# US 4,396,439 A · Recovery and recycle of nitrate and nitrite salts from chloride containing quench bath solids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,439 A - Document ID: US4396439A - Status: Granted - Kind: A - Application number: 06/294,965 - Filed: 1981-08-21 - Granted: 1983-08-02 - Earliest claimed: 1981-08-21 - Assignees: Park Chemical Company - Inventors: Robert W. Foreman - Web page: https://patentgrep.com/patent/US4396439A ## CPC - C01B 21/48: Methods for the preparation of nitrates in general (particular individual nitrates, see the relevant groups of subclasses C01B - C01G, according to the cation) - B09B 1/00: Dumping solid waste - C01B 21/50: Nitrous acid; Salts thereof - C01D 9/00: Nitrates of sodium, potassium or alkali metals in general {(preparation as fertilizers or of fertilizers containing them C05D5/00)} - C21D 1/46: Salt baths - Y02P 10/20: Recycling - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - B09B: DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR - C01D: COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides C01B17/22; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia and cyanogen, containing nitrogen and other non-metals C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; phosphides C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method is provided for the recovery and recycle of nitrate and nitrite salts present in environmentally hazardous chloride containing quench bath solids, comprising the steps of leaching the solids with hot water to provide an aqueous leachate that depletes the hot water soluble content of the solids, clearing the resulting aqueous leachate of solids, and recycling it while hot into a fused quench bath. ## Claims ### Claim 1 A process for the recovery and recycle of nitrate and nitrite salts present in chloride containing quench bath solids in the form of difficultly breakable environmentally hazardous, rock-like masses, comprising the steps of leaching the solids with hot water to provide an aqueous leachate that depletes the hot water soluble content of the solids, clearing the resulting aqueous leachate of residual solids, delivering the leachate while hot into a fused quench bath, and recovering the residual material in the form of hand-crushable solids that are environmentally safe for disposal. ### Claim 2 (depends on 1) A process according to claim 1 where the solids are leached with hot water in the amount of at least about 0.3 part by weight of water per part by weight of solids under conditions such that the nitrate and nitrite content present in the solids is depleted below about 20% by weight. ### Claim 3 (depends on 2) A process according to claim 2 where the leaching step is carried out at the boiling point of the leaching mixture. ### Claim 4 (depends on 2) A process according to claim 2 where the leaching step is carried out for at least one hour. ### Claim 5 (depends on 2) A process according to claim 2 where the partical size of the solids subjected to leaching is about one inch or finer. ### Claim 6 (depends on 2) A process according to claim 2 where the amount of hot water is in the range from about 0.3 part to about 0.8 part per part of solids. ### Claim 7 (depends on 1) A process according to claim 1 where the solids contain sodium chloride and potassium chloride and the solids are leached with hot water in the amount of at least about 0.3 part by weight of water per part by weight of solids under conditions such that the chloride salt content of the solids is raised above about 80% by weight. ### Claim 8 (depends on 7) A process according to claim 7 where the leaching step is carried out at the boiling point of the leaching mixture. ### Claim 9 (depends on 7) A process according to claim 7 where the leaching step is carried out for at least one hour. ### Claim 10 (depends on 7) A process according to claim 7 where the particle size of the solids subjected to leaching is less than about one inch. ### Claim 11 (depends on 1) A process according to claim 1 where the leachate is filtered while hot. ### Claim 12 (depends on 11) A process according to claim 11 where the filtered leachate is delivered into the quench bath directly after filtering. ### Claim 13 A process for the handling of chloride containing environmentally hazardous solids separating in a nitrate based quench bath, comprising the steps of removing the solids from the bath, cooling and comminuting the solids, leaching the resulting comminuted solids with hot water to obtain an aqueous leachate that raises the chloride content of the solids above about 80% by weight, clearing the resulting leachate while hot into a quench bath, and recovering the residual material in the form of hand-crushable solids that are environmentally safe for disposal. ### Claim 14 (depends on 13) A process according to claim 13 where the solids contain nitrate and nitrite salts and the solids are leached with hot water in the amount of at least about 0.3 part by weight of water per part by weight of solids for a time sufficient to lower the nitrate and nitrite content of the solids below 20% by weight. ### Claim 15 (depends on 13) A process according to claim 13 where the solids contain sodium chloride and potassium chloride and the solids are leached with hot water in the amount of at least about 0.3 part by weight of water per part by weight of solids for a time sufficient to raise the sodium chloride and potassium chloride content of the solids to more than 80% by weight.