In the area of hot metal desulphurization, we are ready to offer to our customers any work scope ranging from the improvement of the existing equipment to delivery of a new plant on a "turnkey" basis.
At present the most widespread technologies of hot metal desulphurization in the ladle are the processes involving injection of “pure” (without additives) granular magnesium and milled magnesium mixed with passivator (lime, calcium carbide and other materials).
The desulphurization technology by means of injection of powdered magnesium, lime, calcium carbide and other materials was developed and introduced in the steel mills of the Soviet Union in 1969-1971.
The proposed technology and hot metal desulphurization equipment was designed by the Institute of Ferrous Metal in Dnepropetrovsk and by the Institute of Titanium in Zaporozhye starting from 1972.
Nine major industrial desulphurization plants were built using this technology in the Soviet Union. The total capacity of these plants is over 15 million tons of pig iron per year and reduction of the sulfur content in iron makes up to 0.002-0.010%.
Presently 77 new plants of hot metal desulphurization using the granulated magnesium without additives method are successfully operated at steel mills in China. The total capacity of these plants is over 96 million tons of pig iron per year. Evaluation of the existing facilities operation has shown that compared to the other technologies injection of granular magnesium is notable for the lowest total cost of iron treatment (by 2.8-3.5 US dollars per ton of treated iron cheaper).
The hot metal desulphurization technology using granular magnesium is exemplified by the following values:
• Agent (magnesium) recovery degree – up to 95%
• Hot metal temperature before treatment - as per Buyer’s specification
• Processed hot metal weight - as per Buyer’s specification
• Sulphur initial content in hot metal - as per Buyer’s specification; sulphur final content in hot metal – any required by the buyer, up to 0.002%
• Magnesium specific flow rate – depends on the initial and specified final sulphur content and processing conditions, and mainly amounts to 0.2-0.6 kg/t of hot metal
• Magnesium injection rate – adjustable within the range 6-12 kg/min (basically)
• Injection time - 3-10 min (basically) • Hot metal temperature decrease - 5-15° С
• Required gas pressure in feeding network – 1.0 MPa
• Gas-carrier flow rate – 0.5 Nm3/t of hot metal
• Gas flow rate during magnesium injection – up to 140 Nm3/hr
• Gas flow rate during preparation for magnesium injection – up to 160 Nm3/hr
The other process parameters including know-how are transferred to the buyer along with the process and technical documentation under the Contract.