RU2113518C1 - Apparatus for extracting metal ions out of aqueous solutions - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: apparatus is in the form of horizontal drum mounted with possibility of rotation. Wings for agitating scrap are secured to inner surface of said drum. Apparatus includes magnets for coagulating ferrites, drive mechanism, grid preventing scrap removal, charging and discharging devices. Inner cavity of drum is divided by two halves with the aid of apertured partition. Charging may be realized into both halves of drum. EFFECT: enhanced efficiency. 1 dwg , 1 tbl

Description

 The invention relates to the field of metallurgy of non-ferrous metals and can be used for wastewater treatment.

 Known devices for the extraction of metal ions from aqueous solutions by their treatment with colloidal iron hydroxide (Babenkov ED Water purification by coagulants. - M .: Nauka, 1977, S. 244-248).

 However, these devices are not applicable for the separation of noble metal ions, for example, gold, silver, as they do not provide the deposition of these metals from cyanide solutions.

 A device for extracting noble metal ions from aqueous solutions is known, comprising a drum provided with shelves located on its inner surface. The drum also contains a grid, drive, loading and unloading devices (ed. St. USSR N 380728, class C 22 B 15/12, 1969).

 The disadvantage of this device is the length of the process of extracting ions from their aqueous solutions, low productivity of the device.

 Closest to the proposed one is an apparatus consisting of a horizontal rotating drum made of dielectric material and lined with copper (ed. St. USSR N 841369, class C 22 B 11/12, 1980).

 Inside the drum are longitudinal perforated shelves made of dielectric or copper. The apparatus is equipped with an inlet and outlet mouths for loading scrap, removing the resulting ferrite, supplying and discharging the solution, as well as providing drum ventilation during continuous operation of the device. The device is divided by a mesh that prevents the removal of scrap. The drum is mounted on the support rollers and is driven into rotation by the support and support rollers.

 However, the known apparatus has a number of significant drawbacks. So, for example, the design of the apparatus ensures that scrap is loaded into it only on 1/3 of the internal (working) volume of the drum, which negatively affects the performance of the metal extraction process.

 Another significant drawback is the periodicity of the process of extraction of metal ions from their aqueous solutions. The frequency of the process is due to the fact that when the drum rotates, the scrap is carried away by the shelves and removed from the fluid that comes to be cleaned. The extraction process starts again at the moment when, under the influence of gravity, the scrap falls from the shelf down and thus falls into the liquid. As a result, scrap is stored periodically in the liquid being cleaned and its amount varies from almost complete absence to a maximum equal to the load.

 The aim of the invention is to increase the productivity of the apparatus.

 The goal is achieved by installing in the drum a horizontal supporting perforated plane dividing the internal volume into two equal parts. The plane is rigidly connected to the side walls of the drum.

 The essence of the invention lies in the fact that in the proposed invention, the scrap is loaded into the drum both on the supporting perforated plane and under it. Double the amount of scrap loaded into the drum increases the performance of the apparatus due to the establishment of the continuity of the process of water purification from metal ions.

 The continuity of the process is due to the fact that when the drum rotates, the scrap is carried away by the shelves and is taken out of the liquid entering for cleaning. However, how much scrap is removed from the liquid, the same amount of it comes in again at the same time as the carrier plane with the scrap is immersed in the liquid to be cleaned. The latter is associated with a waltz, in which partners gradually change their places with each other.

 The novelty and significant differences of the claimed technical solution lies in the fact that the new structural element allowed to increase the loading of scrap and caused the continuity of the cleaning process.

 The drawing shows a diagram of the proposed apparatus, section.

 The apparatus consists of a horizontal rotating drum 1 made of dielectric material and lined with copper 2. Inside the drum are longitudinal perforated shelves 3 made of dielectric or copper. The apparatus is equipped with an inlet 4 and unloading 5 necks for loading the scrap, removing the formed ferrite, supplying and discharging the solution, as well as providing ventilation inside the drum. The apparatus has two cleaning zones: the formation zone 6 and the enlargement of 7 ferrites, equipped with magnets 8. The zones are separated by a vertical grid 9, which prevents the removal of scrap. The apparatus drum is mounted on the support rollers 10 and is driven into rotation by means of rollers 11. The known device is additionally equipped with a horizontal perforated metal plane 12 or a plane of a dielectric lined with copper.

 The operation of the apparatus is as follows.

The apparatus 1 is loaded through the inlet neck 4 with copper and iron scrap. It is loaded in the required quantity onto the supporting perforated plane 12. Then the drum is rotated 180 ^° and the loading operation is repeated. As a result, the drum contains two scrap loads, one of which is placed on the supporting perforated plane 12, and the other under it. The fill factor with a scrap of the inner volume of the drum above and below the perforated plane does not exceed 0.7-0.8. The rotation of the drum contributes to the mixing of the scrap and its alternate contact with oxygen.

 The initial solution containing metal ions enters through the neck 4 into the drum 1 into its lower part 3. The contact of the scrap placed in the lower part of the drum with the liquid being cleaned is accompanied by the formation of a copper - iron or graphite - iron galvanic pair. During electrochemical corrosion, iron scrap undergoes anodic dissolution. The rotation of the drum leads to a gradual exchange of scrap in places: the lower part of the drum occupies the upper position and vice versa. In this case, the scrap is in the upper position, and the liquid flows through the perforated plane and irrigates the scrap that has moved there. The process of anodic dissolution of iron with the formation of a coagulant as a result of rotation of the drum with scrap proceeds continuously.

 Magnets 8 at the discharge end of the drum prevent the rapid removal of dispersed ferrite from the drum zone and contribute to its enlargement. The water purified from metal ions is removed through the discharge neck into a sump to separate the sediment.

Example 1 (prototype). Crushed graphite with iron shavings (for the formation of a galvanic pair) in the amount of 0.5 and 1.5 kg, respectively, is loaded into a drum with a working zone volume of 0.008 m ³ .

For cleaning, a solution is used containing, mg / l:
Zn ⁺² - 2.92
SO $\genfrac{}{}{0ex}{}{\text{-2}}{\text{4}}$ - 96.4
Ca ⁺² - 64.1
Pb ⁺² - 1.42
Fe ⁺² - 1.65
The experiments were carried out at room temperature 20 ^o C. the Duration of processing the solution in the apparatus 1 h. The rotation speed of the drum 11 rpm The results of the experiment are presented in the table.

 Productivity of the device is 100 g of solution per hour.

 Example 2 (prototype). In the conditions of example 1 was treated with water containing 500 mg / l of zinc and the same amount of lead. The results of the experiment are presented in the table.

 Example 3. In experiment 1, on a perforated plane placed in the grooves inside the drum, 2 kg of scrap containing 0.5 kg of graphite and 1.5 kg of iron chips are evenly placed on its surface. Space fill factor 0.62.

After turning the drum 180 ^o on a perforated plane placed another 2 kg of the above scrap. Processing time 30 min. The results of the experiment are shown in the table.

 Example 4. In the conditions of experiment 3 was treated with an aqueous solution containing 500 mg / l of zinc and lead. Processing time 23 min. The results of the experiment are shown in the table.

 Example 5. In the conditions of experiments 3, 4 were treated with an aqueous solution containing 500 mg / l of zinc and 500 mg / l of lead. The loaded scrap contained 1.5 kg of iron and 0.5 kg of copper shavings. The results of the experiment are shown in the table.

 From the results shown in the table, it is seen that in the presence of a double amount of scrap, the process of purification of water from metal ions is completed in 30 minutes, while under the conditions of the prototype it is necessary to spend at least 1 hour. Comparative data of experiment 5 and experiment 4 show the possibility of cleaning with various galvanic vapors (graphite-iron or copper-iron) with the same positive effect.

 From these experiments 1-5 it is seen that the goal set in the invention is to increase the productivity of the apparatus - is achieved.

Claims (1)

 An apparatus for extracting metal ions from aqueous solutions, containing a horizontal cylindrical drum, shelves located on its inner surface, a drive, a grid, loading and unloading devices and magnets, characterized in that it is equipped with a longitudinal perforated partition installed in the drum with the separation of its internal volume in two equal parts, the loading device is configured to provide loading in both parts of the drum.

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