Ferrosilikon ve Silikon Teknolojisi

Sıvı halde silikon, termal ve elektrik iletkenliği ile ilgili metalik özelliklere sahiptir, ancak katı halde yarı iletkendir ve metaloid olarak adlandırılır. Renk ve yansımadaki görsel benzerlikleri nedeniyle, genellikle yanıltıcı bir şekilde metal olarak anılır. Ayrıca üretim sürecinde silikon, manganez alaşımları ve krom alaşımları gibi metal üretimi için kullanılan ekipmanlarda üretilebilir ve bu nedenle bu alaşımlar ile gruplandırılır.

01/05/2023
20 dakika

In the liquid state, silicon has metallic properties regarding thermal and electrical conductivity, but in the solid state, it is a semiconductor and is called a metalloid. Due to its visual similarities in color and reflectance, it is often, misleadingly, referred to as a metal. Also when it comes to the production process, silicon may be produced in equipment used for metals production, such as manganese alloys and chromium alloys, and thus it is grouped with these alloys.

INTRODUCTION TO SILICON AND ITS FERROALLOYS

In the liquid state, silicon has metallic properties regarding thermal and electrical conductivity, but in the solid state, it is a semiconductor and is called a metalloid. Due to its visual similarities in color and reflectance, it is often, misleadingly, referred to as a metal. Also when it comes to the production process, silicon may be produced in equipment used for metals production, such as manganese alloys and chromium alloys, and thus it is grouped with these alloys.
Before the 19th century, all elements discovered were produced by reduc- tion with either hydrogen or carbon, but the later discovery of electrolysis has
allowed the extraction of potassium, sodium, calcium, barium, strontium, cadmium, and aluminum. In 1824, silicon was produced by the Swedish chemist Jo¨ ns Jacob Berzelius, and he named the new material “silicium.” As this material was closer in properties to boron and carbon than materials like magnesium and calcium, the Scottish chemist Thomas Thomson renamed it “silicon” some years later. In the literature, both names are still in common use in some countries.
The development of the industrial process of silicon production took almost a century (Schei et al., 1998; Vishu et al., 2005). With the development of the electric arc furnace by Paul He´roult, the first commercial plant was started in the United States in 1907, where high silicon Ferrosilicon and silicon could be produced industrially. Frank Tone of Carborundum Co. was the first to commercialize the production of silicon. In the 1920s, silicon use in aluminum alloying increased steadily. In the 1930s, silicon application in chemicals and silicones increased, and the next boost for silicon came after the 1950s for photovoltaic applications, followed by the modern-day silicon demand in electronics. To be used as a semiconductor, silicon needs to be pure, and hence the metallurgical grade Si (MG-Si) must be further refined to fulfill require- ments. Whereas MG-Si usually has 98.5% to 99.5% Si, the impurity content in photovoltaic devices, such as solar cells, must be in the ppm level and in electronic devices the impurity content must be in the ppb level. The most used refining method for both products is the Siemens process, where the Si is transformed to silicon–chlorine gases, which are distilled and then reduced to silicon.
The development of Ferrosilicon technology corresponded with progress in the steel industry. In the 19th century, low silicon Ferroalloys (~20% Si), known as silvery pig iron, were produced in blast furnaces, but since the 1920s all production has been moved to submerged arc electric furnaces, as they alone offer the only possibility of high silicon Ferroalloys smelting.

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