Aktywność

“The Features And Applications Of Silica Bricks
Silica bricks is a refractory product regarding silicon dioxide as a main component and its content is above 93%. It is made of quartzite as a raw material, and a small amount of mineralizer is added to be fired at a high temperature. It belongs to acidic refractory,which has strong resistance to acid slag erosion, but it is strongly eroded by alkaline slag. It is easily destroyed by oxides containing Al2O3, K2O and Na2O,but it has good resistance to oxides such as CaO, FeO and Fe2O3. The mineral composition of silica brick is a coexisting multiphase structure such as tridymite, cristobalite, a small amount of residual quartz, and a glass formed at a high temperature. The higher deformation temperature of the load is the excellent characteristic of silica brick. Its melting point is close to the melting point of the quartz and cristobalite (1670℃, 1713℃) and fluctuating between 1640℃ and 1680℃. After re-calcining, silica bricks will undergo irreversible volume expansion due to the continued conversion of the quartz remaining in the bricks. In the interval from 300℃ to near the melting point, the volume of silica brick is stable and it will have a total volume expansion of about 1.5% to 2.2% when heated to 1450℃. However, this expansion will make the joints tight and ensure that the masonry has good air tightness and structural strength. Meanwhile, the biggest disadvantage of silica brick is its low thermal shock stability, followed by low refractoriness (generally 1690℃~1730℃), which limits its application range. Silica bricks are mainly used in coke ovens, glass melting furnaces, acid steelmaking furnaces and other thermal equipment.

Silica Bricks For Coke Ovens

The modern coke oven is a large-scale thermal equipment built of tens of thousands of tons, nearly thousands brick-type refractory materials, which the amount of silica bricks account for 60%~70%. The silica brick for coke oven is mainly composed of tridymite, which is mainly used for building regenerator walls, chutes, combustion chambers, carbonization chambers and furnace roofs of coke ovens. Silica bricks for coke ovens mainly have the characteristics of high load softening temperature, high thermal conductivity, good thermal shock resistance, and volume stability at high temperatures.

The Importance of Refractory Brick
Wood ovens are ideal for retaining heat to cook an amazing meal, but how do the ovens stand such high temperatures and why is it important? These bricks are made from a special type of ceramic which can withstand high temperatures without damage. A typical brick could start to break apart at 1200 degrees Fahrenheit (~ 649 degrees Celsius), but a refractory brick will handle heat up to 1800 degrees Fahrenheit (~982 degrees Celsius). This removes any of the stress that may come from heating up the wood oven, and you’ll be able to safely turn the temperature up knowing that the bricks can handle the heat. Refractory bricks are also energy efficient. This is because refractory bricks have low thermal conductivity, meaning that they start absorbing the heat quickly, so there’s no waste when preparing your meal. The bricks coupled with convection design, quality stainless steel, and outstanding ventilation allow the Alfa to retain heat for your perfect cook. Not only are refractory bricks tough against the heat, but they can also handle the wear-and-tear of cooking. You don’t have to worry about delicately touching your tools to the surface of an oven with refractory bricks. They are sturdy and resistance to abrasion – not only durable but long lasting. Refractory bricks often line the walls of industrial furnaces and incinerators, so you know they can take the heat and you can focus on cooking the perfect pizza or meal.

Silicon Carbide (SiC): The Future of Power?
Silicon carbide products, also known as SiC, is a semiconductor base material that consists of pure silicon and pure carbon. You can dope SiC with nitrogen or phosphorus to form an n-type semiconductor or dope it with beryllium, boron, aluminum, or gallium to form a p-type semiconductor. While many varieties and purities of silicon carbide exist, semiconductor-grade quality silicon carbide has only surfaced for utilization in the last few decades.

How to Create Silicon Carbide

The simplest silicon carbide manufacturing method involves melting silica sand and carbon, such as coal, at high temperatures―up to 2500 degrees Celsius. Darker, more common versions of silicon carbide often include iron and carbon impurities, but pure SiC crystals are colorless and form when silicon carbide sublimes at 2700 degrees Celsius. Once heated, these crystals deposit onto graphite at a cooler temperature in a process known as the Lely method.

– Chemical vapor deposition: Alternatively, manufacturers grow cubic SiC using chemical vapor deposition, which is commonly used in carbon-based synthesis processes and used in the semiconductor industry. In this method, a specialized chemical blend of gases enters a vacuum environment and combines before depositing onto a substrate. Both methods of silicon carbide wafer production require vast amounts of energy, equipment, and knowledge to be successful.

How is Silicon Carbide Useful?

Historically, manufacturers use silicon carbide in high-temperature settings for devices such as bearings, heating machinery components, car brakes, and even knife sharpening tools. In electronics and semiconductor applications, SiC’s advantage main advantages are:

– High thermal conductivity of 120-270 W/mK

– Low coefficient of thermal expansion of 4.0×10^-6/°C

– High maximum current density

These three characteristics combined give SiC excellent electrical conductivity, especially when compared to silicon, SiC’s more popular cousin. SiC’s material characteristics make it highly advantageous for high power applications where high current, high temperatures, and high thermal conductivity are required. In recent years, SiC has become a key player in the semiconductor industry, powering MOSFETs, Schottky diodes, and power modules for use in high-power, high-efficiency applications. While more expensive than silicon MOSFETs, which are typically limited to breakdown voltages at 900V, SiC allows for voltage thresholds at nearly 10kV. SiC also has very low switching losses and can support high operating frequencies, which allows it to achieve currently unbeatable efficiencies, especially in applications that operate at over 600 volts. With proper implementation, SiC devices can reduce converter and inverter system losses by nearly 50%, size by 300%, and overall system cost by 20%. This reduction in overall system size lends SiC the ability to be extremely useful in weight and space-sensitive applications.

What is Sintered Ceramic?
Sintered ceramic, or sintered stone, is man-made stone that’s formed by grinding natural materials such as silica, quartz, feldspars, clay and mineral pigments down to small particles that are compacted using heat and pressure without melting to the point of liquefaction to form one solid slab. In addition to sintered stone and man-made stone, sintered ceramic is also referred to as artificial stone or ultra-compact surface. Simply put, the process of creating sintered ceramic is an accelerated version of what happens in nature over millions of years to create natural stone. The mix of powdered or sand materials determines strength, hardness, chemical stability and workability. The ingredients are processed under extreme heat and a pressure of more than the weight of the Eiffel Tower. The solid slab is fired in the kiln at 1200°C to dry out, and in doing so is baked and the particles are fused together.

As a result of being made from natural materials, the slab is resistant to the sun’s ultraviolet (UV) rays. Additionally, because it’s put under such pressure and heat, sintered ceramic is also highly resistant to scratching, extreme temperatures, water and stains.That’s what makes Ceramitex a sintered ceramic facade system that simply outperforms. Meeting or exceeding industry code standards throughout North America, the Ceramitex system is made up of large-format, ultra-strong cladding panels that are lightweight and highly durable; they’re water and graffiti proof while also being resistant to extreme weather and temperatures, scratches and high-traffic abrasion.

But durability is just part of what makes Ceramitex the perfect sintered ceramic panel facade system for your next project. Thanks to Elemex’s innovative Unity integrated attachment technology, Ceramitex is easy to install and can be fabricated to an architect’s exacting specifications for limitless design flexibility. Elemex’s sintered ceramic facade cladding comes in a variety of colors and finishes, plus the system allows the ability to create large, mitered returns that give a striking dimensional appearance to any returning edge, a unique feature of Ceramitex. Ceramitex sintered ceramic facade systems, and all Elemex architectural facade systems, are supported by the 360° Advantage, which guarantees that Elemex will be there to support you through the entirety of your project – from concept to completion.

The sedimentology of flint clay
Flint clay is kaolinitic mudstone that distinctively differs from widely known shale in lithology, genesis, and economic uses. Flint clay is described as a fine-grained, compact, non-fissile, essentially monomineralic kaolinitic rock that breaks with a conchoidal (“”flinty””) fracture, has almost no natural plasticity, and resists slaking. It is valuable as a refractory raw material but is also geologically interesting because of its sedimentology, unique in some respects, which is emphasized in this report. Although not particularly abundant in sedimentary rocks, flint clay is worldwide in geographic occurrence. Flint clay is interpreted as having been a product of very early diagenesis–a diagenesis that occurred mainly during accumulation of parent aluminum silicate material rather than dominantly after its deposition and consolidation, the classical concept of diagenesis. The depositional environment typically was non-marine, paludal or fluviatile. at a time of local crustal stability, within the environment and climate typical of Coal Measures. Diagenetic reactions producing flint clay were dominated by desilication, partial removal of iron, alkaline and alkali earths producing a mud that had the composition of kaolin, followed by crystallization or recrystallization of the “”digested”” sediment into interlocking crystals of kaolinite which is rather well-ordered crystallographically. Where leaching of silica and potassium did not progress far, some illite may have persisted with the kaolinite.

http://www.runjinrefractories.com/”