CN111285531A

CN111285531A - Method and system for concentrating high-salinity mine water

Info

Publication number: CN111285531A
Application number: CN202010251971.9A
Authority: CN
Inventors: 肖艳; 郭中权; 毛维东; 高杰
Original assignee: China Coal Technology & Engineering Group Hangzhou Environmental Protection Institute Co ltd
Current assignee: China Coal Technology & Engineering Group Hangzhou Environmental Protection Institute Co ltd
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-06-16

Abstract

The invention relates to a water treatment system, in particular to a method and a system for concentrating high-salinity mine water, and belongs to the technical field of coal mine water treatment. The method comprises the steps of firstly pretreating high-salt mine water to remove oil, suspended matters and colloid pollution factors, enabling the effluent to enter a first-stage reverse osmosis system, enabling concentrated water of the first-stage reverse osmosis system to enter a first-stage hardness removal silicon removal system for hardness removal silicon removal treatment, enabling the effluent to enter a second-stage reverse osmosis system, enabling the second-stage reverse osmosis concentrated water to enter a second-stage hardness removal silicon removal system for hardness removal silicon removal treatment, enabling the effluent to enter an ED membrane system, and enabling the first-stage reverse osmosis system and the second-stage reverse osmosis system to be sent to a reuse water pool. According to the method for concentrating the high-salinity well water, the recovery rate of the concentration section can reach 98%, the TDS of the concentrated water can reach 150-200 g/L after concentration, the subsequent evaporation crystallization scale can be reduced by 1/2-3/4 compared with a conventional concentration mode, and the method has the advantages of low investment and low operation cost.

Description

Method and system for concentrating high-salinity mine water

Technical Field

The invention relates to a water treatment system, in particular to a method and a system for concentrating high-salinity mine water, and belongs to the technical field of coal mine water treatment.

Background

With the continuous extension of the coal industry chain, the water demand of related industries is increased sharply, the environmental pollution is increased, the environmental protection requirement of coal mines is higher and higher, the requirement on pollutants in the mine water discharge of the coal mines is not kept in conventional indexes such as oil, suspended matters, organic matters and the like, and salt ions such as soluble total solids, sulfate, chloride, fluoride and the like become new assessment indexes. The harm of high-salinity wastewater to the environment is mainly shown in that the high-salinity wastewater can cause salinization of soil, particularly in northern or northwest arid and semi-arid regions, surface water resources are deficient, and untreated discharge of high-salinity mine well water can damage vegetation growing environment, salinization of soil and pollution of shallow groundwater. Thus, countries have put higher demands on such waste water, and environmentally vulnerable areas require zero discharge to be achieved, separating the salts in the mine water from the water in solid form.

The high-salinity mine water zero-emission start is late, and the current processing technological processes comprise pretreatment, membrane concentration and evaporative crystallization. The pretreatment mainly aims at removing conventional indexes such as suspended matters, oils, organic matters, iron, manganese and the like in water, the membrane concentration is to concentrate the salt in the pretreated high-salt mine water so as to meet the economic and technical requirements of subsequent evaporation crystallization salt separation, and the evaporation crystallization is to perform evaporation salt separation treatment on the high-concentration brine in the membrane concentration stage. The membrane concentration treatment effect directly influences the investment, the operation cost and the system stability of a subsequent treatment system, the existing common concentration mode is high-pressure reverse osmosis, and the defects are that the system operation pressure is high, the requirement on the pressure resistance coefficient is high, the concentration rate is low, the recovery rate can only reach 40% -50% generally, so that the subsequent treatment system has large scale, high investment and high operation cost. The high investment and operation cost restrict the treatment and utilization of high salt mine water to a certain extent. Therefore, the development of an economical and effective concentration mode has important significance on the zero emission treatment and resource utilization of the high-salinity mine water.

Disclosure of Invention

Aiming at the defects of a membrane concentration treatment system in the existing high-salinity well water zero-discharge treatment process, the invention provides a method for concentrating high-salinity well water, the recovery rate of a concentration section of the method can reach 98%, the TDS of concentrated water can reach 150-200 g/L after concentration, the subsequent evaporation crystallization scale can be reduced by 1/2-3/4 compared with the conventional concentration method, and the method has the advantages of low investment and low operation cost.

The invention also provides a high-salinity mine water concentration system for realizing the method.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a method for concentrating high salinity well water, comprising the steps of:

(1) pretreatment and decontamination: the method comprises the following steps of (1) enabling mine water to enter a pretreatment system, and adding PAC and PAM into the pretreatment system to remove oil and suspended matters in the water;

(2) first-stage reverse osmosis concentration: pumping the effluent water obtained in the step (1) into a first-stage reverse osmosis system, concentrating TDS in the water to 10-20 g/L, and recycling the produced water;

(3) first-stage hard removal and silicon removal: sending the concentrated water generated in the step (2) into a primary hardness and silicon removal system to remove most of calcium, magnesium and silicon ions in the water and reduce membrane scaling pollution;

(4) secondary reverse osmosis concentration: delivering the effluent obtained in the step (3) into a secondary reverse osmosis system, further concentrating the primary reverse osmosis concentrated water to 30-50 g/L, and recycling the secondary reverse osmosis produced water;

(5) secondary hard removal and silicon removal: sending the concentrated water generated in the step (4) into a secondary hardness and silicon removal system to further remove calcium, magnesium and silicon ions in the water, and reducing the scaling risk of a subsequent system;

(6) and (3) three-stage ED membrane concentration: sending the effluent water obtained in the step (5) into an ED membrane system, further concentrating the concentrated water of the secondary reverse osmosis system to 150-200 g/L, and returning the fresh water to the secondary reverse osmosis system; and (4) enabling concentrated water of the ED membrane system to enter a subsequent evaporative crystallization system.

The method comprises the steps of firstly pretreating high-salt mine water to remove oil, suspended matters and colloid pollution factors, enabling the effluent to enter a first-stage reverse osmosis system, enabling concentrated water of the first-stage reverse osmosis system to enter a first-stage hardness removal silicon removal system for hardness removal silicon removal treatment, enabling the effluent to enter a second-stage reverse osmosis system, enabling the second-stage reverse osmosis concentrated water to enter a second-stage hardness removal silicon removal system for hardness removal silicon removal treatment, enabling the effluent to enter an ED membrane system, and enabling produced water of the first-stage reverse osmosis system and the second-stage reverse osmosis system to be sent to a reuse water pool.

The high-salinity mine water is mine water generated in the coal mining process, and the salt content is 2000-5000 mg/L.

According to the invention, high-salinity mine water is subjected to pretreatment system to remove oil, suspended matters, colloid, bacteria and other pollutants in the water, then is subjected to primary reverse osmosis concentration to concentrate the mine water TDS to 10-20 g/L, the produced water is recycled, the concentrated water is subjected to primary hardness removal and silicon removal to remove calcium, magnesium hardness, silicon and other scaling components in the water, the effluent is subjected to secondary reverse osmosis concentration to concentrate the mine water TDS to 30-50 g/L, the effluent is subjected to secondary hardness removal and silicon removal, calcium, magnesium and silicon scaling components are removed, and finally the effluent enters an ED membrane system to concentrate the mine water TDS to 150-200 g/L.

Preferably, in the step (1), the pretreatment system comprises a water quantity regulation unit, a coagulation reaction precipitation unit, a filtration unit and an ultrafiltration unit, PAC and PAM are added into the coagulation reaction precipitation unit, the adding amount of PAC is 20-50 mg/L, and the adding amount of PAM is not higher than 0.1 mg/L.

Preferably, the first-stage silicon and hardness removing system in the step (3) comprises two-stage reaction tanks, a clarification tank, a filter tank and an ultrafiltration unit, wherein a magnesium agent and caustic soda or lime milk are added into the first-stage reaction tank, the pH value of the system is adjusted to 10-11, the reaction time is controlled to be 30-60 min, PAM is added into the second-stage reaction tank, the adding amount of PAM is not higher than 0.05mg/L, the reaction time is controlled to be 15-30 min, powdered activated carbon is added into the clarification tank, the adding amount is 30-60 mg/L, and the retention time of the clarification tank is 60-90 min. The filter in the primary silicon and hard removing system adopts a V-shaped filter, and the filtering speed is 8-10 m/h.

Preferably, the effluent Ca of the primary silicon and hardness removing system is controlled²⁺Hardness not greater than 100Mg/L, Mg²⁺The hardness is not more than 100mg/L, and the content of the ionic silicon is not more than 20 mg/L.

Preferably, the turbidity of the effluent of the ultrafiltration unit is controlled to be less than or equal to 1NTU, and the SDI is controlled to be less than or equal to 3.

Preferably, the TDS after the mixing of the produced water in the steps (2) and (4) is less than or equal to 500 mg/L.

Preferably, in the step (5), the second-stage hardness and silicon removal system comprises a tubular membrane unit and an ion exchange unit, a two-stage reaction tank is arranged in front of the tubular membrane unit, lime milk or caustic soda is added into the first-stage reaction tank, PAM is added into the second-stage reaction tank, the reaction time is 30-60 min, the flux of the tubular membrane is not less than 350L/h, and the ion exchange unit adopts strong acid type resin.

A high-salinity mine water concentration system comprises a pretreatment system, a primary reverse osmosis system, a primary hardness removal silicon removal system, a secondary reverse osmosis system, a secondary hardness removal silicon removal system and an ED (oil-in-water) membrane system which are connected in sequence, wherein the systems are connected by a water tank, a water pump and a pipeline;

the pretreatment system comprises a water quantity adjusting unit, a coagulation reaction precipitation unit, a filtering unit and an ultrafiltration unit;

the first-stage silicon and hardness removing system comprises a two-stage reaction tank, a clarification tank, a filter tank and an ultrafiltration unit;

the two-stage hardness removal silicon removal system comprises a tubular membrane unit and an ion exchange unit.

Preferably, the pretreatment system comprises a water quantity regulating tank, a water suction well, a first lifting pump, a pretreatment clarification tank, a pretreatment V-shaped filter tank, a pretreatment water tank, a second lifting pump and a first ultrafiltration device which are sequentially connected, wherein the water quantity regulating tank and the water suction well are of an integrated structure;

the primary hard removal and silicon removal system comprises a first primary reaction tank, a first secondary reaction tank, a clarification tank, a V-shaped filter tank, a primary water tank, a primary lift pump and a second ultrafiltration device which are sequentially connected, wherein the first primary reaction tank, the first secondary reaction tank and the clarification tank are of an integrated structure;

the second-stage hard removing and silicon removing system comprises a second first-stage reaction tank, a second-stage reaction tank, a second-stage lift pump, a tubular microfiltration membrane device, a second-stage water tank, a second-stage lift pump and an ion exchanger which are sequentially connected, wherein the second first-stage reaction tank and the second-stage reaction tank are of an integrated structure.

Preferably, a first water tank and a water pump are arranged between the pretreatment system and the primary reverse osmosis system.

Preferably, the water production pipeline of the first-stage reverse osmosis system is connected with the second water tank, the concentrated water pipeline of the first-stage reverse osmosis system is connected with the third water tank, the third water tank is connected with the first primary reaction tank of the first-stage hard removing silicon system, and a second water pump is further arranged between the third water tank and the first-stage hard removing silicon system.

Preferably, a fourth water tank and a third water pump are sequentially arranged on a pipeline between the second ultrafiltration device of the primary de-hardening and de-silicification system and the secondary reverse osmosis system.

Preferably, a water production pipeline of the secondary reverse osmosis system is connected with the second water tank, a concentrated water pipeline of the secondary reverse osmosis system is connected with the fifth water tank, and a fourth water pump is arranged between the fifth water tank and the second primary reaction tank of the secondary hard silicon removal system; and a sixth water tank and a fifth water pump are sequentially arranged on a pipeline between the second-stage hard removing silicon system and the ED membrane system.

Preferably, a fresh water outlet pipeline of the ED membrane system is connected with the fourth water tank.

Preferably, in the ED membrane system, the system recovery rate is 70-80%, the salt rejection rate is 80-85%, the TDS of concentrated water is 150-200 g/L, and the current density of the ED membrane is 300-400A/m²。

Preferably, the reverse osmosis membrane adopted by the primary reverse osmosis system is a brackish water membrane, the recovery rate is 70-80%, the salt rejection rate is more than or equal to 98.5%, the average flux is not more than 30/h, and the TDS of the concentrated water is 10-20 g/L.

Preferably, the reverse osmosis membrane adopted by the secondary reverse osmosis system is a brackish water membrane or a seawater desalination membrane, the recovery rate is 70-80%, the desalination rate is not less than 98%, the average flux is not more than 25L/h, and the TDS of the concentrated water is 30-50 g/L.

The invention has the beneficial effects that: the high-salinity mine water concentration system adopted by the invention has the advantages that the salinity content in the finally produced concentrated water is high and the water quantity is small through the pretreatment decontamination, the secondary hard desiliconization and the tertiary concentration, the investment and the operation cost of a subsequent high-concentration brine treatment device can be saved, the hard desiliconization is fully considered in the process, the scaling pollution of a membrane treatment system is reduced, the service life of a membrane is prolonged, and the scaling risk of an evaporative crystallization system is reduced. The membrane system produced water is mixed and recycled, and the final produced water TDS is less than or equal to 500mg/L, so that the membrane system produced water can be used for producing and living miscellaneous water.

Drawings

FIG. 1 is a process flow diagram of a high salinity mine water concentration method of the present invention,

figure 2 is a schematic diagram of the structure of a high salinity well water concentration system of the present invention,

description of reference numerals:

a pretreatment system: a water quantity regulating tank 1, a water suction well 2, a first lift pump 3, a pretreatment clarification tank 4, a pretreatment V-shaped filter tank 5, a pretreatment water tank 6, a second lift pump 7 and a first ultrafiltration device 8,

a first water tank 9, a water pump 10, a first-stage reverse osmosis system 11, a third water tank 12,

the first-stage hard removing and silicon removing system comprises: a first primary reaction tank 13, a first secondary reaction tank 14, a clarification tank 15, a V-shaped filter 16, a primary water tank 17, a primary lift pump 18 and a second ultrafiltration device 19,

a fourth water tank 20, a third water pump 21, a two-stage reverse osmosis system 22, a fifth water tank 23 and a fourth water pump 24,

a second-stage hard removal and silicon removal system: a second primary reaction tank 25, a second secondary reaction tank 26, a secondary lift pump 27, a tubular microfiltration membrane device 28, a secondary water tank 29, a second secondary lift pump 30 and an ion exchanger 31,

a sixth water tank 32, a fifth water pump 33 and an ED membrane system 34.

Detailed Description

The technical solution of the present invention will be further specifically described below by way of specific examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

In the present invention, all parts and percentages are by weight, unless otherwise specified, and the equipment and materials used are commercially available or commonly used in the art. The methods in the following examples are conventional in the art unless otherwise specified.

The core of the invention is to provide a high-salinity mine water concentration method, the process flow chart of one specific embodiment of which is shown in figure 1, which is called as a first specific embodiment, and the method comprises the following steps:

In the step (1), the pretreatment system comprises a water quantity regulation unit, a coagulation reaction precipitation unit, a filtration unit and an ultrafiltration unit, PAC and PAM are added into the coagulation reaction precipitation unit, the adding amount of PAC is 20-50 mg/L, and the adding amount of PAM is not higher than 0.1 mg/L.

The filtering unit in the pretreatment system adopts a V-shaped filtering pool.

The primary silicon and hard removing system comprises a two-stage reaction tank, a clarification tank, a filter tank and an ultrafiltration unit, wherein the filter tank in the primary silicon and hard removing system adopts a V-shaped filter tank, and the filtering speed is 8-10 m/h.

And (3) adding a magnesium agent and caustic soda or lime milk into the primary reaction tank of the primary silicon and hardness removing system in the step (3), adjusting the pH value of the system to 10-11, controlling the reaction time to be 30-60 min, adding PAM into the secondary reaction tank, controlling the adding amount of PAM to be not more than 0.05mg/L, controlling the reaction time to be 15-30 min, adding powdered activated carbon into the clarification tank, controlling the adding amount to be 30-60 mg/L, and controlling the retention time of the clarification tank to be 60-90 min.

Control ofEffluent Ca of primary silicon and hard removing system²⁺Hardness not greater than 100Mg/L, Mg²⁺The hardness is not more than 100mg/L, and the content of the ionic silicon is not more than 20 mg/L.

Controlling the turbidity of the effluent of the ultrafiltration unit to be less than or equal to 1NTU and the SDI to be less than or equal to 3.

TDS after the produced water is mixed in the steps (2) and (4) is less than or equal to 500 mg/L.

And (5) the secondary hardness removal and silicon removal system comprises a tubular membrane unit and an ion exchange unit, a two-stage reaction tank is arranged in front of the tubular membrane unit, lime milk or caustic soda is added into the first-stage reaction tank, PAM is added into the second-stage reaction tank, the reaction time is 30-60 min, the flux of the tubular membrane is not less than 350L/h, and the ion exchange unit adopts strong acid type resin.

In the ED membrane system, the recovery rate of the system is 70-80%, the desalination rate is 80-85%, the TD of concentrated water is S150-200 g/L, and the current density of the ED membrane is 300-400A/m²。

The reverse osmosis membrane adopted by the first-stage reverse osmosis system is a brackish water membrane, the recovery rate is 70% -80%, the desalination rate is more than or equal to 98.5%, the average flux is not more than 30/h, and the TDS of the concentrated water is 10-20 g/L.

The reverse osmosis membrane adopted by the secondary reverse osmosis system is a brackish water membrane or a seawater desalination membrane, the recovery rate is 70% -80%, the desalination rate is not less than 98%, the average flux is not more than 25L/h, and the TDS of the concentrated water is 30-50 g/L.

The other core of the invention is to provide a high-salinity mine water concentration system for realizing the method, the structural schematic diagram of which is shown in fig. 2 and is called as a second specific implementation mode, the high-salinity mine water concentration system comprises a pretreatment system, a primary reverse osmosis system 11, a primary hard removal silicon removal system, a secondary reverse osmosis system 22, a secondary hard removal silicon removal system and an ED membrane system 34 which are connected in sequence, and the systems are connected by a water tank, a water pump and a pipeline;

On the basis of the second specific embodiment, the structure of the high-salt mine water concentration system is further improved to obtain a third specific embodiment, and the difference between the third specific embodiment and the third specific embodiment is that the pretreatment system comprises a water quantity regulating tank 1, a water suction well 2, a first lifting pump 3, a pretreatment clarification tank 4, a pretreatment V-shaped filter tank 5, a pretreatment water tank 6, a second lifting pump 7 and a first ultrafiltration device 8 which are sequentially connected, wherein the water quantity regulating tank 1 and the water suction well 2 are of an integrated structure;

a first water tank 9 and a water pump 10 are arranged between the pretreatment system and the first-stage reverse osmosis system 11;

the water production pipeline of the first-stage reverse osmosis system is connected with a second water tank 36, the concentrated water pipeline of the first-stage reverse osmosis system is connected with a third water tank 12, the third water tank 12 is connected with a first-stage reaction tank 13 of the first-stage silicon removal system, and a second water pump is arranged between the third water tank 12 and the first-stage silicon removal system;

the primary hard removal and silicon removal system comprises a first primary reaction tank 13, a first secondary reaction tank 14, a clarification tank 15, a V-shaped filter 16, a primary water tank 17, a primary lift pump 18 and a second ultrafiltration device 19 which are sequentially connected, wherein the first primary reaction tank 13, the first secondary reaction tank 14 and the clarification tank 15 are of an integrated structure;

a fourth water tank 20 and a third water pump 21 are sequentially arranged on a pipeline between the second ultrafiltration device 19 of the primary de-hardening and de-silicification system and the secondary reverse osmosis system;

a water production pipeline of the secondary reverse osmosis system is connected with the second water tank 36, a concentrated water pipeline of the secondary reverse osmosis system is connected with the fifth water tank 23, and a fourth water pump 24 is arranged between the fifth water tank 23 and the second primary reaction tank 25 of the secondary de-hardening and de-silicification system;

the second-stage hardness removal and silicon removal system comprises a second first-stage reaction tank 25, a second-stage reaction tank 26, a second-stage lift pump 27, a tubular microfiltration membrane device 28, a second-stage water tank 29, a second-stage lift pump 30 and an ion exchanger 31 which are connected in sequence, wherein the second first-stage reaction tank 25 and the second-stage reaction tank 26 are of an integrated structure;

a sixth water tank 32 and a fifth water pump 33 are sequentially arranged on a pipeline between the second-stage hard removal silicon removal system and the ED membrane system; and a fresh water outlet pipeline of the ED membrane system is connected with the fourth water tank so as to enable the fresh water to flow back to the second-stage reverse osmosis system.

In the ED membrane system, the recovery rate of the system is 70-80%, the desalination rate is 80-85%, the TDS of concentrated water is 150-200 g/L, and the current density of the adopted ED membrane is 300-400A/m²。

The reverse osmosis membrane adopted by the first-stage reverse osmosis system is a brackish water membrane, the recovery rate is 70-80%, the desalination rate is more than or equal to 98.5%, the average flux is not more than 30/h, and the TDS of the concentrated water is 10-30 g/L.

The reverse osmosis membrane adopted by the secondary reverse osmosis system is a brackish water membrane or a seawater desalination membrane, the recovery rate is 70-80%, the desalination rate is not less than 98%, the average flux is not more than 25L/h, and the TDS of the concentrated water is 30-50 g/L.

Specifically, in this embodiment, the operation process of the method and system for concentrating high-salt mine water is described by taking a high-salt mine water concentration treatment of a certain coal mine in Shandong as an example:

in the pretreatment system, high-salt mine water firstly passes through a water quantity regulating tank 1 to be regulated in water quantity, so that the stable operation of a subsequent system is ensured, then is lifted to a pretreatment clarification tank 4 through a water suction well 2 by a first lifting pump 3, PAC and PAM are added before entering the pretreatment clarification tank, flocculation precipitation reaction occurs in the pretreatment clarification tank, suspended matters in the water are removed, then the water enters a pretreatment V-shaped filter tank 5, the suspended matters and colloidal particles are further removed, the filtered water is temporarily stored in a pretreatment water tank 6, the filtered water is lifted to enter a first ultrafiltration device 8 by a second lifting pump 7, and the produced water is temporarily stored in a first water tank 9.

Water in the first water tank 9 is pumped into the first-stage reverse osmosis system by the water pump 10, the recovery rate of the first-stage reverse osmosis system reaches 75%, the TDS of the concentrated water is 10.6g/L, the adopted reverse osmosis membrane is a brackish water membrane, the produced water is stored in the second water tank 36, and the concentrated water is temporarily stored in the third water tank 12.

The first-stage concentrated water in the third water tank 12 is lifted to a first primary reaction tank 13 of a first-stage silicon removal system through a second water pump, magnesium, caustic soda or lime milk is added into the first primary reaction tank 13, PAM is added into a first secondary reaction tank 14, the pH value is adjusted to about 10.5 in the embodiment, the magnesium adding amount is 110mg/L, the lime milk adding amount is 230mg/L, the water and the medicament are mixed and react, then the water enters a clarification tank 15, powdered activated carbon is added into the clarification tank 15, the adding amount is 45mg/L, the surface load of the clarification tank 15 is 5.5m/h, the effluent after precipitation enters a V-shaped filter tank 16, the filtered water is temporarily stored in a first-stage water tank 17, then the water is lifted to an ultrafiltration reactor 19 through a first-stage lifting pump 18, fine suspended particles and colloid are further removed, and the effluent is temporarily stored in a fourth water tank 20.

The first-stage concentrated water in the fourth water tank 20 is lifted into the second-stage reverse osmosis system 22 by the third water pump 21, the recovery rate of the system reaches 70%, the desalination rate is more than or equal to 98%, the average membrane flux in the embodiment is 20.1L/h, the TDS of the concentrated water reaches 35.3g/L, the TDS of the fresh water is about 320mg/L, the concentrated water is temporarily stored in the fifth water tank 23, and the fresh water is stored in the second water tank 36.

The primary concentrated water is lifted from the fifth water tank 23 to a secondary reaction tank 25 of a secondary de-hardening and de-silicification system by a fourth water pump 24, 62mg/L of magnesium and 106mg/L of caustic soda are added into the secondary reaction tank 25, 0.03mg/L of flocculant PAM0 is added into a second reaction tank 26, the secondary concentrated water is pumped into a tubular microfiltration membrane device 28 by a secondary lifting pump 27, the filtered water is temporarily stored in a secondary water tank 29, the filtered water is lifted to an ion exchanger 31 by a second secondary lifting pump 30, the discharged water is decarburized and then stored in a sixth water tank 32, the discharged water is lifted to an ED membrane system 34 by a fifth water pump 33, the fresh water flows back to a secondary reverse osmosis system, and the concentrated water enters an evaporative crystallization system to perform a.

The treatment scale of the embodiment is 230t/h, the total recovery rate of the concentration section is 98%, the concentration of concentrated water is 186g/L, the total project investment is 6820 ten thousand yuan, the power consumption is 1950 kW.h, the operation cost is 6.75 yuan/ton water, and the TDS of mixed product water is 280 mg/L.

Comparative example

The treatment scale of a high-salt water treatment project in a certain mining area is 200t/h, the concentration mode is two-stage brackish water reverse osmosis and high-pressure Disc Tube Reverse Osmosis (DTRO), the total recovery rate of a concentration section is 92%, the concentration of concentrated water is 60g/L, the total investment of the project is 9500 ten thousand yuan, the power consumption is 2750 kW.h, and the operation cost is 12 yuan/ton water.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The system and method for concentrating high-salinity mine water provided by the invention are described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A method for concentrating high-salinity mine water is characterized by comprising the following steps:

2. The method of high salinity mine water concentration according to claim 1, characterized in that: in the step (1), the pretreatment system comprises a water quantity adjusting unit, a coagulation reaction precipitation unit, a filtering unit and an ultrafiltration unit, PAC and PAM are added into the coagulation reaction precipitation unit, the adding amount of PAC is 20-50 mg/L, and the adding amount of PAM is not higher than 0.1 mg/L.

3. The method of high salinity mine water concentration according to claim 1, characterized in that: and (3) adding a magnesium agent and caustic soda or lime milk into the first-stage reaction tank, adjusting the pH value of the system to 10-11, controlling the reaction time to be 30-60 min, adding PAM into the second-stage reaction tank, wherein the adding amount of the PAM is not higher than 0.05mg/L, the reaction time is controlled to be 15-30 min, adding powdery active carbon into the clarification tank, the adding amount is 30-60 mg/L, and the retention time of the clarification tank is 60-90 min.

4. The method of high salinity mine water concentration according to claim 1, characterized in that: controlling the effluent Ca of the first-level silicon and hard removing system²⁺Hardness not greater than 100Mg/L, Mg²⁺The hardness is not more than 100mg/L, and the content of the ionic silicon is not more than 20 mg/L.

5. A method of high salt mine water concentration according to claim 2 or 3, characterized in that: controlling the turbidity of the effluent of the ultrafiltration unit to be less than or equal to 1NTU and the SDI to be less than or equal to 3.

6. The method of high salinity mine water concentration according to claim 1, characterized in that: TDS after the produced water is mixed in the steps (2) and (4) is less than or equal to 500 mg/L.

7. The method of high salinity mine water concentration according to claim 1, characterized in that: and (5) the secondary hardness removal and silicon removal system comprises a tubular membrane unit and an ion exchange unit, a two-stage reaction tank is arranged in front of the tubular membrane unit, lime milk or caustic soda is added into the first-stage reaction tank, PAM is added into the second-stage reaction tank, the reaction time is 30-60 min, the flux of the tubular membrane is not less than 350L/h, and the ion exchange unit adopts strong acid type resin.

8. The method of high salinity mine water concentration according to claim 1, characterized in that: in the ED membrane system, the recovery rate of the system is 70-80%, the desalination rate is 80-85%, the TDS of concentrated water is 150-200 g/L, and the current density of the ED membrane is 300-400A/m²；

The reverse osmosis membrane adopted by the primary reverse osmosis system is a brackish water membrane, the recovery rate is 70% -80%, the desalination rate is more than or equal to 98.5%, the average flux is not more than 30/h, and the TDS of the concentrated water is 10-20 g/L;

9. A high salinity mine water concentration system for use in the method of claim 1, wherein: the high-salinity mine water concentration system comprises a pretreatment system, a primary reverse osmosis system (11), a primary hard removal silicon removal system, a secondary reverse osmosis system (22), a secondary hard removal silicon removal system and an ED membrane system (34) which are connected in sequence, wherein the systems are connected by a water tank, a water pump and a pipeline;

10. The high salt mine water concentration system of claim 9, wherein:

the pretreatment system comprises a water quantity regulating tank (1), a water suction well (2), a first lifting pump (3), a pretreatment clarification tank (4), a pretreatment V-shaped filter (5), a pretreatment water tank (6), a second lifting pump (7) and a first ultrafiltration device (8) which are sequentially connected, wherein the water quantity regulating tank and the water suction well are of an integrated structure;

the primary hard removal and silicon removal system comprises a first primary reaction tank (13), a first secondary reaction tank (14), a clarification tank (15), a V-shaped filter (16), a primary water tank (17), a primary lift pump (18) and a second ultrafiltration device (19) which are sequentially connected, wherein the first primary reaction tank, the first secondary reaction tank and the clarification tank are of an integrated structure;

the second-stage hard removal and silicon removal system comprises a second first-stage reaction tank (25), a second-stage reaction tank (26), a second-stage lift pump (27), a tubular microfiltration membrane device (28), a second-stage water tank (29), a second-stage lift pump (30) and an ion exchanger (31) which are sequentially connected, wherein the second first-stage reaction tank and the second-stage reaction tank are of an integrated structure.