High Belite-Containing Sulfoaluminous Clinker, Method for the Production and the Use Thereof for Preparing Hydraulic Binders

Abstract

The present invention concerns a belite-rich sulphoaluminous clinker, a method for producing such a clinker and its use for preparing hydraulic binders, and comprising as a mineralogical formulation: 5 to 25%, preferably 10 to 20%, of a calcium aluminoferrite phase with a formulation corresponding to the general formula C2AXF(1−X), with X comprised between 0.2 and 0.8. 15 to 35%, preferably 20 to 30%, of a calcium sulphoaluminate phase “yee' limit” (C4A3$), 40 to 75%, preferably 45 to 65% belite (C2S), from 0.01 to 10% of one or several minor phases selected from calcium sulphates, alkaline sulphates, perovskite, calcium aluminates, gehlenite, free limestone and periclase, and/or a vitreous phase, and at least one or several secondary elements selected from sulphur, magnesium, sodium, potassium, boron, phosphorus, zinc, manganese, titanium, fluorine, chlorine, the total content of these secondary elements being less than or equal to 15%.

1 . A sulphoaluminous clinker, characterised in that it contains as phase formulation, compared with the total weight of clinker: 5 to 25%, preferably 10 to 20%, of a calcium aluminoferrite phase with a formulation corresponding to the general formula C2AXF(1−X), with X comprised between 0.2 and 0.8. 
 15 to 35%, preferably 20 to 30%, of a calcium sulphoaluminate phase “yee' limit” (C4A3$),    40 to 75%, preferably 45 to 65% belite (C2S), 
 from 0.01 to 10% of one or several minor phases selected from calcium sulphates, alkaline sulphates, perovskite, calcium aluminates, gehlenite, free limestone and periclase, and/or a vitreous phase,  
 and in that it contains one or several secondary elements selected from sulphur, magnesium, sodium, potassium, boron, phosphorus, zinc, manganese, titanium, fluorine, chlorine, present in the following quantities:  
 from 3 to 10% of sulphur expressed in sulphuric anhydride,  
 up to 5% of magnesium expressed in magnesium oxide,  
 up to 5% of sodium expressed in sodium oxide,  
 up to 5% of potassium expressed in potassium oxide,  
 up to 3% of boron, expressed in boron oxide,  
 up to 7% of phosphorus expressed in phosphoric anhydride,  
 up to 5% of zinc, manganese, titanium or mixtures of these, expressed in oxides of these elements,  
 up to 3% of fluoride, chloride, or mixtures of these, expressed in calcium fluoride and calcium chloride, the total content of said additives being less than or equal to 15%.  
   
     
     
         2 . A sulphoaluminous clinker according to  claim 1 , characterised in that it comprises one or several secondary elements in the following quantities, by weight compared to the total weight of the clinker: 
 from 4 to 8% of sulphur expressed in sulphuric anhydride,    from 1 to 4% of magnesium, expressed in magnesium oxide,    from 0.1 to 2% of sodium, expressed in sodium oxide,    from 0.1 to 2% of potassium, expressed in potassium oxide,    up to 2% of boron, expressed in boron oxide,    up to 4% of phosphorus expressed in phosphoric anhydride,    up to 3% of zinc, manganese, titanium or mixtures of these, expressed in oxides of these elements,    up to 1% of fluoride, chloride, or mixtures of these, expressed in calcium fluoride and calcium chloride.    
     
     
         3 . A sulphoaluminous clinker according to  claim 1 , characterised in that it comprises the following secondary elements, in the following quantities, by weight compared to the total weight of the clinker: 
 from 0.2 to 1% of sodium, expressed in sodium oxide,    from 0.2 to 1% of potassium, expressed in potassium oxide,    from 0.2 to 2% of boron, expressed in boron oxide    a fluorine plus chlorine content less than or equal to 1%, expressed in calcium fluoride and chloride.    
     
     
         4 . A sulphoaluminous clinker according to  claim 1 , characterised in that it comprises at least the following main oxides present in the relative proportions expressed in % of the total weight of the clinker: 
 CaO: 50 to 61%    Al 2 O 3 : 9 to 22%    SiO 2 : 15 to 25%    Fe 2 O 3 : 3 to 11%    
     
     
         5 . A sulphoaluminous clinker according to  claim 1 , characterised in that the belite phase of the clinker is partially or totally crystallised in the α′ form.  
     
     
         6 . A sulphoaluminous clinker according to  claim 1 , characterised in that the belite phase of the clinker in the α′ form accounts for at least 50% by weight of the clinker.  
     
     
         7 . A sulphoaluminous clinker according to  claim 1 , characterized in that it comprises an accelerator or retarder of setting and/or hardening.  
     
     
         8 . A production method of a clinker according to  claim 1 , characterised in that it comprises: 
 a) the preparation of a raw mix comprising at least one raw material or a mixture of raw materials able by clinkerisation to provide the phases C2AXF(1−X), with X comprised between 0.2 and 0.8, C4A3$ and C2S in the required proportions;    b) adding to and mixing into the raw mix at least one additive supplying a secondary element selected from sulphur, magnesium, sodium, potassium, boron, phosphorus, zinc, manganese, titanium, fluorine, chlorine, or mixtures of these, in quantities calculated to provide a clinker according to any one of  claims 1  to  4 ;    c) calcinating the mixture at a temperature of 1150° C. to 1350° C., preferably from 1220° C. to 1320° C., for at least 15 minutes in an atmosphere that is sufficiently oxidising to avoid the calcium sulphate being reduced to sulphur dioxide.    
     
     
         9 . A production method for a sulphoaluminous clinker according to  claim 8 , characterised in that the raw materials used in the production are selected from among phosphate limestone, magnesium limestone, clays, fly ash, hearth ash, fluidised bed ash, laterite, bauxite, red mud, slag, clinker, gypsum, desulphogypsum, phosphogypsum, desulphurisation mud, industrial slag, and mixtures of these.  
     
     
         10 . A production method of a clinker according to  claim 8 , characterised in that the clinker obtained is then ground with or without calcium sulphate, in the form of gypsum, or hemihydrate, or anhydrite, until a Blaine specific surface of over 3000 cm 2 /g is obtained, advantageously over 3500 cm 2 /g.  
     
     
         11 . A hydraulic binder comprising a mixture of clinker according to  claim 1  and source materials of calcium sulphate and/or calcium oxide.  
     
     
         12 . A binder according to  claim 11  characterised in that it contains as much as 30% by weight of the total weight of the binder, of at least one material selected from limestone, pozzolana, fly ash and blast furnace slag.  
     
     
         13 . A binder according to claims  11 , characterised in that it contains as much as 15% by weight of the total weight of the binder, of a material selected from gypsum, anhydrites and hemihydrates.  
     
     
         14 . A binder according to  claim 11 , characterised in that it contains at least one setting retarder selected from among gluconates, saccharides, retarders of the phosphoric acid or carboxylic acid type or mixtures of these.  
     
     
         15 . A binder according to  claim 11 , characterised in that it contains at least one dispersing agent selected from polynaphthalene sulphonates, polymelamine sulphonates, hydroxycarboxylic acids, (poly)acrylic acids, their derivatives and their corresponding salts, derivatives of phosphonic acid, and mixtures of these.  
     
     
         16 . A binder according to  claim 11 , characterised in that it is used to produce a slurry, mortar or cement.