Kopparhalt

Kopparhalt is a term used to describe the copper content of a material, most commonly ore or ore concentrate. It is expressed as the fraction of copper by weight, typically in percent (wt% Cu) or in grams per tonne (g/t). The concept is central to evaluating ore quality, mine planning, and metallurgical processing, because higher kopparhalt generally indicates more copper per unit of material.

Measurement and analysis of kopparhalt involve systematic sampling and laboratory assays. Common methods include fire assay with lead collection, followed by analysis with atomic absorption spectroscopy (AAS) or inductively coupled plasma techniques (ICP-OES/ICP-MS). X-ray fluorescence (XRF) can be used for rapid in-field or laboratory screening. Quality assurance and quality control (QA/QC) procedures, including certified reference materials and duplicate analyses, are standard to ensure accuracy and comparability across samples and labs.

In reporting, kopparhalt is used to express ore grade (Cu content of the ore) and concentrate grade (Cu content of the processed material). It informs economic decisions, such as cut-off grades, mine planning, and processing routes. The copper content interacts with recovery rates and processing costs; two ores with the same kopparhalt can yield different outputs if mineralogy or textural factors affect copper recovery.

Variability is common within a deposit due to geological heterogeneity. Copper occurs mostly as sulfides (e.g., chalcopyrite) or oxides, and the mineralogy influences recoverability and processing strategy. As a result, sampling programs aim to capture grade continuity and avoid bias to provide a reliable estimate of kopparhalt for planning and economic assessments.