Selecting the visible material.
Testing the prepared lot.

What the sorter is looking for

Hand sorting is a visual selection stage. The aim is to separate pieces that fit the intended material selection from visibly unsuitable rock, stained pieces or mixed material, according to the agreed grade approach.

Colour, visible inclusions and the character of a broken surface can help guide selection. A white-looking piece alone does not establish talc purity or suitability for a particular application.

Keep size and grade separate

Screening separates sizes; sorting separates visual selections. A smaller fraction may still contain suitable talc, while a large lump may contain unwanted associated material. Both need to be evaluated against the intended specification.

What hand sorting cannot establish

Manual sorting cannot quantify talc content, establish an optical test value or demonstrate the absence of asbestos. Those questions need appropriate sampling and laboratory methods.

Associated minerals and variation can remain within visually similar material. Keep the sample identity and test method attached to each result.

Preserve the selected material’s identity

Agree how source material, selected grades and screened fractions are identified and kept separate through preparation. If material is combined, the sampling plan must represent the resulting offered lot.

Useful records connect the source reference, preparation lot, sample reference, laboratory report and shipment identifier. Ask which records are available for your proposed order.

A useful sorting brief

• Origin and proposed grade.
• Acceptable feed size and handling requirements.
• Visible material you want excluded, with agreed reference examples where possible.
• Optical and compositional limits, with named methods.
• Sampling and lot-identification requirements.

Reference photographs can help align visual selection once available. They should accompany a specification and sample evaluation.