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Table 1 Total cost of the recycling supernatant for KFeS2 synthesis from cold-rolling sludge

From: Low-temperature conversion of Fe-rich sludge to KFeS2 whisker: a new flocculant synthesis from laboratory scale to pilot scale

 

Reagent and processing

Cost

Usage

Subtotal cost (USD t− 1)

Recycling of used alkaline solution for KFeS2 synthesis

Fe-bearing sludge

0

0.86 t

0

Supplementary Potassium sulphide

673.3 USD t−1

1.38 t

929.15

Supplementary Potassium hydroxide

432.5 USD t−1

0.34 t

147.05

Tap water

0.28 t−1

3.1 t

0.86

Pulping

0.21 USD/kWh

0.5 kW (total 1 h)

0.11

Hydrothermal reaction

0.21 USD/kWh

30 kW (total 24 h)

151.2

Drying

0.21 USD/kWh

6 kW (total 20 h)

25.2

Total cost

1253.57