Measurements of recycling steel slug at Qatar steel using lowlevel gammaray spectrometry and calculation of risk factors

Abstract

Measurements of recycling steel slug at Qatar steel using low-level gamma-ray spectrometry and calculation of risk factors. M.S.Al-Kuwari 1, M. Hushari 2 and K E Hassan3 1Environmental and Municipal Studies Institute, Director 2Radiation and chemical protection department Ministry of environment, Doha-Qatar 3Transport Limited company TRL Correspondent author: Mohammad Hushari, P.O.Box7634 , Doha-Qatar. Tel w :(+974)44139476 Fax (+974)44207000 Mob :(+974)77991059 Email: mmhushari@mme.gov.qa. Abstract Steel slug are final by-products in the steelmaking process pose an environmental hazard for worker near slag dumps. The objectives of the study were the employment of high-resolution low-level gamma-ray spectrometry. The measurements of natural occurring radioactive material (NORM) as well as of the artificial isotope 137Cs, in many types steel slug such as Steel Slag loss aggregate, Asphalt Mix (100% steel slag with 4% Bitumen), slag, 50% Gabbro with 4% Bitumen, and Concrete cube (50% steel slag, 50% gabbro have been done using mentioned γ spectroscopy. The value of NORM material was reduced when they mixed with gabbro. The recycling of slag from the steel production industry is a common practice in all over the world. Slag from integrated steel production plants run by Qatar Steel is processed storage in area not far from the factory. It has therefore been assumed in this study that all slag is storage. Different ratio of steel slag, gabbro and asphalt used in road construction, most of this ratio accepted from radiation risk point of view, but the ratio of 50% of Gabbro and 4% of Bitumen with asphalt used as road base was the most acceptable from regulatory body. Construction of 200 m road was done at Mesaieed city at Qatar its mechanical and strain stress measurements was conducted by specialist in civil engineering, then many core sample from the surface to the bottom of road to measure (NORM) radioactivity have been taken and radiation dose at the site were carried out. The measured activity and hazards indices in asphalt mixing with slag lies within the word permissible values. Thus the used of recycling steel slug can replace at least 50% aggregates in highway construction and concrete