Windhoek — Okorusu Fluorspar mine, located between Otjiwarongo and Otavi, is piloting the extraction of phosphate from mine tailings. The mined phosphates will be used as fertilisers for crops and livestock feed.
The pilot phase is being conducted jointly by the mine and the Namibian Agronomic Board, the two organisations announced this week in a statement. They also invited the Minister of Agriculture, Water and Forestry, John Mutorwa, to the mine last week to observe the innovative methods of extraction.
The next step in the process is to step up production as a continuous process in a small-scale pilot laboratory housed in two containers with the aim of ensuring that it can be a commercially feasible operation in its own right.
Calculating the feasibility of full-scale production is envisaged to take place within seven months. The project was initiated when farmers in the area realised that phosphates in the mine tailings could possibly be extracted and used as commercial fertiliser for crops in the maize triangle. The idea took hold at a time when the price of phosphate fertilisers became highly inflated and a viable alternative was needed.
The Namibian Agronomic Board approached the Okorusu Fluorspar mine to suggest a possible collaboration to explore the viability of the idea. "The Okorusu mine management are the most forthcoming people and made available at no cost as part of their social responsibility, their facilities for the project to take shape," says Christof Brock, CEO of the Namibian Agronomic Board (NAB).
"The NAB sought the services of a research and development consultant, whilst Okorusu provided the laboratory," said Brock. "The mining process at Okorusu contributes significantly to the success of this initial phase of the project, because after blasting the rock is ground quite finely, making our laboratory work that much easier," explains the research and development consultant and chemist on the project, Eben Visser.
Mark Dawe, managing director of Okorusu Fluorspar mine was encouraged by the outcome of the pilot study and is committed to lending further support in taking it to full production should full-scale production prove to be viable. "What is left to do now is calculate the cost of full-scale production to assess whether production can be sustained in the long term. We sincerely hope that this will be the case. A by-product of the laboratory process, almost by accident, is liquid calcium nitrate. Calcium nitrate is sought after in the horticulture industry, which contributes to the taste and improved shelf life of produce such as potatoes," said Brock.
The case for progressing from the existing pilot phase to full production is compelling, since there is an abundance of the phosphate compound in the tailings of the mine, the company says.
However, the feasibility study of the project at full-scale production is set to be completed over the next year and should full-scale production prove to be viable, developing the phosphate production site could be realised within three to four years.