Labtium can offer different sample preparation packages to fit the particular properties of each exploration project.
Labtium offers optionally two sample preparation packages – one for large of up to 3.5kg and one for small pulverising samples.
This package is recommended as an optional package for rock samples where the minerals are expected to be homogenously distributed after fine crushing.
Typical sample types are base metal and iron ores. The scheme for sample preparation consists of direct one–stage fine crushing using a special type of jaw crushers (e.g. Boyd; Terminator) to nominal particle size > 70 % < 2 mm, precision riffle splitting (Method 31) and pulverising the split subsample of 70 – 100g in carbon steel bowl (Method 40). This is a suitable method if crushed reject is needed for future work. The use of this method is meaningful to maximum size of 2000 g samples, because if more than 3 - 4 riffle splittings are required the representativity of the split subsample cannot be assured. For these samples Labtium recommends robotic sample preparation. For small samples less than In this package the pulverising can be done using semi-automated pulverisers. For high – precision whole rock analysis tungsten carbide (WC) pulverising must be used (43).
This package is recommended for samples where some minerals with exceptional properties (high density, coarse particle size and geometry) are present and can cause heterogeneous distribution which can be compensated by pulverising the whole laboratory sample. Typical sample type is coarse grained gold ores.
The scheme consists of standard crushing (Method 30) followed by pulverising the entire test sample (Methods 50, low chrome steel bowl) using Essa LM5 mills, avoiding any sample splitting which may deteriorate representativity of large samples. The pulverising takes place in large bowl and provides a large homogenised test sample for representative subsampling directly from the bowl without any further sample handling. The grinding action in LM5 is based on impact and hence smearing of gold particles, which are a problem with ring and disc mills, on bowl surfaces is minimised, which is an additional advantage of the technique.
If sample size exceeds 3,5 kg the sample must be split by riffle splitter after crushing or pulverised by separate millings and homogenised before subsampling to analytical sample. In this case additional charge is invoiced for each kg exceeding 3,5 kg.
If crushed reject is required for future work the crushed material can be split to two e.g. 1-2 kg subsamples by riffle splitting (Method 35) – the other for storage and the other for pulverising (Method 50).
Manual sample preparation procedure can also be tailored from individual sample preparation methods.
In all pulverising methods which are used at Labtium, cleaning of the pulverising bowl by milling of quartzite cleaner between every sample is always included.
The client is obliged to inform Labtium for any observed components in the samples causing potential occupational health e.g. asbestos, radioactivity or environmental risk beyond the normal geolaboratory operation. Labtium is entitled to cease the processing of the samples if any of these risks are observed until the process is duly modified to eliminate the risks.