Selective removal of As from arsenic-bearing dust rich in Pb and Sb

The selective removal of arsenic from arsenic-bearing dust containing Pb and Sb in alkaline solution was studied. The influence of Na OH concentration, temperature, leaching time, liquid to solid ratio, and the presence of elemental sulfur on the dissolution of As, Sb and Pb in Na OH solution was investigated. The results indicate that the presence of elemental sulfur can effectively prevent leaching of lead and antimony from arsenic. The Sb2O3, As2O3 and Pb5(AsO4)3 OH in the raw material convert to NaSb(OH)6 and PbS in the leaching residue, while arsenic is leached out as As(Ⅲ) or As(Ⅴ) ions in the leaching solution. Arsenic leaching efficiency of 99.84% can be achieved under the optimized conditions, while 97.82% of Sb and 99.97% of Pb remain in the leach residue with the arsenic concentration of less than 0.1%. A novel route is presented for the selective removal of arsenic and potential recycle of lead and antimony from the arsenic-bearing dust leached by Na OH solutions with the addition of elemental sulfur.

One-step and selective extraction of nickel from nickel-based superalloy by molten zinc

Nickel-based superalloy was treated with molten zinc for the selective extraction of nickel.The effects of heating temperature,heating time,and the mass ratio of zinc to superalloy on the extraction of metals in the superalloy were investigated.An extraction rate of 95.2%for nickel,55.4%for iron and 30.4%for chromium,but low extraction rates of the refractory metals(titanium(Ti),molybdenum(Mo),and niobium(Nb))were obtained under the optimal conditions of the heating temperature of 850℃,the heating time of 4 h,and the zinc/superalloy mass ratio of 10:1.In the subsequent vacuum distillation process,the obtained nickel alloy contained nickel with a purity of 73.5 wt.%after zinc removal.Moreover,the recovered zinc after the distillation process had a purity of 99.9 wt.%.The results of the investigated process indicated the possibility of extracting nickel directly from nickel-based superalloy scraps.

Employing magnesium−lead melt for synergetic and selective extraction of copper from copper−cobalt alloy

This research aims to extract Cu from Cu-Co alloy with high efficiency and selectivity by employing binary Mg-Pb melt. The optimal conditions for the extraction of Cu were determined. The results showed under optimal conditions, 96.5% of Cu in the Cu-Co alloy could be selectively extracted after treatment at 800 ℃ for 1 h, with the extraction rates of only 0.2% Fe, 0.6% Co, and 1.4% Si. The dissolution mechanism involved the counter diffusion of Mg/Pb and Cu across the diffusion zone of the Cu-Co alloy, and Mg in the binary Mg-Pb melt played a major role in the selective dissolution of Cu, especially at the dissolution forefront. The rate-controlling step of the extraction was dominated by the interfacial reaction.

Effect of oxycodone hydrochloride injection preemptive analgesia on serum inflammatory factors, neurotransmitter index and immune function in patients with laparoscopic cholecystectomy

Objective:To investigate the effect of oxycodone hydrochloride injection preemptive analgesia on serum inflammatory factors, neurotransmitter index and immune function in patients with laparoscopic cholecystectomy.Methods: According to random data table, 113 patients undergoing laparoscopic cholecystectomy were divided into control group (n=57) and observation group (n=56), patients in the control group were treated with sufentanil citrate injection analgesia, and the observation group patients were given oxycodone hydrochloride injection analgesia, level of serum inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6)], neurotransmitter index [5-hydroxy tryptamine (5-HT), P substance] and immune function index [CD4+, CD8+, CD4+/CD8+] of two groups between preoperative and postoperative 1d were compared.Results: There were no significant difference in level of TNF-α, IL-6, 5-HT, P substance, CD4+, CD8+ and CD4+/CD8+ between the two groups preoperative. Compared with the level of the same group preoperative, at postoperative 1 d level of TNF-α, IL-6, 5-HT, P substance, CD8+were significantly increased, moreover level in the observation group were significantly lower compared with the control group, the difference was statistically significant;Postoperative 1 d, level of CD4+, CD4+/CD8+ in the two groups were significantly lower than the preoperative level within the group, and the observation group was significantly higher than the control group.Conclusion: Oxycodone hydrochloride injection preemptive analgesia in laparoscopic cholecystectomy can effectively reduce serum inflammatory factors and neurotransmitter index release, improve immune function, has an important clinical value.