Parameter | Results of Analyses | National Quality Standard | Methods of Analyses | ||
Raw material | Lab-scale extraction | Scale-up extraction (120 kg∙batch−1) | |||
pH H2O | 9.52 | 12.2 | 12.7 | - | pH meter |
Nitrogen (%) | 0.02 | 0.01 | 0.01 | - | Kjehdahl |
P2O5 HCl 25% (%) | 0.53 | 0.11 | 0.12 | - | Spectrophotometer |
K2O (%) | 0.10 | 0.12 | 0.22 | - | AAS |
Sulfur (%) | 0.1 | 0.28 | 0.22 | - | AAS |
Total SiO2 (%) | 31.4 | 10.9 | 10.1 | Min. 10 | Gravimetry |
Soluble Si (%) | 0.008 | 2.5 | 1.6 | - | Spectrophotometer |
Water content | 0.37 | 0.79 | 1.5 | Max. 5 | Gravimetry |
Organic Carbon | 0.49 | 0.24 | 0.25 | - | Spectrophotometer |
MgO (%) | 1.96 | 0.64 | 0.99 | - | AAS |
CaO (%) | 4.82 | 1.35 | 2.14 | - | AAS |
Al2O3 (ppm) | 28.16 | 8.60 | 8.97 | - | AAS |
Fe2O3 (ppm) | 20.91 | 4.4 | 7.5 | - | AAS |
Pb (ppm) | 17.1 | 20.4 | 32.6 | Max. 500 | AAS |
Cd (ppm) | 10.5 | 0.9 | 0.8 | Max. 100 | AAS |
As (ppm) | nd* | nd | nd | Max. 100 | AAS |
Hg (ppm) | Nd | nd | nd | Max. 10 | AAS |
Cr (ppm) | 326.8 | nd | 6.2 | <4% | AAS |
Ni (ppm) | 40 | 15.3 | 19.1 | <0.4% | AAS |