Method for recycling rear-earth elements form abandoned fluorescent lamps

Abstract

The invention relates to a method for recycling rear-earth elements form abandoned fluorescent lamps, wherein the method comprises the following steps of: breaking abandoned energy-saving lamps; separating fluorescent powder; and recycling rear-earth elements from the fluorescent powder. According to the invention, the method specifically comprises the following steps of: firstly breaking the abandoned energy-saving lamps mechanically in an enclosed container; separating the fluorescent powder out of the abandoned fluorescent lamps through a simple mechanical separation method; separating and recycling the rear-earth elements and other useful elements through carrying out a two-step acid dissolution method and adding oxalate for precipitation; fusing and refining solid powder insoluble in acid by using alkali metal carbonate; and then processing simply. Through the method provided by the invention, the reasonable recycling of all rear-earth element compositions in the abandoned energy-saving lamps can be realized, the rear-earth resources are expected to be comprehensively recycled maximally, and the method is simple and has wide application prospect.

Description

technical field [0001] The invention relates to a method for recycling rare earth elements in various waste fluorescent lamps, including energy-saving lamps, high-efficiency straight-tube fluorescent lamps, and trichromatic fluorescent lamps, and belongs to a method for environmental protection and recycling of electronic waste resources. Background technique [0002] At present, my country's lighting electricity consumption has accounted for 7-8% of the total electricity consumption. According to the "China Green Lighting Project" proposed by our country, lighting power saving has become an important aspect of energy saving. Power saving is to promote high-efficiency and energy-saving lighting appliances, improve the utilization rate of electric energy and reduce power consumption under the premise of ensuring illumination. Therefore, the traditionally used incandescent lamps have been gradually replaced by high-efficiency straight-tube fluorescent lamps, energy-saving lam...

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Problems solved by technology

[0003] At present, there are not many research reports on the recovery of rare earth elements in waste fluorescent lamps at home and abroad, but more domestic research focuses on the recovery of toxic pollutant mercury in fluorescent lamps (such as CN1902723), although there is a domestic patent (CN101150032) that reports Phosphor powder forms rare earth chlorides to recycle rare earth elements, but there are secondary environmental pollution problems and high processing costs, and it does not have the possibility of industrialization. There is also a patent (CN101307391A) that uses alkali dissolution, neutralizes with acid, and extracts with an extractant , and then separated by precipitation to obtain a mixture of rare earth phosphors. The steps are cumbersome, and it is difficult to carry out the prospect of industrialization

The method of recovering phosphors reported abroad generally uses selective dissolution of rare earth phosphors and then separates them by precipitation. The main problem is the co-precipitation of calcium and terbium, which limits the quality of the extracted rare earth phosphors (DE-A 34 10 989, DD-A246 551); there are also methods to selectively dissolve impurities and separate and purify rare earth phosphors. The existing problem is mainly the coexistence of fine glass slag and rare earth phosphors, which limits the reuse of rare earth phosphors (DE -A 196 17 942)

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