Pumice
Composition
PUMICE – NATURALLY EXPANDED ALVEOLAR MAGMATIC MINERAL
Pumice is the result of the natural expansion of effusive magmatic mineral that has generated an alveolar product of remarkable lightness, with high porosity, great water retention, slow release of liquids and high thermal and acoustic insulating properties.
Being a natural volcanic inert, it is absolutely ecological, and therefore, is recommended and suitable for nursery gardening applications where it is already widely used. Pumice is also highly appreciated in the building and construction sector for its high hygroscopic and pozzolanic characteristics.
PUMICES AND LAPILLI ARE PRODUCTS OF EXPLOSIVE VOLCANIC ERUPTIONS
PUMICES and LAPILLI are products of explosive volcanic eruptions formed following a violent expansion of the gases dissolved in lavas with an acid chemical composition. The rapid cooling of the rock has prevented the crystallization of the same, trapping internally the gases and generating more or less expanded beehive minerals. During the solidification, the vapours present in the magma, suddenly released, have caused the swelling of the whole magma mass. During this phase of rapid cooling, certain differences in the physical structure of various inert volcanic materials have been released.
The magma, which has originated the PUMICE, had such a chemical composition which permitted the rapid expansion of gases dissolved internally, forming a kind of foam. The rapid cooling of the lava has determined an unexpected solidification of the liquid part around the gas bubbles generating this appearance of vitreous foam of the pumice. The internal part of the rock is in fact composed of an enormous quantity of ducts having a very small/medium diameter, intercommunicating between themselves and also externally.
Fields of application
Nursery gardening
Substrate for roots - Preparing composts – Mulching – Hydroponics – Off-ground crops – Soil conditioning –Hydroculture – Drainage.
Building Industry
Lightweight, thermo-insulating and soundproofing screeds – Sound-absorbing barriers – Substrate insulation – Road embankments – Flues and chimney – Lightweight panels – Thermal insulation – Lightweight fillings - Green building - Pumice for masonry mortar and plaster (Pumice Sand)
Others
Stone Wash for fabric treatment - Filtration - Dentistry - Abrasives - Sandblasting
Filling with Pumice – Hydroponics
Slight filling with Pumice – Terme Traiano, ROMA
Pumice Sand – Soccer Stadium San Paolo, Napoli
Physico-chemical Characteristics
Nursery gardening*
pH 7-8; Cation Exchange Capacity (C.E.C.): approx 30 mEq/100g
Building Industry
Thermal conductivity λ between 0.0872 and 0.1021 W/(mK), high acoustic and thermal insulation, transpiration, workability, fire-resistant, durability
Liquid absorption**
for 100 g of dried Pumice:
Water: approx. 100 g
Lubricating oil: 110 g
Diesel fuel and Gasoline: 80 g
Mineral containing no active limestone and no Free Crystalline Silica (non-toxic product)
Imperial Measurements
* Liquid absorption: approx. 0.13-0.15 lb. of water / 0.22 lb. of pumice (at quarry humidity)
C.E.C.: approx. 30 mEq/0.22 lb.
** Liquid absorption: for 0.22 lb. of dried pumice: Water approx. 0.22 lb. – Lubricant oil 0.24 lb. – Diesel fuel and Gasoline 0.18 lb.