How do you calculate assay workload hours?

Divide sample count by testing rate for base time, then multiply by one plus the prep/retest allowance. With 96 samples at 8 samples/hr and a 30% allowance, base time is 12 hr and required workload is 15.6 hr.

Why add a preparation and retest allowance?

The raw testing rate rarely includes digestion, dilution, calibration, and the inevitable reruns from out-of-control checks or matrix interference. The 30% allowance turns 12 base hours into a realistic 15.6 hours of bench time.

What is a typical assay testing rate for battery materials?

It depends on method and automation. Eight samples per hour is reasonable for a semi-automated ICP-OES line with autosampler; manual XRF or wet-chemistry titration runs slower, and high-throughput automated rigs run faster.

How do I size lab staffing from this number?

Divide required workload by available analyst hours. The 15.6 hr batch fits comfortably in one analyst's shift; once daily workload exceeds roughly 7-7.5 productive bench hours per analyst, you need a second.

Should the allowance change by sample type?

Yes. Clean recovered-metal lots may justify 15-20%, while difficult black-mass digests or high-interference leachates can push prep and retest allowance to 40-50%. Run the calculator separately per matrix for accuracy.

What is base assay testing time versus required workload?

Base time (12 hr) is pure instrument run time at the stated rate. Required workload (15.6 hr) is base time grossed up for prep and retests — the number you actually schedule against.

Battery Recycling & Materials Recovery calculator

Material Assay Workload Calculator

Material assay workload converts a queue of battery recycling samples — black mass, leach liquors, recovered metal lots — into the lab hours actually needed to clear them, including sample prep and retest overhead. QA managers and lab supervisors at recyclers use it to staff the assay bench, set turnaround commitments for payable-lot release, and decide when an ICP-OES or XRF backlog warrants a second analyst. It matters because every payable shipment of recovered nickel, cobalt, or lithium hinges on a verified assay, and a lab that quotes raw testing time while ignoring digestion, dilution, and retests will chronically miss release deadlines and stall cash flow.

What this calculator does

Estimate lab or quality hours needed for battery material assays from sample count, testing rate, and preparation allowance.
a battery recycler needs to schedule assay resources for incoming lots, black mass shipments, process trials, or recovered metal sales
It computes the total assay lab hours required to process a sample batch including preparation and retest overhead.

Formula used

Base assay testing time = assay sample count ÷ assay testing rate
Required assay workload = base assay time × preparation and retest allowance factor

Inputs explained

Battery material assay samples:
Assay testing rate:
Preparation and retest allowance:

How to use the result

Use it when staffing the assay bench, quoting lot-release turnaround, or sizing lab capacity against incoming sample volume.
It applies one flat allowance to all samples; complex matrices (high-fluoride leachates, mixed-chemistry black mass) need higher per-sample prep time than the average assumes.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate assay workload hours? Divide sample count by testing rate for base time, then multiply by one plus the prep/retest allowance. With 96 samples at 8 samples/hr and a 30% allowance, base time is 12 hr and required workload is 15.6 hr.
Why add a preparation and retest allowance? The raw testing rate rarely includes digestion, dilution, calibration, and the inevitable reruns from out-of-control checks or matrix interference. The 30% allowance turns 12 base hours into a realistic 15.6 hours of bench time.
What is a typical assay testing rate for battery materials? It depends on method and automation. Eight samples per hour is reasonable for a semi-automated ICP-OES line with autosampler; manual XRF or wet-chemistry titration runs slower, and high-throughput automated rigs run faster.
How do I size lab staffing from this number? Divide required workload by available analyst hours. The 15.6 hr batch fits comfortably in one analyst's shift; once daily workload exceeds roughly 7-7.5 productive bench hours per analyst, you need a second.
Should the allowance change by sample type? Yes. Clean recovered-metal lots may justify 15-20%, while difficult black-mass digests or high-interference leachates can push prep and retest allowance to 40-50%. Run the calculator separately per matrix for accuracy.

Last reviewed 2026-05-12.