Mechanical Grinding Improved Quality of Potassium-feldspar Rocks

摘要

Potassium-feldspar rocks were ground for 10, 40, 120 and 180 minutes respectively using a porcelain ball mill. The kinetics of potassium release from activated rocks and their effect on yield and nutrient uptake by grain amaranth were evaluated. Results showed that high intensive grinding could improve physicochemical properties and bioavailability of potassium-feldspar rocks. With increasing grinding time, the particle diameters were decreased, the specific surface areas were increased, and the diffraction peaks were decreased remarkably. Maximum release of acid-soluble K was obtained in all rocks during the initial stages of leaching (0-10days), but their differences narrowed down at latter stages (10-60days). The cumulative release of K from the rock treated for 180 minutes was the highest amount (5331.51 K mg/kg rocks) and was 3.75, 1.29 and 19.8% higher than the rocks treated for 10, 40 and 120 minutes, respectively. Data from pot experiment revealed that activated rocks with higher bioavailability promoted the growth and K accumulation of gain amaranth. This study indicated that mechanical activation could be an alternate technology for the efficient of using potassium-feldspar rocks for crop production.