Abstract: The invention relates to a process for the synthesis of a layered, clay-like material starting from a silicon oxide containing material in a finely divided state by reacting a glass phase containing material at a pH from 5 to 8, in the presence of water, with a source of layer-forming metal ions and an activator for the formation of clay under atmospheric conditions to obtain a material with a stable structure. Preferably aluminium and/or magnesium ions are employed as layer-forming metal ions. Furthermore, according to a suitable embodiment, boron glass or cullet is employed as a material containing silicon oxide. The conversion of the mixture of materials into a substance having an ordered structure takes place preferably at a pH of approximately 7 and a temperature of 30.degree.-45.degree. C., in which the starting materials appropriately have a particle size of approximately 100 microns. An activator for the formation of clay is added to accelerate the process of conversion.

Abstract: The invention relates to a porous granulated steel slag having a weight per unit volume of less than 1 kg/dm.sup.3 in the loosely dumped state and of 0.99 kg/dm.sup.3 in the compacted dumped state, having a free calcium oxide content of at most 1/10 of the content in the non-granulated slag. The present steel slags are obtained by spraying a molten stream of steel slag with a sprayed pressurized stream of water. After comminuting, for example by grinding, and removal of iron, the porous granulated steel slag can be separated into a ferrite-richer fraction, which can serve as raw material for steel production, and a lower-ferrite fraction, which can serve as raw material for an inorganic binder. Granulated steel slag is also used as aggregate in building materials, as raw material in road building materials and for embankment materials, and as cement replacement material.

Abstract: A method is described for capturing ecologically harmful substances, both of organic and inorganic nature, by absorbing these substances on a zeolite or on a swellable, layered clay which has been modified with hydroxyaluminium to form an aluminium-rich zeolite or a pillared clay containing pillars of aluminium hydroxide complexes, the aluminium-rich zeolite or aluminium-pillared cationic or anionic clay having been treated, prior to the absorption, with a salt of an inorganic acid, preferably with a phosphate. If the treatment is carried out with a salt of a rare earth element, superpillars are formed in the clay, as a result of which a clay having a great absorbency in addition to a large rate of flow is obtained. By treating the pillared clay with a quaternary ammonium compound, a doubly modified clay is formed which is exceedingly suitable for treating material which has been polluted with a combination of organic and inorganic ecologically harmful substances, and in particular polluted with heavy metals.

Abstract: A method for immobilizing material contaminated with heavy metal ions, a fixant for immobilizing heavy metal ions and a matrix.A method is disclosed for immobilizing material contaminated with heavy metal ions, said metal ions in a liquid environment being allowed to react with a metal-complexing agent with the formation of a metal complex, the metal-complex formed being mixed, in the presence of water, with an inorganic, hydraulic binder comprising blast furnace slag cement, fly ash cement or a combination thereof to form a matrix having reductive properties in the form of a hard, rocklike material, which method is characterized in that said metal complex is formed in the presence of a metal-complex bond activator. Said metal-complex bond activator is preferably a water-soluble salt of a transition metal element, expediently ferric chloride or manganese sulphate.

Abstract: A toxic waste fixant for detoxification of a contaminated material includes a mixture of ferric sulfate, manganese sulfate, organophilic clays, an oxidizer and aluminium sulfate. The respective amounts are preferably about 15-19% b.w. of ferric sulfate, about 15-19% b.w. of manganese sulfate, about 37-46% b.w. of organophilic clay, about 16-19% b.w. of an oxidizer and about 0-12,5% b.w. of alumimium sulfate. All or part of the ingredients in said fixant may be added as a pretreatment into contaminated materials such as soils, sediments, or sludges. This pretreatment can range from 0 to 100% b.w. to said material. The fixant is blended with various amounts of Portland cement, and/or blast furnace slag, or lime, or gypsum, or coal fly ash, or cement kiln dust as a means to derive a chemical fixation treatment for contaminated soils, sediments, and sludges to prevent the leaching of organic and inorganic compounds and elements.

Abstract: The invention relates to a method for preparing a hydraulically settable cement base material starting from steel slags formed in a steel-making process, which method comprises the formation, in steel slags in the liquid state, of a ferrite gradient by adding a ferrite-precipitating compound, the separation, if required, of the high-ferrite fraction formed, the separation of at least the low-ferrite fraction formed, the cooling and the comminution thereof to obtain a hydraulically settable material. The ferrite-precipitating compound used has preferably acid components, and can expediently generate silicic acid. At least before the cooling of the low-ferrite fraction, the aluminum content of the liquid slag material is regulated by the addition of an aluminate-containing material, such as bauxite. The high-ferrite fraction separated can be returned to the steel-making process to reduce or remove the addition of a flux in the production of steel.

Abstract: The invention relates to a cement composition which can be hardened hydraulically and which consists of ground cement clinker material, granulated blast furnace slags and comminuted steel slags. The comminution of the steel slags is preferably carried out by grinding, in particular to a particle size of at most 0.2 mm and expediently to 0.09 mm. The ground steel slags have a Blaine value of at least 400 m.sup.2 /kg, expediently 473 m.sup.2 /kg, and a weight per unit volume of 2,800-4,000 kg/m.sup.3. The steel slags are chosen from air-cooled steel slags, foamed steel slags, granulated steel slags or a combination thereof. A method is also described for the preparation of a cement composition which can be hardened hydraulically, in which method cement clinker material and ground, granulated blast furnace slags are mixed with ground steel slags at normal or elevated temperature and pressure, the obtained mixture is cooled if desired, and comminuted to obtain a hydraulically hardenable cement composition.

Abstract: A fixant for fixing toxic organic compounds comprised in waste material comprising an inorganic binder based on calcium compounds mixed with an alumino silicate, and at least one metal sulphate which fixes said organic compounds and counteracts leaching, is disclosed. Preferably a combination of several metal sulphates, especially aluminum sulphate, manganese sulphate and ferric sulphate is used. Moreover, the fixant preferably comprises an organo-clay compound, in particular a bentonite, a montmorillonite and a hectorite.A process of treating waste material comprising toxic organic compounds by mixing said waste material with said fixant, as well as a matrix formed from at least a set inorganic binder based on a cement and a silicate with environmentally harmful organic compounds containing waste material encapsulated therein, said matrix also comprising at least one metal sulphate which fixes said organic compounds and counteracts leaching is disclosed.

Abstract: The invention relates to a method for fixing toxic or nontoxic waste material, in which method the waste material is allowed to absorb into an organic absorbent, the waste material-containing absorbent thus obtained is treated with an occluding agent and the resulting product is mixed with a hydraulic binder and a hardening activator in order to form a cement matrix. The occluding agent used in preferably a silicon compound, such as silica gel or water glass, or a silicon polymer which can be formed from granulated blast furnace slags. The absorbent used can be an organo-clay compound and/or cellulose. The invention also relates to a composite kit for fixing waste material, comprising an absorbent, a hydraulic binder and an occluding agent.

Abstract: A toxic waste fixant for detoxification of a contaminated soil, sediment, and or sludge material includes a mixture of: ferric and/or ferrous sulfate, manganese sulfate, and/or aluminium sulfate and/or Portland cement, and/or gypsum (calcium sulfate), and/or blast furnace slag, and/or lime (calcium oxide). Fixants made from mixtures of the above compounds are designed to prevent leaching in excess of regulatory standards for specified inorganic and organic toxic compounds and elements. These fixants will also reduce the concentration of most organic toxic compounds through various chemical reactions and bonding as determined by solvent extractions and analysis by GC/MS. The ferric and/or ferrous sulfate may be partially or completely replaced by cobalt sulfate, whereas instead of the respective sulfates the corresponding chlorides may be used as well.

Abstract: The invention relates to a fixing agent, for fixing organic and inorganic impurities containing material, which comprises an organophilic clay material and a clay-growth agent. The clay-growth agent comprises at least one magnesium compound and/or at least one aluminium compound, and an initiator for clay formation. This initiator is a silicon-containing material, such as a glass or a silicon-containing rock, such as pumice, basalt or andasite. The magnesium compound preferably originates from granulated blast furnace slags, or is magnesium oxide, whereas the aluminium compound is expediently aluminium oxide or an alumina containing material. An oxidising agent can also be present. A method for fixing organic and inorganic impurities containing material to an at least partially organophilic clay material in an aqueous medium, and, if desired, hardening the resulting material using an inorganic reagent and, where appropriate, a hardening activator, is also described.

Abstract: A method for rendering toxic waste harmless by mixing water, at least ground, granulated blast furnace slag as reagent and said waste to form a transportable fluid slurry which can be allowed to harden to a hard, rock-like material. The toxic waste appropriately consists of substances which do not react with the reagent. A hardening activator can be added to the slurry at an arbitrary point in time. The solids content of the slurry, based on water-insoluble substances, is preferably at least 50%.

Abstract: A process is disclosed for immobilizing environmentally noxious organic, particularly aromatic, substances by absorbing them on a layered clay mineral modified by exchange with a quaternary ammonium compound, thereby increasing the spacing between the layers and rendering the adsorption surfaces hydrophobic.After adsorption of the organic compounds the spacing between the layers of the layered clay mineral is reduced by a layer spacing reducing agent, and subsequently the clay mineral containing the organic compounds is mixed with a hardenable inorganic binder and the whole is hardened.A typical example of a modifying agent is a quanternary ammonium compound, and of a layer spacing reducing agent an alkaline substance, such as sodium hydroxide.Typical clay minerals are chosen among the smectite minerals, tectosilicates and phyllosilicates; preferably montmorillonite clay is used.The inorganic binder may be a calcium hydroxide compound or a calcium containing cement, preferably containing fly ash.

Abstract: A gas bearing part is provided, having gas supply means which open out into a recessed working surface which can be placed opposite a carrier plate to permit formation of a gas bearing relative to the carrier plate.To obtain a friction-free movement, also with application of higher gas pressures the roughness of the working surface is less than 10 ru, preferably less than 4 ru. The working surface is further essentially conically recessed, whereby the tip of the conical recess is essentially in the centre of the surface.

Abstract: A gas bearing (1) comprising two bearing parts (2, 3) of granite type material and similar natural stone materials and means for injecting a gas between the bearing parts (2, 3) for forming a gap (7, 11) therebetween. The pores (10) in the surfaces of the granite material of these bearing parts are sealed by a non-brittle, transparent, mechanically, machinable pore sealing material (9, 12) for forming gas bearing parts having a non-porous surface. Examples of pore sealing materials (9, 12) for sealing the pores of the bearing parts and bearing part material are polyurethanes, acrylic polymers, epoxy resins, silicone resins, polyvinylidenefluoride resins, aramide resins etc. Preferably the pore sealing material consists of a polymer being curable at low temperatures, particularly below 30.degree.C.

Abstract: A noxious metal(s) containing waste material is treated with an acid solution of a metal of group VIIa or VIII of the Periodical System, preferably iron or manganese. Subsequently, the metal of group VIIa or VIII dissolved in the acid is precipitated as a metal hydroxide and simultaneously the noxious metal(s) dissolved from said waste by said acid solution are incorporated in said precipitating metal hydroxide.The waste material together with precipitated metal hydroxide is subjected to an immobilization treatment.Manganese hydroxide is particularly suitable for removing cadmium.An acid solution of iron and preferably simultaneously manganese to be used for treating the waste is obtained by dissolving oxysludge caught during iron or steel manufacture.The method is particularly for treating dredged harbor sludge.

Abstract: A composition obtained by mixing fly ash, calciumsulphate hemihydrate and oxisludge, a product caught from gases emanating from converters during steel production.Oxisludge containing substantial amounts of iron is used in an amount comprised between 0,2 and 10%, preferably 1 to 5%.The composition is a loose mass or consists of granular products.

Abstract: A moist sludge as obtained from gases evolved during steel preparation in converters by blowing oxygen through said liquid steel is treated with 30% flue dust. Preferably the mixing is effected in two steps, in the first step 60% of the flue dust is added and the particles as obtained are mixed with the remaining flue dust in a second step without crushing the particles of the first step, particularly by using a whirling process.

Abstract: A process for recovering energy from substances having a high temperature, in particular for recovering energy from molten slag material obtained in metallurgical processes, the heat being emitted by said substances by radiation, being recovered in regions, positioned at distance from said substances. In case of liquid substances such as molten slag material, this is conveyed during the recovery of radiation heat.

Abstract: Harmful metals containing particles being emitted in chemical or physical processes, such as in iron production or in combustion processes, are caught and intimately divided in a molten metallurgic slag in order to avoid pollution problems.