阅读说明：本技术 一种磷石膏回用废水结垢资源回收利用的方法 (Method for recycling scaling resources of phosphogypsum recycling wastewater ) 是由 张岳安 邓金元 刘争辉 戴锐 于 2021-09-09 设计创作，主要内容包括：本发明公开了一种磷石膏回用废水结垢资源回收利用的方法,包括以下步骤：S1、将磷石膏回用废水结垢中加入强碱溶液,溶解过滤后得到母液以及氢氧化镁固体、氢氧化钙固体；S2、对母液进行纳滤分离后得到一价离子溶液、二价离子溶液；S3、一价离子溶液进行蒸发浓缩后过滤,得到氟化钠和碱性混合溶液；S4、二价离子溶液中加入硫酸调节pH值至1～2,通过离心分离操作后得到硅酸和第一硫酸钠溶液；S5、第一硫酸钠溶液经过膜浓缩操作后得到饱和硫酸钠溶液；S6、将饱和硫酸钠溶液在-10℃～-5℃的温度下冷藏2h,得到芒硝和第二硫酸钠溶液,第二硫酸钠溶液与第一硫酸钠溶液混合后再次进行步骤S5的操作。(The invention discloses a method for recycling scaling resources of phosphogypsum recycling wastewater, which comprises the following steps: s1, adding a strong alkali solution into the scale formation of the phosphogypsum reuse wastewater, and dissolving and filtering to obtain a mother solution, magnesium hydroxide solid and calcium hydroxide solid; s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution; s3, evaporating and concentrating the monovalent ion solution, and filtering to obtain a sodium fluoride and alkaline mixed solution; s4, adding sulfuric acid into the divalent ion solution to adjust the pH value to 1-2, and performing centrifugal separation to obtain silicic acid and a first sodium sulfate solution; s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution; s6, refrigerating the saturated sodium sulfate solution at the temperature of-10 to-5 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, and mixing the second sodium sulfate solution with the first sodium sulfate solution and then performing the operation of the step S5 again.)

1. A method for recycling scaling resources of phosphogypsum recycling wastewater is characterized by comprising the following steps: the method comprises the following steps:

s1, adding a strong base solution into the scale formation of the phosphogypsum reuse wastewater, stirring and dissolving for 30min at the temperature of 30-80 ℃, and filtering to obtain a mother solution, magnesium hydroxide solids and calcium hydroxide solids;

s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution;

s3, carrying out evaporation concentration on the monovalent ion solution, and then filtering to obtain a sodium fluoride and alkaline mixed solution, wherein the alkaline mixed solution is used for dissolving the scaling of the phosphogypsum recycling wastewater in the step S1;

s4, adding sulfuric acid into the divalent ion solution to adjust the pH value to 1-2, and performing centrifugal separation to obtain silicic acid and a first sodium sulfate solution;

s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution;

s6, refrigerating the saturated sodium sulfate solution at the temperature of-10 to-5 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, and mixing the second sodium sulfate solution with the first sodium sulfate solution and then performing the operation of the step S5 again.

2. The method for recycling scaling resources of phosphogypsum recycling wastewater according to claim 1, which is characterized by comprising the following steps: the strong alkali solution in the step S1 is a sodium hydroxide solution, and the concentration of the strong alkali solution is 10-40%; the mass ratio of the strong alkaline solution to the scale of the phosphogypsum recycled wastewater is 1: 0.5.

3. The method for recycling the scaling resources of the phosphogypsum recycling wastewater according to claim 2, which is characterized by comprising the following steps: the concentration of the sulfuric acid in the step S4 is 5-15%.

Technical Field

The invention relates to the field of phosphogypsum production, in particular to a method for recycling scaling resources of phosphogypsum recycling wastewater.

Background

The wet preparation of phosphoric acid refers to the dissolution of phosphate ore with acids such as sulfuric acid, hydrochloric acid, nitric acid, etc. And discharging the dissolved waste slag and wastewater to a tailing pond for stacking and sedimentation, and recycling the stacked and sedimentated wastewater. In the process of recycling the wastewater, the SiF in the wastewater is caused to be stored₆ ^2-、K⁺、Na⁺The continuous enrichment of plasma, and the waste water temperature of discharging to the tailing storehouse from the workshop is higher, finally leads to in the waste water fluosilicate supersaturation, and the pipeline temperature reduces during the retrieval and utilization, and rivers disturbance is violent, causes the fluosilicate in the waste water to separate out the scale deposit in pipeline, causes pipeline to block, influences enterprise's production. The phosphogypsum recycling wastewater of certain phosphorus chemical enterprises in Hubei reaches 20000m³And (2) each ton of wastewater generates 20-30 kg of scale, and the potassium fluosilicate accounts for more than 90% of the scale on a dry basis and has more mineral resources through test analysis.

At present, scale produced by phosphogypsum recycling wastewater at home and abroad is deposited together with phosphogypsum tailing waste residues in a phosphogypsum tailing pond, so that the resource waste is greatly caused, and therefore, a technology which is easy to operate and low in cost is urgently needed to be found for recycling mineral resources in the scale of the phosphogypsum tailing recycling wastewater.

Disclosure of Invention

The invention aims to solve the problems and provides a method for recycling the scaling resources of the phosphogypsum recycling wastewater, which is simple to operate and high in utilization rate.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method for recycling scaling resources of phosphogypsum recycling wastewater comprises the following steps:

s1, adding a strong base solution into the scale formation of the phosphogypsum reuse wastewater, stirring and dissolving for 30min at the temperature of 30-80 ℃, and filtering to obtain a mother solution, magnesium hydroxide solids and calcium hydroxide solids;

s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution;

s3, carrying out evaporation concentration on the monovalent ion solution, and then filtering to obtain a sodium fluoride and alkaline mixed solution, wherein the alkaline mixed solution is used for dissolving the scaling of the phosphogypsum recycling wastewater in the step S1;

s4, adding sulfuric acid into the divalent ion solution to adjust the pH value to 1-2, and performing centrifugal separation to obtain silicic acid and a first sodium sulfate solution;

s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution;

s6, refrigerating the saturated sodium sulfate solution at the temperature of-10 to-5 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, and mixing the second sodium sulfate solution with the first sodium sulfate solution and then performing the operation of the step S5 again.

Further, the strong alkali solution in the step S1 is a sodium hydroxide solution, and the concentration of the strong alkali solution is 10% to 40%; the mass ratio of the strong alkaline solution to the scale of the phosphogypsum recycled wastewater is 1: 0.5.

Further, the concentration of the sulfuric acid in the step S4 is 5% to 15%.

Compared with the prior art, the invention has the advantages and positive effects that:

dissolving scale of the phosphogypsum reuse wastewater by using a strong base solution to obtain magnesium hydroxide solid and calcium hydroxide solid, separating a mother solution into a monovalent ion solution and a divalent ion solution to obtain sodium fluoride and an alkaline mixed solution from the monovalent ion solution, and obtaining silicic acid and mirabilite from the divalent ion solution; the recovery operation of various mineral resources in the scale formation of the phosphogypsum recycling wastewater is realized, and the waste of the mineral resources is avoided; and the whole recovery process is simple to operate, convenient and quick, and low in cost, so that the difficulty in recovering minerals in the scale of the phosphogypsum recycling wastewater is reduced, and the recovery utilization rate of mineral resources is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a block diagram of the framework of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived from the embodiments of the present invention by a person skilled in the art without any creative effort, should be included in the protection scope of the present invention.

Embodiment 1, as shown in fig. 1, this embodiment discloses a method for recycling scaling resources from phosphogypsum-recycling wastewater, comprising the following steps:

s1, adding a 10% sodium hydroxide solution into the scale formation of the phosphogypsum recycling wastewater, wherein the mass ratio of the sodium hydroxide solution to the scale formation of the phosphogypsum recycling wastewater is 1: 0.5; stirring and dissolving at 30 deg.C for 30min, and filtering to obtain mother liquor, magnesium hydroxide solid, and calcium hydroxide solid; the main components of the mother liquor are sodium ions, hydroxide ions, silicate ions, potassium ions and the like;

s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution; the main components of the monovalent ion solution are sodium ions, potassium ions, fluorine ions and hydroxide ions; the main components of the divalent ion solution are sulfate ions, sodium ions, phosphate ions and the like;

s3, evaporating and concentrating the monovalent ion solution, and filtering to obtain a sodium fluoride and alkaline mixed solution, wherein the alkaline mixed solution is a mixed solution of potassium hydroxide and sodium hydroxide; the alkaline mixed solution can be used for dissolving the scaling of the phosphogypsum recycling wastewater in the step S1;

s4, adding 5% sulfuric acid into the divalent ion solution to adjust the pH value to 1, and obtaining silicic acid and a first sodium sulfate solution after centrifugal separation operation;

s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution;

s6, refrigerating the saturated sodium sulfate solution at-10 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, mixing the second sodium sulfate solution with the first sodium sulfate solution, and then carrying out the operation of the step S5 again.

Embodiment 2, as shown in fig. 1, this embodiment discloses a method for recycling scaling resources from phosphogypsum-recycling wastewater, comprising the following steps:

s1, adding a sodium hydroxide solution with the concentration of 20% into the scale formation of the phosphogypsum recycling wastewater, wherein the mass ratio of the sodium hydroxide solution to the scale formation of the phosphogypsum recycling wastewater is 1: 0.5; stirring and dissolving at 50 deg.C for 30min, and filtering to obtain mother liquor, magnesium hydroxide solid, and calcium hydroxide solid; the main components of the mother liquor are sodium ions, hydroxide ions, silicate ions, potassium ions and the like;

s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution; the main components of the monovalent ion solution are sodium ions, potassium ions, fluorine ions and hydroxide ions; the main components of the divalent ion solution are sulfate ions, sodium ions, phosphate ions and the like;

s3, evaporating and concentrating the monovalent ion solution, and filtering to obtain a sodium fluoride and alkaline mixed solution, wherein the alkaline mixed solution is a mixed solution of potassium hydroxide and sodium hydroxide; the alkaline mixed solution can be used for dissolving the scaling of the phosphogypsum recycling wastewater in the step S1;

s4, adding 10% sulfuric acid into the divalent ion solution to adjust the pH value to 1, and obtaining silicic acid and a first sodium sulfate solution after centrifugal separation operation;

s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution;

s6, refrigerating the saturated sodium sulfate solution at-8 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, mixing the second sodium sulfate solution with the first sodium sulfate solution, and then carrying out the operation of the step S5 again.

Embodiment 3, as shown in fig. 1, this embodiment discloses a method for recycling scaling resources from phosphogypsum-recycling wastewater, comprising the following steps:

s1, adding a sodium hydroxide solution with the concentration of 40% into the scale formation of the phosphogypsum recycling wastewater, wherein the mass ratio of the sodium hydroxide solution to the scale formation of the phosphogypsum recycling wastewater is 1: 0.5; stirring and dissolving at 80 deg.C for 30min, and filtering to obtain mother liquor, magnesium hydroxide solid, and calcium hydroxide solid; the main components of the mother liquor are sodium ions, hydroxide ions, silicate ions, potassium ions and the like;

s2, carrying out nanofiltration separation on the mother liquor to obtain monovalent ion solution and divalent ion solution; the main components of the monovalent ion solution are sodium ions, potassium ions, fluorine ions and hydroxide ions; the main components of the divalent ion solution are sulfate ions, sodium ions, phosphate ions and the like;

s3, evaporating and concentrating the monovalent ion solution, and filtering to obtain a sodium fluoride and alkaline mixed solution, wherein the alkaline mixed solution is a mixed solution of potassium hydroxide and sodium hydroxide; the alkaline mixed solution can be used for dissolving the scaling of the phosphogypsum recycling wastewater in the step S1;

s4, adding 15% sulfuric acid into the divalent ion solution to adjust the pH value to 2, and obtaining silicic acid and a first sodium sulfate solution after centrifugal separation operation;

s5, carrying out membrane concentration operation on the first sodium sulfate solution to obtain a saturated sodium sulfate solution;

and S6, refrigerating the saturated sodium sulfate solution at the temperature of-5 ℃ for 2h to obtain mirabilite and a second sodium sulfate solution, mixing the second sodium sulfate solution with the first sodium sulfate solution, and then performing the operation of the step S5 again.

Dissolving scale of the phosphogypsum reuse wastewater by using a strong base solution to obtain magnesium hydroxide solid and calcium hydroxide solid, separating a mother solution into a monovalent ion solution and a divalent ion solution to obtain sodium fluoride and an alkaline mixed solution from the monovalent ion solution, and obtaining silicic acid and mirabilite from the divalent ion solution; the recovery operation of various mineral resources in the scale formation of the phosphogypsum recycling wastewater is realized, and the waste of the mineral resources is avoided; and the whole recovery process is simple to operate, convenient and quick, and low in cost, so that the difficulty in recovering minerals in the scale of the phosphogypsum recycling wastewater is reduced, and the recovery utilization rate of mineral resources is improved.