A Geoeconomic Planning and Evaluation Model for Artisanal Small-Scale Gold Mining in Ghana

Abstract

Following calls for comprehensive National Action Plans (NAPs) that outline training programmes for the handling of mercury and strategies for reducing emissions from artisanal and small-scale gold mining (ASGM) under the Minamata Convention, other follow-up calls intensified the need for the formalisation or regulation of ASGM in the sector. Aside from the precarious emission of mercury and hazards to the environment, the ASGM sector resorts to unsafe methods for exploiting minerals due to inadequate funding. It is not surprising that anti-mining groups constantly advocate against mining in general as a result of the harm unprofessional ASGM operators expose man and the environment to. In this light, several studies have been conducted to propose safe techniques of exploiting minerals by ASGM operators and the need for governments to regulate the sector through legal instruments. Unfortunately, the problems of ASGM seem to linger on. Notwithstanding, much attention has not been given to the formulation of procedures for accurate resource estimation and subsequent feasibility studies of ASGM, which could probably be a major cause of ASGM challenges. This study proposes Inverse Distance Weighting (IDW)  technique for estimating the concentration of alluvium gold. The IDW method was successfully applied to the alluvial deposit of the Mpeasem Gold Project, and practical results were obtained for economic evaluations. The total volume of alluvial gold deposits was 3.4 Mm³ at an average grade of 0.46 g/m³. Economic evaluation yielded a net present value (NPV) and internal rate of return (IRR) of USD 2.8 M and 48%, respectively. The results indicate that reasonable data from outcrop sampling, pitting and trenching, and detailed cost estimates can present a more compelling case for funding. This way, the funding inadequacies which contribute to the use of shortcuts and unsafe tools, materials, and methods can be minimised.