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Societe Chimique Des Charbonnages

Sarp Industries

Cdf Chimie S.a.

Philippe Pichat

Robert Sinn

Jean-Louis Biros

Michel Neil

Bertrand Gontard

Michel Niel

Disclosed is a method for the manufacture of a solid that is practically insoluble in water and non-pollutant. pollutant. This method comprises a step in which there are mixed, in an aqueous medium, at least two compounds in order to obtain a paste. According to this method, one of the compounds or first compound comprises hydrates of alkaline earth oxides and another compound or second compound comprises hydrates of heavy metal oxides; the free water contained in the paste or liquid is present in the liquid in a proportion, in terms of quantities, of 20% to 60% by weight of the total mixture; the solid obtained being substantially without silicates and aluminates. The disclosed method is applicable, in particular, to waste treatment and to the field of civil engineering and construction.

Method for the manufacture of a solid by the mixing of hydrates of

Ash obtained from incineration of municipal waste is mixed with small quantities of water, from 10-35% by weight of the ash, and the product so formed is compacted and extruded. Where required, sufficient lime is added to raise the pH of the product from about 7.4 to about 11.6. The lime can be combined with a product containing silica and/or alumina. The solid products obtained are virtually insoluble in water and are substantially non-polluting.

Treatment of municipal waste ash

Disclosed is a method for obtaining stabilized molded materials from wastes, said method consisting of mixing the waste with a soldification agent and in extrusion molding the material obtained under vacuum and at constant temperature. The corresponding installation has a mixer connected to the molding device.

Method for the obtaining of molded stabilized materials from wastes

The disclosure relates to the field of the storage of toxic wastes, in solidified form, without the creation of any pollution, on appropriate artificial sites. Briefly, a concrete raft is cast on a ground stabilized in depth, said concrete raft being constituted by slabs having joints between them and being arranged in a diamond moulding. This raft can support a tight-sealing material. Wastes are then piled up on the raft in maintaining the shape of a tumulus-like mound, the positioning being done under the protection of a movable cover comprising a travelling crane provided with rolls of plastic film.

Method and installation for the storage of solidified wastes

Smoke purification waste materials (SPW), rich in lime, are mixed with a product containing at least 60% silica and/or aluminum to bring the pH to a value of between 7 and 11.5 and with a quantity of water of between 15% and 160% of the weight of the waste materials and said product. In practice, the ratio of SiO.sub.2 and Al.sub.2 O.sub.3 over CaO must be at least equal to 0.8. Solid compounds are obtained that are virtually insoluble in water and that are non-pollutant.

Process for the insolubilization and aggregation of smoke purification

The process is the type wherein the solid portions of waste materials of all origins are crushed and ground to a granulometry of under 5 mm and then are heated to between 750.degree. C. and 1,350.degree. C. According to the invention, after the addition, if applicable, of liquid waste to obtain a pasty mass, a reagent is added to the latter, in pulverulent form having granules of under 500 microns based with calcium carbonate, silicium oxide and, possibly, aluminum and iron oxides in quantities to produce the following ratio after incineration: ##EQU1## Application to the treatment of all types of waste by combustion.

Waste incineration process

The invention concerns a process for lowering or eliminating the sodium and potassium ion content in various forms of waste. According to the process, waste is treated with the residue, itself regarded as a pollutant since rich in fluosilicic acid, discharged from the manufacture of sulfuric acid on a calcic ore based on calcium phosphate.

Treatment of waste and residue containing sodium and potassium ions

According to the process, a clay material is first dispersed with stirring in the waste (or vice versa) between 0.degree. and 150.degree. C. then, in particular in the case of acidic wastes, it is neutralized to an approximately neutral pH by a product preferably with a lime base and, in a third phase, a hydraulic and/or calcium binder is added to the mixture. Application to petrification of all types of wastes of industrial, mining, urban and other origins.

Process for solidification of strongly acidic or akaline liquid wastes

A process for manufacturing a cellular plaster with plaster obtained by calcining phosphogypsum, comprising mixing dry plaster with a previously prepared aqueous foam and with about 0.1-5% by weight, relative to the dry plaster, of slaked lime.

Process for manufacturing cellular plaster and molded plaster articles

Waste material having a pH not exceeding 2, and which have previously caused a serious disposal problem, are converted into stable, solid, useful, non-polluting products by first mixing the waste material with fly ash using about 30 to 260 parts of weight of ash for 100 parts of waste material, then neutralizing the resultant mixture using lime or calcium carbonate containing materials, next adding a calcium containing binder such as lime or Portland cement, and then solidifying the resultant mixture.

Process for treating liquids wastes possessing a strong acidity

A process for the whitening of phosphogypsum comprising treating a phosphogypsum in aqueous suspension with an amount of ozone equal to at least 150 parts by weight per million parts by weight of phosphogypsum calculated as Ca SO.sub.4.2H.sub.2 O, the pH of the aqueous suspension being lower than or equal to 3, to yield a whiteness grade of phosphogypsum higher than 75, according to French Standard NF Q 03-038.

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Paris, France

Philippe Pichat