Selenium and tellurium are extracted from anode slag for copper refining

Prior to this, there was approximately one component of anode slag. Up to 70% of the ingredients are in the form of metals, with the rest in the form of oxides, sulfides, selenium and tellurides. The copper is detached from the electrode in the form of a large crystal and appears as a fine powder, produced by an oxidation reaction -- restoring a single copper:

This is a Cu + Cu2 + that is indicated by the 2Cu.
Copper also contains copper sulfate, oxide, copper sulfide, and copper selenide.
Depending on the sludge, the main content of the application of a variety of circuit gold and silver processing. However, in all modern diagrams, the first operation is to remove the copper from the sediment -- to remove the sediment.

Slag purification and desalination

Originally, the silt was sifted through large sieves to remove copper fragments and foreign pollutants. The mud is then washed many times with hot water. In this case, the sewage contained copper sulfate. Solution filter sludge drying and screening thin city office main media and quartz crystal sand. Branches of the latter are sometimes produced in rising flowing water, which carries less weight in sand.

Sulfuric acid solution (3-15%) is made from sulfuric acid solution (3-15%). Chen Da Lu Tong lead and lead solution are heated to 70° when the coil and dissolved air are oxidized after media purification. Accelerated dissolution of sludge is sometimes subjected to a pre-oxidized roasting temperature of 300-370 °.

Selenium may be transferred to a solution when the scorched residue is dissolved in sulfuric acid. It must settle again. This is achieved by boiling water and excess copper. However, Selena's reaction was:
2Cu + H2SeO3 + 2N2SO4 + 2Cuso4 + SE + 3N2O.
sludge after cleaning and drying for further processing. Ash removal removes 70 to 80 percent of the copper.
Anode slag treatment method
In the modern industrial practice recycling sludge is usually divided into two phases:

The first phase consists of preparatory work aimed at removing most of selenium (or selenium and tellurium) and enriching the slag with precious metals.

The second stage is the smelting of gold and silver alloys by oxidized sludge.
To extract selenium and tellurium and prepare the mud on the metal, use oxide burns, sulfuric burns and baking soda residue.
Slag roasting

Aye Gayev studied the cinder burning process in detail. Oxidizing roasting in sludge, oxidation of basic base metals copper, selenium and tellurium, and selenium and tellurium in a conductive reflector at 600-700 ° C. The main reactions of selenium acidification are as follows:

Cu2Se + 2O2 = CuSeO3 + CuO;
Cu2Se + 2O2 = 2CuO + SeO2;
So Ag2Se plus O2 is equal to 2Ag plus SeO2.

At the same time, but much more slowly, Trulida oxidizes. When the kiln SeO2 image TeO2 п ы л е л а kind guide л и kind guide а detection system. Finally, the accelerated roasting temperature rose to 750-800. Under factory conditions, dust of 85-90% selenium can be extracted from slag containing 12-16% Se, and the soil content removed from the slag is much lower. In addition to SeO2, the captured dust contains water-insoluble selenate FeSeO3, CuSeO3, PbSeO3 and Cu2Se. Part and basic mode of recovery of copper sulphate sulfur dioxide reaction products.

Sour slag roasting
This method heats the sludge with concentrated sulfuric acid. с л ь ф а т и з а ц mechanization of muffle furnace at f р е б seem о kind guide vehicle supplies. The initial process results in a temperature of 150-300 °. Simultaneous copper, selenium and tellurium acidification:
Cu 2 + 4 = CuSO4 h2s О SO2 + 2 + 2 Н О;
Se + 2 h2s О 4 = SeO2 + 2 s О 2 + 2 Н 2 О;
Te h2s О 4 + 2 + 2 = TeO2 so2 Н О 2 + 2.
And then the temperature goes up to 400 to 500 degrees. Most drilling SeO2 see sublimation, and most T е O2 in sludge.

With the sludge for extraction of copper sulfate kind guide ы щ е л а discusses some related problems и kind guide а water, extracting tellurium and caustic soda solution. After drying, the filter sludge flows into the metal smelting expensive.

This method yields a higher recovery of selenium and tellurium than oxidative calcination.

You can use baking soda for the sludge

In the oxidized atmosphere, selenium and some telluride slag are oxidized to produce water-soluble selenate and sodium ferrite:
Se + Na2CO3 + O2 = Na2SeO3 + CARBON dioxide;
Te plus Na2CO3 plus O2 is equal to Na2TeO3 plus CO2
It can be produced at muffle furnace temperature of 500-600 ° C. Speck selenium and tellurium extracting kind guide ы щ е л а discusses some related problems и kind guide а water. Then the silt goes into the molten metal DORA.

Boron smelting of metal
In one of the above preparations, after desalination, it is melted into a reverberatory furnace (rice). 227).
Selenium and tellurium are extracted from anode slag for copper refining
Before that, the silt was mixed with quartz sand and soda (equivalent to 10 to 12 percent of the slag's weight). Shihtu is an oxidant (5% of mud weight). Smelting requires a temperature of about 1300° C. The sides and sides of the furnace are made of magnesia bricks, and the vault is made of dynastic or magnesia bricks. The capacity of the furnace is 5-10 tons.
Once the mud melts, the surface of the tub produces silicate slag, which consists of silicates, weapons stores and antacids. Up to 30% of the weight of the SHichta.
Once the silicate slag is released, the bath water is drawn into the air, oxidizing the mixture of nitrate and carbonate into the more complete sulfate.
The other is soda ash, which converts the basic amount of selenium and tellurium into Na2SeO3 and Na2TeO3. When nitrate oxidation is complete, the metal content is 96-98% Au and Ag.

The yield of soda ash is about 15% of shichta's weight.

In the melting process, parts of selenium and tellurium are vaporized and captured from the dust catcher. On the scoreboard. Chemical composition of 91 different products.

Selenium and tellurium are extracted from anode slag for copper refining
The following is the distribution of selenium (as a percentage of total slag) in the aye Gaeva data:
Selenium and tellurium are extracted from anode slag for copper refining
These data indicate that the main sources of selenium are dust and solution in the dust removal system. Part of the selenium is in the slag.

Data scoreboard. Tellur was shown to be more concentrated in soda ash than selenium.

The gases of the roasting and melting furnaces pass through a dedusting system consisting of a dedusting chamber, cyclone, Scrubb, irrigation, and a wet-electric filter. 228).


Dust removal system slag treatment

The dust removal system (irrigation tower and hydro-electric filter) contains selenium and tellur and mainly exists in the form of SeO2 and TeO2, which are either watered or filtered after the scrubber and hydro-electric filter. Leaching temperature of 50-60 ° leads to good relationship: after t = to 1 п р о д kind guide dissolved air. At the same time, SeO2 is soluble in selenium acid H2SeO3. The concentration of selenium in the solution is about 100 g/L.
The soil dioxide is insoluble in water and remains in a solid residue, which is extracted with a corrosive solution. Sodium telluride is a solution of Na2TeO3.
In almost all water alkalization, the bulk of selenium remains an insoluble residue. This is because with the addition of SeO2 and TeO2, a mixture of other elements such as iron, copper, lead, SO3 and SO2 is thrown into the dust.
Due to the interaction of selenic acid with these compounds, reactions insoluble in selenium (Trulite) and selenium (Trulide) may occur. In addition, basic selenium (Trulla) may be produced by the action of reducing agent (SO2 etc.).
Therefore, additional acid desalination is usually required to prevent water from desalting 15-20% of sulfuric acid.
If there is selenium and telluride KMnO4 acidic oxidant (HNO3 before processing production, etc.).

Slag, selenium and tellurium in sodium also kind guide ы щ е л а discusses some related problems и kind guide а chopped water. At the same time, Trure and Salem became the solution (rice) together. 229).

Selenium and tellurium are extracted from anode slag for copper refining
After the sulfuric acid is neutralized and the solution reaches a pH of 6-6.5, the boiling water in the solution is surrounded by diluted soil dioxide and then dissolved in the corrosive Natra solution. Leaching results, therefore, to obtain separate с е л е н с о д е р ж а т е л л р с о д е р ж а solution.
Separate selenium from solution

Selenium is usually formed by deposition in a solution containing selenic acid and sulfuric acid, which is easy to reduce selenium compounds to metals by reaction:
H2SeO3 + 2SO2 + H2O = Se + 2H2SO4.
Here is one of the available siege modes. Deposition (2% HCl) solution to acidification at a temperature of 15-30 °. SO2 passes through the solution (rice) in a few hours. 230).

Selenium is surrounded by an amorphous red powder. Then at 90° the solution was heated for 1 hour to translate sitting in the red series of amorphous crystals. The obtained technique selenium is crushed as bark and transferred to refining if necessary. Technical selenium usually contains 2% of impurities, including 0.01 to 0.1% Te.
In the presence of selenium and tellurium, the acidity of the solution can be adjusted to form layered deposits (see figure). 217).
Sulfuric acid reduction with HCl concentration higher than 27%, while H2SeO3 hardly occurred. The original highly acidic solution surrounded the village and then diluted the solution to produce special tellurium.
Selenium and tellurium are extracted from anode slag for copper refining
Technical selenium refining
The elastic values of the following pair of selenium at different temperatures indicate that the technology selenium can be purified by distillation.
Selenium and tellurium are extracted from anode slag for copper refining
Distillation is carried out at 650-68 ° under atmospheric pressure. At low pressure (2-5 mm). St) Can produce 350-400 ° during surgery. In cast iron the distiller (rice) is carried. 231). The refined selenium bars are being slowly cooled so they can be grayed out.

After one distillation, its content drops to 0.02%, and after two distillation, it drops to less than 0.01%.
Get the tellurium

Recovery of carbon dioxide tellurium powder or electrolysis by a method suitable for metallic tellurium.
Reaction of carbon powder at 500-600 ° C after water leakage:
TeO2 + C = Te + CO,
These methods yielded tellurium 98.5%, a total of 97-TE.

Due to the toxicity of trulla compounds, the disadvantages of this method are large losses and poor service conditions.

More convenient electrolytic methods describe various acid and alkaline electrolyte baths.

Here is the basic electrolysis model developed by Artificial intelligence Geyev, artificial F. Grekov, and V. M. Schur.
Electrolysis leads to an alkaline solution containing 100 g/L Te free caustic soda and 160 g/L. The electrolyte of this compound has very little resistance.
Selenium and tellurium are extracted from anode slag for copper refining
The electrolysis is carried out in a 25 litre glass bath with IXI8H9 stainless steel electrodes.
Since tellur is powder based, they put the electrodes in a bag to make it easier to unload them.
Trulla powder is rinsed with water, then with alcohol, and then produces a dry powder, such as hydrogen, in the reduced atmosphere.
It consumes 3.6 kilowatts of electricity per kilogram of telula; The current output is 88%, and trulla's dioxide technically produces 98% of the metal.


 

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