An efficient milling-assisted technology for K-feldspar processing, industrial waste treatment and CO2 mineralization

• An efficient milling-assisted technology to use K-feldspar and mineralize CO2.
• Facilitation the potassium extraction under mild conditions (e.g. 30–40 °C).
• A maximum potassium extraction ratio of ∼80% and CO2 mineralization ratio of ∼5%.
• Fragmentation, amorphization and lattice distortion enhance reaction activities.

This paper describes an environmentally friendly and efficient milling-assisted technology to produce soluble potassium from natural K-feldspar with the additive of calcium salts, and capture CO2 via mineralization. The milling-assisted process could facilitate the extraction of potassium from K-feldspar under mild conditions (e.g. 30–40 °C), and mineralize CO2 with reacted calcic slag. The milling-assisted and mineralization conditions (e.g. milling time and material ratio) were systematically investigated, reaching a maximum potassium extraction ratio of ∼80% and a CO2 mineralization ratio of ∼5%. Characterizations indicated that the fragmentation, amorphization, and lattice distortion of the mineral particles during milling-assisted process are responsible for the enhanced K-feldspar decomposition reactions and ion-exchange reaction with calcium salt. Reaction principles of K-extraction and CO2 mineralization are discussed, and a possible mechanism of milling-assisted process was proposed.

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