To explain the unusually high selectivity of copper catalysts toward linolenate, model compounds were hydrogenated (150 C and atmospheric pressure) and the reaction products analyzed. Products varied depending upon location of the double bonds. Monoenes were not reduced by copper chromite except when the double bond was next to a carboxyl group. Dienes with isolated double bonds also were not r...

Zero-valent iron (ZVI) and green rusts can be used as reductants to convert chromium from soluble, highly toxic Cr(VI) to insoluble Cr(III). This study compared the reduction rates of Cr(VI) by ZVI and two carbonate green rust phases in alkaline/hyperalkaline solutions. Batch experiments were carried out with synthetic chromate solutions at pH 7.7-12.3 and a chromite ore processing residue (COP...

baft ophiolite mélange is a part of naein-baft ophiolite (southeast of kerman province in iran). serpentinites from baft ophiolite mélange contain different types of spinels such as chromite, chromespinel, ferritchromite and magnetite which can reveal different stages of evolution in host serpentinites. the compositions of baft chromites show that they belong to podiform chromitites that may ha...

in this study, copper chromite (cucr2o4) nanoparticles was prepared by inverse co-precipitation method. in this method, cupric nitrate trihydrate, (cu (no3)2.3h2o) and chromium nitrate nonahydrate, (cr (no3) 3.9h2o) with a mole ratio of 1:2 were used. characterization of cucr2o4 nanoparticles was performed by fourier transform infrared spectroscopy (ft-ir), raman spectroscopy, x-ray diffraction...

The optical properties of coatings pigmented with different black colorants were systematically investigated and their surface temperatures and cooling energy savings were estimated. The black coatings pigmented with chromite iron nickel black and manganese ferrite black spinel colorants are not cool enough to be energy efficient cool black coatings. The cool black coatings pigmented with NIR-t...

In the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. Since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. Different goals may be used for determining optimum cut-off grade. One of...

Petrology and Mineral Compositions: The fresh, pale gray interior of this specimen has multiple shock fractures (with very minor calcite coatings) and some thin glass veinlets (Figure 2). This rock is a poikiloblastic recrystallized breccia, with larger grains of plagioclase (~70%) enclosing much smaller grains (less than 100 microns across) of pyroxene (~20%), olivine (~10%) and accessory Ti-c...