CS254858B1 - Equipment for continuous decomposition of phosphate - Google Patents

Abstract

The proposed device for the continuous decomposition of phosphates with mineral acids consists of series-connected reactors or of series-connected reactors in combination with a group or groups of parallel-connected reactors or of groups of parallel-connected reactors equipped with a stirring device, wherein at least one reactor or group of reactors has a larger reaction volume and/or cross-sectional area at the level of the decomposed reaction mixture or above it than any subsequent reactor or group of reactors. The reactor assembly can be provided with at least one phosphate and acid mixer and/or a spraying and/or a mechanical device for breaking up foam and/or an installation and/or a stirring device limiting the vertical mixing of the reaction mixture. The proposed device for the continuous decomposition of phosphates with mineral acids is suitable for use in the production of industrial fertilizers.

Description

The invention relates to an apparatus for the continuous decomposition of a phosphate or a mixture of phosphates by a mineral acid or a mixture of mineral acids.

The equipment used for continuous decomposition of phosphates by mineral acids is an assembly of equally sized stirred reactors, possibly supplemented by a liquid-solid-phase mixer. Typically, the decomposition device is composed of three to five reactors. In the decomposition of a phosphate feedstock, in particular of sedimentary origin, which contains organic substances and carbonates, a considerable amount of foam is produced, especially in the first reactor. The foaming intensity decreases as the rate of decomposition decreases, i.e. directly depends on the decomposition acid concentration in the reactors. The required low acid concentration is achieved by using a device not built from large volume reactors to decompose the required amount of phosphate feedstock. Such a reactor assembly is then advantageous in terms of reducing foaming problems, but the total volume of reactors used is inefficiently utilized.

As is evident, the drawback of the devices used to continuously decompose, in particular, sedimentary phosphate species by mineral acids, is primarily that an excessively large decomposition device is used to reduce foaming problems.

This disadvantage is solved by a device for the continuous decomposition of a phosphate or phosphate mixture by a mineral acid or a mineral acid mixture, consisting of a reactor assembly equipped with a stirrer, consisting of series connected reactors or series connected reactors in combination with a group or groups of parallel connected Reactors or groups of parallel-connected reactors, wherein the individual branches consist of at least one reactor or more in series and / or parallel-connected reactors, the at least one reactor and / or group of reactors having a larger reaction volume and / or cross-sectional area at the level of or above it, before any subsequent reactor or group of reactors.

Preferably, the device is provided with at least one spraying device for breaking the foam.

September / f. Advantageously, at least one mechanical foam breaking device is provided.

The device is preferably provided with at least one acid mixer or a mixture of acids and phosphate or a mixture of phosphates.

The apparatus may be provided with a built-in and / or mixing device limiting the vertical agitation of the reaction mixture.

The basic effect of the apparatus for the continuous decomposition of a phosphate or phosphate mixture with a mineral acid or a mixture of these acids according to the invention is that the decomposition rate is slowed down especially in the first reactor by lowering the decomposition acid concentration therein. the degradation of some undesirable accompanying components is reduced, while the utilization of the reaction volume of the decomposition apparatus is improved.

The proposed apparatus for the continuous decomposition of phosphates by mineral acids may consist of an assembly of reactors of different reaction volume and / or different cross-sectional areas at or above the level of the decomposed reaction mixture provided with a stirring device. The type and design of the reactor can be chosen arbitrarily, for example, U-type or pot-type reactors, or different types of reactors can be used in the assembly. It is necessary that the decomposition device be composed of series connected reactors in combination with a group or groups of parallel connected reactors or groups of parallel connected reactors, wherein the individual branches consist of at least one reactor or more series and / or parallel connected reactors, at least one reactor or the group of reactors has a larger reaction volume and / or a cross-sectional area at or above the level of the decomposed reaction mixture than any of the reactors; Reactor or group of reactors.

From a manufacturing and operational point of view, it is preferable that the assembly comprises, for example, two reactor sizes whose reaction volumes and / or cross-sectional areas at or above the level of the decomposed reaction mixture can be in a ratio of 10: 1. The reactor assembly may also be provided with at least one phosphate-acid mixer and / or a scrubbing and / or mechanical foam breaker and / or a built-in and / or agitator to limit vertical mixing of the reaction mixture.

An example of a device for the continuous decomposition of phosphates by mineral acids according to the invention is schematically illustrated in the figure which represents one possible solution of an industrial decomposer assembly. The apparatus consists of one larger reactor 1 equipped with a stirrer and four smaller reactors 2, 3, 4, 5, also equipped with a stirrer. The group of smaller reactors 2, 3 connected in parallel is connected in series with respect to the previous first larger reactor 1, and the subsequent series connected smaller reactors 4, 5. In front of the reactor

1, a mixer 6 is provided, into which a decomposition acid supply 7 and a phosphate feed 13 enter. The individual reactors 1, 2, 3, 4, 5 are connected to each other in a cascade by means of overflows.

The device according to the invention operates as follows. The phosphate feedstock and the decomposition acid are continuously fed into the mixer 6 in an appropriate ratio, from where they further enter the first larger reactor and the partially decomposed reaction mixture enters a group of smaller reactors 2, 3 in parallel ^with which it is fed to serially connected smaller reactors 4. 5. 1 reactor which is leaving the reactor? ·; n ^;; slush.

N-C C HAZARDS TO CONTINUOUS DECOMPOSITION OF PHOSPHATES BY MIRRIC ACIDS: 'PROBABLE FOR' MANUFACTURING.

Claims (5)

P k E L ‘M A T Y Y N E Z An apparatus for continuously decomposing a phosphate or phosphate mixture by a mineral acid or mineral acid mixture, comprising an assembly of reactors provided with a mixing device, characterized in that it consists of series connected reactors (1, 4, 5) or series connected reactors (1, 4, 5). 4, 5) in combination with a group or groups of parallel-connected reactors (2, 3) or from groups of parallel-connected reactors, wherein the individual branches consist of at least one reactor or more in series and / or parallel connected reactors, has a larger reaction volume and / or cross-sectional area at or above the level of the decomposed reaction mixture than any subsequent reactor or group of reactors. 2. Apparatus according to claim 1, characterized in that it is provided with at least one spraying device for breaking the foam. Device according to Claims 1 and 2, characterized in that it is provided with at least one mechanical foam breaking device. Device according to one of Claims 1 to 3, characterized in that it is provided with at least one mixer (6) into which the acid inlet (7) or mixture of acids and the inlet (8) of phosphate or mixture of phosphates flows. Apparatus according to any one of Claims 1 to 4, characterized in that at least one reactor is provided with a built-in and / or a mixing device limiting the vertical agitation of the reaction mixture.