Читать книгу Introduction to Ore-Forming Processes - Laurence Robb - Страница 15

Throughout this book reference is made to the term “ore deposit” with little or no consideration of whether such occurrences might be economically viable. Although such considerations might seem irrelevant in the present context, it is necessary to emphasize that professional institutions now insist on the correct definition and usage of terminology pertaining to exploration results, mineral resources, and ore reserves. Such terminology should be widely used and applied, as it helps to reduce the incorrect, and sometimes irresponsible, usage of terminology in reports on which, for example, investment decisions might be based. Correct terminology can also assist in the description and identification of genuine ore deposits from zones of marginal economic interest or simply anomalous concentrations of a given commodity.

Although the legislation that governs the public reporting of mineral occurrences varies from one country to another, there is now reasonable agreement globally on a definition of terms. It is widely accepted that different terms should apply to mineral occurrences depending on the level of knowledge and degree of confidence that is associated with their quantification in terms of grade and mass/volume. Figure 3 is a matrix that reflects the terminology associated with an increased level of geological knowledge and confidence, and modifying factors such as those related to mining techniques, metallurgical extraction, marketing, and environmental reclamation. Exploration results can be translated into a mineral resource once it is clear that an occurrence of intrinsic economic interest exists in such form and quantity that there are reasonable prospects for its eventual exploitation. Such a resource can only be referred to as an ore reserve if it is a part of an economically extractable measured or indicated mineral resource. One problem with this terminology is that an economically extractable ore deposit in a developing world artisanal operation may not be viable in a technically developed economy, and vice versa. The term “ore deposit” has no significance in the professional description of a mineral occurrence and is best used simply as a descriptive or generic term.

Figure 3 Simplified scheme illustrating the conceptual difference between mineral resources and ore reserves as applied to mineral occurrences. The scheme forms the basis for a more unified description of ore deposits as now required in terms of legislation that has been passed in most major mineral producing jurisdictions.