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CN-119774738-B - Flocculant for mine water treatment, preparation method thereof and water treatment method

CN119774738BCN 119774738 BCN119774738 BCN 119774738BCN-119774738-B

Abstract

The invention relates to a flocculant for mine water treatment, a preparation method thereof and a water treatment method, wherein the flocculant for mine water treatment contains modified polyacrylamide with the mass of water insoluble substances being equal to or more than 98%, the modified polyacrylamide is white solid with the molecular weight of 2000-4000 ten thousand, carboxyl, amino and calcium ions are introduced into a molecular chain of the polyacrylamide, and the modified polyacrylamide contains 0.32-1.60mmol of introduced amino, 0.32-1.60mmol of introduced carboxyl and 0.043-0.32mmol of calcium ions per unit gram weight. The flocculant has the advantages of effectively reducing the effluent turbidity of mine water, improving flocculation precipitation efficiency, having stable molecular structure, improving the differential impact performance of the flocculant on suspended matters resistance, reducing the dosage of the flocculant and saving cost.

Inventors

  • ZHANG WEI
  • LI TING
  • WANG DALONG
  • HAN SHAOKE
  • WANG YUCHEN
  • NAN PENG

Assignees

  • 中煤(北京)环保股份有限公司

Dates

Publication Date
20260512
Application Date
20241227

Claims (8)

  1. 1. The preparation method of the flocculant for mine water treatment is characterized by comprising the following steps of: S1, completely dissolving 50-200 parts of acrylamide monomer by using deionized water, heating the solution to 50-55 ℃, and then adding 5-7 parts of glycine into the solution to prepare a first mixed solution; Heating the first mixed solution to 70-75 ℃, and adjusting the pH value to 8.0-8.5 to prepare a second mixed solution; s2, adding the second mixed solution into an initiator, performing polymerization for 2-2.5h, adding a terminator to terminate the polymerization, and removing impurities to obtain polyacrylamide with carboxyl and amino introduced; s3, dissolving polyacrylamide with carboxyl and amino groups introduced into deionized water to prepare a third mixed solution, heating the third mixed solution to 60-65 ℃, adding 1-5 parts of soluble calcium salt, and stirring for reaction for 4-5 hours to prepare a modified polyacrylamide solution; s4, spray drying and sieving the modified polyacrylamide solution to obtain the flocculant; The flocculant contains modified polyacrylamide with the mass of more than or equal to 98 percent, and the mass of water insoluble substances in the flocculant is less than or equal to 1.0 percent; The modified polyacrylamide is white solid, and the molecular weight is 2000-4000 ten thousand; The modified polyacrylamide is characterized in that carboxyl, amino and calcium ions are introduced into a molecular chain of the polyacrylamide; wherein the modified polyacrylamide with average per unit gram weight contains 0.32-1.60 mmol of introduced amino, 0.32-1.60 mmol of introduced carboxyl and 0.043-0.32 mmol of calcium ions.
  2. 2. The method for preparing a flocculant for mine water treatment according to claim 1, wherein in S1, sodium chloride is added while glycine is added; The weight portion is 100 portions of acrylamide monomer amino acetic acid and 10 to 20 portions of sodium chloride.
  3. 3. The method for preparing a flocculant for mine water treatment according to claim 2, wherein in S2, the initiator is 0.2-0.3 part by mass of ammonium persulfate, and the terminator is sodium bisulfate, wherein the mass of the terminator is 1-10 times of the mass of the initiator.
  4. 4. The method for preparing a flocculant for mine water treatment according to claim 2, wherein in S3, the soluble calcium salt is 1-2 parts by mass of calcium chloride.
  5. 5. A method of water treatment comprising the steps of: a preliminary step of preparing a flocculant according to the preparation method of any one of claims 1 to 4; Step 1, preparing flocculant solution with the mass concentration of 0.1-0.2%; And step 2, adding the flocculant solution into mine water to be treated, uniformly stirring, keeping the concentration of the flocculant in the mine water to be 0.5-2mg/L, performing flocculation reaction for 20-30min, and collecting supernatant to obtain treated mine clear water.
  6. 6. The water treatment method according to claim 5, wherein in step 2, an auxiliary agent is added to the mine water to be treated before the flocculant solution is added, and the auxiliary agent is one of polyaluminum chloride, polyferric sulfate and lime.
  7. 7. The water treatment method as claimed in claim 6, wherein in the step 2, the auxiliary agent is polyaluminum chloride, and the amount of the auxiliary agent in the mine water to be treated is 60-100mg/L.
  8. 8. The water treatment method according to claim 5, wherein in the step 2, the concentration of the flocculant in the mine water is 1mg/L.

Description

Flocculant for mine water treatment, preparation method thereof and water treatment method Technical Field The invention relates to the technical field of mine water treatment, in particular to a flocculant for mine water treatment, a preparation method thereof and a water treatment method. Background With the sustainable development of the coal industry in China, the production of mine water is increased year by year. Mine water is complex and variable in quality and usually contains various harmful substances such as suspended matters, coal dust, salts, petroleum and the like. The presence of these substances not only increases the difficulty of mine water treatment, but also has a serious impact on its direct discharge and utilization. In order to improve the quality of mine water, protect the environment and ensure sustainable utilization of water resources, mine water treatment agents have an irreplaceable role. The treatment technology of suspended matter-containing mine water in China generally adopts a process flow of coagulating sedimentation and filtering treatment, and medicaments polyaluminium chloride (PAC) and Polyacrylamide (PAM) are cooperatively added in the coagulating sedimentation process to remove positive charges carried on the surface of suspended matters so as to enable the suspended matters to be coagulated and settled. In the field of mine water treatment, however, the conventional PAM has the following problems that (1) the coagulating sedimentation effect is poor, the operation cost is high, the color of the mine water of the coal mine is usually gray black, the main components comprise coal dust and rock dust with small particle sizes, the content of suspended matters is usually high, the concentration can reach 2000mg/L or higher, the conventional PAM has large dosage under the high suspended matter concentration, the medicament cost is high, the coagulating effect is poor, the fine suspended matters are often not completely captured, the turbidity in the water is still high, and the solid-liquid separation is realized by matching with the high-concentration PAC. (2) The difference impact resistance of suspended matters is poor, and according to the production characteristics of coal, mine water is firstly stored in a downhole water bin, is generally discharged from a valley at night, and is not discharged from a peak at daytime. Therefore, the mine water has large fluctuation of water quality and water quantity in the same day. Conventional PAM is relatively poor in adaptability to changes of suspended matters in mine water, and in addition, labor cost is increased. (3) The dissolution time is long, the dissolution is uneven, the preservation time is long, the conventional PAM dissolution time is long, 60-90min is usually required, and if the dissolution time is insufficient, the medicament may not fully exert the effect, and even the dosing equipment may be blocked. (4) The molecular structure is unstable, and in the water body with high turbidity, the traditional polyacrylamide is easy to degrade, so that the flocculation effect is affected, and the use cost is increased. Disclosure of Invention First, the technical problem to be solved In view of the defects and shortcomings of the prior art, the invention provides a flocculant for mine water treatment, a preparation method thereof and a water treatment method, which solve the technical problems of poor coagulating sedimentation effect, poor impact resistance to suspended matters difference, high treatment cost and the like of the traditional polyacrylamide in mine water treatment. (II) technical scheme In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps: In a first aspect, the embodiment of the invention provides a flocculant for mine water treatment, which comprises more than or equal to 98% by mass of modified polyacrylamide, wherein the mass of water insoluble matters in the flocculant is less than or equal to 1.0%, the modified polyacrylamide is white solid, the molecular weight of the modified polyacrylamide is 2000-4000 ten thousand, carboxyl, amino and calcium ions are introduced into the molecular chain of the polyacrylamide, and the modified polyacrylamide contains 0.32-1.60mmol of introduced amino, 0.32-1.60mmol of introduced carboxyl and 0.043-0.32mmol of calcium ions per unit gram weight. In a second aspect, the embodiment of the invention provides a preparation method of a flocculant for mine water treatment, which comprises the following steps of: S1, completely dissolving 50-200 parts of acrylamide monomer by using deionized water, heating the solution to 50-55 ℃, and then adding 5-7 parts of glycine into the solution to prepare a first mixed solution; Heating the first mixed solution to 70-75 ℃, and adjusting the pH value to 8.0-8.5 to prepare a second mixed solution; s2, adding the second mixed solution into an initiator, performing polyme