Recovery of phosphorus values and salt impurities from aqueous waste streams
AssigneeMonsanto Technology LLC
InventorsChil Y. Choi, Gregory A. Hartmann, Peng Lei, William Poncez, Peter E. Rogers, William A. Scholle, Lowell Smith, Robert B. Weisenfeld, Fuchen Liu, Chen-Hsyong Yang
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Abstract
The present invention generally relates to processes for recovery of phosphorus values and salt impurities from aqueous waste streams. In particular, the present invention relates to processes for recovery of phosphorus values and salt impurities from aqueous waste streams generated in the manufacture of phospho-herbicides, including N-(phosphonomethyl)glycine and glufosinate.
Claims24
1-57. (canceled)
A process for recovery of phosphorus values and salt impurities from an aqueous waste stream comprising one or more organic phosphorus compounds and salt impurities, the process comprising:
- oxidizing one or more compounds containing phosphorus and organic carbon present in a feed stream comprising components of the aqueous waste stream to produce a phosphate-containing cake, wherein the one or organic phosphorus compounds are selected from the group consisting of N-(phosphonomethyl)glycine (glyphosate) and salts thereof, N-(phosphonomethyl)iminodiacetic acid (PMIDA) and salts thereof, aminomethylphosphonic acid and salts thereof, hydroxymethylphosphonic acid and salts thereof, N-formyl-N-(phosphonomethyl)glycine and salts thereof, N-methyl-N-(phosphonomethyl)glycine and salts thereof, methyl aminomethylphosphonic acid and salts thereof, and combinations thereof.
A process for recovery of phosphorus values and salt impurities from an aqueous waste stream comprising one or more organic phosphorus compounds and salt impurities, the process comprising:
- concentrating the aqueous waste steam to form at least a portion of a feed stream comprising components of the aqueous waste stream;
- and
- oxidizing one or more compounds containing phosphorus and organic carbon present in a feed stream comprising components of the aqueous waste stream to produce a phosphate-containing cake, wherein the one or organic phosphorus compounds are selected from the group consisting of N-(phosphonomethyl)glycine (glyphosate) and salts thereof, N-(phosphonomethyl)iminodiacetic acid (PMIDA) and salts thereof, aminomethylphosphonic acid and salts thereof, hydroxymethylphosphonic acid and salts thereof, N-formyl-N-(phosphonomethyl)glycine and salts thereof, N-methyl-N-(phosphonomethyl)glycine and salts thereof, methyl aminomethylphosphonic acid and salts thereof, and combinations thereof, and wherein oxidizing one or more compounds containing phosphorus and organic carbon comprises heating the feed steam by contact with an oxygen-containing gas stream.
Dependencies are inferred from the claim text.