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Chemical Technology • October 2016
T
he complexity of a coal preparation plant varies accord-
ing to the nature of the rawmaterial, the requirements
for the end product and the local regulations around
water use and waste production. Some plants can require up
to 15 different stages, whilst others have significantly fewer.
One thing that many plants have in common is that the
coal is moved around the plant by slurry pumps. The pumps
are vital components in the process, as the other pieces
of equipment in the circuit – screens, hydro cyclones and
separators, for example – are all gravity-driven. It is slurry
pumps that provide the energy to lift the material to the top
of the plant, to transport it from one stage to the next, and
to carry waste slurry to the disposal facilities.
This crucial role means that the performance of pumps
has a direct impact on the efficiency of an operation. A
unit that does not perform efficiently can become a major
bottleneck in the process.
The curved vane centrifugal slurry pump was developed
in the middle of the 19th century, and the basic principle
remains the same today. However, the increasing sophistica-
tion of computational fluid dynamics (CFD) and computer-
aided design has seen engineers make significant advances
in terms of understanding the complex flow of slurries and
how it interacts with the impeller and casing inside a pump.
The research that has taken place in recent years has
allowed engineers to continue to improve the efficiency,
versatility and ease of repair of pump units and this has
meant significant reductions in the total cost of ownership
of pumps – the factor that determines the value delivered
to the customer.
It was this challenge that led the research and develop-
ment team at Weir Minerals to develop the latest model of
Warman
®
slurry pump – the Warman WBH® pump.
Over the past 50 years, Weir Minerals’ best selling pump
Pumps play a crucial role in the coal preparation process. Tony Lawson,
engineering director at Weir Minerals Europe, explains how evolving pump
design and condition monitoring are helping drive efficient production at coal
mines around the world.
Coal, pump design
and smart maintenance
PUMPS AND VALVES
The new Warman MDC pump is designed for heavy-duty slurry
applications.