New To The Mineral Processing Trade? Learn Why Ceramic Is The Material Of Choice For Mineral Processing Equipment
If you're new to the mineral processing industry, chances are you are considering your equipment purchase options. Ceramic is one material that is often used in the industry's heavy duty machinery. Learn how this versatile material earned its reputation for durability and strength in outer space, and how it's used in terrestrial applications.
Ceramics and the Space Shuttle
NASA unofficially labeled ceramic a super hero. Ceramic tiles, roughly the size found in your bathroom or kitchen, were plastered on the belly of the Space Shuttle. Able to withstand temperatures up to 2,300 degrees Fahrenheit, these ceramic squares brought the orbiter back to Earth safely time after time.
One exception was the Columbia that fell apart on re-entry in 2003. That tragedy was attributed to debris hitting the wing and knocking some tiles off, rather than tile failure. In true NASA fashion, engineers came up with a plan for the astronauts to check and repair missing or loose tiles while still in orbit. The mixture they used was a combination of silicon carbide fibers, already incorporated into the ceramic tiles, mixed in the same type of black glue that was used to attach the tiles.
Black tiles were used on the lower part of the shuttle because they reflected 90 percent of the re-entry heat back into space. Tiles on the top were coated with silica and aluminum oxide; their white faces had a temperature threshold of up to 1,200 degrees Fahrenheit.
Ceramics for Terrestrial Use
If ceramic is durable enough to withstand the extreme temperature variations and pressures of space travel, it's not surprising that this material has so many uses on planet Earth. Ceramics have been proven invaluable in the mineral processing field. Some of the ways ceramics are used in that industry are listed below.
Ceramic Ball Bearings
As evidenced, ceramic is heat resistant. It is also harder than steel, which makes this material ideal for ball bearings. Ceramic ball bearings can last three times longer than the steel variety. They don't deform as easily, roll faster and can be used in wet environments without the worry of rust. They also act as electrical insulators, a plus if you are working with a material that is flammable.
Ceramic Brick For Ore Ovens
That heat resistant quality comes in handy when ceramic is used as a lining for industrial brick ovens. These types of ovens are used in processing ores in coal-fired power plants, steel mills and asphalt plants. This type of mineral processing can produce an immediate end result, such as electricity from coal. Or, it can produce a product that can be turned into something else, such as the molten liquid that is used to create steel. The ceramic bricks are glued on with special industrial adhesives.
Ceramic Grinding Media
Many types of minerals must be ground down to be used in various applications. Silica sand, for example, is made of certain varieties of quartz. While some of this sand is eroded by nature, quartz crystals are also mined and ground into sand. Silica is one of the key ingredients in making glass.
The quartz is usually crushed in a grinder that has two cones. The upper one rotates while the lower one remains still. The quartz is funneled in between the two cones and crushed to a specified size. The crushed sand falls out the bottom.
Quartz rates a seven on the Mohs Hardness Scale. That's three below a diamond's rating of 10. Crushing or grinding quartz produces friction which in turn creates heat.. By coating the outside of the moving cone and inside of the stable cone with a ceramic material, it reduces the heat buildup from the friction.
For more information on using ceramic in mineral processing equipment, check out a company like Ceramic Technology Inc.