Phosphate rock is formed in oceans in the form of calcium phosphate, called phosphorite. It is deposited in extensive layers that cover thousands of square miles. Originally, the element phosphorus is dissolved from rocks.
Some of this phosphorus goes into the soil where plants absorb it; some is carried by streams to the oceans.
In the oceans the phosphorus is precipitated by organisms and sometimes by chemical reaction. Phosphorus-rich sediments alternate with other sediments . Phosphorus-rich beds usually have very few fossils; however, deposits in Florida and North Carolina contain a large amount of marine fossils.
Uses :
Some phosphate rock is processed to recover elemental phosphorus. Pure phosphorus is used to make chemicals for use in industry.The most important use of phosphate rock, though, is in the production of phosphate fertilizers for agriculture. Some is used to make calcium phosphate nutritional supplements for animals.
Industrial sand is a term normally applied to high purity silica sand products with closely controlled sizing. It is a more precise product than common concrete and asphalt gravels. Silica is the name given to a group of minerals composed solely of silicon and oxygen, the two most abundant elements in the earth’s crust.
In spite of its simple chemical formula, SiO2, silica exists in many different shapes and crystalline structures. Found most commonly in the crystalline state, it also occurs in an amorphous form resulting from Weathering or plankton fossilization.
Chemical Analysis
Over size 0.600mm 0.5 %
Under size 0.100mm 0.5 %
Quartz is a very common mineral, a chemical compound of silicon and oxygen, silicon dioxide SiO2, commonly called silica.Colored quartz varieties have been used for jewelry for ages, but most quartz is used as a component of concrete: quartz sand and quartz gravel.
Uses :
Pure quartz is needed for producing glass, ceramics, and chemical apparatus. Quartz glass, also known as "fused quartz" or "fused silica" (produced by quickly cooling molten quartz) has a number of interesting properties: its thermal expansion coefficient is very low, it is transparent for ultraviolet light, it is chemically almost inert, and it can form very thin but strong threads used in physical instruments.
A well known application of quartz is its use as an oscillator in electric circuits in watches and computers. Less well known is, for example, its use as a membrane in ultrasonic devices.
