CDchem brings you to know and understand the true sodium tripolyphosphate(STPP)

When it comes to sodium tripolyphosphate(STPP), the first thing people think of is washing powder? Yes, the common auxiliaries used in washing powders are STPP, which can be used in combination with metal ions in water to form soluble complexes, thereby eliminating sedimentation and effectively enhancing the washing efficiency of washing powder.

But because of "eutrophication" and the gradual realization of non-phosphating in laundry powder, is STPP useless? In fact, STPP is not only useful in detergent auxiliaries, but also widely used in ceramics, industrial soft water, paper making, drilling mud dispersion, anti-oil stain agent and other industries.

Phosphorus combines with oxygen or phosphorus and other elements to form a variety of phosphorus-containing compounds. Due to the different degree of phosphorus oxidation, it also forms a variety of oxygen-containing phosphate. The oxidation value in the form of phosphorus can be 1/2/3/4/5. In general, phosphorus compounds with oxidation value of 5 are the most common, including phosphorus pentoxide, orthophosphate, peroxy phosphoric acid, polycondensation phosphoric acid, and their corresponding salts. STPP is one of polycondensate.

Phosphate in STPP is composed of three PO4 tetrahedrons, including type I, type II and hexahydrate. It is important to distinguish STPP from sodium trimetaphosphate. Sodium trimetaphosphate is a cyclic compound, which is composed of n PO4 tetrahedrons combined by common oxygen atoms. It exists in the form of type I, II and III) STPP type I and type II. It is mainly determined by the different coordination of sodium ions. That is, all sodium ions in type II are surrounded by oxygen and some sodium ions in type I are surrounded by oxygen atoms. Type I and type II are known as high temperature and low temperature because of their differences in heat release in water.

STPP is mainly made of phosphoric acid and soda or caustic soda. At present, in order to save cost and reduce investment, a large number of phosphate manufacturers use wet-process phosphoric acid and 30% liquid caustic soda as raw materials, and need to cooperate with the process conditions - separation and purification to make the products meet the standards. Because the production process can achieve different conditions, the use of raw materials impurity content difference (for example: from cost savings considerations, some use wet hair phosphoric acid, some use thermal phosphoric acid to focus on quality). So there are obvious reasons for the quality gap of STPP produced by different manufacturers under the same standard in the STPP market.

CDchem has specially developed and produced ceramic grade STPP, aiming at making clay have higher fluidity and uniform dispersion in less water in ceramic production. Using authentic phosphoric acid and soda ash as raw materials, the only internal control index for ceramics in the world has been established. Strict quality control system plays a leading role in the ceramic industry.

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