Pellet (iron ore)
A pellet is a hard, porous ball, typically 8-18 millimeters in diameter, containing approximately 67-72% Fe and various additives . Pellets are made from iron ore and are used in pig iron production as a starting material for the blast furnace process or direct reduction .
Manufacturing
Sieved and ground iron ore is rolled into green pellets together with water, binding agents and aggregates, which are then hardened in a burning process. Bentonite is usually used as a binding agent; the aggregates are either limestone , dolomite or olivine , depending on the desired chemical properties .
The pellets can be produced on four different types of systems:
- Shaft furnace
- Traveling grate
- Traveling grate / rotary kiln
- Heater
use
Pellets are used in the manufacture of pig iron . They have several advantages over other forms of raw material, such as concentrate or fine iron ore:
- The raw material is easier to transport and store thanks to its uniform shape, because it cannot absorb moisture and remains rollable in silos.
- The composition of the pellets can be easily controlled during production, so that a uniform raw material is created, which makes it easier to control the further processing.
- The porosity of the pellets accelerates the chemical reaction in the furnace, while the mechanical strength is retained even under the thermal load. This prevents the material from caking in the oven and prevents the reducing gases from rising unhindered through the raw material.
literature
- National Steel Pellet Company: Iron Ore Processing for the Blast Furnace
Individual evidence
- ↑ Advanced Explorations Inc .: Iron Ore Products ( Memento of the original from October 31, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English)
- ↑ Outotec: Pelletizing technologies ( Memento of the original from July 31, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (English)
