87 results about "Metallic mercury" patented technology

A carbon-based catalyst for flue gas desulfurization is brought into contact with a flue gas containing at least SO2 gas, oxygen and water vapor so that the SO2 gas can react with the oxygen and the water vapor to form sulfuric acid which is to be recovered. On a surface of the carbon-based catalyst, iodine, bromine or a compound thereof is added, ion exchanged or supported and a water-repellent treatment is applied. The carbon-based catalyst can also be used as a mercury adsorbent for flue gas treatment for adsorbing and removing metallic mercury from a flue gas containing metallic mercury, SO2 gas, oxygen and water vapor.

Provided is a process for integrating treatment of off gas through NOx removal, SOx removal and mercury removal, which could avoid high energy consumption resulting from high temperature required for the reaction, and a corresponding apparatus thereof. The process comprises the splitting of the off gas to a sub-stream off gas flow line as a carrier for the oxidizing agent. In the sub-stream line, a heating chamber is set for the decomposition of the oxidizing agent to form free radicals (when hydrogen peroxide is used, the free radicals formed are hydroxy and peroxy hydroxy free radicals) having stronger oxidative capacity than the original oxidants used, these free radicals carried in the sub-stream off gas are then combined with the unheated mainstream off gas, and react with the reducible contents such as NOx, SOx and mercury vapor in the off gas to generate NOx, SOx and mercury ions with higher oxidation state, wherein all the acidic products and mercury ions will be removed in the subsequent gas scrubbing device. The process and apparatus enable substantial reduction of energy required for oxidization and effective removal of NO2 and SOx as well as the reducible heavy metals such as metallic mercury, owing to only a portion of flue gas used as the carrier for the oxidizing and ionizing of the oxidative agents.

The invention belongs to the technical field of sulfur-containing organic polymer preparation, and discloses a method for preparing polythiourea by means of polymerizing multiple components of isocyanide, sulfur and amine and application of the polythiourea. The method includes carrying out reaction on amine monomers, isocyanide monomers and elemental sulfur in solvents; cooling, precipitating anddrying reaction products to obtain the polythiourea. The amine monomers are diamine compounds, and the isocyanide monomers are binary isocyanide compounds. The method and the application have the advantages that the method can be implemented under room-temperature and air conditions, is simple and is high in polymerization reaction yield and atom economy, and the polythiourea which is a product is easy to separate; the polythiourea prepared by the aid of the method contains abundant N and S heteroatoms, has special photoelectric properties and has a potential unique application value in the field of biological and chemical fluorescence detection, metallic mercury ion detection and mercury ion removal; the polythiourea is high in metallic mercury ion detection sensitivity, good mercury ionremoval effects can be realized by the polythiourea, and the removal efficiency of the polythiourea is higher than 99.99% and can reach drinking water standards.

To provide a method of and an apparatus for continuously measuring elemental mercury and bivalent mercury both contained in a gaseous medium fractionally with a simplified structure, the concentration of a total mercury (Metallic Mercury+Bivalent Mercury) and the concentration of elemental mercury contained in gases are measured continuously and fractionally. In the practice of this mercury measuring method, a first column 1, filled with a first fixed catalyst, and a second column 11, filled with a second fixed catalyst, are fluid connected in parallel relation to each other. The gases G are introduced into those first and second columns 1 and 11. In the first column 1, the first fixed catalyst collects and removes the bivalent mercury, but passes only the elemental mercury in the gases through the first column. In the second column 11, the second fixed catalyst reduces the bivalent mercury into elemental mercury and passes through the second column 11 the elemental mercury in the gases containing the elemental mercury into which the bivalent mercury has been reduced. The concentration of the elemental mercury in the gases, from which the bivalent mercury has been removed after passage thereof through the first column 1 and, also, the concentration of the elemental mercury in the gases into which the bivalent mercury has been reduced after passage thereof through the second column 11 are measured as the concentration of the elemental mercury contained in sampled gases and as the concentration of the total mercury in the sampled gases, respectively by utilization of first and second mercury measuring instruments.

The present invention provides an exhaust gas treatment method including oxidation treatment for converting metallic mercury contained in combustion exhaust gas into mercury chloride; and mercury removal treatment for removing mercury from the combustion exhaust gas by dissolving the mercury chloride in water, wherein a plurality of oxidation catalysts for performing the oxidation treatment are provided, and during the time when the oxidation treatment is performed, at least one of the oxidation catalysts performs catalyst performance restoration treatment without performing oxidation treatment. According to the present invention, the deterioration in mercury removal performance can be restrained even in continuous operation on condition that mercury is oxidized in a low temperature region not higher than 300° C.

To overcome the problem of a conventional catalyst and to provide an exhaust gas purifying catalyst that meets the requirement concerning Hg oxidation activity and SO2 oxidation activity; i.e., an exhaust gas purifying catalyst which specifically reduces percent SO2 oxidation, while maintaining percent Hg oxidation at a high level.The invention provides an exhaust gas purifying catalyst which comprises a composition containing oxides of (i) titanium (Ti), (ii) molybdenum (Mo) and / or tungsten (W), (iii) vanadium (V), and (iv) phosphorus (P), wherein the catalyst contains Ti, Mo and / or W, and V in atomic proportions of 85 to 97.5:2 to 10: 0.5 to 10, and has an atomic ratio of P / (sum of V and Mo and / or W) of 0.5 to 1.5, and an exhaust gas purifying method comprising exposing an exhaust gas containing a nitrogen oxide (NOX) and metallic mercury (Hg) to the catalyst in the presence of ammonia as a reducing agent, to thereby perform reduction of NOX contained in the exhaust gas and oxidation of metallic mercury (Hg) contained in the exhaust gas.

In an exhaust gas treatment, the amount of a highly corrosive mercury-halogenating agent to be added is reduced with the mercury-removing efficiency maintained high.A mercury-halogenating agent (40) and ammonia (30) are added to combustion exhaust gas from a boiler, the exhaust gas containing NOx, SOx and mercury. The exhaust gas is brought into contact with a CO / HC oxidation catalyst (50) and is then subjected to reduction denitration (60) in the presence of a solid catalyst. Thereafter, metallic mercury is oxidized to halogenated mercury. Then, the exhaust gas is wet-desulfurized (100) with the alkaline absorbing solution, and the halogenated mercury is removed.

The invention discloses an Fe3O4-rGO (reduced graphene oxide)-Ag composite material. Active components Fe3O4 and Ag are loaded on graphene oxide (GO) which is a carrier to obtain the Fe3O4-rGO-Ag composite material. The invention further discloses a method for preparing the Fe3O4-rGO-Ag composite material and application thereof. The Fe3O4-rGO-Ag composite material, the method and the application have the advantages that characteristics of large specific surface areas and multiple functional groups of reduced graphene oxide are utilized, silver and iron which are good in adsorption performance can be loaded, the silver is precious metal, the iron is a magnetic material, and accordingly the zero-valent mercury removal efficiency can reach 90% at least; magnetic composite adsorption materials can be separated and recycled by magnetic separation means, can be regenerated at the high temperatures and then can be reused, metal mercury with extremely high purity can be recycled, accordingly, the operation cost can be reduced to a great extent, and the Fe3O4-rGO-Ag composite material and the method can have direct economic benefits.

The present invention is one electrolytic process of reducing Yb, enriching Tu and Lu, and oxidizing Ce simultaneously. The electrolytic process reduces Yb into bivalent Yb ion in the cathode chamber so as to separate out Yb from the enriched Yb, Tu and Lu; oxidizes Ce into four-valent ion so as to separate out Ce. The electrolytic equipment has cathode of metal mercury or amalgam, anode of inert metal, anion exchange membrane to separate the anode chamber from the cathode chamber, cathode solution of sulfuric acid solution of pH 0.1-4.0 with enriched Yb, Tu and Lu, and anode solution of sulfuric acid solution of acidity 0.01-3.0 mol / L with enriched Ce. The present invention has low production cost, best utilization of electrolytic current and other advantages.

A method and system for removing from an aqueous system which is contaminated therewith: (1) mercury present as colloids, ions and / or organically bound compounds, and (2) hydrocarbons solubilized, dispersed, and / or emulsified in the said system. Pursuant to the invention the aqueous system to be treated (such as “produced water”) is passed successively through three filtration stages. The first filtration stage is provided with absorption media which effects reduction / removal of dispersed organically bound mercury species and of the dispersed and partially dissolved hydrocarbon phases, as well as of some colloidal mercury and other dissolved metallic species. The second filtration stage utilizes a salt modified reticulated granular filtration media for reduction / removal of slightly dissolved hydrocarbon phases, mercury in colloidal and ionic form and other dissolved metals. The third filtration stage is a polishing stage, which serves to further reduce by electroless or voltaic reduction residual elemental mercury and / or residual colloidal and ionic mercury. At this third stage metallic mercury is incorporated into a metallic matrix from which the mercury may preferably be recovered.

The invention discloses a rapid testing card for heavy metal mercury and a testing method thereof. The structure of the testing card includes a base board, absorption wafers and a cover film successively from bottom to top. At least one wafer for absorbing color-developing agents and at least one wafer for absorbing urease are respectively fixed on the base board, and the wafers are not overlapped mutually. The use amount ratio of the urease and the color-developing agents absorbed by the wafer per unit area is 3U: (1.6-3.2mL), and the color-developing agents contain components of, by mass, 0.05% to 2.5% of phenol red and 0.8% to 2% of urea. The testing card can test the content of mercury larger than or equal to 0.2 mg / L rapidly, accurately and conveniently; the test card is low in cost, simple and convenient to operate, short in testing time, in no need of professionals, sensitive in reaction and easy to observe and interpret; and the testing card is non-toxic and harmless and cannot cause environment pollution.