In this research, the high arsenic content dust of copper smelting, as a raw material, the extraction of copper and arsenic from the high arsenic content dust in the leaching system containing acidic and alkaline compounds was investigated. Meanwhile, the effects of acid/alkaline initial concentration, liquid to solid ratio, leaching temperature, leaching time on the leaching rate of copper and arsenic were studied. The optimum conditions for the leaching of high arsenic content dust and preparation of copper arsenate were determined. The results showed that acidic/alkaline leaching of high arsenic content dust was particularly effective. 93.2% of the copper, and 91.6% of the arsenic were leached in an acidic leaching process and 95% of the arsenic, while less than 3% of the copper, less than 5% of the antimony, less than 2% of the bismuth was also leached in an alkaline leaching process. A new method (the parallel flow drop precipitate method) was developed in the synthesis of copper arsenate process. The parallel flow drop method was employed to adjust the molar ratio (copper to arsenic) of the mixed solution of the acid-leaching solution and the alkali-leaching solution by taking the drop acceleration of an acidic leaching solution and an alkaline leaching solution at 10 mL/min and 12 mL/min, at a temperature of 60°C and a reaction time of 1 h. Copper arsenate was prepared by mixing an acidic leaching solution and an alkaline leaching solution. The main phases of copper arsenate were CuHAsO4·1.5H2O and Cu5As4O15·9H2O. Copper arsenate contained 30.13% copper and 31.10% arsenic.
Thermal buckling behavior of a functionally graded material (FGM) Timoshenko beam is studied based on the transformed-section method. The material and thermal properties of the FGM beam are assumed to vary across the beam thickness according to a power-law function, a sigmoid function and an exponential function. The results of buckling temperature for the FGM beams with respective temperature-dependent and temperature-independent properties under uniform and non-linear temperature rises are presented. Some results are compared with those in the published literature to verify the accuracy of the present work. The effects of the material distributions, temperature fields, temperature-dependent properties and slenderness ratios on the thermal buckling behaviors of FGM beams are discussed. It is believed that the present model provides engineers with a simple and effective method to study the effects of various parameters of the FGM beam on its thermal buckling behavior.
We assessed culturable soil microfungal diversity in various habitats around Hornsund, Spitsbergen in the High Arctic, using potato dextrose agar ( PDA) medium. Thermal growth classification of the fungi obtained was determined by incubating them in 4 ° Cand 25 ° C, permitting separation of those with psychrophilic, psychrotolerant and mesophilic characteristics. In total, 68 fungal isolates were obtained from 12 soil samples, and grouped into 38 mycelial morphotypes. Intergenic spacer regions of these morphotypes were sequenced, and they represented 25 distinct taxonomic units, of which 21 showed sufficient similarity with available sequence data in NCBI to be identified to species level. Soil under ornithogenic influence showed the highest species diversity, including sequences assigned to Mortierella macrocystis, M. elongata, Mortierella sp., Cudoniella sp., Varicosporium elodeae , Beauveria bassiana , Geomyces pannorum , Penicillium sp. and Atradidymella muscivora . Fourteen taxa were classified as psychrophilic, seven mesophilic, and four psychrotolerant.