Permission to use the attached copyrighted document provided to the U.S. EPA by email dated 

November 3, 2009 from J. Sloesen, Weir Minerals Netherlands b.v., to Steve Souders, U.S. EPA. 
GEHO® piston diaphragm pump for fly ash transportation at Bayswater Power Plant. 

GEHO® Info for sales representatives 

Volume 7, No. 2, April 1997

Dry disposal of fly ashes

Dense ash slurry benefits 

Fly and bottom ash generated by coalfired power plants is generally transported 

hydraulically, pneumatically or by 

mechanical means (trucks, conveyors), to 

ash dumps, natural ash dams or artificial 

ash dams. The hydraulic transport of fly 

ash has been largely in the form of dilute 

slurries ie. 10-30% solids by weight. 

However, continued use of dilute slurry 

pumping has been questioned and 

environmental constraints on ash disposal 

have limited the options available and 

increased costs. The problems are 

substantially eliminated by preparing ash 

slurry at high density ie. low water content 

for discharge onto a sloped disposal site 

where the deposit stabilises. 

GEHO® piston diaphragm pumps are well 

suited for transporting high concentrated 

slurries, making a "dry" disposal method 

possible. The highly concentrated, thick 

slurry runs out slowly over the disposal 

site after leaving the pipeline. Normally 

there is no water leakage, depending on 

the characteristics of the ash. The high 

density disposal method offers several 

major advantages, such as: 

• Dense fly ash slurries use significantly less water than dilute slurries. 

• The need for an ash dam water reclaim system and return water lines 

can often be avoided with the natural 

retention of slurry water by the dense 

ash slurry. 

• When used as mine backfill, it does 

not add to the mine dewatering 

capacity and solids loading of the 

mine water. 

• Dense fly ash slurries do not flow out 
 

GEHO® hydraulically driven piston pumps for fly ash pumping at 

MUJA Power Station (decommissioned). 

to form a horizontal 

surface, but create a 

shallow cone from 

the point of 

discharge. 

• A typical slope of 2-

6% will be generated in the ash 

dam; the ash will dry 

out to form a fairly 

solid surface, 

unaffected by rainfall 

(erosion) and not 

prone to dusting in 

windy conditions. 

• The energy savings 

to run pumps can amount to 50% or 

more. 

Score against conveyors 

GEHO® PUMPS has won a major 

contract to design, supply and install three 

GEHO® ZPM 800 ash transport pumps at 

Ledvice power station in the Czech 

Republic. The positive displacement 

piston diaphragm pumps will transport 

154 m3

/h of ash slurry 4,300 m from the 

power station to a 1,000 m long, 100-200 

m wide and 29 m heigh ash disposal site 

located against a 15E slope. The dense 

phase slurry will be transported through 

150 mm diameter pipes at a maximum 

solids concentration of 72% and an 

operating discharge pressure of 9.3 mpa. 

The pumps, 3 x 50% capacity, form part 

of the ash slurry preparation and transport 

system, with detailed engineering and 

construction being carried out by Chepos 

Engineering, Brno. 

The project involves the construction of 

two thermally insulated surface pipelines, 

the pumping station, the agitated slurry 

mix tank and power distribution and 

control systems. 

Rough with the smooth 

The ash disposal system is unique in that 

it is designed to handle various mixtures 

and ratios of fly ash, bed ash, bottom ash 

and desulphurisation products. These 

slurried mixtures have either settling or 

hardening characteristics. 

Complex control loops working interactively ensure that the various slurries are 

delivered to the pipeline in a condition 

which satisfies the stringent specification 

for pipeline operation and for slurry 

disposal. Controls and operation 

procedures are designed to prevent 

pipeline blockage, to clear slurry from the 

pipeline by using water and for pipeline 

drainage with the help of compressed air. 

The plant and component design is based 

on sample testing by GEHO®. During the 

plant proving phase, the slurry properties 

will be modified with a view to optimize 

the performance of the overall ash 

disposal system. 

This project follows the commissioning of 

the Bayswater fly ash disposal plant in 

New South Wales and of the MUJA fly 

ash pumping plant in Western Australia. 

Weir Minerals Netherlands b.v. 

P.O. Box 249, NL-5900 AE Venlo 

Phone: +31(0)77-3895200 

Fax: +31(0)77-3824844 

Email: weir@weirminerals.com

Website: www.weirminerals.com

Copyright © 1997, Weir Minerals Netherlands b.v. All 

rights reserved.