Mist

 Mist or Fog is a phenomenon caused by small water droplets floating in the air. Physically, this is an example of  dispersion. It is most commonly seen in places where warm, moist air is suddenly cooled, such as when exhaling in winter or pouring water over a hot stove in a sauna. If the humidity and temperature conditions are suitable, it can be artificially made using an aerosol can. It can also occur as part of natural weather when moist air cools quickly, especially when the air comes into contact with a surface that is much cooler than the air.

 Like other suspensions, mist formation is greatly aided by the presence of nucleation sites where the suspended aqueous phase can solidify. Therefore, even anomalous sources such  as small particles from volcanic eruptions, emission of  polar gasses, and aurora-related magnetospheric ions  can cause nebula formation under appropriate conditions. Mist is often confused with fog, which commonly resembles a stratus cloud  lying on the ground level. These two phenomena are different, but there are some similarities. A similar process forms both fog and haze. The fog is thicker and generally lasts longer, but the mist is thinner and more transparent.

Smoke

Smoke is a collection of particles and gas in the air that are emitted when a substance is burned or pyrolyzed, and is generated with the amount of air that accompanies or mixes with the mass. This is generally an unwanted by-product of fire (stove, candle, internal combustion engine, kerosene lamp, fireplace, etc.), but it can also be used for pest control (fumigation), communication (smoke signal), defense and attack functions. Defensive capabilities in the military (smoke screen), cooking, or smoking (cigarettes, cannabis, etc.). It is used in rituals that burn incense, sage, or resin  to create an odour for spiritual or magical purposes. It can also be used as a fragrance or preservative. Smoke inhalation is the leading cause of death for victims of indoor fires. Smoke kills  by a combination of heat damage, poisoning, and lung inflammation caused by carbon monoxide, hydrocyanic acid, and other combustion products.  Smoke is an aerosol (or mist) of solid particles and  droplets that is close to the ideal size range  for Mie scattering of visible light.

Acid mist formation 

In copper electrowinning, a direct electric current  is passed between an anode and a cathode  immersed in a copper-rich solution. At the inert anode, water molecules are electrolyzed and oxygen bubbles are  formed on the surface of the anode. These oxygen bubbles grow  and eventually break away from the surface and rise through the bulk of the solution. These bubbles burst at the free surface of the solution and produce strongly acidic droplets, fines of which become airborne and form an acid mist throughout the electrowinning plant tankhouse. Acid mist is highly corrosive and will corrode cathode plates, anode hanger bars, tank house equipment and  building structures. Acid mist also poses a serious health hazard, causing extreme skin, eye and respiratory discomfort to tank house workers.

Effects of current density on acid mist

The current density with an R2 value of 0.014 was the fourth influencing parameter on the amount of acid mist generated. In absolute  terms, the effect of current density on the acid mist is much less than that of temperature and based on  Cohen’s classification, the effect of current density is considered small. However, the current density is an important factor in relative terms, as the amount of acid mist generated at 400 A m2 was 34% higher than that generated at 200 A m2 . To compare how much current density and FC-1100  affect the amount of acid mist produced, the average acid mist measurements at  various current densities were plotted with and without the presence of FC-1100. The results again confirm a significant reduction in acid mist at both low and high current densities when FC-1100 is added to the electrolyte solution. Since there is no significant difference in the slope of the two lines , this means that the current density has no significant impact on the effect of FC-1100 on acid mist generation, i.e. little interaction effect between current density and FC-1100 . Regardless of the presence of FC-1100, increasing the current density increases the amount of acid mist generated. However, the amount of acid did not double when the current density was doubled. This is because acid mist is generated from the bursting of bubbles which eject droplets into the air, some of which are carried into the air.

Conclusion

Mist or Fog are small water droplets floating in the air. These droplets form when warm water in the air cools rapidly, turning invisible gasses into tiny, visible  droplets. Fog often forms when warm air over water suddenly collides with cold land. Fog begins to form when water vapor condenses into small liquid  droplets suspended in the air. When the sky is clear at night, the Earth’s surface is cool because it radiates heat into space. However, the surface of seas and lakes does not cool  more than a small amount (less than 1°C) overnight. When the air in contact with the surface cools to its dew point temperature,  droplets form.