PERLITE DEPOSITS FOUND

Press, Volume LXXXIX, Issue 27186, 2 November 1953, Page 13

PERLITE DEPOSITS FOUND

Valuable Insulating

Material

COMPANY FORMED FOR EXPLOITATION

(New Zealand Press Association) WELLINGTON. November 1. Large quantities of perlite have been discovered in New Zealand. The finds have been announced by the discoverer, who has formed a company to produce perlite for New Zealand use and possibly for export. Formerly, the main source of perlite, which has valuable insulating properties, has been in the United States.

Perlite in its natural form has been found in several places in New Zealand by Mr B. T. Giles, director of an electrical organisation in Wellington. One of his finds is an entire hill of rock within five miles of a railhead. All the material found is in waste country. Mr Giles was led into his search for perlite through a development in his electrical business. During World War 11. when he was serving as a commander in the Navy, he noticed that heat produced in radar cables when they were overloaded warmed the cabin. This turned his thoughts to radiant heating by electricity. After the war, Mr Giles imported cable for this form of heating, and found it satisfactory. What was not satisfactory was the loss of such heat through the walls, floors, and ceilings of the rooms heated. He then looked for a reasonably economic form of thermal insulation to use in conjunction with radiant heating, and concluded that perlite was the best insulating material. Even if dollars could be obtained to buy perlite, however, the cost of shipping it from America was 20 times the cost of the material.

4fter considerable investigation, Mr Giles found extensive deposits of perlite in New Zealand. Some of them are in an abandoned gold mine. The rock will be quarried and taken by rail to the main centres for processing. This consists of crushing and heating in a special retort. The rock dust is blown into this retort, exploded by the heat, and blown out as commercial perlite. The processed perlite can be used to replace sand and aggregate in concrete. and as it is only one-tenth the weight of these, it not only insulates, but also reduces the weight of the building.