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Sample preparation

A critical often underestimated process

Metallurgical sample preparation is a lot more than pulverising discrete samples to dust for analysis. Sample shipments are diverse from hundreds of drill core intervals, tonnes of run of mine ore, or small discrete packages. Not just solids sample either, as water, carbons, concentrates, and all manner of chemical compounds feature in a metallurgical program. Very often, samples are immediately mixed with others to form composites, thus losing the original designation. As such, fastidious care is required to ensure the samples are prepared and blended to the right specification and ALS has the facilities and expertise to carry this out.

Capability & diligence

ALS understands the importance of sample preparation in the context of a metallurgical testwork program. If we get it wrong, all of the downstream testing results become suspect, or worse, meaningless. Over crush the sample and the downstream testwork may no longer be possible. This is why ALS places such high scrutiny and diligence on our preparation process from precise inventorying and selection through to thorough blending and splitting. Clients can be confident that their samples will be selected, crushed, and blended to exact requirements.

Comprehensive Capability

ALS Metallurgy runs an entirely separate facility and team for benchscale sample preparation. It is supervised by area specific senior technicians who receive flowsheeted instructions from the metallurgists. The area is also governed by strict procedures and backed up by the ISO 9001 quality control accreditation.

The typical equipment and progression of benchscale sample preparation services is listed below:

  • Sample lay-out area for inventorying, inclusive of roller tables for layout and inspection of core trays.
  • Control/stage crushing facilities inclusive of various sized jaw crushers, Boyd Crushers, Cone crushers, all in circuit with Russel or Kason vibrating screens to remove at spec particles from crusher product.
  • A range of riffle splitters for the blending and splitting of small sample masses below 12 kg.
  • Twelve segment Rotary Sample Dividers (RSD’s) for sample masses above 12 kg. Large 18 segment RSD’s are available for sample masses above 100 kg and procedures are in place to use these units for masses up to 2,000 kg.
  • All associated weigh scales with data capture, together with bagging/labelling equipment.
  • Fully ducted dust extraction system for the safety of the employees and the environment.
  • A separate “Fibrous” facility available for processing sample containing asbestiform minerals or radio nuclides. The facility is fully contained with a high-powered extraction system together with air conditioning.

ALS can conduct bulk sample preparation of large mass parcels as required (nominally up to 200 tonnes) for large pilot programs. Facilities include:

  • Separate crushing room centered around a double decked vibrating screen. Circuits are set-up in a modular fashion depending on the number of stages.
  • Jaw crushers of various sizes, together with Westcone cone crushers are used in series with crushed product transported via Sanki conveyors between the crushers and the classification screen.
  • A 15 m Sanki conveyor takes final crushed product to a separate sealed blending room for homogenisation and splitting.
  • Parcels up to 5 tonnes can be directly split into 200 litre drums via a large rotating arm RSD. Large riffle splitting can be used if required to for further drum blending.
  • For very large 5-tonne plus parcels, blending via a skid steer loader is conducted in an approximation of the cone and quarter method. Once in drums, further blending and splitting of drums is again via riffle splitters and RSDs.
  • Both the bulk crushing and blending rooms are fitted with dedicated dust extraction systems.

Here are some frequently asked questions

Associated testwork services

Related testwork

Invariably, sample preparation is just the start of a metallurgical testwork program. Click the following links for other downstream test work services:


Click on the above links or contact us for further information. We can integrate a full program for you if required.