As far as nodule processing technology is concerned, the IOM research included the assessment of the variants of the technological processing schemes based on hydrometallurgical, pyrometallurgical, acid and ammonia leaching methods. Pre-feasibility studies based on the previously selected and partly optimized technologies were also conducted, together with some alternative methods for nodules treatment and use.
The work on nodule processing involved the optimization of the existing technological schemes used for the extraction of valuable components from polymetallic nodules, as well as the development of conceptual technology schemes intended for polymetallic nodules processing.

Mining technology - In scope of the mining technology development the IOM works were focused on the analysis of the existing subsea engineering practices and a development of a conceptual design for a mining system feasible for the IOM’s exploration area. The comparison of alternative design variants involving the evaluation of technical requirements regarding basic mining technology components was carried out. Development of a mining system includes the mathematical modelling of mining systems and computer simulations of control processes. Computer simulations included the assessment of the impacts of marine environment phenomena such as waves and currents on the mining system, the movement of the mining vessel and nodule miner and the effects of this movement on the vertical transport riser and its deformation. The laboratory tests have been carried out with a purpose to estimate slip velocity and provide an experimental verification of nodules vertical flow on selected lifting sub-systems. In order to research and develop the nodules mining technology, the IOM strategy involved includes the following activities:

  • pre-feasibility study based on the 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 an integrated pilot mining complex for pilot-scale experiments.

It is assumed that the most essential requirement applying to the development of deepsea 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 seabed features and bottom topography, such as the relation between nodules’ density and topography as well as morphology of the seafloor, nodule sizes as well as mining site characteristics all exert their influence on the exploitation method adopted. The environmental impacts at the seafloor and in water column must also be taken into account during the development of the collector. The design solutions used for preserving the environment during mining from potential adverse effects (reducing the mass of sediment swirled up into the bottom near-water layer, minimizing sediment penetration and transport, mixing processes taking place in near bottom layer) are under investigation.