Iron dust is an item from the Industrial Craft 2 mod that can be used to create iron ingots. It can be created by putting iron ore into a macerator. Each ore will grind down to two iron dust, effectively doubling the product. An alternative method is to craft it using tin and copper dust.
This can be very useful since Iron is one of the most commonly used materials in Industrial Craft 2 and far less common than tin and copper. Although it costs quite a bit of resources to craft, it may be useful when you're short on your iron supply.
The following method will create a 'Small pile of Iron Dust'. Combine two of these piles to create a normal one.