TECHNOGENIC HAZARDS COEFFICIENT OF SAND-RESIN MIXTURES IN FOUNDRY MANUFACTURING

Abstract

Purpose. To carry out a comparative quantitative assessment of environmental and sanitary-hygienic hazards of utilizing synthetic resins for manufacturing molds and rods in foundry production. Methodology. Quarry quartz sand brand 1K2O202, furan resin brand Permaset 839 and catalyst Permacat 128, aluminum alloy AL2, gray cast iron SCh200, carbon steel 30L, bronze BrА9Zh3L were used in the work. Chromel-alumel thermocouples completed with electronic potentiometer were used for thermography. Molds were made from quartz sand, furan resin and catalyst mixture. Casting mold heating depth determination from casting to temperatures above 400 °C was carried out by its thermogram graphical processing, which was obtained after casting mold pouring with aluminum alloy, bronze, gray cast iron and carbon steel. Findings. Among those studied, the most dangerous are urea-phenol-formaldehyde, urea-formaldehyde and urea-furan resins, and the least dangerous are phenol-formaldehyde and phenol-formaldehyde-furan resins. Ecological and sanitary-hygienic hazard level when using resin mixtures increases with increasing resin amount in mixture, castings walls thickness, their surface area, as well as with increasing temperature of melt poured into the mold. Originality. For the first time, in relation to foundry molds and rods in foundry production manufacturing, technogenic hazard coefficient (THC) has been developed and its value has been calculated. This, in fact, is air volume (m3 ) containing maximum permissible concentration of carcinogenic or poisonous substances released as a result of mold organic binder material destruction when pouring aluminum alloy, bronze, cast iron or steel. Practical value. The use of the research results makes it possible to increase the level of predicting accuracy of technogenic (sanitary, hygienic and environmental) hazards, accuracy level of calculating ventilation systems capacities in foundries, taking into account the serial castings production, castings structural features, as well as binding materials nature for foundry molds and rods for such castings.