CS199155B1 - Process for preparing suspension phosphorous or multicomponent fertilizers - Google Patents

Description

The invention relates to the simplified production of fertilizer containing phosphorus and possibly other fertilizer components.

The prior art processes for the production of phosphite suspensions are generally based on the suspension of finely ground soft carbonate type phosphates in water or fertilizer solutions. Phosphites with a low lattice constant ”and determined by X-ray diffraction are particularly suitable for this purpose. * The generally accepted fineness of grinding of the usable phosphite species is 90% through sieves of 0.063 mm.

By vigorous mixing with water, suspensions containing up to 65 wt. solid phase. A small amount of sodium pyrophosphate was added to reduce viscosity.

Substantial progress in the preparation of phosphorous suspensions has been brought about by the addition of gel-forming substances, such as atapulgite, bentonite or others, which substantially retard sedimentation of the solid particles. However, a considerable disadvantage of the use of these substances is the difficulty and length of their treatment prior to suspension. Phosphite suspensions containing nitrogenous, potassium or magnesium fertilizers in addition to the phosphorus component are also known.

199 155

In all cases described, calcium carbonate content is maintained in phosphorus *

It is known from the literature that it is this component that inhibits the initial uptake of phosphorus by plants on acid soils, i.e. soils for which phosphorous suspensions are predetermined.

The process for the preparation of the fertilizer suspension and of the phosphorous base according to the invention appears to be substantially more advantageous. SUMMARY OF THE INVENTION The present invention is a process for the preparation of slurry phosphate or multi-component fertilizers from finely ground carbonate type phosphates suspended in water or liquid fertilizer, characterized in that calcite and other accompanying substances such as magnesium carbonate are decomposed by addition of acid and / or salt to form a water insoluble calcium compound and carbon dioxide gas, wherein the liquid phase of the suspension is 4 to 7.

The process according to the invention achieves phosphorus activation, which consists mainly in the removal of calcium carbonate, which inhibits the initial uptake of phosphorus by the plants. The fact that the major phosphate mineral, apatite, has no significant chemical attack, is achieved by adding the acids or acidic salts thereof to a final value of 4 to 7.5 by adding the liquid phase of the suspension. The decomposition of the kallel resp. For example, phosphorous acid may be an acid or acid salt whose anion forms a water-insoluble or sparingly soluble precipitate with calcium. They are, for example, phosphoric, sulfuric, sulfuric, oxalic acid and, optionally, its acid salts.

The decomposition precipitate has a stabilizing effect on the phosphite suspension and can fully replace the addition of known stabilizers, such as bentonite. Also, carbon dioxide gas, externally released when the kaleite decomposes, inhibits the sedimentation of the suspended phosphorous particles and thus helps to stabilize as well as the reaction products of the added acids or acid salt with organic and inorganic accompanying substances such as magnesium carbonate contained in the phosphorous feedstock.

In addition to science, scientific solutions of compounds generally used as industrial fertilizers such as ammonium duate, urea, potassium chloride and others may be used to suspend phosphorus. It is particularly advantageous to use industrially produced liquid fertilizers such as MM.

Examples

Example 1

The free acid activated porphosphate suspension from bile emperphosphate was prepared by mixing 540 g of Gafsa phosphite ground to a fineness of 90% through a 0.063 mm sieve and 60% auperephosphate and containing 4.9 wt. of free PgO 4 to 400 g / yr. After reacting, a suspension with a content of 16.7% by weight was obtained. The pH of 1610 g / liter and the pK of the liquid phase measured after 24 hours was 5.8.

Example 2

The suspension and nutrient ratio N: p 2 O 4 = 0.5 was prepared by mixing 100 wt. parts of phosphite of the quality as in Example 1 to a mixture of 30.9 wt. % of a solution of ammonium bisulfite containing 7.6% by weight. N and 40.5 wt. % of DAM solution and 30 wt. Her. The resulting suspension contained 8.4% w / w. N and 16.9% by weight. The PgO4, ^a * ^rn * weight was 1790 g / liter and the pH of the liquid phase after 24 hours was 6.1.

Example 3

Suspensions with the ratio of pure nutrients N t? ₂ ° 5 ^{1 K} 2 ° ⁼ ' ^{1 5 TX} inbox »

420 wt. parts of the phosphate of Example 1 into a mixture of 314 wt. parts by weight of water, 4.0 wt. parts by weight of phosphoric acid 85% »136 wt. parts of urea and 126 wt. parts of potassium salt. After reaction, it contained 6.2 wt. X, 12.5 wt. Ρ _£ ^ 0 and 7.5% by weight. The pH of the liquid phase measured after 24 hours was 6.1.

Claims (1)

Process for preparing soluble phosphate or compound fertilizers from finely ground carbonate type phosphates suspended in water or liquid fertilizer, characterized in that calcite and other accompanying substances, such as magnesium carbonate, are decomposed by the addition of acid and / or acid salts to form a water-insoluble calcium compound. and carbon dioxide gas, wherein the pH of the liquid phase of the suspension is 4 to 7.3.