PRODUCTS

DESULFURIZERS.

Desulfurizers are synthetic slags which are added to the ladle on their arrival at the Refinery Furnace when the chemical composition and temperature start to be adjusted, in order to attain an efficient desulfurization of previously deoxidized steel.

The extraction of S by means of slag is the only useable reaction to date. The reaction may be used according to the following:

(CaO) + S à Sca + O.

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Thus, desulfurization is the interchange of Oxygen and Sulfur between metal and slag. Affecting the efficiency of the process are factors such as the initial sulfur content in the steel, slag volume, its degree of saturation in CaO and MgO, the abutting surface with the steel and the degree of shaking, (generally with Argon). For steel workers, the most difficult step in the process of desulfurization is preventing the furnace slag from entering the ladle. The slag in the furnace allows a slow, but steady transfer of oxygen from the slag to the steel. All of this generates impure oxides and limits or prevents the desulfurization reaction. At the end of this process the sum of the % of FeO plus the % of MnO in the slag should never be exceed l 1 %.

DEOXIDIZERS.

Deoxidizers are products that are added to the ladle when dumping. The purpose of the rust removal operation is to eliminate all or part of the dissolved oxygen produced during the stages of Fusion, Refining and Electric Furnace Heating (nowadays quantities of around 18 -30 m3 of O2 are blasted) taking into account the structure and physical state of cleanliness that is desired in the charts of the finished product.

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From the very beginning, Sidercal Minerales has tried to concentrate all its R+D efforts on this stage of the metallurgy in the ladle. Therefore, while traditionally this process was carried out by applying a series of elements, Sidercal began to investigate the application of certain compounds, studying all the possibilities that would allow for a new focus of fusion and dumping technology in the Electric Arc Furnace.

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Deoxidizers are compounds composed of elements that have a great affinity for O2, Ti, Si, C and Mn, which may be added in the form of more or less complex alloys. When several rust removal elements are simultaneously introduced into liquid steel, the inclusions that precipitate may contain several oxides, each of which may present thermodynamic activity in the slag that is lower than the unit.

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This means that a group of deoxidizers together will always be more efficient than each one taken separately. Moreover, the combination of several deoxidizing agents act on the composition of residual inclusions. A general rule in steelmaking is that if the product of deoxidization is a complex oxide, then the dissolved oxygen will be lower than if the deoxidization product is a simple oxide.

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Our range of deoxidizers contains a series of elements that have a great affinity for oxygen; they produce slag; maintain the appropriate basicity and fluidity, make deoxidization more extensive and protect the coating of the ladle.

FLUXES.

To attain a good sulfurization, it is necessary to have a very basic slag with a ratio of CaO/SiO2 greater than 2. However, this type of slag has a very high fusion point which means that alone, it has a weak capacity to capture sulfurs. To increase this capacity, it is essential to add some type of fluxing agent that will lower this fusion point. On occasion, the combination of several fluxing agents helps attain this objective much more quickly.

In addition to the fusion point, the viscosity of the slag is very important in terms of how it behaves during fusion.

A low fusion point will allow us to form the slag easily and quickly, and therefore at a low energy cost. If it forms rapidly, the electric arc will be protected from the very beginning and therefore, there will be a minor loss of calories, leading to a high thermal yield during the refining and heating stages in the Furnace in the ladle.

Moreover, fluid slag will have a high capacity to reduce and capture inclusions, which is another one of the aims of the slag to produce clean steel.

BASE METAL MIXTURES.

The chemical industry has a long history of evaluating secondary material and some of these have given rise to entire branches of activity. In his well documented work on the petrochemical industry, Peter Speitz, goes so far as to say that the driving force behind the evolution of industrial chemistry has always been more related to the availability of stocks of “useless” material than to the technological process or market demand.

The systematic research conducted by German chemists to evaluate different products generated in large quantities in gas plants has led to modern organic chemistry. The synthetic dyes with an aniline base, developed since 1860, were almost all derived from carbon-based chemical products.

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Another significant example is as follows. In the 1930s, the availability of reactive hydrocarbons produced in the refineries, as a consequence of the expansion of the automotive industry, in just a few decades, has given rise to the petrochemical industry. In fact, up until very recently, natural gas was considered to be simply a byproduct of oil drilling. And although, it has been used for a long time as a fuel to feed the refining process and for light, most of this gas was simply burned off in the large torches of the oil wells, a practice which is still common today in some parts of the world. Natural gas did not have an important chemical use until World War II, when it became a base material to produce ethylene and later, butadiene, -fundamental ingredients in synthetic rubber.

So, materials with a generic composition, a series of metals with their oxidized species, hold an enormous potential for recycling in different industrial processes, since they are not used up in the process that they originated from.

The first difficulty in recycling these materials is their characterization, which can only be solved by delving deep into the subject of chemical speciation.

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Sidercal Minerales has developed a series of products that can be used in different metallurgic proceses in order to save on energy, stabilize processes, improve the properties of the finished product, etc. which has also allowed us to set up industrial trophic networks that are no less complex than those established in the natural ecosystems and which eventually create a true industrial metabolism.

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