The Alpine TTD Ultra-fine Air Classifier is a high performance particle separator ideal for classification of soft to medium-hard minerals at high throughputs, such as industrial fillers. The classifying wheel has a new patented design for high throughput rates and loading factors at high fineness values of up to d97 = 3.0 ?m. Due to the low pressure drop, the Alpine TTD Ultra-fine Air Classifier is considered one of Hosokawa’s most energy efficient air classifiers.