Research Article
Hydrochloric Acid Leaching Study of Rare Earth Elements from Moroccan Phosphate
Table 4
Experimental domain for the Doehlert experimental design.
| | Factor (XI) | HCl (%) | Temperature (°C) | Stirring (rpm) | S/L ratio (%) | Time (min) |
| Level 1 | −1 | 13 | 25 | 100 | 20 | 30 | Level 2 | 0 | 18 | 45 | 200 | 35 | 45 | Level 3 | +1 | 23 | 65 | 300 | 50 | 60 |
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