Allied Mineral Products won this year’s Corporate Technical Achievement Award for its successful development of a unique graphitic refractory castable, STACKCRETE® G, commercially used in blast furnaces.
Carbonaceous bricks are heavily used in blast furnaces to allow passage of heat where conductive cooling is required. This passage of heat allows a protective skull to form on the surface of the working lining which helps contain molten iron and slag.
The downside to using bricks is that manufacturing and installing them can be a very tedious process. Manufacturing bricks first requires a pre-forming process, second a heat treatment process and third a milling and sizing process. Many bricks must also be cut and sized onsite to properly fit the furnace structure and meet specific design tolerances. This process adds to installation time and labor costs.
Due to the disadvantages of the carbonaceous bricks, Allied’s research and technical team developed a graphitic based refractory that is water dispersible. A water dispersible resin is utilized for the curing and hardening of the refractory and also increases the hydrophilic properties of the refractory. This material does not use alcohol-based solvents, which are common in monolithic graphitic systems. Thus, there is reduced environmental impact and user friendliness with this material.
Since this product will be used to replace brick or repair brick, it must exhibit similar properties to the carbonaceous brick. This material does just that by having high thermal conductivity, volume stability and strength as well as thermal shock, alkali and abrasion resistance. The initial material, now known as STACKCRETE G, was first successfully installed in a 2010 trial. Since, then, installations using a high volume placement method known as shotcreting, both manually and robotically, have been applied in the bosh of a number of blast furnaces in North America, South Africa and Brazil.
STACKCRETE G can be cast, pumped, shotcreted or gunned and can be used to repair existing carbonaceous bricks or as replacement lining for the brick. The installation time for the shotcreted method is phenomenal as 5 tons per hour of material can be applied.
Allied’s innovative product is until now, the first commercial graphite based monolithic refractory that is capable of being mixed with water, easy to install, pumpable over several stories high, bonds to old carbon linings and has very good physical properties and chemical attack resistance compared to traditional small carbon brick design.
Improvements to the original technology are ongoing to increase thermal conductivity and optimize physical properties for applications outside of blast furnace operations, such as cupolas, submerged arc furnaces and other operations which require repair of graphite brick.
About Allied Mineral Products:
For over 50 years Allied Mineral Products has engineered, manufactured and shipped monolithic refractories and precast shapes. Allied has a strong presence in the foundry, aluminum, steel, cement, lime and mineral processing markets and boasts an extensive line of products. Allied has 8 manufacturing facilities worldwide, a global sales and technical team and 2 research and technology facilities with extensive testing capabilities.
Allied’s pride is in its technical capabilities. Allied can install, analyze and trouble-shoot product installations anywhere in the world.
The Allied advantage as a global manufacturer is its ability to be there and provide technical solutions. Allied has distributors all over the world and can ship from the US as well as China, India, Europe, South Africa and Brazil.