background: in megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. the use of high-density concrete decreases the required thickness of the concrete barrier hence, its disadvantage is its high cost. in a nuclear reactor, neutron radiation is the most difficult to shield. a method for p...

nakhlak lead mine is located at the nakhlak mountain 55 km ne of anarak town in isfahan province. the mineralogy is simple; galena and barite are the main primary minerals and cerussite is the main secondary mineral. sphalerite, pyrite, chalcopyrite, tetrahedrite-tennantite and acanthite occur as minor and trace mineral inclusions in galena. secondary minerals are anglesite, plattnerite, wulfen...

Environmental concerns regarding the use of certain chemicals in the froth flotation of minerals have led investigators to explore biological entities as potential substitutes for the reagents in vogue. Despite the fact that several microorganisms have been used for the separation of a variety of mineral systems, a detailed characterization of the biochemical molecules involved therein has not ...

The influence of microwave treatment on the surface roughness, hydrophobicity, and chemical composition of galena was studied. The pure galena specimens and purified galena concentrate were used in this work. A conventional multi-modal oven (with a frequency of 2.45 GHz and a maximum power of 900 W) was used to conduct the experiments. The results obtained from the atomic-force microscopy analy...

The primary coexisting mineral with galena is sphalerite. Hence, it critical to selectively separate from sphalerite by flotation. In this work, thiourea and related derivatives as potential flotation collectors for separating were investigated. Thiourea its found be effective selective in batch studies of a single mineral, 1,1-diphenylthiourea (11DTA) emerging the best choice. Galena has super...