SU1700100A1 - Method of manufacturing titanium dioxide-manganese anode - Google Patents

Abstract

The invention relates to electroplating, in particular to methods for producing anodes for the chromium plating process, and improves the quality of manganese titanide oxides for improving the electrical conductivity and mechanical strength. A method of manufacturing a titanium stanchion margins anode involves treating a titanium base with a solution of a tin compound and heat treatment followed by repeated deposition of layers of manganese containing compound and annealing. As a manganese-containing compound, a manganese nitrate acid melt containing 10–12 wt.% Of tungsten carbide and a net titanium base substrate is used, with each subsequent manganese dioxide layer applied with layers of carbon fiber with a mutually perpendicular arrangement of the filaments in table 2.

Description

The invention relates to electroplating, in particular to chrome plating processes.

The aim of the invention is to improve the quality of a titanium-manganese anode by improving its electrical conductivity and mechanical strength,

The method is carried out as follows.

1.In an enamelled vessel, installed on a thermostatted sand bath, the required amount of manganese nitrate is placed and at 90-100 ° C is first subjected to degreasing, then melted (150-180 ° C), while not allowing the release of nitrogen oxides.

2. The titanium base is ready and the mesh form is 1-2 mm in diameter and the filament is 1.0-1.5 mm in thickness in the following sequence: clean the surface with quartz sand / zpek-with corundum; degrease chemically. electrochemically; activated in a concentrated solution of sulfuric acid; treated (by willowing or brushing) in solution with concentrated sulfuric acid in butyl alcohol in a 1: 5 ratio with the addition of SnCl4 5H20 10 g for every 35-40 ml of solution; dried at 120 ° С and then burned at 600 ° С (25-30 min).

3. Lay a titanic grid and the pallet (baking sheet) from stainless steel with the smooth bottom.

4. Enter tungsten manganese nitrate manganese nitrate (WC) with a dispersion of not more than 10 microns at a rate of 10-12 wt.%, Mix thoroughly and obtain SXI

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The drench is applied over the titanium mesh base.

5. Remove the grid from the pallet and subject it to annealing at 400-450 ° C in air (until the allocation of the books of nitrogen oxides stops).

6. Lay a carbon fiber layer from both sides of the titanium base with mutually perpendicular arrangement of the threads so that they form a mesh frame with a cell size of not more than 5.

For this purpose, a carbon fabric knit fabric URTL-250 can be used, the patch of which is drawn around the skin: a direction perpendicular to the extended L loop paths forms a grid with a mesh size of 1-2 mm. Repeat operations 4, 5 to obtain a layer of active mass of 4-5 mm, and each process, before applying the suspension, perform step 6.

PRI me R 1 (prototype). It is carried out with the performance of operations 1-5 according to the above scheme in the absence of manganese nitrate and aolfrism carbide in the melt and a threefold repetition of operations 4, 5.

EXAMPLE 2. Performed in steps 1-5 according to the above scheme and repeating operations 4, 5 three times.

Example 3. Carry out the execution of operations T - 5 on the basis of the schemes and the triple execution of operations 4, 5,

The tests were carried out in pilot-scale conditions with the use of anodoses of sizes 50x120: m and a total thickness (base and active mass) of an average of 5-6.5 mm. To protect the lateral and face faces of the anode from shock and damage, it is placed in a PTFE-type Teflon frame.

The criterion for evaluating the method is the electrical conductivity of the mechanical resistance of the active mass obtained according to the examples. Measurement of the electrical conductivity of the ECHTMBN mass executing the north-south with the help of the bridge М-305.

Mechanical resistance was determined by a non-standard procedure on samples with a length and width of the section with an active mass of 50 v 20 mm, respectively. The thickness of the active mass on each side of the titanium mesh base is 2.5 mm on average. The ends of the latter are preliminarily (before applying the active layer) titanium plates psawg rhom 25x20x1.5 mm, free from the active mass, are soldered. the surface of the opposite end face of the sample asks-ups an eccentric attached to the hall

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motor, the magnitude of the amplitude deviation due to eccentricity during rotation of the motor shaft is 3 mm at a frequency of deviations of 60 beats / min and a test cycle duration of 10 minutes. Mechanical stability is determined by visual inspection of the nature of the active damage, the test results are presented in Table. one.

The range of test results shows that the proposed method provides for obtaining tigzdvuokisno-manganese a :: odo, characterized by much higher values of electrical conductivity and mechanical durability compared with the known (example 3). This is achieved by creating a uniformly distributed volume of the active mass, solid particles of tungsten and carbon particles, which ensures a sharp decrease in the electrical resistance of the material and an increase in its mechanical stability. The evidence of this is, and, a high value of specific conductivity of tungsten carbide and carbon fiber, which are in the range of 0.1-0.3 103 and 3-5 - 1C3, respectively.

Ј Table 2 presents the results of studies of the dependence of the electrical conductivity and mechanical strength of the active mass on the content of the dispersed phase of arb / gdz tungsten in the maog nitrate melt; hzs (in the absence of carbon oxide in the coating and other unchanged parameters).

The results show that the specified limits of tungsten carbide in concentration (10-12%) provide optimal characteristics of the active mass of manganese dioxide. Thus, the increased content of the dispersed phase increases i /.;-, Kv, -) npor. active mass, but,: ..; oci, (T at the same time to the disruption of melodious stability due to increased brittleness and mechanical, breeding tendency.

In the manufacture of titanewoxide-manganese anodes of the proposed method, the porosity of the active mass is reduced from 15-25%, and in the known methods to 8-12%; as a result, its chemical resistance increases. This is indicated by the immediate assessment of the state of the anodes, made accordingly according to the example. Paradise 1 and 3 after their anodic polarization are narrower, e 400 h (the nominal time is taken into account) by the process of chromium plating of parts from the electrolyte, g / l: chromic anhydride 200,

sulfuric acid 2.5 at a temperature of 70 ± 2 ° С and anodic current density of 15 A / dm.

On the anodes made by the proposed method, no changes in the surface layer of the active mass were found, while on the anodes made in a known manner, separate foci of pitting corrosion and weak surface destruction were observed. In the electrolyte, the presence of manganese was detected up to 0.03 g / l.

Claims (1)

The invention of the method for the manufacture of titanium and manganese anode for chrome baths0 TO This includes the processing of the titanium-1 mesh base in a solution of a tin compound, heat treatment and the subsequent repeated application of manganese nitrate and annealing, which differs in that. that, in order to improve the quality of the anode due to the improvement of electrical conductivity and mechanical durability, when applied, a manganese nitrate melt containing 10–12 mcc.% tungsten carbide is used, and prior to the application of layered manganese to the base of each successive layer, voto zo mutually perpendicular arrangement of R layers. Table 1 table 2