Transcript Mii Photos Halite

COMMODITY SALT
What are salts?
WHAT ARE SALTS?
 Formal name for NaCl is Halite
 Chemically defined as reaction between Na, Cl and H2O to form NaCl or
compound of metal and non metal
 Greek word ‘hals’ means salt
Salt – crystalline compound NaCl.
 Salt-halite – colourless to yellow, but may be light blue, light blue and pink
 Pure NaCl contains by weight 39.34% Na and 60.66% Cl
 NaCl sometimes known as common salt or table salt
 Salt was used as currency to soldiers in the Roman society
PROPERTIES OF SALT
 Colourless to white but sometimes red, blue and
purple
 Exhibit isometric
 Refractive index of 1.554
 Hardness of 2
 Cell contents is Na4Cl4
 Perfect cleavage
 Specific gravity of 2.168
 Melting point of 804 degrees Celsius(1,479F)
 Boiling point of 1,413 degrees Celsius(2,575F)
MINERAL PHOTOS - SALT
Mii Photos
Halite (Sodium chloride--Salt)
GEOLOGIC DESCRIPTION - SALT
 Deposits are either in solution or in solid state
 Bedded Salt Deposit: Deposit is associated with sedimentary
rocks such as limestone, shale, dolomite and anhydrite.
 Salt Domes: formed as a results of deposition of restricted marine
basins, over period of time salt is then covered with sediment and
becomes buried.
 Lakes: Formed as a results of natural accumulations of water in
topographic depression.
 Groundwater: Formed either by connate or meteoric water.
Examples are chloride-sulphate, chloride-carbonate, sulphatecarbonate and acids.
 Solid Salt: They are found in playa lake deposits, bedded salt
deposit and salt domes.
MINING - SALT
 Rock salt is mined using room-and-pillar method of UG
mining.
- U.S and Canadian rock salt mine used this method.
 Salt can be produced by controlled evaporation of seawater or
brines in salt lakes.
-This process is used at Great Salt lake in Utah- U.S
 Vacuum pan process, this uses mechanical evaporation technology
- Salt is obtained by dehydrating brines using heat or in combination
with a vacuum.
 Salt is produced in most countries on earth.
PRODUCTION - SALT
 Oceans – 42% of salt is dissolved in oceans
 U.S - produces about 1/5 of the world’s salt
 U.S - also import about 1/5 of her salt from other countries.
 In U.S. 40% of salt is used in chemical industry and another
40% as a de-icer on roads during winter
 U.S. table salt account for only 1%
PRODUCTION - SALT Cont.
PRODUCTION - SALT Cont.
Source:
USES - SALT
There are numerous uses of salts in the world, the
following includes some of the uses.
 Food seasoning and food preservation
 Canning process- use as flavour enhancer and
preservative
 Baking- use in baking industry to control rate of
fermentation in bread dough
 Preparation of sodium hydroxide, soda ash,
caustic soda, chlorine, hydrochloric acids.
USES - SALT cont.
In oil and gas exploration- drilling fluids
Textiles and Dyeing- as brine to separate
organic contaminants
Use in the manufacture of neoprene rubber,
white rubber and other plastics.
High way de-icing- use to melt snow and ice
on roadways
FORMULA- Other uses
Name of salt
Formula
ammonium
chloride
NH4Cl
sodium
bicarbonate
Uses
in soldering, as electrolyte in dry cells
NaHCO3 in baking powder, in manufacture of glass
sodium chloride
NaCl
for seasoning and preserving food, essential in life
processes
calcium chloride
CaCl2
as a drying agent to absorb moisture, in freezing
mixtures
silver bromide
AgBr
in making photographic film
potassium
nitrate
KNO3
in manufacture of explosives; fertilizer
sodium nitrate
NaNO3
fertilizer; source of nitric acid
SUBSTITUTES - SALT
 No economic substitutes for salt
 Calcium chloride and calcium magnesium acetate,
hydrochloric acid and potassium chloride can be
substituted for salt but at higher cost.
REFERENCES - SALT
• 1. Barker, J.M., Kogel, J.E., Trivedi, N.C., and
Krukowski, S.T., 2006, Industrial minerals and rocks,
7th Edition.
• 2. www.saltinstitute.org/images/map.pdf
• 3. USGS, Minerals Commodity Summaries, January
2011
• 4. USGS, Minerals Yearbook - 2009