Silicon Dioxide Production and Application Essay

Introduction

The world is endowed with several natural resources, and silicon dioxide is one of them. Silicon dioxide is available in plenty, and it can easily be found in several parts of the world. Silicon dioxide is often called silica.

Because silicon dioxide is plentiful and valuable, many manufacturers use it as a prime raw material in manufacturing. Mountainous regions and sandy deserts are some of the areas where silicon dioxide is mostly found. Silicates form approximately sixty percent of the terrestrial crust. “The oxide of silicon includes sand, quartz, rock crystal, amethyst, agate, flint and opal” (Devine 34).

In 1907, Potter examined how silica and carbon reacted. His discovery marked the onset of commercial use of silicon. “Silica is a group IV metal oxide, which has good abrasion resistance, electrical insulation and a high thermal stability” (Devine 35). Apart from hydrogen fluoride, silicon cannot dissolve in any other acid.

Silicon Dioxide

When silicon comes into contact with oxygen, silicon dioxide forms. “Higher temperatures and alternative environments are used to grow well-controlled layers of silicon dioxide on silicon, for example, at temperatures between 600 and 1200 °C, using dry or wet oxidation with O₂ or H₂O, respectively” (Devine 36). SiO₂ symbol represents silicon dioxide. Strong covalent bonds are the ones that make silicon dioxide. The physical structure of silicon dioxide is properly defined.

Quartz crystalline is a good example of silica. “Apart from this, there are other distinct categories of silicon dioxide” (Devine 134). For instance, we have polymorphs and amorphous varieties of silicon. The distinctive attributes of silicon dioxide come about due to the oxygen ‘link’ bonds that are positioned between silicon atoms.

“Four oxygen atoms, that are electronegative, are arrayed at the corners of a tetrahedron around a central silicon atom” (Devine 89). Some bonds are long while others are quite short. These bonds do not possess specific lengths. They vary considerably in size between the distinct crystal structures. “Fibrous silica has a structure similar to that of SiS₂ with chains of edge-sharing SiO₄ tetrahedron” (Jutzi 107).

A-quartz is the only known stable kind of silicon that exists under natural conditions. Silicon dioxide is mostly physically found in this state. Natural quartz can have some colors due to the natural impurities that may be on it. When silica is dissolved, it can show unique physical attributes which resemble those examined in water.

Silicon production

Fused Quartz

Silicon is produced in numerous forms which include the following. Fused quartz is produced using natural quartz crystals. These crystals are melted by subjecting them to a high heat of approximately 2000 °C. The melting processes occur in electrically fused furnace.

Fused quartz appears in transparent form. It has both optical and thermal qualities. Hence, it serves as a semi conductor.” Scientists also use fused quartz in laboratories” (Zhang 276). Fused quartz possesses excellent ultraviolet, which enables it to give a better transmission that other types of glasses cannot offer. Optical lenses are also made using fused quartz.

In addition to these functions, precision mirror substrates are made using fused quartz because of its capacity of thermal extension is considerably low. Quartzite is the natural type quartz that exists as a metamorphic rock. High temperature combines together the quartz granules within the sandstone. Quartzite form of quartz does exist in an amorphous form. This can be used to differentiate it with fused quartz.

Fused Silica

“Fused silica is produced using high-purity silica sand as the feedstock, and is normally melted using an electric furnace, resulting in a material that is translucent or opaque” (Jutzi 211). Silica sand traps some air bubbles, hence, the final material becomes opaque. Substances with high silicon concentrations produce synthetic fused silica.

In this case, silicon is oxidized through a chemical gasification process that is primarily conducted using flame hydrolysis. Fumed silica is also made through the same channel. The only difference is that fumed silica comes in fine powder. It can be used as an adhesive, cosmetic, and in plastics. Besides this, pharmaceutical companies find it useful in their production processes.

Optical fibers manufacturers are dependent on fused silica, which is essential in optical fiber production. Halogen lamps are usually wrapped using fused silica. This is because fused silica has the ability to contain high temperatures since it is strong. Hence, it is appropriate for halogen lamps that need high temperature for producing high brightness. Photolithography requires projection masks, which in most cases are prepared using fused silicon. This is because of its excellent UV transparency.

“Fused silica as an industrial raw material is used to make various refractory shapes such as crucibles, trays, shrouds, and rollers for many high-temperature thermal processes including steelmaking, and glass manufacture” (Jutzi 345). Refractory shapes constructed using fused silica have the advantage of absorbing thermal shock. Moreover, they are chemically nonreactive to several compounds. Room heaters are in some cases covered with fused silica tubes.

Colloidal Silica

“These are suspensions of fine amorphous, nonporous, and typically spherical silica particles in liquid phase” (Devine 189). Colloidal silica can have a density of 2.3 g/cm³. Colloidal silica preparation undergoes multiple steps that include neutralization of an alkali-silicate.

Silica nuclei are made out of this process. “The colloidal suspension is stabilized by pH adjustment and then concentrated, usually by evaporation” (Devine 324). One of the drainage items in paper manufacturing is colloidal silica. It boosts the quantity of cationic starch in a paper. Cationic starch enhances the paper strength when it is in a dry form. Tablet lubrication can be done using colloidal silica. In some cases, colloidal silica can be useful in absorbing moisture.

Silica gel

It is produced synthetically using sodium silicate. Even if it is referred to as silica gel, it is in a granular state. This mineral can be easily encountered appearing inform of beads. Silica gel usually a company many packaged items, since it prevents damage that may arise from high moisture content. Therefore, it is a good desiccant. However, it can be really hazardous if consumed given that it is toxic.

Aero gel

Silica aero gel is a popular form of aero gel that has been researched on extensively. Silica nanofoam is recognized as a solid that has the lowest density globally. Infrared radiation can be easily attracted by silicon aero gel. “It has remarkable thermal insulation properties, since it has an extremely low thermal conductivity” (Jutzi 456).

It is arguably the best solid insulator with the lowest density. Its superior quality has earned it world recognition. Carbon aero gels are constructed using covalently bonded particles.

They are very permeable materials, with huge surface areas. Super capacitors can be prepared using carbon aero gels. “Depending on the density, carbon aero gels may be electrically conductive, making composite aero gel paper useful for electrodes in capacitors or deionization electrodes” (Zhang 278).

Aero gels are sometimes mistaken to be carbon nanotubes that are derived from chemical vapor through disposition mechanism. “These materials are not aero gels, however, since they do not have a monolithic internal structure and do not have the regular pore structure characteristic of aero gels” (Zhang 289). Alumina oxide can be applied in the making of aero gels. Such aero gels are termed alumina aero gels. Alumina aero gel can serve as catalysts. The sol-gel process is applied during production of aero gels.

Aero gels have the following functions. Skylights can be insulated using granular aero gels. Transparent silica aero gel is an essential substance for thermal insulation of buildings. This is because it mitigates thermal losses in structures. Its surface area is huge enough and this makes it suitable for wiping spills.

For example, space explorers usually clean dust in space craft using aero gel. In this case, it cleans surfaces through chemical absorption process. Moreover, this feature makes it a better catalyst. Paints and cosmetics can also be thickened using aero gels. In 2000, aero gel blankets became formally produced.

An aero gel bedspread has silica aero gel that is strengthened using yarns. “The mechanical and thermal properties of the product may be varied based upon the choice of reinforcing fibers, and the aero gel matrix included in the composite” (Zhang 300).

The US Navy is currently experimenting on aero gel undergarments, which they believe can offer thermal protection to captains. Games equipment such as tennis and squash rackets has partly been fabricated using aero gels. Aero gel is bio compatible hence it is helpful in delivery of drugs. Safety of aero gels is determined by products used in making it.

For instance, it can become carcinogenic in case the solid constituent exhibits such characteristics. Aero gels that are prepared with silica are never carcinogenic or toxic. Nonetheless, it can cause irritation especially on body organs that are exposed to it. Therefore, safety measures are imperative when using aero gels.

Quartz Glass

Normal cooling of silicon dioxide crystallizes it. However, when its temperature is rapidly lowered it solidifies and becomes a glass. Many polymorphs have similar atomic structures like those found in silica glass. Silicon glass can be distinguished from crystalline silica through analyzing the manner in which their tetrahedral units combine.

Silica glass is has tetrahedral networks that appear only ones. In this case, an oxygen atom only bonds with a tetrahedral that is located close to it. “Although there is no long range periodicity in the glassy network there remains significant ordering at length scales well beyond the silicon dioxide bond length” (Zhang 532).

Manufacture of Glass

Ancient civilizations are associated with the origin of glass production and usage. For instance, classical inhabitants of the Roman Empire and Egypt used glass items. The technique was later adopted by subsequent cultures that emerged after the end of the ancient period.

Glass is a material that is solid and amorphous. Common features of glass are its brittle and transparent nature. Glasses used domestically and commercially in construction are primarily made using silica. Glass is termed more broadly in science. In scientific context, glass encompasses solid objects, which have structures that are not crystalline.

When such solids are melted to liquid form, they also demonstrate a glass transition. This implies that a range of substances can be employed in making glass.

For example, molecular liquids, metal alloys, and polymers are applicable in the process. Some glasses are produced without the silica component. This gives them some attributes that makes them significant for technical applications. For example, fiber optics relies on fluoride and borate forms of glass.

“There are three classes of components for oxide glasses: network formers, intermediates, and modifiers” (Jutzi 523). Glass ceramics exhibit some characteristics that resemble those of non-crystalline glasses. They are first prepared as normal glasses. After that, they undergo minor crystallization that is done using heat. For example, white ware mostly has amorphous and crystalline parts.

Portland Cement Production

Portland cement is in common usage in construction. This is because of the ingredients used in making it. Portland cement is also termed as hydraulic cement.

“The raw materials for Portland cement production are a mixture of minerals containing calcium oxide, silicon oxide, aluminum oxide, ferric oxide, and magnesium oxide, as fine powder in the ‘Dry process’ or in the form of a slurry in the ‘Wet process” (Devine 298).

Silicon and Food Production

Food partly comprises of silicon. This means that human beings also use silicon. In human body, bone development is enhanced by silicon. Therefore, silicon rich foods, like nuts, are highly encouraged in diet. Silicon also facilitates elimination of aluminum constituents.

As such, Alzheimer’s disease cannot affect somebody easily. Silicon is found in natural fruits. Hence, it is better to eat them. Apart from eating fruits, as potential source of silicon, we can also add silicon directly in food. However, if it is misused it can be exceptionally harmful to one’s wellbeing.

“Silica is a common additive in the production of foods, where it is used primarily as a flow agent in powdered foods, or to absorb water in hygroscopic applications” (Devine 461). For example, colloidal silicon can purify wines. Diatomaceous earth is a significant chemical that helps in purification and eradication of pests. Silica is the chief composition of this chemical. Rice husk ash is also made up of silicon dioxide. This chemical is usually applied during filtration and also in cement production.

Electronics Industry

Microelectronics is a department of electronics. Microelectronics deals with production of tiny electronic components. Semi conductors are among the prime materials applied in making microelectronic gargets. “Thin films of silica grown on silicon wafers via thermal oxidation methods can be quite beneficial in microelectronics, where they act as electric insulators with high chemical stability” (Zhang 355).

They also store charge when they are used in electric connections. Apart from this, current can be blocked and its flow can also be regulated using silica. “Circuit Boards and piezoelectric gadgets use fused silica because it has extremely good dielectric and insulating properties” (Jutzi 521).

Refractory gadgets are mostly constructed using silica sand. In this case, Bayer alumina is used together with silica sand. When they react chemically, they produce synthetic mullite.

These refractory slabs act as coating materials for furnace chambers. In addition to this, mullite contains a superb creep resistance. “The high shock resistant refractory material silicon carbide is produced by the reaction of silica sand with coke” (Jutzi 145). “Silica is also used in the production of AZS by fusion casting, which used the glass industry” (Jutzi 145).

Health Effects

Most of the chemical compositions of silicon are dangerous particularly to human health. For instance, if a person inhales crystalline silica continuously, he or she risks having dangerous complications such as cancer and bronchitis. This is because silicon dust clogs the lungs and entire respiratory system.

Therefore, if silicon is poorly managed, where it is used commercially, it can be a serious occupational hazard. As such laws should be reinforced with an aim of curbing misuse or poor disposal of silicon products. Silicon can also lead to tooth wear. This happens when somebody’s teeth comes into contact with substances with high silicon concentration. For example, if domestic water has traces of silicon. To some extent, grazing animals also benefit from plants that contain high silica.

Conclusion

“Silicon is arguably one of the most precious natural minerals that are readily available” (Jutzi 76). Because silicon dioxide is plentiful and valuable, many manufacturers use it as a prime raw material in manufacturing. Strong covalent bonds are the ones that make silicon dioxide. The physical structure of silicon dioxide is properly defined.

Quartz crystalline is a good example of silica. “Silica is manufactured in several forms including fused quartz, crystal, fumed silicacolloidal silica, silica gel, and aero gel” (Devine 256).

The distinctive attributes of silicon dioxide come about due to the oxygen ‘link’ bonds that are positioned between silicon atoms.

“Silica is used primarily in the production of glass, circuit boards, piezoelectric, semi conductors, and refractory materials” (Jutzi 388). Even though silicon is useful, it can be exceptionally dangerous if consumed since it is poisonous. This is because many silicon substances are extremely toxic.

Works Cited

Devine, Robert. Structure and Imperfections in Amorphous and Crystalline Silicon Dioxide. New York: Wiley, 2000.

Jutzi, Peter. Silicon Chemistry: From the Atom to Extended Systems. New York: Wiley, 2003.

Zhang, Xiaoge Gregory. Electrochemistry of Silicon and Its Oxide. London: Springer, 2001.