Grouting forming is a traditional method used for processing ceramic blanks. For the fixed forming equipment and dies, the quality of the blanks
It is mainly determined by mud properties. The slurry meeting the process requirements shall have good fluidity, certain stability and proper
Thixotropy, good filterability, moderate water content, the formed green body has sufficient strength to facilitate demoulding and free of bubbles, etc., and flows
The slurry with good performance shall be used to ensure smooth flow in the pipeline, easy distribution to various parts of the mold, and not easy to settle,
Make all parts of the green body uniform. Adding electrolyte into mud is the main method to improve its fluidity
Is water glass, sodium carbonate, phosphate, sodium humate, sodium tannate, sodium polyacrylate, etc
Glass is the material with the largest consumption, but there are some problems in use, such as large fluctuation of composition, inconvenient measurement, storage and transportation, etc
Sodium metasilicate is a white powder with modulus of 1 [(nSiO2)/n (Na2O), which is made of sodium silicate and caustic soda
Crystal, containing 5 crystal water molecules, melting point 72.2 ℃, easily soluble in water, 1% aqueous solution PH=12.5, slightly alkaline
The reason why it has dilution effect is that it can increase the surface charge density of the micelle in the mud, thus increasing the thickness and ξ electric
The repulsion force between particles is increased; At the same time, the silicate anion contained in sodium metasilicate is the same as Ca2+
Mg 2+harmful ions generate insoluble substances, promote the exchange of N a+, reduce the viscosity of mud, and increase the fluidity
Sodium metasilicate has a strong buffer capacity to the pH value of mud, and the silicate anion contained in it increases the clay particle zone
In addition to the charge density, it is also easy to react with harmful Ca2+and Mg2+ions in the mud to generate insoluble salts and promote the exchange of Na ions
It can generate more Na clay and improve the fluidity of mud: when this mud is added to the mold for forming,
It is easy to react with gypsum, and can quickly produce flocculation and hardening reaction, so as to shorten the green forming time. Sodium metasilicate is generally based on the amount of clay
0.3%~0.5% personnel are added, which is not only suitable for ordinary grouting forming, but also suitable for pressure grouting forming. It is convenient to use and cheap
Good dilution performance.
At the same time, sodium metasilicate is easy to be mixed with other commonly used diluents such as soda ash, phosphate, sodium humate to form a composite dilution solution
The glue has better degumming performance than single degumming agent. At present, sodium metasilicate is the main compound unglued agent sold in the market
It needs ingredients.
In addition, sodium metasilicate has a strong wetting, emulsifying and saponifying effect on fatty substances, and has a strong degreasing performance,
It is widely used to prepare various detergents. In addition, it is also widely used in textile, paper making, oil extraction and other industries
Post time: Oct-24-2022