Abstract: The invention relates to a hydraulic mineral composition which is characterized in that it comprises a vitreous or crystallised matrix based on magnesium and calcium silico-aluminates which represent at least 25 wt.-%, and preferably 30 wt.-%, of the composition, one or more mineral oxides and optionally one or more specific mineral halides which are selected from among the oxides and halides of Ti, V, Cr, Mn, Co, Ni, Cu, Pb, Ba, Sr, P, S, Na, K, Zr, Mo, Be, Tl, As, Sn and Cd and which represent at least 5 wt.-% of the composition, at most 31 wt.-% alumina (Al2O3), less than 10 wt.-% ferrite, and less than 0.05 wt.-%, and preferably less than 0.01 wt.-%, C in relation to the weight of the composition.

Abstract: A low cost steel desulphurating agent includes, compared with the total weight of the agent, at least 10% of SiO2, at least 10% of C2S, and at least 35% of at least one of calcium aluminate or calcium silico-aluminate. The desulphurating agent can include, compared with the total weight of the agent, the following mineralogical phases: 10 to 60% of C2S, 0 to 50% of C3A, 0 to 50% of C2AS, 0to 70% of C12A7, and 0 to 60% of CA.

Abstract: The invention relates to a steel desulphurating agent characterised in that it comprises compared with the total weight of the agent: at least 10% of SiO2, at least 10% of C2S, at least 35% of at least one calcium aluminate and optionally a calcium silico-aluminate.

Abstract: The invention relates to a steel desulphurating agent, characterised in that it comprises compared with the total weight of the agent: at least 10% of SiO2, at least 10% of C2S, at least 35% of at least one calcium aluminate and optionally a calcium silico-aluminate.

Abstract: The invention relates to a hydraulic mineral composition which is characterised in that it comprises a vitreous or crystallised matrix based on magnesium and calcium silico-aluminates which represent at least 25 wt.-%, and preferably 30 wt.-%, of the composition, one or more mineral oxides and optionally one or more specific mineral halides which are selected from among the oxides and halides of Ti, V, Cr, Mn, Co, Ni, Cu, Pb, Ba, Sr, P, S, Na, K, Zr, Mo, Be, Tl, As, Sn and Cd and which represent at least 5 wt.-% of the composition, at most 31 wt.-% alumina (Al2O3), less than 10 wt.-% ferrite, and less than 0.05 wt.-%, and preferably less than 0.01 wt.-%, C in relation to the weight of the composition.

Abstract: A treatment method includes injecting oxygen into the liquid steel works slag, adding and dissolving in the slag alumina and lime sources, and optionally silica and iron sources and cooling the slag until solidification, the additions being carried out in such amounts and the cooling being performed at such speed that the resulting slag has a mineralogical composition having one of the following constituting element: (a) an amorphous glassy phase; (b) a first group of phases (1) consisting, in weight percentages, of 10–40 CA, 20–50 C2AS, 30–50 C6AF2 and 10–30 C2S; (c) a second group of phases (2) consisting, in weight percentages, of 20–40 C2F, 10–30 C2AS, 20–50 C6AF2 and 10–40 C2S, and (d) a mixture of amorphous glassy phase and of the first or second group of phases. The invention is applicable to hydraulic binders.

Abstract: A method for treating a raw steel plant slag to transform it into a hydraulic binder at least equivalent to a Portland cement clinker, comprises the following steps: oxidizing treatment with input of oxygen, air or a mixture thereof at a pressure ranging between 1 to 15 bars, at a temperature ranging between 1650 and 1400° C., of raw steel slag containing, relative to the raw slag total weight, at least 45 wt. % of CaO and less than 30 wt. % of Fe2O3; and adding to the slag a lime source optionally with silica and/or alumina, so that the slag, after tranformation and at room temperature, has a propotion of Fe2O3 of less than 13 wt. % and a mineralogical composition comprising at least 40 wt. % in C3S mineralogical phase and more than 10 wt. %, of calcium ferrite, relative to the final slag total weight.

Abstract: A process for treating a raw steel industry slag, for converting same into a hydraulic binder at least equivalent to a Portland cement clinker, comprising:

Abstract: The invention concerns a treatment method comprising injection of oxygen into the liquid steel works slag, adding and dissolving in the slag alumina and lime sources, and optionally silica and iron sources and cooling the slag until solidification, the additions being carried out in such amounts and the cooling being performed at such speed that the resulting slag has a miner-alogical composition having one of the following constituting element (a) an amorphous glassy phase; (b) a first group of phases (1) consisting, in weight percentages, of 10-40 CA, 20-50 C2AS, 30-50 C6AF2 and 10-30 C2S; (c) a second group of phases (2) consisting, in weight percentages, of 20-40 C2F, 10-30 C2AS, 20-50 C6AF7 and 10-40 C2S, and (d) a mixture of amorphous glassy phase and of the first or second group of phases. The invention is applicable to hydraulic binders.

Abstract: The invention concerns a process for the treatment of incineration residues of urban or industrial wastes comprising the following steps;a first step of chemical analysis of the incineration residues of urban or industrial wastes in order to determine:their water-soluble sulfate content,the overall retarding or accelerating action of the water-soluble ions which are liable to hinder the setting or hardening of a Portland cement,a second step in which the urban or industrial waste incineration residues are mixed or crushed, with a hydraulic binder and additives, followed by granulation with water of the mixture obtained with the granules then left to harden, the nature and proportion of said hydraulic binder and said additives having been selected in order to allow both the physical and/or chemical neutralization of the harmful elements for setting or hardening of a Portland cement present in the wastes, as well as the production of granules with low porosity and low permeability.