This document sets out the basic methods for sampling copper, lead, zinc and nickel concentrates from moving streams and stationary lots, including stopped-belt sampling, to provide samples for chemical analysis, physical testing and determination of moisture content, in accordance with the relevant International Standards. Where the concentrates are susceptible to significant oxidation or decomposition, a common sample that is sufficiently representative, i.e. unbiased and sufficiently precise, is used for moisture determination and chemical analysis to eliminate bias (see ISO 10251). Any large agglomerates (>10 mm) present in the primary sample are crushed prior to further sample processing. Sampling of concentrates in slurry form is specifically excluded from this document.
Stopped-belt sampling is the reference method for collecting concentrate samples against which mechanical and manual-sampling procedures can be compared. Sampling from moving streams is the preferred method. Both falling-stream and cross-belt samplers are described.
Sampling from stationary lots is used only where sampling from moving streams is not possible. The procedures described in this document, for sampling from stationary lots, only minimize some of the systematic sampling errors.