초록 ▼

A method of treating mine drainage water including the step of adding a scale control agent to the mine drainage water and, optionally, adding an oxidizing agent to the mine drainage water and/or precipitating and settling the metals in their hydroxide form from the water. The treated water may be s

A method of treating mine drainage water including the step of adding a scale control agent to the mine drainage water and, optionally, adding an oxidizing agent to the mine drainage water and/or precipitating and settling the metals in their hydroxide form from the water. The treated water may be safely returned to the environment.

대표청구항 ▼

1. A method of treating mine drainage water having a pH of from 4.5 to 10, a calcium hardness greater than 100 mg/l of Ca+2, and containing metals in solution or suspension comprising:(a) adding an oxidizing agent to the mine drainage water wherein the oxidizing agent is selected from the group cons

1. A method of treating mine drainage water having a pH of from 4.5 to 10, a calcium hardness greater than 100 mg/l of Ca+2, and containing metals in solution or suspension comprising:(a) adding an oxidizing agent to the mine drainage water wherein the oxidizing agent is selected from the group consisting of peroxides, hypochlorites, permanganates, percarbonates, perborates, chromates, ozone, osmium tetroxide, sodium metaperiodate, nitric acid, nitrous acid, and persulfates, to enhance metal hydroxide precipitation; (b) precipitating and settling the metals in their hydroxide form to provide clarified water; and (c) adding a scale control agent to the clarified water to control scale deposition, wherein the scale control agent is selected from the group consisting of polymeric scale control agents, water-soluble polycarboxylates, phosphonates, organic phosphates, and sulfonates. 2. The method of claim 1, wherein the mine drainage water is from an active, inactive or abandoned coal mine or a coal refuse pile.3. The method of claim 1, wherein the mine drainage water has of from 4.5 to 10; calcium hardness greater than 100 mg/l of Ca+2 of as calcium carbonate; alkalinity greater than 100 mg/l as calcium carbonate greater than 0.5 mg/l of one or more metal ions or metal salts selected from the group consisting of iron, copper, zinc, lead, mercury, cadmium, arsenic, barium, selenium, silver, chromium, aluminum, manganese, nickel, cobalt, uranium and antimony.4. The method of claim 1, wherein the mine drainage is hard drainage water and said hard drainage water is blended with acid mine drainage.5. The method of claim 1, wherein the mine drainage is aerated prior to step (b), precipitating and settling the metals.6. The method of claim 1, wherein the peroxides are one or more selected from the group consisting of hydrogen peroxide, calcium peroxides, and benzoyl peroxide.7. The method of claim 1, wherein the hypochlorites are one or more selected from the group consisting of sodium hypochlorite and calcium hypochlorite.8. The method of claim 1, wherein the oxidizing agents are peroxides selected from hydrogen peroxide and calcium peroxide, and permanganates selected from sodium permanganate and potassium permanganate, wherein the peroxides and permanganates are applied sequentially or in combination to the mine drainage water.9. The method of claim 1, wherein the oxidizing agent is added to the drainage water at a level of 0.1 mg/l to 500 mg/l.10. The method of claim 1, wherein one or more of a coagulating agent and a flocculant are added to the drainage water in step (b), precipitating and settling the metals.11. The method of claim 10, wherein the coagulating agent is one or more selected from the group consisting of inorganic coagulants, organic coagulants, and inorganic/organic coagulant blends.12. The method of claim 11, wherein the inorganic coagulants are one or more selected from the group consisting of alum, aluminum chloride, polyaluminum chloride, aluminum chlorohydrate, ferric chloride, and ferric sulfate.13. The method of claim 11, wherein the organic coagulants are one or more selected from the group consisting of poly(diallyl dimethyl ammonium chloride), copolymers of diallyl dimethyl ammonium chloride, polyamines, and quaternized polyepichlorhydrins.14. The method of claim 10, wherein the coagulating agent is added to the drainage water at a level of from 0.1 to 100 mg/l.15. The method of claim 10, wherein the flocculant is one or more selected from the group consisting of polyethyleneoxides, non-ionic polyacrylamides, anionic polyacrylamides, cationic polyacrylamides, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, non-ionic starches, anionic starches, cationic starches, guar, and Irish moss.16. The method of claim 10, wherein the flocculant is added to the drainage water at a level of from 0.01 to 100 mg/l.17. The method of claim 1, wherein during step (b), precipitating and settling the metals, the water is placed in a settling location for from 5 minutes to 120 days.18. The method of claim 17, wherein the polymeric scale control agents are one or more selected from homopolymers and copolymers of one or more monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, acrylamide, 2-acrylamide-methyl propane sulfonic acid, ethoxylated methacrylate, itaconic acid, polyethylene glycol monomethacrylate, t-butyl acrylamide, sodium styrene sulfonate, sodium vinyl sulfonate, hydroxy propyl acrylate, hydroxy propyl methacrylate, 3-allyloxy-2-hydroxy propane sulfonic acid, vinyl phosphonic acid and their corresponding salts.19. The method of claim 1, wherein the scale control agent is one or more selected from the group consisting of poly(acrylic acid), hydrolyzed poly(maleic anhydride), a copolymer comprising acrylic acid and 2-acrylamide-methyl propane sulfonic acid, sulfonated polyphosphino carboxylic acid, phosphonocarboxylic acid (sulfonated) copolymer, acrylic acid-sulfophenylmethallyl ether copolymer, maleric anhydride-ethyl acrylate-vinyl acetate copolymer, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxy ethylidene 1,1-diphosphonic acid, amino tri(methylene phosphonic acid), orthophosphate, polyphosphates, polyether polyamino methylene phosphonates, N,N-bis(phosphonomethyl)-2-amino-1-propanol and their corresponding salts.20. The method of claim 1, wherein the scale control agent is added to the water at a level of from 0.01 mg/l to 100 mg/l.21. A method for treating mine drainage having a pH greater than 5.5, calcium hardness greater than 100 mg/l as calcium carbonate, alkalinity greater than 100 mg/l as calcium carbonate and greater than 0.5 ppm iron, as a combination of ferric and ferrous iron ions and their corresponding salts, comprising the steps, in any order, of:adding hydrogen peroxide to the drainage water at an active level of from 0.1 mg/l to 500 mg/l; transferring the water to a suitable settling location; separating solids from the water; precipitating and settling the iron and iron salts to provide a clarified water; adding one or more scale control agents selected from the group consisting of a poly(acrylic acid), hydrolyzed poly(maleic anhydride), a copolymer comprising acrylic acid and 2-acrylamide-methyl propane sulfonic acid, sulfonated polyphosphino carboxylic acid, phosphonocarboxylic acid (sulfonated) copolymer, acrylic acid-sulfophenylmethallyl ether copolymer, maleric anhydride-ethyl acrylate-vinyl acetate copolymer, 2-phosphonobutane-1,2,4-tricarboxylic acid, 1-hydroxy ethylidene 1,1-diphosphonic acid, amino tri(methylene phosphonic acid), orthophosphate, polyphosphates, polyether polyamino methylene phosphonates, N,N-bis(phosphonomethyl)-2-amino-1-propanol and their corresponding salts; and discharging the treated water to a waterway, to control scale deposition in the clarified water. 22. The method of claim 21, wherein the scale control agent is added at a level of from 0.01 mg/l to 100 mg/l.23. The method of claim 21, further comprising the step of adding a coagulant or flocculating agent, prior to the step of separating solids from the water.24. The method of claim 21, further comprising the step of aerating the water by way of a mechanical aerator, prior to the step of separating solids from the water.25. The method of claim 21, wherein the mine drainage water is blended with acid mine drainage, prior to the step of adding hydrogen peroxide.26. A method of treating mine drainage water comprising:(a) providing mine drainage water having a pH of from 4.5 to 10; calcium hardness greater than 100 mg/l of Ca+2 as calcium carbonate; alkalinity greater than 100 mg/l as calcium carbonate; and greater than 0.5 mg/l of one or more metal ions or metal salts selected from the group consisting of iron, copper, zinc, lead, mercury, cadmium, arsenic, barium, selenium, silver, chromium, aluminum, manganese, nickel, cobalt, uranium, and antimony; (b) adding an oxidizing agent to the mine drainage water wherein the oxidizing agent is selected from the group consisting of peroxides, hypochlorites, permanganates, percarbonates, perborates, chromates, ozone, osmium tetroxide, sodium metaperiodate, nitric acid, nitrous acid, and persulfates, to enhance metal hydroxide precipitation; (c) precipitating and settling the metals in their hydroxide form to provide clarified water; and (d) adding a scale control scale control agent to the clarified water to control scale deposition, wherein the scale control agent is selected from the group consisting of polymeric scale control agents, water-soluble polycarboxylates, phosphonates, organic phosphates, and sulfonates adding a scale control agent to the mine drainage water.