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November 17, 2008

Alysha Premji

Fatima Baessa

Kris Manipon

Lise Malta

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MineralsBorax, PVA PolymerMining

GlassBleach

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Boron

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Sassolite Kernite Tincalonite Ulexite

Sassolite B(OH)3

Kernite Na2O 2B2O3 4H2O

Tincalconite Na2O 2B2O3 5H2O

Ulexite Na2O 2CaO 5B2O3 16H2O

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Complex borate mineral made of chains ofBO2(OH) triangles and BO3(OH) tetrahedrons

and bonded to sodium and water.

Formula: Na2B4O7 nH2O (n=5 or 10)

Borax

MOST SIGNIFICANT BORATE MINERAL DUE TO

ITS MANY INDUSTRIAL USES!

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Reaction: Borax and Polyvinyl Alcohol produces PVA Polymer

Uses: Bag containers for pre-measured laundry soap, bags for

cotton cloth or bed linen of infected hospital patients

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Where on Earth are you most likely to find borates?

Step 1) Travel to the site of a dried up lake

Step 2) Dig 150-300 feet below the surface

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Industrial Mining ProcessDrilling

Explosions

Removal of Rock,Transport to

Crusher

Dissolving ofMinerals in H2O

InsolubleRocks

CrystallizerBorate

Minerals

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14th Century Boratesbegin to be used in

glassmaking process

8th Century Gold andSilversmiths use borates in

refining

10th Century Borates areused in Ceramics

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Significant

BorateDeposits in

the

Americas,

Europe,

and

Turkey

Discoveries of Borate Deposits (19th Century) Leads to

the Development of the Borate Industry

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Industrial Application: GlassSilica

Soda (Na2O)Boric Acid ( B(OH)3 )

Borax Pentahydrate

Dehydration

2 B(OH)3 3 H2O + B2O3

boric acid water + boric oxide

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Trigonal Planar BO3

Tetrahedral BO4

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Adding B2O3to Glass

B

O

O

O B

OO

O O

Na+

O2-

Na+

Na+

+ 2 2

Non-bridging oxygens

Trigonal Planar

Bridging Oxygens

Tetrahedral

More stable and rigid glass

2

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The key ingredient in Boratebleaches is sodium perborate

Use of Borates

in Bleaches toForm a Cleaning

Agent Through a series of mechanisms,Hydrogen Peroxide is formed, which actsas a bleaching agent

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B

O O

B

OOH

OH

OH

OH

OO

B

O O BO

OH

OHOH

OH

OHH

BOH O O

B

OHOH

OOH OH

OH

BOH O

OH OH

OB

OHOH

O OHO B

O

OHOH

OH

OH BOH

O

OH

O

HH

OH B

O

OHOH

OH

OH B

OH

O

OH

O

H

OH B

O

OHOH

OH

step 1 step 2

step 3

step 4+step 5

+

step 6

2

Mechanisms to Produce Hydrogen Peroxide

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OH BO

OHOH

OH

OHH

B

OH

OHOH

O

OHH

O

H

BOHOH

OH OH

H O O H OOH H+H OB

OH

OHOH

step 1+

step 2

+ ++

Mechanism Continued

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Stains or colour in materials containconjugated double bonds

Bleach acts as an oxidizing agent

Peroxides break the double bonds toremove the colour

How Does

Bleach Clean?

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MineralsBorax, PVA PolymerMining

GlassBleach