The method of disposal of electroplating sludge

 

(57) Abstract:

The invention relates to chemistry, in particular to methods of disposing of waste galvanic production by processing the last in the final target product. The method of disposal of electroplating sludge with obtaining catalyst includes preparation of starting material, the preparation of the molding paste, forming, final heat treatment, electroplating sludge taken from the main content, wt.%: Fe2O3- 40-45, SIO - 10-15, CR2O3- 5-10, additionally conduct pre-activation when 120-550°C and mechanochemical activation by grinding on fibrosarcomas mill to a particle size of 0.5 - 5 μm, to prepare the molding paste is used dissolute natural clay, pasta, bring to a moisture content of 26 to 28%, the molding is conducted by extrusion through the die plate and receive the extrudate in the form of a graft or block cell structure, the final heat treatment is performed at 500 to 550°C. the Obtained product is used as the active catalyst in the process of selective reduction of nitrogen oxides with ammonia. 3 C.p. f-crystals, 1 table.

The invention relates to the field of chemistry, in particular to methods utilizationare closest technical solution to the claimed method is a method [RF patent N 2058190, B 01 J 23/745, 1994]. The known method is that the galvanic sludge and other background materials prepared by grinding in a disk mill to 50 microns, mixing the raw materials, preparing forming a paste by mixing with water, are formed through the mold, dried at a temperature of 25oC - 5 hours, 120oC - 15 hours to carry out heat treatment for 4 hours at a temperature of 800-900oC.

However, the known method does not allow:

a) waste disposed of copper-containing galvanic sludge,

b) to gain valuable end product, namely, a catalyst, active in the process of selective reduction of nitrogen oxides by ammonia,

C) has a complex technology forming the geometric shape of the starting materials and the preparation of the catalyst.

The invention solves the task of developing ways of disposing of galvanic sludge, allowing you to gain valuable final product in the form of a catalyst active in the process of selective reduction of nitrogen oxides by ammonia, waste disposed of copper-containing galvanic sludge that have the most optimal technology for the production of the catalyst.

The problem is solved by the preparation of molding paste, forming, final heat treatment, electroplating sludge taken from the content of main components in wt.%:

Fe2O3- 40-45,

CuO - 10-15,

Cr2O3- 5-10,

impurity - rest

additionally, conduct preliminary activation (thermal shock) at a temperature of 120-550oC and mechanochemical activation, the resulting product is used as a catalyst, active in the process of selective reduction of nitrogen oxides with ammonia. This mechanochemical activation is carried out by grinding on fibrosarcomas mill to a particle size of 0.5 - 5 μm, to prepare the molding paste is used dissolute natural clay, pasta, cook until moisture 26-28%, the molding is conducted by extrusion through the die plate and receive the extrudate in the form of a graft or block cell structure, the final heat treatment is carried out at a temperature of 500 to 550oC.

The technical result of the proposed solutions is to obtain a catalyst active in the process of selective reduction of nitrogen oxides with ammonia.

The proposed method of disposal of electroplating sludge is as follows.

Take prepared galvanic sludge is the optimum thermal activation at a temperature of 120-550oC, mechanochemical activation by grinding on fibrosarcomas mill to a particle size of 0.5-5 μm, to prepare molding paste, adding dissolute natural clay, bring the paste to a moisture content of 26-28%, spend the formation of the geometric shape of the extrusion-molded through a die plate, get the extrudate in the form of a graft or block cell structure, conduct final heat treatment at a temperature of 500-550oC.

The catalytic properties of the catalyst samples was determined on running the installation using the gas mixture composition, vol.%: Nox - 0,05, NH3TO 0.05, O2to 4.5. Volumetric gas flow rate 20000 h-1. Analysis of the gas mixture is performed with chromatographic methods. The degree of conversion of nitric oxide determined by the following formula

,

Testing of the catalyst is carried out in the temperature range 250-350oC.

To determine the mechanical strength of the extrudates are subjected to compressive crush strength in the transverse direction.

The essence of the method consists in the measurement of the efforts of the destruction of the granules between two parallel plates. The biggest strength of the catalyst is expressed in kilograms per square centimeter and rely on BR> S is a sectional area of the catalyst pellet, cm2.

The advantages of the proposed method:

1. Recycled tonnage of toxic waste electroplating plants, containing more than 10% of copper oxide.

2. In result of the utilization of obtained a highly active catalyst for the selective reduction of nitrogen oxides by ammonia.

The invention is illustrated by the following examples.

Example 1.

In the Z-shaped mixer load without preliminary preparation of 7.2 kg galvanic sludge containing wt.%: Fe2O3- 43, CuO - 11, Cr2O3- 7, the rest of the impurity add 2.8 kg dissolved Ob clay and 4.3 liters of water. The mixture is stirred until a homogeneous molding paste. Next, extrusion molding paste through a die plate to receive pellets with a diameter of 6 mm extrudates provalivajut at room temperature, dried at 120oC for 6 hours and calcined 4 hours at 500 - 550oC. the Obtained catalyst has a low mechanical strength and low catalytic activity (see table).

Example 2.

In the mixer load of 7.2 kg pre thermoactivation Gulf dissolved Ob clay. thermal activation of galvanic sludge is carried out by annealing the slurry at 500oC. the Rate of temperature rise in the range of 120-500oC for at least 250oC per hour.

The mixture is stirred at a constant addition of water until a homogeneous mass molding paste humidity 26-28 wt.%. Next, extrusion molding paste through a die plate to receive pellets with a diameter of 6 mm extrudates provalivajut at room temperature, dried at 120oC for 6 hours and calcined 4 hours at 550oC. the Obtained catalyst has a high mechanical strength, but has low activity in the process of selective reduction of nitrogen oxides with ammonia (see table).

Example 3.

In the mixer load of 7.2 kg pre-heat and mehanohimicheskogo galvanic sludge, containing, wt.%: Fe2O3- 43, CuO - 11, Cr2O3- 7, the rest of the impurity, 2.8 kg dissolved Ob clay. thermal activation of galvanic sludge is carried out by annealing the slurry at 500oC. the Rate of temperature rise in the range of 120-500oC for at least 250oC per hour. Mechanochemical activation is performed by grinding on fibrosarcomas mill to powder with the size of the receiving molding paste humidity 26-28%. Next, extrusion molding paste through a die plate to receive the pellets 6 mm in diameter and blocks cellular structure in the form of a prism of square cross section HH mm, the size of the channel 5,6x5,6 mm and a wall thickness of 1.4 mm extrudates provalivajut at room temperature, dried at 120oC for 6 hours and calcined 4 hours at 500 - 550oC. Obtain samples with high mechanical strength and activity in the process of selective reduction of nitrogen oxides with ammonia (see table).

Example 4 (for comparison).

Galvanic sludge, containing, wt.%: Fe2O3- 40, ZnO - 9 and NiO - 10, the rest of the admixture of oxides of manganese, vanadium, titanium, thermoactivated calcination at 500oC. the Rate of temperature rise from 120 to 500oC for at least 250oC per hour. Mechanochemical activation is performed by grinding on fibrosarcomas mill to a powder with a particle size of 0.5 to 5 μm. To thermo - and mechanoactivation powder add 2.8 kg dissolved Ob clay and water to obtain a molding paste humidity 26-28%. Next, extrusion molding paste through a die plate to receive pellets with a diameter of 6 mm extrudates provalivajut at room temperature, dried at 120oC for 6 hours and calcined is the process of selective reduction of nitrogen oxides by ammonia (see table).

1. The method of disposal of electroplating sludge with obtaining a catalyst comprising grinding sludge, the preparation of the molding paste using clay, forming and heat treatment, characterized in that the use of sludge containing, wt.%: Fe2O340 - 45; CuO 10 - 15; Cr2O35 to 10, which is subjected to additional thermal activation at 120 - 550oC, and then mechanochemical activation by grinding on fibrosarcomas mill to a particle size of 0.5 - 5 microns.

2. The method according to p. 1, characterized in that for the preparation of molding paste use dissolute natural clay, pasta, bring to a moisture content of 26 to 28%.

3. The method according to p. 2, characterized in that the molding is conducted by extrusion through the die plate and receive the extrudate in the form of a graft or block cell structure.

4. The method according to p. 1, wherein the final heat treatment is performed at 500 - 550oC.

 

Same patents:
The invention relates to sorption technique and can be used for air purification from toxic impurities in the means of respiratory protection, industrial adsorbers, etc

The invention relates to the field of chemical technology and can be used for purification of exhaust gases from hydrogen sulfide to produce elementary sulfur or for the production of elemental sulfur, for example, from natural gas companies gas, refining, chemical and other industries

The invention relates to compositions of catalysts intended for the oxidation of molecular nitrogen him oxygen compounds
The invention relates to the field of catalytic processes, in particular the production of a catalyst for the dehydrogenation of isoamylene in isoprene, and can be used in the production of synthetic rubber

The invention relates to the production of catalysts, namely the production of catalysts for the processes of dehydrogenation of olefinic hydrocarbons

The invention relates to the protection of the environment from toxic industrial emissions, and in particular to methods of preparation of catalysts for purification of exhaust gases from harmful substances

The invention relates to the production of heterogeneous catalysts for liquid-phase oxidation of sulfur compounds (sulfur dioxide, hydrogen sulfide, mercaptans) and can be used for purification of gas emissions and wastewater, energy, refining, petrochemical, chemical and pulp and paper industries
The invention relates to petrochemical synthesis, specifically to methods of producing N-methylaniline N-alkylation of aniline with methanol and can be used in the production of anti-knock additive to gasoline, in the manufacture of dyes and other products of organic synthesis

The invention relates to the production of heterogeneous catalysts for the intensification of oxidative neutralization of inorganic and organic toxic contaminants in the wastewater to the biological treatment stage and can be used in the petrochemical, refining, chemical, pulp and paper industries, as well as any other industrial plant with biological treatment plants

The invention relates to materials for the implementation of catalytic processes and can be used in chemical, petrochemical, light industry, in particular for the treatment of wastewater and gas emissions from sulphides

The invention relates to the production of carbon, preferably filamentous, and hydrogen from hydrocarbons

The invention relates to the field of chemistry, namely the preparation of catalysts for the combustion of fuel in the catalytic heaters

The invention relates to the field of catalytic combustion, namely the combustion of gaseous hydrocarbon fuel in the catalytic heaters

The invention relates to catalysts used in deep oxidation of hydrocarbons (afterburning of exhaust gases), partial oxidation of hydrocarbons (epoxidation of ethylene, propylene), alkylation of hydrocarbons, oxidation of sulfur dioxide in sulfuric acid production), hydrogenation (acetylene, nitrobenzene), the conversion of ammonia (nitrogen and hydrogen cyanide), etc

The invention relates to compositions of catalysts intended for the oxidation of molecular nitrogen him oxygen compounds

The invention relates to catalysts for deep oxidation of CO, hydrocarbons, soot, purification of vehicle exhaust and waste gases of industrial enterprises

The invention relates to catalytic combustion, and specifically to catalytic compositions for natural gas combustion
The invention relates to the field of cooking chromium catalysts used for a wide range of catalytic processes, for example, conversion, digidrive, origene, polymerization and other

The invention relates to catalysts used in the processes of conversion of ammonia (nitrogen and hydrocyanic acid), oxidation of sulfur dioxide (sulphuric acid), deep oxidation of hydrocarbons (catalytic heaters), mild oxidation of hydrocarbons (e.g., the production of formaldehyde from methanol), clean automobile and industrial emissions (burner exhaust gases), etc
Up!