A method for monitoring the wear of a refractory lining of a blast furnace, the method comprising the following steps: a. Modelling in at least two dimensions at least a part of the blast furnace at an initial known state, b. Defining (102A, 102B), the internal and external thermal boundary conditions of the modelized part, c. Calculating the thermal field within said modelized part of the blast furnace considering the refractory lining thermal characteristics and internal and external thermal boundary conditions, said thermal field comprising temperature field and heat path lines (L n), starting point of each path line (L n) being a measurement point (P n) and end being the internal boundary, d. Measuring the temperature T meas_n at each measurement point (P n), e. Based on the thermal field calculation: e1 - Using the measured temperature T meas_n at each measurement point (P n) as starting value, moving a control point (X n) along each heat path line (L n) and determining a position (I n) where said control point (X n) reaches a critical temperature T crit, e2 - Determining the position of the hot metal solidification isotherm, said isotherm being the curve linking all previously determined positions (I n) at which the critical temperature T crit is reached, f. Calculating a new thermal field using the previously determined position of the hot metal solidification isotherm as new internal thermal boundary conditions g. Estimating the temperature T est_n at each measurement point (P n) using the newly calculated thermal field, h. Calculating a convergence criterion CC between each estimated temperatures T est_n and respective measured temperatures T meas_n: - if this convergence criterion CC is below a predefined target Δ, determining a wear surface of the refractory lining based on the position of the hot metal solidification isotherm, - if this convergence criterion CC is above the predefined target Δ, iterating steps e to h until the convergence criterion CC is below the predefined target Δ. a. Modelling in at least two dimensions at least a part of the blast furnace at an initial known state, b. Defining (102A, 102B), the internal and external thermal boundary conditions of the modelized part, c. Calculating the thermal field within said modelized part of the blast furnace considering the refractory lining thermal characteristics and internal and external thermal boundary conditions, said thermal field comprising temperature field and heat path lines (L n), starting point of each path line (L n) being a measurement point (P n) and end being the internal boundary, d. Measuring the temperature T meas_n at each measurement point (P n), e. Based on the thermal field calculation: e1 - Using the measured temperature T meas_n at each measurement point (P n) as starting value, moving a control point (X n) along each heat path line (L n) and determining a position (I n) where said control point (X n) reaches a critical temperature T crit, e2 - Determining the position of the hot metal solidification isotherm, said isotherm being the curve linking all previously determined positions (I n) at which the critical temperature T crit is reached, e1 - Using the measured temperature T meas_n at each measurement point (P n) as starting value, moving a control point (X n) along each heat path line (L n) and determining a position (I n) where said control point (X n) reaches a critical temperature T crit, e2 - Determining the position of the hot metal solidification isotherm, said isotherm being the curve linking all previously determined positions (I n) at which the critical temperature T crit is reached, f. Calculating a new thermal field using the previously determined position of the hot metal solidification isotherm as new internal thermal boundary conditions g. Estimating the temperature T est_n at each measurement point (P n) using the newly calculated thermal field, h. Calculating a convergence criterion CC between each estimated temperatures T est_n and respective measured temperatures T meas_n: - if this convergence criterion CC is below a predefined target Δ, determining a wear surface of the refractory lining based on the position of the hot metal solidification isotherm, - if this convergence criterion CC is above the predefined target Δ, iterating steps e to h until the convergence criterion CC is below the predefined target Δ. - if this convergence criterion CC is below a predefined target Δ, determining a wear surface of the refractory lining based on the position of the hot metal solidification isotherm, - if this convergence criterion CC is above the predefined target Δ, iterating steps e to h until the convergence criterion CC is below the predefined target Δ.