Kaip turėtume išgauti auksą su natrio cianidu?

INįvadas

Geriausios atsigavimas of auksas naudojant natrio cianidas is a widely - adopted method in the Kasybos bei Taurieji metalai pramonės šakos. Cianidas has a unique ability to form tirpus complexes with gold, which allows for the extraction of gold from various sources, such as Žemos kokybės rūdos, tailings, and certain electronic waste. However, due to the Didelis toksiškumas of Cianidas, this process must be carried out with extreme caution and strict Laikymasis su saugumas bei aplinkaal regulations.

ikiKIPle iš aukso atgavimas su Natrio cianidas

In its natural state, gold is often found mixed with other naudingosios iškasenos in ores. When Natrio cianidas is introduced to gold - bearing ore, a Cheminė reakcija takes place. In the presence of oxygen and vanduo, gold reacts with cianidas to form a soluble compound. This reakcija effectively dissolves the gold within the cianido tirpalasatskiriaalavasg it from the other insoluble naudingosios iškasenos in the ore.

Žingsnis po žingsnio procesas

Rūdos paruošimas

1. Smulkinimo bei šlifavimas: The initial step involves reducing the size of the ore. Large ore chunks are first crushed into sMAller pieces using crushers. Subsequently, the crushed ore is ground into a fine powder in mills. This increases the surface area of the ore, enabling more efficient contact between the gold - containing particles and the cyanide solution. For example, in a typical aukso kasykla, the ore might be crushed to a size of less than 10 mm during the primary crushing stage and then ground to a particle size where approximately 80% of the particles are less than 75 micrometers in the grinding stage.

2. Išankstinis apdorojimas (jei reikia): If the ore contains Sulfido mineralai or other impurities that could impede the cyanide išplovimas process, pre - treatment becomes necessary. For instance, when there are substantial amounts of piritas in the ore, it can consume oxygen and cyanide, reducing the efektyvumas of Aukso gavyba. In such situations, the ore may undergo roasalavasg or bio - oksidacija. Roasting entails HEAting the ore in the presence of air to oxidize the sulfidiniai mineralai, while bio - oxidation utilizes specific bacteria to oxidize the sulfide naudingosios iškasenos at a lower temperature in a more aplinkai draugiškas būdas.

Išplovimas

1. Cianido tirpalo paruošimasPraskiestas tirpalas Natrio cianidas is prepared. The concentration of the cyanide solution generally ranges from 0.05% to 0.2% (w/v), depending on the characteristics of the ore and the gold content. kalkės is frequently added to the cyanide solution to adjust the pH to a range of 10 - 11. This šarminis envgeležiesment helps prevent the formation of nuodingasvandenilio cianido dujos and also promotes the dissolution of gold.

2. išplovimo procesas: The ground ore is then mixed with the cyanide solution in large tanks or through a heap - išplovimas nustatytiUP. In tank leAking, the ore - cyanide mixture is agitated, either MEChanically or by air injection, to ensure good contact between the gold - bearing particles and the cyanide, thereby increasing the reaction rate. In Krūvos išplovimas, which is more suitable for low - grade ores, the crushed ore is piled on an impermeable liner, and the cyanide solution is sprayed over the heap. The solution seeps through the ore, dissolving the gold as it progresses. The Išplovimo procesas can last anywhere from several hours to several days, depending on factors such as the type of ore, particle size, and leaching conditions.

atskyrimas of Solids and Liquids

Po Išplovimo procesas, the resulting slurry consists of solid waste (tailings) and a solution containing the gold - cyanide compound. Separating the solid and liquid components is crucial. This can be accomplished through methods like Filtravimas or Sedimentacija. In filtration, the slurry is passed through filter media, such as filter cloths or filter presses. The solid tailings are retained on the filter, while the clear solution, known as the pregnant solution, which contains the dissolved gold, passes through. Sedimentation involves allowing the solid particles to settle at the bottom of a tank due to gravity. The supernatant liquid, the pregnant solution, can then be carefully poured off.

aukso atgavimas from the Pregnant Solution

1. cinkas Precipitation (Merrill - Crowe Process): One common approach to recovering gold from the pregnant solution is cinkas precipitation. Zinc dust or zinc shavings are added to the solution. Since zinc is more reactive than gold, it displaces the gold from the gold - cyanide compound. The gold then precipitates out as a solid, along with some impurities. After the reaction, the solid precipitate is filtered and further processed. The resulting gold - containing solid is then smelted to obtain pure gold.

2. Aktyvintos anglies adsorbcija (Carbon - in - plaušiena/CIP and Carbon - in - Leach/CIL): Viduje CIP procesas, aktyvuota Anglis is added to the slurry after the leaching stage. The aktyvuota anglis, with its high surface area, adsorbs the gold - cyanide compound from the solution. The carbon - gold compound is then separated from the slurry by screening. In the CIL procesas, Aktyvuota anglis is added during the leaching process itself. The gold - loaded carbon is subsequently removed from the system. The gold can be extracted from the carbon using a strong cyanide solution or other extracting agents. After extraction, the gold can be recovered from the extracting solution through methods such as electrowinning or further precipitation.

Tobulinimas

The gold obtained after precipitation or Adsorbcija is usually not pure, containing impurities like other metals and non - metals. To obtain high - grynumas gold (usually 99.9% or higher), refining Procesai are employed. One common refining method is electrolytic refining. In this process, the impure gold is placed as the anode in an electrolytic cell, and a pure gold cathode is used. A suitable electrolyte, such as a solution of gold chloridas, is utilized. When an electric current passes through the cell, the gold in the anode dissolves and deposits on the cathode. The impurities either remain in the electrolyte or form a sludge at the bottom of the cell.

Saugumas ir aplinkageležiesmental Considerations

1. toksiškumas of Cyanide: Natrio cianidas is extremely toxic. Inhalation, ingestion, or skin contact with cyanide can be mirtinas, Visi operacijos involving cyanide must be conducted in well - ventilated areas, and workers must wear appropriate Asmeninės apsaugos priemonės, Įskaitant respiratoriuss, gloves, and protective clothing. Reagavimo į ekstremalias situacijas plans should be in place in case of cyanide spills or poveikiss.

2. poveikio aplinkai: Cyanide can be harmful to the envGeležisment if not properly managed. Tailings from the aukso atgavimas process may contain residual cyanide. These tailings must be stored in secure impoundments to prevent the release of cyanide into the environment. Gydymo metodai, Pavyzdžiui, Cheminė oksidacija arba biologinis °radation, can be used to break down the cyanide in the tailings before their release or disposal. Additionally, strict monitoring of water sources near Aukso atkūrimas operations is essential to ensure that no cyanide contamination occurs.

Išvada

Naudojimas Natrio cianidas to recover gold is a complex but effective process. It involves multiple steps, from ore preparation to gold recovery and refining. While it offers a high - efficiency way to extract gold from various sources, the associated saugusty ir Rizika aplinkais must be carefully managed. By following proper procedūros, using appropriate technology, and complying with regulations, the gold recovery pramonė can continue to operate in a sustainable and responsible manner.