Wednesday, December 14, 2011

Gold Treatment With Sulfuric Acid

Gold treatment with sulfuric acid is the process of dissolution of metals such as zinc, iron and other metal impurities using dilute sulfuric acid (H2SO4) and of the acid treatment process will be easier to concentrate on the stage before the phase of purification of the melting process for making pure gold, because. metallic impurities such as zinc, iron and other impurities that are integrated with the content of gold ore has been dissolved by liquid sulfuric acid (H2SO4). The process of Acid Treatment on gold is very important to do before proceeding to the gold metal smelting process, due to deposition of the cementation process is carried out is still a lot of metal-containing zinc, iron and tin are also entrained. In the use of dilute sulfuric acid (H2SO4) is a blend of metal impurities will easily soluble by dilute sulfuric acid (H2SO4), is a metal that has a positive electrode potential in electrochemical series is rather difficult to dissolve, because the greater the tendency to become ions, and vice versa. A metal with a more negative potential shifts the metal underneath any of the salt solution. Sulfuric acid (sulphuric acid) is a highly corrosive strong mineral acid with the molecular formula H2SO4. The historical name of this acid is oil of vitriol. The sulfuric acid is a colorless to slightly yellow liquid which is clear or viscous and is soluble in water at all concentrations. It is a dibasic acid. The corrosiveness of it is mainly due to its strong acidic nature, strong dehydrating property and if concentrated strong oxidizing property.
The same thing applies when reacting sulfuric acid with potassium nitrate. This reaction will produce nitric acid and precipitate potassium bisulfate When combined with sulfuric acid nitric acid behaves as an acid as well as substance to dehydrate, forming nitronium NO2 + ion, which is important in nitration reactions involving electrophilic substitution aroma. Reactions of this type is very important in organic chemistry. Sulfuric acid reacts with most metals via a single replacement reaction, which produces hydrogen gas and metal sulfates. Dilute H2SO4 will attack the iron, aluminum, zinc, manganese, magnesium and nickel, but reactions with tin and copper require hot sulfuric acid and concentrated. Lead and tungsen not react with sulfuric acid. The reaction between sulfuric acid with metals normally would produce hydrogen as shown in the equation below. But the reaction with tin dioxide than will produce hydrogen sulfide.

Fe (s) + H2SO4 (aq) → H2 (g) + FeSO4 (aq)

Sn (s) + 2 H2SO4 (aq) → SnSO4 (aq) + 2 H2O (l) + SO2 (g)

This is because the hot concentrated acid generally act as oxidizing agents, acid when dilute acids act as usual. So when the hot concentrated acid reacts with zinc, tin, and copper, it will produce a salt, water and sulfur dioxide, when the dilute acid which react with metals such as zinc will produce salt and hydrogen.So magnesium, aluminum, and silver. is a metal with a potential positive standard can dissolve well only on the nature oxidizing acid such as nitric acid (HNO3) Electrochemical Series: Li, K, Na, Mg, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn , Pb, H, Cu, Hg, Ag, Pd, Au, Pt. Metals are located to the left of hydrogen (H) has a negative electrochemical potential, while the right of the hydrogen has a positive electrode potential.

0 comments:

Post a Comment