CN1116181A

CN1116181A - Ammonium salt producing method coproduced from making pure phosphoric acid method

Info

Publication number: CN1116181A
Application number: CN 94101973
Authority: CN
Inventors: 王昌志
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-08
Filing date: 1994-03-08
Publication date: 1996-02-07

Abstract

Said method uses ammonium bihydrogen phosphate, diammonium hydrogen phosphate or triammonium phosphate as main raw material and makes them react respectively with rarious kinds of acids to produce pure phosphate and coproducts of ammonium salt. The productivity of said method reaches more than 95%. Said invention has advantages of reliable technology, stable quality, no environmental pollution, low cost, and high economic results.

Description

Method for preparing pure phosphoric acid and co-producing ammonium salt

The invention relates to a method for preparing pure phosphoric acid and coproducing ammonium salt by using ammonium dihydrogen phosphate, diammonium hydrogen phosphate or triammonium phosphate as a main raw material and reacting with different acids respectively.

The method for preparing pure phosphoric acid and coproducing ammonium salt products by reacting monoammonium phosphate or diammonium phosphate or triammonium phosphate with acid does not exist in China at present.

At present, two methods are available for producing pure phosphoric acid in China: 1. thermal phosphoric acid, which is prepared by oxidizing phosphorus with a large amount of air to generate acid anhydride P₂O₅Then absorbing P with water₂O₅To form phosphoric acid.

2. The wet-process phosphoric acid is produced by using phosphorite and sulfuric acid as raw materials, and then impurities in the wet-process phosphoric acid are removed by a chemical method, an organic solvent extraction method, an ion exchange method and the like.

The yellow phosphorus used as the raw material of the thermal phosphoric acid is a chemical hazardous article which is spontaneous combustion, inflammable and highly toxic, and the production is unsafe. Yellow phosphorus is expensive, the production cost is high, the purification process of wet-process phosphoric acid is complex, and the production cost is high. The one-time investment is also large.

The purpose of the invention is: the defects of the prior method are avoided, and a method for preparing pure phosphoric acid and coproducing ammonium salt products by using chemical fertilizer ammonium orthophosphate is created, so that a novel process with safe production, reliable process, no pollution and stable product quality is provided.

The content of the invention is as follows: the fertilizer ammonium dihydrogen phosphate or diammonium hydrogen phosphate or triammonium phosphate and different acids are used as raw materials to prepare phosphoric acid and coproduce ammonium calendula products, and the reaction is as follows by taking ammonium dihydrogen phosphate and hydrochloric acid as raw materials:

the invention comprises the following steps: 1. the phosphoric acid and the crystalline ammonium salt are prepared by respectively reacting crystalline ammonium orthophosphate with acid containing a certain amount of water. 2. The ammonium salt produced by washing the acetone by organic dissolution. 3. The concentrated phosphoric acid and ammonium salt mixture was diluted with an organic solvent (acetone).

The method is characterized in that: (1, preparing phosphoric acid by using monoammonium phosphate or diammonium phosphate or triammonium phosphate as a main raw material and different acids as auxiliary materials to respectively co-produce different ammonium salt products).

1. The crystallized ammonium orthophosphate is respectively reacted with different acids with specified concentration to directly prepare phosphoric acid and respectively co-produce different ammonium salt crystallized products, and the phosphoric acid is obtained by centrifugal separation. 2. 20 percent hydrochloric acid and ammonium orthophosphate salt are adopted for crystallization reaction, and no hydrogen chloride gas overflows.

Compared with the prior art, the invention has the following characteristics:

1. the process is reliable, no hydrogen chloride overflows during the reaction, and no environmental pollution is caused. 2. Low production cost, high energy consumption, easily available and storable main material, and high safety. 3. The product quality is stable, and the yield is more than 95%. 4. The diluent and the detergent are recycled. The loss is small.

The attached drawing is the process flow of the invention. (taking the reaction of ammonium dihydrogen phosphate and hydrochloric acid to prepare phosphoric acid and co-produce ammonium hydride as an example).

The invention is further described below with reference to the accompanying drawings.

1. Adding 1.5 kg of ammonium dihydrogen phosphate into the reaction formula (1), adding 182.5 kg of 20% hydrochloric acid, stirring for 20 minutes, heating to 90 ℃, cooling for crystallization, and conveying the cooled and crystallized liquid-solid mixture into a centrifuge (2) to separate out dilute phosphoric acid and ammonium chloride crystals. The diluted phosphoric acid is put into an evaporator (6) to be heated and evaporated to remove water, then the diluted phosphoric acid is cooled to 45 ℃ and put into a diluter (7), 50 kilograms of acetone is added into the diluter (7), the mixture is uniformly stirred and put into a filter-pressing separator (8) to separate acetone phosphoric acid solution.

The phosphoric acid enters a distiller (9), and the distilled phosphoric acid is put into a phosphoric acid storage tank (11).

Secondly, putting the ammonium chloride crystals separated by the centrifugal machine (2) into a washing filter-pressing barrel (3), adding acetone for soaking, then carrying out filter-pressing separation, and sending the separated ammonium chloride crystals into a dryer (4); the ammonium chloride separated in the filter press (8) is fed into the filter press (4) and the dried ammonium chloride is fed into the packing machine (5).

Thirdly, the acetone vapor distilled by the distiller (9) is cooled by a cooler (10) to form acetone liquid which is put into an acetone storage tank 12.

Claims

1. A method for co-producing ammonium salt from purified phosphoric acid, comprising:

(1) ammonium dihydrogen phosphate or diammonium hydrogen phosphate or triammonium phosphate is used as a raw material and reacts with different acids respectively to prepare pure phosphoric acid and produce different ammonium salts.

(2) Washing the co-produced ammonium salt with an organic solvent (e.g. acetone)

(3) Diluting the solid mixture of concentrated phosphoric acid and ammonium salt with organic solvent (such as acetone).

2. The method of claim 1, wherein:

(1) the crystallized normal acid salt reacts with different acids with specified concentration respectively to directly prepare phosphoric acid and co-produce different ammonium salt crystallized products respectively.

(2) And (3) crystallizing and reacting with ammonium orthophosphate salt by using hydrochloric acid with the concentration of less than 22%.

3. The method of claim 1, wherein:

(1) no hydrogen chloride is generated during the reaction, and no environmental pollution is caused.

(2) Easy separation of phosphoric acid and ammonium salt, high yield