{
  "authors": [],
  "basis": {
    "capacity": "1250 kg/h technical-grade KMnO4, 10 000 t/a (ASSUMED normalisation basis)",
    "location": "generic (not chosen)",
    "operating_hours_per_year": 8000
  },
  "benchmarks": [],
  "chemistry": {
    "inputs": [
      {
        "chemical": "manganese-dioxide",
        "grade": null,
        "note": "feed:ORE: manganese ore (MnO2 concentrate), dried and ground, 0.787 kg/kg",
        "role": "feedstock"
      },
      {
        "chemical": "potassium-hydroxide",
        "grade": null,
        "note": "feed:KOH: potassium hydroxide make-up, 50 wt% solution, counted by mass of the solution",
        "role": "feedstock"
      },
      {
        "chemical": "calcium-hydroxide",
        "grade": null,
        "note": "feed:LIME: hydrated lime",
        "role": "feedstock"
      },
      {
        "chemical": "water",
        "grade": null,
        "inventory_key": "feed:PW",
        "note": "Demineralised process water to the leach",
        "role": "feedstock"
      },
      {
        "chemical": "air",
        "grade": null,
        "inventory_key": "feed:AIR",
        "note": "Roaster oxidant",
        "role": "feedstock"
      }
    ],
    "outputs": [
      {
        "chemical": "potassium-permanganate",
        "grade": null,
        "inventory_key": "product:KMNO4",
        "note": "Potassium permanganate, technical grade, to packing",
        "role": "main-product"
      },
      {
        "chemical": "wastewater",
        "grade": null,
        "inventory_key": "product:PURGE",
        "note": "Mother-liquor purge (KOH, manganate, permanganate) to effluent treatment, ~0.70 kg/kg",
        "role": "waste"
      },
      {
        "chemical": "hydrogen",
        "grade": null,
        "inventory_key": "product:H2V",
        "note": "Cathode hydrogen vented, ~8 g/kg; recovery as fuel is an open option",
        "role": "emission"
      }
    ],
    "utilities": [
      {
        "chemical": "electricity",
        "grade": null,
        "inventory_key": "feed:POWER",
        "note": "DC for the cells through rectifiers (0.55 kWh/kg AC) and auxiliaries",
        "role": "utility"
      },
      {
        "chemical": "steam",
        "grade": null,
        "inventory_key": "feed:LPS",
        "note": "LP steam 450 kPa(a): KOH evaporator, leach heating, dryer (counted as heat, kWh)",
        "role": "utility"
      },
      {
        "chemical": "cooling-water",
        "grade": null,
        "inventory_key": "product:CW",
        "note": "25/35 C (ASSUMED)",
        "role": "utility"
      }
    ]
  },
  "description": "Dried, ground MnO2 ore is roasted with concentrated KOH (recycled from the evaporator plus\n50 wt% make-up) and air in an indirectly gas-fired kiln at about 523 K, giving a potassium\nmanganate cake. The cake is leached with recycled mother liquor at 333 K; lime precipitates\nthe dissolved silicate, and the residue (unreacted MnO2, gangue, calcium silicate) is\nfiltered and washed with the evaporator condensate. The manganate liquor is oxidised to\npermanganate in divided cells (cation-exchange membrane, 2.5 V, 1000 A/m2); hydrogen leaves\nthe cathodes. KMnO4 crystallises on cooling to 303 K, is centrifuged and steam-dried. Most of\nthe mother liquor returns to the leach; a share is concentrated to 50 wt% KOH for the roaster\nand 3 % is purged. Overall 2 MnO2 + 2 KOH + O2 -> 2 KMnO4 + H2.\n\nAll flows are concept estimates from an independent sequential balance\n(scripts/kmno4_balance.py) on assumed design parameters (roaster conversion, current\nefficiency, cell voltage, mother-liquor composition, purge), anchored where possible to\npatent ranges (US 5660712, US 5011672). No electrolyte speciation or solid-liquid\nequilibrium is calculated. See DESIGN.md for every assumption and gated step.\n",
  "design_basis": {
    "assumptions": [
      "ASSUMED MnO2 conversion to K2MnO4 0.90 in the roaster at 523 K, KOH/MnO2 2.5 mol/mol (US 5011672 optimum), air O2 2.0 x stoichiometric, 25 % of the gangue silica dissolved (D-004).",
      "ASSUMED leach at 333 K with recycled mother liquor; lime 1.10 x the dissolved silicate; residue cake 0.6 kg liquid/kg solids, displacement wash recovering 90 % of the solutes (D-005).",
      "ASSUMED cell feed 6.0 wt% K2MnO4; 90 % conversion per pass; current efficiency 0.85; 2.5 V per cell; 1000 A/m2; 333 K (D-006).",
      "Mother liquor 1.5 wt% KMnO4 and 13 wt% KOH at 303 K, inside the likely ranges of US 5660712 (15-20 g/l KMnO4, 125-175 g/l KOH); centrifuge cake 6 wt% liquid; product 0.2 wt% moisture (D-007).",
      "ASSUMED mother liquor split: 3 % purge; the evaporator share set by the roaster KOH demand, concentrate 50 wt% KOH (D-008).",
      "ASSUMED duties from a lumped enthalpy balance (scripts/kmno4_balance.py): constant heat capacities, roaster losses 15 %, double-effect evaporator economy 1.8, dryer efficiency 0.65, rectifier efficiency 0.97, auxiliary power 150 kWh/t (D-009).",
      "No electrolyte thermodynamics: liquors are carried as neutral molecules; no property package covers the streams (D-010)."
    ],
    "source": "process/design-basis.yaml"
  },
  "engineering": {
    "description": "Potassium permanganate from MnO2 ore by KOH roasting and electrolytic oxidation, 1250 kg/h, concept (issue #146)",
    "name": "Potassium permanganate",
    "requires": "cheme-as-code>=0.8",
    "stage": "concept",
    "stages": [
      {
        "id": "concept",
        "title": "Concept and feasibility"
      },
      {
        "id": "basic",
        "title": "Basic engineering"
      },
      {
        "id": "detail",
        "title": "Detail engineering"
      }
    ],
    "tool": "plantcode"
  },
  "facets": {
    "feedstock_basis": [
      "mineral",
      "electricity"
    ],
    "product_classes": [
      "chemicals"
    ],
    "region": "generic",
    "unit_operations": [
      "reaction",
      "electrolysis",
      "crystallization",
      "filtration",
      "evaporation",
      "drying"
    ]
  },
  "families": [
    "inorganic-chemicals"
  ],
  "gap_count": 4,
  "gates": null,
  "id": "potassium-permanganate-1",
  "issues": {
    "closed_count": 0,
    "list_url": "https://github.com/ChemE-as-Code/process-library/issues?q=is%3Aissue%20label%3A%22process%3Apotassium-permanganate-1%22",
    "new": {
      "action": "https://github.com/ChemE-as-Code/process-library/issues/new?template=1-action-item.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1",
      "change": "https://github.com/ChemE-as-Code/process-library/issues/new?template=4-design-change.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1",
      "hold": "https://github.com/ChemE-as-Code/process-library/issues/new?template=2-engineering-hold.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1",
      "process": "https://github.com/ChemE-as-Code/process-library/issues/new?template=6-process-development.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1",
      "tq": "https://github.com/ChemE-as-Code/process-library/issues/new?template=3-technical-query.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1",
      "tracker": "https://github.com/ChemE-as-Code/process-library/issues/new?template=7-process-tracker.yml&labels=process%3Apotassium-permanganate-1&process=potassium-permanganate-1"
    },
    "open": [],
    "open_by_gate": {},
    "open_count": 0,
    "private": false,
    "repository": "ChemE-as-Code/process-library"
  },
  "keywords": [
    "potassium permanganate",
    "KMnO4",
    "potassium manganate",
    "manganese dioxide",
    "pyrolusite",
    "KOH roasting",
    "electrolytic oxidation",
    "membrane cell",
    "crystallisation",
    "potassium hydroxide recovery"
  ],
  "lca": {
    "allocation": "none",
    "backend": "factors",
    "boundary": "cradle-to-gate",
    "categories": [
      {
        "id": "climate-change",
        "method": "GWP100",
        "title": "Climate change",
        "unit": "kg CO2-eq"
      }
    ],
    "contributions": [],
    "data_sources": [],
    "factors_status": "none",
    "functional_unit": {
      "amount": 1,
      "chemical": "potassium-permanganate",
      "grade": null,
      "label": "1 kg potassium permanganate",
      "product": "KMNO4",
      "product_name": "Potassium permanganate",
      "product_title": "Potassium permanganate (technical grade) to packing",
      "unit": "kg"
    },
    "goal": "Preliminary foreground (gate-to-gate) life cycle inventory of technical-grade potassium permanganate from manganese ore by KOH roasting and electrolytic oxidation at the concept stage: which raw materials, utilities, emissions and wastes the balanced flowsheet implies per kg of product, ready to be linked to background datasets later. Flows are concept estimates on assumed design parameters (DESIGN.md D-004 to D-009).",
    "inventory": [
      {
        "direction": "input",
        "key": "feed:ORE",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.787392,
        "title": "Manganese ore (MnO2 concentrate) dried and ground",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:KOH",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.91968,
        "title": "Potassium hydroxide make-up (50 wt% solution)",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:AIR",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.876928,
        "title": "Roaster air",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:LIME",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.03204,
        "title": "Hydrated lime",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:PW",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.31347,
        "title": "Process water",
        "unit": "kg"
      },
      {
        "direction": "input",
        "key": "feed:FUEL",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.99096,
        "title": "Fired heat (natural gas, indirect firing of the roaster)",
        "unit": "kWh"
      },
      {
        "direction": "input",
        "key": "feed:LPS",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.72232,
        "title": "LP steam 450 kPa(a) (condensate returned)",
        "unit": "kWh"
      },
      {
        "direction": "input",
        "key": "feed:POWER",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.69584,
        "title": "Electric power (AC, grid)",
        "unit": "kWh"
      },
      {
        "direction": "output",
        "key": "product:KMNO4",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.0,
        "title": "Potassium permanganate (technical grade) to packing",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:RESIDUE",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.390168,
        "title": "Washed leach residue to disposal",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:PURGE",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.703496,
        "title": "Mother-liquor purge to effluent treatment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:OFFGAS",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.76686,
        "title": "Roaster off-gas to atmosphere (after the dust scrubber)",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:H2V",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.007968,
        "title": "Cathode hydrogen to atmosphere (diluted vent)",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:O2V",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.00948,
        "title": "Anode oxygen to atmosphere",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:DRYV",
        "kind": "material",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.051552,
        "title": "Dryer exhaust vapour to atmosphere",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "product:CW",
        "kind": "energy",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 2.07592,
        "title": "Cooling water return",
        "unit": "kWh"
      },
      {
        "direction": "output",
        "key": "emission:H2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.007968,
        "title": "H2 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:H2O",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 1.0401,
        "title": "H2O to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:N2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.673481,
        "title": "N2 to the environment",
        "unit": "kg"
      },
      {
        "direction": "output",
        "key": "emission:O2",
        "kind": "emission",
        "phase": "operation",
        "provenance": "assumed",
        "quantity": 0.114306,
        "title": "O2 to the environment",
        "unit": "kg"
      }
    ],
    "no_total": {
      "baseline": {
        "climate-change": {
          "gaps": 10,
          "reason": "every-contribution-a-gap"
        }
      }
    },
    "not_computed": [
      "climate-change"
    ],
    "pcf": [],
    "publishable": true,
    "result": {
      "classification": "partial",
      "gaps": 10,
      "label": "partial screening carbon footprint",
      "publication": "public"
    },
    "sources": [
      "lca/README.md",
      "lca/dataset.yaml",
      "lca/factors.yaml",
      "lca/gaps.csv",
      "lca/inventory.csv",
      "lca/lca.yaml",
      "lca/mappings.yaml",
      "lca/results.csv",
      "lca/results.md",
      "lca/uncertainty.csv"
    ],
    "totals": {
      "baseline": {}
    },
    "withheld_reason": null
  },
  "lci_gaps": [
    {
      "dataset": "potassium-permanganate-from-mno2-ore-by-koh-roasting-and-electrolytic-oxidation-1250-kg-h",
      "key": "feed:ORE",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "potassium-permanganate-from-mno2-ore-by-koh-roasting-and-electrolytic-oxidation-1250-kg-h",
      "key": "feed:KOH",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "potassium-permanganate-from-mno2-ore-by-koh-roasting-and-electrolytic-oxidation-1250-kg-h",
      "key": "feed:LIME",
      "link": "technosphere",
      "type": "input"
    },
    {
      "dataset": "potassium-permanganate-from-mno2-ore-by-koh-roasting-and-electrolytic-oxidation-1250-kg-h",
      "key": "product:RESIDUE",
      "link": "technosphere",
      "type": "output"
    }
  ],
  "maintainers": [
    {
      "name": "Artur Schweidtmann"
    }
  ],
  "maturity": "concept",
  "preliminary": true,
  "provenance": {
    "library_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
    "previews": {
      "sheets": [
        "BFD",
        "PFD"
      ],
      "source_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
      "tool": "cheme 1.6.0 (pyDEXPI 2.1.0)"
    },
    "previews_stale": false,
    "source_commit": "c3ab3488c602bc797fdc98feffd4578375150dd0"
  },
  "publication": {
    "license": "CC-BY-4.0",
    "status": "public"
  },
  "references": [
    {
      "title": "Carus, P. III; Adolf, H.; Carus, P. II (1997) Electrolytic production of potassium permanganate using a cationic membrane in an electrolytic cell. US Patent 5,660,712 (Carus Chemical Co.): leach, cell and crystalliser conditions, mother-liquor composition ranges",
      "url": "https://patents.google.com/patent/US5660712"
    },
    {
      "title": "Garcia, M. O. G. (1991) Process for producing potassium manganate. US Patent 5,011,672 (Industrial Quimica del Nalon): ore grade, KOH/MnO2 ratio, oxidation temperatures, conventional process steps",
      "url": "https://patents.google.com/patent/US5011672"
    },
    {
      "title": "Okabe, T. et al. (1976) Process for the production of alkali permanganate. US Patent 3,986,941 (Nippon Chemical Industrial Co.): electrolysis temperature and KOH effects (alternative direct route, not designed)",
      "url": "https://patents.google.com/patent/US3986941A/en"
    },
    {
      "title": "Subramanian, K.; Gomathi, K.; Asokan, K. (2008) Electrosynthesis of potassium permanganate in a cation exchange membrane cell. Ind. Eng. Chem. Res. 47(22), 8526-8532 (abstract only read; full text not accessed)"
    },
    {
      "doi": "10.1002/14356007.a22_039",
      "title": "Ullmann's Encyclopedia of Industrial Chemistry: Potassium Compounds (route reference lead from issue #146; production sections not audited in this run)"
    },
    {
      "title": "Wagman, D. D. et al. (1982) The NBS tables of chemical thermodynamic properties. J. Phys. Chem. Ref. Data 11, Suppl. 2 (formation enthalpies and Gibbs energies; recalled values to be checked)"
    }
  ],
  "repository": {
    "access": "public",
    "path": "processes/potassium-permanganate-1",
    "url": "https://github.com/ChemE-as-Code/process-library"
  },
  "representations": [
    {
      "bytes": 43209,
      "id": "BFD",
      "kind": "bfd",
      "preview": "artifacts/potassium-permanganate-1/BFD.svg",
      "source": "process/BFD.xml",
      "status": "preview",
      "title": "Block flow diagram"
    },
    {
      "bytes": 151707,
      "id": "PFD",
      "kind": "pfd",
      "preview": "artifacts/potassium-permanganate-1/PFD.svg",
      "source": "process/PFD.xml",
      "status": "preview",
      "title": "Process flow diagram"
    },
    {
      "id": "process-model",
      "kind": "process-model",
      "source": "process/flowsheet.yaml",
      "status": "viewer",
      "title": "Flowsheet and stream table"
    },
    {
      "id": "equipment-list",
      "kind": "equipment-list",
      "source": "equipment/equipment-list.yaml",
      "status": "viewer",
      "title": "Equipment list"
    },
    {
      "id": "lca",
      "kind": "lca",
      "source": "lca/lca.yaml",
      "status": "viewer",
      "title": "Life cycle assessment"
    }
  ],
  "summary": "Technical-grade KMnO4 from manganese ore: KOH roasting with air to potassium manganate, leaching, electrolytic oxidation in divided cells, crystallisation and drying, with the KOH recycled by evaporation. Concept stage, assumed basis, preliminary gate-to-gate inventory.",
  "title": "Potassium permanganate from MnO2 ore by KOH roasting and electrolysis (1250 kg/h, concept)",
  "validation": {
    "notes": "Concept BFD/PFD with closed mass, component and element balances (cheme validate, cheme process streams: 5 blocks, 10 steps, reactive balances by extents) and a closed Faraday, charge and energy balance of the cells (cheme process cell). All flows and compositions are specified values of an independent balance (scripts/kmno4_balance.py) on assumed design parameters; the current efficiency (0.85) has no open source and the cell voltage (2.5 V) is only bracketed by a patent range. No electrolyte speciation and no multi-solute crystalliser (the core crystalliser models one solute); no property package covers the liquors, melts and solids, so the duties are a lumped script estimate. The gate-to-gate LCI is preliminary, with every background unmapped. `cheme maturity` evaluates the calculation maturity to none and warns that the concept claim exceeds the evidence (cheme.maturity-claim-exceeds): concept is kept only because the manifest schema has no lower level; read it as \"below concept: sourced screening on assumed parameters\". Independently reviewed once (reviews/2026-10-28-pfd-lci-review.md); not signed off.",
    "status": "unreviewed"
  },
  "viewer": {
    "commit": "c3ab3488c602bc797fdc98feffd4578375150dd0",
    "dirty": false,
    "sheets": [
      "process/BFD.xml",
      "process/PFD.xml"
    ],
    "skipped": [],
    "snapshot": "snapshots/potassium-permanganate-1/",
    "stale": false,
    "tool": "cheme-as-code 1.6.0",
    "views": [
      "checks",
      "streams"
    ]
  }
}