Lithium Recovery Calculator: Formula, Mass Balance and Example

How to calculate lithium recovery

Final lithium recovery is the fraction of feed lithium that reaches the selected isolated product. Both inventories must use the same batch or campaign and process scope.

Use matching elemental-lithium units, such as kg Li. Product mass and lithium mass are different quantities. If a measured feed assay is expressed as elemental Li wt%, feed lithium equals dry feed mass multiplied by that percentage divided by 100. For example, 100 kg of dry feed at 3 wt% elemental Li contains 3 kg Li. This example is invented for explanation.

For lithium carbonate recovery, a mass of Li₂CO₃ is not the same mass of Li. Use a supported product assay or the calculator's supported product basis with its declared composition and purity. Do not enter kilograms of carbonate as kilograms of elemental lithium.

A simple 70% lithium recovery example

Invented demonstration data — not measurements from a paper, an experiment or a plant.

Lithium in feed

3.00 kg Li

Lithium in selected product

2.10 kg Li

Final recovery

(2.10 ÷ 3.00) × 100 = 70%

This is the calculation behind the simple example on Home. The remaining 0.90 kg Li has not reached this selected product. That subtraction alone does not identify its destination or prove it is a measured process loss. A stream inventory is needed to separate residues, liquids, stocks, other products and any unaccounted amount.

Leach extraction versus final recovery

Leach extraction tracks lithium entering the liquid during leaching. Final recovery tracks lithium reaching the selected isolated product after the included downstream steps. Purification solids, wash water, mother liquor and bleed streams can carry lithium away from that product.

For example, a high extraction percentage does not establish the carbonate recovery percentage, product purity or saleable quantity. Compare percentages only when the material basis and scope match. The LFP recycling guide explains the process sequence.

Read the mass balance before calling the remainder a loss

In a closed, simple batch with no opening stocks or external lithium additions, feed lithium should equal product lithium plus other measured outputs and closing stocks. For a circulating campaign, opening and closing stocks, additions and recycle transfers need explicit treatment. Internal recycle is not a new external supply or a final output each time it moves.

A lithium mass balance is an accounting check. The unaccounted amount signals incomplete or inconsistent accounting; it is not automatically a measured residue loss. The tool does not force the balance to close or silently correct contradictory measurements.

How input bounds affect recovery

Each entered central value must lie within its own lower and upper bounds. The simple demonstration supplies feed bounds of 2.99–3.01 kg Li and product bounds of 2.09–2.11 kg Li. The corresponding recovery is about 69.4–70.6%, displayed to the interface's precision.

This range comes from the stated input bounds; it is not a statistical confidence interval. Changing a value without updating genuinely supported bounds can make the result unavailable. Do not widen bounds simply to obtain a preferred answer.

Recovery does not establish economic viability

A recovery percentage does not tell you whether the product meets a buyer's requirements or covers recycling costs. For that, prepare accepted dry product mass, a supported price and complete cost coverage. See battery recycling cost analysis.