Continuous dynamic polymerization large-scale production method for high-viscosity non-caking potassium polymetaphosphate

Abstract

The invention discloses a continuous dynamic polymerization large-scale production method for high-viscosity non-caking potassium polymetaphosphate.The method includes: adding a phosphorus containing material and a potassium containing material into a neutralizing tank, stirring for complete reaction, preparing neutralization liquid, and controlling a PH value in 3.0-5.0; transferring the liquid to a smelting furnace with a high-temperature-resistant corrosion-resistance liner directly or after concentration and crystallization or drying and dewatering, performing high-temperature melting at the temperature of 850-1000 DEG C; after materials in the smelting furnace is completely melted, discharging out of the smelting furnace, quickly cooling and solidifying, and grinding to 20 meshes below; transferring to a stainless steel rotary furnace for sintering reaction at the temperature of 450-650 DEG C for 0.5-2.0h, and discharging to obtain the high-viscosity non-caking potassium polymetaphosphate.The high-viscosity non-caking potassium polymetaphosphate can be produced by existing conventional phosphate production equipment, and high efficiency, method simplicity and convenience in implementation are realized.

Description

technical field [0001] The invention relates to a production method of potassium polymetaphosphate, in particular to a continuous dynamic polymerization large-scale production method of high-viscosity non-caking potassium polymetaphosphate. technical background [0002] Potassium polymetaphosphate is also known as Ruhr potassium salt, potassium polyphosphate, potassium metaphosphate, and its molecular formula is: KPO 3 or (KPO 3 )n, the pure product contains 39.87% potassium oxide and 60.13% phosphorus pentoxide, which is a highly polymerized linear polyphosphate, with a small amount of potassium trimetaphosphate and potassium tetrametaphosphate with a ring structure, etc. Existence; Appearance is colorless to white glassy block or sheet, or white fibrous crystal or powder, relative density (25°C) 2.893, melting point 807°C, boiling point 1320°C, slightly soluble in cold water, easily soluble in sodium salt A viscous solution was formed in the solution. Potassium polymeta...

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Problems solved by technology

[0006] Chinese invention patent application publication number CN102897740A "production method and production equipment of potassium polymetaphosphate" and Chinese invention patent application publication number CN102910610A, CN103663402A "preparation method of high viscosity potassium polymetaphosphate" are a kind of sintering method, this method It is only suitable for small-scale intermittent small-batch production. Due to static polymerization, the reaction time is long, the product is easily agglomerated, the efficiency is low, the labor intensity is high, and the inevitable loss of ceramic utensils is very large, and many products are discarded.

[0007] Practice has proved that the potassium polymetaphosphate produced by the melting method has a very small viscosity due to the molecular structure, and has no use value in the food industry; while the sintering method has low temperature softening at about 200 ° C during the reaction process and then partially melts with the temperature rise. The process of high solidification and hardening requires high corrosion resistance of the reaction equipment, and the material cannot be dynamically polymerized. The reaction time is long, and the product is easily agglomerated. Although high-viscosity products can be produced, it is difficult to achieve continuous large-scale production.