Assay Sampling Protocols for Industrial Metal Scrap Valuation
Assay sampling protocols establish true dry weight and payable metal content, directly governing settlement values, working capital allocations, and lender borrowing base limits.
Jaw Crusher
Meaning
Primary size reduction equipment represents the initial mechanical stage used to break down large rocks and core samples in a laboratory. The jaw crusher utilizes a fixed plate and a moving plate to squeeze and fracture the rock. This action reduces the sample to a manageable size for subsequent milling or pulverising.
Crushing Motion
An eccentric shaft drives the moving jaw against the fixed plate. Rock enters the top and falls deeper as it is squeezed. Compressive force overcomes the rock’s strength, and the crushed material exits at the bottom.
Operational Settings
Technicians adjust the discharge opening to control the maximum size of the output gravel. This setting is known as the closed-side setting and determines the crushing efficiency. If the setting is too tight, the throughput drops and the machine can jam.
This requires careful adjustment based on the hardness of the rock being processed.
Mechanical Wear
The heavy steel plates are subject to extreme abrasion and impact from crushing hard minerals. This wear can introduce iron contamination into the sample, which must be considered in sensitive analyses. Regular inspection of the jaw plates ensures that they are replaced before they wear down to the cast frame.
This maintenance prevents damage to the machine and ensures a consistent particle size.