1. REFRACTORY CASTABLES

Castable refractory products are non-metallic materials that have chemical and physical properties used for creating heat-resistant structures that retain and insulate. Due to their high resistance to heat and thermal shock, you can use castable refractory cements and other products to build kilns and furnaces. Refractory castables can be used to create the monolithic linings within all types of furnaces and kilns. They can be further classified into the following sub-categories: conventional, low iron, low cement, and insulating for installation either by gunning or manually. There is a wide variety of raw materials that refractory castables are derived from, including chamotte, andalusite, bauxite, mullite, corundum, tabular alumina, silicon carbide, and both perlite and vermiculite can be used for insulation purposes.

• CONVENTIONAL DENSE REFRACTORIES

Conventional dense castables are created with high alumina cement, and can withstand temperatures from 1300^oC to 1800^oC. These refractory castables are great for common furnace applications, burner blocks, speciality muffle furnaces and boiler work. Resistance is a key quality that varies with the choice of materials, resulting in abrasion, thermal shock and slag attack. Casting and gunning techniques are the method of installing the materials. For the ease of castable placement, gunning materials and water are combined together at the gunning equipment’s nozzle. This is a great method of placement for bulk materials, in cases when circumstances make formwork overly time consuming or simply impractical. In general, the method of installation will depend on cost and accessibility.

• INSULATING 

Another product that we supply is the castable refractories that are low density. These insulating castables pose very low thermal conductivity and are utilized for either high temperature face work or when used for a backup lining, which is found behind dense castables or brick work. Here, the insulating castables are able to decrease the lining’s overall density or the cold face temperature. Their strength, which ranges from low to medium, is based on the fact that their density is low and is the main reason that they are not resistant to abrasion. They are most suitable where they do not have to stand up to much wear and tear.

• LOW CEMENT

This type of refractory castable is prepared with a lower amount of cement than the standard dense castable is normally created with. Low cement castable refractories fluctuate in alumina content, which provides exceptional physical properties, including low porosity, great abrasion properties and high vigour. These products will commonly necessitate installation that is controlled, however, the big advantage of low cement castables is that they are easily pumped into position, and some may not require vibration, because they are free flowing.

2. Refractory Cement / Mortars

Refractory cement is used for building brick or stone fireplaces, barbecues or other installations which are subjected to intense heat. While refractory cement is similar to standard cement in how it is mixed, it differs significantly from standard cement in the use of one ingredient. Rather than using Portland cement for a cementing agent in the mixture, refractory cement uses a compound called calcium aluminate instead. This provides the heat-resistant properties needed.

Refractory mortar is a specially engineered mixture of sand, calcium aluminate, cement, and fireclay. It is used to lay firebrick in places that are exposed to extremely high temperature. The refractory mortar is utilized only to build fire places and shall not be applied on hot faces.

Mortar, which is a mixture of water, cement, and sand, has a higher water-to cement ratio than concrete. It has a thicker consistency which makes it a great adhesive and bonding agent for bricks and tiles. Mortar mix can be used for construction and repair of brick, block, and stone for barbecues, pillars, walls, tuck-pointing mortar joints, and planters.

3. Refractory fire bricks

A fire brick is a block of refractory ceramic material used in lining furnaces, kilns, fireboxes, and fireplaces. A refractory brick is designed mainly to withstand high heat, but should also usually have a low thermal conductivity to save energy. Usually dense bricks are used in applications with extreme mechanical, chemical, or thermal stresses, such as the inside of a wood-fired kiln or a furnace, which is subject to abrasion from wood, fluxing from ash or slag, and high temperatures. Dense refractory bricks have a high thermal mass which is sometimes a useful property in that they will retain heat eg in a pizza oven after the fire has been taken out. Kiln bricks are made by firing a clay based composition in the kiln until it is partly vitrified, and for special purposes may also be glazed. Refractory bricks usually contain 30-40% alumina and the primary raw material is usually chamotte with other materials. The maximum service temperature increases with increasing alumina content and kiln bricks can be obtained with an alumina content of 80% and above.

Less dense refractory bricks (Insulating Fire Bricks)

In other, less harsh situations, such as a natural gas fired kiln, more porous bricks are a better choice, usually referred to as Insulation Bricks. They are weaker, but they are much lighter, easier to form, and insulate far better than dense bricks. In this case they have a low thermal mass and so cannot be used to store heat. Insulation bricks have a better thermal shock resistance than dense firebricks but the main disadvantage is their low strength. The insulation property of these bricks usually comes from perlite or vermiculite. As with the dense refractory bricks there is a range of grades corresponding to different maximum service temperatures. The most common is Grade 23 – 1260^oC.