Processing technology - the IOM research on nodule processing technology included assessment of the variants of the technological processing schemes of hydrometallurgical, pyro-hydrometallurgical, acid and ammonia leaching methods. Pre-feasibility studies based on the previously selected and partly optimized technologies was accomplished, together with some alternative methods for nodules treatment and use.
The work on nodule processing involved the optimization of the existing technological schemes for extraction valuable components from polymetallic nodules, and development of the basic technological schemes for polymetallic nodules processing.
Mining technology - In order to prepare the development of mining technology the IOM works were focused on the analysis of existing subsea engineering practices and development of a conceptual design for mining system applicable for the IOM’s exploration area. The comparison of alternative design variants for the assessment of technical requirements for basic components of mining technology was carried out. Development of system of the mining complex includes mathematical modelling of mining complex systems and computer simulations of control process. Computer simulations included assessment of effects of the marine environment like waves and currents on the mining complex, movement of the mining vessel and nodule miner and effects of the movement on the vertical transport riser and its deformation. The laboratory tests have been carried out with purpose to estimate slip velocity and experimental verification of nodules vertical flow on selected lifting sub-systems. In order to research and develop nodules mining technology the IOM strategy includes the following activities:
- pre-feasibility study based on existing mining technologies;
- development of a site-specific conceptual design;
- modelling and testing of the most important sub-systems and components;
- developing an engineering design of a pilot integrated mining complex for pilot-scale experiments
It is assumed, that the most essential requirement to development of deep seabed mining system is the technical and technological adaptation of equipment characteristics to geological, geotechnical and environmental conditions of the IOM exploration area. Distribution characteristics, associated with the seabed features, bottom topography, such as the relation of nodules with topography, morphology of the seafloor, nodule size as well as mine site type influence on the method of exploitation and the environmental impacts at the seafloor and in water column must be taken into account during the development of the collector. The design solutions for preserving the environment during mining from potential adverse effects (reducing mass of sediment swirled up to the bottom near-water layer, minimizing sediment penetration and transport, process of mixing in near bottom layer) are under investigation.