Development of iron ores sintering machine for blast furnace process

There must be proper means to sinter and, agglomerated iron ore concentrate before it can be further processed in the blast furnace. A Sintering machine of 5kg capacity of agglomerated ore was designed and fabricated using mild steel material, which was locally sourced. The machine was fabricated with a combustion chamber of 30 by 30 cm and with 15cm depth. It was also lined with refractory material to reduce the chamber to the volume of 3375 cm3. However, the sintering chamber was designed to have a truncated square pyramid shape to the volume of 2150 cm3 after lining with refractory material. The design was made to utilize coke and palm kernel shell char as fuel which will be ignited to produce heat into the sintered material by suction of the heat into the agglomerated sintered ore. Tests such as tumbler index, abrasion, and porosity test were carried out on the sintered products in agreement with ASTM E276 and E389 standards. The results from the test gave a tumbler index of 70.2% and 65.7% for coke and palm kernel shells respectively. Also, abrasion index of 5.1% and 4.6% for coke and palm kernel char, and porosity of 6.8% and 6.5% for coke and palm kernel char respectively. The results from the experimental test were in agreement with other research work. Therefore, the developed iron ore sintering machine has a better efficiency of producing sinter for blast furnace operation.

Application of the technology of induction chemical-thermal treatment to improve the physical and mechanical properties of tantalum

The results of the chemical thermal treatment (CTT) of tantalum in a solid carbon- containing medium in the temperature range from 1000 to 1300 °C were presented. CTT consisted in heating a workpiece with a working medium in a container made of a refractory material. The induction heating method was used for heating. After strengthening treatment, tantalum samples were characterized by increased hardness, which grew from 140 to 1100 HV0.02.

Thermodynamic Refractory Corrosion Model for Ferronickel Manufacturing

A thermodynamic model, based on SimuSage, was developed to simulate refractory corrosion between a magnesia-based refractory material and ferronickel (FeNi) slags. The model considers a theoretical cross-section of a refractory material to simulate a ferronickel smelter application. The current model is structured into 10 zones, which characterize different sectors in the brick (hot to cold side) perpendicular to the refractory surface with an underlying temperature gradient. In each zone, the model calculates the equilibrium between the slag and a specified amount of refractory material. The emerging liquid phases are transferred to subsequent zones. Meanwhile, all solids remain in the calculated zone. This computational process repeats until a steady state is reached in each zone. The simulation results show that when FeNi slag infiltrates into the refractory material, the melt dissolves the magnesia-based refractory and forms silicates (Mg,Fe,Ca)2SiO4 and Al spinel ((Mg,Fe)Al2O4). Furthermore, it was observed that iron oxide from the slag reacts with the refractory and generates magnesiowustite (Mg,Fe)O. Practical lab-scale tests and scanning electron microscopy (SEM)/Energy Dispersive X-ray Spectroscopy (EDS) characterization confirmed the formation of these minerals. Finally, the refractory corrosion model (RCM) ultimately provides a pathway for improving refractory lifetimes and performance.

Analysis and Prediction of Corrosion of Refractory Materials by Sodium Salts during Waste Liquid Incineration—Thermodynamic Study

Incineration of high-content sodium salt organic waste liquid will corrode the refractory material in the incinerator, causing the refractory material to peel off and be damaged. A thermodynamics method was used to study the thermodynamic properties of three common sodium salts (NaCl, Na2CO3 and Na2SO4) on the corrosion of refractory materials (MgO·Cr2O3, MgO·Al2O3, Al2O3, MgO and Cr2O3). The results determined that MgO has the best corrosion resistance and is not corroded by the three sodium salts. On this basis, the thermodynamic corrosion experiments of NaCl corrosion of magnesium oxide at three temperatures of 600, 1000 and 1200 °C were carried out. Analysis of the corrosion product by X-ray diffraction (XRD) showed no corrosion product formation. Studies have shown that thermodynamic calculation can accurately predict the thermodynamic mechanism of alkali metal corrosion to refractory materials, and MgO is a good anti-alkali metal corrosion refractory material.

Refractory material moisture metering when heating high-temperature units

The specifics of the drying process of the lining of hightemperature units are described, in particular, the average drying rate is analyzed. The adequacy of the proposed mathematical dependencies is confirmed by comparing the results obtained by calculation, and experimental data obtained at the laboratory bench. The research results can be used to develop a schedule for heating high-temperature units after major repairs to remove moisture.

Development of Empirical Correlation for Thermal Fatigue Life Cycle Prediction

Furnaces are most commonly used for melting of Iron and its various alloy materials. Induction furnaces are using electric power supply so they are more beneficial as no fuel is required. It is an extremely critical to find life span or life cycle of Induction Melting Furnace Wall under thermal load change conditions. The low cycle thermal fatigue life time L is depended upon various parameters like thickness of induction furnace refractory wall t, density of refractory material , inside film co-efficient outside film co efficient , thermal expansion coefficient outside temperature , specific heat of refractory material C, elasticity constant E, ultimate strength S, thermal conductivity of refractory material k, Volume V, time period of melting cycle τ. An expression for thermal fatigue life time of induction furnace melting wall is derived by dimensional analysis using bunkingham’s π theorem. Then the empirical correlation is derived from the data available from theory as well as experimental and numerical results.