How to Make Silicon Carbide

Silicon carbide, an extremely strong mechanical material used across numerous industrial applications, is increasingly being utilized. Its hardness surpasses that of its rival tungsten carbide.

Most silicon carbide is produced using the Acheson Process, created accidentally by Edward Goodrich Acheson while trying to produce synthetic diamonds. It is the easiest and simplest way of producing SiC.

The Acheson Process

Silicon carbide production worldwide relies heavily on an age-old technique known as the Acheson Process. Under this method, pure silica sand and coke are combined at high temperature conditions in an electric furnace before reacting with each other to form silicon carbide.

Silicon carbide (SiC) is an outstanding ceramic material. Its hardness ranks second only to diamond and cubic boron nitride, making it highly resistant to both wear and corrosion. Furthermore, SiC displays excellent high-temperature load bearing strength as well as thermal shock resistance – plus chemically inertness towards alkalies and acids.

Silicon carbide can be produced through high-temperature reactions involving silicon on carbon precursors such as coal or petroleum coke, while alternatively silicon sources may be reduced through carbon monoxide reduction.

Under the Acheson Process, reaction mixtures are packed around an electrical resistor in a special furnace, while an electrical current passes through it, heating it to high temperatures necessary for SiC synthesis. Temperature measurements are taken via optical pyrometer means placed along various walls of the furnace.

As silicon and carbon react, gasses are produced that need to be expelled from the reaction mass. To prevent volatile compounds from forming, increasing overall temperature as much as possible while having an ample volume of reaction space is desirable; to do this, coverage means must be positioned over top of the reaction mixture so as to cover at least part of its surface in an Acheson furnace. The present invention provides a method for accomplishing this.

These cover means are outfitted with low-pressure argon atmospheres to facilitate gaseous reactions occurring within the reaction zone and neutralize them effectively, helping prevent formation of volatile compounds which are hard to remove from the reaction mass.

Covers should also feature high air permeability to enable reaction gases to escape through them without being lost to surrounding refractories and increase their effectiveness and make treating gaseous products from silicon carbide production easier.

Chemical Reactions

Silicon carbide (SiC) is one of the hardest substances known, making it ideal for applications such as abrasive sandpapers, cutting tools, grinding wheels and metal cutting applications. Furthermore, SiC can be found across a range of manufacturing industries such as metallurgy and refractories; however, SiC cannot be produced naturally and must instead be synthesized through chemical processes.

The most widely-used method for producing silicon carbide is known as the Acheson reaction, named for American chemist Edward Goodrich Acheson. In this process, silica sand and carbon in the form of ground coke is mixed together and then placed around an electric resistance-type furnace in an electric resistance furnace before an electric current passes through and causes chemical reaction that transforms silicon and carbon into silicon carbide crystals.

Lely reaction is another way of creating silicon carbide; powdered silicon and carbon are combined and placed into a graphite crucible before heating to high temperatures to produce silicon carbide, which then sublimes onto a graphite rod in the center of the crucible and forms pure crystals that can then be separated using centrifuge or other means of separation.

Chemical vapor deposition offers another method for creating cubic silicon carbide wafers; however, this approach tends to be much more costly and often utilized for research and development of electronic components.

No matter the production method, both reactions produce reaction-bonded silicon carbide (RB-SiC). RB-SiC is then used to make products such as refractory grade silicon carbide grit, ceramic nozzles, insulators, electrodes, wear-resistant coatings and wear-resistant coatings; an excellent alternative to sintered SiC when corrosion resistance or hardness are not a requirement. Washington Mills offers multiple chemical compositions and sizes of RB-SiC that can meet various industries including, but not limited to:

Physical Reactions

Silicon carbide (SiC) is a chemical compound made of silicon and carbon that exhibits exceptional mechanical properties that make it useful in applications ranging from abrasives and cutting tools to diamond simulants and gemstones. While SiC naturally occurs as the rare mineral known as moissanite, most commercial silicon carbide production takes place synthetically.

The Acheson Process is the standard method for producing silicon carbide. This procedure involves heating a mixture of silica sand and coke at high temperatures in an electric resistance furnace known as an Acheson graphite furnace to cause reactions between silica and carbon, forming crystalline masses of SiC that can either be powderized into powder form or formed into balls for further cutting by diamond-tipped blades.

This process must take place in an inert atmosphere such as argon to protect the reactants from contamination by oxygen and other impurities, before heating to produce pure cubic silicon carbide.

Pure titanium dioxide appears as a light yellow to green-to-bluish-black powder that sublimates at 2700 degC and has a density of 3.21 g cm-3. However, it remains insoluble in water but soluble with alkalis or iron molten at elevated temperatures.

Silicon carbide’s high melting point, low viscosity and thermal conductivity make it the ideal material for producing refractory products such as bricks, tiles and blocks. Furthermore, silicon carbide is used in electrical devices like spark plugs and insulators.

Silicon carbide is one of the primary drivers behind electric vehicles’ projected dominance of automotive markets, as it reduces dependence on active cooling systems that add weight, cost and complexity.

However, as with any technology, there is always room for improvement. The current production process for silicon carbide requires extensive labor and waste production that could be minimized through increased efficiency of production methods – for instance using more effective furnace designs could significantly lower energy usage by up to 50% and improve productivity overall.

Heat Treatment

Carborundum (or “carbo,” for short) is a hard chemical compound composed of silicon and carbon found in nature as moissanite gemstone. Since 1893 it has been mass produced as powder using the Lely method, and as single crystals using sintering. Sintering produces ceramics used in applications requiring high endurance such as car brakes and bulletproof vests as well as being an abrasive substance. Carbo can also be found used as an abrasive.

Industry-grade silicon carbide is manufactured via electric furnace processes using glass sand, low ash coal or high-grade petroleum coke as starting materials. Even when starting with high-grade starting materials, however, this process tends to produce impure material containing aluminium, magnesium, calcium, graphite and free silicon; these impurities may be removed by washing in hot water bath or chemical precipitation before being machined and sintered under vacuum to produce dark brown to black powdered silicon carbide powder with rainbow-like luster!

This invention describes a process for producing pure cubic silicon carbide, an extremely useful semiconductor material which serves both semiconducting and electroluminescent functions. To produce it, sugar solutions are mixed with silicon tetrachloride until gel formation occurs, then dried out to decompose sugar crystals before heating in an atmosphere (preferably argon) to create silicon carbide.

The inventor states that for optimal results, the final product should contain three silicon atoms for every carbon atom. This ratio can be altered by altering the sugar concentration in solution. Once silicon carbide has formed, it must then be crushed and ground down to produce desired particle sizes using methods such as grinding, sieving, centrifuging and blasting before further purifying using an electric furnace in vacuum or nonreactive atmosphere to produce highly valuable silicon carbide products. This process provides an efficient and economical means of producing highly valuable silicon carbide products.