Graphitization and Performance of Deadman Coke in a Large Dissected Blast Furnace

The graphitization and performance of deadman coke in the blast furnace hearth have an essential influence on the longevity of the blast furnace. In this paper, coke samples were obtained from various heights in a hearth during the overhaul of the blast furnace. The voidage, particle size, graphitization degree, microstructure, and structure evolution of multiple cokes were analyzed through digital image processing, XRD, Raman spectra, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS). The graphitization results were compared with feed coke, tuyere coke, cohesive zone coke, and deadman coke in reference, and the main findings were analyzed. The following results were obtained. First, the voidage of deadman coke increased and then decreased with the increase of the depth while the particle size continued to decrease. In addition, the consumption rate of coke as a carburizer, reductant, and heart source was 8.47, 30.95, and 60.58%, respectively. Second, the graphitization degree of deadman coke was extremely high and showed a trend of first increasing and then decreasing. Finally, the evolution mechanism of coke graphitization was proposed. Molten iron, alkali metal, temperature, and mineral were the crucial factors that affect the graphitization of coke. The turning point of the graphitization degree was related to the buoyancy of the hearth.

[Treatment of multiple condyloma acuminatum of the coronary sulcus with sleeve circumcision of prepuce and coronary sulcus skin (a report of 35 cases)]

OBJECTIVE

To evaluate the effectiveness of sleeve circumcision of prepuce and coronary sulcus skin in the treatment of patients with multiple condyloma acuminatum (CA) of coronary sulcus of penis.

METHODS

In a randomized clinical control study, 35 patients were randomized to the treatment group and received sleeve circumcision of prepuce and coronary sulcus skin. 34 patients were randomized to the control group, received electric cauterization of verrucae plus the general circumcision. The recurrence of CA was evaluated in follow-up visit within three months after the treatment.

RESULTS

The stitches were taken out 10.2 days after operation in the treatment group, and 8.1 days in the control group. There were no complication in the treatment group, the average healing time of electric cauterization wound was 19.4 days in the control group. There was a statistically significant difference in the recurrence rate of CA between the treatment group and the control group (5.7% vs 26.5% , P <0.05).

CONCLUSIONS

The sleeve circumcision of prepuce and coronary sulcus skin is more effective than electric cauterization of verrucae plus the general circumcision in the treatment of patients with multiple condyloma acuminatum of coronary sulcus of penis.