abstract
Mine tailings (MT) waste valorization in construction materials can be one possible solution because they may allow an alternative for some applications as an important contribution for a more circular economy. The aim of this work was to study the feasibility of using a sulfidic mine tailing in the production of building materials such as ceramic roof tiles. The introduction of 5, 10 and 20% MT in ceramic roof tiles promoted an improvement on the final properties of these materials. The use of 20%MT has decreased the firing temperature from 1150o to 1050 oC, hence promoting energy savings and lower costs. Properties as density and water absorption were improved. Firing shrinkage, many times responsible for cracking, also decrease with the use of MT and, in this way, improve the production rate. The 20% MT ceramic formulation achieved the highest value of strength with lowest firing temperature. For the effects of sulphates' emission (SO2 and SO3 gases) upon firing, a solution was proposed involving their reaction with water and, through condensation, providing afterwards sulphuric acid as a process by-product. The use of high sulphide MT in ceramic roof tiles processing could be viewed as a potential safe waste management solution for these particular mine tailings.
keywords
LEACHING BEHAVIOR; DURABILITY; BRICKS
subject category
Multidisciplinary Sciences
authors
Paiva, H; Simoes, F; Maljaee, H; Yliniemi, J; Illikainen, M; Ferreira, VM
our authors
Helena Maria da Costa Paiva
Researcheracknowledgements
This experimental work was carried out under the auspices of the GEOSULF ERA-MIN project, supported by the Finnish Funding Agency for Technology and Innovation (Tekes), Portuguese National Funding Agency for Science, Research and Technology (FCT) and the National Centre for Research and Development of Poland (NCBR), whom the authors wish to acknowledge. The authors wish also to acknowledge SOMINCOR for the supply of the mine tailings. The work was also supported by the Foundation for Science and Technology (FCT)-Aveiro Research Centre for Risks and Sustainability in Construction (RISCO), Universidade de Aveiro, Portugal [FCT/UIDB/ECI/04450/2020].