Claims
- 1. A method of treating Bayer process red mud containing liquor comprising the steps of:adding to the red mud-containing liquor a substantially dry water insoluble high molecular weight polymer formed from a polymer emulsion of poly alkyl esters of vinylic monomers having an intrinsic viscosity in 2N NaNO3 at 30° C. of at least 18 dL/g; forming a red mud phase and a clarified liquor phase; and recovering the clarified liquor phase.
- 2. The method of claim 1, wherein the polymer emulsion is a poly(methyl acrylate/acrylic acid) emulsion copolymer, wherein the copolymer is formed from monomers having a mole ratio of methyl acrylate to acrylic acid of from about 85:15 to about 99.9:0.1.
- 3. The method of claim 2, wherein the copolymer is from about 60 to about 90 percent hydrolyzed in the liquor.
- 4. The method of claim 1, wherein a portion of the polymer added to the red mud-containing liquor is pre-hydrolyzed.
- 5. The method of claim 4, wherein the pre-hydrolyzed polymer is hydrolyzed from about 60 to about 90 percent.
- 6. The method of claim 5, wherein the pre-hydrolyzed polymer is added to the feed line and/or center well of a mud thickening vessel.
- 7. The method claim 5, wherein the pre-hydrolyzed polymer is hydrolyzed using a caustic liquor selected from the group consisting of spent liquor, washer overflow liquor and return liquor from mud lakes.
- 8. The method of claim 1, wherein the total alkalinity of the red mud containing liquor is from about 10 to about 300 grams per liter expressed as sodium carbonate.
- 9. The method of claim 1, wherein the treatment of the red mud containing liquor is conducted at atmospheric pressure and at a temperature of from about 5° C. to about 200° C.
- 10. A method for treating Bayer process red mud containing liquor comprising the steps of:adding to the red-mud containing liquor an effective amount of a substantially dry water insoluble high molecular weight polymer formed from a homopolymer emulsion wherein the homopolymer has an intrinsic viscosity in 2N NaNO3 at 30° C. of at least 15 dL/g; forming a red mud phase and a clarified liquor phase; and recovering the clarified liquor phase.
- 11. The method of claim 10, wherein the homopolymer is from about 60 to about 90 percent hydrolyzed in the red mud-containing liquor.
- 12. The method of claim 10, wherein at least a portion of the polymer added to the red mud-containing liquor is pre-hydrolyzed.
- 13. The method of claim 12, wherein the pre-hydrolyzed polymer is added to the feed line and/or center well of a mud thickening vessel.
- 14. The method claim 12, wherein the pre-hydrolyzed polymer is hydrolyzed using a caustic liquor selected from the group consisting of spent liquor, washer overflow liquor and return liquor from mud lakes.
- 15. The method of claim 10, wherein the treatment of the red mud containing liquor is conducted at atmospheric pressure and at a temperature of from about 5° C. to about 250° C.
- 16. A method for treating Bayer process red mud containing liquor comprising the steps of:adding to the red-mud containing liquor an effective clarifying amount of a substantially dry water insoluble high molecular weight polymer formed from a terpolymer emulsion wherein the terpolymer has an intrinsic viscosity in 2N NaNO3 at 30° C. of at least 15 dLg; forming a red mud phase and a clarified liquor phase; and recovering the clarified liquor phase.
- 17. The method of claim 16, wherein the terpolymer is formed from free radical polymerization of monomers selected from the group consisting of methyl acrylate, methyl methacrylate, t-butyl acrylate, t-butyl methacrylate, acrylic acid and vinyl acetate.
- 18. The process of claim 16, wherein the terpolymer is represented by the formula of p.MA/AA/X, wherein MA is selected from the group consisting of methyl acrylate and methyl methacrylate, AA is acrylic acid and X is selected from the group consisting of t-butyl acrylate, t-butyl methacrylate and vinyl acetate.
- 19. The process of claim 18, wherein the terpolymer has a mole ratio of 1-20% t-butyl acrylate or t-butyl methacrylate, 0.5-10% acrylic acid and 70%-98.5% methyl acrylate or methyl methacrylate.
- 20. The process of claim 18, wherein the terpolymer has a mole ratio of 1-20% vinyl acetate, 0.5-10% acrylic acid and 70%-98.5% methyl acrylate.
- 21. The method of claim 16, wherein at least a portion of the polymer added to the red mud-containing liquor is pre-hydrolyzed.
- 22. The method of claim 21, wherein the pre-hydrolyzed polymer is added to the feed line and the center well of a mud thickening vessel.
- 23. The method claim 21, wherein the pre-hydrolyzed polymer is hydrolyzed using a caustic liquor selected from the group consisting of spent liquor, washer overflow liquor and return liquor from mud lakes.
Parent Case Info
This application is a Division of Ser. No. 09/542,074 filed Apr. 3, 2000 Now U.S. Pat. No. 6,372,882.
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
54--4986 |
Jan 1979 |
JP |