
July 25, 2014
July 2014
Hi cousin Bivek. I don't know the answer to your question, but as the website operator for 20 years I advise that a good and helpful response is more likely if you explain the situation which motivates your question. I'm not here to lecture folks, only to advise what seems to work here. Best of luck, and I encourage someone to prove me wrong by answering anyway :-)
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. We are one of the leading steel plants in our area We are making MS ingots in our induction furnace. Mostly we are using both sponge iron and HMS (heavy melting scrap) as raw materials in our plant.
Now a large quantity of mill scale (Fe 40%-50%) is available in our area. Can we use mill scale as raw material in our induction furnace. If yes, how to use?
- Palakkad, India
July 31, 2014
A. Dear, you can use mill scale while processing of Magnetite in magnetic separator in low intensity after grinding and can be used in pellet making, but it will drop your final Fe in the pellet due to oxidation.
Paras MishraTechnical Control Group : R&D - Ranchi,Jharkhand, India
September 11, 2014
Can't use mill scale in our briquettes -- they lose their resistance
Q. Dear all, in my company we generate 3000 Ton/month of mill scale, 1000 Ton/month of DRI Muds and 3500 Ton/month of Iron Ore fine.
We make briquettes of DRI dust and DRI fines with Sodium Silicate, but can't add the mill scale into the mix due to the briquette loses its resistance.
Have some of you tried to make briquettes with these components? How much pressure is required? I would appreciate if someone can show me what type of machine is used for briquetting.
And anyone know if there are other uses of DRI muds besides the cement industry?
Thanks
- Rosario, Santa Fe, Argentina
October 7, 2014
Q. What standard test method( ASTM, ISO, etc.) is used to analyze "DOUBLE ROASTED MILL SCALE"?
We follow iron ore method:
We analyze Fe, Fe2O3, FeO, S, P. with compatibility.
But problem is that our authority needs a STANDARD TEST METHOD INCLUDING IT'S SPECIFICATION.
Please help me with relevant answer.
- KOLKATA, WESTBENGAL, INDIA
February 1, 2017
A. Sanjay,
Even Google doesn't know what "double roasted" mill scale is. plain old "roasted" mill scale doesn't turn up much either.
What kind of analysis are we talking about here? Thickness? Composition? Perhaps if we better understand what you are looking for, we will be more able to search up an existing standard.
Ray Kremer
Stellar Solutions, Inc.
McHenry, Illinois
February 3, 2017
Q. Good day,
Please advise what is the best way to use Mill Scale in Induction Furnace for steel melting to assist in reduction of carbon content.
If we do use mill scale in induction furnace what lining is recommended? As mill scale oxidizes and erodes silica lining, can neutral lining work?
Steel Melting - Gaborone, Botswana
January 9, 2019
A. Yes... mill scale is being used in induction melting furnaces for carbon reduction using neutral ramming mass as silica ramming mass is unsuitable
Bharat Tank- Chittagong, Bangladesh
February 1, 2019
Q. Is it possible to use a mixture of mill scale, coal (carbon source) and sand(silicon dioxide) for reduction into iron in silica lined induction furnace.
As using directly affects the silica lining adversely so would be it be possible to introduce extra Carbon and silicon dioxide with the mill scale so that the lining is unaffected?
- Chittagong Bangladesh
August 10, 2020
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