Here we take charge to share our expertise on day to day issue a steel maker faces.
Significant indirect benefits which arise out of killed steel and reduced tapping temperatures are:
Reduction in casting related issues like blowholes and pinholes
Reduction in rebar losses from casting defects
Shorter heat time – Higher production
Longer lining life – Lower refractory cost – Larger melt size in the extra heats gained
Lower rolling mill rejections – Less split rebars
Vastly improved steel quality – Dramatic drop in blowholes and pinholes in the billet
Increased casting speed due to lower tapping temperatures – Lower rhombicity in billets and less casting defects
These will become evident after continued use of Remix 55 & INSUTAL 4A. The figures used are conservative and there should be further lowering of tapping temperatures (Approximately 20 – 40 C) after confidence build up on the shop floor.
1.Synthetic Slag Deoxidizer - Remix 55
REMIX 55, is a synthetic slag deoxidizer, tailor-made for controlling the [O] ppm, of steel through Induction furnace route.Some Advantages:
Significantly improved % Mn recovery- i.e. 10 to 15% lower addition rate of ferroalloys
Ease of slag removal, as the slag agglomerate and becomes viscous.
Very low to nil, Mn drop in the ladle.
2.Ladle and tundish covering compound - Insutal 4 A
INSUTAL 4 A is an insulating refractory powder product used as a cover for molten steel. Some Advantages:
Reduces radiation heat losses from the top surface of the Tundish & Ladle.
It helps to maintain consistent metal temperatures in the Tundish.
The material expands in volume 4 times on application and improves spreadability.
Ramming mass is a pre-blended Dry vibratables refractory made from a selected mix of SILICA GRAINS.
This blend of grains along with a binder, BORIC ACID forms the working lining in an Induction furnace
used for melting steel. The application process involves placing a cylindrical steel former within the
furnace with equally spaced gaps on all sides. Then the ramming mass is filled into the gaps between the
furnace wall and the steel former. This ramming mass is compacted with an electro vibrator. Once the
lining is ready, steel scrap is charged, and the power is slowly turned up. Following a suitably designed
heating cycle, the lining SINTERS (hardens) and then the steel scrap melts at approximately 1650 °C.
Then the lining is ready to use, and scrap is molten and cast into billets or ingots. One lining may last for
5 to 50 cycles of melting, depending on the grade of steel cast, charge mix, melting time and the tapping
Silica rocks are brought in from captive mines to our crushing plant in Jaipur. After initial screening
which involves various chemical and physical analysis, the rocks are crushed and sized in various grain
fractions. The various grains fractions are stored in bulk silos. Then the batching plant prepares a batch which
consists of a mix of various grain fractions along with the requisite percentage of BORIC ACID as per the
desired recipe. This batch is then mixed to a uniform consistency and packed in bags. The installed
capacity of our crushing, sizing, and mixing plant is 200,000 MT per annum
BORIC ACID is introduced in the ramming mass to provide adequate sintering without a marked
reduction in the refractoriness of the ramming mass. The production process of ramming mass involves
the addition of 0.2 to 5.0% of Boric Acid, which enables the sintering of the crucible lining. Boric acid
starts melting at 171 °C and separates to Boric oxide and water. This Boric oxide further reacts with the
SiO2 in the Ramming mass at 440 °C and forming a borosilicate melt. This small percentage of melt
formed binds the loose grains in the lining giving it strength. This is the mechanism of formation of a
dense contact layer with molten metal and slag, which prevents the penetration of liquid metal into the
lining and slows down impregnation of crucible material.