Sponge iron briquettes are actually called compact blocks of sponge iron. Briquetting dates back to the last two hundred years, but its use has become more widespread in recent decades. Briquetting is done in order to make optimal use of low-efficiency materials. Briquette is a product obtained by direct regeneration of pellets. To get acquainted with the pelletizing process, you can read the article Pelletizing and iron concentrate.pay attention to this issue.