African iron ore explorer and developer Genmin (ASX: GEN) has released an updated mineral resource estimate for detrital iron deposits (DID) at its wholly-owned Baniaka iron ore project in West Africa’s Republic of Gabon.
The update is based on geological information and assay data from 118 shallow, infill auger holes for a total 1,464m at the Tsengué and Bandjougoy targets, which are two of 12 major prospects of varying maturity within the project.
It shows the indicated resource at both prospects has increased from 11.6 million tonnes to 24Mt, representing an approximate 107% uplift and 38% of the total reported 63.1Mt DID estimate.
In-situ iron grade has reduced marginally from 47.2% to 46.6%, while overall contained metal has increased 3.2%.
Laboratory work on DID has shown with washing, screening and dense media separation, lump and fines iron ore products can be produced at indicative iron grades of up to 64%, with mass yields between 51% and 67%.
A pilot scale program is being conducted in South Africa on seven DID samples weighing a combined 11t in order to define engineering level process design criteria, confirm product yields and grade, and provide large product samples (greater than 500kg each) for value-in-use test work.
Genmin said resource definition drilling is ongoing at Baniaka with the aim of expanding the mineral inventory in support of a preliminary feasibility study.
The company aims to improve the geological knowledge of existing DID, oxide and primary inferred resources to a level of confidence required to achieve indicated and measured classifications.
Incorporated within the program is infill drilling required to upgrade the geological knowledge and confidence of the remaining DID resources at Bandjougoy and at Bingamba North, which are currently classified as inferred.
Most advanced project
The Baniaka project comprises the Baniaka and Baniaka West exploration licences covering a total area of 881sq km.
It is Genmin’s most advanced project and exploration since 2013 has defined a cumulative strike length of 85km of iron mineralisation, subdivided into 17 prospects.
The mineralisation comprises a surficial blanket of unconsolidated DID up to 16m in thickness and underlain by oxidised banded iron formations (BIF) ascribed to the Archaean Belinga Group (known as oxide).
The oxide extends to depths of up to 70m below surface and is underlain by fresh magnetite BIF (primary).
Auger and diamond drilling at Baniaka to date has tested approximately 29km (35%) and 14km (17%) respectively of the defined strike length, and forms the basis for the project’s mineral resource estimates.