Specialized metallurgical processes – compositions for use therei – Processes – Electrothermic processes
Patent
1996-12-31
1999-03-16
Andrews, Melvyn
Specialized metallurgical processes, compositions for use therei
Processes
Electrothermic processes
75 1063, 75434, 75622, 75623, 106714, 106789, C21B 308, C04B 506
Patent
active
058823751
DESCRIPTION:
BRIEF SUMMARY
This application is the national phase of international application PCT/ AT96/00085 filed Apr. 30, 1996 which designated the U.S.
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a process for the production of hydraulic binders, crude steel and/or alloys, such as, e.g., FeCr or FeV, from basic steel slags containing chromium and/or vanadium.
2. Description of Related Art
For producing cement clinker and special binder qualities having high .alpha.-belite contents and high ultimate strengths from metallurgical slags it has already been proposed to mix together liquid slags from reduction processes and from steelworks processes and, if required, add lime thereto. When mixing acid liquid slags as they incur, for instance, in blast furnace processes and basic steelworks slags as they incur, for instance, in the form of converter slags, heat is released since this is an exothermic neutralization reaction.
As a rule, a relatively high portion of blast furnace slag has been required for the production of hydraulic binders. Besides classical portland cement, such blast furnace slags have gained great importance as slag cements. Slag cements in the narrower sense are finely ground mixtures of gypsum, clinker and blast furnace slag, a slight amount of gypsum usually having been added for controlling the setting time, as is the case with portland cement.
The usability of basic slags as they incur from steelworks processes, for instance as LD slags, in most cases is substantially limited. The disposal of electric arc furnace slags, like that of steel slags, involves relatively high expenditures. At present, steelworks slags and electric arc furnace slags are, for instance, recycled into the blast furnace, the remainder being used in road construction or dumped. However, due to increasing scrap charge quotas, the contents of heavy metals and, in particular, the contents of chromium and vanadium in steel slags and electric arc furnace slags has constantly increased such that simple dumping no longer appears admissible with the concentration of such heavy metals rising. In the future, such slags presumably will have to be dumped on dumping grounds for special waste, the operation of which involves considerable costs.
Steel slag stands out for its relatively high iron oxide content brought about by the refining process. Usual steel slag contains manganese oxide and iron oxide to an extent that may amount up to 33 wt. %. Blast furnace slag stands out for its relatively favorable hydraulic properties. Morever, blast furnace slag has a substantially lower iron oxide content, its processing to basic construction material thus being considerably facilitated.
Binder additives influencing the setting time, the fatigue strength and other parameters essential to binders have gained more and more importance in the production of hydraulic binders. Such additives may be used in connection with conventional hydraulic binders, such as, for instance, slag cement or portland cement, for adjusting the desired properties.
SUMMARY OF THE INVENTION
The invention aims at providing, above all, a further economic way of aftertreating and processing steel slags--dumping of which involves a number of problems--, by which hydraulic binders and crude steel or alloys can be directly obtained from steel slag. The invention, in particular, aims at recovering chromium and vanadium in high purities from basic steel slags without having to carry out cumbersome roasting and leaching processes, while simultaneously being able to quantitatively purify the original chromium- and vanadium-containing slag from metals, such as e.g. manganese so as to obtain an extremely pure slag which in the following may be worked up, for instance, to hydraulically active binders or binder additives. To solve this object, the mode of procedure according to the invention substantially consists in that the liquid steel slag is mixed with an additive selected from the group consisting of blast furnace slag, electric arc furnace slag, dusts from s
REFERENCES:
patent: 2104890 (1938-01-01), Wark
patent: 3579328 (1971-05-01), Svelgen et al.
patent: 5405429 (1995-04-01), Rey et al.
Ullmanns Encyklopadie der technischen Chemie, 4. Auflage, Band 23, Weinheim, Verlag Chemie 1983, Seiten 495 bis 500, insbesondere Kapitel 3.1 4.2. month unavailable.
Edlinger Alfred
Goessnitzer Andreas
"Holderbank" Financiere Glarus AG
Andrews Melvyn
LandOfFree
Process for the production of hydraulic binders and/or alloys, s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for the production of hydraulic binders and/or alloys, s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the production of hydraulic binders and/or alloys, s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-813150