Ilana fun Imularada Acidification ti iṣuu soda Cyanide ati Awọn irin Heavy lati Omi Egbin

INiṣafihan

omi idọti ti o ni cyanide is generated from various ise lakọkọ bi eleyi Iwakusa wura, itanna, Ati iṣelọpọ kemikali. Nitori awọn Oloro to gaju of cyanide, improper discharge of this wasteomi le fa àìdá Agbegbe ayika and harm to Ilera Eniyan. Therefore, the treatment and resource recovery of Omi Idọti ti o ni Cyanide have become crucial issues. Among the Awọn ọna itọju, Acidification Ìgbàpadà of Iṣuu soda Cyanide ati eru awọn irin is a widely used and effective approarakunrin, which not only reduces the Ewu Ayika but also realizes the recycling of valuable resources.

TitẹCIPle ti Acidification Ìgbàpadà

Iyipada ti cyanide si Hydrogen cyanide (HCN)

ni awọn acidification process, Acid ti o lagbaradabi imi olomi ti wa ni afikun si awọn Cyanide-containing wastewater. Under acidic conditions, cyanide ọfẹ ions in the wastewater transform into Hydrogen Cyanide (HCN). hydrogen cyanide is a volatile compound. When the pH of the wastewater is adjusted to a low value, usually below 2. the lenu is more likely to proceed, faCILitaTinahg the conversion of ions cyanide into HCN gas.

Imularada ti iṣuu soda cyanide

The generated HCN gas is then introduced into an alkali absorption tower. Inside the tower, it reacts with a iṣuu soda hydroxide (NaOH) solution. As the reaction proceeds, iṣuu soda cyanide (NCN) is formed and accumulates in the absorption solution. When the concentration of NACN in the solution reaches around 10% - 12%, it can be recycled and reused in relevant industrial lakọkọ, gẹgẹbi awọn leaching ilana in Iwakusa goolu.

Release and Precipitation of H.E.A.vy Awọn irin

Besides free cyanide, the wastewater often contains complexes of heavy metals and cyanide, like those of Ejò ati sinkii. Under acidic conditions, these complexes break down. Once the heavy Awọn ions irin are released, they can form intiotuka salts and precipitate under specific conditions. For example, adjusTinahg na pH iye or adding certain Precipitating Aṣojus can cause Awọn ions Ejò to form precipitates.

Awọn Igbesẹ ilana

Step 1: Wastewater pretreatment

awọn ipilẹ cyanide - containing high - concentration wastewater first passes through a sTIIm heat exchanger to control its temperature. Typically, the temperature is kept within the range of 20 - 25°C. This temperature control helps optimize the subsequent reaction rate and ensures the iduroṣinṣin of the process. The concentration of cyanide in the high - concentration wastewater generally ranges from 5000 - 5500 ppm, and the pH value is between 10.5 - 12.5.

Igbesẹ 2: Acidification

The pre - treated wastewater is fed into an acidification spray tower at a certain flow rate, for example, 2 m³/h. Then, sulfuric acid ogidi is added. The amount of Efin imi-ọjọ added is adjusted according to the characteristics of the wastewater, generally 25 - 30 kg/m³, to lower the pH value of the wastewater to less than 2. The heat released during the addition of Acid Sulfuric can speed UP the reaction, MAking it easier for free Awọn ions Cyanide in the wastewater to turn into volatile HCN.

Step 3: HCN Generation and Iyapa

In the strongly acidic ayika of the acidification spray tower, the conversion of cyanide to HCN is promoted. The formed HCN gas is then drawn by a vacuum centrifugal fan and enters the next stage - the alkali absorption tower. At the same time, as the pH value decreases, some heavy metal ions in the wastewater start to change. For instance, the concentration of Ejò ions in the wastewater may drop, and some heavy metals begin to form precipitates.

Step 4: Absorption and Recovery of Iṣuu soda Cyanide

The HCN gas enters the alkali absorption tower and is absorbed by a 20% - 30% NaOH solution. The alkali absorption liquid in the tower is recycled, and during the recycling process, a fan is used to ensure the HCN gas is absorbed repeatedly. As the absorption reaction continues, the concentration of Nacn in the absorption liquid gradually increases. When the NaCN concentration reaches 10% - 12%, it can be returned to the Ilana Leaching for reuse, thus achieving the recovery of iṣuu soda cyanide.

Step 5: Heavy Metal Precipitation and Iyapa

For the wastewater after the release of HCN, since some heavy metal - cyanide complexes have been broken down under acidic conditions, further treatment can be carried out to precipitate heavy metals. For example, adjusting the pH value of the wastewater to an alkaline range can form heavy metal hydroxides that precipitate. Then, solid - liquid Iyapa awọn ọna bii ase or Idaduro can be used to separate the precipitated heavy metals from the wastewater, achieving the removal and recovery of heavy metals.

Awọn anfani ti Ọna Imularada Acidification

Atunlo orisun

The acidification recovery method can effectively recover iṣuu soda cyanide lati Cyanide - ti o ni omi idọti, which can be reused in relevant industrial processes, reducing the agbara ti titun iṣuu soda cyanide ati sokale Iye iṣelọpọs. At the same time, heavy metals can also be recovered, turning waste into valuable resources.

Iye owo - ṣiṣe

Compared with some other treatment methods that only focus on destroying cyanide, the acidification recovery method not only treats the wastewater but also recovers valuable substances. Although it requires the consumption of acid and alkali, the value of the recovered soda cyanide and heavy metals can offset part of the treatment cost, making the overall treatment more cost - effective in the long run.

Firanṣẹironmental Friendliness

By recovering soda cyanide and heavy metals, the amount of pollutants in the wastewater is significantly reduced. The treated wastewater has a lower content of cyanide and heavy metals, which is more conducive to subsequent discharge or further treatment, reducing the negative imPACt on the environment.

Lilo ni Acidification Recovery Ilana

The consumption of the acidification recovery method for cyanide - containing wastewater mainly includes sulfuric acid, Omi onisuga caustic (NaOH), Orombo wewe, and electricity. In winter, it is necessary to preheat the wastewater, so steam is also consumed.

1.Acid Lilo

• Iyipada Cyanide si HCN: The amount of sulfuric acid needed to convert cyanide in wastewater into HCN depends on the concentration of cyanide in the wastewater. For example, to treat 1 m³ of wastewater with a fojusi cyanide of 5000 ppm, a certain quantity of sulfuric acid is required for this conversion.

• Ìsọdipúpọ̀ Omi Ẹ̀gbin : Yàtọ̀ sí ásíìdì fún ìyípadà cyanide, a tún lo ásíìdì afikún láti ṣàtúnṣe omi ẹ̀gbin sí ìwọ̀n ásíìdì tó tọ́. Iye tí a nílò láti dín pH kù sí ìsàlẹ̀ 2 jẹ́ kókó pàtàkì kan.

• Ìbáṣepọ̀ pẹ̀lú Alkali nínú Omi Ẹ̀gbin : Ó ṣeé ṣe kí àwọn ohun alkaline kan wà nínú omi ẹ̀gbin tí wọ́n máa ń ṣe àbájáde pẹ̀lú sulfuric acid, ṣùgbọ́n ní gbogbogbòò, ìwọ̀n tí a ń lò yìí kéré ní ìfiwéra pẹ̀lú iye tí a ń lò fún ìyípadà cyanide àti ìfọ́ acid.

• Ifesi pẹlu Carbonate ni Egbin: If the cyanide - containing ogidi nkans have a high erogbaate content, such as in some Cyanide tailings slurry, the carbonate will react with the acid to form carbon dioxide. In such cases, the sulfuric acid consumption will increase significantly, and these ohun elo may not be ideal for treatment by the acid - recovery method.

2.Alkali Lilo: onisuga caustic (NaOH) is used in the alkali absorption tower to absorb HCN and form NaCN. The amount of NaOH consumed is related to the amount of HCN generated and the absorption ṣiṣe.

3.Lime Lilo: In some cases, lime may be used in the subsequent treatment of wastewater, like adjusting the pH value for heavy metal precipitation. The amount of lime needed depends on the type and concentration of heavy metals in the wastewater and the required pH atunṣe ibiti o.

4. Ina ati Lilo Ooru : Awọn ẹrọ bii awọn fifa ina, awọn afẹ́fẹ́, ati awọn afẹ́fẹ́ centrifugal vacuum lo ina ina lakoko ilana naa. Ni igba otutu, nigbati a ba n gbona omi idọti tẹlẹ, a maa lo eeru lati mu iwọn otutu soke si ipele ti o yẹ fun iṣe naa.

ipari

The acidification recovery method for cyanide - containing wastewater to recover soda cyanide and heavy metals is a comprehensive and effective treatment technology. By following specific process steps, it can not only remove majele cyanide and heavy metals from wastewater but also recycle valuable resources. Although there are certain material and energy consumptions in the process, considering its envIronopolo ati Awọn anfani Aje, it has broad application prospects in the treatment of cyanide - containing wastewater. However, in actual operation, strict Awọn Ilana Abo need to be taken due to the oro of HCN gas. At the same time, continuous optimization of the process parameters is required to improve the recovery efficiency and din awọn idiyele.