Dewatering capital cost

Other apphcations include dewatering extremely fine (0.1 llm) laterite leach tailings (91). These pelletizing processes should be compared in flocculant consumption and operating and capital costs with belt-filter presses. 

The capital cost included the complete powdered activated carbon system (tankage, blowers, pumps, instmments/controls, etc.), carbon feed system, sludge storage tank, filter press, O M manuals, startup and training services, no building. The O M cost covers the leachate treatment and solids dewatering. 

The capital cost includes covered tank, carhon feed system. O M costs cited are for groundwater treatment, air emissions control/treatment, sludge dewatering/disposal, and analytical. 

Belt presses have the advantage of large capacity and automatic operation. The initial capital cost is also low. They were originally developed in the pulp and paper industry. Any slurry with fibers will do well in a belt press, and high-fiber material can be added to the slurry as a filter aid for belt press operation. Today, in addition to pulp dewatering, the belt press is widely used in wastewater sludge dewatering. 

As in the case of coal, which can be pumped in very fine sizes—smaller than 100-125 p.m (mesh 140-120) and as coarse as 50 mm (2 in), all kinds of schemes and equipment have been developed. The economics of preparing the slurry at the feed point of the pipeline, and the cost of building and operating the pipeline, the capital cost of dewatering the slurry to recover the minerals in a solid state combine to define the design criteria of the pipeline and the physics of the slurry. 

Comparisons are available on the relative performance and costs for dewatering municipal sludges (2). The relative performance of different filters and conditioners on waste sludges is shown in Table 3. The same sludge was treated on two belt-filter presses, two different centrifuges, and rotary vacuum filter (75). In another study, a variable chamber filter press, fixed-volume filter press, continuous belt-filter press, and rotary vacuum filter were compared for performance, capacity, and capital and operating costs (69). 

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