SU1252057A1 - Apparatus for electrochemical producing of powders - Google Patents

Description

The invention relates to powder metallurgy, in particular to devices, the electrochemical production of powder from wastewater, and can be used for the treatment of silver from waste fixing solutions and washings.

The purpose of the invention is to increase the processing speed of metal-containing solutions.

FIG. 1 shows the scheme of the proposed device, a longitudinal section; in fig. 2 is the same cross section.

The device for the electrochemical production of powder consists of an electrically conductive body 1, a two-core rod drum 2 consisting of end walls 3 fastened with clamps 4 which contain conical rods 5 and between which are located the rods of the outer 6 and inner 7 rows, anode 8, a collection of silver powder, made in the form of a removable cup 9 with locking KJianaHOM 10 CYCLES, lugs 11, serving them to force the rods of the outer row 6 of the drive 12, rotating the rod drum 2, the pump 13, to rotate the current circulating solution through the non-conducting body 1, the electrical power supply node 1A and the cathode drum, the flow distributor 15, the pipeline 16, the lever 17, designed to maintain contact of the electrical power supply node 14, the partitions 18 that control the flow and allow separating chipping particles powder. At the same time, the rods of the outer row 6 are set circumferentially with a diameter D, 15-100 times greater than the diameter (d) of the electrode bodies, the rods of the inner row 7 - circumferentially with a diameter D, (0.5-0.75) D, and the diameter of the rods is 1.5-2 diameters of the electrode bodies,

The device works as follows.

The drive 12, including the asynchronous motor and the drive shaft, by means of a V-belt transmission (shaft and gear are not indicated) ensures rotation of the two-rod rod drum 2 with movable electrode bodies (not indicated) around the horizontal axis. Using a centrifugal pump 13, parts of which are made of non-metallic materials, a pipeline 16 and a flow distributor 15, designed as a perforated tube located in the lower part of the nonelectrode housing 1 parallel to the axis of the drum core 2, forces the electrolyte through the housing 1. Due to the high current load (up to 100 A), rapid precipitation occurs; the metal powder is applied to the electrode bodies and rods of rows 6 and 7.

Due to the low surface current density, due to the presence of a highly developed cathode surface (electrode bodies), as well as the intensive circulation of the solution, the metal is extracted to low residual concentrations. Due to the intensive hydrodynamic regime created by the rotation of the core of the drum 2 and the constant movement of the electrode bodies, intense spallation of the precipitated powder occurs both from the cathode rods of rows 6 and from the electrode bodies. The shear sediment under the influence of gravity and the flow of the solution is entrained in a calm zone in the lower part of the housing 1, separated from the flow by means of partitions 18 and collected in a removable cup 9 of the powder collector. In this case, the locking valve 10 occupies the upper position, in which between its lower edges with a seal and the bottom of the device body 1 there is a gap through which metal particles penetrate into the removable cup 9. The sludge is unloaded without stopping the electrolysis process, for which the C7 earth cup 9 is taken out through the bottom opening of the collector, and the locking valve 10 lowers and closes the upper opening (not indicated) of the collection

In this case, the ratios of the diameters of the rods of rows 6 and 7 and the electrode bodies determine the operability of the drum 2. The minimum diameter of the rods d, equal to 1.5 times the diameter (d) of the electrode bodies, is determined by the conditions of their strength and the capture efficiency of the electrode bodies during rotation. the drum. Going beyond this limit is accompanied by a worsening of the conditions for spallation of the sediment and a decrease in the processing speed

At d (2d), the mobility of the electrode bodies relative to each other decreases and the conditions for their capture during the pouring process deteriorate, which reduces the intensity of spallation of the sediment and leads to a decrease in the processing speed of the solutions.

The ratio D, / d is determined by the condition of the pouring of the electrode bodies and its influence on the cleavage intensity of the silver deposit. With

D // d

15 reduced mobility

electrode bodies inside the drum, which makes it difficult for them to collide, worsening chipping, and reduces the processing speed of the solutions. In the case of D, / d 100, the spallation of precipitated silver worsens due to a decrease in the strength of mutual collisions of the electrode bodies between themselves and with the drum rods, caused by hydrodynamic drag.

The ratio Dj / D– (0.5–0.75) determines the conditions for intensive spallation of sediment from the electrode bodies and rods of the inner row in the central zone of the drum.

o

five

0

five

With the ratio P, / D 0.5, the rods of the inner row are not sufficiently deeply immersed in the array of electrode bodies and do not contribute to intensive mixing of the latter, which worsens the spallation of the sediment and reduces the processing speed of the solution.

The ratio, 0.75, creates a zone of low-mobility electrode bodies in the central part of the drum and makes it difficult for the sediment to peel off in the peripheral layers of the electrode bodies, reducing the processing speed of the solutions.

The results of the proposed device, having cathode drum dimensions equal to Djap- 300 mm and L, ap 400 mm, in comparison with the technical characteristics of the prototype are presented in the table.

Testing is carried out with the extraction of silver from the fixing solution with an initial metal concentration of 1.5 hum. The volume of the body is 100 liters, the diameter (d) of the electrode bodies is 15 mm, the fill factor of the drum volume by bodies is 0.7. The current load in all experiments is 100 A.

2

Claims (1)

DEVICE FOR ELECTROCHEMICAL POWDER POWDER, including a non-conductive housing, a horizontal rotating cathode made in the form of a core drum with movable electrode bodies, an anode, a pump for holding solutions, the core drum is double-row, the rods of the outer row are kinematically connected with stops and mounted around the circumference diameter D ₍ , 15-100 times greater than the diameter of the electrode bodies, the rods of the inner row - on a circle with a diameter of D ₂ equal to (0.5-0.75) D _<f and the diameter of the rods is 1.5-2 diameter of the electric one body, while the drum is equipped with conical rods mounted on its end walls with the possibility of axial rotation, and the powder collector is made in the form of a glass with a locking valve. Fy * t SU <„, 1252057 * 125