阅读说明：本技术 一种萃余酸制备磷肥系统及其制备工艺 (System and process for preparing phosphate fertilizer from raffinate ) 是由 赵江华 肖升 冉瑞泉 邓喜 白长凡 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种萃余酸制备磷肥系统,包括依次连接的萃余酸贮槽、氨洗涤装置、管反配酸槽、管式反应器、造粒机、干燥装置、筛分破碎装置、流化冷却装置；所述管反配酸槽中添加着色剂；所述管式反应器中添加硫酸和氨气；所述造粒机与氨洗涤装置连接；筛分破碎装置筛分出的不合格料回送入造粒机；流化冷却装置连接旋风除尘装置、尾气洗涤装置。本发明利用萃余酸与氨反应生产磷铵的原理制备磷肥。萃余酸相比农业级磷酸,酸中的含固量、金属杂质量高,为解决氨酸反应过程中的磷反应活性、料浆流动性,采用氨、磷酸、硫酸的三通混合头管反器喷浆造粒。经造粒工序生成磷铵湿颗粒,再经干燥、筛分破碎、冷却、包裹,最终产出合格的磷肥产品。(The invention discloses a system for preparing a phosphate fertilizer by using raffinate acid, which comprises a raffinate acid storage tank, an ammonia washing device, a pipe counter-acid preparation tank, a tubular reactor, a granulator, a drying device, a screening and crushing device and a fluidization cooling device which are sequentially connected; adding a coloring agent into the tube anti-acid preparation tank; adding sulfuric acid and ammonia gas into the tubular reactor; the granulator is connected with an ammonia washing device; returning the unqualified materials screened by the screening and crushing device into a granulator; the fluidization cooling device is connected with the cyclone dust removal device and the tail gas washing device. The present invention prepares phosphate fertilizer by means of the reaction of raffinate acid and ammonia to produce ammonium phosphate. Compared with agricultural phosphoric acid, the raffinate acid has high solid content and metal impurity quality, and adopts a three-way mixing head tube reactor of ammonia, phosphoric acid and sulfuric acid for spray granulation to solve the problems of phosphorus reaction activity and slurry fluidity in the process of amino acid reaction. Wet ammonium phosphate particles are produced through a granulation process, and then the wet ammonium phosphate particles are dried, screened, crushed, cooled and wrapped to finally produce a qualified phosphate fertilizer product.)

1. The utility model provides a raffinate acid preparation phosphorus fertilizer system which characterized in that: comprises a raffinate acid storage tank, an ammonia washing device, a pipe counter-acid preparation tank, a tubular reactor, a granulator, a drying device, a screening and crushing device and a fluidization cooling device which are connected in sequence; adding a coloring agent into the tube anti-acid preparation tank; adding sulfuric acid and ammonia gas into the tubular reactor; the granulator is connected with an ammonia washing device; returning the unqualified materials screened by the screening and crushing device into a granulator; the fluidization cooling device is connected with the cyclone dust removal device and the tail gas washing device.

2. The system for preparing a phosphate fertilizer from raffinate acid as claimed in claim 1, wherein: the fluidization cooling device is connected with the packing device.

3. The system for preparing a phosphate fertilizer from raffinate acid as claimed in claim 2, wherein: the packing device is connected with the bulk material warehouse.

4. The system for preparing a phosphate fertilizer from raffinate acid as claimed in claim 1, wherein: adding part of sulfuric acid into a tubular reactor; ammonia gas is added into the tubular reactor.

5. The system for preparing a phosphate fertilizer from raffinate acid as claimed in claim 1, wherein: also comprises a hot blast stove connected with a drying device.

6. The system for preparing a phosphate fertilizer from raffinate acid as claimed in claim 1, wherein: the tail gas washing device is connected with a chimney.

7. A preparation technology of a system for preparing a phosphate fertilizer by using raffinate acid is characterized in that: the method comprises the following steps:

s1, placing the raffinate acid in a raffinate acid storage tank;

s2, sending the raffinate acid into a tube acid-back-mixing tank through an ammonia washing device;

s3 adding the raffinate acid and sulfuric acid treated by the tube-pass acid-preparing tank into a tubular reactor for reaction;

s4, adding the primary finished product processed by the tubular reactor into a granulator;

s5, drying, screening and crushing the primary finished product processed by the granulator;

s6 returning the unqualified materials after being screened and crushed to a granulator, and feeding the qualified materials to a fluidization cooling device;

and S7, packaging the finished product after the fluidization treatment.

8. The process for preparing a phosphate fertilizer system from raffinate acid as claimed in claim 7, wherein: liquid ammonia is added in the step S3.

Technical Field

The invention relates to the field of phosphate fertilizer preparation, in particular to a system for preparing a phosphate fertilizer from raffinate acid and a preparation process thereof.

Background

Phosphoric acid is a very important intermediate product in the phosphorus chemical industry, and is widely applied to industries such as fertilizer, food, medicine and the like.

Phosphoric acid is currently named according to industrial production methods as thermal phosphoric acid and wet phosphoric acid. The hot-process phosphoric acid is produced by using yellow phosphorus as a raw material, the product purity is high, the impurity content is low, but the production cost is high, the energy consumption is high, the wet-process phosphoric acid is produced by decomposing phosphorite with acid, and compared with the hot-process phosphoric acid, the hot-process phosphoric acid has the advantages of low energy consumption and low production cost, but the requirements on acid impurities of a final product are different according to different purposes of the product, generally, the processes of impurity removal, purification and the like are required to be applied to industry, and the process flow is relatively long. The wet-process phosphoric acid production method is advanced and perfected to purify phosphoric acid mainly by an extraction mode, and industrial-grade and food-grade phosphoric acid can be obtained, so that the wet-process phosphoric acid can also be used for preparing high-added-value phosphorus chemical products, but the obtained byproduct, namely raffinate phosphoric acid, has high impurity content, and the further utilization of the byproduct, namely the raffinate phosphoric acid, is influenced at present.

Compared with fertilizer phosphoric acid, the extraction residual phosphoric acid has lower phosphoric acid content and mass percent concentration of 55-65% (by weight, H) by-product obtained by purifying and preparing industrial grade and food grade phosphoric acid from fertilizer phosphoric acid₃PO₄% of the total fluorine content, the magnesium content is higher, the fluorine mass percent concentration is 0.3-0.6%, the magnesium mass percent concentration is 2-3%, the fluidity is poor, and the content of phosphoric acid is not high.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a system and a process for preparing a phosphate fertilizer by using raffinate acid, which has low impurity content and relatively high purity.

The invention provides a system for preparing a phosphate fertilizer by using raffinate acid, which comprises a raffinate acid storage tank, an ammonia washing device, a pipe counter-acid preparation tank, a tubular reactor, a granulator, a drying device, a screening and crushing device and a fluidization cooling device which are sequentially connected; adding a coloring agent into the tube anti-acid preparation tank; adding sulfuric acid and ammonia gas into the tubular reactor; the granulator is connected with an ammonia washing device; returning the unqualified materials screened by the screening and crushing device into a granulator; the fluidization cooling device is connected with the cyclone dust removal device and the tail gas washing device.

The invention also provides the following optimization scheme:

preferably, the fluidized cooling device is connected with the packing device.

More preferably, the packing device is connected with a bulk material warehouse.

Preferably, part of the raffinate acid and the sulfuric acid are added into a granulation tail gas-liquid separator of a granulator; adding part of raffinate acid into a dry tail gas-liquid separator of a drying device; adding part of sulfuric acid into a tubular reactor; ammonia gas is added into the tubular reactor through an ammonia self-cooler.

Preferably, the drying device also comprises a hot blast stove connected with the drying device.

Preferably, the tail gas washing device is connected with a chimney.

The invention also provides a preparation process of the system for preparing the phosphate fertilizer from the raffinate acid, which comprises the following steps:

s1, placing the raffinate acid in a raffinate acid storage tank;

s2, sending the raffinate acid into a tube acid-back-mixing tank through an ammonia washing device;

s3 adding the raffinate acid and sulfuric acid treated by the tube-pass acid-preparing tank into a tubular reactor for reaction;

s4, adding the primary finished product processed by the tubular reactor into a granulator;

s5, drying, screening and crushing the primary finished product processed by the granulator;

s6 returning the unqualified materials after being screened and crushed to a granulator, and feeding the qualified materials to a fluidization cooling device;

and S7, packaging the finished product after the fluidization treatment.

Preferably, liquid ammonia is added in the step S3.

The invention has the beneficial effects that:

1. the present invention prepares phosphate fertilizer by means of the reaction of raffinate acid and ammonia to produce ammonium phosphate. Compared with agricultural phosphoric acid, the raffinate acid has high solid content and metal impurity quality, and adopts a three-way mixing head tube reactor of ammonia, phosphoric acid and sulfuric acid for spray granulation to solve the problems of phosphorus reaction activity and slurry fluidity in the process of amino acid reaction. Wet ammonium phosphate particles are produced through a granulation process, and then the wet ammonium phosphate particles are dried, screened, crushed, cooled and wrapped to finally produce a qualified phosphate fertilizer product.

2. The content of water insoluble substances in the raffinate acid is low, which affects the preparation of phosphate fertilizer. Usually, the content of water insoluble matters in the raffinate acid is 6-8%, 100% of the raffinate acid can be used, and sulfuric acid is added to adjust nutrients, so that DAP with the nutrient specification of 60% and 57% is produced. If the content of water insoluble substances in the raffinate acid is less than 6%, adding slag acid (slurry at the bottom of the phosphoric acid tank), adding sulfuric acid, and adjusting product nutrients to produce a phosphate fertilizer product; if the content of water insoluble matter in the raffinate is more than 10%, the granulation effect can be influenced by directly using 100% of raffinate.

Drawings

Fig. 1 is a connection diagram of a system for preparing a phosphate fertilizer from raffinate according to a preferred embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the present invention will be further described in detail with reference to the following embodiments.

As shown in fig. 1, the present invention firstly provides a system for preparing a phosphate fertilizer from raffinate, comprising a raffinate storage tank, an ammonia washing device, a pipe counter-acid preparation tank, a tubular reactor, a granulator, a drying device, a screening and crushing device, and a fluidization cooling device, which are connected in sequence; adding a coloring agent into the tube anti-acid preparation tank; adding sulfuric acid and ammonia gas into the tubular reactor; the granulator is connected with an ammonia washing device; returning the unqualified materials screened by the screening and crushing device into a granulator; the fluidization cooling device is connected with the cyclone dust removal device and the tail gas washing device.

The invention also provides the following optimization scheme:

preferably, the fluidized cooling device is connected with the packing device.

More preferably, the packing device is connected with a bulk material warehouse.

Preferably, part of raffinate acid and sulfuric acid are added into a granulation tail gas-liquid separator; adding part of extraction spent acid into a dry tail gas-liquid separator; adding part of sulfuric acid into a tubular reactor; ammonia gas is added into the tubular reactor through an ammonia self-cooler.

Preferably, the drying device also comprises a hot blast stove connected with the drying device.

Preferably, the tail gas washing device is connected with a chimney.

The invention also provides a preparation process of the system for preparing the phosphate fertilizer from the raffinate acid, which comprises the following steps:

s1, placing the raffinate acid in a raffinate acid storage tank;

s2, sending the raffinate acid into a tube acid-back-mixing tank through an ammonia washing device;

s3 adding the raffinate acid and sulfuric acid treated by the tube-pass acid-preparing tank into a tubular reactor for reaction;

s4, adding the primary finished product processed by the tubular reactor into a granulator;

s5, drying, screening and crushing the primary finished product processed by the granulator;

s6 returning the unqualified materials after being screened and crushed to a granulator, and feeding the qualified materials to a fluidization cooling device;

and S7, packaging the finished product after the fluidization treatment.

Preferably, liquid ammonia is added in the step S3.