SU841667A1 - Method of dissolving phosphorus containing salts - Google Patents

Description

(54) METHOD FOR SOLVING PHOSPHORUS CONTAINING SALTS

This invention relates to a process for the preparation of solutions of phosphorus-containing salts and may be used in microbiology. There is a method of dissolving phosphorus-containing salts, which includes the dissolution of salt in water at a weight ratio of salt and water 1: (9-12), continuous stirring in a mixer for 2-3 hours, followed by settling of the solution for 3-4 hours, removing it and removing slimeflj. The disadvantage of this method is the low rate of dissolution and incomplete extraction of salt into the solution. The purpose of the invention is to reduce the dissolution time and increase the degree of salt extraction into the solution. The goal has been achieved by the method of dissolving phosphorus-containing salts, including displacement of salt with water in a weight ratio of (1-2.5): 1, mixing the suspension by transporting it through a closed pipeline | TO the volume concentration of salt 28-60Z with the content of solid particles of class 0.04 -0.06 equal to 15-30%. Mixing should be carried out by transporting the suspension through a closed pipeline. The difference between the method is the ratio of salt to water and the mode of mixing. These differences can increase the recovery rate to 96%, i.e. increase it by 16% and reduce the time of dissolution to 2.4 hours, i.e. reducing it by 7%. As shown by experimental studies, hydrodynamically stable suspensions of phosphorus-containing salts are characterized by the following parameters: a volume concentration of 28-60Z with a content of solid particles of 0.04-0.06 mm 15-30%. If either of the two parameters is not observed, the suspensions of the said salts are unstable.

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Example 1. A pilot installation including a 2.5 NF pump, a 350 l mixing tank and a closed pipeline with a diameter of 70 mm and a length of 7.5 m prepare suspensions of phosphorus-containing salts: ammophos, double superphosphate and nitroamophosphate at a weight ratio of salt and water (T: W) equal to O, 7: 1, 1: 1 and 2.5: 1. The degree of readiness of suspensions is determined by the disappearance of granules of the initial (1-4 mm) dimensions, after which the content of particles of the class of 0.04-0.06 mm is determined by means of sieve analysis and the number of cycles of circulation of the initial volume of the suspension required for the preparation of the suspension is recorded.

A sample of the suspension obtained is then placed in a measuring cylinder with a capacity of 500 cm and the density of the suspension and the stabilization time of the interface between the clarified solution and sediment are determined. In parallel, the density and stabilization time are determined for the hydromixtures compiled at the same ratios of the components, but not subjected to transportation through a closed pipeline to obtain hydrodynamically stable suspensions.

The results of the experiment are given in table. one.

The data presented in table. 1 show that the stabilization time of suspensions of ammophos, nitroammophoska and superphosphate prepared by the proposed method is much higher than that of suspensions and slurries of these salts, has not undergone transportation through a closed pipeline according to the proposed method and, as a result, does not contain sufficient quantities of fine particles, subjected to transportation and containing a sufficient number of particles of fine classes, but having a concentration below 28%, i.e. suspensions of phosphorus-containing salts with a volume concentration of 28-60%, with a solids content of the class of 0.04-0.06 mm, equal to 15-30% are stable.

The stability of the suspension has a significant effect on the rate of extraction of phosphorus. The slurry compiled with the claimed weight

carrying components, but not being transported through a closed pipeline until a hydrodynamically stable suspension is obtained, forms dense packed sediment in the tank, covered with a solid crust of crystallized salt, which makes it difficult to maintain the solution preparation process due to the low concentration

phosphorus in them and does not provide a high degree of extraction of phosphorus from salt.

Example 2. The suspension of ammophos is placed in a cylinder made of

plexiglass and equipped with a pressure pipe installed along the axis of the cylinder in the lower part of the bottom and several drain pipes located along the generator of the cylinder on

different levels. The suspension begins to exfoliate to form a layer of clarified solution and sediment. After 6 h, the clarified solution is taken using the drain pipe, the nearest

to the interface, and through the pressure nozzle into the tank, water is supplied to the initial (before the solution is taken) level. The process is repeated many times, until the concentration in the selected solutions is lower than 0.4%. The amount of salt in both cases was 1.2 kg, the volume of water was 1.2 liters.

The results of the experiment are given in table. 2

In tab. 3 presents data on

dissolution of double superphosphate, ammophos and nitroammophoska.

Thus, as follows from the data given in table. 2, povyshekie

the degree of phosphorus recovery is achieved for all phosphorus-containing salts when the phosphorus extraction process is carried out according to the proposed method only when salt and liquid are displaced with their weight

ratio (1-2.5: 1) with further transportation of the resulting hydro-mixture through a closed pipeline to obtain a dynamically stable suspension with a bulk concentration of 28-60%

when the content of solid particles of the class of 0.04-0.06 mm 15-30%.

The economic effect from the introduction of the proposed method at the Ss pulp and paper mill will be 48300r.

Table 1

Claims (2)

Table 2. Claim 1. A method of dissolving phosphorus-containing salts, including mixing the salt with water, mixing the suspension, clarifying and screening the clarified solution, characterized in that, in order to reduce the time of dissolution and increase the degree of salt extraction into the solution, the salt is mixed with water at weight ratio (1-2.5}: 1 and mixing is carried out until the volume concentration 841 710 centration.28-60% when the content of solid particles of the class of 0.04-0.06 mm is 15-30%. 2. Method POP.1, distinguished by the fact that mixing is carried out by transporting the suspension through a closed pipeline. Sources of information taken into account in the examination 1. Andreev A.A. and Bryzgalov LI, Production of fodder yeast, M, Lesna, 1965, p. 119.