HIGH-CARBON FERRONICKEL DEPHOSPHORIZATION SIMULATION PROCESS

• Main Author: RISA RIDWAN JANUARI CHAIRIL (NIM : 12506024), M
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23137
• Institution: Institut Teknologi Bandung

Dephosphorization process in steel industry has been widely researched and some models have been developed to simulate the process. At PT Antam, dephosphorization process has been applied in LD Converter to produces low-carbon ferronickel (LC-FeNi). For high-carbon ferronickel (HC-FeNi), phosphorus content <0.025% is desired at the end of the process. Currently, the phosphorus content in the nickel ore showed an increasing trend. Phosphorus content at tapping SAF can reach 0.04 to 0.05%. If the customer wants a HC-FeNi product with low phosphor content, PT. Antam shall deliver LC-FeNi product because FeNi HC-product still have high phosphorus content. <br /> <br /> <br /> <br /> In this simulation, the dephosphorization process of HC-FeNi in order to reduce phosphorus content will be studied to fulfill the costumer requirement. Dephosphorization techniques on steel can be adaptated to reduce high phosphorus content in HC-FeNi. It will be reviewed the influence of temperature, basicity, weight of slag added, the activity of oxygen, constant rate of mass transfer and contact area with the surface of the slag to the amount of phosphate capacity, phosphorus distribution ratio and the percent of phosphorus on the hot metal at equilibrium. Further more, liquidus temperature of slag using ternary diagram CaO-SiO2-FeO system is also considered in this simulation. <br /> <br /> <br /> <br /> Simulation results showed that the dephosphorization process temperature can achieve optimum value at 1400 oC where that temperature is higher than the liquidus temperature of crude FeNi. Dephosphorization conditions can achieve optimum value with basicity 2 and can be increased again with the addition of CaF2 to reduce the melting point of slag. The optimum weight of slag based on the simulation results is 500 kg with assuming a constant rate of mass transfer of phosphorus content in slag is 0,02 cm/s and contact area with the surface of the slag equal to surface area of ladle (2,42 m2).