Sinter plant

From Global Energy Monitor
This article is part of the
Global Steel Plant Tracker, a project of Global Energy Monitor.
Download full dataset
Report an error

A sinter plant is used to agglomerate iron ore to produce sinter, a product that can be used in a blast furnace.[1] According to the U.S. Environmental Protection Agency, the sintering process converts fine-sized raw materials, including iron ore, coke breeze, limestone, mill scale, and flue dust, into an agglomerated product, sinter, of suitable size for charging into the blast furnace.[2]

Iron ore cannot be used directly for production of iron. Sintering is a pre-treatment process in iron production for preparing the charge material called Sinter.[3] A mixture of iron ore powder, fluxes and recycled substances from the steel plant are mixed together and burned in a sinter plant to an open-grained, consistent substance. The sinter is then crushed, cooled and screened for dust.[4]

Sintering stands out as the most economic and widely used agglomeration technique for preparing iron ore fines for use in the blast furnace. In comparison to pellets, sinter production is cheaper, and compared with lump ore, fluxed sinter is often more reducible with better softening characteristics. In modern blast furnaces across East Asia, iron ore sinter typically constitutes more than 60% of the blast furnace ferrous burden.[5]

The Method

Before sintering the iron ore lumps undergo granulation process, which is the homogenization of the iron ore mixture in a rotating drum with 7-8 % of water for obtaining of a pre-agglomerated product, which is then delivered as a layer over a continuously moving grate or strand for getting the sintered product. This process ensures an adequate sinter bed permeability and hence good productivity of the sintering machine.[3]

Sintering is a thermal process which involves heating the pre-agglomerated product (a mixture of iron ore, return fines, recycled products of the steel plant industry (such as mill scale, blast furnace dusts, etc.), slag forming elements, fluxes and coke fines) at 1300-1400 °C to produce a semi-molten mass that solidifies into porous pieces of sinter. The resulting sinter has the size and strength characteristics necessary for feeding into the blast furnace.[3][6]

Flowsheet of a Sinter Plant (Source: Ispat Guru)

Types of Sinter

Sinters are classified into three types, namely: non-fluxed or acid sinter, self-fluxing or basic sinter, and super-fluxed or super basic sinter. There are basically no flux present or added in the ore in case of Acid sinters. Self-fluxing sinter has sufficient content of CaO (lime) in it which is required to flux its acid components (SiO2, and Al2O3). Super-fluxed sinter has additional content of CaO for fluxing of the acid components introduced in the blast furnace through other burden materials.[7][3] In case of self-fluxing and super-fluxed sinter, the lime reduces the melting temperature of the sinter mix and at relatively low temperatures (1100 deg C to 1300 deg C) strong bonds are formed in the presence of FeO. Adding flux to the sinter has multiple advantes including generation of slag with the impurities in iron ores and solid fuels, improving the physical and metallurgical properties of the sinter, reducing the melting temperature of the sinter mix, and reducing or eliminating the addition of limestone in blast furnace saving fuel needed for calcination of limestone.[3]

Decarbonisation strategies

Substituting coal and other fuels in the sintering process by biomass as a source of fuel or reductant is an important decarbonisation strategy that can be adopted in Sinter plants.[8]


  1. Sinter Plant, ScienceDirect, Retrieved on: Sep. 21, 2020
  2. Cestari, Alison (2019-06-11). "Sintering: A Step Between Mining Iron Ore and Steelmaking". Advancing Mining. Retrieved 2024-03-20.
  3. 3.0 3.1 3.2 3.3 3.4 "The Sintering Process of Iron Ore Fines – IspatGuru". Retrieved 2024-03-20.
  4. "Raw materials - Sinter plant | ArcelorMittal". Retrieved 2024-03-20.
  5. Lu, L; Ishiyama, O (July 2015). "Iron ore sintering". Mineralogy, Processing and Environmental Sustainability: 395–433 – via Elsevier Science Direct.
  6. "Sinter Plant" (PDF). Ministry of Steel, Government of India. Retrieved 20 March 2024.{{cite web}}: CS1 maint: url-status (link)
  7. "Sintering plant at a glance". SlideShare. 2014-10-27. Retrieved 2024-03-20.
  8. "Pathways to decarbonisation episode two: steelmaking technology | BHP". Retrieved 2024-03-20.

This page uses material from the Wikipedia page Sinter plant under the provisions of the Creative Commons Attribution-ShareAlike 3.0 Unported License.