A New Technology For Production Of Sodium Tripolyphosphate From WPA

This paper was based on the technology problem that wet-process phosphoric acid (WPA) was used as material to produce sodium tripolyphosphate. All the principles were systematically analyzed during the process. According to these problems,this paper presented some new methods and studied new craft. Firstly,WPA must be purged because purification was a key step,and it contained plenty of extraneous component. If WPA wasn't scavenged,the production was defective. This paper cleaned WPA with a home-made purifying agent. The effects of election of purifying agent and use level of purifying agent were analyzed by experimenting. It was proved that this purifying agent was superior to other purifying agent,and it's manipulation was simpler. Then,the tradition manner of crystallization was evaporating and crystalline,but this paper made the other method . The salt-mixture solution of the disodium hydrogen phosphate and the monometallic odium orthophosphate was put in ethanol. The salt-mixture solution reached saturation and separated out crystals. This new method was easy and energy conservation. Finally,the effects of the neutralizing value,the foam problem of neutralization,polymerization temperature and polymerization time were systematically studied,and analyzed carefully the polymeric reaction mechanism by the change of polymerization temperature and polymerization time. The technological condition of neutralizing reaction and polymeric reaction were optimized and produced sodium tripolyphosphate of uniform size distribution.