Metallic iron feed

Test-1, Metallic Iron Feed - Effect of Temperature... 

Direct reduction (DR) is the process of converting iron ore (iron oxide) into metallic iron without melting. The metallic iron product, known as direct reduced iron (DRI), is used as a high quaUty feed material in steelmaking. 

Examples are the heavy metals in feed as vanadium and nickel and other poisons as for instance alkali components, iron and copper. 

Irreversible catalyst poisons (or deposits) can even influence the catalyst during the first passage through the reactor, but are not (easily) removed during the stripping and/or regeneration stages. Examples are the heavy metals in feed as vanadium and nickel and other poisons such as alkali components, iron and copper. 

Feed composition and processing constraints required by direct reduction methods have led to blast furnace reduction of iron ores as the dominant method used to obtain metallic iron. Direct reduction methods remain in favor where there is abundant natural gas but negligible coal reserves, such as in Iran, Qatar, and Venezuela. 

This test was designed to examine the feasibility of sulfur fixation using iron ore instead of metallic iron and to find the equilibrium zinc solubility in Fe-S-O matte. Therefore, this test was carried out under a high gas flow rate and with a low solid material feed rate. Initial matte preparation was done exactly as in the previous test. The molten bath temperature was controlled to around 1350 °C. A solid mixture with 44% zinc concentrate, 48% iron ore and 8% charcoal was injected into the bath at a feed rate of 19.5 g/min with 20 NL/min nitrogen carrier gas to give Pzn = 0.066 atm. 

The experimental program described in this paper confirmed the concept of the process and the thermodynamic analysis. That is, the sulfur in the feed materials can be fixed as a Fe-S-O matte using metallic iron or iron ore while both zinc oxide and sulfide materials can be simultaneously smelted in a single reaction medium. The combustion of carbon with oxygrai inside the matte has been proved to be feasible. 

Besides the metallic iron, a Waelz slag produced from lead residues is advantageous to add into the feed of the Kivcet process. The size of the Waelz slag should be minus 20 mm its moisture content should be no more than 3%. The composition of the mixed feed using Waelz slag is shown in Table I. 

A successful process has been developed by the National Chemical Laboratory using cellulose phosphate as a cation-exchange material for the purification of thorium from rare earth elements. Monazite sand is broken with sulphuric acid and extracted with water to give a solution of thorium and rare earth sulphates and phosphates. This is first treated with metallic iron or aluminium to reduce the ferric iron impurity to the ferrous condition. The solution is then fed through a colunm of cellulose phosphate to absorb the thorium. Some of the thorium is present in solution as a cationic phosphate complex, rather than as simple thorium cations, but both forms are retained by the column to a high degree. Rare earth elements, which predominate in the feed solution, are not appreciably absorbed, and the ratio of thorium to rare earths is increased to about 450. ... 

Poisoning by Metals. The feed to a reformer could contain small amount of metals, such as arsenic, lead, mercury, iron, copper, and so on. These impurities deposit on the catalyst and affect mainly the metallic function and usually in an irreversible manner. Therefore, it is necessary to eliminate quantitatively the metals contaminant from the feed before entering the reforming reactor. The toxicity (number of Pt atoms deactivated by one atom of the poisoning metal) varies from 0.5 to 20 and depends on the metal poison. This toxicity is different for each reforming reaction (136). 

Other common transition metal corrosion products typically monitored at various sites within the plant include iron, copper, nickel, zinc, and chromium. More than 80% of BWR plants analyze for iron, nickel, copper, and zinc in reactor water, and nearly all of the BWR plants determine these metals in feed water. In addition, zinc is also an additive used in many plants to control the shutdown radiation dose rate. Nickel and chromium are corrosion products in BWR plants fi-om stainless-steel piping. The best selectivity and sensitivity for achieving low to submicrogram/Liter detection limits for transition metals can be obtained by separating transition metal complexes using pyridine-2, 6-dicarboxylic acid (PDCA) or oxalic acid as chelators in the eluent, followed by postcolumn derivatization with 4-(2-pyridylazo)resorcinol (PAR) and absorbance detection at 520 nm (see Section 8.2.1.2). This approach was successfully used to determine trace concentrations of iron, copper, nickel, and zinc in BWR and PWR matrices [197]. Figure 10.113 compares the chromatograms from the... 

Water is evaporated in the upper part of the shaft, followed by decomposition of the plastic components as the temperature rises to 500°C. Lead also melts and reacts with Pb02 to form PbO. This is reduced by CO to lead further down the shaft, and sulfates are reduced to PbS. A feature of the Varta process is the use of metallic iron to react with PbS and form lead and FeS as a matte, thus capturing the majority of the sulfur in feed. 

Other compounds which may be found in crude oil are metals such as vanadium, nickel, copper, zinc and iron, but these are usually of little consequence. Vanadium, if present, is often distilled from the feed stock of catalytic cracking processes, since it may spoil catalysis. The treatment of emulsion sludges by bio-treatment may lead to the concentration of metals and radioactive material, causing subsequent disposal problems. 

Fused Salt Electrolysis. Only light RE metals (La to Nd) can be produced by molten salt electrolysis because these have a relatively low melting point compared to those of medium and heavy RE metals. Deposition of an alloy with another metal, Zn for example, is an alternative. The feed is a mixture of anhydrous RE chlorides and fluorides. The materials from which the electrolysis cell is constmcted are of great importance because of the high reactivity of the rare-earth metals. Molybdenum, tungsten, tantalum, or alternatively iron with ceramic or graphite linings are used as cmcible materials. Carbon is frequently used as an anode material. 

If antimony and arsenic are present ia the feed, copper and iron react to form the respective antimonides and arsenides known as speiss (specific gravity 6.0). If it is preferred to remove copper ia a speiss layer, the sulfur ia the siater must be reduced and the addition of scrap iron may be necessary to encourage speiss formation. Matte and speiss are usually sent to a copper smelter for recovery of the metals. 

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