The final step in the rebuild of Minmetals Yingkou Steel Plant’s meltshop has now been achieved.

The RH 2 has successfully been hot-tested at the plant, which is based in northeast China.

The Covid-19 pandemic made life harder for the team from CISDI. But with strict health and hygiene controls in place, it took 85 days to complete all equipment installation, accelerating provisions for the hot test.

Working on an EPC basis, CISDI had already built a new ladle furnace, KR desulphurisation plant and a super-thick slab caster at the plant, and rebuilt three BOFs before setting up and testing the RH vacuum refining process.

This new RH 2, with a nominal vessel capacity of 120 tonnes, has an annual production capacity of 900,000 tonnes.

The main steel grades it will process are laminar tearing resistant steel, bridge steel, shipbuilding steel, armour steel, advanced pipeline steel, boiler steel, quality carbon steel and low-alloy high-tensile structural steel.

Refined liquid steel will be charged into the downstream super-thick slab caster, which is now achieving mass production.

A major refining procedure for clean steel production, the RH process relies on a low vacuum and hydrogen content. Yingkou RH 2 has achieved a 12.6Pa ultra-low vacuum degree and 0.84ppm hydrogen content in refined liquid steel. Both hot test results break records in China.

A number of CISDI specialist products have been applied:

⬧         SCAP multi-functional top lance - capable of a long range of oxygen blowing and a strong aggregation, it enables burning with a long, stable flame. The lance’s powder injection is far-reaching and the injected particles show a good permeability. 

⬧         Patented immersion tube - an integrated body able to expand the inner diameter, prevent liquid steel from splashing and protect the vacuum channel from blocking. As a result, the gas flow becomes larger, reducing the melting time.

⬧         Vacuum pump system - consisting of a steam pump plus a water circulating pump, this enables 20 per cent of the meltshop’s excess steam to be reused by the pump system.

The steel ladle ready to rise up into the RH 2

The RH 2 refining at Minmetals Yingkou meltshop