Usually when using phosphate plastic castable, liquid aluminum dihydrogen phosphate (liquid aluminum phosphate) or water glass (sodium silicate solution) can be used to reconcile. These additives can improve the plasticity of the plastic to better suit engineering needs.
Fire-resistant plastic castable is a special type of plastic that is commonly used in construction and repairs in high-temperature environments. It is mainly composed of refractory aggregates, binders and additives, and has the characteristics of high temperature resistance and corrosion resistance. For the tempering of refractory plastics, common practice is to use appropriate liquid or solid additives to achieve this.
In some cases, the following substances may be used for blending:
Liquid additives: Liquid additives usually include liquid sodium silicate (water glass), liquid aluminum dihydrogen phosphate, etc. These liquid additives improve the bonding and plasticity of the plastic castable , making it easier to apply and shape.
Solid additives: Solid additives include various refractory aggregates, refractory fibers, etc. These additives can improve the fire resistance and mechanical properties of plastics and enhance their stability and durability in high temperature environments.
When blending, it is necessary to select appropriate additives according to specific engineering requirements and usage conditions and mix them in a certain ratio to ensure that the refractory plastic has the required performance and engineering quality.
How to extend the storage time of phosphate plastic castable?
The density of phosphoric acid is 1.2~1.g/cm3, and its dosage is 1%~1.5%. The dosage of solid aluminum phosphate and sodium hexametaphosphate is 2% to 6%, and the additives include the inhibitor oxalic acid. Its dosage is 1.0%~1.5%, and calcium lignosulfonate and starch are also used, and its dosage is 0.5% and 0.5%~1.0% respectively. The mix ratio of phosphoric acid refractory plastic is 50%~60% refractory aggregate, %~35% refractory powder, and the mix ratio of phosphate weather-resistant concrete is 60% aggregate, %~35% refractory powder, soft clay %~%, when using, first use 60% phosphoric acid, aggregate powder and soft clay to trap the material.
It is in the form of a hard mud paste and maintains high plasticity for a long time. It contains more plastic clay components and has more moisture than ramming materials. It has good plasticity before hardening and has certain strength after hardening. It has good sintering properties, certain volume stability and other high temperature properties at high temperatures. Can be made into sheets or blocks. Certain binders can also be added during construction. When used, the mixture is compacted or pounded, and after baking, it can form a dense lining and structure.
In the production and construction of refractory plastic castable , the plasticity index is very important, that is, within a certain storage period, the viscoplasticity should be maintained high to facilitate tamping construction. Oxalic acid and citric acid are commonly used as preservatives at home and abroad, but the cost is high. Using molasses as a preservative has a better effect. The mix proportions of the five groups are basically the same. The refractory aggregate and powder are made of bauxite clinker, and Guangxi mud is used as the binding agent. One group is mixed with clay, and the fineness is generally 170 mesh, and the other group is 50 mesh. The binding agent is aluminum sulfate and phosphoric acid or a combination of both. Refractory plastic mixed with molasses can extend the shelf life, which is basically independent of the type and fineness of the clay. For the composite binder of phosphoric acid and aluminum sulfate, without adding molasses, the plasticity index dropped by about 60% after 2 months of storage, and the viscoplasticity was almost lost after 3 months. After adding molasses and storing it for 4 months, the original plasticity index basically remains. For aluminum sulfate binder, after adding molasses and storing it for four months, the plasticity index basically does not change, and drops to about 15% in 8 months. Construction is still possible.
Molasses contains organic acids such as oxalic acid, malic acid and succinic acid, which reduce phosphates and sulfates, thereby extending the shelf life of refractory plastic castable . At the same time, it gives the binder and raw materials a more complete dispersion and wetting time, so that the bonding and viscoplasticity are fully exerted, resulting in the improvement and improvement of high-temperature performance.
