Raw perlite grades:

Raw perlite grades suitable for expansion are produced from the perlite rock by crushing, drying and sizing. The water content trapped in the structure of the raw perlite varies between 2 and 5%.

Chemical analysis:

Chemical composition:

In the preparation plant in Pálháza following grades are produced at present:

Following properties of the material mined and prepared in milling plant are regularly controlled:

Expansion rate:  0,1-0,3 mm grains are expanded in a lab-kiln. The loose apparent density of the expanded material should not exceed 35 g/l.

Dead rock content:dead rock content of the perlite is tested by watery separation, the dead rock content should not exceed 5%.

Surface moisture:perlite sample dried until weight consistency at 105° C. The moisture content measured of sample has to be below 1%.

Sieve analysis

Compression strength: single-axle strength of the perlite expanded in a lab-kiln is measured by compaction rates of 20 and 40% in accordance with the Brook-method.

Grain structure of expanded material: tested by means of 0,5 mm sieve

Bound water content

Modern sieving equipment