4results about How to "Prevent slagging" patented technology

This invention relates to a protective slag for sulfur-containing free-cutting steel crystallizers using photovoltaic silicon mud and its preparation method. The protective slag of this invention contains, by mass percentage, 30.6–31.6 wt% CaO, 36.7–37.7 wt% SiO2, 6.1–7.1 wt% Al2O3, 8.2–9.2 wt% Na2O, 5.0–6.0 wt% F, and 9.0–10.0 wt% C. 固 H2O up to 0.5 wt%; C 固 The carbon in the protective slag is fixed. Raw materials include 7-9 wt% silica mud, 14-16 wt% blast furnace slag, 24-26 wt% phosphorus slag, 14-16 wt% silicate cement, 4-6 wt% wollastonite, 10-12 wt% soda ash, 2-4 wt% fluorite, 6-8 wt% cryolite, and 10-12 wt% carbon powder. The preparation method includes batching, slurry preparation (solid content 40-45%), spray granulation (spray gun orifice diameter 1.0-1.5 mm, inlet temperature 450-480℃), and post-treatment. This invention enables the utilization of photovoltaic silica mud, reducing the cost of protective slag containing silica mud by 870 yuan per ton, and increasing the flaw detection pass rate of continuously cast billets from 25.99% to 55.17%, thus possessing both energy-saving and emission-reduction value and a circular economy value.

This utility model relates to the field of refractory materials technology for metallurgical equipment, and in particular to a ladle tank bottom lining structure with a gradient thickness, including ladle nozzle seat bricks, vertically laid tank bottom bricks, and lining wall bricks. The vertically laid tank bottom bricks include center bricks, intermediate bricks, and edge bricks, which are laid in a ring from the ladle nozzle seat bricks towards the edge of the ladle tank bottom, with the thickness d of the center bricks, intermediate bricks, and edge bricks increasing by 30mm to 40mm respectively. The lining wall bricks are set at the bottom of the inner wall of the ladle tank and connect with the edge bricks, with the thickness e of the lining wall bricks decreasing by 15mm to 20mm from bottom to top. The beneficial effects of this utility model are: by optimizing the thickness distribution, it improves thermal shock resistance, structural stability, and service life, and increases the steel loading capacity.

The present application relates to the metallurgical technology field, especially relate to a kind of off-oven refining combined vacuum arc remelting preparation ultra-pure stainless steel method.The preparation method of the present application is by AOD station to transfer the crude molten steel obtained by EAF smelting to AOD refining furnace to blow oxygen refining, pre-reduction refining slag is CaO-CaF2-SiO2-MgO slag system;After pre-reduction treatment, reduction treatment is carried out, and the reduction refining slag is CaO-CaF2-SiO2-MgO slag system;The molten steel after reduction treatment is transferred to VD furnace for vacuum treatment, and the treated molten steel is transferred to ladle, then poured into mold, and ingot is obtained;After ingot is forged into electrode, ultra-pure stainless steel is prepared by VAR, with ultra-high cleanliness, coarse system inclusions is 0 level, fine system A+B+C+D inclusions≤0.5 level, effectively realize the accurate low control of aluminum content in steel, and simultaneously reduce the oxygen content and non-metallic inclusion content in steel, finally prepare high-quality ultra-pure stainless steel.