Do you know the role of sodium tripolyphosphate in refractories?
Refractory materials, due to the unique resistance to high temperature, the main workability includes consistency, slump, fluidity, plasticity, adhesion, resilience, coagulability, hardening, etc. According to the chemical properties of the material, it can be divided into acid refractories, neutral refractories, and alkaline refractories. And do you know the role of sodium tripolyphosphate in refractories?
The acid refractories use silicon oxide as the main component, commonly used are silicon bricks and clay bricks. Neutral refractories are mainly composed of alumina, chromium oxide or carbon. Alkaline refractories use magnesium oxide and calcium oxide as the main components, and magnesium bricks are commonly used.
Sodium tripolyphosphate is used as a binder for alkaline refractory materials. Currently, it is mainly used as a binder for magnesium, magnesium calcium and magnesium ingots, forsterite refractory materials and non-fired products.
Experiments show that the sodium polyphosphate used in alkaline refractories contains P1O, controlled at about 69%. No matter it is made into spray material or refractory product, it has fast curing speed and high strength. It can also prevent a lot of shrinkage and cracking caused by dehydration of hydrate when using cement or MgCl2 · MgSO, etc. Sodium phosphate and sodium polyphosphate are very easy Reaction with alkaline refractory material, the melting point of the reaction product is higher, the melting point of Mg (H2PO1) 2 or Mg (PO3) 2 and MgHPO, or Mg2P2O2 produced by reaction with magnesium refractory material is 1165°C and 1382°C.
During the heating process, sodium tripolyphosphate can also undergo polymerization that helps to improve the strength of the material, and the structure of the combination will not be loose due to the phase change, so that its strength from normal temperature to medium temperature is high, even after the liquid phase appears at high temperature, the thermal strength is reduced, but it is much higher than the combination of magnesium sulfate, magnesium chloride and water glass.
At normal temperature, sodium tripolyphosphate also has the function of auxiliary hardening, which is characterized by fast hardening speed and high strength, and can also prevent shrinkage and cracking of the refractory. At the same time, the thermal shock resistance of the refractory can also be improved.
Now the industry is developing rapidly, and the application of refractory materials is more common in various thermal equipment and high-temperature vessels as structural materials and linings that resist the effects of high temperatures. Steel, non-ferrous metals, glass, cement, ceramics, petrochemicals, machinery, boilers, light industry, electricity and other fields of the national economy will be seen.
The properties of the bonding agent must match the properties of the combined refractory castable. For acidic and neutral refractory castables, acidic, neutral and weak alkaline binders can be selected. Basic refractory materials cannot use acidic binders. Only neutral or alkaline binders can be used. If applied under the premise of reduction, organic binders with high residual carbon can also be selected. It can really save energy and get twice the result with half the effort.
The acid refractories use silicon oxide as the main component, commonly used are silicon bricks and clay bricks. Neutral refractories are mainly composed of alumina, chromium oxide or carbon. Alkaline refractories use magnesium oxide and calcium oxide as the main components, and magnesium bricks are commonly used.
Sodium tripolyphosphate is used as a binder for alkaline refractory materials. Currently, it is mainly used as a binder for magnesium, magnesium calcium and magnesium ingots, forsterite refractory materials and non-fired products.
Experiments show that the sodium polyphosphate used in alkaline refractories contains P1O, controlled at about 69%. No matter it is made into spray material or refractory product, it has fast curing speed and high strength. It can also prevent a lot of shrinkage and cracking caused by dehydration of hydrate when using cement or MgCl2 · MgSO, etc. Sodium phosphate and sodium polyphosphate are very easy Reaction with alkaline refractory material, the melting point of the reaction product is higher, the melting point of Mg (H2PO1) 2 or Mg (PO3) 2 and MgHPO, or Mg2P2O2 produced by reaction with magnesium refractory material is 1165°C and 1382°C.
During the heating process, sodium tripolyphosphate can also undergo polymerization that helps to improve the strength of the material, and the structure of the combination will not be loose due to the phase change, so that its strength from normal temperature to medium temperature is high, even after the liquid phase appears at high temperature, the thermal strength is reduced, but it is much higher than the combination of magnesium sulfate, magnesium chloride and water glass.
At normal temperature, sodium tripolyphosphate also has the function of auxiliary hardening, which is characterized by fast hardening speed and high strength, and can also prevent shrinkage and cracking of the refractory. At the same time, the thermal shock resistance of the refractory can also be improved.
Now the industry is developing rapidly, and the application of refractory materials is more common in various thermal equipment and high-temperature vessels as structural materials and linings that resist the effects of high temperatures. Steel, non-ferrous metals, glass, cement, ceramics, petrochemicals, machinery, boilers, light industry, electricity and other fields of the national economy will be seen.
The properties of the bonding agent must match the properties of the combined refractory castable. For acidic and neutral refractory castables, acidic, neutral and weak alkaline binders can be selected. Basic refractory materials cannot use acidic binders. Only neutral or alkaline binders can be used. If applied under the premise of reduction, organic binders with high residual carbon can also be selected. It can really save energy and get twice the result with half the effort.
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