I don't know if big data detected my recent "lack of gold", crazy let me brush to the video about refining gold and silver, most of them are extracted from industrial waste or gold-plated jewelry, as little as one gram, as much as dozens of hundreds of grams, it is difficult not to be moved.
But is gold really that easy to come by? Next, I hope you can read this article patiently and don't easily follow the trend.
Aqua regia + reducing agent method
In the gold-containing waste, aqua regia (volume ratio of 3:1 concentrated hydrochloric acid and concentrated nitric acid), dissolved and filtered, the filtrate is heated and boiled, in the process a small amount of dilute hydrochloric acid is added many times, so that the nitrogen oxide gas escapes (commonly known as catching nitrogen).
The gold-containing waste aqua regia drops are added to the excess sodium sulfite solution to reduce the gold. (The headline edit formula shows that it is too long, only important reactant products are marked, and it is not leveled)
At this time, large particles of yellow sponge gold have been produced, and a small amount of polyvinyl alcohol has been added as a coagulant to make the floating gold powder settle. Finally, the precipitate is washed with water and burned at high temperature to obtain coarse gold.
Cyanide + zinc wire replacement method
Experimental operation level: I searched for a large number of related short videos to watch, as mentioned in the comments section, also as a person with a chemical background, blood pressure is from start to finish. Many operators do not have professional knowledge, especially dangerous chemical experiments, but the whole video can even be counted as a negative teaching material. For example, using a thermometer as a glass rod to stir, resulting in the explosion of the thermometer; for example, instead of using a standard filter device, but holding the filter paper with a hand without any protection, catching the beaker and directly dumping the solution, is this really not afraid of hand corrosion? Or is it that the ignorant are fearless?
Wrong to the edge of the filtering operation
Waste liquid treatment level: There is not a video showing how the used waste liquid is treated after the "alchemy" is completed. Ordinary people still know that industrial wastewater cannot be discharged at will without treatment, and there are people in the comment area of the bullet curtain area asking how to treat the waste liquid, but there is no answer. So, is it really throwing the waste residue in the trash and the waste liquid draining the sewer?
Numerous questions went unanswered
Viewer level: It is not recommended that primary and secondary school students watch such videos, really want to watch is also in the chemistry class, by the teacher to take out the students to correct the error; not to mention that ordinary people in order to "alchemy" really to imitate, not exaggerated to say, chemical experiment operation specifications are in exchange for how much blood and tears, others did not have an accident is not because he is correct, but is still in fluke. Remember the "Office Ono" can incident? The two girls imitated the video of making popcorn from cans, and as a result, they exploded just after lighting alcohol, resulting in one death and one injury, which was very painful.
Accident scene
Many people may feel that after watching these videos, they feel that there is gold everywhere, but they have missed the opportunity to "turn waste into treasure". However, it should be known that ordinary people cannot contact these large amounts of gold-containing silver waste, and the gold content of daily electronic products is not enough to bear the cost of refining. Just remember, if there are computers and mobile phones that have been eliminated at home, don't throw them in the trash, and it is still good to sell them to the waste recycling office to earn some pocket money.
Gold-containing raw materials: wastewater comes from the electroplating workshop of the electronic factory and the jewelry factory; the waste comes from the electroplating scrap material, gold-plated electronic pin, gold-plated thimble pin of the electronic factory, the waste of the jewelry factory, anode mud, gold wire, etc.; as well as our daily scrapped computer motherboards, mobile phone motherboards, memory sticks, cartridges and toner cartridges.
Contains gold scrap
Silver-containing raw materials: waste fixing fluid and waste film from photo studios, waste CT films and X-rays from the radiology department of hospitals, waste water from printing plants, waste film sheets, various silver plating parts, silver electrodes and silver-containing reagents.
Contains silver scrap
Gold: Generally use the fire to remove the grease, and then put the hot gold into the hydrochloric acid to clean. It should be noted that some unscrupulous traders will secretly exchange hydrochloric acid for aqua regia to steal customers' gold, so it is best to weigh and compare before and after maintenance.
Silverware: First wash the silverware with dish soap, remove the grease, and then find an aluminum foil, and put it in salt water at about 80 ° C with the silverware, after 3-5 minutes, the silverware will be smooth as new.