Topic 25: THE INDUSTRIAL MINERALS AND ROCKS

These are non-metals that have useful (and sometimes unique) properties that make them valuable for industrial use. Some are useful because they can operate at extreme physical conditions, such as high temperatures or pressures, or display great hardness. Others are useful because of their chemical makeup, enabling them to be converted into industrial chemicals (e.g., salt, borate, gypsum), fertilizers (phosphates, nitrates etc.), or explosives (nitrates). Others occur as rocks (mineral aggregates), whose bulk properties are appropriate for concrete or asphalt aggregates (crushed stone), or dimension (building) stone in the construction industry. The latter may involve cut or polished stone for interior or exterior use.

Some desirable (in some cases unusual) physical properties exhibited by minerals and rocks include:

1. hardness/softness (abrasives in cutting and polishing)

2. durability (chemical inertness, abrasion resistance)

3. thermal stability (insulation, fire resistance, low/high expansion)

4. electrical resistance (insulators)

5. density (light, or heavy)

6. optical (transparency/opacity, reflectivity)

7. aesthetic qualities (gemstone, facing stone, tile)

8. workability (flexibility/brittleness/ductility)

9. strength (strong, weak)

.

An alphabetical list of some important "industrial" minerals:

asbestos

beryllium minerals

boron minerals

clay (specialty; kaolin-rich, ceramics; smectite-rich, drill mud)

clay (ordinary; filler)

diatomite (filter beer)

feldspar (mostly K-spar)

fluorspar (fluorite)

gypsum, anhydrite (plaster, gypsum board)

limestone

lithium minerals

magnesite (MgCO3)

marble

mica (muscovite)

nepheline syenite

perlite (light aggregate)

phosphate minerals

potash (K) minerals

pumice (pumicite) (abrasive)

pyrophyllite

salt (halite)

sand and gravel (a trillion $ industry!)

sand (specialty sands)

shale (expandible)

shale (road metal)

sodium carbonate

stone (aggregate-crushed)

stone (dimension)

sulfur

talc and soapstone

vermiculite