Ferro-alloy industry

Coke Production -Carbon black production -Petroleum catalytic cracking -Asphalt production -Aluminium smelting -Iron and steel sintering -Ferro-alloy industry... 

In the ferro-alloy industry the PAH emission is due to contact between hot metal and tarry products in electrodes and shutters. Only data for PAH emissions to water has been found for this source (29). However, assuming equal emission to water and air (50% efficiency in the wet scrubbers), this source has an emission factor of 10 g PAH per ton alloy. In a study in a Norwegian iron work, emissions to water were determined (29). PAH emission is due to the use of Soderberg electrodes. Making the same assumptions as above with the scrubber efficiency, the iron works emit 60 g PAH per ton produced iron. 

The suitability of gas absorption as a pollution control method is generally dependent on the following factors 1) availability of suitable solvent 2) required removal efficiency 3) pollutant concentration in the inlet vapor 4) capacity required for handling waste gas and, 5) recovery value of the pollutant(s) or the disposal cost of the unrecoverable solvent. Packed-bed scrubbers are typically used in the chemical, aluminum, coke and ferro-alloy, food and agriculture, and chromium electroplating industries. 

Stable oxides, such as those of chromium, vanadium and titanium cannot be reduced to the metal by carbon and the production of these metals, which have melting points above 2000 K, would lead to a refractory solid containing carbon. The co-reduction of the oxides with iron oxide leads to the formation of lower melting products, the ferro-alloys, and this process is successfully used in industrial production. Since these metals form such stable oxides and carbides, the process based on carbon reduction in a blast furnace would appear to be unsatisfactory, unless a product saturated with carbon is acceptable. This could not be decarburized by oxygen blowing without significant re-oxidation of the refractory metal. 

This industry sector includes pig iron manufacture manufacture of ferro-alloys from iron ore and from iron and steel scr< converting pig iron, scr iron, and scrap steel into steel hot rolling and cold finishing. Blast furnaces and by-product (or beehive) coke ovens are also included under this category, although these are almost nonexistent in the United States today. The complex and interdependent operations involved in a steel industry around the world can be listed as follows ... 

As in the case of vanadium, it is convenient to use the ferro alloy as the raw material for a chlorination process, since it is readily available for use in the steel industry. A typical analysis of ferroniobium is as follows ... 

Carbon refractories are used rrrainly in the alurttinum industry to line alrrrttina electrolytic tanks, as blast furnace hearths in the steel industry and in the ferro-alloy and pure sihcon indirstry as furnace lining and electrodes [DUM84]. These materials are used on accoimt of the following trrtique and exceptional properties of carbon ... 

The ecological and economic consequences of recovering 4500 lbs. per month of a 32% ferro-nickel alloy are impressive. This material can be saleable feedstock to industries producing wrought stainless steel, stainless steel castings, and high-nickel cast irons. Instead of a cost and liability, we now have a profit center. 

Although compounds of boron are widely used in industry, the element itself is seldom if ever required. Ferro-boron, an alloy with iron, has been used to a limited extent in the manufacture of boron steels. 

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