Effectiveness of fluidized lime in the desulfurization of hot metal in 300-t casting ladles

Sichen

2014

The desulfurization abilities of some commonly used agents, namely fluidized CaO, CaC 2 , commercial-CaO, Mg, MgO, CaO Á MgO, and mixtures of commercial-CaO-Mg were studied and compared under the same experimental conditions in a laboratory furnace at 1773 K. The desulfurization mechanisms of CaO Á MgO, commercial-CaO, and mixtures of commercial-CaO and Mg were also studied. While fluidized CaO showed the best performance, commercial-CaO mixed with 20 mass% Mg achieved the second best desulfurization. Mg-granules performed slightly better than CaC 2 and commercial-CaO, but somewhat less satisfactory compared to fluidized CaO and commercial-CaO-Mg mixtures. Since only the CaO portion in CaO Á MgO functioned to take up sulfur, additional 70% mass had to be added to achieve the same desulfurization level. The poor ability of commercialCaO in comparison to fluidized CaO powder was due to both its less reactive surface and agglomeration of the particles.

Section: Discussioncontrasting

confidence: 73%

Study on Desulfurization Abilities of Some Commonly Used Desulfurization Agents

Sichen

2014

“…In some of the tests, Mg addition is accompanied or followed by CaO or CaC 2 additions. [1,[4][5][6][7][8][9] How the different agents help each other in desulfurization is still uncertain. Because of the experimental conditions employed, it is very difficult to understand the exact role of Mg in desulfurization, especially when Mg-CaO mixture is employed, and the addition is carried out under industrial conditions (usually in a short period).…”

Section: Mg þ S ¼ Mgsðsþ ð 1þmentioning

confidence: 99%

“…Calcium oxide, calcium carbide, and magnesium are the agents commonly used for this task. A number of research works on hot metal desulfurization can be found in the literature . Although magnesium and magnesium–CaO mixtures have been used with success in steel plants, the mechanism of the desulfurization using these agents is still not well known.…”

Section: Introductionmentioning

confidence: 99%

“…Whether Mg functions in the form of gas bubbles taking down the sulfur content directly or by increasing the sulfide capacity of the slag is always a question. In some of the tests, Mg addition is accompanied or followed by CaO or CaC 2 additions . How the different agents help each other in desulfurization is still uncertain.…”

Section: Introductionmentioning

confidence: 99%

“…A number of research works on hot metal desulfurization can be found in the literature. [1][2][3][4][5][6][7][8][9][10][11][12] Although magnesium and magnesium-CaO mixtures have been used with success in steel plants, the mechanism of the desulfurization using these agents is still not well known.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Functions of Mg and Mg–CaO Mixtures in Hot Metal Desulfurization

Nortier

Sichen

2013

The mechanisms of hot metal desulphurization using Mg and Mg-CaO mixtures were studied in a newly designed setup. It was found that most of the added Mg quickly escaped in 2 seconds. MgS was not formed by homogeneous nucleation but by its formation on the MgO particles originated from oxide shell of the Mg particles. When tiny CaO particles (Flucal) were added together with Mg, the particles efficiently transformed to CaS. It was found that Mg-gas helped the distribution of the CaO in the hot metal and improved the kinetic condition. Most of the CaO particles smaller than 10 μm were completely transformed to CaS whereas CaO particles >10 μm still had CaO in the centre after 20 s. The CaO particles as nuclei were also found to help Mg gas in forming MgS. Under the present experimental conditions, a mixture of about 20-30mass% Mg-80-70mass CaO % provided a good utilization of the flux. The reaction products distributed quite well over the whole sample. However, this ratio would need further study in a reactor, as the kinetic conditions would differ considerably. The optimized ratio is expected to be a function of the size and geometry of the reactor, the position and the depth of the addition, the manner of addition and more.

Study on the Possibility of Using ZnO for Hot Metal Desulfurization

Nortier

Glaser

et al. 2012

The possibility of using ZnO for desulfurization in hot metal has been evaluated. A experimental setup has been designed so that different desulfurizing agents could be added to hot metal for evaluation of their desulfurizing power. Additions of ZnO into the hot metal under various experimental conditions shows no effect on desulfurization. The results are in contradiction to the suggestion found in literature. A thorough examination of the thermodynamic data employed by the previous work has been carried out.