Iron ore fines

FIOR Process. In the FIOR process, shown in Figure 5, sized iron ore fines (0.04—12 mm) are dried in a gas-fired rotary dryer. A skip hoist dehvers the dry fines to lock hoppers for pressurizing. The fines pass through four fluidized-bed reactors in series. Reactor 1 preheats the ore to 760°C in a nonreducing atmosphere. Reactors 2, 3, and 4 reduce the ore at 690—780°C. At higher (ca 810°C) temperatures there is a tendency for the beds to defluidize as a result of sticking or hogging of the reduced material. 

Recycle iron-rich materials such as iron ore fines, pollution control dust, and scale in a sinter plant. 

FASTMET A DR process, using pulverized coal and iron ore fines, heated in a rotary hearth furnace. Under development by Midrex Corporation and Kobe Steel from 1991 apilot plant was operated by Kobe Steel in Japan in 1996. 

ITmk3 [mark 3 indicates that this is a third generation ironmaking process, marks one and two being the blast furnace and direct reduction] A modification of the Fastmet process, for making molten iron. Pelleted iron ore fines are reduced with a solid reductant. The iron in the reduced pellets separates as molten metal, uncontaminated by gangue. Developed in 1996 by Midrex Corporation and Kobe Steel. Commercialization is expected in 2003. 

SPIREX A DR process for making iron powder or hot briquetted iron from iron ore fines. Three stages are used. The first is a circulating fluidized bed preheater whose turbulent conditions reduce the particle size of the ore. The second and third stages achieve the reduction in fluidized beds, fed by reducing gases from a MIDREX reformer. Developed by Midrex Direct Reduction Corporation and Kobe Steel. A demonstration plant was scheduled to be built at the Kobe Steel plant in Venezuela in 1997. 

Waters et al. [5] stated that the presence of iron ore fines in the test sample at levels greater than 10% by mass had a cushioning effect, which reduced lump breakage during drop tests. They also observed that the amount of degradation was not significantly different, when lump iron ore drop on different impact surface. 

FASTMET A DR process, using pulverized coal and iron-ore fines, heated in a rotary hearth furnace. Under development by MIDREX Corporation and Kobe Steel from 1991 a pilot plant was operated by Kobe Steel in Japan in 1996. The first commercial installation was at Kobe Steel s Kakogawa plant in Japan in 2000. Further development of the process took place under the name ITmk3. A variation, known as FASTMELT, conveys the hot iron powder to an adjacent melter. See also MIDREX. 

Sintering machines prepare large nodules (lumps) from beneficiated iron ore fines, and iron oxide containing dusts recycled from particulate emission control equipment. It is estimated that uncontrolled operation would discharge particulate at the rate of about 0.3% of the mass of sinter produced, or about 2,700 kg from a machine producing 900 tonnes of sinter per day. Cyclones can decrease the particulate emission to about one-quarter of these levels. It is also possible to use the sintering machine as a roaster to enable sulfur removal from sulfur-containing iron ores. This produces a more amenable ore, but it also produces sulfur dioxide in the waste gas stream. No emission-rate data for sulfur dioxide in sinter plant exhaust gas is available, since this has not normally been recovered. However, a mathematical model which enables estimation has been described [13]. 

Dewatering and filtration are the most important processes in flotation. It is shown in [161] that the settling rate of iron ore fines can be enhanced 25 to 30-fold at optimum concentrations of... 

An initiative sintering process, named pre-reduction sintering, was developed in Japan to reduce energy consumption and CO2 emissions. This process involved iron ore fines being made into ore blocks as well as direct reduction of the blocks witii a reducing agent on the sintering machine [2]. 

Keywords CFD modef Gaseous leduclion. Iron ore fines Multilayer moving-fluidized bed... 

Iron ore fines flow on the perforated plate with weakly bubbling, so the solid layer formed by the ore fines eould be eonsidered as porous media. Resistance to the gas penetrating the porous media is calculated by means of the Eq.(l). Heat transfer between gas and iron ore fines in zone A is estimated using Eq.(2). 

The solid flow only covers zone D and some mesh elements there are blocked to the solid flow to fit the thickness of iron ore fines layer which are illustrated in Figure 1. Conservation equations of the steady, incompressible solid flow could be defined using the general equation is Eq. (6). In Eq. (6), physical solid velocity is applied. Species of the solid phase include metal iron (Fe), iron oxide (Fc203) and gangue. Terms to represent, T and 5 for the solid flow are listed in Table n. Specific heat capacity, thermal conductivity and viscosity of the solid phase are constant. They are 680 J/(kg K), 0.8 W m/K and 1.0 Pa s respectively. Boundary conditions for solid flow are Sides of the flowing down channels and the perforated plates are considered as non-slip wall conditions for the solid flow and are adiabatic to the solid phase up-surfeces of the solid layers on the perforated plates are considered to be free surfaces at the solid inlet, temperature, volume flow rate and composition of the ore fines are set depending on the simulation case At the solid outlet, a fiilly developed solid flow is assumed. 

Iron ore fines, limestone, dolomite, calcined lime, BF return fines and coke breeze were used and pot grate sintering experiments were carried out. Table I gives the chemical composition of the raw materials in the pot grate sintering test. The size distribution of raw material is shown in Table II. The raw material consists of iron ore fines, limestone, dolomite, calcined lime, BF return fines, coke breeze and sinter return fines. Table III shows the proportion of raw material. 

Material Iron ore fines Limestone Dolomite Calcined lime BF return fines Coke breeze Return fines... 

T. Jiang et al.,"Concept and Research of Composite Agglomeration Process of Iron Ore Fines", (Paper presented at the Proceeding of 2006 National Annual Conference on Technical Exchange of Sintering PeUetizingJfohhot. Jun,2006,) 1-6. (In Chinese)... 

CFD Model Development for Gaseous Reduction of Iron Ore Fines Using... 

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