Preparation method of sodium tripolyphosphate, sodium hexametaphosphate, or sodium pyrophosphate

The invention belongs to the technical field of phosphor oxysalt, and more specifically relates to a preparation method of sodium tripolyphosphate, sodium hexametaphosphate, or sodium pyrophosphate. According to the preparation method, after material slurry reaction in production process, the neutralization degree is adjusted, sodium chlorate and hydrogen peroxide are added successively, and an obtained mixture is stirred to be uniform, and is subjected to polymerization. The preparation method is friendly to the environment, and is capable of reducing nitrogen oxide exhaust amount; no pollution is caused; product white degree is not influenced; the original production technology is not changed; no extra production equipment is needed; and production cost is reduced. 本发明属于磷的含氧酸盐技术领域，具体涉及种三聚磷酸钠、六偏磷酸钠或焦磷酸钠的制备方法，其在生产过程中料浆反应后，调整中和度，再依次加入氯酸钠和双氧水，搅拌均匀即进入聚合反应工序。本发明的方法环保无污染，显著降低了氮氧化物排放量；不影响产品白度，不改变原生产工艺，不需要增加额外的生产设备；降低了生产成本。