ECCABOND
Eccabond is a general purpose bentonite, mainly, as its name implies, intended for bonding purposes. All Bentonite is mined in the Heidelberg (WC) area.
Eccabond F
A sodium bentonite with high bonding properties when mixed with sand, and good swelling, gelling properties. It has a very good cationic exchange capacity.
Download the specification sheet here…
Eccabond K
A sodium bentonite with high bonding properties when mixed with sand, and good swelling, gelling properties. It has a very good cationic exchange capacity.
Download the specification sheet here…
Eccabond N (with foundry properties)
A sodium bentonite with high bonding properties when mixed with sand, and good swelling, gelling properties. It has a very good cationic exchange capacity.
Download the specification sheet here…
When wetted (hydrated) the Bentonite breaks down into minute colloidal particles, therefore “wet fineness” is more important than “dry milled fineness”.
In other words the useful property of the Bentonite, i.e. the bonding is not affected greatly by the dry fineness, but the general desired fineness of the Bentonite is governed by the size of the ingredients with which it is mixed.
Applications in Foundries
Eccabond is widely used in the throughout the foundry industry.
Eccabond is particularly recommended for steel foundry use for the
following reasons:
High dry strength to prevent mould erosion.
High hot and green strength to maintain mould shape during metal solidification.
High durability to withstand the higher casting temperatures and gives a lower burnout rate.
Eccabond is also recommended for iron and ferrous applications for the following reasons:
High green strength particularly necessary with modern high pressure “boxless” moulding.
Rapid bond development for high production foundries.
Ideal hot and green strengths for easier “knockout”
Pelletisation / Briquetting
Eccabond is successfully used in the pelletising and briquetting of fine ores. This is done to convert what would otherwise be a waste product into a usable commodity.
Many ores are mined for the lumpy materials and the fines rejected due to the problems they create in production.
By simply mixing the fines with bentonite and water the mixture becomes bondable which can either be pelletised or briquetted.
The most common ore that is pelletised locally is Ferrochrome.
Eccabond is ideal for this application for the following reasons:
Excellent hot strength, i.e. the bonded fines will not break down in the
furnace, but will progress to the melting stage before breaking down.
The ability to hydrate quickly and delaminate in order to be available for bonding, due to the short mixing time and low mixing efficiency.
Civil applications
Eccabond N is widely used in civil engineering as a support fluid.
Its main use is to support the sides of panel excavations for diaphragm walls. In this application, the Eccabond N forms a barrier or “filter cake” on the sides of the excavations to prevent loss of fluid into the ground and provide a surface layer against which the pressure of the fluid can act in order to resist external pressures from the soil and groundwater.
Bentonite support fluids are also widely used in the construction of large diameter bored piles.
This application is similar to that for diaphragm wall construction except for the shape of the excavation.
Small diameter boreholes for site investigation work or other purposes are often bored through unstable strata using Eccabond N as a support fluid as an alternative to temporary casings.
Eccabond N are also used in some cases to support the excavation face in front of tunnelling machines and to transport the cuttings to de-sanding equipment where they are removed before the fluid is re-circulated for further use.
Plasticizer
Eccabond is also suitable as a plasticizer for building bricks.
It acts as a binder, but more importantly it adds plasticity thus reducing the moisture of the mix.
Reduced extrusion pressures and extended die life results. Ceramic bodies will also benefit from small additions of Eccabond, improving the number of contact points in a mix due to its extremely large surface area.
Welding Rods
Eccabond, mixed into the rod coating, binds together the various fluxing materials and acts as a suspending agent until the coating is dried.
Water Treatment
Bentonite concentrations as low as 20 – 80 ppm dispersed in water act as excellent coagulants in waste effluents. Subsequent flocculation and settling is achieved by 1 – 2 ppm dosages of a suitable polymer.
Bentonite has demonstrated removal of a wide range of contaminants
to non-detectable levels, resulting in discharge water which meets
or exceeds typical regulatory requirements.
Typical Applications: Sewage treatment, Effluent and process
water recycling.
Clarification of effluents containing oil impurities.
