Unified assessment technique for magnesium production waste to be applied in construction

Abstract

Abstract. The article focuses on the possibility of the raw material base expansion for the magnesia oxychloride cement and construction materials due to the use of mining and mineral processing wastes. For this purpose, the assessment method of such wastes suitability as raw materials is developed. The methodological scheme of the magnesia oxychloride cement production is offered. According to the offered method the assessment of the magnesite from waste pit bingof «Group Magnezit» was conducted. Using the X-ray phase and thermal analysis of mineralogical structure, impurity distribution features are established depending on grain composition. The technology of combined roasting with the use of intensifiers is offered herein. This technology excludes presence of potentially harmful impurity in cement, in particular calcium oxide.

Investigation of magnesium oxychloride cement at the initial hardening stage

“…By overburn are meant magnesium oxide crystals enlarged up to the size of 50 nm. Even small amount of overburn containing in the powder causes internal expansion deformations in hardened magnesium paste as a result of their hydration accompanied by increase of volume by 2.5 times at later hardening stages [14].…”

“…In case of using the waste of fire protection or mining industries as raw material for cement production, one of the reasons for such deformations in hardened magnesium cement is high content of calcium carbonate in the source rock [15]. According to GOST 1216-87, the calcium oxide admixture which is synthesized while decomposition of dolomite and calcite is considered adverse for magnesium cement and shall be limited up to 5% [16].…”

Resistance of Caustic Magnesite Based Materials to Influence of Mold Fungi

“…Магнезиальный цемент, также называемый в честь своего открывателя «цемент Сореля», является незаслуженно забытым вариантом традиционного вяжущего. Но благодаря ряду существенных преимуществ, интерес к данному строительному материалу вновь и вновь заставляет как отечественных, так и зарубежных исследователей возвращаться к изучению его свойств и выявлению новых путей его использования в строительной отрасли [2][3][4][5][6]. Благодаря этому доля магнезиальных вяжущих и материалов на их основе в общем объеме применяемых минеральных вяжущих ежегодно увеличивается.…”