Process for producing cement from metallurgical slag
Assignee"Holderbank" Financiere Glarus AG
InventorsAlfred Edlinger, Theo Rey
Life of this patent
Estimating the term…
Abstract
In a process for the preparation of cement from metallurgical slags, in which liquid slags from reduction processes and steelworks processes, e.g. blast furnace and converter slag, are mixed together and mixed with lime the procedure is such that in a first cooling phase at temperatures above 1000.degree. C., and preferably above 1200.degree. C., the cooling is slower than in a subsequent second cooling phase and that the solidified product obtained is granulated and/or ground in order to obtain directly cement with improved hydraulic properties, in particular increased final strength.
Claims21
Process for the preparation of cement from metalurgical slags comprising
- mixing together liquid slags from reduction processes and steelworks processes to form a melt, said liquid slags comprising lime, silicic acid and alumina, and said melt having a temperature greater than 1000.degree. C.;
- cooling said melt by carrying out a first cooling phase at temperatures above 1000.degree. C.;
- further cooling said melt by carrying out a second, more rapid cooling phase at temperatures below 1000.degree. C., so that a solidified product is obtained that is granulated and/or ground.
Process for the preparation of cement from metalurgical slags comprising
- mixing together liquid slags from reduction processes and steelworks processes to form a melt, said liquid slags comprising lime, silicic acid and alumina, and said melt having a temperature greater than 1000.degree. C.;
- adding chlorides to said melt;
- cooling said melt by carrying out a first cooling phase at temperatures above 1000.degree. C.;
- further cooling said melt by carrying out a second, more rapid cooling phase at temperatures below 1000.degree. C., so that a solidified product is obtained that is granulated and/or ground.
Process for the preparation of cement from metalugical slags comprising
- mixing together liquid slags from reduction processes and steelworks processes to form a melt, said liquid slags comprising lime, silicic acid and alumina, and said melt having a temperature greater than 1000.degree. C.;
- reducing the viscosity of the melt by the addition of CaF.sub.2 ;
- cooling said melt by carrying out a first cooling phase at temperatures above 1000.degree. C.;
- further cooling said melt by carrying out a second, more rapid cooling phase at temperatures below 1000.degree. C., so that a solidified product is obtained that is granulated and/or ground.
Process for the preparation of cement from metalurgical slags comprising
- mixing together liquid slags from reduction processes and steelworks processes to form a melt, said liquid slags comprising lime, silicic acid and alumina, and said melt having a temperature greater than 1000.degree. C.;
- cooling said melt by carrying out a first cooling phase at temperatures above 1000.degree. C.;
- passing said melt to a fluidized bed or a fluidized bed cascade and cooling with 1.5 to 3.5 Nm.sup.3 /kg clinker cooling air over a period of 15 to 45 minutes so that said melt solidifies to clinker granules having a diameter of less than 4 mm.
Dependencies are inferred from the claim text.