silica-bonded monolithic refractories offer a number of energy-saving opportunities over refractories that are bonded
As energy prices soar, resource-intensive
industries are being increasingly challenged to find ways to save energy
wherever possible. One area for potential energy savings is in a place one
might not immediately suspect: the furnace’s refractory lining. Monolithic
refractories offer a number of significant opportunities to save energy
compared to traditional brick, and colloidal silica-bonded monolithic
refractories* offer further savings over refractories that are bonded with
*Metpump line of colloidal
silica-bonded monolithic refractories, manufactured by Magneco/Metrel.
New Energy Savings
The savings begin at the refractory
manufacturing level. Colloidal silica-bonded monolithic refractories are
manufactured without the firing, drying or other energy-intensive processes
involved in the production of brick, which the colloidal silica products
replace. As a result of lower energy costs, these products can be offered at a
lower unit cost.
For the end user, colloidal silica-bonded monolithic refractories conserve
energy in a number of ways, both before and after installation. Unlike brick
and mortar, which must be installed by hand, colloidal silica-bonded refractory
can be pumped or shotcreted to form the furnace lining. The installation
process takes fewer man-hours to complete-cutting downtime to weeks instead of
months-and results in both time and energy savings.
After installation, colloidal silica-bonded refractories normally need no more
heat for cure-out than a brick and mortar lining. They also require
substantially less heat energy for cure-out than cement-bonded refractories
because there is no chemically bonded water in the colloidal silica-bonded
Colloidal silica-bonded monolithics can be
applied to repair clean brick surfaces or as a new lining. When a brick lining
is about 60% worn away, the remaining 40% of the brick must be torn out and
discarded (if it is to be replaced by another brick lining). The energy that
went into the forming of the discarded brick is essentially thrown away, and
the process requires extra energy to tear out the old brick and replace it.
In comparison, when a colloidal silica-bonded monolithic lining is 60% worn,
the addition of the new colloidal silica-bonded material rapidly and easily
restores the lining to its original thickness. The old material must simply be
cleaned, and the new colloidal silica-bonded material bonds directly to it.
This type of bonding cannot be done with cement-bonded materials; like brick,
they must be removed completely and replaced.
Compared to low- or ultra-low cement-bonded
castables, colloidal silica-bonded refractories exhibit superior hot strength,
thermal shock and creep resistance properties, excellent erosion and abrasion
resistance, high resistance to chemical attack, and increased mechanical
strength. All of these factors result in longer life for the furnace lining,
which results in additional energy savings over time.
With better refractoriness and hot load strength, colloidal silica-bonded
refractories can be used with less cold-face cooling than more traditional
refractories. More of the processed heat can be kept in the process and not
dissipated by cooling, thus saving energy.
Colloidal silica-bonded monolithics can be used wherever acid or neutral
refractories are possible, and can be matched to the process for which they are
used as a lining. For instance, formulations have been developed for use in the
glass, steel, iron, copper, aluminum and ceramic industries. In addition,
formulations can match the demands of each respective region of a furnace to
further increase the life span of the lining.
For more information regarding energy-saving
refractories, contact Magneco/Metrel at 223 Interstate Rd., Addison, IL 60101;
(630) 543-6660; fax (630) 543-1479; e-mail firstname.lastname@example.org; or visit www.magneco-metrel.com.