The worldwide demand for nickel (Ni) is experiencing an unprecedented growth under current industrial and economic pressures. The European Innovation Partnership (EIP) classified Ni as a raw material with high economic importance. However, mine production mainly takes place outside of the European Union, whose mine output (in New Caledonia, Greece, Spain and Finland) represents only 8.6% of total world production.

Nickel-rich soils, such as ultramafic or serpentine soils (unattractive for agriculture in terms of fertility and productivity) are abandoned by local farmers, but have a high potential for metal recovery with application in metallurgical processes. Technologies are lacking to exploit primary sources (such as ultramafic soils) in which Ni is present at significant levels (1 500-4 000 mg kg-1), but where its extraction by conventional mining processes is not economically viable.

New means of metal extraction, recovery or recycling are therefore urgently needed to reduce the dependence of the EU on imports from metal-producing countries. Phytomining or agromining is a non-destructive approach with good potential for the recovery of high-value metals (e.g. Ni) from sub-economic ores.

LIFE - AGROMINE aims to demonstrate a non-destructive phytomining approach for the recovery of high-value metals (e.g. Ni) from sub-economic ores. The project’s approach will use plants to accumulate trace metals from soils and transport them to their shoots, which can then be harvested. Phytomining or agromining therefore offers an eco-efficient alternative to classical pyro- or hydro-metallurgical processes.

The project is in line with the circular economy concept and creates a new business aimed at recovering high-value metals, ensuring the use of secondary resources that can then be reused in other production processes.

Specific project objectives are:

• The provision of ecosystem services through agro-ecological phytomining cropping systems;
• The recovery and recycling of valuable metals from Ni-rich soils and industrial wastes (e.g. from steel industry, Ni refining, automotive and aeronautic industries);
• The use of by-products generated through the metal recovery process to improve soil fertility;
• The environmental viability of nickel phytomining (assessed through Life Cycle Assessments (LCAs), energy balance, monitoring of greenhouse gas emissions and carbon storage, and via the monitoring of the invasiveness of serpentinophyte plants and impacts on local biodiversity);
• The socio-economic viability of phytomining (assessed through the realisation of cost analyses of the phytomining chain);
• Improvements in soil quality and function, and carbon storage, after implementing phytomining cropping systems, in conformity with the Soil Thematic Strategy (COM(2012) 46); and
• The conservation of rare and endangered metallophyte species after their introduction into cropping systems through the constitution of germplasm banks and the careful use of native and adapted wild species to agricultural and land remediation sites.

Expected results:

• Five field trials established across Europe (Albania, Austria, Greece, Spain and France), covering distinct climate and soil conditions;
• A complete evaluation of the phytomining cycle;
• Demonstration of additional ecosystem benefits that can be obtained during the phytomining cycle (e.g. improved soil quality and fertility, biodiversity, and carbon sequestration), through monitoring actions and training;
• Beneficial effects for different parameters are expected such as the soil organic matter content (increase of 10-50%), the water retention (increase of 10-30%), a reduced soil compaction, an increase of 5-20% in microbial respiration and enzymatic activities, a greater macroinvertebrate diversity (increase 5-10%) and an increase of 10-20% of plant biomass production to name but a few;
• Biomass valorisation will demonstrate the potential for using harvested biomass from each target plant species for Ni-products and energy provision. An LCA will evaluate if and how the phytomining cycle is capable of reducing pressure on raw materials and contributing towards sustainable soil management, without negative impacts on the environment; and
• The economic viability of the phytomining process will be quantified.