Method for Manufacturing Briquettes Containing a Calcium-Magnesium Compound and an Iron-Based Compound, and Briquettes Obtained Thereby
AssigneeS. A. Lhoist Recherche et Developpement
InventorsGuillaume Criniere, Michael Nispel
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Abstract
Composition in the form of green or thermally treated briquettes comprising at least one “quick” calcium-magnesium compound comprising an iron-based compound and method of production thereof as well uses thereof.
Claims39
Method for manufacturing a calcium-magnesium composition in the form of briquettes, comprising the following steps:
- i. supplying a pulverulent mixture comprising at least one “quick” calcium-magnesium compound, said mixture comprising at least 40 wt % of CaO+MgO equivalent relative to the weight of said composition and having a Ca/Mg molar ratio greater than or equal to 1, preferably greater than or equal to 2, more particularly greater than or equal to 3 and an iron-based compound having a very fine granulometric distribution characterized by a median size d50 below 100 μm, preferably below 50 μm as well as a size d90 below 200 μm, preferably below 150 mμm, preferably below 130 μm, more preferably below 100 μm;
- feeding a roller press with said mixture,
- iii. compressing said pulverulent mixture in said roller press, the rollers of the roller press developing linear speeds at the periphery of the rollers between 10 and 100 cm/s, preferably between 20 and 80 cm/s, and linear pressures between 60 and 160 kN/cm, preferably between 80 and 140 kN/cm, and even more preferably between 80 and 120 kN/cm, obtaining a calcium-magnesium composition in the form of green briquettes, and
- iv. collecting said green briquettes,
- wherein said at least one “quick” calcium-magnesium compound comprising at least 40 wt % CaO+MgO equivalent further comprises at least a fraction of particles of calcium-magnesium compound having a particle size ≤90 μm having at least 20 weight % CaO equivalent with respect to the weight of said pulverulent mixture, and wherein said iron-based compound being present at a content of at least 20 wt %, preferably at least 25 wt %, more preferably at least 30 wt %, in particular at least 35 wt % relative to the weight of said composition.
Composition in the form of green briquettes comprising at least one “quick” calcium-magnesium compound and art iron-based compound, characterized in that the composition comprises at least 40 wt % of CaO+MgO equivalent relative to the weight of said composition, said composition having a Ca/Mg molar ratio greater than or equal to 1, preferably greater than or equal to 2, more preferably greater than or equal to 3 and characterized in that said iron-based compound is present at a content of at least 20 wt %, preferably at least 25 wt %, more preferably at least 30 wt %, In a preferred manner at least 35 wt % of Fe2O3 equivalent relative to the weight of said composition, said iron-based compound having a very fine granulometric distribution characterized by a median size d50 below 100 μm, preferably below 50 μm as well as a size d90 below 200 μm, preferably below 150 μm, preferably below 130 μm, more preferably below 100 μm, wherein said at least one “quick” calcium-magnesium compound comprising at least 40 wt % of CaO+MgO equivalent comprises a fraction of particles of calcium-magnesium compound having a particle size ≤90 μm having at least 20 weight % CaO equivalent with respect to the weight of said pulverulent mixture.
Composition in the form of thermally treated briquettes, comprising at least one iron-based compound, said composition comprising at least 40 wt % of CaO+MgO equivalent relative to the weight of said composition and having a Ca/Mg molar ratio greater than or equal to 1, preferably greater than or equal to 2, more preferably greater than or equal to 3, characterized in that said iron-based compound is present at a content of at least 20 wt %, preferably at least 25 wt %, in a preferred manner at least 30 wt %, more preferably at least 35 wt % of Fe2O3 equivalent relative to the weight of said composition, said iron-based compound comprising at least 60% of calcium ferrite, expressed by weight of Fe2O3 equivalent, relative to the total weight of said iron-based compound expressed by weight of Fe2O3 equivalent and wherein at least 20 wt % calcium ferrites with respect to the weight of the composition in the form of thermally treated briquettes, wherein said calcium ferrite forms a matrix wherein “quick” calcium-magnesium compound are dispersed.
39-43. (canceled)
Dependencies are inferred from the claim text.