GEOLOGICAL SURVEY OF IRAN | WWW.GSI.IR
 
فارسی  |     
Home |  Contact Us |  Help 
    Member Login
Username
Password
 
  Economic Geology
Perlite and Pumice
Title book : Perlite and Pumice
Author : Mansour Qorbani
Publisher date : February 2000
Chapter title : Chapter1 – generalities about perlite
Data title : 1-12-Perlite Artificial preparation and usages and perlite Use in Industry

Perlite is baked due to contain specific physical properties as primary material in refractory structure , agriculture , gardening , detergents stile and fillings , steel , environmental control , screen help and also mixed to gypsum or cement with much extent

From total of produced perlite , has various consumptions in the world as 70% mixed to gypsum, 15 % mixed to cement and 15%  of that is various .

 

1-12-1- Perlite mixed to gypsum or perlite pitches

As it is said more than 70% of produced perlite and it is mixed to gypsum that this idea is due to have many characterizations as pre-constructed by numerous companies that some of characteristics are such follow .

A- Weight of constructed blocks results in economical way in iron usage in structure.

Isolation capacity (k) in this mixture equal to 0.4 to 0.8, in comparison to gypsum and sand mixture that coefficient is 3 to 3.5.

C – It is stable against to stresses and it does not crack.

D- Against to fire, it is well stable.

It has refractory characteristics and it is conducted for thermal  

E- Absorption characteristics of sound absorption with high amount.

Perlite Pitch has following characteristics rather than gypsum or cement pitches:

- Its weight is half of usual plasters.

- Its stability is 4 times against to fire.

-Thermal in conductive characteristics is 4 times.

-Aquatic characteristics are very more than usual plasters.

These characteristics results in using a mixture from perlite to gypsum or as pre-constructed fragments in barrier walls and or its pitches to gypsum in thin layer on the surface and or between walls.

Although a concrete is constructed by perlite it is not strong as much as pumice and other materials but this mixture can be tolerated up to 2,000 tons some characteristics are such as low density, good barrier against to fire and it results in to perlite concrete and it is a good tool for construction of blade in metallic structures and veil coverage.

 

Kcal/mh°

 Electrical conductivity specific

perlite

 

23/0

94/0

1:1

 

16/0

70/0

6:2


Perlite and cement Concrete

Pre-constructed fragments are common by use of perlite and cement concrete in construction industry. These products are more than usual concretes due to following characterizations.

A- Its weight is less than half of cement.

B- Its stability is against to fire 4 against to usual cement concrete.

C- Its thermal conductance is 8 times less than usual cement concrete (8 times more barrier).

D- Its sound conductance is less than cement concrete.

More than these cases, it is due to tolerate and its installation in structure results in charge decrease and it is a factor for costs decrease and staff usages.

This mixture is treated in barrier wall structure, in low height structures and in main and veil wall, pre-constructed, temperature, barrier, veil coverage, roof, colorful pitches, sound isolation materials, preparation of light bricks and it is mixed to tar in especially cases as filter in water treatment and industrial and food liquids, physical amendment, preparation of light bricks in farming soil, plastic industry, reservoirs and hydrocarbon pipes.

In mentioned cases, perlite mixture to gypsum and cement (perlite concrete)with dimensions of 3mm In structural consumptions , some numerous rivals are present in perlite such as vermiculite , mineral wool in plastic values , asbestos  and other light mixture and perlite competitors in filtration means and treatment of materials : siliceous sand diatomite’s and   plant fibers .


2-12-1-filling for thermal barrier

Baked perlite can be filling in two walls structures and or two walls gas reservoirs, liquid oxygen, liquid nitrogen and it is used in production industries of oxygen ix fridges and other cases which needs thermal isolation.


3-12-1- Preparation of perlite pages

By mixing of perlite to a cohesive material such as gypsum and color full cement, we can prepare an ideal beautiful and suitable stable ones for coverage of chambers and saloons.

These plates have some light, beautiful, barrier characteristics against to sound temperature and they can not be installed easily.


4-12-1 – Preparation of thermal barrier products

Perlite has high thermal isolation characteristics and we can produce some cylinders that pipes passes among them. By mixing of perlite and Asbestos and impressing them, we can make these fragments.


5-12-1- Gardening Consumptions

By adding of baked perlite to gardening soil has suitability of gardening soil. Soils characteristics with perlite are:

A- This soil has water retention feature (water absorption is high in perlite). As we can add 10 liters of water to soil and they are near to 7.2 to 9.3 other than that, water evaporation is very little from this soil and water amount in soil , foods and pesticides are leached in soil by water and it has long time available plant rook so pesticides amount is decreased too .

B-Due to contain much porosity among perlite grains, soil is more than usual soil, more than that, presence of water percentage and air prevents from plant wilting point from depression.

C- Due to Isolation characteristics, a temperature which is given to soil perlite and depression phase and temperature inside of soil which is caused due to change environment and it likes soil freezing.

D – Root moves easily inside of this soil, so it uses foods in the soil.

E- Because of constant composition of perlite there is no much chemical changes in the soil and micro organism have an effects on this material for creation of residual materials.


6-12-1- Smooth material or smoothing help

Baked perlite and diatomite are used in much extent in filtration industries.

Some present pores in smoothing help results in passing and separating of filtrated materials rapidly inside of the cake. Filtration mechanism is done by perlite smoothing by mechanical method not chemical.

A screen material has following characteristics.

A –It has low weight

B- From chemical aspect, it can not be combined to filtrated material.

C-Smoothing material should be a cake with much porosity.

D- Total of grain surfaces. may be less or more and stability of liquid flow is due to viscosity force of liquid against to total of grain surfaces .So , if total of grain surface is less , liquid flows rapidly , inside of the cake and it passes .

E- Graded Bedding should have ideal form in smoothing material because if grains are very fine, total of grain surface is more and it prevents from accelerating pass of smoothing and if grains are very big, material will not be good smooth so we should determine best graded distribution and it is just because of type in smoothing material and smoothing helps are constructed by various degrees.



Related links