WO2012131241A1 - Powder material including activating glass for cement products - Google Patents

Abstract

The invention relates to a powder material including grains of an activating glass including: at least 20 wt % of SiO₂; more than 20 wt % and less than 50 wt % of an alkaline oxide selected from among Na₂O, Li₂O or K₂O; 0.1 to 60 wt % alkaline-earth oxide selected from among CaO or MgO; and at least one of the following two ingredients a) and b): a) grains of a cement selected from among Portland cement, aluminous cement, sulfo-aluminous cement, and quick-setting cement; and b) grains of a solid inorganic compound, the sum of the silica, alumina, and alkaline-earth oxide contents of which is more than 50 wt % and which contains less than 20 wt % of an alkaline oxide. The activating glass enhances the developmental kinetics of the mechanical properties of the hardened hydrated material made from the hydraulic binder powder material.

Description

 PULVERULENT MATERIAL COMPRISING AN ACTIVATOR GLASS FOR CEMENTITIOUS PRODUCTS

The invention relates to the use of a glass composition, called an activator glass, as an activator of a powdery material of the hydraulic binder type.

Glassy materials or glasses reduced to fine particles may in particular be intended to be partially or totally substituted for cement in the context of the preparation of cementitious products. These glasses are usually classified in the category of "alternative materials to Portland cement" or more commonly "SCM" of the English "supplementary cementitious materials". The production of one tonne of portland cement induces the release of one tonne of CO ₂ into the atmosphere and consumes a lot of energy. Replacing some of the Portland cement with SCM material helps to reduce the environmental impact. By cementitious material is meant a powder composition comprising a Portland cement or a composite cement or an aluminous cement or a sulfoaluminous cement or a prompt cement ("prompt natural cernent" in English). By compound cement (or blended cernent) is meant a pulverulent mixture comprising a portland cement and a portland cement alternative material of the mineral solid compound type such as glass, fly ash or slag or natural or synthetic pozzolana or silica fume, or a calcareous filler (often referred to by those skilled in the art as "calcareous filler" or CaCOs). A cementitious material is a hydraulic binder which makes it possible to manufacture cementitious products such as mortar, ready-mix concrete, concrete, prefabricated elements (like a block or a plate), a repair mortar, a glue tiling, self-leveling screed, floor tiling, plaster or mortar, monolayer plaster, coating plaster.

"SCM" glasses based on silica, alumina, lime (CaO), and generally sodium oxide (the person skilled in the art uses the word "soda" for sodium oxide) are usually the fruit waste recovery type reinforcement fibers or cullet bottles. It is indeed It is not conceivable today to manufacture an SCM glass with conventional glass melting processes, such as those used for the manufacture of building glasses or hollow glass, because the manufacturing and transport costs would be prohibitive. It is therefore conceivable that the recovery of glass waste. These are finely ground (average particle size ranging from 5 to 50 μιτι) to be added to the other raw materials used in the composition of the cementitious material. This glass is not an inert mineral filler since it has hydraulic and possibly pozzolanic properties in the presence of cement or lime, that is to say the ability to harden in the presence of water by chemical reaction under conditions ambient temperatures and pressures. This is why it does not have any composition and generally contains silica (S102), sodium hydroxide (Na2O), alumina (Al2O3), lime (CaO) as major oxides. The sum of these major oxides generally exceeds 90% of the weight of the glass.

 The use of glass waste reinforcing fiber type or cullet bottles poses several problems. This waste must be ground to obtain average particle sizes generally between 5 and 50 μιτι, and further, they must be transported to the place of their mixing with the cementitious material. The reinforcing fiber is very bulky and its transport is necessarily expensive. These problems mean that the costs and the CO2 footprint resulting from the use of these ex-waste glasses remain significant.

 An alternative SCM glass obtained by grinding soda-lime cullet (bottle type) used as a partial substitution of the cement or other binder leads to lower mechanical properties in comparison with that resulting from the grinding of reinforcing fiber waste. The quality of the final construction material is therefore different depending on the origin of the milled SCM glass (bottle cullet or reinforcing fibers).

The submerged combustion melting method described below solves the abovementioned grinding problems. This process makes it easy to obtain a low-cost, low-carbon CO2 glass powder, especially a SCM-type glass. It also makes it possible to obtain a sodium silicate powder (mixture essentially of S102 and Na2O). It also allows you to obtain a glass powder playing, according to the present invention, an activator role. In use, the activator glass causes the rapid increase in pH, which improves the kinetics of development of the final mechanical properties of the cement products. The activator effect is sought in the short term in order to improve the kinetics of the setting of the cementitious material and its mechanical properties in order to make it more resistant to stripping (effect generally sought between 16h and 48h). A good activator glass accelerates the hydration kinetics of the hydraulic binder and increases the heat released by this hydration reaction. There is therefore a good glass activator from the heat flux curve released by the hydraulic binder during its setting. It is sought that the rise of the heat flow is earlier and that the maximum of the curve of the heat flow is higher. In particular, a hardening compound (such as sodium silicate) does not necessarily induce activation since the heat flux generated is not necessarily increased.

 The use of a SCM glass can be advantageous in substitution of the cement from the point of view of the mechanical properties. In particular, certain glass compositions rich in CaO and / or alkali, which can be produced by the submerged combustion process, make it possible to obtain a glass powder which is more reactive than soda-lime glass and thus to produce a cementitious material making it possible to develop a mechanical strength (resistance to compression or bending) at least equivalent to that of Portland cement or composite cement.

 In the present application, there is also described a method of manufacturing a glass comprising its submerged combustion melting leading to a liquid foamy glass, and comprising cooling and powdering thereof.

US6460376 and US7565819 teach how to refine the foamy glass from a submerged burner furnace, by vacuum refining or thin layer, in particular by centrifugation. In WO2008132373, the glass is sent from a submerged burner furnace in the upstream zone of a large conventional furnace with overhead burners or electrodes so as to take advantage of the refining zone downstream of the conventional large furnace. Like other documents describing a submerged burner glass melting, mention may be made of US6883349, US6857999, US7448231, US7428827, US2006105899, US2007212546, US7578988, WO2005075912, US2009176639, US2008256981, US2008145804, US2009235695. WO03045870 teaches the use of a slag as SCM. US2009288830 teaches the development of a SCM glass platinum crucible.

 A melting glass is produced by submerged combustion precisely because this type of combustion produces a foamy glass. Indeed, because of its state of foam, grinding powder glass is made easy or unnecessary. Thus, not only is the refining of the glass subsequent to its melting unnecessary, but it is not desired. The production of glass powder is thus made extremely simple and moreover can easily be installed near the cement products manufacturing workshops. Indeed, a submerged burner furnace is small, self-agitated by the gases generated by the flames produced in the glass, does not require elaborate means of introduction of raw materials, easily digests all types of raw materials and in particular any type of waste. Another advantage: in the use as an ingredient in a cementitious composition, the glass may contain non-ferrous materials without this being considered to be troublesome. Fusion does not have to be absolutely total and perfect. In cementitious application, up to 10% by weight of unfused or crystalline phases can be tolerated in the glass. Generally, an SCM glass contains from 1 to 10% by weight. The rate of unmelted or crystallized compounds is determined by Rietveld analysis (X-ray diffractometry).

 We do not describe here in detail the constitution of a submerged burner oven because for this, it is sufficient to refer to the many documents of the state of the art including US6460376, US7565819 or WO2005 / 075912.

 The process involving submerged combustion melting can be used to make a glass powder of any composition. For example, the glass powder may include

20 to 95% by weight of silica (SiO ₂ )

1 to 50% by weight of sodium hydroxide (Na ₂ O) 0 to 50% by weight of lime (CaO).

0 to 40% by weight of alumina (Al ₂ O ₃ )

 0 to 30% by weight of iron oxide.

 The glass powder thus manufactured can in particular be a SCM-type glass. In such a glass, the weight sum of the silica, alumina and alkaline earth oxide (mainly CaO and / or MgO) contents generally represents at least 55% of its weight.

 SCM glass usually includes:

40 to 80% by weight of silica (SiO ₂ ),

5 to 25% by weight of alumina (Al ₂ O ₃ ),

 10 to 45% by weight of CaO or MgO (sum of the CaO and MgO contents, these oxides may be present alone or as a mixture),

- 1 to 15% by weight of iron oxide (sum of all forms of iron). The SCM glass preferably comprises:

 50 to 70% by weight of silica,

 10 to 20% by weight of alumina,

 15 to 40% by weight of CaO or MgO (sum of the contents of CaO and MgO, these oxides being able to be present alone or as a mixture),

- 2 to 10% by weight of iron oxide.

MTS glass may contain iron oxide, but preferably it contains less than 30% by weight (sum of all forms of iron: Fe2O3, FeO, Fe3O _4). However, if it is desired that the glass powder be as whitest as possible, the iron oxide content is preferably less than 1% by weight.

Such an SCM glass generally has an absolute density greater than or equal to 2.6 g / cm ³ . It generally has an absolute density of less than or equal to 3.1 g / cm ³ .

The SCM glass may contain alkaline oxides such as Na ₂ O or K ₂ O or Li ₂ O. In this case, the sum of all the alkali oxides in this SCM glass is less than 50% by weight and preferably less than 30% by weight, especially less than 20% by weight and even less than 10% by weight.

The "SCM" type glass compositions described above are intended primarily to be part of a cementitious material. We have It has now been discovered that certain glass compositions may act as activators of the cementitious composition (said cementitious composition may also contain in addition an "SCM" type glass). In this case, we speak of "activator" type glass composition. Indeed, the glass if it has a suitable formulation, including a high alkali oxide content, can also act as an activator of a cementitious material.

 The "activator" type of glass has the function of activating the setting of a material of the hydraulic binder type comprising a cement (portland or aluminous or sulfo-aluminous or prompt) partially or totally replaced by an alternating material low in oxide alkali. This alternative material is a totally or partially amorphous or crystalline inorganic solid compound, which may comprise silica, alumina, alkaline earth oxide (generally CaO or MgO) of iron oxide. This alternative material may be a "SCM" type glass powder with the compositions described above, of a slag (an expression common to a person skilled in the art for designating a by-product of the iron and steel industry of blast furnaces). or a fly ash ("fly-ash" in English, a common expression of the art to designate a by-product of the combustion of coal-fired power plants).

 A portland cement comprises a calcium silicate (3CaO.SiO2 and

2CaO.SiO2 being present simultaneously) and a calcium aluminate (3CaO.AI ₂ O ₃ and 4CaO.Al ₂ O ₃ .Fe ₂ O 3 being present simultaneously). A slag has a SiO2 CaO ratio (by weight) <1.5, and the sum of its CaO and S102 content represents more than 45% of its weight.

 Flying ash comes from burning coal in thermal power plants. It is amorphous for at least 20% of its weight. It contains from 40 to 90% by weight of (S102 + Al2O3). It can also contain up to 50% by weight of CaO. There are two types: the so-called "silico-aluminous" containing less than 5% by weight of CaO and the so-called "calcium-calcium" containing more than 10% by weight of CaO.

The invention relates to the powdered material as claimed and comprising grains of an activator glass and at least one of the two ingredients a) and b): a) grains of a cement, b) grains of a mineral solid compound.

 The activator glass may be present in the form of a powder at a level of a few% by weight in the powdery material of the hydraulic binder type, and in contact with water it causes the rapid increase of the pH. This is likely to reduce the setting time and improve the development kinetics of the mechanical properties (especially the compressive strength) of the hardened hydrated material derived from the hydraulic binder (and possibly pozzolanic), especially when it contains, in substitution partial or total cement, a mineral solid compound such as a slag or a type of glass "SCM" or a fly ash or a pozzolan natural or synthetic (metakaolin type).

 The cement (portland or aluminous or sulfo-aluminous or prompt) may be present in this powdery material for example at a rate of 10 to 99% by weight. Cement is usually Portland cement. The less cement there is in the powdery material, the more interest there is in adding activator glass. The inorganic solid compound (alternative material) may for example be present in the powdery material in a proportion of 1 to 95% by weight and especially 20 to 60% by weight.

 The activator glass comprises:

 at least 20% by weight, especially 20 to 90% by weight and preferably 20 to 70% by weight of silica (S1O2),

more than 20% and less than 50% by weight of alkaline oxide selected from Na ₂ O, Li ₂ O or K ₂ O (sum of alkaline oxide content selected from Na ₂ O, Li ₂ O or K ₂ O) ,

 0.1 to 60% by weight of alkaline earth oxide selected from CaO or MgO (sum of CaO and MgO contents).

These conditions on these three constituents are cumulative so that each ingredient should have a content falling in the range which concerns it. The composition thus covers the possible combinations for which each of these three ingredients has a content falling within the given range. Of course, the sum of the percentages of all the components contained in the glass reaches 100% and for example, there is no question that all three ingredients have at the same time the maximum content provided by the range which concerns it. The same reasoning applies to all the compositions described in the present application.

The silica content in this activator glass is at least 20% by weight, especially 20 to 90% by weight and preferably 20 to 70% by weight. The sum of the contents of alkaline oxide (Na ₂ O and / or Li ₂ O and / or K ₂ O) in this activator glass is greater than 20% by weight, or even greater than 25% by weight and goes up to 50% by weight. % in weight. For the alkaline earth oxides, CaO is preferred if one seeks to reduce the hygroscopy of the activator glass. The activator glass preferably comprises more than 1% by weight and preferably more than 5% by weight of CaO or MgO (sum of CaO and MgO contents). The activator glass may comprise more than 10% by weight and even more than 20% by weight of CaO or MgO.

 According to one embodiment, the activator glass may not comprise alumina or comprise little of it (less than 10% and preferably less than 5% and preferably less than 1% by weight). This activator glass without alumina or with little alumina can promote the formation of hydrate of the type xCaO.ySiO2.zH2O cement (also called hydrated calcium silicate or C-S-H).

 According to another embodiment, the activator glass may comprise alumina (at least 10% by weight of alumina). This activator glass containing alumina can promote the formation of hydrate of the type of ettringite cement xCaO.yAI2O3.zSO3.tH2O.

 If the activator glass comprises alumina (at least 10% and preferably 10 to 30% by weight of alumina), then the silica content is preferably 30 to 60% by weight, and the CaO or MgO (sum of the contents of CaO and MgO) is preferably from 20 to 50% by weight and more preferably from 20 to 40% by weight. In this composition, the silica content is at least 30% by weight and can be at least 40% by weight. In this composition, the silica content is at most 60% by weight and is generally at most 50% by weight.

 An activator glass composition may comprise at least 10% by weight of alumina and may in particular comprise:

at least 10% of alumina and in particular 10 to 30% by weight of alumina, 30 to 60% by weight of silica

 20 to 50% by weight of CaO or MgO.

 An activator glass composition may comprise at least 10% by weight of alumina and may in particular comprise:

 at least 10% of alumina and in particular 10 to 60% by weight of alumina and more particularly 10 to 30% by weight of alumina,

 40 to 60% by weight of silica

 20 to 50% by weight of CaO or MgO.

 A preferred activator glass composition comprising alumina comprises:

 10 to 30% by weight of alumina,

 30 to 50% by weight of silica

 20 to 40% by weight of CaO or MgO.

If the activator glass comprises less than 10% by weight of alumina, then the sum of the silica and alkali oxide content selected from Na ₂ O, Li ₂ O or K ₂ O is greater than 50% by weight. In this case, the alumina content may in particular be less than 1% by weight and the CaO or MgO content greater than 10% by weight, or even greater than 20% by weight.

 In these compositions, when the percentage by weight of CaO or MgO is given, it is of course the sum of the percentages by weight of CaO and MgO.

The use of this glass composition as an activator of powder material of the hydraulic binder type is an original use in itself and makes (independently of its manufacturing process) the subject of the present application. As part of this use, this activator glass composition can be made in any type of melting furnace: air burner oven, electric oven or submerged burner furnace. The use of a submerged burner furnace provides the advantage of being able to easily achieve the fragmentation of the glass by adjusting its porosity and the cooling rate. In the case of an electric furnace or air burner furnace melting, the activator glass is obtained with less porosity and larger grinding means must be used. Preferably, the activator glass contains the least possible of unmelted, especially less than 2% by weight of unmelted.

 Thus, the invention relates to a powder material with a hydraulic binder function comprising the activator glass which has just been described. This powder material comprises grains of this activator glass and at least one of the following two ingredients a) and b):

 - a) grains of a portland or aluminous or sulpho-aluminous or prompt cement (which covers the possibility of having at least two cements of this list),

 - b) grains of a solid mineral compound (totally or partially amorphous or crystallized), the sum of its contents of silica, alumina and alkaline earth oxide represents more than 50% of its weight and comprising less than 20 % by weight of alkaline oxide (regardless of the alkaline oxide) (which covers the possibility of having at least two different inorganic solid compounds).

 The two types of ingredients a) and b) (cements listed on the one hand and mineral solid compound on the other hand) may be present alone or as a mixture in the powder material. The powdery material therefore contains at least two different constituents: the activator glass on the one hand and at least one of the two ingredients a) and b) on the other hand. Generally, the powdery material containing the activator glass contains both at least one cement a) and at least one inorganic solid compound b).

 For the case where the powdery material contains Portland cement, this Portland cement can be introduced into the powder material in the form of a composite cement.

The activator glass may be present in the hydraulic binder powder material according to the invention in a proportion of 0.1 to 25% by weight and more generally in a proportion of 0.1 to 10% by weight and even 0.1 to 10% by weight. 5% by weight of the sum of the weight of cement (portland or aluminous or sulfo-aluminous or prompt) and mineral solid compound. The less the cement / mineral solid compound mixture comprises of cement, the more the powdery material should contain activator glass. In particular, in the case where the cement / mineral solid compound mixture comprises less than 5% by weight of cement, then advantageously, the activator glass is present in the powder material in a proportion of at least 15% by weight of the sum of the weight of the cement and the inorganic solid compound.

 The mineral solid compound (SCM) is generally at least one of the following constituents: a glass, a slag, a fly ash. It can also be a silica fume, a metakaolin, a kaolin, a natural or synthetic pozzolana, a rice husk ash, a wollastonite, a dolomite , a talc. Thus, this inorganic solid compound may be an SCM glass whose compositions have been given above and comprising less than 20% by weight of alkaline oxide, or even less than 10% by weight of alkaline oxide. Generally, this mineral solid compound is amorphous at least 70% of its weight, or even at least 90% of its weight. The inorganic solid compound is advantageously in the form of particles with a mean diameter D 50 of less than 50 μιτι, preferably less than 30 μιτι, in particular between 5 and 30 μιτι and more preferably between 5 and 10 m (D 50: diameter for which 50% of the particles by weight have a smaller size), which can be measured by laser granulometry.

 The powdery material is a hydraulic binder (which may be pozzolanic), the D50 of which is advantageously in the form of particles with a mean diameter D50 of less than 50 μιτι, preferably less than 30 μιτι, in particular between 5 and 30 μιτι, and even more preferably between 5 and 10 μιτι.

 Limestone may also be present in the powder material.

The activator glass may be made from sand (silica source), carbonate or alkali sulfate (source of alkaline oxide), limestone. The constituents of the activator glass may also partly come from by-products such as slag, cullet or ash from the combustion of biomass or coal or the combustion of mixtures of coal and waste of various kinds (tires, garbage, biomass, wood, tree stumps soiled by a mineral such as sand). The activator glass may comprise sulfur from alkali sulfate or impurity. Preferably, the activator glass contains less than 1% by weight of sulfur (relative to SO3). Activator glass can be made from inexpensive raw materials, including basalt, clay or feldspar. The activator glass may also comprise 0.1 to 15% by weight of oxide (which covers the possibility that there is one or more) different from the oxides of Si, alkali (all alkaline) and alkaline -terrous (all alkaline earthy). Such an oxide may be alumina, an iron oxide, a titanium oxide. The activator glass may comprise iron oxide but preferably it contains less than 10% by weight.

 Preferably, the activator glass is finely ground to improve its kinetics of dissolution as well as that of the inorganic solid compound. The activator glass is advantageously in the form of particles with a mean diameter D 50 of less than 50 μιτι, preferably less than 30 μιτι, in particular between 5 and 30 μιτι and more preferably between 5 and 10 μιτι, which can be measured by laser granulometry. . The choice of these rather fine particle sizes seems to prevent the problem of the formation of an expansive gel mixture of silica and alkali (in English "alkali silica reaction") which leads to a deterioration of the mechanical properties in the long term, generally beyond 28 days of maturation.

 The invention also relates to a method of manufacturing a hardened hydrated material comprising mixing the powder material comprising the activator glass with water, followed by its shaping and then its maturing.

 The activator glass (such as SCM glass) is intended to be introduced into a hydraulic binder, especially of the cementitious material type.

More generally, a powdery hydraulic binder (to be tempered), in particular of the cementitious material type, may comprise a conventional activator and / or the activator glass type described above. A conventional activator is of the alkali silicate or alkali hydroxide type, that is of the formula ROH, where R is K, Na or Li. Generally, the final powdery hydraulic binder contains between 0.1 and 25% and more generally 0.1 to 5% by weight of activator in total (total weight of all activators including the activator glass according to the invention described above). A process for the preparation of a glass powder of any composition, especially an SCM glass or an activator glass, is now described. This process can also be used to produce a sodium silicate powder. The melting in the submerged burner furnace can be carried out at a temperature sufficient to melt the glass, in particular in the case of an SCM glass at a temperature between 1300 and 1450 ° C. This temperature is compatible with the use of refractory current or refractory cement, inexpensive, for the realization of walls, hearth and vault oven.

The glass leaves the submerged burner furnace in the state of molten glass foam. This liquid glass foam may have an apparent density of between 0.5 and 2 g / cm ³ . No ripening compartment or ripening of any kind is necessary. On the contrary, it is advantageous to keep the glass in this sparkling state, conducive to its grinding or bursting into particles. In particular

 - Or cool the glass so that it keeps this sparkling state leading to a cullet made of porous glass grains to grind it, - or cool it quickly enough to burst into granules or particles under the very effect of this cooling , so that a subsequent grinding might even be rendered useless; this rapid cooling is a true quenching.

 The glass can be cooled fast enough to keep its state of foam, even in the solid state. The grinding of such a porous glass is then particularly easy. It is also possible to cool the glass leaving the immersed burner furnace sufficiently rapidly to burst into granules or even particles. Generally, it is sufficient to make contact between the glass leaving the oven with water at a temperature below 100 ° C, preferably cold water, that is to say at a temperature below 30 ° C and even below 20 ° C. Even if the glass has been manufactured between 1300 and 1450 ° C, it drops very quickly in temperature as soon as it comes out of the oven, so that it touches the water with a temperature above 600 ° C and generally above 700 ° C.

You can splash the glass of cold water (running water, usually between 0 and 30 ° C) to achieve this burst. This cold water can be a simple stream of liquid water. We can also send a fog of water on the liquid glass. We can also proceed by the successive sending of two water currents on the glass: the first is a jet of cold liquid water, leading to the formation of glass granules, the second is a water mist (between 0 and 30 ° C) sent to the newly formed granules, leading to fragmentation of the granules into small particles. The hot glass leads to the vaporization of the water it receives. It is thus possible to find the optimum amount of water leading both to the fragmentation of the glass, but also to the sufficient vaporization of the water, so that the finally obtained glass particles are dry. It is then not necessary to provide an additional drying step. The granulation of the glass may be caused by contacting it with cold water. For example, it is possible to send the glass net leaving the oven in an inclined chute continuously fed with cold water. Generally, a chute of a few meters (1 to 5 meters) is sufficient for a flow of molten glass of the order of 5 liters per minute. The size of the chute may depend on the flow of molten glass. The glass is then collected on a mesh conveyor and a gas (such as air, combustion gases from the submerged burner furnace, etc.) is blown through said conveyor to dry the granules, which are then milled.

 Advantageously, the cooling of the glass is carried out by water contacting the liquid foamy glass leading to the spontaneous formation of solid glass granules. Advantageously, the contact between the glass and the water is carried out with the glass at more than 600 ° C, or even more than 700 ° C and with water at less than 100 ° C and preferably less than 30 ° C.

 A device for manufacturing a glass powder (activator or SCM or other composition) may comprise a submerged combustion furnace and a glass cooling unit by contact with water, usually liquid water or a mist of water. This device may comprise a grinding unit. The powder transformation of the glass may therefore comprise grinding.

When the hot frothed glass leaving the oven is subjected to water at less than 30 ° C, it breaks spontaneously into a set of granules. The diameter of more than 50% by number of these granules is generally between 0.1 and 10 mm. More generally, the diameter of more than 70% in number these granules are generally between 0.3 and 5 mm. By diameter is meant that of the smallest sphere that can contain the granule. These granules are porous. The actual density of these granules is between 60% and 95% of the absolute density of the glass. By real density, we mean the ratio between the mass of material and the actual volume of the grains (sum of the elementary volumes of the grains including the volume of closed pores but not open pores). The absolute density of a material is the density of this material, after deduction of all the voids, both voids between the grains and voids inside the grains (totally compact material without any porosity).

 These granules consist essentially of glass, a homogeneous vitreous material passing entirely through it, apart from the possible infertile elements which are included therein. These unfused ones generally have a composition different from the vitreous material constituting the bulk of the granule. This vitreous material constitutes a continuum of material passing right through the granule, which means that at least 90% of the solid surface of the granule consists of this homogeneous vitreous material. It is possible to go from any point on the surface (solid) of the granule constituted by this vitreous material to any other point on the surface (solid) of the granule of this vitreous material without crossing any interface. It is thus possible to have a glass granule of which at least 90% of the mass is homogeneous in composition and forms a vitreous mass continuum that reaches more than 90% of the solid surface of the granule, said granule being of real density of between 60%. and 95% of the absolute density of the glass and whose diameter is between 0.1 and 10 mm.

 A set of granules may contain 1 to 10% by weight of unfused.

In the case of an SCM glass, the glass of the granule may especially comprise 40 to 80% by weight of silica, 5 to 25% by weight of alumina, 10 to 45% by weight of CaO or MgO, 1 to 15% by weight of iron oxide.

 Depending on the fineness of the desired glass particles, the process for preparing a glass powder described above may comprise milling.

SCM glass is finally advantageously in the form of particles of average diameter D50 between 5 and 80 μιτι (D50: diameter for which 50% of the particles by weight have a smaller size), which can be measured by laser granulometry.

 Glass, activator or SCM, can be made from the usual raw materials for the manufacture of a glass. Silica, alumina and CaO very often enter the composition of glasses. They are usually available and used in powder form. Amorphous raw materials such as basalt can be used to reduce melting enthalpy and loss on ignition. The raw materials can at least partly be introduced below the level of the molten glass in the furnace by a worm. We can also get rid of waste by charging in the submerged burner oven, so of course that is taken into account for the calculation of the final composition. The waste can partly enter into the composition of the final glass. Waste can also be used as a source of energy. Waste can also have both of these functions.

The submerged burner furnace can be supplied with very different types of energy, which is one of the aspects of its great flexibility. This oven generally comprises at least one submerged burner fed with a gaseous oxidant and a fuel (in particular liquid fuel or combustible gas). The fuel may be hydrocarbon gas, hydrogen or liquid fuel or an alternative energy. In particular, the submerged burner furnace can be used for the recovery of very diverse organic waste, this waste serving as a fuel for submerged combustion: because of the convective mixing inherent in the technology of submerged combustion, this waste is continuously renewed to near immersed burners until complete combustion. This makes it possible to reduce or even completely stop the supply of gas or liquid fuel to the burners, with a substantial energy gain. The degradation of the organic molecules can thus be complete, until decomposition into carbon dioxide and water. Any combustion ash is trapped in the liquid / foamy phase. This organic waste can therefore provide part or most or most or all the fuel required for submerged combustion. It is therefore possible to use directly in the reactor the power combustible waste, whatever the level of it. The use of organic waste makes it possible to obtain a particularly economical process.

 Organic waste may be of a biological nature (biomass) or may come from the agri-food industry. It may be animal meal that is no longer consumable in at least a portion of European countries, and therefore must be destroyed. It may be wood waste, paper from the paper industry. They may also consist of organic polymers, for example polyethylene, tire residues. In particular, it may be tree strains polluted with sand after grinding.

 Organic waste may be accompanied by waste of a mineral nature which is then part of the vitrifiable materials. It may in particular be glass / plastic composites or sand polluted by hydrocarbons (as a consequence of an oil spill for example). Laminated glazings, for example, associating at least one glass with at least one thermoplastic or non-thermoplastic polymer film, of the polyvinyl butyral (PVB) type, ethylene-vinyl acetate (EVA), polyurethane (PU) or polyethylene terephthalate copolymer ( FART). Mention may also be made of composite materials based on polymer reinforced with glass yarn (or carbon thread or other type of reinforcing thread), used in the automobile industry, or in boats, for example. It is also possible to mention glass / metal composites such as glazings equipped with connectors and metallic coatings. In the latter case, it is very advantageous to oxidize the various metals (in particular silver) accompanying these glazings in the furnace by varying the more or less oxidizing nature of the flame of the submerged burner. Organic waste can be responsible for up to 100% (eg 5 to 50% or 5 to 20%) of the total submerged combustion energy generated in the furnace.

The immersed burner furnace can be operated with a high specific can be drawn more than 5 t / d / m ² and even higher than 10 t / d / m ² and even higher than 20 t / d / m ^2.

A powdered cementitious material, in particular according to the invention, can be produced by a process comprising the manufacture of a glass powder as described previously in a submerged combustion furnace, then mixing the glass powder with a Portland cement powder or aluminous or sulfo-aluminous or prompt and where appropriate an industrial by-product such as slag powder or fly ash or other. The manufacture of the cement powder can be carried out in a manner known to those skilled in the art.

 The glass powder (in particular SCM type and / or activator), the cement powder (Portland or aluminous or sulfo-aluminous or prompt) and the mixture of these two powders can be produced on the same industrial site. In particular, the manufacture of a glass powder, the manufacture of a cement powder and their mixing can be carried out in installations that can be contained in a circle of diameter equal to 100 km.

 A cementitious material can be made by mixing cement

(Portland or aluminous or sulfoaluminous or prompt) with a slag powder. This is usually a by-product slag from the iron and steel industry. The slag has a SiO2 CaO ratio (by weight) <1. This slag is generally ground in a disconnected manner from steel making, on the same site or at a different site. The granulometry of the slag is advantageously close to that of the cement. Depending on the economic situation, it may happen that the iron and steel industry is slowed, in which case slag production is also slowed down. It can advantageously be provided to manufacture SCM glass by the process involving immersed combustion as already described, in particular having a SiO 2 CaO ratio (by weight)> 1, to overcome the cyclical lack of slag. Thus, it is possible to produce a powder containing glass grains having a SiO 2 CaO (weight) ratio> 1 and slag grains having a SiO 2 CaO ratio (by weight) <1. In particular, the manufacture of the glass powder and the preparation of the slag powder can be carried out in facilities that can be contained in a circle of diameter equal to 100 km. The mixing of the slag powder with the glass powder can be carried out on the same industrial site or on another industrial site, in particular that of a cement producer, or that of a producer of cement products. Finally, the glass powder, the slag powder and the cement powder are mixed together and constitute the hydraulic binder.

In use, the powdery hydraulic binder, especially of the cementitious material type is mixed with water and shaped (molded or coated). It then acquires its mechanical resistance by ripening, where appropriate through a cure, to form a hardened hydrated material.

 Examples 1 and 2 illustrate the preparation of SCM glass by submerged combustion melting. Example 3 describes the preparation of an SCM glass from bottle glass. Examples 6 and 10 illustrate the production of a powdery material according to the invention comprising an activator glass.

EXAMPLE 1

In a furnace consisting of a square surface tank of 1 m ² (glass covered hearth surface) equipped with three submerged burners with a maximum power of 300 kW each, the vitrifiable mixture is baked, the composition of which was as follows:

 The temperature of the molten glass was 1400 ° C. The oven draw was 20 t / d. The specific consumption was 1 kWh per kg of glass produced.

The glass from the oven is white and sparkling. It is poured into a stainless steel channel in which cooling water flows (running water at about 8 ° C) to cool the molten glass from 1400 ° C to a few tens of ° C for a distance of about 2 m from chute. The spontaneous fragmentation into granules of the frozen glass foam is observed. The granules had a diameter of about 1 mm on average.

 The glass is then milled using conventional ball mills as used in the cement industry to obtain a glass powder whose particle size distribution has a d50 of 15 μιτι.

 This glass powder is mixed with Portland cement at a rate of 70% by weight of cement and 30% by weight of glass. A mixture of this mixture is prepared and specimens are made. After a course of 28 days, a compressive strength of 56 +/- 1 MPa is measured.

EXAMPLE 2

The procedure is as for Example 1 except that the furnace is composed of two identical tanks in series interconnected by a groove, each tank having a square area of 1 m ² and being equipped with three submerged burners with a maximum power of 300kW each (not fully used). To the vitrifiable mixture, wood aggregates are added at a rate of 11% by weight of all the raw materials charged (including wood). This biomass contributed 300 kW, or 50% of the total energy consumed. The glass foam appears light brown. After a course of 28 days, a compressive strength of 56 +/- 1 MPa is measured.

EXAMPLE 3

 30 kg of soda-lime glass powder containing only 2% of alumina (crushed bottle glass by grinders) and comprising 13% of Na 2 O are mixed with 70 kg of Portland cement. A mixed batch in water is prepared from this mixture and test tubes are made. After a course of 28 days, a compressive strength of 41 +/- 1 MPa is measured.

EXAMPLES 4 - 6

30 kg of soda-lime glass powder (crushed bottle glass by grinders) are mixed with 70 kg of Portland cement. The glass had the composition: 71% silica, 2% alumina, 10% CaO, 2% MgO, 12% of Na2O, 1% K ₂ O, 1% Fe2O3. This glass is a mineral solid compound the sum of its contents of silica, alumina and alkaline earth oxide represents more than 50% of its weight and comprising less than 20% by weight of alkaline oxide.

 To this mixture is added a glass additive whose chemical composition, free of alumina, is indicated in the table below. The additive of Example 6 is an activator glass within the meaning of the present invention. This table also gives the proportion of additive glass in the final powder material as a percentage of the sum of the weight of portland cement and mineral solid compound:

A batch (mixed batch in water) of this mixture is prepared with 40 kg of water and it is followed by isothermal calorimetry heating due to the exothermic reaction of the mixture. The greater the kinetics of the reaction and the heat generated, the more the material is activated. A good activator glass accelerates the hydration kinetics of the hydraulic binder and increases the heat released by this hydration reaction. There is therefore a good glass activator from the heat flux curve released by the hydraulic binder during its setting. It is sought that the rise of the heat flow is earlier and that the maximum of the curve of the heat flow is higher. As a result, hydrates in larger amounts are formed, which leads to a higher mechanical strength (especially in compression). Figure 1 shows the calorimetry curves in time function according to the examples. It can be seen that the pulverulent composition of Example 6 containing additive glass rich in calcium oxide generates a faster reaction kinetics and a greater heat flow. The additive glass of this example 6 is an activator glass within the meaning of the invention.

EXAMPLES 7-9

 Portland cement is mixed with 0% (ex 7), 1, 5% (ex 8) or 4% (ex 9) by weight of a powdered glass (the given percentage is that relative to the weight of cement) of following composition:

 SiO2: 71% by weight

 AI2O3: 1, 7% by weight

 CaO: 10.3% by weight

 MgO: 2% by weight

 Na2O: 12.8% by weight

 K2O: 0.7% by weight

 Fe2O3: 0.5% by weight

 A mixture of this mixture is prepared with water at a rate of 40% by weight of the weight of cement. It is followed by isothermal calorimetry heating due to the exothermic reaction of the mixture. The same heat is found for these three compositions. Glass is therefore not activator.

EXAMPLES 10

 Portland cement is mixed with 4% by weight of a powdered glass (4% by weight of cement) of the following composition:

 SiO2: 52% by weight

 AI2O3: <0.1% by weight

 CaO: 12% by weight

 MgO: <0.1% by weight

 Na2O: 35% by weight

 K2O: <0.1% by weight

 Fe2O3: <0.1% by weight

A mixture of this mixture is prepared with water at a rate of 40% by weight of the weight of cement. It is followed by isothermal calorimetry heating due the exothermic reaction of the mixture. The results, compared with Example 7 (0% glass), are visible in FIG. 2. It can be seen that the glass has indeed activated the setting of the mixture since the rise in the heat flow released is earlier and the maximum of the heat flow curve is higher.

Claims

 1. Powdered material comprising  grains of an activator glass comprising  at least 20% by weight of S102, more than 20% and less than 50% by weight of alkaline oxide selected from Na ₂ O, Li ₂ O or K ₂ O,  0.1 to 60% by weight of alkaline earth oxide selected from CaO or MgO,  and at least one of the following two ingredients a) and b):  a) grains of a cement selected from portland cement, aluminous cement, sulfo-aluminous cement, prompt cement,  - b) grains of a mineral solid compound whose sum of its contents of silica, alumina and alkaline earth oxide represents more than 50% of its weight and comprising less than 20% by weight of alkaline oxide .  2. Material according to the preceding claim, characterized in that it comprises grains of the cement and grains of the inorganic solid compound.  3. Material according to one of the preceding claims, characterized in that the inorganic solid compound is a glass or a slag or a fly ash.  4. Material according to one of the preceding claims, characterized in that it comprises 20 to 70% by weight of silica.  5. Material according to one of the preceding claims, characterized in that the activator glass comprises more than 1% and preferably more than 5% by weight of CaO or MgO.  6. Material according to the preceding claim, characterized in that the activator glass comprises more than 10% by weight of CaO or MgO. 7. Material according to one of the preceding claims, characterized in that the activator glass comprises at least 10% by weight of alumina, 30 to 60% by weight of silica, 20 to 50% by weight of CaO or MgO. 8. 9. Material according to the preceding claim, characterized in that the activator glass comprises 10 to 30% by weight of alumina, 30 to 50% by weight of silica, 20 to 40% by weight of CaO or MgO. 10. Material according to one of claims 1 to 6, characterized in that the activator glass comprises less than 10% of alumina, the sum of the silica and alkali oxide content selected from Na ₂ O, Li ₂ O or K ₂ O being greater than 50% by weight.  1 1. Material according to the preceding claim, characterized in that the activator glass comprises less than 1% by weight of alumina and more than 10% or even more than 20% by weight of CaO or MgO.  12. Material according to one of the preceding claims, characterized in that the activator glass is present in a proportion of 0.1 to 25% by weight of the sum of the weight of the cement and the inorganic solid compound.  13. Material according to the preceding claim, characterized in that the activator glass is present in a proportion of 0.1 to 5% by weight of the sum of the weight of the cement and the inorganic solid compound.  14. Material according to one of the preceding claims, characterized in that the cement is present in a proportion of 10 to 99% by weight.  15. Material according to one of the preceding claims, characterized in that the inorganic solid compound is present in a proportion of 1 to 95% by weight.  16. Material according to the preceding claim, characterized in that the inorganic solid compound is present in a proportion of 20 to 60% by weight. 17. Material according to one of the preceding claims, characterized in that the inorganic solid compound is amorphous at least 70% of its weight, or at least 90% of its weight.  18. Material according to one of the preceding claims, characterized in that the activator glass is in the form of particles of average diameter D50 less than 50 μιτι, preferably less than 30 μηη. 19. Material according to the preceding claim, characterized in that the activator glass is in the form of particles of average diameter D50 between 5 and 30 μιτι. 20. Material according to the preceding claim, characterized in that the activator glass is in the form of particles of average diameter D50 between 5 and 10 μιτι.  21. Material according to one of the preceding claims, characterized in that the inorganic solid compound has an average particle diameter D50 of less than 50 μιτι, preferably less than 30 μιτι. 22. Material according to one of the preceding claims, characterized in that the powder material has an average particle diameter D50 less than 50 μιτι, preferably less than 30 μιτι. 23. Material according to one of the preceding claims, characterized in that it comprises a Portland cement. 24. A method of manufacturing a hardened hydrated material comprising mixing with water the material of one of the preceding claims, followed by its shaping and then its ripening.