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The g-C3N4 (GCN) adsorbent with two different morphologies, coral (CGCN) and nano fiber (GCNNF), was synthesized and recruited for extraction and preconcentration of lead and copper metal ions by effervescent salt-assisted dispersive micro solid phase extraction procedure. The structures of the two adsorbents were affirmed by Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and Brunauer–Emmett–Teller analyses. The factors affecting the extraction efficiency were carefully studied and the optimum values of the parameters for both adsorbents were pH 6.5, adsorbent dosage 8 mg, desorption time 3 min, and the elution solvent 300 μL of 2 mol L−1 of HNO3. The detection limits of Pb(II (and Cu(II) ions for CGCN were 0.9 and 0.3 μgL−1 and for GCNNF were 1.56 and 0.7 μgL−1, respectively. The percent relative standard deviations were obtained to be 1.32% and 2.23% for CGCN (n = 3) and 1.24% and 2.29% for GCNNF (n = 3), respectively for the lead and copper metal ions. In addition, the adsorbents could be used up to 7 times without an imperative reduction in the percentages of analytes recovery. Finally, the performance of CGCN and GCNNF were used for preconcentrate of lead and copper ions in honey, canned fish, and human hair samples. [ABSTRACT FROM AUTHOR]

The extraction of lithium from a titanium wastes by selective acid leaching was explored. The preliminary leaching tests showed that diluted sulphuric acid could be used to leach lithium from the wastes. The recovery of lithium from a synthetic leach solution of the SMTC (spent melts of titanium chlorinators) using solvent extraction was studied. A number of extractants were investigated for the extraction of lithium and its separation from the other metals in the synthetic leach solution. It was found that amongst the three acidic organophosphorus extractants studied, D2EHPA performed best. With the organic system consisting of 0.05 M D2EHPA and 0.05 M TBP in Shellsol D70 under an A/O ratio of 5:1 at pH 0.25 and 40°C, over 97 % lithium was extracted and almost no iron and aluminium were co-extracted. The lithium extracted could be stripped from the D2EHPA/TBP system with 5 M NaOH to obtain LiOH product. [ABSTRACT FROM AUTHOR]

The article discusses about an effective system development for mining of thin deposits using small-sized self-propelled machines for high efficiency and completeness of mineral extraction. Furthermore, in this research are given the results of development of fine vein lodes by using sublevel system and high-performance, compact self-propelled machines. The developed technological scheme of ore extraction and delivery by self-propelled VSD is recommended to use in mining enterprises which develop vein deposits with varying thickness of ore and a wide range of occurrence angles. [ABSTRACT FROM AUTHOR]