45results about How to "Realize closed-loop recycling" patented technology

The invention discloses a method for separating and recovering valuable elements uranium, thorium, rare earth and monazite concentrate and zircon concentrate from monazite slag. The method is characterized by comprising the following steps of: acid leaching, filter pressing, washing, extraction of valuable components and treatment of filter residue. According to the invention, the monazite slag is leached by weak acid at a low temperature, and the liquid phase and solid phase are easy to separate; and meanwhile, the waste acid of residual liquid is circularly used, the discharge of wastewater is reduced, the consumption of sulfuric acid and new water as well as the wastewater treatment cost are reduced, the production cost is lowered, the recovery rate of the valuable elements uranium, thorium and rare earth is greater than 97%, and the discharge of radioactive wastewater and waste residue is avoided in the whole technology.

The invention discloses a separation and recovery method of uranium, thorium and rare earth in monazite slag, namely a method for separating and recovering valuable elements uranium, thorium and rare earth from monazite slag. The method is characterized by comprising the following steps of: acid leaching, filter pressing, washing and extraction of valuable components. According to the invention, the uranium, thorium and rare earth are leached out by weak acid at a low temperature, and the liquid phase and solid phase are easy to separate; the secondary slag is subjected to beneficiation and alkaline decomposition by a beneficiation technology, and closed-loop circular recovery of uranium, thorium and rare earth is realized; and meanwhile, the waste acid of residual liquid is circularly used, the discharge of wastewater is reduced, the consumption of sulfuric acid and new water as well as the wastewater treatment cost are reduced, the production cost is lowered, the recovery rate of the valuable elements uranium, thorium and rare earth is greater than 97%, and the discharge of radioactive wastewater and waste residue is avoided in the whole technology.

The invention relates to a method for recycling multiple elements of liquid after cyanided tailing flotation, belonging to the technical field of gold smelting, cyanided tailing flotation of lead and copper concentrate, and waste water treatment of sulfur concentrate. The method comprises the following steps: obtaining lead concentrate through flotation; comprehensively recycling gold and silver from liquid after lead flotation; obtaining copper concentrate through flotation; comprehensively recycling gold, silver and copper from liquid after copper flotation; obtaining sulfur concentrate through flotation; recycling gold and silver through gold-loaded activated carbon desorption electrodeposition; and the like. By the method, the comprehensive utilization efficiency of resources is improved, closed loop recycle of the liquid in a flotation system is achieved, zero discharge of wastewater is achieved, pollution to the surrounding environment is reduced, and ultimately the economic efficiency of an enterprise is improved.

The invention relates to a process of recovering ammonia from ammonia-nitrogen wastewater and exhaust gas of tungsten metallurgy. The process is characterized by comprising the following steps: introducing ammonium paratungstate crystal steam and ammonia tail gas into a rectifying tower by virtue of an induced draft fan, maintaining the temperature in a range of 90-95 DEG C and condensing and recovering ammonia by using a steam separator; pumping kettle raffinate and ammonia-nitrogen wastewater which are generated after rectifying the ammonia-nitrogen wastewater into a stirring tank, adding sodium hydroxide for ammonia activation, and adjusting the pH value to 10-11; after ammonia activation, pumping to an air stripping tower, and meanwhile, introducing ammonia wastewater generated by ammonia activation into the air stripping tower, adding sodium hydroxide to adjust the pH value to 10-11.5, and controlling the temperature at 45-90 DEG C and carrying out air stripping for 2 hours; feeding ammonia gas generated in the air-stripping process and ammonia gas which is not condensed by the steam separator into a hydrochloric acid spray tower for circular adsorption to generate ammonium chloride and returning to the main process to prepare an analytical solution. The process provided by the invention is simple in process flow, stable in treatment effect, less in equipment investment, free from secondary pollution and low in treatment cost.

The invention discloses a blending method of dry coke quenching dust-removal ash in a coal blending process. The blending method comprises the following steps: transporting dust-removal ash generated by dry coke quenching every day to a coal storage yard through an ash discharge opening, arranging the dust-removal ash near low-sulfur coking coal of which the content of sulfur is less than 0.4% and low-ash meager lean coal of which the content of ash is less than 8.5% which can be blended for separately storing; according to the blending ratio required by the blending instruction of a forklift in a coal blending workshop, fully and uniformly blending the dry coke quenching dust-removal ash, low-sulfur coking coal and the low-ash meager lean coal at a weight ratio of 1:5:5 to form novel mixed dust-removal ash; conveying the mixed dust-removal ash to a coal blending bin, blending the mixed dust-removal ash and 1 / 3 coking coal, gas coal, coking coal and meager lean coal at a weight ratio of 7: 3 and rich coal to form into-the-furnace coal, crushing the into-the-furnace coal, adding water and conveying to the coal storage bin for coking coal production to replace partial meager lean coal for return blending and coking, wherein the mixed dust-removal ash, the 1 / 3 coking coal, the gas coal, the coking coal and meager lean coal at a weight ratio of 7:3 and the rich coal respectively account for 15%, 32%, 15%, 21% and 17% of the into-the-furnace coal in weight ratio. The process is convenient to operate and has the characteristic of high flexibility.

The invention relates to a method for preparing titanium tungsten powder by recycling waste SCR denitration catalyst. The method comprises the following steps that the waste SCR denitration catalyst is pretreated so as to obtain pretreated waste catalyst powder; activated treatment is carried on the pretreated waste catalyst powder by using sulfuric acid, and after the waste catalyst powder is cooled and diluted, crude activated slurry is obtained; glass fibers are removed in the crude activated slurry to obtain purified and activated slurry; the activated slurry is heated and purified to obtain a reconstructed slurry; the reconstructed slurry is filtered so as to obtain a solid-phase product and a filtrate; and solid-phase products are sequentially washed, dried and calcined to obtain titanium-tungsten powder products. According to the method, the waste SCR denitration catalyst is converted into the titanium tungsten powder, and the whole process is simple in process, so that the process complexity caused by the step of extracting Ti and W metal components step by step is avoided, the cost is high, the recovery rate of Ti and W exceeds 97%, and the obtained titanium tungsten powder products meet the requirements of industry indexes can completely replace fresh titanium tungsten powder, and are used for production of the SCR catalyst.

The invention discloses a treatment method of tailings after the separation and recovery of monazite slag, namely a treatment method of tailings after separating and recovering valuable elements uranium, thorium and rare earth from monazite slag. The method is characterized by comprising the following steps of: acid leaching, filter pressing, washing and treatment of filter residue. According to the invention, the tailings are leached out by weak acid at a low temperature, and the liquid phase and solid phase are easy to separate; the secondary slag is subjected to beneficiation and alkaline decomposition by a beneficiation technology, and closed-loop circular recovery of uranium, thorium and rare earth is realized; and meanwhile, the waste acid of residual liquid is circularly used, the discharge of wastewater is reduced, the consumption of sulfuric acid and new water as well as the wastewater treatment cost are reduced, the production cost is lowered, the recovery rate of the valuable elements uranium, thorium and rare earth is greater than 97%, and the discharge of radioactive wastewater and waste residue is avoided in the whole technology.

The invention discloses a method for treating ammonia nitrogen in tungsten smelting by using extraction absorption. According to the method, the recovery rate of the ammonia nitrogen is further improved, and the working environment is improved and the production cost is decreased. Primary extraction: organic phase extractants are added to weak aqua ammonia recycled by evaporation to perform extraction to obtain ammonium ions NH4+, and free water and hydroxide ions in ammonia water enter extraction residual liquid water phases; secondary extraction: industrial concentrated hydrochloric acids are added in extracted organic phases, heavy phases after reverse extraction are ammonium chloride at the bottom; light phases containing P507 organic phases enter a next circle for extraction after washing; an reverse extraction solution of an ammonium chloride solution is subjected to ammonia absorption; ammonia water with a concentration of 110g / l returns to a tungsten smelting departure and transfer procedure to serve as an analyzing agent; and final washing: salt-free water is added to organic phases after reverse extraction, organic phase residual ammonium chloride is guaranteed to be discharged as far as possible, an after-washing solution is an ammonium chloride solution, the ammonium chloride solution and the reverse extraction of the last step are subjected to ammonia absorption, and an organic phase extraction agent P507 after washing enters a next circle for usage. The method further improves the ammonia nitrogen recovery rate, the work environment is improved, and the production cost is reduced.

The invention relates to a green recycling method for a honeycomb denitrification catalyst, which belongs to the field of flue gas denitrification and material recycling. Two process routes of regeneration and re-preparation are set up, and the regeneration production line and the re-preparation production line are arranged side by side; the regeneration process or the re-preparation process is selected according to the performance of the waste honeycomb denitrification catalyst for green recycling; the regeneration process and the re-preparation process The basis for selection is: the axial and radial compressive strengths of spent honeycomb denitration catalysts are ≥1.0 and ≥0.2MPa respectively, and the specific surface area is ≥40.0m 2 / g, the regeneration process route is selected; otherwise, the re-production process route is selected. The green recycling method of honeycomb denitrification catalyst provided by the present invention combines regeneration and re-preparation process, fully utilizes the valuable components in the spent denitrification catalyst, and greatly saves the amount of water, which can realize the closed loop of denitrification catalyst recycle.