1.The corundum brick Production Process
Crushing→Mixing→Shaping→Drying→Firing→Inspection→Packaging and
Shipment
Raw material handling When fused brown corundum or white corundum is used as raw
material, the frit should be crushed and selected to remove the
ferrosilicon alloy or other impurities contained in the brown
corundum block. The white corundum block should be removed from the
flaky crystalline sodium peraluminate and other low-melting
substances. These impurity minerals usually float on the surface of
the corundum frit due to their low density and are easier to
identify. Corundum contains a small amount of harmful components,
which will cause poor sintering or cracking of the product, so it
should be calcined before use. The unsorted ferrosilicon alloy is
oxidized and decomposed into Fe2O3 and SiO2 at 500-1000 degrees,
and titanium-containing minerals are oxidized to TiO2 (rutile),
etc., all of which produce large volume expansion. After
pre-burning, these decomposition and oxidation reactions are
carried out. The damage stress is eliminated in the pre-firing
process to avoid the product cracking due to the expansion of the
reaction of these impurity minerals during the firing of the
product.
Crushing The fused corundum block is relatively large, so it needs to be
crushed with a falling hammer or other methods, then crushed, and
stored according to different particle sizes. Fused corundum has
high hardness and is difficult to finely grind. Therefore, ball
mill or vibrating ball mill should be used for wet grinding to
reach <40um or finer <10um. Electromagnet is used to remove
iron for granular materials, and pickling for fine grinding
materials. Ingredients, mixing and molding The particle matching
should be based on the principle of close packing, using
multi-level proportioning to reduce intermediate particles and
increase the amount of fine powder (containing a certain amount of
ultrafine powder), which is beneficial to increase the density and
sintering of the product. Add a certain amount of binding agent,
mainly aluminum phosphate, phosphoric acid, aluminum chromium
phosphate, cellulose, pulp waste liquid and so on. Among them, the
most promising is active phosphate. In recent years, ammonium
phosphate has been tried and achieved good results. The mud should
be mixed evenly and the moisture content is about 3%-4%. After high
pressure forming, compact bricks are obtained.
Firing
Fused corundum products have high purity and are difficult to
sinter, and need to be fired at a temperature higher than 1800
degrees. The firing kiln depends on the scale of production. For
small batch production, high temperature intermittent kilns are
suitable, and small high temperature tunnel kilns can be used for
stable batch production.
2.The corundum brick Quality Assurance
HongTai Refractory is committed to high quality standards for all
its products and services. With its thirst on State of the art
technology at every level and a wide range of products, HongTai
Refractory can provide ideal solutions for the stringent
requirement of the customer. Backed by decade of experience in
different industries, and close association with customers,HongTai
Refractory will always bring new products which will give better
life and value to the user.
The quality assurance system consists of the following steps:
1. Inspection and Control of incoming raw materials:According to
the chemical content,raw materials are classified into different
levels to ensure quality of brick first.
2. Inspection and process control:During the production, each brick
weight twice to reduce weight error.
3. Inspection of product Standardization of quality of each product
by process control and experimentation.
4. Taking corrective measures whenever deviations are noted.
