A Study on the Amount of Free Silica in the Dusts of Stonecutting Factories and Offering Controlling Solutions
This research aims at determining amount of dispersion of free silica and inhalant dusts and contents of free silica in the inhalant aerosol of stonecutting factories and offering engineering control strategies to omit or decrease distribution of the aerosol containing silica. Using standard method Niosh- 7601, 40 samples of inhalant dusts were taken from 5 stonecutting factories and concentration of inhalant dusts was calculated by weighting. One sample of each stonecutting factory was analyzed by method of UV-VIS to figure out the amount of free silica. Two volume samples were provided and analyzed by X-ray dispersion to determine type of silica in the inhalant dusts. Concentration of inhalant dusts containing free silica in different worksites is 2.232 mg/m3 in average. The most amounts were found in grinding and polishing worksite amounted to 3.3293 with criteria deviation of 0.54 and the least amount was related to entrance door station, amounted to 1.1191 with criteria deviation of 0.25. The most amount of free silica in the worksites was related to worksite No.3, amounted to 12.15% and the least amount was related to worksite No.4 which was amounted to 4.25%. The most concentration of inhalant dusts was related to worksite No.2, i.e. 2.745 mg/m3 in average, and the least concentration of inhalant dusts was related to worksite No.5, i.e. 2.056 mg/m3 in average. Quartz was the result of analysis of volume samples by XRD method to determine type of silica.
