A process for treating a tailings stream comprising water, solids, and optionally polyacrylamide. The process involves (a) contacting the tailings stream with a silicate source for a pre-determined period of time to form a mixture; b) after a pre-determined period of time of at least 5 minutes, contacting the mixture with an activator to initiate gel formation, wherein the gel entraps the solids within the gel; and c) allowing the gel to strengthen and solidify; wherein the gel formation is delayed compared with a non-delayed process.

Described are stabilized materials and methods and systems for providing said stabilized materials. The system includes a first unit for mixing a first combination that includes a quantity of drill cuttings and a drying agent. The system may include a second unit for mixing the first combination with at least a binder and/or a surface acting agent and providing a second combination. The second combination is formed when the first combination is caused to have a reduced moisture content, transitioning from a first state to a second state. The reduced moisture content in the second state is at least 20% less than the moisture content of the drill cuttings. The first combination in a second state is a stabilized material. The first combination in a second state may be a dried material. The binder and/or a surface acting agent with or without additional additives are not introduced until the first combination is in the second state.

A method for conditioning an acid waste by cementation, wherein the acid waste is chosen among liquids having a pH of no more than 4, semi-liquids having a pH of no more than 4, solids of which the partial or full dissolution in water leads to a solution or suspension having a pH of no more than 4, and mixtures thereof, which method comprises the steps of: a) preparing a cement paste having as components at least: a magnesium phosphate cement and the acid waste, and b) hardening the cement paste thus obtained, and is characterised in that in step a), the cement paste is prepared without subjecting beforehand the acid waste to any treatment consisting in reducing the acidity thereof.

The present disclosure relates to the field of ecological restoration of a coal gangue hill, and in particular, to a solid waste-based porous material, a method for preparing the solid waste-based porous material, and a method of ecological restoration of the coal gangue hill by applying the solid waste-based porous material. A coal-based solid waste restoration material and mycorrhizal solid bacterial agent are mixed to restore the coal gangue hill, the coal-based solid waste restoration material is prepared by mixing coal-based solid waste porous materials, low-rank coal, and waste organic matter and adding a microbial quickly decomposition agent for aerobic fermentation and standing.

A hydraulic binder based on a sulfoaluminate clinker including the mineralogical phases ye'elimite C.sub.4A.sub.3$, mayenite C.sub.12A.sub.7, free lime CaO, and optionally belite C2S, characterized in that, in the clinker, the mineralogical phases are 20% to 50% by weight of ye'elimite C4A3$ phase, 5% to 80% by weight of mayenite C.sub.12A.sub.7 phase, and 1% to 5% by weight of free lime CaO, the weight ratio between the mayenite C.sub.12A.sub.7 and ye'elimite C.sub.4A.sub.3$ phases being between 0.1 and 10. The binder can be used to treat polluted soils, in particular soils with a leachable fraction greater than 0.4% that contains predominantly anions and/or heavy metal cations by mixing the soil with the hydraulic binder, in soil/binder weight proportions of between 1 and 40 parts of binder for 100 parts of soil. It makes it possible to stabilize soils which are polluted or to stabilize soils before dumping.

The present invention relates to a method for treating waste material comprising organic components and low and/or medium level radioactive agents. The method comprises encapsulating the waste material into a matrix, gasifying the waste material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or medium level radioactive agents and combustion residues of the organic components and encapsulating the solid fraction by a geopolymer matrix comprising metakaolin.

The present invention relates to a method for treating waste material comprising organic components and low and/or intermediate level radioactive agents. The method comprises adding material comprising fibers and kaolin to the waste material in order to form a starting material, and gasifying the starting material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or intermediate level radioactive agents, gasification residues of the organic components and metakaolin. The present invention also relates to a use of mate-rial comprising fibers and kaolin.

The current invention concerns a method for preparing a coated particulate waste material, comprising the steps of: (a) providing a particulate waste material with an average particle size of between 0.1 and 5.0 mm, and (b) applying a coating material to said particulate waste material, whereby said coating material comprises at least one polymeric compound.

In a second aspect the present invention discloses a coated waste particle comprising a waste material core, and a coating surrounding said waste material core, whereby said waste material core has a particle size of between 0.1 and 5.0 mm and said coating comprises at least one polymeric compound.

A further aspect concerns a building material, comprising one or more coated waste particles.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.

An agglomerate is provided that can include an aluminosilicate (ash) base material and one or more of a binding agent or leach reduction agent. Each of the agglomerate and binding agent can include no more than about 25 wt. % cement.