{
  "node": {
    "id": "term:impurity-removal",
    "type": "Term",
    "label": "Impurity removal",
    "properties": {
      "id": "impurity-removal",
      "name": "Impurity removal",
      "aka": [
        "purification",
        "iron and aluminium removal"
      ],
      "section": "topic-recycling",
      "definition": "Removing copper, iron and aluminium from the leach liquor before the valuable metals are separated, typically by cementation and by raising the pH until their hydroxides precipitate. Battery-grade products need impurities in the parts per million.",
      "related": [
        "leaching",
        "solvent-extraction",
        "precipitation",
        "cementation",
        "filter-press"
      ],
      "url": "https://lemonergy.com/learn/glossary/impurity-removal/",
      "mentions": [
        "pregnant-leach-solution"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:belongsTo/term:impurity-removal/topic:topic-recycling",
      "source": "term:impurity-removal",
      "target": "topic:topic-recycling",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:relatedTo/term:impurity-removal/term:leaching",
      "source": "term:impurity-removal",
      "target": "term:leaching",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:impurity-removal/term:solvent-extraction",
      "source": "term:impurity-removal",
      "target": "term:solvent-extraction",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:impurity-removal/term:precipitation",
      "source": "term:impurity-removal",
      "target": "term:precipitation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:impurity-removal/term:cementation",
      "source": "term:impurity-removal",
      "target": "term:cementation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:relatedTo/term:impurity-removal/term:filter-press",
      "source": "term:impurity-removal",
      "target": "term:filter-press",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/impurity-removal/pregnant-leach-solution",
      "source": "term:impurity-removal",
      "target": "term:pregnant-leach-solution",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-recycling",
      "type": "Topic",
      "label": "Recycling and end of life",
      "properties": {
        "id": "topic-recycling",
        "name": "Recycling and end of life",
        "lede": "What happens to a battery after its first life: reuse, and the recycling routes that recover its materials, step by step.",
        "context": "Distinguish recovered material from a qualified product.",
        "example": "High mass recovery alone does not establish battery-grade purity or refining energy demand.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/cell-production/",
        "lesson_label": "Open process context"
      }
    },
    {
      "id": "term:leaching",
      "type": "Term",
      "label": "Leaching",
      "properties": {
        "id": "leaching",
        "name": "Leaching",
        "aka": [
          "acid leaching",
          "reductive leaching"
        ],
        "section": "topic-recycling",
        "definition": "Dissolving the metals in black mass, usually in sulfuric acid with hydrogen peroxide as a reducing agent so cobalt and manganese go into solution as their more soluble lower oxidation state. The leach liquor carries lithium, nickel, cobalt and manganese, plus impurities such as copper and aluminium.",
        "related": [
          "hydrometallurgy",
          "black-mass",
          "solvent-extraction",
          "impurity-removal",
          "bioleaching",
          "deep-eutectic-solvent"
        ],
        "url": "https://lemonergy.com/learn/glossary/leaching/",
        "mentions": [
          "oxidation",
          "cobalt",
          "pregnant-leach-solution",
          "reducing-agent",
          "manganese"
        ]
      }
    },
    {
      "id": "term:solvent-extraction",
      "type": "Term",
      "label": "Solvent extraction",
      "properties": {
        "id": "solvent-extraction",
        "name": "Solvent extraction",
        "abbr": "SX",
        "aka": [
          "liquid–liquid extraction",
          "Cyanex 272",
          "D2EHPA"
        ],
        "section": "topic-recycling",
        "definition": "Separating metals in the leach liquor by contacting it with an organic phase carrying an extractant that picks up one metal at a time, controlled by pH: manganese, then cobalt, then nickel, leaving lithium in the water. It is how recyclers reach battery-grade sulfates.",
        "related": [
          "leaching",
          "precipitation",
          "crystallisation",
          "hydrometallurgy",
          "raffinate",
          "mixer-settler"
        ],
        "url": "https://lemonergy.com/learn/glossary/solvent-extraction/",
        "mentions": [
          "cobalt",
          "pregnant-leach-solution",
          "manganese"
        ]
      }
    },
    {
      "id": "term:precipitation",
      "type": "Term",
      "label": "Precipitation",
      "properties": {
        "id": "precipitation",
        "name": "Precipitation",
        "aka": [
          "hydroxide precipitation",
          "carbonate precipitation"
        ],
        "section": "topic-recycling",
        "definition": "Recovering a dissolved metal as a solid by adding a reagent that makes it insoluble — nickel and cobalt as hydroxides, lithium as carbonate with sodium carbonate. Co-precipitating nickel, manganese and cobalt together gives a precursor directly.",
        "related": [
          "solvent-extraction",
          "lithium-recovery",
          "precursor",
          "crystallisation",
          "mixed-hydroxide-precipitate"
        ],
        "url": "https://lemonergy.com/learn/glossary/precipitation/",
        "mentions": [
          "cobalt",
          "manganese"
        ]
      }
    },
    {
      "id": "term:cementation",
      "type": "Term",
      "label": "Cementation",
      "properties": {
        "id": "cementation",
        "name": "Cementation",
        "section": "topic-recycling",
        "definition": "Removing a dissolved metal by adding a more reactive metal powder: copper comes out of the leach solution as metal while iron dissolves in its place (Cu²⁺ + Fe → Cu + Fe²⁺). It is a common first purification step in battery recycling.",
        "related": [
          "impurity-removal",
          "pregnant-leach-solution",
          "filter-press"
        ],
        "example": {
          "title": "Size the iron for a copper cementation",
          "text": "To remove 1.0 kg of dissolved copper, at least 0.88 kg of iron powder is needed, because one iron atom (55.85 g/mol) replaces each copper atom (63.55 g/mol). Plants dose more than this, since some iron also reduces ferric iron and reacts with the acid."
        },
        "url": "https://lemonergy.com/learn/glossary/cementation/",
        "mentions": [
          "recycling"
        ]
      }
    },
    {
      "id": "term:filter-press",
      "type": "Term",
      "label": "Filter press",
      "properties": {
        "id": "filter-press",
        "name": "Filter press",
        "section": "topic-recycling",
        "definition": "A stack of plates covered with filter cloth and clamped together hydraulically, into which a slurry is pumped: the liquid passes the cloth and the solids stay behind as a cake. Recycling plants use it after leaching, purification and precipitation.",
        "related": [
          "leaching",
          "impurity-removal",
          "precipitation",
          "cementation"
        ],
        "url": "https://lemonergy.com/learn/glossary/filter-press/",
        "mentions": [
          "slurry"
        ]
      }
    },
    {
      "id": "term:pregnant-leach-solution",
      "type": "Term",
      "label": "Pregnant leach solution",
      "properties": {
        "id": "pregnant-leach-solution",
        "name": "Pregnant leach solution",
        "abbr": "PLS",
        "section": "topic-recycling",
        "aka": [
          "leach liquor"
        ],
        "definition": "The solution that leaves the leach carrying the dissolved metals: lithium, nickel, cobalt and manganese, with copper, iron and aluminium as impurities. It is filtered from the leach residue and purified before the metals are separated.",
        "related": [
          "leaching",
          "lixiviant",
          "impurity-removal",
          "solvent-extraction",
          "filter-press"
        ],
        "url": "https://lemonergy.com/learn/glossary/pregnant-leach-solution/",
        "mentions": [
          "cobalt",
          "manganese"
        ]
      }
    }
  ]
}