Process for continuous production of technical grade mano-ammonium phosphate with wet-process and phosphoric acid

Abstract

The invention relates to a craftwork for producing the industrial-level monoammonium phosphate consecutively with the phosphoric acid by wet process, which adopts the following steps: 1) phosphoric acid and phosphorite pulp are desulfurized to get the desulfurized phosphoric acid; 2) the acid is undertaken the first neutralization action to get a neutralized material pulp clarifying solution; 3) after the second neutralization reaction, the solution is reacted with the desulfrized phosphoric acid to get a secondary neutralized material pulp with the pH value being adjusted; 4) the secondary neutralized material pulp with the pH value being adjusted is primarily filtered to get a primary filtering solution and a primary filtering mass; 5) the primary filtering solution is secondarily concentrated and press filtered to get the secondary filtering solution; 6) the obtained secondary filtering solution is dissolved through the grain refining, is cooled down in vacuum, is crystallized, is centrifugally separated and dried to get the finished product of the industrial-level monoammonium phosphate. The invention has the advantages that the operation during the production process is consecutive; the labor intensity of the worker is reduced; the leakage rate of the ammonia is low and the loss is small; the secondary neutralized raw material solution is clear solution, so that the viscosity is low and the loss of the ammonia is small; the neutralization and the press filtering load is reduced; the crystallization production capacity is large; the heat energy is adequately used, thereby reducing the consumption of the vapor.

Description

technical field [0001] The invention relates to a process for continuous production of industrial-grade monoammonium phosphate by wet-process phosphoric acid. Background technique [0002] Industrial-grade monoammonium phosphate is not only a phosphorus-based flame retardant, but also a high-concentration, high-purity, fully water-soluble compound fertilizer. Its monoammonium phosphate content is greater than 98%, while the purity of ordinary agricultural grade monoammonium phosphate is only 60%. Its main purpose can be used as a fire extinguishing agent for fire extinguishers; it can also be used as an additive for thermal insulation materials to improve the fireproof performance of thermal insulation materials. Because it is a high-concentration, high-purity and fully water-soluble compound fertilizer, it can be used as a foliar irrigation fertilizer for crops. Because halon fire extinguishing agent is destructive to atmospheric ozone, its use has been banned internationa...

AI Technical Summary

Problems solved by technology

[0008] (1) Intermittent operation, low production capacity;

[0009] (2) High labor intensity (large amount of plate and frame filter cake);

[0010] (3) High ammonia consumption (one-time neutralization and high degree of neutralization);

[0011] (4) High energy consumption (single-effect atmospheric pressure concentration);

[0012] (5) The mother liquor cannot be recycled

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