Sammansättning av eldfast rammande massa
◉ Rå material och förhållande
Eldfast rammningsmaterial, ett granulärt och pulveriserat material som är noggrant tillverkat av eldfasta råvaror, innehåller ofta en lämplig mängd bindemedel och är lös efter rimlig gradering och blandning . Dess konstruktionsmetod kräver vanligtvis stark rammning, liknande torra hårda roller, men vissa produkter har inte självhärdande bindemedel .}
När vi diskuterar sammansättningen av rammningsmaterial, fann vi att granulära och pulverformiga material står för en stor andel, medan bindemedel och andra ingredienser står för en liten andel, och vissa produkter till och med är helt sammansatta av granulära och pulverformiga material .. requirements. Since ramming materials are often used in environments where they are in direct contact with melts, the raw materials must have high volume stability, density and corrosion resistance, and are usually made of high-temperature sintered or molten materials. In addition, in some applications, such as ramming materials in induction circuits, they must also have insulation properties.
Val av bindemedel
När du väljer ett bindemedel är det vanligtvis baserat på materialet i partiklar och pulver och kraven på användning . Vissa rammningsmaterial får inte lägga till ett bindemedel, eller bara lägga till en liten mängd flöde för att främja sinting . till exempel i surt rammande material, vanligt använda bindemedel inkluderar sodium silikat, ethylsil och silikal} {{} {{2} {2) borates as binders. Alkaline ramming materials often use magnesium chlorides, sulfates, phosphates and their polymers. In addition, some organic substances with high carbon content, such as asphalt and resin, are also used. They can form carbon bonds at high temperatures, thereby enhancing the stability of the material .
Prestanda och tillämpning
◉ Egenskaper
In terms of properties, ramming mass usually does not contain additives such as plasticizers and retarders, and has a low moisture content. When non-water-soluble organic binders are used, the mixture is even free of water. Refractory fibers are also added to some products as reinforcements to further improve the performance of the product.
Compared with the same type of amorphous refractory materials, ramming mass is dry or semi-dry, and its loose characteristics make it non-bonding before forming. Therefore, only through strong ramming can a ramming mass with a dense structure be obtained. The strength in the mixture is usually improved by strong ramming. For those products with temporary binders, the room temperature Styrkan före sintring är relativt låg, och styrkan kommer att ökas avsevärt när den värms upp till sintringstemperaturen . Å andra sidan kan Ramming-massa tillverkad med kemiska bindemedel eller kolinnehållande bindemedel ge en stark bindningseffekt efter lämplig värmebehandling, och därmed få hög styrka .}
◉ Konstruktion och användning
The fire resistance and resistance to erosion by melt of ramming material can be achieved by carefully selecting high-quality refractory raw materials, reasonable proportioning and strong tamping. Compared with castables and plastics, it shows higher stability and corrosion resistance in high temperature environment. However, its service life is greatly affected by the pre-burning before use or the sintering quality when it is used För första gången . Om värmeytan kan sintras till en helhet, utan att spricka och tätt bundna till bottenlagret, kommer dess livslängd att förbättras avsevärt .
Regarding the construction and use of ramming material, it can usually be constructed at room temperature. However, if thermoplastic organic materials are selected as binders, hot mixing and hot ramming construction are required. After molding, different heating methods are required to promote its hardening or sintering according to the hardening characteristics of the mixture. For mixtures containing inorganic chemical binders, the corresponding heat treatment method should be selected according to the hardening characteristics of the binder. For mixtures containing thermoplastic carbon binders, it is necessary to demould after cooling to an appropriate strength and heat quickly before use to promote its coking. In addition, for ramming materials that do not contain binders that harden at room temperature or medium temperature, they are usually sintered with a mold after tamping. For example, siliceous ramming materials can be used to make electric induction furnace linings by adding 1% to 2% boric acid. The mixed materials can be sintered by electric heating after tamping outside the iron core mold. In this way, the lining can be pre-sintered before use, or the sintering process can be completed through a suitable thermal system När det används för första gången .
◉ Roll i smältfältet
Ramming mass plays an important role in the field of smelting. It is often used as a lining material that is in direct contact with molten materials and is widely used in various smelting furnaces. Ramming mass can not only be used to construct the overall lining, but also to manufacture large products. It can even replace refractory bricks to ram specific parts of the metallurgical furnace or the entire furnace. At present, ramming mass is widely used for ramming of part of the lining of the blast furnace, the bottom of the electric furnace, the bottom of the matte smelting reverberatory furnace, and the entire furnace body of the induction furnace. Compared with refractory brick masonry, the rammed furnace body has the significant advantages of no brick Fogar, stark och tät struktur, låg risk för metallläckage och stark korrosionsmotstånd, och dess livslängd är betydligt längre än den för den tegelbyggda ugnskroppen .