FINMET
A LV IZO B O RLING D EC IN EL LAGA ESTO LA NO
FINMET PROCESS
The Fluidised Iron Ore Reduction(FIOR) process reduces iron ore to metallic iron at high temperature and pressure using reducing gases produced from reforming. improved tly by Fior de Venezuela and Voest Alpine (VAI) of Austria in 1991 culminating in the development of Finmet Process The primary aim is to improve the energy efficiency of FIOR by using top gas for ore heating and by removing CO from reformed gas as well as recycle gas.. The Finmet process is a multiple fluidized bed process which utilizes a H2 rich reducing gas 2 produced by steam reforming.
Iron fines under 12 mm
INPUTS AND OUTPUTS
FINMET PROCESS Hot Briquetted Iron (HBI)
3
HOT BRIQUETTED IRON (HBI) 4
HBI
HBI overcome the problems associated with shipping and handling of DRI
Very much less porous Very much less reactive Does not suffer from the risk of self-heating
5
FURNACES AND EQUIPMENT UTILIZE
FINMET PROCESS FLOWSHEET
double-roll briquetting press
lock-hopper system Reducing Reactors • equipped with internal cyclones
HBI
Recycling Gas Scrubber
Reducing Gas Furnace Air
Natural Gas
Recycle Gas Compressor CO2 removal system
Air Natural Gas
Steam Retonner
FINMET Process 11
12
FINMET Process - concentrate/iron ore fines are fed into an ore drier - the feed is lifted to the top of the FINMET reactor structure and is charged to the reactor train - upper lockhoppers cycle continuously from ambient to reactor pressure - the ore is fed continuously to the reactors out of the lower lockhopper
13
FINMET Process
- uses a train of four fluid bed reactors, with counter-current gas/solids ing down the reactor train
14
feed concentrate enters the topmost reactor ( preheated to 550570C by reducing gas)
15
The beneficiated ore is transferred downward between reactors via standpipes and is progressively reduced, first to FeO, and then finally to metallic Fe.
16
The temperature in the bottom reactor (R1) is in the range of 780800C and final reduction to 93% metallisation is accompanied by carburization of some of the Fe to Fe3C (iron carbide).
17
The hot, fine DRI is then transported by a sealed, pneumatic lift system, or riser, to the briquetter area where it is briquetted at temperatures greater than 650C in double roll briquetting machines to a density of approximately 5 tonne/m3.
18
FINMET Process: Gas Flow
Recycled Top Gas
Fresh Reformer Makeup Gas
REDUCTION
RECYCLED GAS
MAKEUP GAS
Recycled gas
ADVANTAGES AND LIMITATONS
Low production costs with the use of low-cost iron ore fines
ADVANTAGES
Investment and energy consumption comparable with conventional DR processes Superior HBI quality featuring high Fe content and high degree of metallization
ADVANTAGES
Briquettes produced as intact single briquettes without breakage Low abrasion losses during handling and transport due to the highly compact nature of FINMET briquettes Industrially proven
Higher degree of metallization
DISADVANTAGES
This process were difficulties in achieving high degrees of reduction due to temperature control Briquetting of the product