阅读说明：本技术 一种饱和卤水净化方法 (Saturated brine purification method ) 是由 刘立平 邱炜 张万 李媛 于 2021-06-25 设计创作，主要内容包括：本发明提供了一种饱和卤水净化方法,包括以下步骤：1)将原料卤水依次置于三级串联储卤池沉降,每个储卤池沉降48～72h；2)将所述初步澄清液与溶气水混合送入气浮净化系统,调整溶气装置出口压力至0.35MPa～0.6MPa；3)将步骤2)得到的清液经过袋式过滤器进行精过滤,过滤压力为0.6～1.0Mpa,布袋过滤精度为1～2μm；4)将过滤得到的清液进行蒸发结晶,气浮处理后含杂质的卤水经过收集返回低一级卤水滩晒池继续滩晒。饱和卤水精制盐效果好,能使悬浮物(ss)降低至20mg/l以下,浊度降低至20NTU以下,盐产品质量高,净化处理成本低,精制过程无废水排放,达到了节能减排的效果,可拓展盐产品的应用领域。(The invention provides a saturated brine purification method, which comprises the following steps: 1) sequentially placing raw material brine in three-stage series halogen storage tanks for sedimentation, wherein each halogen storage tank is sedimentated for 48-72 hours; 2) mixing the preliminary clarified liquid with dissolved air water, sending the mixture into an air flotation purification system, and adjusting the outlet pressure of an air dissolving device to 0.35 MPa-0.6 MPa; 3) fine filtering the clear liquid obtained in the step 2) by using a bag filter, wherein the filtering pressure is 0.6-1.0 Mpa, and the cloth bag filtering precision is 1-2 mu m; 4) and evaporating and crystallizing the clear liquid obtained by filtering, collecting the brine containing impurities after air floatation treatment, returning the brine to the lower-level brine beach drying pool, and continuously beach drying. The saturated brine has good salt refining effect, can reduce suspended matters (ss) to be below 20mg/l and reduce turbidity to be below 20NTU, has high salt product quality and low purification treatment cost, does not discharge waste water in the refining process, achieves the effects of energy conservation and emission reduction, and can expand the application field of salt products.)

1. A saturated brine purification method is characterized by comprising the following steps: the method comprises the following steps:

1) sequentially placing raw material brine in three-stage series halogen storage tanks for sedimentation, wherein each halogen storage tank is sedimentated for 48-72 hours;

2) mixing the preliminary clarified liquid with dissolved air water, sending the mixture into an air flotation purification system, and adjusting the outlet pressure of an air dissolving device to 0.35 MPa-0.6 MPa;

3) fine filtering the clear liquid obtained in the step 2) by a bag filter, wherein the filtering pressure is 0.6-1.0 MPa, and the cloth bag filtering precision is 1-2 mu m;

4) and evaporating and crystallizing the clear liquid obtained by filtering, collecting the brine containing impurities after air floatation treatment, returning the brine to the lower-level brine beach drying pool, and continuously beach drying.

2. The saturated brine purification method of claim 1, wherein: the air-floating purification system is provided with a return water pipeline, and return water is sent to the air dissolving device to produce air dissolving water.

3. The saturated brine purification method according to claim 2, characterized in that: the compressed air is mixed with the reflux water to prepare the 20 percent dissolved air water.

4. The saturated brine purification method according to claim 2, characterized in that: in the air floatation purification process, the circulating water quantity of the air floatation device is 15-25% of the treated water quantity.

5. The saturated brine purification method of claim 1, wherein: the bag filter is a multi-bag quick-opening filter.

Technical Field

The invention relates to the technical field of salt making processes, in particular to a saturated brine purification method.

Background

At present, in the production process of preparing refined salt by adopting seawater saturated brine, the brine refining process is as follows: 1. removing large-particle solids such as mud, sand and other insoluble solid impurities through a settling pond or a settler; 2. filtering again through a sand filter or a multi-media filter. The sand filtering (or multi-medium filter) device has low removal rate of organic matters and colloid in brine and poor decolorization effect, and can not meet the requirement of filtering precision for producing high-quality refined salt. The brine is subjected to seasonal variation, so that organic matters and suspended matter impurities in the purified brine vary with the seasons. When the concentration of the treated brine suspended matters and organic matters is high, the sand filtration device is frequently cleaned reversely, the consumed and purified water quantity is large, and the reduction of the water yield and the improvement of the refining cost are caused. In addition, the saturated brine is low in suspended matter content after sedimentation, soluble organic matters and colloid are difficult to remove, and the requirements on selection of process parameters and technical operation are high. In order to solve the above problems, improve the refining effect of seawater saturated brine, and reduce the purification treatment cost of brine, a brine refining process is urgently needed.

Disclosure of Invention

The invention aims to provide a saturated brine purification method, which has the advantages of good brine purification effect, high salt product quality and low brine purification treatment cost.

Based on the problems, the technical scheme provided by the invention is that the invention provides a saturated brine purification method, which comprises the following steps:

1) sequentially placing raw material brine in three-stage series halogen storage tanks for sedimentation, wherein each halogen storage tank is sedimentated for 48-72 hours;

2) mixing the preliminary clarified liquid with dissolved air water, sending the mixture into an air flotation purification system, and adjusting the outlet pressure of an air dissolving device to 0.35 MPa-0.6 MPa;

3) fine filtering the clear liquid obtained in the step 2) by a bag filter, wherein the filtering pressure is 0.6-1.0 MPa, and the cloth bag filtering precision is 1-2 mu m;

4) and evaporating and crystallizing the clear liquid obtained by filtering, collecting the brine containing impurities after air floatation treatment, returning the brine to the lower-level brine beach drying pool, and continuously beach drying.

Wherein, the air-floating purification system is provided with a return water pipeline which sends return water to the air-dissolving device to produce air-dissolving water.

Further, the compressed air is mixed with the return water to prepare 20% dissolved air water.

In the air floatation purification process, the circulating water amount of the air floatation device is 15-25% of the treated water amount.

Wherein, the bag filter is a multi-bag quick-opening filter.

The air floating device has the working principle that air is dissolved in water with suspended matters under pressurization, then dissolved air bubbles are released by sudden decompression, seawater saturated brine has a coagulation effect in the air floating process due to the fact that the seawater saturated brine contains more organic matters and colloidal substances, and the seawater saturated brine is agglomerated on precipitated particles under the coagulation effect, and can float to the water surface at a certain speed due to the fact that the specific gravity of the seawater saturated brine is greatly lower than that of water. The speed and effect of the method for separating the water-insoluble substances are far better than those of the method for gravity settling, and the separation effect of the water-insoluble substances is more obvious than that of the water-insoluble substances which are close to each other.

The invention has the advantages and beneficial effects that:

the invention provides a method for refining saturated brine by combining clarification, air flotation and cloth bag filtration, which can reduce suspended matters (ss) to be below 20mg/l and reduce turbidity to be below 20NTU, and is used for refining seawater saturated brine, no wastewater is discharged in the refining process, the brine refining effect is improved, the consumption of water, electricity and brine is reduced, the energy-saving and emission-reducing effects are achieved, the production efficiency can be improved for salt-making and salt chemical enterprises, the salt product cost is reduced, the salt product quality can be improved, and the application field of salt products can be expanded; the flocculant and the coagulant do not need to be added, and a good purification effect can be achieved.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings and examples.

Example 1 purification of saturated brine from seawater transported by solarization in Tata, wherein the saturated brine is used130mg/l of water suspension (ss), 100NTU of turbidity and 300m of water inlet flow³And h, further performing the following operation steps:

1) the saturated seawater brine firstly enters a primary brine storage pool to be settled for 48 hours, and suspended matters are

(ss)100mg/l turbidity of 80 NTU; the clear liquid enters a secondary halogen storage pool to be settled for 48 hours, the suspended substance (ss) is 70mg/l, and the turbidity is 65 NTU; the clear liquid enters a third-stage halogen storage pool for sedimentation for 48 hours, the suspended substance (ss) is 60mg/l, and the turbidity is 50 NTU.

2) Sending compressed air with the pressure of 0.45MPa into an air dissolving device, and mixing the compressed air with return water from an air floatation device to prepare air dissolving water with the air concentration of 20 percent; mixing the clear liquid obtained in the step (1) with the dissolved air water at a water inlet of an air floatation device, sending the mixture into the air floatation device, adjusting a releaser at an outlet of the air floatation device to enable the pressure at the outlet of the air floatation device to be 0.4MPa, combining organic matters, suspended matters and micro bubbles in the saturated water to form an impurity foam combination body with the density smaller than that of brine, floating the foam on the upper layer of the brine, returning the foam to the brine beach for recycling after the foam is skimmed by a mud skimming device, and filtering the saturated brine with the suspended matters (ss) of 30mg/l and the turbidity of 32NTU to continue refining.

3. Filtering the saturated brine after air floatation by a quick-open cloth bag filter with the precision of 1 mu m, and clarifying the water suspended matters (ss) by 15mg/l and the turbidity of 18NTU after filtering.

Example 2 purification of saturated brine from seawater by solarization in Tata with suspended solids (ss)130mg/l, turbidity 100NTU, and inflow rate 300m³And h, further performing the following operation steps:

1) the saturated seawater brine firstly enters a primary brine storage pool to be settled for 72 hours, and suspended matters are

(ss)80mg/l turbidity of 60 NTU; the clear liquid enters a secondary halogen storage pool to be settled for 72 hours, the suspended substance (ss) is 50mg/l, and the turbidity is 45 NTU; the clear liquid enters a third-stage halogen storage pool for sedimentation for 48 hours, the suspended substance (ss) is 40mg/l, and the turbidity is 40 NTU.

2) Sending compressed air with the pressure of 0.45MPa into an air dissolving device, and mixing the compressed air with return water from an air floatation device to prepare air dissolving water with the air concentration of 20 percent; mixing the clear liquid obtained in the step (1) with the dissolved air water at a water inlet of an air floatation device, sending the mixture into the air floatation device, adjusting a releaser at an outlet of the air floatation device to enable the pressure at the outlet of the air floatation device to be 0.6MPa, combining organic matters, suspended matters and micro bubbles in the saturated water to form an impurity foam combination body with the density smaller than that of brine, floating the foam on the upper layer of the brine, returning the foam to the brine beach for recycling after the foam is skimmed by a mud skimming device, and filtering the saturated brine with the suspended matters (ss) of 30mg/l and the turbidity of 32NTU to continue refining.

3) Filtering the saturated brine after air floatation through a quick-open cloth bag filter with the precision of 0.8 mu m, and clarifying suspended matters (ss) of water by 12mg/l and the turbidity of 15NTU after filtering.

Although the embodiments of the present invention have been described in detail, the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.