Is it possible to use this to smelt iron instead of steel? 

I do have a qualm with your idea of when VS timeline depicts. The devs want to implement steam energy at some point... The steam age lasted from 1770 to ~1915. I love your implementation and you made your mod feel so vanilla+ that I feel you need to give yourself significantly more credit.

Hi,

Can you make a fork that adds requirement for steel door instead of iron ones and refractory bricks, so that there was requirement to have at least once fired the cementation furnace?

Jariman I updated the moddb page to match the mod guide in-game. You'll need to first place a fireclay crucible on the ground, then right click it with steel/blistersteel bits(+flux), then seal it by right clicking the crucible with a fired crucible lid.

can any one create youtube guide for this mode

try do 

Only a fireclay crucible can withstand the high temperatures necessary to smelt steel.
The crucible needs to be buried in coke, so it must be sealed with a lid.
To create a sealed crucible, combine a fireclay crucible, 120 steel bits, and a crucible lid.

If using blister steel, a flux will need to be added.
Combine a fireclay crucible with 120 blister steel bits, a crucible lid, and one of the follow flux materials:
1x Powdered Borax
3x Crushed Quartz
6x Lime

but nothing :(

This is an excellent mod. I always end up with leftover scraps after processing steel, and this mod puts an end to my frustration—that feeling of having the resource right there but being unable to actually use it. I would be incredibly grateful if you could also add this functionality for meteorite steel and iron scraps. After all, these two metals are similarly impossible to revert to a usable state, yet a massive amount of material is left over after crafting armor or sheets of steel and iron. Thank you so much for creating this mod!

Yukari_75 This is true, I actually learned about wootz steel (I had only known it as Damascus) while working on this mod but decided to focus on the more modern crucible process due to its relative simplicity (heat unrefined blister steel + flux -> cast refined steel). While wootz steel is a crucible steel, it isn't actually poured cast steel, instead left in the crucible to cool and harden, the crucible broken to obtain the steel, then forged into ingots/tools. Benjamin's process exclusively used blister steel and combined it with flux materials to refine it into a homogenous high quality steel. Though the process did eventually change to include the use of wrought iron, this ability to pour cast steel directly from iron+carbon wasn't developed until the mid 1800s, once people understood the chemistry behind steel along with a number of other advances in material science. For this reason, I don't think I'll add the ability to pour cast steel directly from iron+carbon in this mod.

This page is a great read on the history of crucible steel: https://smallworkshop.co.uk/2017/12/04/crucible-steel/

That said, I think the ancient process (specifically Wootz steel made from iron/magnetite bits) would be a great feature, requiring a longer cooling process that occurs within the crucible, requires breaking the crucible to extract the cooled ingot(s), tempering of the resultant steel, then forging into desired tools. To balance this earlier steel, that process would indeed be extensive but the resulting steel could also be of a slightly higher quality (producing true Damascus/wootz steel). I haven't thought that process through exactly, but may make for the next major update or a separate release :)

I agree with Yukari_75 said method from Benjamin was used to make steel from Wrought Iron (The iron version we make in the game), it should have about 1-2% Coke/Charcoal to 98-99% Iron (the pure iron after being processed in the crucibles) ratio for the steel to be made. I would honestly suggest the clay crucible to be disposable too, like have a chance to be broken each time its used, and a recipe to use tier 1-3 fireclay to make more durable crucibles for this process.

Aye would also love the ability to create steel with this as well.

Could you add an iron crucible, where its filled with hematite/whatever iron ores?

While the crucible steel you used as a reference is beyond the time period used as a reference for much of VS, crucible steel in general is much older, dating back to the 1st millenium BCE
Addition: I think people should have the option of using iron bits(not ore nuggets, pure iron bits) instead of steel bits, but need to add charcoal or coke with the iron bits

This looks awesome, however considering the requirement to seal the crucible, I'm wondering if this could work to make the steel alloys from some mods like CAN Metals or if it would work for other metals, like iron or cupronickel

This mod is a great addition and works really well, thanks!