Metallurgical Sample Preparation

Before sample preparation begins, samples are placed in order of priority. Samples are then jaw and cone crushed to approximately 10 mesh. Sample is then split down to about 250g and ring pulverized to 140 mesh. The rejected portion of sample is returned to the original sample bag, saved and returned to the client. Barren rock is run through the crushing equipment between samples to clean the crushers, and one sample each day/client is provided as a sample preparation blank to be run with the normal samples. During pulverization silica sand is used between each sample to clean bowl and rings to prevent salting of samples. The 140 mesh pulp sample is placed in sample envelopes and sent to the digestion room. Samples are delivered to the instrument lab and analyzed for metals (generally by ICP) and screened for any work that may be required.

For normal ore samples usually one assay ton (29.16g) of sample is weighed with approximately 100g of our standard flux mixture into 30g crucibles. Silver inquarts are added when necessary. Lead buttons are cupeled in bone ash cupels. Duplicates and controls are included in each batch of 20 samples.

Methods are also provided for the analysis of bullion, carbons, concentrates, cyanide solutions, and various other mining and milling products, which include fire assay and atomic absorption procedures.