Provided are a Kanbara Reactor (KR) desulfurization stirring paddle casting material and a preparation method therefor. The casting material consists of a base material and an additive; the base material consists of the following raw materials in weight percentages: M70 sintered mullite 60-80%, flint clay 5-20%, fine powder 5-20%, and pure calcium aluminate cement 1-5%. The percentages of each component of the additive based on the weight of the base material are as follows: water reducing agent 0.05-0.2%, and heat-resistant stainless steel fiber 1-5%. The main raw materials are M70 sintered mullite and a small amount of flint clay so as to ensure good thermal shock resistance; the medium temperature and high temperature strength are controlled at 100-180 MPa so as to ensure good erosion resistance; the content of Al.sub.2O.sub.3 in the casting material is 60-70% so as to ensure good corrosion resistance; the ratio of high temperature strength to medium temperature strength is controlled at 1-1.2, which further improves the thermal shock resistance and peeling resistance of the casting material, thereby extending the service life of the stirring paddle. The casting material is lower in cost and has a good practical furnace usage effect; in addition, a paddle blade has less chance of cracking and peeling, while a bottom portion of the stirring paddle is less eroded, thus the frequency of paddle blade repair is low, and service life is significantly improved.

A method for desulfurizing molten steel comprising taking a sample out from molten steel after tapping from a converter or during secondary refining and analyzing the sample rapidly with high accuracy by a method comprising a high frequency induction heating step wherein the sample is combusted and oxidized under the high frequency induction heating in an oxygen atmosphere having an oxygen purity of 99.5 vol % or more to convert S in the sample into SO.sub.2 and an analyzing step wherein SO.sub.2-containing gas produced in the high frequency induction heating step is analyzed through an ultraviolet fluorescence method to quantify S concentration of the sample.

A method for desulfurizing molten steel comprising taking a sample out from molten steel after tapping from a converter or during secondary refining and analyzing the sample rapidly with high accuracy by a method comprising a high frequency induction heating step wherein the sample is combusted and oxidized under the high frequency induction heating in an oxygen atmosphere having an oxygen purity of 99.5 vol % or more to convert S in the sample into SO.sub.2 and an analyzing step wherein SO.sub.2-containing gas produced in the high frequency induction heating step is analyzed through an ultraviolet fluorescence method to quantify S concentration of the sample.

Proposed is a method for removing phosphorus from a phosphorus-containing substance which is applicable in an industrial scale so as to effectively reduce phosphorus contained in the phosphorus-containing substance. In this method, the phosphorus-containing substance used as a raw material for metal smelting or metal refining is reacted with a nitrogen-containing gas at a treatment temperature T ( C.) which is lower than a melting temperature (T.sub.m) of the substance, so that phosphorus is removed preferably in the form of phosphorus nitride (PN). In this regard, a nitrogen partial pressure and an oxygen partial pressure in the nitrogen-containing gas are preferably controlled, thereby reducing a load of dephosphorization process, for example.

When performing dephosphorization treatment of hot metal by adding a refining agent as a lime source and an oxygen source (dephosphorizing agent(s) and a gaseous oxygen source into the hot metal accommodated in a hot metal holding container, the refining agent used is a refining agent having an Ig-loss value of from 4.0% by mass to 35.0% by mass and including 60% by mass or more of quicklime.

Process for dephosphorization of molten metal during a refining process using a lime composition in the form of compacted particles having a Shatter Test Index of less than 20%, leading to a refined metal reduced in phosphorus components to the extent that the refined metal reduced in phosphorus is showing a phosphorus content lower than 0.02 w % based on the total weight of the refined metal reduced in phosphorus.

Process for dephosphorization of molten metal during a refining process using a lime composition in the form of compacted particles having a Shatter Test Index of less than 20%, leading to a refined metal reduced in phosphorus components to the extent that the refined metal reduced in phosphorus is showing a phosphorus content lower than 0.02 w % based on the total weight of the refined metal reduced in phosphorus.

Provided are a Kanbara Reactor (KR) desulfurization stirring paddle casting material and a preparation method therefor. The casting material consists of a base material and an additive; the base material consists of the following raw materials in weight percentages: M70 sintered mullite 60-80%, flint clay 5-20%, fine powder 5-20%, and pure calcium aluminate cement 1-5%. The percentages of each component of the additive based on the weight of the base material are as follows: water reducing agent 0.05-0.2%, and heat-resistant stainless steel fiber 1-5%. The main raw materials are M70 sintered mullite and a small amount of flint clay so as to ensure good thermal shock resistance; the medium temperature and high temperature strength are controlled at 100-180 MPa so as to ensure good erosion resistance; the content of Al.sub.2O.sub.3 in the casting material is 60-70% so as to ensure good corrosion resistance; the ratio of high temperature strength to medium temperature strength is controlled at 1-1.2, which further improves the thermal shock resistance and peeling resistance of the casting material, thereby extending the service life of the stirring paddle. The casting material is lower in cost and has a good practical furnace usage effect; in addition, a paddle blade has less chance of cracking and peeling, while a bottom portion of the stirring paddle is less eroded, thus the frequency of paddle blade repair is low, and service life is significantly improved.

Provided are a Kanbara Reactor (KR) desulfurization stirring paddle casting material and a preparation method therefor. The casting material consists of a base material and an additive; the base material consists of the following raw materials in weight percentages: M70 sintered mullite 60-80%, flint clay 5-20%, fine powder 5-20%, and pure calcium aluminate cement 1-5%. The percentages of each component of the additive based on the weight of the base material are as follows: water reducing agent 0.05-0.2%, and heat-resistant stainless steel fiber 1-5%. The main raw materials are M70 sintered mullite and a small amount of flint clay so as to ensure good thermal shock resistance; the medium temperature and high temperature strength are controlled at 100-180 MPa so as to ensure good erosion resistance; the content of Al.sub.2O.sub.3 in the casting material is 60-70% so as to ensure good corrosion resistance; the ratio of high temperature strength to medium temperature strength is controlled at 1-1.2, which further improves the thermal shock resistance and peeling resistance of the casting material, thereby extending the service life of the stirring paddle. The casting material is lower in cost and has a good practical furnace usage effect; in addition, a paddle blade has less chance of cracking and peeling, while a bottom portion of the stirring paddle is less eroded, thus the frequency of paddle blade repair is low, and service life is significantly improved.

A non-oriented silicon steel and a production method are provided. The non-oriented silicon steel is prepared by using the processes of molten iron desulfurization, converter smelting, RH refining, continuous casting, hot rolling, acid tandem rolling, annealing, coating and finishing, and a chemical composition is as follows in mass percent: C0.003%, S0.008%, Si: 0.35%+1, Mn: 0.15-0.25%, P: 0.04-0.06%, Sn: 0.015%+2, Nb0.004%, V0.004%, Ti0.005%, Mo0.004%, Cr0.03%, Ni0.03%, Cu0.03%, N0.003% and the balance of Fe and inevitable inclusions. The non-oriented silicon steel has the iron loss P.sub.1.5/505.5 W/kg and the magnetic induction intensity B.sub.50001.75 when having the thickness of 0.5 mm, and desulfurization is not needed in the RH refining process.