Corrosion monitoring in mining is the ongoing, systematic measurement and assessment of corrosion rates and the condition of metallic structures, pipelines, and equipment in order to detect deterioration, predict remaining service life, and enable timely maintenance or replacement before structural failure or operational disruption occurs. In bauxite, gold, iron ore, and diamond mining, corrosion monitoring is an integral component of asset integrity management programs, particularly given the harsh, wet, and chemically aggressive environments typical of mining operations. The primary purpose of corrosion monitoring is to generate quantitative data that enables engineers and maintenance teams to make evidence-based decisions about the timing and scope of corrosion protection interventions, thereby avoiding the twin costs of premature replacement (over-maintenance) and catastrophic failure (under-maintenance). Corrosion monitoring employs a range of techniques: corrosion coupons (metal specimens of known weight and composition inserted into process streams and retrieved periodically for gravimetric weight loss measurement); electrical resistance (ER) probes (permanently installed in pipelines or tanks that continuously measure changes in the electrical resistance of a metal element as it corrodes); linear polarisation resistance (LPR) measurements (electrochemical technique that provides real-time corrosion rate measurements); ultrasonic thickness measurement (non-destructive testing technique where ultrasonic pulse-echo equipment measures the remaining wall thickness of pipes, tanks, and vessels from the external surface without interrupting flow); radiographic inspection (X-ray or gamma-ray imaging to detect internal corrosion, pitting, and wall thinning); and online monitoring systems that provide continuous data through permanently installed sensors connected to a SCADA or asset management system. In gold heap leach and CIL operations, corrosion monitoring of carbon steel tanks and pipelines in contact with acidic or cyanide-bearing process solutions is a regulatory and safety requirement. In iron ore slurry pipelines, ultrasonic monitoring is used to track wall thinning caused by the combined effects of corrosion and erosion from the highly abrasive iron ore slurry.
