Thermal insulation composite with the use of mining waste

Abstract

The authors offer the use of environmentally friendly waste of mining plants located in the Arkhangelsk region as a binder to create a thermal insulation construction composite based on basalt fibers. This waste is the saponite-containing material (SCM) recovered from recycle water suspension produced during the enrichment of kimberlite ores from the diamond deposit named after M V Lomonosov (Arkhangelsk region). The SCM has binding properties and they depend on its dimensional characteristics and reach optimum values at an average particle size within 1-2 µm. The test samples of composites obtained at 105 0C with the SCM content varying in the range from 7.5% to 25% and the test samples of composites obtained as a result of thermal modification at up to 1200 0C with the SCM content varying in the range from 15 to 25%, were made under laboratory conditions. The raw mix for thermal insulation composite production contained the SCM as a binder with an average particle size of 1-2 µm, and basalt fibers with an average diameter of 3-6 µm as fibrous filler. Thermal modification of samples was carried out at a temperature up to 1200 0C according to the temperature-time mode used in expanded clay production. As a result of tests, it was found that the composite thermal insulation capacity decreases and compressive strength increases with an increase in the SCM content. Additionally it was noted that thermal modification of thermal insulation composites considerably increases their compressive strength without any impact on the heat transfer coefficient. Thus, it is possible to obtain materials with the specified performance such as the heat transfer coefficient and compressive strength by regulating a percentage ratio of components of the thermal insulation composite based on basalt fibers – the saponite-containing material. Additionally, thermal modification of the studied composite makes it possible to increase considerably compressive strength without changing its heat transfer coefficient. The obtained thermal insulation construction composite is environmentally safe and can withstand high temperatures without breakdown. The SCM will promote the effective solution of environmental problems associated with the development of the diamond deposit named after M V Lomonosov.