low cement castable refractory material

The improvement of the performance of low cement casting material is actually the application of micro powder technology.

There is a gap between the stability of low cement castable and that of laboratory castable.Low cement castable easy to occur problems are: 1, poor construction performance, poor liquidity;2. The hardening speed varies greatly, and there is quick setting or non-setting;3, easy to burst in baking;4. Abscission occurs;5. Low strength and poor wear resistance.These are caused by refractory castable products abnormal damage and other quality problems.

Low cement refractory castable itself in addition to wear resistance, refractory aggregate, is used with good raw materials fine powder and ultrafine powder, cement and admixture, etc., through adjusting the proportion of each component, improve the high temperature performance of castable, thereby improve the strength of refractory castable.

Low cement castable key construction, should pay attention to is: (1) do not arbitrarily increase the water content of refractory castable, (2) mold support set too high, leading to castable water content is too large and vibration compaction;(3) No mold shall be set during lining construction of feeding pipe, and castable material shall be manually daubed;(4) In order to save the mold, the maintenance is less than 48 h to remove the mold, resulting in the casting cracking or internal damage;(5) The material, shape, size, welding quality, quantity, anti-expansion treatment and unreasonable expansion joints of the anchoring parts;Do not follow the operational sequence of dry stirring, wet stirring and feeding, directly mix the dry and wet materials, resulting in the castable is not fully mixed evenly, part of the material is not wetted by water, making the castable has no strength.

There are also key water issues, to use tap water, to avoid the introduction of acid and base impurities, gradually add, in order to make the dispersant in the powder to play a full role.Excessive water addition will directly lead to a significant decline in the strength of refractory castable construction, and in the field construction the water addition tends to exceed the degree of artesification.The pouring body itself is easy to appear when the ambient temperature rises rapidly, the baking burst, resulting in large area of damage.once the temperature of the castable itself is below 5 ℃, the castable will still have no strength even after curing for 24 hours.The construction and maintenance shall be carried out in strict accordance with the 48-hour mold removal mechanism. In dry areas, water and wet maintenance shall be carried out; in cold areas, airtight heating maintenance shall be realized within 48-hour maintenance to ensure the maintenance temperature.

In a word, if the above points can be achieved step by step in accordance with the requirements, it will certainly improve the performance of low cement casting.