With the correct operation of the method can reduce the porosity of the refractory bricks

Use the correct method of operation can reduce the rate of porosity of refractory brick. We always meet the refractory brick appear excessive porosity of refractory brick, how can we reduce the occurrence of such a situation?Today we shall all the requirements to introduce how to decrease the porosity of refractory brick rate.

Selection of high density, low water absorption rate of raw materials, through reasonable distribution is the key to prepare low porosity refractory brick. Refractory brick is used in 50% of soft clay and 50% hard clay clinker, ingredients according to a certain size requirements, forming, drying, firing at high temperature 1300~1400 ℃. Refractory brick is mainly kaolinite mineral composition (Al2O3 2SiO2 2H2O) and 6%~7% impurities (potassium, sodium, calcium, titanium, iron oxide). Sintering process is mainly kaolinite continuous dehydration decomposes mullite (3Al2O3 • 2SiO2) crystallization process. Refractory brick in SiO2 and Al2O3 in firing eutectic of low melting of silicate and impurity formation process, surrounded by mullite crystals around. In the burning process of the highest temperature control in 1350 ℃ to 1380 ℃, proper increase of low porosity clay brick firing temperature (1420 ℃), firebrick contraction increased slightly, so that the refractory brick density increases slightly, low porosity can be reduced.

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Technical requirements of castable refractory construction

Castable refractory construction technology requirements:

Anchoring nails welded framework supporting, castable construction, casting, curing, and form removal.

(A) Anchoring nails welded

1 .Anchor nail materials and specifications must be in accordance with the design requirements of the procurement.

2. Distribution and welding quality anchoring nails must be according to the design requirements.

(B) Framework supporting

1. Accurate size, meet the design requirements.
2. Support firm, tight seams ride, missed pulp.
3. Corrosive or strong adhesion castable site isolation layer should be in the template.
4. Reserved for expansion joints of wooden strips should be fixed firmly to prevent vibration during that shift.
5. Before pouring, the template should be brushing release agent.

(C) Castable refractory construction

1. Castable once stirred volume should be limited to less than 30min run.
2. Castable should continuously pouring, pouring the first layer of material before the initial setting, the next layer should be finished pouring castable, if intermittent exceed its initial setting time of construction, construction joints should be required to deal with.
3. When using plug-in vibrator, pouring layer thickness should not exceed 1.25 times the length of the vibrating rod action part, when using flat vibrator, its thickness should not exceed 200mm.

(D) Chaimo

1. Does not load the template should be castable strength to ensure its surface and edges are not damaged due to release the case of form removal.
2. Load a template; you should castable strength of more than 70%, before form removal.

Light and heavy division of alkali resistant castable refractory

Alkali resistant castable refractory in high temperature, resistance, alkali metal oxide erosion refractory called alkali resistant refractory castable. This kind of castable castable combined with ordinary calcium aluminate cement is similar, it is composed of a mixture of alkali resistant refractory aggregate and powder, binding agent and admixture. According to the environment and use condition of different alkali resistant castable refractory material, light and heavy division, and heavy and can be divided into temperature alkali resistant castable refractory and high temperature alkali resistant refractory castable.

1. Light alkali used in refractory castable ceramic aggregates has alkali materials, porous clay clinker, scrap porcelain material, high strength and expanded perlite. Binders with ordinary calcium aluminates cement. Matrix castable refractory powder may be added to high-silica, at an elevated temperature so as to react with the alkali metal oxides, the glaze layer is formed form a dense layer on its surface, to prevent the melt of alkali metal oxide further penetration and corrosion.
2. Heavy Alkali temperature castable high alumina used in aggregate has guessed, clay guessed so on. Use of calcium aluminate cement binder plus silica microparticles, adding silica microparticles help to improve both the strength of castable combination also helps in use, castable lining impermeable layer formed on the surface, which is characterized by intensity and temperature considerable strength after drying, good alkali corrosion performance.