Epoxy Flooring/Oil Fly Ash as a Multifunctional Composite with Enhanced Mechanical Performance for Neutron Shielding and Chemical-Resistance Applications.

Heavy-oil fly ash (HOFA) is a graphitic carbon powder extracted in vast amounts as a waste material from burning crude oil in power plants. This HOFA has attractive structural properties besides its high amount of pure carbon (∼90 wt %). This powder exists in spherical, highly porous micron-sized particles, which implies its great potential as a mechanical reinforcement for different polymers. In this work, HOFA has been utilized to enhance the mechanical properties of epoxy flooring at HOFA weight fractions of 0, 1, 1.6, and 3.2 wt %. The obtained results revealed that the prepared epoxy-flooring/HOFA composites at a HOFA content of 1.6 wt % showed significant mechanical improvements compared with the pristine polymer. The tensile strength and Young's module values were enhanced by ∼17 and 11%, respectively. Furthermore, the neutron-shielding performance was investigated. The composite with 1.6 wt % showed better neutron attenuation and lower transmittance than the pristine epoxy. The chemical resistance was also extensively studied against sodium hydroxide, nitric acid, and sulfuric acid. The changes in morphology, chemical elements, mass, volume, and molecular structures were investigated rigorously for pristine epoxy and its composite with HOFA at 1.6 wt %. After exposure to these chemicals for 21 days, the tested properties of the epoxy-flooring/HOFA composite showed better chemical resistance than that of the pristine epoxy. Where the epoxy-flooring/HOFA composite showed a surface with low cracks and blistering, it showed lesser changes in mass and volume and fewer molecular structure changes. These results indicated that it is possible to use this multifunctional composite for several applications, including the petrochemical industry, radiation shielding, construction, and automobiles.

Determination of scale deposition in a flare line by neutron back-diffusion.

Flares are used in the oil industry and other industries to dispose of waste gasses by burning. Damaged or blocked flares can lead to incomplete combustion and the release of contaminating gasses into the atmosphere. In this study, the neutron back-diffusion technique was used to measure the scale inside a flare stack. The neutron source employed was 241Am-Be with an activity of 1.11 × 1011 Bq (3 Ci), and a BF3 slow neutron detector. Scanning was conducted for scale in the stack at a refinery. Back-diffused neutron counts were doubled when moving from no scale to a scale thickness of about 17 cm. The scale thickness measured up to 20 cm and a change in the thickness of about 0.25 cm could be detected in a counting time of 1 min. The counting system weighed about 3 kg and it allowed scanning at a high stack elevation. The source employed yielded a total dose of 0.12 mSv h-1 at 1 m, which is significantly smaller than the doses from sources used in industrial radiography.