Hot metal desulfurization

During hot metal desulfurization, used to remove or alter sulfur compounds in the hot metal, the exhaust gases are found to bear particulate matter. Emissions may also result from slag handling. Sulfur dioxide is formed when the sulfur in the slag is exposed to air. The presence of moisture can... 

They firmly selected the low sulfur route and embarked in heavy investments for hot metal desulfurization equipment and later in steel desulfurization ( ). Until 1973, however, the sulfur levels achieved by hot metal desulfurization did not help the final sulfur content because of the contaminating effect of cooling scrap in the Basic Oxygen Furnace (BOF), except in Japan where... 

The hot metal desulfurization slag (dekish slag) constitutes a promissing material for treatment of some industrial wastewaters. 

There are two part experiments of this new desulfurizer, one is Mg vapor production experiment the other one is hot metal desulfurization experiment. The materials in the two experiments are the same. Dolomite and 75ferrosilicon were used. The chemical chemical composition is shown in Table 1 and 2. 

Zhang Ting-an et al., Study of MgO-based Desulfurizer In Hot Metal Desulfurization. Journal of Iron and Steel Research (international), 18,(S2)(2011), 87-90. 

Diaz-Somoano, M., L6pez-Ant6n, M.A. and Martfnez-Tarazona, M.R. (2004) Retention of arsenic and selenium during hot gas desulfurization using metal oxide sorbents. Energy and Fuels, 18(5), 1238-42. 

In this work the feasibility of hot iron desulfurization slag application as a precipitation reagent for wastewater soluble heavy metals was studied. Experiments were performed on both slimulated wastewater containing 50 mg/L zinz in tap... 

Thus, the tendency is to advocate the use of dry lime scrubbing systems thereby producing a waste stream that can be handled by conventional fly ash removal procedures. There are also dry processes, such as the metal oxide processes, in which sulfur dioxide can be removed from gas streams by reaction with a metal oxide. These processes, which are able to operate at high temperatures (approximately dOO C [TSO F]), are suitable for hot gas desulfurization without an energy-wasteful cooUng step. The metal oxides can usually be regenerated by aerial oxidation to convert any metal sulfide(s) back to the oxide(s) or by the use of a mixture of hydrogen and steam. 

As previously discussed in more detail, there are two general types of hot gas desulfurization systems direct injection of limestone with the gas into the gasifier, and metal oxides. The limestone systems suffer from lower sulfur removal/recovery efficiency and the generation of large amounts of reactive solid waste material. The metal oxide systems are more complex, and generate a relatively dilute SO2 stream that must be converted to sulfur or sulftiric acid. Two other potential problems with both types of hot desulfurization systems are NO, and trace components. 

Secondly, the passivated magnesium which is required by industrial produce is expensive. For example, in North America, the average price of magnesium for desulfurization is 1.5 dollars per pound. To treat 1 ton hot metal needs 300-500g of magnesium, which will cost 1.0-1.5 dollars. ... 

Gupta, R. P., and Gasper-Galvin, L. D., 1991, Screening of Supported Metal Oxides for Hot-Gas Desulfurization, presented at the 1991 AIChE Annual Meeting, Los Angeles, CA, Nov. 17-21. 

Desulfurization of hot iron by addition of calcium carbide leads to formation of a slag containing calcium sulfide and hydroxide as well as substantial amount of iron oxides. This slag is completely different than other metalurgical slags and may be effectively used for treatment of various acidic dr neutral wastewater containing heavy metal cations by hydroxide/sulfide precipitation, and, by removal of several components from wastewater by sorption and other interactions with iron oxides. 

Fig. 4. Staple fiber washing sequence 1, a hot acid wash (2% H2SO4 at 90°C) decomposes and washes out most of the insoluble zinc salts. This wash completes the regeneration of xanthate and removes as much sulfur as possible in the form of recoverable CS2 and H2S 2, an alkaline sodium sulfide desulfurization bath solubilizes sulfurous by-products and converts them into easily removed sulfides 3, a sulfide wash to remove the sulfides created in bath 2 4, a bleach bath (optional) uses very dilute hypochlorite or peroxide to improve fiber whiteness 5, a dilute acid or sour bath removes any remaining traces of metal ions and guarantees that any residual bleaching chemicals are destroyed 6, a controlled-pH freshwater final wash removes the last traces of acid and salt prior to drsdng and 7, a finish bath gives the fiber a soft handle for easy drying and subsequent processing.

Metal Oxide Powders (MOP) Examples ZnO, MgO, AI2O3 Zinc ferrite ZnFc204 Removal of NO, from exhaust gas Hot exhaust gas desulfurization [ 1.41 ]... 

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