Abstract: The invention relates to a method for producing rock wool and cast iron by melting a mixture of materials such as basalt, blast-furnace slag, coke and components necessary for melting, with an admixture containing alumina, said admixture making it possible to adjust the alumina content in order to obtain a rock wool having the following composition (as wt %): Al2O3: 18-22; SiO2: 40-50; CaO: 10-15; MgO: <10; FeO: <2; Na2O: <4; K2O: <2. The method includes the following operations: producing by melting a slag and a cast iron, separating the slag and the cast iron, and performing a fibring operation on the slag followed by a bonding operation in order to obtain the rock wool. According to the invention, at least one spent adsorbent and/or catalyst is used as an admixture, said catalyst containing alumina in Al2O3 form. Said adsorbent and/or catalyst preferably contains at least one metal, and said metal is retrieved in the cast iron.

Abstract: The present invention refers to a method being easy to recover metals including nickel and aluminum from waste aluminum catalysts, thereby entirely promoting the recovering rate. Said method comprises: preparing and roasting a waste aluminum catalyst with sodium salts, and then obtaining a first solution comprising vanadium and molybdenum, and a dreg comprising nickel and aluminum through leaching and filtrating; collecting and mixing the dreg with alkali powders to obtain a mixture of the dreg and alkali powders, roasting the mixture at 300 to 1000° C. with aluminum in the dreg reacting with hydroxyl generated from the roasting of mixture and further generating aluminum hydroxide, and then obtaining a second solution comprising aluminum and a concentrate having nickel through another leaching and filtrating; and recovering aluminum from the second solution and recovering nickel from the concentrate.

Abstract: A method for recovering rare earth compounds, vanadium and nickel from waste vanadium-nickel catalysts, comprising steps of: acid leaching, by soaking waste vanadium-nickel catalysts into a sulfuric acid solution and obtaining a mixture containing alumina silica slag; sedimentation, by filtering out the alumina silica slag from the mixture to obtain a filtrate, and then adding a salt into the filtrate to precipitate rare earth double salts followed by isolating a sediment of rare earth double salts and a liquid solution via filtration; and extraction, by providing and adding an alkali into the sediment of rare earth double salts followed by further soaking the rare earth double salts in an acid solution to precipitate rare earth oxalate or rare earth carbonate, and adding an oxidizer into the liquid solution to adjust the pH value thereof and then extracting vanadium and nickel from the liquid solution via an ion-exchange resin.

Abstract: A method for recycling metals from waste molybdic catalysts, comprises steps of leaching, by soaking a waste molybdic catalyst into a highly oxidized acid and conducting a reaction between sulfur in the waste molybdic catalyst and the acid to obtain sulfide and vaporizer, wherein metals in the waste molybdic catalyst are dissolved and oxidized by the acid to obtain a first solution and dregs; and refining, by further dissolving metals in the dregs into a second solution, and extracting metals in the waste molybdic catalyst from the first and second solution; wherein, the vaporizer obtained from the step of leaching is converted into highly oxidized acid and recycled in the step of leaching.

Abstract: A method for materials recovery from a catalyst comprising oxides of iron, cerium, molybdenum, and potassium, in which potassium and molybdenum are removed by treating the catalyst with an aqueous leachant, giving an aqueous solution S1 comprising potassium and molybdenum, and a solid residue R1 comprising cerium oxide and iron oxide, and recovering cerium in the form of a solid comprising a cerium(III) compound or cerium(IV) oxide from the solid residue R1.

Abstract: The present invention relates to a process for recovery of nickel and alumina from spent catalyst by direct leaching with sulphuric acid in presence of small amount of an additive. The invention is useful for recovery of both nickel and sources of nickel and therefore important from the view of environmental protection, resource recycling and conservation.