TSX-V-listed Giyani Metals reports that the preliminary results from metallurgical test work, undertaken by Mintek, carried out at its Botswana-based K.Hill manganese project shows a high-purity manganese sulphate monohydrate (HPMSM) with less than 1% total impurity and manganese content of more than 31.5%.

These preliminary results were achieved by the evaporative crystallisation of a purified solution, with the completed activities – including leach enhancement, bulk leach, base metal precipitation, iron and aluminium precipitation – representing a number of the initial steps of the process flowsheet to produce HPMSM from the K.Hill project ore.

The completed test work also reveals 94% manganese extraction after reductive acid leach; while iron and aluminium removal after neutralisation and precipitation, are 100% and 99.5%, respectively.

In addition, secondary purification kinetic tests show nickel, cobalt and zinc can be removed to detection limits, and sulphuric acid consumption reduced to 90 kg/t of ore compared with earlier estimates of 333 kg/t.

Giyani is also undertaking ongoing field programmes, including exploration drilling programmes at an extension of the existing K.Hill project orebody and the Otse manganese prospect.

The remainder of the metallurgical test programme will focus on further impurity reductions, with the programme set to form part of the feasibility study into the K.Hill project.

The K.Hill project feasibility study reserve infill drilling is complete and assay results and an ore reserve estimate are both expected during the third quarter of this year.

Giyani reports that the related in-pit and civil geotechnical drilling, along with sterilisation drilling in the designated plant and infrastructure areas, is also progressing as planned.

Meanwhile, at the K.Hill extension project, the miner states, 13 of the planned 32 reverse circulation drill holes have been completed to date, representing 923.5 m.

At Otse, two orientation geophysical studies, using ground penetrating radar, have been completed and an induced polarisation programme will commence later this month.

CEO Robin Birchall says the completion of the reserve drilling campaign and the progress on the mineral reserve estimation will culminate in the announcement of Giyani’s maiden reserve in the third quarter.