CS272953B1 - Method of powdered triple superphosphate production - Google Patents

Abstract

The invention concerns the method of production of powdered triple superphosphate by decomposition by a mixture of sulphuric acid and trihydrogen phosphate. From the total amount of acid used in the process the added sulphuric acid represents 1.16 to 7.87 % and the share of active hydrogen ions of both acids used in the decomposing reaction is higher than 68.5 and less than 85 % of their stoichiometric requirement.

Description

The invention relates to a process for producing triple powder superphosphate.

In connection with the growing demands of agricultural practice on the quality and content of plant nutrients in industrial fertilizers, the production of solid phosphate fertilizers has moved from simple superphosphate through enriched superphosphate to triple superphosphate. According to existing assumptions, triple superphosphate will maintain its share of approximately 20% among the produced phosphorous fertilizers in the future (UNIDO, Fertilizer Manual, Development and Transfer of Technology, Series No. 13, New York, 1980).

In addition to the classical methods of producing triple superphosphate based on phosphorus decomposition by extraction with trihydrogenphosphoric acid, the possibility of utilizing the known knowledge that the addition of a certain amount of strong mineral acids (sulfuric, nitric, hydrochloric) positively affects the the physico-chemical properties of the product. The addition of sulfuric acid also increases the solidification time of the decomposition slurry. This prolongation of the solidification time of the decomposition sludge in the ventricular method of triple superphosphate production requires adjustments of the mechanical-technological equipment in the technological stage of the fiomogenization of raw materials, respectively. split or multi-stage feed of raw materials (Kopylev et al., Žur. prikl, chim. 7, 1402-1406 (1968), Orechov et al., Agrochimija,

35, 1970; Orechov et al., Chim. prom., 671-673, 1970; Six et al., Chim. prom. 5, 670-672, 1972; US Patents 323395; 1000443; 1224296; Superphosphate, Its History, Chemistry and Manufacture ”, U. S, Department of Agriculture, Dec. 1964th

The utilization of the above-mentioned advantages of phosphorus decomposition by phosphoric and sulfuric acid on the existing machinery technology of the so-called chamber technology enables the production of triple superphosphate, which is the subject of PV 5209-87. Operational tests carried out confirmed the feasibility and validity of this method of production.

It has now been found in the laboratory-operational and operational research that powdered triple superphosphate can be produced, preferably by better utilization of raw materials, in a manner different from the previous one and characterized in that 1.16 to 7.87% of the total amount of acids dosed sulfuric acid and 92.13 to 98.84% dosed extraction trihydrogenphosphoric acid. The proportion of active hydrogen ions of the two acids involved in the decomposition reaction is greater than 68.5% and less than 85% of their stoichiometrically required amount.

The advantage of this method of production is, in particular, lower raw material intensity, the possibility of using an extract of trihydrogenphosphoric acid containing less than 47%

P ^ O- and achieving a higher degree of utilization of phosphorus raw materials than in the climatic process of producing triple superphosphate,

The following examples illustrate but do not limit the scope of the invention.

Example 1

With a Schenk-type weighing scales, 15 t / h phosphorus containing 31.2% P ₂ 0 ₅ milled was continuously fed into the rapid mixer so that the residue on the 0.15 mm sieve was 13.3%. Into a three-row mixer with a speed of approx. 530 rpm. 19.6 t / h of extraction, trihydrogenphosphoric acid of 71.90% and 225 l / h of sulfuric acid at

92.2%. The acids were homogenized in a static mixer before entering the quick mixer. The temperature of the trihydrogenphosphoric acid dosed was 60 ° C. The reaction mixture from the quick mixer fell into a Moritz Standaert maturing chamber, where it solidified and after about 50 min. maturing was mechanically carved and spread on the heap.

The composition of the product when cutting from the maturing chamber was as follows:

content Ρ «θ ₅ in water-soluble form 42.50% content P ₂ 0 ₅ as free HgPO ^ 11.74% content ^Ρ £ θ5 total 45.94% • 9

CS 272 953 Bl

In this way, approximately 120 t of triple superFosFate (as P ₂ 0 ₅ ) was produced in one shift.

Example 2

Consistent way with the example 1 to rovnakoin production equipment has been produced some 120 tonnes (mesh P ₂ 0 _&) of the product being made up nosledovného

P ₂ 0, - - water-soluble - 41,58%

P ₂ O _g - as free ll ₃ P0 ₄ - 10,46% ^P 2 ° 5 ” ^total Ý 46,39% using the following raw materials:

HgPO ^ - 18.6 t / h with a concentration of 72.12%

H ₂ S0 ₄ - 305 1 / h with a concentration of 92.2%

FosForit - 14 t / h with content - 30,49% P ₂ 0g, ³ of ⁵³ % HgO, 48,29% CaO

Example 3

Approximately 105 t (as P ₂ ° 5) of a triple superFosFate of the following composition was produced in a manner consistent with the example but the same production equipment:

P ₂ 0g - water soluble. - 38,75%

P ₂ 0 ₅ - as free HgPO ₄ - 14,42%

P ₂ 0 ₅ - total - 43,26% using the following raw materials:

HgP0 ₄ - 17.7 t / h with a concentration of 66.31% ^H 2 ^SO 4 ³²⁵ Appropriate with a concentration of 94.8% phosphorite - 15 t / h; 31.96% P ₂ 0 ₅ ; 51.82% CaO;

granulometry - 14.61% of the residue on a sieve with 0.15 mm holes.

Claims (1)

OBJECT OF THE INVENTION Process for producing a triple superphosphate powder by decomposing phosphorous acid with three hydrogenphosphoric and sulfuric acids, characterized in that of the total amount of acids 1.16 to 7.87% is fed sulfuric acid and 92.13 to 98.84% is fed trihydrogenphosphoric acid, the proportion of active The hydrogen ions of both acids involved in the decomposition reaction are greater than 68.5% and less than 85% of their stoichiometrically required amount.