Desulfurization Agent Containing Bitumen, Method for the Production Thereof, and Use Thereof

Abstract

An agent for desulfurizing and/or for pre-desulfurizing, in particular for desulfurizing and/or pre-desulfurizing molten pig iron or molten steel, contains calcium oxide and bitumen.

1 - 23 . (canceled) 
     
     
         24 . An agent for desulfurizing and/or pre-desulfurizing which contains calcium oxide, bitumen as well as between 0.01 and 10% by weight of at least one flux agent, wherein the at least one flux agent is selected from the group of members consisting of multivalent alcohols, bituminous coal, silicone oils and mixtures thereof, and wherein the agent does not contain any calcium carbide, any magnesium or any magnesium alloy. 
     
     
         25 . The agent in accordance with  claim 24 , wherein the bitumen is selected from the group of members consisting of road construction bitumen, hard road construction bitumen, soft bitumen, modified bitumen, distillation bitumen, high-vacuum bitumen, polymer-modified bitumen, special bitumen, industrial bitumen, oxidation bitumen, hard bitumen, blended bitumen, cold bitumen, fluxed bitumen, flux bitumen, natural asphalt and any desired mixtures of two or more of the aforesaid compounds. 
     
     
         26 . The agent in accordance with  claim 24  containing 0.1 to 20% by weight of bitumen. 
     
     
         27 . The agent in accordance with  claim 24  further containing a mixture of two or more calcium compounds which contains at least 20% by weight calcium oxide and a remainder to 100% by weight being one or more compounds selected from the group of members consisting of calcium hydroxide, calcium carbonate, and any desired mixtures of the aforesaid compounds. 
     
     
         28 . The agent in accordance with  claim 27 , wherein the mixture of calcium compounds is composed of at least 50% by weight calcium oxide. 
     
     
         29 . The agent in accordance with  claim 27  containing calcium oxide as the only calcium compound. 
     
     
         30 . The agent in accordance with  claim 27 , wherein the calcium oxide is manufactured as soft burnt lime. 
     
     
         31 . An agent in accordance with  claim 27 , wherein the agent has a flowability of at least 40 cm, wherein the flowability is determined in an air channel in that a pneumatic air channel is used which comprises an air box having a gas-permeable fabric, wherein the fabric has a width of 0.1 m and a length of 1.5 m and the fabric is aerated by a fan with a defined volume flow of 20 m 3 /h air from below; a fabric is used having a specific fabric load of 1.6 m 3 /(min*m 2 ), wherein the specific fabric load is understood as the air quantity in m 3  per minute and per m 2  fabric area; the inclination of the conveying channel is set to 2° and then a sample having a weight of 300 g is weighed and is placed at the upper end of the air conveying channel and the outflow length in cm is determined, with the outflow length to be understood as the path length of the material conveyed by the air flow; in this respect, the measurement takes place in the middle of the conveying channel and the conveying channel is then cleaned using an industrial vacuum cleaner and the procedure is repeated successively with four further samples having a weight of 300 g respectively; the respective largest value and the respective smallest value of the values obtained for the outflow length are eliminated and the arithmetic mean of the remaining three values is formed, with this arithmetic mean being the flowability. 
     
     
         32 . The agent in accordance with  claim 24  containing 80 to 99.9% by weight of a mixture of calcium compounds or 80 to 99.9% by weight of calcium oxide as the only calcium compound. 
     
     
         33 . The agent in accordance with  claim 24 , wherein the at least one flux agent is selected from the group of members which consists of glycols, organopolysiloxanes, mixtures thereof, and polymethylhydrogensiloxane. 
     
     
         34 . The agent in accordance with  claim 24  containing between 0.05 to 5% by weight of one or more flux agents. 
     
     
         35 . The agent in accordance with  claim 24  further containing at least one additive. 
     
     
         36 . The agent in accordance with  claim 24  composed of
 i) 0.1 to 20% by weight bitumen; 
 ii) 0.01 to 10% by weight of a flux agent, said flux agent being selected from the group of members consisting of multivalent alcohols, bituminous coals, silicone oils glycols, organopolysiloxanes, any desired mixtures thereof, and polymethylhydrogensiloxane; 
 iii) 0 to 10% by weight of an additive selected from the group consisting of cryolite, sodium borate, fluorite, and any desired mixtures of two or more of the above compounds; and 
 iv) a remainder to 100% by weight being calcium oxide or a mixture which contains at least 20% by weight of calcium oxide and a remainder to 100% being one or more compounds selected from the group of members consisting of calcium hydroxide, calcium carbonate, and any desired mixtures of the aforesaid compounds. 
 
     
     
         37 . The agent in accordance with  claim 24 , wherein at least the calcium oxide contained in the agent has such a distribution of a range of grain sizes that at least 80% by weight of the calcium oxide has a grain size of less than 32 μm. 
     
     
         38 . The agent in accordance with  claim 24  in the form of one or more briquettes, wherein the briquette or briquettes has/have a size (length×width) viewed in cross-section of 10×5 to 200×100 mm. 
     
     
         39 . The agent in accordance with  claim 37  composed of:
 i) 0.1 to 20% by weight of bitumen; 
 ii) 0 to 10% by weight of an additive selected from the group consisting of cryolite, sodium borate, fluorite, and any desired mixtures of two or more of the above compounds; and 
 iii) a remainder to 100% by weight being calcium oxide or a mixture which contains more than 0% by weight of calcium oxide, but at most 99% by weight of calcium oxide and a remainder to 100% being one or more compounds selected from the group of members consisting of calcium hydroxide, calcium carbonate, and any desired mixtures of the aforesaid compounds. 
 
     
     
         40 . A method of manufacturing an agent for desulfurizing, the agent comprising calcium oxide, and bitumen;
 the method comprising the following steps:   a) mixing of i) calcium oxide; ii) bitumen; iii) optionally at least one flux agent; iv) optionally, at least one further additive; as well as v) one or more calcium compounds selected from the group of members consisting of calcium hydroxide, calcium carbonate, and any desired mixtures of the aforesaid compounds; and   b) grinding the mixture obtained in step a) to powder having a distribution of a range of grain sizes in which at least 80% by weight of the powder has a grain size of less than 32 μm.   
     
     
         41 . A method for slag treatment comprising the step of
 adding a desulphurization agent to a melt of at least one of a molten pig iron and a molten steel, said agent containing calcium oxide, bitumen as well as between 0.01 and 10% by weight of at least one flux agent, wherein the at least one flux agent is selected from the group of members consisting of multivalent alcohols, bituminous coal, silicone oils and mixtures thereof, and wherein the agent does not contain any calcium carbide, any magnesium or any magnesium alloy.   
     
     
         42 . A method in accordance with  claim 41 , wherein the agent is introduced into the molten pig iron or into the molten steel by an immersion lance process using a transport gas or by a stirring-in process. 
     
     
         43 . A method in accordance with  claim 41 , wherein the agent is provided in the form of one or more briquettes and is added into the molten pig iron or into the molten steel for pre-sulfurizing and/or for the slag treatment of molten pig iron or of molten steel.