Volcanic ash can become a cheap raw material for cement
The foundation and visible symbol of progress is the erection of new objects, and the cornerstone of any modern construction is access to quality cement. The creation of cement requires so much energy that its production accounts for up to 5% of the total volume of global CO2 emissions into the atmosphere. This direction needs optimization and the Massachusetts Institute of Technology proposed the idea of using volcanic ash.
Ashes from volcanoes as raw materials exist almost in all regions of the planet, they are filled with slopes and calderas of long extinct volcanoes and it is thrown out from the vents of the active ones. At the same time, the components in the volcanic substance have already undergone a kind of treatment with high temperatures and pressure in the bowels of the earth – in analogy with how cement constituents are prepared in industry. There is an opportunity to take finished raw materials and save on costs.
Ashes before adding to the cement mixture must be shredded, and here there is a vast scope for experimentation. American scientists have conducted hundreds of experiments with granule sizes from 17 to 6 μm and ash concentration in cement from 10 to 50%. The best result was a reduction in total energy costs for the organization of the entire range of construction works by 30%, in practice, everything will depend on the specific conditions at the site.
The authors of the idea emphasize that ash does not improve the quality of cement, but serves as a cheap natural component that can replace man-made, energy-intensive production. By eliminating this process from the general production chain, it is possible to obtain a minimization of resource consumption and a reduction in emissions to the atmosphere. And the rest is a matter of technique.