Beijing University of Technology

University of Science and Technology Beijing

Dean Pan

Yufeng Wu

Jian Li

Tieyong Zuo

Shengen Zhang

Jianjun Tian

Wei Wang

Bo Liu

Qijun Zhang

Xiaoguang Zhang

Min Yang

Hu Liu

Guanjun Li

Zhe Tan

Xiaomin Liu

Yifan Wang

Ruhao Kong

Xudong Sun

The invention belongs to the field of bromine recovery from waste circuit board, and particularly relates to a method for recovering high-purity sodium bromide from bromine-containing crude salt. The invention mainly includes the steps of acidification oxidation, multi-stage extraction, and cooperative back extraction. Compared with traditional chlorine oxidation and single urea back extraction technology, the acidification oxidation process can be effectively controlled by reasonable adjustment of the added amount of hydrochloric acid and sodium chlorate, and the tail gas can be absorbed and reused to avoid secondary pollution and resource waste. At the same time, urea is used with sodium carbonate for cooperative back extraction to achieve a high back extraction rate which greatly reduces the amount of urea, and obtains high-purity sodium bromide crystals. The efficient recovery of bromine resources in bromine-containing crude salt is realised. The benefits of the invention are: high product purity, simple operation, environmental friendliness.

Method for recovering high-purity sodium bromide from bromine-containing crude salt

The present invention provides a method for preferentially recovering manganese from waste lithium-rich manganese-based cathode material, the method comprising: step 1) calcination and leaching: mixing the waste lithium-rich manganese-based cathode material with ammonium sulfate and then performing low-temperature calcination, leaching the calcination product with water, and then performing solid-solution separation to obtain a leaching solution; step 2) complexing and manganese separating: adding ammonium sulfite to the leaching solution obtained in step 1) for a complex reaction to obtain manganese-rich residue; step 3) oxidation leaching: adding an oxidant to the manganese-rich residue obtained in step 2) to perform oxidation leaching, and adjusting the pH of the solution to obtain a manganese-rich solution; and step 4) extracting and stripping. The method realizes the preferential and productive recovering of manganese from waste lithium-rich manganese-based cathode materials, avoids the negative impact of polymetals in the conventional recovery process, and has economic and environmental benefits.

Method for preferentially recovering manganese from waste lithium-rich manganese-based cathode material

A green resource-based method of thermal mass synergy in waste Integrated circuit board mainly includes carbonization cracking system, crushing and separation system, gasification cracking system and heat value utilization and comprehensive recovery system. Compared with existing techniques, carbonization cracking system can realize the dry distillation cracking of organic matter in waste integrated circuit board which converts carbon, hydrogen and other elements into fuel carbonized cracking gas and cracking oil, the heat from the combustion of the carbonization cracking gas of the invention provides the energy needed for the carbonization cracking to realize self-heating carbonization cracking. Carbonization cracking products are cracked and separated to solve the problems such as hard to break and organic coating metal caused by direct crushing and separation of traditional circuit boards which Improves crushing and separation effect; gasification cracking system achieves the comprehensive utilization of carbon, the gasified cracking gas can be used as a heat source for subsequent valuable metal recovery to further improve the utilization rate of calorific value. The invention has the characteristics of: high heat value utilization rate, low energy consumption, high metal recovery rate, short process recovery of valuable metal and no pollution of flue gas.

Green resource-generating method based on thermal mass synergy of waste integrated circuit board

A method for preparing an ecological foamed ceramic from lepidolite filter mud whole waste belongs to the field of environmental protection and resource reuse. The ecological foamed ceramic with excellent properties can be prepared by using lepidolite filter mud as the main raw materials, including ball milling, homogenization, drying, material distribution, and heat treatment. The amount of lepidolite filter mud in the present invention accounts for more than 90%, which is a whole waste utilization and can achieve high-value utilization of bulk lepidolite filter mud. The present invention uses a composite foaming agent combined with a foaming technology and has the advantages of rapid foaming and controllable pore size compared with a single foaming agent. The ecological foamed ceramic prepared by the present invention meets the industrial standard of CJ/T 299-2008 'Artificial ceramic filter material for water treatment' and has potential application value in domestic sewage treatment.

Method for preparing ecological foamed ceramic from lepidolite filter mud whole waste

The invention discloses a method for preparing lead smelting slag glass-ceramics based on the oxidation of silicon-rich silicon smelting slag and composition adjustment, and belongs to the technical field of resource utilization of smelting slag rich in monatomic silicon. The method comprises the steps: mixing the silicon slag rich in monatomic silicon with an oxidant, a fluxing agent and a clarifying agent according to a formula ratio, ball-milling and screening to obtain a tempering raw material with uniform size, and performing high-temperature oxidation melting on the tempering raw material to form an oxidation-state molten tempering material; and carrying out further mixed melting on the molten tempering material and hot lead slag, carrying out water quenching to obtain basic glass, and carrying out heat treatment system on the obtained basic glass to form the glass ceramics. According to the method, the smelting slag rich in monatomic silicon is subjected to oxidation tempering and mixed melting with the hot lead slag to prepare the basic glass, and the glass ceramics are obtained by regulating and controlling the heat treatment system of the basic glass. The method is simple in technological process, high in production efficiency and low in cost, achieves the collaborative high-value conversion target of the silicon-rich silicon slag and the lead slag, and is easy to industrially popularize and apply.

Method for preparing lead smelting slag glass-ceramics based on the oxidation of silicon-rich silicon smelting slag and composition adjustment

The invention relates to the field of efficient separation and recovery of bromine by full wet method, especially to a two-step separating method of bromide and recovery of lead and zinc from printed circuit board Incineration ash. It mainly includes first sodium hydroxide alkaline leaching, secondary sodium peroxide alkaline leaching, pH adjustment, separate lead and zinc, bromide evaporation and crystallization to recover crude bromide and other steps. Compared with traditional comprehensive recovery process of ash, the invention uses sodium hydroxide to dissolve bromide, lead and zinc, and uses the strong oxidation of sodium peroxide in alkaline environment, copper bromide and other bromine are oxidized and leached; through two-step method, the efficient leaching of bromine, lead and zinc is realized, silver and other precious metals are enriched at the same time. It is beneficial to subsequent recovery of precious metals and has the characteristics of short tail liquid discharge.

Method of separating and recovering bromine from printed circuit board incineration ash by two-step process

The invention relates to a method for multi-metal products recovery from pyrolytic waste integrated circuit boards. The method mainly comprises the steps of smelting and blending, atomization, acidolysis and filtration, noble metal recycling, copper extraction and back extraction, nickel extraction and back extraction. Compared with the prior art, the method has the advantages that smoke pollution and the smelting slag treatment in the process of preparing a black copper ingot through multi-metal collaborative smelting are reduced, and the problems of low anode efficiency of the black copper electrolysis process are solved. Meanwhile, the high-temperature high-oxygen atomized gas generated in the atomizing process provides a heat source and an oxygen source for subsequent acidolysis, so that the energy consumption is further reduced. The method has the advantages such as short process, remarkable energy conservation and emission reduction.

Comprehensive recovery method of pyrolysis polymetallic product from waste integrated circuit board

The invention relates to the field of comprehensive recovery of valuable elements such as bromine, base metal and precious metal from incineration ash, especially relates to a method for enriching precious metals from printed circuit board incineration ash by bath smelting-chlorination circulation process. The process mainly comprises pretreatment of the printed circuit board Incineration ash and circulation-chlorination enrichment process for precious metals. The crude copper, crude zinc sulfate, bromine, lead chloride and precious metal enriched slag are obtained. Compared with the traditional process, it realizes the cycle enrichment of precious metals as well as avoids the loss of valuable metals and secondary pollution caused by tail liquid discharge.

Method for enriching precious metals from printed circuit board incineration ash from molten pool by circulating chlorination

A method of pretreatment and bromine recovery of PCB Incineration ash is disclosed that relates to the field of comprehensive recovery of valuable metals by full wet method, especially relates to a method of valuable metals and bromine recovery, precious metals enrichment in pretreatment process of PCB Incineration ash. The major steps includes alkali leaching, Cu extraction back-extraction, neutralization-precipitation to separate, Bromine evaporative crystallization, regeneration, acid pickling, Zn evaporative crystallization, removal of Zn and Cu. Compared with the traditional comprehensive recovery process of ash, the invention can separate bromine from ash and recover valuable metals such as copper, zinc and lead with the maximum extent, at the same time, the enrichment of silver and other precious metals is beneficial to the subsequent recovery of precious metals. It has high added recovery value and no tailless discharge.

Method of pretreatment and bromine recovery of PCB incineration ash

A method of recovering bromide from bromine-containing smelting ash relates to the field of high efficient separation and recovery of bromine by total wet method. It especially relates to the method of high efficiency separation of bromine salt and lead, zinc recovery of circuit board smelting ash by two-step method. It mainly comprising: sub-molten salt leaching, washing, separate Lead and zinc by adjusting the pH of industrial sulfuric acid, membrane separation and concentration, reuse of water, crude bromine salt recovery by evaporation crystallization of bromine salt. Compared with the traditional baking and recycling process of ash, the invention adopts sodium hydroxide submolten salt leaching technology and membrane separation and concentration technology, to reduce the reaction temperature and tailings discharge greatly, which has a good effect of energy saving and emission reduction.

Method of recovering bromide from bromine-containing smelting ash

A method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing belongs to the area of comprehensive recovery and high value utilization of metallurgical waste residue. In this method, cyanide tailings, bentonite, calcium chloride, coal powder and albite are mixed by ball milling according to certain weight ratio to get a mixture. After drying and roasting twice, dust is collected from the roasted ash, the obtained polymetallic ash is collected and treated. The secondary calcined material is cooled to obtain ceramsite. The invention volatilizes and recovers the valuable metal in the roasting and sintering process of cyanide tailings and directly prepares the ceramsite through reasonable batching, which achieves the effect of recycling cyanide tailings and high-value utilization, can create good economic and environmental benefits, and has significant effect of energy saving and consumption reduction.

Method for recovering valuable metals and simultaneously preparing ceramsite by roasting cyanide tailing

The invention provides a pollution-free reuse method for iron-based grinding waste, involving the technology of recycling economy, with special reference to the metallurgical industry, iron-based grinding waste green recycling technology. The present invention of the iron grinding waste recycling and reuse methods includes degreasing, heat treatment, sieving, matching, and obtains iron-based alloyed powders, which can be used in SHS lined steel pipe, powder metallurgy structural component, magnetic grinding, thermal spray. More than 95% iron-based alloyed powders can be recycled from wide source of iron-based grinding waste. The invention has the advantage of low cost, no secondary pollution and wide application.

Pollution-free method for recycling iron-based grinding waste

The invention related to the recycling field of waste printed circuit boards (WPCB), and especially involved a complete non-cyanogens wet process for green recycling of WPCB, which belonged to the field of recycle economy. In the invention, the process included that WPCB were broken by the jaw crusher, and then mixed copper powders and nonmetallic powders were separated by the method of air classification, the mixed copper powders were smelted and casted to get copper anode plates, the copper was purified by electrolytion, the valuable metals (such as copper, gold, silver, platinum and palladium, lead and tin) were recycled from the copper anode slime, and the waste water was recycled. The recovery ratio of all-metal was above 98%. The purity of the cathode copper was up to 4N level. The ratio of de-coppering was above 96%. The recovery ratio of gold was above 98.

Complete non-cyanogens wet process for green recycling of waste printed circuit board

The invention belongs to the field of recycling of resources, in particular to a method for waste rare earth luminescent material by dual hydrochloric acid. First hydrochloric acid was used to dissolve the red phosphor powder (YO:Eu) priority, and yttrium-rich rare earth chloride solution and residue were obtained after filtered. Residue's major components were green and blue phosphor powder, and the removal of Cain filtrate was conducted by using NaSO, and CaSOprecipitation separation was conducted to get rich rare earth chloride solution, europium and yttrium. Residue was mixed with alkali to perform alkaline fusion at high temperature to decompose green and blue powder, then sodium aluminate, magnesium, barium and rare earth oxides were obtained. Alkaline fusion products were washed with water, and filtered, and then sodium aluminate solution and residues containing rare earth oxides were obtained.

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Beijing, China

Dean Pan