Optimising the extraction of amorphous silica by NaOH from soils of temperate-humid climate

摘要: This study focuses on optimising amorphous silica extraction from soils by using NaOH. Based the results of this test series, a method for quantifying in temperate-humid climate is proposed. All tests were carried out materials known composition (well-defined samples feldspar, clay minerals, bio-opal, gel, and mixtures these components) soil samples, to determine optimum set conditions, terms solid : solution ratio, temperature time, dissolving without considerably attacking other solid silicon compounds. A solution 0.2 m NaOH almost completely extracted silica, when applied at room ratio 1 : 400, only slightly broke down crystalline Si The predictable reproducible underestimation was considered more acceptable than variable partial dissolution silicates that occurs during higher temperatures. We therefore recommend estimate fraction.