Regarding Si Mn Alloys

Sure, if it gets hot enough.

Do you know the melting temperatures of the two metals?

Do you know how hot the furnace gets?

Did you think about this before asking the question?

Melting point of pure Si (2,570° F) and Mn (2,275° F)...its possible if your induction furnace can achieve these temps.

A simplistic answer to a simplistic question

More info required.

There are induction furnaces capable of melting Si Mn ferro alloys. I have no idea if your furnace is capable of exceeding the critical temperature. I also have no idea if you are capable of operating your furnace at the necessary temperature to safely melt this alloy.

In induction furnaces the material has to be magnetic and higher the magnetic losses - easier it is to melt. Further if the material loaded is say for example bigger lumps- magnetic coupling is on the surface -closer to coil. If the material is in smaller pieces or near powder form - it couples better and is easier / faster to melt. These are simple thumb rules with induction melting.

'...In induction furnaces the material has to be magnetic...'

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That statement is a bit odd.

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Let's begin with the problem of specifying a material must be simply 'magnetic'. Ferromagnetic? Antiferromagnetic? Ferrimagnetic? Diamagnetic? Paramagnetic?

All materials are affected to some degree by magnetic fields. Requiring that a material simply be 'magnetic', is as superfluous as requiring that it be of a nonzero positive mass, or that is take up some space.

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It might be argued that you were using 'magnetic' as it is commonly used in non-technical language as an equivalent to 'ferromagnetic'.

But, since ferromagnetic materials generally have curie points that are below their melting temperature, ferromagnetism cannot be a necessary quality of material to be melted in an induction furnace.....

....if it were the case, the material would heat only to the curie point and no further, i.e. remain solid.

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It will help if you consider that an induction furnace works in a process similar to that employed in induction cooking stove tops...and note that the cookware specified is typically aluminum or copper (I think iron is eschewed for some reason).

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The point here is that an induction furnace works predominantly by electromagnetic induction of currents within the substance to be melted. Heat from resistive losses from the induced currents is the causes the temperature increase common to any material melted in an induction furnace.

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In ferromagnetic materials additional heat from magnetic hysteresis will contribute to the increase in temperature, but it is not alone in its contribution nor is it necessary for induction heating.

"It will help if you consider that an induction furnace works in a process similar to that employed in induction cooking stove tops...and note that the cookware specified is typically aluminum or copper (I think iron is eschewed for some reason)."

You've got that REVERSED!

I don't know what kind of induction cooking stove tops you are referring to. Both of mine (and all others that I've heard of) require ferromagnetic material in the cooking utensils. Cast iron works fine, as do many stainless steels; aluminum, copper, and non-magnetic stainless steels do NOT! Clearly these units use some other property than eddy currents to heat the utensils. I wish I knew exactly what property(ies) they do use...

As to induction stove tops, I stand corrected. Thank you for making me aware of my misconceptions.

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It appears only recent higher frequency induction stove tops are capable of cooking with aluminum, copper and non ferromagnetic stainless. The general case is indeed that ferromagnetic cookware is required.

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On the subject of using induction to melt metal I still maintain that being ferromagnetic cannot be a necessary property since that property is lost prior to reaching the melting point.

I had designed a induction cook top myself. When aluminum or copper vessels were placed - the induction coil currents were extremely high- as compared to a case when magnetic material is placed. So it is not true that aluminum or copper can be used- I have seen waveforms and difficulties arising from it. I did visit local market to look for aluminum pressure cooker which is said to be compatible with induction cook top- they are slightly more expensive than normal cooker meant for gas stove. When I saw - beneath an iron plate had been press fitted (may be cold welding) below the aluminum bottom.

I'm not sure about the other competition, but at least one manufacturer, Panasonic, has been selling induction cook tops that work with copper, aluminum, and other nonferromagnetic materials since at least 2004.

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I realize that this is a relatively recent development, and as I previously noted, my original comparison of induction cooking to an induction furnace was a poor one.

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All that being said, writing , 'it is not true that aluminum or copper can be used', is simply not true. In fact they can. Not on every stove top, but never the less, on some.

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Beyond that, back to motivation for my comment, ferromagnetism (if that is what you meant by 'magnetic') is not a necessary property of material to be melted in an induction furnace.

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Can we agree on that? ...or are you saying pure silicon is ferromagnetic?

I've been aware that someone was working on an induction cooktop that would work with non-magnetic metals, but I haven't seen one yet. Such a device would have to somehow sense the electrical and magnetic properties of the vessel being used, and adjust at least the frequency accordingly. Our existing devices do sense the presence of appropriate material, I presume by detecting the reflected current in its coils, and turn off in the absence of energy absorption.

Unfortunately, the text of your Panasonic link makes no mention of induction at all!

If you find a link to such a device, I'd be interested in seeing it.

You are obviously correct that induction melting can not depend exclusively on ferromagnetic properties, as the heating would cease as soon as the material reached its Curie temperature.

Unfortunately, the text of your Panasonic link makes no mention of induction at all!....

If you look under the energy saving devices section, it is listed a IH cooktop... presumably for Induction Heating.

It appears that the units have been sold for a while but only in Japan. If you Google 'all metals Induction cooking' you will find some ads and some tech manuals... all rough translations from Japanese as far as I can tell....

I would not presume IH is an abreviation for Inductive Heating because it could just as easily be an abreviation for Infrared Heating.

That wasn't my starting point, and not a presumption.

Here is another discussion in Chowhound? I think there is a lack of english info because it is sold only in Japan, for what reason I do not know...

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Here is a more technical article about the IH technology.

Thanks - I missed that. I did a search for 'induc' and got one instance of 'induced', but when I added the 't' (induct), it said 'none found'

I don't understand why induction cooking is so expensive here in the US. It is much cheaper (and therefore much more common) in Europe, and apparently in Japan as well.

We have a cooktop with two radiant elements and two induction elements. The only time the radiant elements get used is when we need more than two pots at the same time.

My Presto C601A 6qt stainless steel pressure cooker, purchased approximately 40 years ago, works fine on either our induction cooktop or our portable induction cooker. In fact, we use it about twice a week to cook artichokes; with about a half inch of water, the water is boiling in one minute, and the 'top hat' is bobbing nicely in two minutes. The 'chokes are done in 15-17 minutes, depending on size.

Even if aluminum did work, I'd still avoid it! Look at any well-used aluminum pot, and it will be significantly pitted. Those pits were caused by aluminum being dissolved into the food...

As weak as the question is, you have overlooked that he/she mentioned "Sn Mn ferro alloys."

This implies some magnetic reactivity.

Also, your input on the relation of surface area to melt effectiveness/efficiency is a pursuit of a tangent to a circle that is still just an arc.

More info required.

What is the purpose of melting Si Mn fines in induction furnace?

Is it to add Si and Mn in an iron or steel melt? If yes melting fines will be ok.Ususal addition method will give you right additions.

I forgot to mention my own experience in melting silicon using induction heating. Silicon is molten and recrystallised into mono crystalline silicon regularly in semiconductor industry - Wacker Chemi is a well known company in this field. I installed a machine myself supplied by Siemens decades ago.

Here a water cooled single turn copper coil was excited with - I think at 2 to 3 MHz, 20 KW power was pumped in- initially to heat graphite ring around a silicon rod.. The graphite ring would get hot and go to White heat. The radiation from graphite was melting silicon rod. The graphite ring was removed and silicon would melt on its own- as its resistivity falls and is able to carry on melting and solidifying. This s called floatzone crystal pulling - where molten silicon is held between two silicon rods- without any container ( as any container may add contaminants).

This sentence found in another comment of yours just a couple spaces up....

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'...In induction furnaces the material has to be magnetic ....'

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doesn't appear congruent with the sentence found in the comment you just made...

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'...I forgot to mention my own experience in melting silicon using induction...'

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It's probably that I'm not that quick on the uptake....care to alleviate my confusion?