From battery-grade lithium salts (Li₂CO₃, LiOH·H₂O) to Ni / Co / Mn sulfate crystallization and LIB black-mass hydrometallurgy — engineered for >99.5% purity, ppm-level impurity ceilings (Na, Fe, Ca, Mg) and the inverse-solubility behavior that defines Li₂CO₃ crystallizer selection.
Battery-grade production imposes purity, corrosion and crystal-size constraints that ordinary evaporation equipment cannot meet. These four constraints define every design decision on this page.
Cell manufacturers demand >99.5% product purity with magnetic-metal and alkali-metal ceilings measured in ppm — Na, Fe, Ca, Mg, Cu each <10 ppm for Li₂CO₃, and Na <20 ppm, Fe <10 ppm for LiOH·H₂O. This constrains materials, wash design and mother-liquor purge strategy from day one.
Li₂CO₃ solubility falls from ~1.54 g/100 mL at 0 °C to ~0.72 g/100 mL at 100 °C — the opposite of ~95% of other industrial salts. Crystallization therefore runs hot (80–95 °C), where the lowest solubility coincides with the highest scaling risk on heat-transfer surfaces.
Concentrated LiOH (>10%) attacks 316L stainless steel, especially above 60 °C — demanding nickel alloys for wetted parts and careful control of chloride traces carried in from spodumene or brine feeds.
Battery-grade NiSO₄ / CoSO₄ / MnSO₄ for precursor synthesis targets D50 of 200–500 μm with narrow PSD (Cv < 40%); tap density ≥1.2 g/cm³. Fluidized-bed (Oslo) crystallizers operating at 0.02–0.05 m/s, residence 4–24 h, are selected where DTB (1–2 m/s) cannot reach the size target.
Cathode plants turn their sodium load into value with a sequenced train – heavy-metal recovery, ammonia removal, then MVR evaporation crystallization producing saleable sodium sulfate and reusable condensate. Reference systems
Battery-grade lithium carbonate plants built on MVR evaporation, hot precipitation crystallization, sodium sulfate by-product recovery and rotary drying – 30,000 TPA reference practice.
Evaporation and concentration of lithium precipitation mother liquor recovers residual lithium, crystallizes sodium sulfate by-product, and returns clean condensate — the MVR-based route to closing the lithium and sodium balance.
Every lithium stream starts as ore chemistry or recycling chemistry. The route to battery-grade product runs through concentration, impurity removal and crystallization stages that we configure around your feed.
Indicative sulfate-route flowsheet — each block is configured from your feed assay, impurity profile and target crystal spec.
An indicative sulfate-route lithium carbonate flowsheet: Li₂SO₄ solution (40–60 g/L Li⁺, from spodumene roasting or LIB leachate) → MVR concentration to ~25–35 g/L Li⁺ → Na₂CO₃ reaction at 80–95 °C → hot DTB crystallization (residence 4–8 h, target crystal 100–200 μm) → centrifuge + hot deionized water wash → battery-grade Li₂CO₃. Mother liquor Na₂SO₄ recovery by FC or DTB crystallization as a by-product.
Five product classes dominate battery-material crystallization. Each row links solubility behavior, key challenge, indicative route and material of construction.
| Product | Solubility Behavior | Key Challenge | Typical Route | Material |
|---|---|---|---|---|
| Li₂CO₃ (battery grade) | Inverse solubility (1.54 → 0.72 g/100 mL, 0 → 100 °C) | Hot crystallization at 80–95 °C; Na ceiling <10 ppm | Hot DTB Continuous | 316L |
| LiOH·H₂O | ~12.8 g/100 mL at 20 °C; strong alkalinity | Monohydrate control; intergranular corrosion of SS | Vacuum Cooling / FC | Ni-200 / Ni-clad |
| Battery-grade NiSO₄ / CoSO₄ / MnSO₄ | Rising solubility; target D50 200–500 μm | Narrow PSD (Cv < 40%); tap density ≥1.2 g/cm³ | Oslo Fluidized-Bed | 316L / Duplex |
| Ternary precursor wastewater | Mixed sulfate + NH₄⁺ (Na + Ni + Co + Mn) | Sulfate purge; ammonia recovery; ZLD mandate | FC + ZLD | Duplex 2205 |
| LIB black mass leachate | Acidic (pH 1–3); multi-metal (Li + Ni + Co + Mn + Al + Cu) | SX raffinate Na₂SO₄ evaporation, ~15–25% TDS | MVR Concentration | Titanium / Duplex |
Preliminary screening only. Battery-grade product specifications vary by cell chemistry and customer. Final configuration requires laboratory solubility data, impurity profiling, crystallization trials and project-specific engineering evaluation.
Evaporation and crystallization stages must integrate cleanly with leaching, extraction and precursor synthesis — not sit as isolated islands at the end of the flowsheet.
MVR concentration of sulfuric-acid leachate ahead of impurity removal — recovering acid value and reducing neutralization reagent consumption before lithium precipitation.
Solvent-extraction raffinate carries Li⁺ with Na₂SO₄ at 15–25% TDS; forced-circulation MVR evaporation concentrates lithium for carbonate conversion while crystallizing sulfate as a by-product.
Sulfate-route lithium plants generate sodium sulfate at scale; FC or DTB crystallization produces sellable Na₂SO₄ (detergent / viscose grade) instead of hazardous mixed-salt disposal.
NCM/NCA precursor synthesis discharges mixed Ni/Co/Mn sulfate mother liquors with ammonia; evaporation-to-dryness or fractional crystallization closes the water loop and recovers metal value.
Chloride, alkalinity and acidity each move the material ladder. Selection is driven by the actual feed assay at operating temperature — not by catalog default.
Economical for neutral Li₂SO₄ / Li₂CO₃ slurries at <80 °C with chloride <200 mg/L — the baseline for sulfate-route concentrators and carbonate wash circuits.
Salt-lake brines and chloride-route feeds: Duplex 2205 for Cl⁻ <1,000 mg/L; Titanium (TA2) where Cl⁻ >5,000 mg/L or acidic chloride — verified by coupon testing at your temperature.
Concentrated LiOH service above 60 °C attacks stainless steel; Ni-200 or nickel-clad plate/shell construction for evaporator, crystallizer and piping wetted parts.
Black-mass leachate at pH 1–3 with chloride traces: titanium or Hastelloy on wetted parts, PTFE-lined piping at low temperature, and corrosion allowance justified by coupon data.
Battery-material projects usually combine this industry hub with one or more engineered solution lines.
Honest answers on battery-material crystallization and hydrometallurgical integration.
Because its solubility falls as temperature rises — from ~1.54 g/100 mL at 0 °C to ~0.72 g/100 mL at 100 °C. Most salts dissolve more at higher temperature; Li₂CO₃ dissolves less. That reverses the usual logic of cooling crystallization: instead of cooling to grow crystals, you operate hot (80–95 °C) where solubility is lowest. The consequence is that scaling concentrates on the hottest surface — the heat-transfer wall — which is why Li₂CO₃ crystallizers need tight ΔT control, generous circulation rates and careful heater design.
Battery-grade NiSO₄ / CoSO₄ / MnSO₄ typically targets D50 200–500 μm with Cv < 40% and tap density ≥1.2 g/cm³ so the precursor co-precipitation reactor receives consistent dissolution kinetics. Oslo fluidized-bed crystallizers — 0.02–0.05 m/s fluidization velocity, 4–24 h residence — deliver the size and sphericity; DTB is chosen at 1–2 m/s circulation when 100–300 μm is acceptable and throughput dominates.
Recycled black mass is leached in sulfuric acid (often with H₂O₂) at pH 1–3, dissolving Li, Ni, Co, Mn along with Al and Cu impurities. After impurity removal and solvent extraction of Ni/Co/Mn, the raffinate carries lithium with Na₂SO₄ at 15–25% TDS. MVR concentration followed by Na₂CO₃ precipitation (or Li₂CO₃ crystallization after further purification) recovers battery-grade lithium carbonate; the sulfate stream is crystallized as a sellable by-product. Each site’s flowsheet differs by feed assay and target purity.
Yes — retrofits are one of the most common projects in this industry. Aging triple-effect evaporator trains are replaced or supplemented by MVR units (typically 200–1,500 kW per MVR unit), cutting energy consumption from 0.25–0.40 t steam per tonne water to 15–25 kWh per tonne water where electricity prices permit. Feasibility depends on available electrical headroom, boiling-point elevation of the liquor and the condition of existing vessels — a site audit establishes which effects to keep, convert or retire.
Send us your target product specification, feed composition and throughput. Within 2 business days you will receive a feasibility assessment and indicative technology route.
Send your feed characterization (TDS, COD, main salts, viscosity), throughput and product targets — we respond with a preliminary process route within two business days.
