The use of waterjet cutting wastes in the production of building materials

Abstract

Investigation and involvement in the production of new, earlier not used manufacturing waste and consumption is the current task directly associated with preservation of natural resources and protection of biosphere from pollution. To such waste, we refer dispersed waste of metalworking formed while cutting of metals, operation of crushing machines, etc. The purpose of this work is to study the composition and properties of waste from hydro-abrasion (waterjet) cutting of metals and estimation of their use in the production of building materials. They are related to V class of hazard the conditions of their formation are such that no new compounds arise complicating their possible application. The essence of the process of waterjet cutting, mechanism of waste formation, substance composition and volumes of waste accumulation at the enterprises, current situation in the sphere of their utilization is described. The composition and properties of the abrasive applied – garnet sand composed mainly of ferrous-aluminium garnet – almandite – one of the most hard and durable of known useful minerals. A complex investigation of waste from waterjet cutting was carried out: the average and bulk density, granulometric composition, chemical composition were determined, the electron microscopic study of various waste fractions was performed. It was found that in the process of cutting, the destruction of abrasive particles occurs, the size and shape of granules changes as well as the nature of their surface, a large amount of dust fraction appears, where particles of cut metal fall. At the same time, in the process of sand particles destruction, new abrasive faces arise, and their recycling is possible. It was established that waste of waterjet cutting of metals present very small, practically uniform heavy sands with high content of dust fraction, in the chemical composition of which prevail ferric oxides, silicon and aluminium oxides. Such characteristic of waste allowed mark possible ways of their application: 1) in the production of pottery work as inert additives and flux-additives, 2) in the production of Portland cement as corrective iron-containing additive and component of raw mix for high ferriferous cements; 3) as a filling agent in mortars, including special mortars, 4) as a pigment for voluminous painting of building materials, etc. Positive results have been obtained on the use of waste from waterjet cutting in the production of ceramics. A raw mix consisted by 50% (by mass) of montmorillonite clay and by 50% of waste from waterjet cutting of steel. After burning at 900° C, physical mechanical properties of samples have been determined. The results obtained permitted to make the conclusion about the possibility of using these waste as the poly-functional additive in the manufacture of ceramics.