Expanded Clay

Expanded clay is a brown lightweight aggregate with a nominal particle size of from 8mm to 12mm. The material complies to BS 3797 Part 2 1990 (including all appropriate European standards for lightweight aggregates. Expanded clay is non-toxic, disease free, resistant to algae, chemically inert and sterile with a neutral pH. It has good insulating properties over a wide range of temperatures, will not compact and is unaffected by frost. 

Source and Manufacture	Expanded clay is manufactured from naturally ocurring clay. This is quarried and then sent to a rotary kiln where it is expanded at a temperature of 1150oC. The moisture trapped in the clay is forced to turn to steam creating countless tiny air bubbles surrounded by a hardened shell. It is these sealed pockets which account for the light weight of expanded clay.
Chemical Properties	Typical composition of this material is: Silicon (SiO2) 60.6% Aluminium (Al2O3) 18.3% Ferric oxide (Fe2O3) 8.54% Magnesium (MgO) 3.83% Potassium (K2O) 3.56% Lime (CaO) 2.18% Titanium (TiO2) 1.07% Sodium (Na2O) 0.48% Phosphorus pentoxide (P2O5) 0.18% Others 0.20%
Physical Properties	The bulk density of expanded clay varies by grade from 300 to 600 kg/m3. The approximate thermal conductivity of the loose dry material is 0.113 w/mk. The co-efficient of thermal expansion is 6.8 x 10.6oC Permeability in normal conditions is approximately 20% by weight and 100% relative humidity would be 40% by weight. The dry shrinkage in a 1 part of OPC to 6 parts of medium grade expanded clay is 0.05%. The aggregate is unaffected by frost, can withstand termperatures of up to 1000oC and is non-combustible. Specific gravity is 10mm 0.55. Specific heat is approximately 1.25 - 1.35 Kj/kgK. The pH value is approximatey 7.
Grades	Standard grades available are: Optiroc Standard Grade 4 - 8 mm   Medium Grade 4 - 10 mm   Coarse Grade 10 - 20 mm   Maxit LWA Insufill 10 - 20 mm       Arlita Fine Grade 1 - 4 mm   Standard Grade 3 - 8 mm   Large Grade 8 - 12 mm
Prices and Conditions of Sale	Prices are quoted on a volumetric basis, ex works plus haulage. All quotations give, orders placed. and materials supplied are subject to our Standard Conditions of Tradeng, a copy of which is available on request.
Packaging	Expanded clay is normally supplied in 50 litre heavy duty plastic sacks and palletised. The Optiroc pallet holds 21 x 50L packs. The Arlita pallet holds 65 x 50L packs. Optroc grades are also available in 1250 litre bulk bags of bulk.
Supply	Expanded clay can be collected from our production unit at Gainsborough or delivered direct anywhere in the UK. Free trial bags can be sent to any company in the UK in response to a written request indicating the type of application and potential usage if satisfactory. Technical information is also available for many applications and advice can be given on alternative bonding systems to make rigid shapes, etc.
Health and Safety	Click to download a copy of the Material Safety Data Sheet.