The method of cleaning solid waste from mercury
(57) Abstract:The invention can be used for the extraction of mercury from industrial solid wastes by oxidation with iodine or bromine. As a medium for dissolving iodine or bromine as oxidant proposed volatile organic solvents that can dissolve and the reaction products from the oxidation iodides or bromides mercury. The method consists of mixing the waste with extracting composition, the separation of the extract after stirring for 40-60 minutes at 18-22°C and the allocation of associated mercury from the extract by evaporation of the solvent or by passing the extract through a layer of activated carbon, eliminates the introduction of additional reagents for the specified salts of mercury, is achieved by simplification of the process and its intensification. 1 C.p. f-crystals. The invention relates to chemical methods of removing mercury from industrial solid waste and can be used for the purification of waste ore dressing, processing and recycling of fluorescent lamps, waste electronic industry and so onKnown chemical methods for removal of solid waste from mercury, including the application of iodine to oxidize the mercury contained in the RU patent N 2106421, class C 22 B 43/00, H 01 J 9/50, publ. 10.03.98, bull. N 7).The iodides of mercury are solid, insoluble in water, salts of different chemical composition, which cannot be separated from the unreacted residue, without prior dissolution. With this purpose, in the known methods using more complexing substances type KJ, NaJ, LiJ and the like, which with the iodides of mercury to form water-soluble compounds, for example, K2HgI4.Using known methods of water as a medium for dissolving iodine is not effective as it does not allows the use of additional reagents to separate the bound mercury from the solid residue, and does not allow to use as oxidant another halogen, for example bromine. Waste management only complexing substance (treatment option for patent N 2106421) does not provide a high level of treatment, even at a very high cost of the reagent due to a lack in the reaction mixture of free iodine to oxidize mercury.The closest to the technical nature of the claimed invention is the method according to US patent N 5226545, including the treatment of solid waste with an aqueous solution of iodine, as extracting sospeso selected as a prototype.Technical problem on which the invention is directed, is to develop a rapid and simple method for purification of solid waste from mercury by oxidation, excluding the formation of insoluble salts of mercury in the environment used for the dissolution of her oxidant, and as a result, would require additional processing reagents to dissolve them.The technical result that can be obtained by use of the invention is to simplify the method of cleaning while reducing time costs due to the use of a single solvent environment for oxidant and products of its reaction with mercury, as well as enhanced operational capabilities of the method through the use of another halide as an oxidizing agent.To solve the problem in the method of cleaning solid waste from mercury, including solid waste management extracting composition containing the oxidizing agent is iodine and dissolving its environment, the separation of the extract from the solid phase and the selection of extracts is associated with mercury, according to the invention as oxidant, in addition to iodine, use bromine, and as the environment, dissolving iodine or bromine, legality this solid waste management extracting composition of conduct for 40-60 minutes at 18-22oC, and the allocation of associated mercury carried out preferably by evaporation of solvent or by passing the extract through a layer of active charcoal.The difference of the proposed method known from US patent N 5226545 is to have the following characteristics:
- use as oxidant, in addition to iodine, bromine,
- use as environment, dissolving iodine or bromine, volatile organic solvents capable of dissolving and reaction products of these oxidants with mercury,
- treatment of solid waste extracting part for 40-60 minutes at 18-22oC,
- allocation of the associated mercury preferably by evaporation of solvent or by passing the extract through a layer of active charcoal.These differences allow to draw a conclusion on the conformity of the proposed method to the condition of novelty.The prior art has identified solutions that have all the signs consistent with the distinctive features of the proposed method, and therefore the latter meets the condition of inventive step.The inventive method is based on the identified solubility of iodides and bromides mercury in volatile organic solvents, advantage is.). Can easily be removed by evaporation or transmission through a layer of active charcoal and recycled solvent allows you to get the associated mercury, suitable for further use, without additional reagents to select it.The content of the oxidizing agents (iodine or bromine) extracting the composition should be sufficient to oxidize all of the mercury present in a given amount of solid waste, but in order to secure the extraction of mercury oxidants take in a small excess.The method is implemented as follows.Prepare extracting composition by dissolving the oxidizing agent (iodine or bromine) in one of the above or any other, suitable for this purpose organic solvent. The amount of solvent is calculated from the content of mercury in solid waste, exceeding it by 2-5%, and the amount of solvent is determined by the mass of waste and their morphological composition.Waste combined with extracting composition and stirred for 40-60 minutes at 18-22oC, and then filtered or centrifuged to wash the solid phase of the pure solvent. The extract is passed through the activated carbon layer ilaniya solvent. Last sent for reuse.The proposed method for the treatment of solid waste from mercury simple and high-tech. It does not require much time. Technological cycle is closed recirculation of the solvent. For implementing the method is suitable stocks of seized counterfeit alcohol.Example 1. 100 g of the phosphor containing 0.8 wt.% mercury, pour 200 ml extracting composition, prepared by dissolving bromine in ethyl alcohol at the rate of 0.5 wt.% bromine in 100 ml of alcohol. The mixture is stirred for 60 minutes at 20oC, then filtered and washed the solid phase is pure ethanol, and separated from the solid phase extract (in this case the filtrate) is passed through a column of activated carbon to obtain a solid residue containing mercury salts. Ethanol is sent for reuse.The mercury content in the phosphor after processing 0.0012 wt.%
Example 2. 50 g of cullet from mercury lamps with a mercury content of 0.12 wt.% treated as in example 1 extracting composition (50 ml) containing 0.25 wt.% iodine dissolved in chloroform. The conditions: temperature 22oC, time - 50 minutes.Soderjali carried out in industrial conditions on the equipment of chemical productions. 1. The method of cleaning solid waste from mercury, including solid waste management extracting composition containing the oxidizing agent is iodine and dissolving its environment, the separation of the extract from the solid phase and the selection of extracts is associated with mercury, characterized in that as the oxidant, in addition to iodine, use bromine, and as the environment, dissolving iodine or bromine, volatile organic solvents capable of dissolving and reaction products of these oxidants with mercury, while the processing of extracting solid waste composition should be performed within 40 - 60 minutes at 18 - 22oC.2. The method according to p. 1, characterized in that the selection associated mercury is carried out by evaporation of solvent or by passing the extract through a layer of activated carbon.
FIELD: utilization of mercury-containing devices; processing rejected luminescent lamps and mercury-containing devices and devices whose service life has expired.
SUBSTANCE: plant for utilization of mercury-containing devices includes working bath, unit for breaking and treating the mercury-containing devices with liquid medium which is made in form of container with breaking devices and devices for supply of liquid medium, vibrator, working solution reservoir connected with breaking device by means of drainage pipe line laid in lowest point of working bath; plant is also provided with pipe lines equipped with fittings and pump for transfer of liquids; it is also provided with water reservoir which is connected with breaking device by means of drainage pipe line laid at definite height above bottom of working bath; working bath, water reservoir and working solution reservoir are combined in system which makes it possible to fill working bath in turn with water or with working solution by means of one pump; breaking device is made in form of cross-piece with knives secured on it. Proposed method of utilization of mercury-containing devices includes grinding of such devices under layer of water at continuous washing of luminescent substance, forming the suspension and settling mercury in form of finely-dispersed particles on bath bottom, after which mercury is subjected to neutralization with the aid of said plant. Breaking the mercury-containing devices and washing-off the luminescent substance will be performed by vibration; neutralization is accompanied by forming of insoluble calomel.
EFFECT: possibility of performing chemical demercuration at temperature close to surrounding temperature.
3 cl, 5 dwg