This mod 2x the resources from the smelters (configurable from 1x to 10x: while in the main menu-> settings-> mod settings). This is not for balance but instead just for a faster game with friends. It greatly reduces the requirement to get more mines and makes a new world much faster to start

To configure the mod: Go to the main menu (no save/world loaded). Then click Settings, then Mod Settings.

For a similar mod for oil processing, try More Resources from Oil Processing