Abstract: A molten metal component estimation device including: an input device configured to receive measurement information about a refining facility including measurement results regarding an optical characteristic; a model database that stores model expressions and model parameters, regarding a blowing process reaction, including a model expression and model parameters representing a relation between the oxygen efficiency in decarburization and a carbon concentration in a molten metal in the refining facility; and a processor configured to: estimate component concentrations of the molten metal including the carbon concentration in the molten metal by using the measurement information, the model expressions and the model parameters; estimate the carbon concentration in the molten metal based on the measurement results; and determine the model expression and the model parameters to be used when estimating the component concentrations of the molten metal, based on the estimation result of the carbon concentration in t

Abstract: A converter blowing control method includes: calculating, by heat balance calculation and material balance calculation, an amount of oxygen supplied and an amount of a cooling material or a rising heat material charged to control a temperature and a component concentration of molten steel at end of blowing in a converter to target values; controlling the blowing in the converter based on the calculated amount of oxygen supplied and the calculated amount of a cooling material or a rising heat material charged; estimating a pre-blowing molten iron temperature that is a temperature of molten iron used as a raw material for blowing to be a target of the heat balance calculation, charged into the converter, and is in a state immediately before start of the blowing; and using the estimated pre-blowing molten iron temperature as a charged molten iron temperature in the heat balance calculation.

Abstract: A refining process control device includes: a past similar performance extraction unit configured to extract, from the refining performance database, a performance value of a past refining process in which a refining condition being a refining process condition acquired before the start of the refining process and including a result of an immediately preceding refining process in the refining facility, is similar to a refining process condition as a calculation target and the evaluation value is high; and an operation amount determination unit configured to determine an initial operation amount at the start of a refining process based on the performance value of the past refining process extracted by the past similar performance extraction unit, and determine an operation amount based on a change amount of the initial operation amount after the start of the refining process.

Abstract: A method and system for predicting slopping in a converter occurring during decarburization refining in the converter in which molten steel is produced from a molten pig iron by blowing oxidizing gas to the molten pig iron in the converter from a top blowing lance, or optionally further blowing oxidizing gas or inert gas from a bottom blowing tuyere to perform the decarburization refining of the molten pig iron. The method includes measuring an emission spectrum of a throat combustion flame blowing out from a throat of the converter, calculating emission intensity of the measured emission spectrum at a wavelength in a range of 580 to 620 nm, and predicting the occurrence of the slopping based on a time-series change of the calculated emission intensity.

Abstract: A molten metal component estimation device including: an input device configured to receive measurement information about a refining facility including measurement results regarding an optical characteristic; a model database that stores model expressions and model parameters, regarding a blowing process reaction, including a model expression and model parameters representing a relation between the oxygen efficiency in decarburization and a carbon concentration in a molten metal in the refining facility; and a processor configured to: estimate component concentrations of the molten metal including the carbon concentration in the molten metal by using the measurement information, the model expressions and the model parameters; estimate the carbon concentration in the molten metal based on the measurement results; and determine the model expression and the model parameters to be used when estimating the component concentrations of the molten metal, based on the estimation result of the carbon concentration in t

Abstract: A field effect transistor and a sensor using the field effect transistor is provided. The field effect transistor can be manufactured so as to have uniform properties by simple steps at low costs, and can stably detect, when used as a sensor, a very small amount of analyte with a high sensitivity while the properties are hardly deteriorated. A channel of the field effect transistor is constituted by a single-walled carbon nanotube thin film that is grown, by a chemical vapor deposition method, using particles of a nonmetallic material as growth nuclei, the nonmetallic material containing 500 mass ppm or less metallic impurities that contain a metal and its compounds.