Aglomerasi Bijih Besi [PDF]

Citation preview

Universitas Sultan Ageng Tirtayasa Fakultas Teknik Teknik Metalurgi



Reduksi Bijih Besi TMT 614306



Aglomerasi dan Karakter Feed/Umpan



G ANJIL 2 0 18/2019



Outline Aglomerasi



Karakter Umpan



Pelet Sinter



Definisi Pembuatan



Direct Reduction Indirect Reduction



Agglomeration The primary purpose of agglomeration is to improve permeability and gas solid contact. A good agglomerate : 1. Should contain 60% or more iron, a minimum of undesireable constituents, a minimum of material less than 6 mm and a minimum of material larger than 25 mm 2. Should be strong enough to withstand degradation during stockpillling handling and transportation. 3. Must be able to whithstand the high temperatur 4. Should be reasonably reducible



Agglomeration Sinter Untuk Blast Furnace



Pellet untuk Blast Furnace dan DR



Definition Sintering and pelletizing are processes by which iron ore fines are agglomerated into larger places with or whitout incorporation of lime and magnesia as fluxes



Outline Aglomerasi



Karakter Umpan



Pelet Sinter



Definisi Pembuatan



Direct Reduction Indirect Reduction



Pellet Pelletisation is a process af aglomeration of iron ore. Particle smaller than 0.2 mm are converted into 12 – 15 mm green pellet. On drying and firring, green pellet become hard and strong to be used as feed for BF and DRI units. Addition For pelletizing : Binder : Bentonite (Al2O3.4 SiO2.H2O), clay or hydrated lime Consumption : 6.3 – 10 Kg/ton feed Water : Optimum moisture content is 9 – 12 % 1st patent of pelletizing in rotating drum ❑ Anderson, Sweden, 1912 ❑ Brakelsberg, Germany 1913



Properties of Bentonite



Typical chemical composition of magnetite/hematit pellet feed % Fe



65.5



SiO2



7.8



Al2O3



0.5



CaO



0.5



MgO



0.6



Mn



0.25



P



0.032



S



0.003



TiO2



0.1



Moisture



10



Grain Size : < 0.2 70 – 80 % < 40 micron



Green Ball Formation When two ore particles which are coated with binder slurry come in contact with each other during to motion on pelletizing machines, they collide with another particle to form liquid bridge acting as capillary. Surface tension of the fluid capillary keep the particle together



Methods to produce green pellet



Rotating Spiral Scraper



Variable Speed 8 – 14 rpm



Angle Variable = 6 – 10 °



Dimension of Rotating drums for green pellet production with capacity 130 ton/h ROTATING DRUM PELLET



Rotating Disk to produce green pellet Dimension of Rotary disk for green pellet production with capacity of 90 – 140 t/h



Rotating Disk To produce green pellet



Rotating Disk To produce green pellet



Mixture ready for green ball



green ball



Pellet Hardening Green pellet is hardened by heating (firring at sufficiently high temperature ± 1200 C)



Strong bonding of pellets is belived to be due to grain growth from oxidation magnetite to hematite Methods of pellet hardening ◦ Traveling gate ◦ Greate kiln ◦ Shaft futrnace



Typical Pelletizing plant



Zone of the indurating Zone



Sintering



Definition : Burning of fuel ( coke breeze, anthracite) mix with iron bearing material, e.g fine iron ore, concentrate, steel shop waste under control conditions



Sintering mix composition Definition : Burning of fuel ( coke breeze, anthracite) mix with iron bearing material, e.g fine iron ore, concentrate, steel shop waste under control conditions



Iron Ore : 55.5 % Circulation component Fluxes Return Material Raw mix



: 4.8 % : 12.7 % : 27 % : 100 %



Raw Mix Coke Breeze Moisture



Sinter mix



: 92.1 % : 5.6 %



: 2.3 %



: 100 %



Sinter Feed Constituents



Iron



Iron content is to be as high as possible > 60 % is preferable, 50 – 60 % is adequate, 5.5 % is considered high,