Abstract: A nano-silica hybrid vinyl phenyl silicon intermediate, a preparation method therefor and a use thereof in an environmentally-friendly insulating varnish are provided. The nano-silica particles are dispersed uniformly and stably; the nana-silica hybrid vinyl phenyl silicon intermediate has the advantages of resisting high temperatures and coronas and being high in activity; the temperature index measured according to a secant method is 200° C.-240° C., the measured corona-resistant time is 18-36h, and the vinyl active sites carried thereon can have a good compatibility with polyesterimide, heat-resistant polyesters, hydrogen-containing siloxane and modified epoxy; the intermediate is particularly suitable for preparing a high-temperature-resistant and corona-resistant solvent-free insulating varnish; and there are on volatile gases during use, thereby causing on pollution to the atmospheric environment.

Abstract: A nano-silica hybrid vinyl phenyl silicon intermediate, a preparation method therefor and a use thereof in an environmentally-friendly insulating varnish are provided. The nano-silica particles are dispersed uniformly and stably; the nana-silica hybrid vinyl phenyl silicon intermediate has the advantages of resisting high temperatures and coronas and being high in activity; the temperature index measured according to a secant method is 200° C.-240° C., the measured corona-resistant time is 18-36h, and the vinyl active sites carried thereon can have a good compatibility with polyesterimide, heat-resistant polyesters, hydrogen-containing siloxane and modified epoxy; the intermediate is particularly suitable for preparing a high-temperature-resistant and corona-resistant solvent-free insulating varnish; and there are on volatile gases during use, thereby causing on pollution to the atmospheric environment.

Abstract: A polyoxazolidinone resin, a preparation method thereof and a use thereof in an impregnating varnish are provided. The polyoxazolidinone resin is prepared by reacting an alicyclic epoxy resin and a diisocyanate in the presence of a catalyst at 150° C. to 170° C. for 3 to 5 hours, wherein the molar ratio of the isocyanate radical in the diisocyanate to the epoxy radical in the alicyclic epoxy resin is 1:1.8 to 2.3. the impregnating varnish of the present invention uses the polyoxazolidinone resin as a bulk material in combination with acrylated epoxy resin and alicyclic epoxy resin, such that the impregnating varnish has the advantages of being heat resistant and flame retardant, low in cost, and eco-friendly, and finds use in insulation treatment of high-voltage and low-voltage electric machinery.

Abstract: A method for recycling rare earth from a wastewater from rare earth mining or from rare earth smelting, includes the steps of: removing oil from the wastewater to obtain a degreased wastewater; purifying the degreased wastewater to obtain a purified wastewater using a pretreatment system; recycling rare earth from the purified wastewater to obtain a rare earth slurry and a low rare earth wastewater using a rare earth recycling tank; treating the low rare earth wastewater to obtain ammonia gas using an ammonium degassing device; and converting the ammonia gas to obtain aqueous ammonia using an aqueous ammonium preparing system.

Abstract: A method for recycling rare earth from a wastewater from rare earth mining or from rare earth smelting, includes the steps of: removing oil from the wastewater to obtain a degreased wastewater; purifying the degreased wastewater to obtain a purified wastewater using a pretreatment system; recycling rare earth from the purified wastewater to obtain a rare earth slurry and a low rare earth wastewater using a rare earth recycling tank; treating the low rare earth wastewater to obtain ammonia gas using an ammonium degassing device; and converting the ammonia gas to obtain aqueous ammonia using an aqueous ammonium preparing system.

Abstract: A method for preparing an ultra-light-weight (ULW) proppant usable in the oil and gas industry. The method uses silane coupling agent and organic acid to modify silica fume (SF) to obtain modified SF that is lipophilic and hydrophobic. The modified SF is used as inorganic phase, and the polymerizable monomer is used as organic phase, and the organic-inorganic composite microspheres are obtained through suspension polymerization. The ULW proppant is obtained by drying, screening, and pre-oxidization of the composite microsphere. The ULW proppant has a density of about 1.109 g/cm3-1.278 g/cm3, which is close to that of water, a crushing rate of <5% at 52 Mpa, and a crushing rate of <7% at 69 Mpa. In the oil and gas industry application, water or salt water can be used to replace the high viscose guanidine gum as carrier, thus reduced cost of fracturing, and reduced environment pollution.

Abstract: A method for preparing an ultra-light-weight (ULW) proppant usable in the oil and gas industry. The method uses silane coupling agent and organic acid to modify silica fume (SF) to obtain modified SF that is lipophilic and hydrophobic. The modified SF is used as inorganic phase, and the polymerizable monomer is used as organic phase, and the organic-inorganic composite microspheres are obtained through suspension polymerization. The ULW proppant is obtained by drying, screening, and pre-oxidization of the composite microsphere. The ULW proppant has a density of about 1.109 g/cm3-1.278 g/cm3, which is close to that of water, a crushing rate of <5% at 52 Mpa, and a crushing rate of <7% at 69 Mpa. In the oil and gas industry application, water or salt water can be used to replace the high viscose guanidine gum as carrier, thus reduced cost of fracturing, and reduced environment pollution.