Sodium hexametaphosphate (SHMP) is used as a dispersing agent in some clay-processing systems. In ceramic slips, however, performance depends on the clay and accessory minerals, water chemistry, solids loading, pH, mixing procedure and time after preparation. There is no single dosage that can be recommended for every body or plant.
Published studies have examined SHMP in kaolinite and ceramic-grade kaolin suspensions, including its interaction with clay surfaces and its relationship to suspension chemistry and rheology. These studies support evaluating SHMP as a possible dispersant; they do not establish performance for every clay body or for a specific commercial grade.
For a meaningful comparison, keep the clay source, water, solids content, mixing sequence and measurement method consistent. Record the slurry pH and viscosity at a defined temperature and measurement setting, and check whether the result changes after standing. Compare a control with a series of trial additions selected by the plant’s technical team. Treat the outcome as specific to that tested formulation.
Important: The dosage and optimum point must be established by representative testing. The brochure-listed chemical specification below is not a ceramic-slip dosage guide and does not guarantee a viscosity, water reduction, energy saving or finished-tile result.
The brochure identifies the product as sodium hexametaphosphate, formula (NaPO3)6, CAS No. 10124-56-8. It lists the following values under HG/T 2519-2017, Industrial Grade I. They are brochure-listed specification values, not batch test results. Confirm the current grade, applicable standard and lot-specific values against the current TDS and COA before purchase or process qualification.
| Parameter | Brochure-listed value |
|---|---|
| CAS No. | 10124-56-8 |
| Formula | (NaPO3)6 |
| Total phosphates (as P2O5) | 68.0% |
| Inactive phosphates (as P2O5) | ≤ 7.5% |
| Water-insoluble matter | ≤ 0.04% |
| Iron | ≤ 0.03% |
| pH (10 g/L solution) | 5.8–7.3 |
Reference: Tairan product brochure, SHMP specification section. The brochure is not a substitute for a current TDS, SDS or lot-specific COA.
Use representative clay and process water; note the source and preparation method.
Keep solids loading, mixing energy, addition order and elapsed time comparable across samples.
Measure pH and viscosity using the same instrument settings and temperature for each comparison.
Check flow and stability at the actual process stage; a short-term viscosity result alone may not predict storage or production behavior.
Document the tested grade and batch, and obtain the applicable current TDS and COA.
Do not infer a lower fuel bill, reduced water demand, fewer tile defects or a lower rejection rate from a chemical specification alone. Those outcomes require process-specific measurements and a clearly defined baseline.
Andreola, F. et al. “The role of sodium hexametaphosphate in the dissolution process of kaolinite and kaolin.” Journal of the European Ceramic Society, 24(7), 2113–2124 (2004). https://doi.org/10.1016/S0955-2219(03)00366-2
Andreola, F. et al. “Effect of sodium hexametaphosphate and ageing on the rheological behaviour of kaolin dispersions.” Applied Clay Science, 31, 56–64 (2006). The authors studied defined kaolin dispersions under specified temperature, calcium-ion and ageing conditions; those experimental conditions should not be treated as a universal plant recipe. DOI: 10.1016/j.clay.2005.08.004
For product identity and available documents, visit the Tairan SHMP product page. For ceramic processing, share the intended application and request the current product documentation before conducting a plant trial. Final selection should be based on the buyer’s material, water and process conditions.
