Industrial Sands are specialists in the production and supply of filter media products – distributed throughout NZ.
As a New Zealand standard does not exist for Filter sand, the USA standard AWWA B100 Filtering material is used as a basis in conjunction with NZS 3111 Methods of test for water and aggregate in concrete.
Filter sand is hard grained quartz or silica sand having no constituent & in any way friable or liable to mechanical breakdown when subject to pressure. The sand contains no carbonaceous matter, clay or silt and the loss on acid washing and ignition in each case is less than 2% by weight. The specific gravity is not less than 2.2 or more than 2.5 The filter sand is within the size range of 0.6mm to 2mm
The effective size is approximately 0.65mm. (Effective size is defined as the size such that 10% of sand grains are smaller & 90%larger).
The uniformity of coefficient is the ratio of the sieve size passing 60% to the sieve size passing 10% of the sand.
Typically sand is clean, immature sand, dominated by fresh transparent to translucent very light feldspar, but also containing dark pyroxene and other components.
Microscopic examination reveals subhedral and angular broken crystals of fresh plagioclase, fresh to slightly iron-stained pyroxene, fresh opaque oxides, unstrained quartz, fresh green hornblende and fresh to lightly iron-stained brown biotite. There are also cuspate shards of colourless isotropic fresh glass. Less commonly the same type of glass occurs as equant massive fragments or as porous pumiceous fragments. Minor other components comprise small lithic clasts of fresh to lightly weathered finely crystalline intermediate and acid volcanic rock.
The sand is typically regarded as clean, texturally and mineralogically immature sand, dominated by Piagiociase feldspar but also carrying other crystals, volcanic rock fragments and siliceous glass shards.
ISL’s Glass filter media is produced from 100% recycled glass (fused silicon dioxide)
which has been extensively washed and sterilized, prior to being ground and screened to the correct filtration media sizing.
Washed and sterilized glass media provides a high quality-filtering product, which delivers a safe & environmentally sustainable alternative.
Industry tests have shown that in some cases glass filter media can last up to three times longer than other filtration media, and allows for faster and cleaner backwashing.
This means potential savings on water & expensive chemicals due to the necessity of frequent backwashing.
Bacteria absorption within the filter unit is depressed due to the smooth surfaces of the glass media.
The following range of aggregates / pea metal are available. It is possible that othe sizes could be procured and screened... should a client require a certain size range.
Aggregates are presented in a dry state and are available in 25kg bags or bulk bags (by arrangement).