33results about How to "Cost-effective recycling" patented technology

The invention relates to a method for recovering sludge phosphorus from an urban sewage treatment plant, belonging to the technical fields of sludge treatment and resources. The method comprises the following steps: respectively carrying out gravity thickening on sludge releasing sludge phosphorus, sludge phosphorus releasing on sludge after the gravity thickening, solid-liquid separation on sludge after the sludge phosphorus releasing, sludge phosphorus recovery on supernatant fluid rich of phosphorus after the solid-liquid separation, and the like; the sludge phosphorus releasing on sludge after the gravity thickening is realized by treating the sludge by an acidification and normal-pressure microwave radiation combination method; and the sludge phosphorus recovery on supernatant fluid rich of phosphorus after the solid-liquid separation is realized by treating the supernatant fluid rich of phosphorus by a calcium phosphate crystallization process to obtain the deposit containing calcium phosphate crystal, then filtering the deposit containing calcium phosphate crystal and finally recovering the sludge phosphorus. The method not only can efficiently recover the phosphorus in the sludge from the urban sewage treatment plant, but also can achieve the aims of reducing the sludge and improving the depositing performance of the sludge.

The invention provides energy efficient depolymerization of polyesters such as post-consumer polylactic acid. Ultrasonic induced implosions can be used to facilitate the depolymerization. The expanding market of polylactic acid-based plastic products, such as water bottles and packaging materials, has raised concerns of contaminating the recycling stream, which is largely filled with petroleum-based plastics. Thus the development of an energy efficient and economically viable PLA recycling process is urgently needed. Post consumer PLA was exposed to methanol as the suspension media in the presence of organic or ionic salts of alkali metals such a potassium carbonate and sodium hydroxide as depolymerization catalysts to provide high quality lactic acid monomers in high yield.

The invention discloses a treatment device for pressing alkali. The treatment device for the pressing alkali comprises a pressing alkali tank, a liquid supply pump I, a tubular filter I, a buffer tank, a liquid supply pump II, a tubular filter II, a pressurizing pump and a safety filter. A recovering method for the treated pressing alkali comprises the following steps of: step a, injecting the pressing alkali into the tubular filter I through the liquid supply pump I, intercepting greater semi-fibers by a filtering element and enabling alkali liquor to enter the next-stage buffer tank; step b, enabling the alkali liquor subjected to primary separation to enter the tubular filter II for further separating semi-fiber impurities; and step c, pressurizing the alkali liquor and removing fine particles in the alkali liquor by the safety filter so as to ensure the quality the alkali liquor at an outlet. According to the treatment device disclosed by the invention, on the principle of not changing the properties of original alkali liquor, the current treating device for the pressing alkali is improved and intensified for overcoming the defects; and by optimizing a treatment process of the traditional device, the complete device is compact in structure, effective separation of the semi-fibers from the alkali liquor is realized and the pressing alkali liquor is recovered efficiently and economically.

The invention provides an open powder making steam warm air type boiler unit used for burning raw coal and being connected with a turbine unit with a turbine. The open powder making steam warm air type boiler unit is characterized in that a drying agent mixing chamber is connected with a smoke extraction opening and a gas outlet of a coal powder collector, a first part exhaust extracted from exhaust and part of smoke extracted out of the smoke extraction opening are mixed and used as drying agents to be fed to a raw coal pre-drying device, a cold air pre-heating device preheats environment cold air to obtain warm air through low-pressure steam extracted out of a steam extraction opening of the turbine, an air preheater further heats the warm air to obtain hot air, one part of the hot air and the environment cold air are mixed to be used as primary air, an air and powder mixer mixes the primary air and coal powder to obtain air and powder mixtures, and the other part of the hot air is used as secondary air to be directly fed in a coal powder burner. The invention further provides a power generation system including the open powder making steam warm air type boiler unit and the turbine unit with the turbine.

A method of recycling nickel, cobalt and iron from low-grade laterite-nickel ore includes following steps: (1) performing washing classification to obtain high-silicon and -magnesium ore and low-silicon and -magnesium and high-iron ore; (2) adding enough concentrated sulfuric acid to the high-silicon and -magnesium ore slurry, and performing a reaction at 160-280 DEG C; (3) performing solid-liquid separation to obtain a normal-pressure leached residue and a normal-pressure leached liquid; (4) adding the normal-pressure leached liquid and the low-silicon and -magnesium and high-iron ore slurry according to proportion and performing pressurized leaching to the mixture at 195-240 DEG C; (5) purifying a pressurized-leached filtrate; (6) recycling nickel and/or cobalt through precipitation of sulfides or hydroxides or other recycling methods; and (7) washing the normal-pressure leached residue with a 10% sodium carbonate solution and drying the normal-pressure leached residue to obtain an iron concentrate powder product. The method is wide in adaption range of the laterite, is high in leaching rate of the nickel and the cobalt, is small in normal-pressure leaching device, is short in time and is high in efficiency. The normal-pressure leaching device is a middle-low pressure device, thereby avoiding defects that a high-pressure kettle is high in cost and is liable to scale. The method is quite low in sulfuric acid consumption. The main component, iron, in the ore can be recycled economically and effectively. The method is less in amount of waste residue and can effectively utilize the waste residue.

The invention relates to an oil field associated gas recycling device and method, and belongs to the technical field of natural gas hydrate application. Through the improved design of a low-temperature separator structure, oil field associated gas enters the low-temperature separator to realize multi-section removal of heavy hydrocarbon after primary separation and low-temperature cooling; a firstrefrigerating system and a second refrigerating system are designed, so that flow of each pipeline refrigerant is regulated and controlled through a data monitoring unit; a field process is combined,a hydrate prizing production device integrating heavy hydrocarbon removal, boosting, liquid storage, hydration reaction, hydrate slurry external conveying treatment and a refrigerating unit is provided. According to the oil field associated gas recycling device and method provided by the invention, oil field associated gas is converted into hydrate, so that associated gas heavy hydrocarbon removal, hydrate quick preparation, hydrate generation speed calculation, generation amount control and the like can be realized, so that part of the resource waste problems due to the fact that associatedgas of a far oil field without pipeline facilities or not worthy of laying pipelines can be effectively solved.

The invention relates to the technical field of a hydrometallurgy process of laterite-nickel ores and in particular relates to a method for recovering nickel, cobalt and iron from laterite-nickel ores. The method comprises the following steps: adding sufficient concentrated sulfuric acid to muck soil pulp to carry out reaction at a high temperature of 95-120 DEG C so as to dissolve most soluble nonferrous metals and soluble iron; carrying out solid-liquid separation to obtain atmospheric pressure leaching residues and atmospheric pressure leachate; proportionally adding the atmospheric pressure leachate and limonite pulp to a pressurized reactor to undergo pressure leaching at 195-240 DEG C; carrying out solid-liquid separation to obtain pressure leaching residues and pressure leachate; purifying the pressure leaching filtrate to recover nickel and cobalt; washing and then drying the pressure leaching residues to obtain fine iron powder products. The method has the advantages that the method can be used for simultaneously treating muck soil and limonite; the nickel and cobalt recovery rate is high; atmospheric pressure leaching equipment is small, is short in time and has high efficiency; waste residues are small in quantity and can be effectively utilized.

The invention relates to the technical field of a hydrometallurgy process of laterite-nickel ores and in particular relates to a method for recovering nickel, cobalt, iron, silicon and magnesium from laterite-nickel ores. The method comprises the following steps: adding sufficient concentrated sulfuric acid to muck soil pulp to carry out reaction at a high temperature of 95-120 DEG C so as to dissolve most soluble nonferrous metals and soluble iron; carrying out solid-liquid separation to obtain atmospheric pressure leaching residues and atmospheric pressure leachate; proportionally adding the atmospheric pressure leachate and limonite pulp to a pressurized reactor to undergo pressure leaching at 195-240 DEG C; carrying out solid-liquid separation to obtain pressure leaching residues and pressure leachate; purifying the pressure leaching filtrate to recover nickel and cobalt; washing and then drying the pressure leaching residues to obtain fine iron powder products; carrying out sieving treatment on the atmospheric pressure leaching residues to obtain a high-grade silicon dioxide product and building sand. The method has the advantages that the method can be used for simultaneously treating muck soil and limonite; the nickel and cobalt recovery rate is high; atmospheric pressure leaching equipment is small, is short in time and has high efficiency; waste residues are small in quantity and can be effectively utilized.

The invention relates to the technical field of hydrometallurgical processes of lateritic nickel ore, and particularly relates to a method of recovering nickel, cobalt, iron, silicon and magnesium from lateritic nickel ore. The method includes following steps: adding sufficient concentrated sulfuric acid into saprolite pulp, and reacting at 95-120 DEG C to dissolve most of soluble non-iron metals and soluble iron; performing solid liquid separation to obtain atmospheric-pressure leaching slag and atmospheric-pressure leachate; adding the atmospheric-pressure leachate and limonite ore pulp into a pressurized reactor according to a ratio and performing pressure leaching at 195-240 DEG C; performing solid liquid separation to obtain pressure leaching slag and leachate of pressure leaching; purifying the leachate of pressure leaching to recover the nickel and the cobalt; washing pressure leaching slag and drying to obtain a fine iron powder product; and screening the atmospheric-pressure leaching slag to obtain a high-grade silicon dioxide product and building sand. The method can achieve treatment of the saprolite and the limonite at the same time, and is high in nickel and cobalt leaching rates, small in atmospheric-pressure devices, short in time and high in efficiency. Waste slag is low in amount and can be effectively utilized.

The invention discloses a method for hydrothermally recovering high-purity terephthalic acid from printing and dyeing white mud, which belongs to the technical field of solid waste recycling in the textile printing and dyeing industry. The recovering method comprises the following steps of washing the alkali-decrement white mud by using a dilute acid solution containing a surfactant, and then carrying out solid-liquid separation to obtain a white mud filter cake, dispersing the white mud filter cake in water, adjusting the pH value, and carrying out a hydrothermal reaction in a hydrothermal kettle, carrying out solid-liquid separation on the hydrothermal product, and washing an obtained filter cake by using a proper amount of pure water, and carrying out solid-liquid separation again, taking the solid, and drying to obtain the high-purity terephthalic acid. The pure terephthalic acid recovered by the method has the impurity content of less than 1.5% and the average grain size of more than 145 microns, and can be recycled for polyester synthesis or plasticizer synthesis, so that the printing and dyeing white mud is economically and effectively recycled.