Research into future production was addressed alongside basic research
Research and development continued on familiar topics. The work focused on the various phases of the current production process. New topics included examining the upcoming battery chemicals plant and the recovery of rare earth elements and uranium.
At the heart of Terrafame’s production process is bioheapleaching, a technology developed by the company itself, which is constantly being studied and developed to ensure good metal yield. In 2018, fundamental mineralogical research was resumed in order to ensure the consistent quality of ore for bioleaching. Microbiological research also continued.
Research into the operations of bioleaching and heaps also moved forward. In addition to the previously started drilling, sample analysis and column tests, the research activities included the optimisation of agglomeration, aeration and irrigation for the bioleaching heaps.
Battery chemicals plant process studies were utilised for planning
In 2018, Terrafame decided to invest in a new battery chemicals plant. Its process is based on three main phases: pressure leaching, solvent extraction and crystallisation.
During the year, research was carried out on the pressure leaching and solvent extraction processes in order to confirm the right design criteria and equipment dimensions for the battery chemicals plant. Technological solutions commonly used in the industry were selected for the plant, and contracts were signed with reliable equipment suppliers.
A laboratory-scale trial of the extraction process was completed
In December 2017, Terrafame was authorised by the Radiation and Nuclear Safety Authority to carry out a laboratory-scale trial on the extraction process for uranium recovery. The trial was launched in early 2018 and completed in late summer.
The trial was used to obtain information and experience on the operation of the liquid-liquid extraction process for uranium recovery, while at the same time optimising the process parameters well before the uranium recovery plant will possibly be commissioned. Terrafame filed a permit application for uranium recovery with the Government of Finland in October 2017.
Terrafame’s goal is to utilise metals from ore with the highest possible efficiency. In addition to uranium recovery, the extraction process trial provided the opportunity to study the recovery of rare earth elements.
Research into landscaping decommissioned mining sites was expanded
Bioleaching and waste rock areas, as well as process precipitate ponds, are closed and landscaped as soon as their production use has ceased. Therefore, research on covering and landscaping such areas forms a part of long-term development at Terrafame. In the research, the aim is to identify environmentally safe ways to close and landscape areas, as well as to look for natural sealing materials for cover structures where possible.
In 2018, new types of structures were used to construct another set of surface structure trial in the secondary leaching area for studying various ways of covering waste rock areas. Surveillance of the trial constructed previously in the secondary leaching area continues. In the process precipitate ponds, research was started in 2016, and its surveillance continued in 2018.
A three-year trial to examine the utilisation of waste rock was launched in autumn 2017, and the work continued in the summer of 2018. The aim of the research is to collect data for the development and inspection of base structures in waste rock areas as well as to investigate the possibilities of commercially utilising the small contents of valuable substances in waste rock.