Phase 1 New Special Steel Project of BAOWU-Masteel was Totally Put into Production

On June 6^th, the overall phase 1 new special steel project of BAOWU-Masteel was successfully put into production, among which hot metal desulfurization EPC project, steelmaking EP project, LF refining EPC project, square and round billet continuous casting EPC project were undertaken by WISDRI. Once phase 2 project is completed, Masteel will join the ranks of premium special long product suppliers across the world with the largest individual special steel production complex in China.

Guided by green, intelligent practices in steelmaking, WISDRI has applied state-of-the-art technologies to phase 1 project for high efficiency and environmental protection.

Hot metal pre-treatment

The lifting car of hot metal desulphurization system is equipped with disc spring clamping device and pneumatic motor for emergency lifting, ensuring stable and reliable operation. The impeller is equipped with online slag removal device, and able to serve more than 300 heats.

As dedicated desulphurization process model, automatic slag removal technology, automatic desulphurizing agent injection technology and automatic calculation and adjustment of stirring and feeding parameters are adopted by the hot metal pre-treatment system, it realizes one-click desulphurization with desulfurization rate≥95%, desulfurization capacity W(S)≤0.001%, and treatment cycle≤36min.

One-click steelmaking

The automatic steelmaking system stands at a 90%-odd hit rate in end-point carbon content and liquid steel temperature, and effectively shortens tap-to-tap time by 2 minutes, reduces ferrous charge consumption by 5kg/t and cuts down on reblowing rate with the static melting bath carbon content & temperature prediction and anti-splash technology.

The automatic tapping system applies the machine vision technology and the sensor fusion technology to automatic positioning of ladle car, slag detection at tap hole and lip ring, and control of tilting angle, completely replacing manual tapping operation with detection accuracy at tap hole and lip ring＞99% and success rate of automatic tapping＞95%.

Intelligent steelmaking platform

The intelligent steelmaking platform fulfils multiple functions such as automatic identification of hot metal ladle and liquid steel ladle, logistics tracking, production scheduling, dynamic dispatching, and heat temperature prediction, providing strong technical support for cost reduction and benefit gain.

Billet surface quality and inner quality control

An automatic control system of liquid steel in tundish and mold is adopted to maintain a constant level, realizing the fully automatic start of casting. During casting, the level control accuracy of the mold reaches +/-2mm, and strand breakout and overflow prevention functions are provided to improve casting quality.

The mold electromagnetic stirring system (M-EMS) and the final electromagnetic stirring system (F-EMS) come with larger stirring currents and frequencies to ensure strand quality.

The combination of double-stand and single-stand withdrawal and straightening machines accommodates to the process needs of special steel for soft and heavy reductions.

Unmanned billet run-out system

With various cut-to-length methods such as laser cut-to-length, infrared cut-to-length and withdrawal and straightening machine encoder counting, the billet length error is controlled within +/-20mm.

The billet continuous casting line is equipped with a variety of automatic delivery functions, including direct hot charging roller table, walking beam cooling bed, emergency billet storage stand, two-bay run-out system and central storage of the same heat. The run-out roller tables in both bays are equipped with a cross transfer car respectively, which runs simultaneously during normal production, and serves as each other’s backup when one of the two fails.

The run-out area is equipped with the image recognition and tracking system, the cluster limit system, and the whole-area laser limit system to improve the reliability in billet automatic tracking.

BOF gas dry dedusting and recovery technology

Compared with the wet type, the dry dedusting and recovery system recycles coarse dust while reducing water and electricity consumption by an estimated 50% respectively, and saving millions of yuan in operation cost every year.

The control system regulates micro-differential pressures at lip ring according to changes in smelting stage, realizing almost zero leakage and explosion during normal production.

With an integrated dust removal system combining high-efficiency electrostatic precipitator and gas washing plant, the carbon emissions from the flare stack is lower than 10mg/m³.

Comprehensive secondary and tertiary fume collection technology

Based on how secondary and tertiary fumes are generated and dispersed, a novel-type dog house and a roof canopy hood to collect fumes with collection efficiency 15% higher than its counterpart are adopted. It effectively reduces energy consumption of running equipment, and delivers clean production by cutting dust emissions to below 10mg/Nm³.

The gas flow of the dust removal system is interlocked with the production, saving over 15% of total flow.