The production technology of sodium tripolyphosphate

By phosphoric acid by the soda ash and sodium tripolyphosphate are sodium phosphate, then through condensation, the production of phosphoric acid method are two kinds of wet and heat method. Wet to phosphate rock and mineral acid after reaction, after extraction, refining the quick phosphate. Thermal process is in the heart of the electric furnace roasting with silica, phosphate rock and coke content reduction of phosphorus, phosphate rock and oxidation, hydration, quick phosphate.

By the orthophosphate the process of preparing sodium tripolyphosphate is more simple, short process, control is easy to operate. There are two main methods.

Spray drying - converter 2 of polycondensation method. Spray dryer is a cylinder, upper and horizontal burner with the gas nozzle. Temperature is 400 ~ 500 ℃ by the burner gas bubbled into the upper part of the spray drying tower, at the same time with high pressure (4.2 MPa) pump is phosphate solution injection. Water cut of less than 5% of the dry products from the lower part of dryer. Orthophosphate mixture dehydration condensation in the rotary furnace into sodium tripolyphosphate. This method is characterized by product without crushing, spray dryer drying efficiency is high, the drying material is uniform, stratification will not occur. Defect is dry and polycondensation is divided into two sections, direct heating drying dust losses.

A method of dry - dehydration. The slurry injection rotary furnace, furnace in nozzle into heat or burning oil in heating. Ring baffle and heating furnace can be divided into flame. In the heating period, material dehydration condensation and eventually into sodium tripolyphosphate. Cooling tube, become an organic whole repeatedly with rotary furnace by cooling tube in a grinding machine grinding fine granular products, out of a small amount of powder from the furnace recycling in the cyclone separator. This method will be dry, dehydrated, and cooling combined within a unit equipment, has greatly simplified the process, heat utilization rate is higher, and can reduce the infrastructure investment, improve the working conditions.

Pre:The five application areas of ferrous sulfate heptahydrate    Next:The five application areas of ferrous sulfate heptahydrate