CN-224212533-U - Ferric phosphate wastewater treatment system

CN224212533UCN 224212533 UCN224212533 UCN 224212533UCN-224212533-U

Abstract

The utility model discloses an iron phosphate wastewater treatment system, which comprises a washing liquid treatment unit, a mother liquid treatment unit and a bipolar membrane electrodialysis unit for separating concentrated mother liquid in the mother liquid treatment unit into ammonia water and sulfuric acid. The bipolar membrane electrodialysis unit replaces an evaporation crystallization system (MVR) to further remove impurities from an ammonium sulfate solution with low quality after a reverse osmosis membrane is concentrated to prepare ammonia water and sulfuric acid, and the prepared ammonia water and sulfuric acid are reused in a front-end wastewater treatment process, so that the raw material input cost of wastewater treatment is reduced, the economic benefit of ammonium sulfate recovery is improved, and the system has the advantages of high wastewater treatment automation degree, time and labor saving, low energy consumption and low wastewater treatment cost of enterprises.

Inventors

SONG HONGLEI
PAN LONG
SU QIANG
SHI YINGFEI
SHI JUNFENG

Assignees

山东锂源科技有限公司
常州锂源新能源科技有限公司

Dates

Publication Date: 20260508
Application Date: 20250507

Claims (9)

1. The ferric phosphate wastewater treatment system comprises a washing liquid treatment unit and a mother liquor treatment unit, and is characterized by further comprising a bipolar membrane electrodialysis unit for separating concentrated mother liquor in the mother liquor treatment unit into ammonia water and sulfuric acid; The washing liquid treatment unit comprises a washing liquid buffer tank, a washing liquid first-stage reaction tank, a washing liquid first-stage filter pressing device, a washing liquid second-stage reaction tank, a washing liquid second-stage filter pressing device, a washing liquid multi-medium filtering device, a washing liquid ultrafiltration device and a washing liquid reverse osmosis device which are connected in sequence; The mother liquor treatment unit comprises a mother liquor buffer tank, a mother liquor primary reaction tank, a mother liquor primary filter press device, a mother liquor secondary reaction tank, a mother liquor secondary filter press device, a mother liquor multi-medium filter device, a mother liquor ultrafiltration device and a mother liquor high-pressure reverse osmosis device which are sequentially connected, wherein the water production output end of the mother liquor high-pressure reverse osmosis device is connected with a lotion reverse osmosis device, the concentrated water output end of the mother liquor high-pressure reverse osmosis device is connected with a bipolar membrane electrodialysis unit, the ammonia water output end of the bipolar membrane electrodialysis unit is connected with the lotion primary reaction tank, the lotion secondary reaction tank, the mother liquor primary reaction tank and the mother liquor secondary reaction tank in a separating mode, the concentrated water output end of the lotion reverse osmosis device is connected with the mother liquor high-pressure reverse osmosis device, and the sulfuric acid output end of the bipolar membrane electrodialysis unit is connected with the lotion multi-medium filter device and the mother liquor multi-medium filter device in a separating mode.
2. The ferric phosphate wastewater treatment system according to claim 1, wherein the primary washing liquid reaction tank, the secondary washing liquid reaction tank, the primary mother liquid reaction tank and the secondary mother liquid reaction tank are respectively provided with an ammonia water metering pump for controlling the reflux amount of ammonia water, and the washing liquid multi-medium filtering device and the mother liquid multi-medium filtering device are respectively provided with a sulfuric acid metering pump for controlling the reflux amount of sulfuric acid.
3. The ferric phosphate wastewater treatment system of claim 2, wherein the primary washing liquid reaction tank, the secondary washing liquid reaction tank, the primary mother liquid reaction tank and the secondary mother liquid reaction tank are respectively provided with a pH meter for monitoring the pH value in the tanks, and the pH meters are respectively interlocked with ammonia water metering pumps in each stage of reaction tanks of the washing liquid treatment unit and the mother liquid treatment unit.
4. The ferric phosphate wastewater treatment system of claim 2, wherein the washing liquid reverse osmosis device and the mother liquor high pressure reverse osmosis device are respectively provided with a pH meter for monitoring the pH value in the device, and the pH meter is respectively interlocked with the sulfuric acid metering pump of the washing liquid treatment unit and the mother liquor treatment unit.
5. The ferric phosphate wastewater treatment system of claim 3, wherein the pH of the primary reaction tank of the washing liquid and the primary reaction tank of the mother liquor is 3.0-4.0.
6. The ferric phosphate wastewater treatment system according to claim 3, wherein the pH values of the washing liquid secondary reaction tank and the mother liquid secondary reaction tank are 8.5-9.0.
7. The ferric phosphate wastewater treatment system according to claim 3, wherein the pH value of the washing liquid reverse osmosis device and the mother liquor high pressure reverse osmosis device is 5.0 to 6.0.
8. The ferric phosphate wastewater treatment system according to claim 1, wherein an activated carbon filter and a chelating resin tower for removing impurities are further arranged between the mother liquor treatment unit and the bipolar membrane electrodialysis unit.
9. The ferric phosphate wastewater treatment system of claim 1, wherein the lotion reverse osmosis device comprises a lotion primary reverse osmosis module, a secondary reverse osmosis module and a tertiary reverse osmosis module, wherein the produced water output end of the mother liquor high-pressure reverse osmosis device is connected with the primary reverse osmosis module, and the concentrated water output end of the primary reverse osmosis module is connected with the mother liquor high-pressure reverse osmosis device.

Description

Ferric phosphate wastewater treatment system Technical Field The utility model relates to a wastewater treatment system, in particular to an iron phosphate wastewater treatment system. Background With the development of new energy industry, market demands of lithium iron phosphate batteries are greatly increased, positive electrode materials of the lithium iron phosphate batteries are mostly produced by an ammonia method, a large amount of wastewater containing heavy metal ions is generated in the process of synthesizing ferric phosphate by the ammonia method, main components in the wastewater contain high-concentration heavy metals such as nitrogen, phosphorus, fluorine, iron, manganese and the like, alkaline earth metals such as magnesium and the like, a small amount of other heavy metals such as nickel, cobalt, zinc and the like, partial fluorine ions are extremely difficult to treat, the environment is greatly polluted due to improper treatment method, and metal resources are lost. At present, the main recovery treatment method comprises the steps of respectively preprocessing mother liquor and washing liquor, then concentrating the mother liquor and the washing liquor through a membrane, preparing pure water by using membrane produced water for recycling, concentrating the membrane concentrated water in an evaporation crystallization system (MVR), and then producing ammonium salt for selling. According to the method, a large amount of ammonia water is required to be added to react with washing liquid or mother liquor to remove phosphate ions and metal ions during pretreatment, sulfuric acid is required to be added to carry out pH value adjustment to ensure the filtering effect when the filtered solution enters a reverse osmosis membrane (RO) for filtering, so that the raw material input cost is increased, and concentrated water is treated in an evaporation crystallization system (MVR), so that the method is time-consuming, labor-consuming, high in energy consumption, low in quality of produced ammonium sulfate and poor in economic benefit. Disclosure of utility model The utility model aims to provide an iron phosphate wastewater treatment system for reducing the input cost of raw materials in the iron phosphate wastewater treatment process. The ferric phosphate wastewater treatment system comprises a washing liquid treatment unit, a mother liquid treatment unit and a bipolar membrane electrodialysis unit, wherein the mother liquid treatment unit is used for separating concentrated mother liquid into ammonia water and sulfuric acid; The washing liquid treatment unit comprises a washing liquid buffer tank, a washing liquid first-stage reaction tank, a washing liquid first-stage filter pressing device, a washing liquid second-stage reaction tank, a washing liquid second-stage filter pressing device, a washing liquid multi-medium filtering device, a washing liquid ultrafiltration device and a washing liquid reverse osmosis device which are connected in sequence; The mother liquor treatment unit comprises a mother liquor buffer tank, a mother liquor primary reaction tank, a mother liquor primary filter press device, a mother liquor secondary reaction tank, a mother liquor secondary filter press device, a mother liquor multi-medium filter device, a mother liquor ultrafiltration device and a mother liquor high-pressure reverse osmosis device which are sequentially connected, wherein the water production output end of the mother liquor high-pressure reverse osmosis device is connected with a lotion reverse osmosis device, the concentrated water output end of the mother liquor high-pressure reverse osmosis device is connected with a bipolar membrane electrodialysis unit, the ammonia water output end of the bipolar membrane electrodialysis unit is connected with the lotion primary reaction tank, the lotion secondary reaction tank, the mother liquor primary reaction tank and the mother liquor secondary reaction tank in a separating mode, the concentrated water output end of the lotion reverse osmosis device is connected with the mother liquor high-pressure reverse osmosis device, and the sulfuric acid output end of the bipolar membrane electrodialysis unit is connected with the lotion multi-medium filter device and the mother liquor multi-medium filter device in a separating mode. Furthermore, the primary washing liquid reaction tank, the secondary washing liquid reaction tank, the primary mother liquid reaction tank and the secondary mother liquid reaction tank are respectively provided with an ammonia water metering pump for controlling the reflux amount of ammonia water, and the washing liquid multi-medium filtering device and the mother liquid multi-medium filtering device are respectively provided with a sulfuric acid metering pump for controlling the reflux amount of sulfuric acid. The bipolar membrane electrodialysis unit separates ammonia water and sulfuric acid from the concentrated mother liquor, the am