EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime

A new electric arc furnace （EAF） steelmaking process with increasing hot metal charging ratio and improving slagging regime simultaneously was developed and applied in a 50 t electric arc furnace for more than a year at No. 1 Steelmaking Plant of Shanxi Taigang Stainless Corporation Limited. The essential fact of the new EAF steelmaking process was to charge hot metal in two portions or steps： firstly, 35wt%-40wt% hot metal was pretreated by blowing oxygen in a specially designed reactor for decar burization and improving hot metal temperature and melting premelted slag; secondly, 30wt% hot metal was charged into EAF with high basicity refining slags from ladle furnace （LF）-vacuum degassing furnace （VD） refining process. The results show that the hot metal charging ratio can reach to about 65wt%-70wt% for the new EAF steelrnaking process; meanwhile, the tap-to-tap time of a 50 t EAF can shorten by 5-10 min, the electricity consumption can decrease by 35-50 kW·h/t, the lime consumption can reduce by 10.5 kg/t of molten steel, and the content of harmful heavy metals in molten steel can be easily controlled to less than the upper limits of aimed steel specification or grade compared with the traditional EAF steelmaking process. In addition, the dephosphorization ability shows a slight strengthening, however, a small degree of lessening for desulphurization ability is observed for the new EAF steelmaking process, but the weakness of desulphurization ability cannot become an obstacle to its further application since a stronger desulphurization ability can be achieved during secondary refining of LF coupled with VD after EAF steelmaking process.

Changes in peripheral blood inflammatory factors(TNF-α and IL-6) and intestinal flora in AIDS and HIV-positive individuals

Objective:In this study,we investigated the changes in peripheral blood inflammatory factors and intestinal flora in acquired immune deficiency syndrome(AIDS)and human immunodeficiency virus(HIV)-positive individuals(AIDS/HIV patients),and explored the relationships among intestinal flora,peripheral blood inflammatory factors,and CD4^+T lymphocytes.Methods:Thirty blood and stool samples from an AIDS group and a control group were collected.The levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)were determined by enzyme-linked immunosorbent assay(ELISA),and the number of CD4^+T lymphocytes by a FACSCount automated instrument.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to determine the messenger RNA(mRNA)levels of Bifidobacterium,Lactobacillus,Escherichia coli,Enterococcus faecalis,and Enterococcus faecium.Correlations among intestinal flora,inflammatory factor levels,and CD4^+T lymphocyte values were evaluated using the Spearman correlation coefficient.Results:The levels of TNF-αand IL-6 in the AIDS group were higher than those in the control group,while the number of CD4^+T lymphocytes was lower.The amounts of Bifidobacterium and Lactobacillus in the AIDS group were significantly lower than those in control group,while the amounts of E.coli,E.faecalis,and E.faecium were much higher.The amounts of Bifidobacterium and Lactobacillus were negatively correlated with the content of TNF-αand IL-6 and the CD4^+T lymphocyte count,while those correlations were reversed for E.coli,E.faecalis,and E.faecium.Conclusions:The intestinal microbiota of AIDS/HIV patients were disordered,and there was a correlation between the amount of intestinal flora and the number of CD4^+T lymphocytes and the levels of TNF-αand IL-6.