forming a strong oxide that, compared to pure oxygen, will reduce the steel's strength and qualities by a lesser amount. The chemical equation for deoxidization is represented by: where n and m are coefficients, D is the deoxidizing agent, and O is oxygen. Thus, the chemical equilibrium equation involved is: where aox is the activity, or concentration, of the oxide in the steel, aD is the activity of the deoxidizing agent, and aO is the activity of the oxygen. An increase in the equilibrium constant Keq will cause an increase in aox, and thus more of the oxide product. Keq can be manipulated by the steel temperature via the following equation: where AD and BD are parameters specific to different deoxidizers and T is the temperature in K°. Below are the values for certain deoxidizers at a temperature of 1873 K°. Below is a list of commonly used metallic deoxidizers: Ferrosilicon, ferromanganese, calcium silicide - used in steelmaking in production of carbon steels, stainless steels, and other ferrous alloys Manganese - used in steelmaking Silicon carbide, calcium carbide - used as ladle deoxidizer in steel production Aluminum dross - also a ladle deoxidizer, used in secondary steelmaking Calcium - used as a deoxidizer, desulfurizer, or decarbonizer for ferrous and non-ferrous alloys Titanium - used as a deoxidizer for steels Phosphorus, copper(I) phosphide - used in production of oxygen-free copper Calcium hexaboride - used in production of oxygen-free copper, yields higher conductivity copper than phosphorus-deoxidized Yttrium - used to deoxidize vanadium and other non-ferrous metals Zirconium Magnesium Carbon Tungsten Vacuum deoxidation Vacuum deoxidation is a method which involves using a vacuum to remove impurities. A portion of the carbon and oxygen in steel will react, forming carbon monoxide. CO gas will float up to the top of the liquid steel and be removed by a vacuum system. As the chemical reaction involved in vacuum deoxidation is: the reaction between carbon and oxygen is represented by the following chemical equilibrium equation: where PCO is the partial pressure of the carbon monoxide formed. Decreasing the oxygen activity(aO) will result in a higher equilibrium constant, thus more product, CO. To achieve this, subjecting the pool of steel to vacuum treatment decreases the value of PCO, allowing for more CO gas to be produced. Diffusion deoxidation This method relies on the idea that deoxidation of slag will lead to the deoxidation of steel. The chemical